linux-stable/drivers/net/ethernet/sfc/rx.c

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// SPDX-License-Identifier: GPL-2.0-only
/****************************************************************************
* Driver for Solarflare network controllers and boards
* Copyright 2005-2006 Fen Systems Ltd.
* Copyright 2005-2013 Solarflare Communications Inc.
*/
#include <linux/socket.h>
#include <linux/in.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#include <linux/slab.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/prefetch.h>
#include <linux/moduleparam.h>
sfc: reuse pages to avoid DMA mapping/unmapping costs On POWER systems, DMA mapping/unmapping operations are very expensive. These changes reduce these costs by trying to reuse DMA mapped pages. After all the buffers associated with a page have been processed and passed up, the page is placed into a ring (if there is room). For each page that is required for a refill operation, a page in the ring is examined to determine if its page count has fallen to 1, ie. the kernel has released its reference to these packets. If this is the case, the page can be immediately added back into the RX descriptor ring, without having to re-map it for DMA. If the kernel is still holding a reference to this page, it is removed from the ring and unmapped for DMA. Then a new page, which can immediately be used by RX buffers in the descriptor ring, is allocated and DMA mapped. The time a page needs to spend in the recycle ring before the kernel has released its page references is based on the number of buffers that use this page. As large pages can hold more RX buffers, the RX recycle ring can be shorter. This reduces memory usage on POWER systems, while maintaining the performance gain achieved by recycling pages, following the driver change to pack more than two RX buffers into large pages. When an IOMMU is not present, the recycle ring can be small to reduce memory usage, since DMA mapping operations are inexpensive. With a small recycle ring, attempting to refill the descriptor queue with more buffers than the equivalent size of the recycle ring could ultimately lead to memory leaks if page entries in the recycle ring were overwritten. To prevent this, the check to see if the recycle ring is full is changed to check if the next entry to be written is NULL. [bwh: Combine and rebase several commits so this is complete before the following buffer-packing changes. Remove module parameter.] Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2013-02-13 10:54:41 +00:00
#include <linux/iommu.h>
#include <net/ip.h>
#include <net/checksum.h>
#include <net/xdp.h>
#include <linux/bpf_trace.h>
#include "net_driver.h"
#include "efx.h"
#include "filter.h"
#include "nic.h"
#include "selftest.h"
#include "workarounds.h"
/* Preferred number of descriptors to fill at once */
#define EFX_RX_PREFERRED_BATCH 8U
/* Maximum rx prefix used by any architecture. */
#define EFX_MAX_RX_PREFIX_SIZE 16
sfc: reuse pages to avoid DMA mapping/unmapping costs On POWER systems, DMA mapping/unmapping operations are very expensive. These changes reduce these costs by trying to reuse DMA mapped pages. After all the buffers associated with a page have been processed and passed up, the page is placed into a ring (if there is room). For each page that is required for a refill operation, a page in the ring is examined to determine if its page count has fallen to 1, ie. the kernel has released its reference to these packets. If this is the case, the page can be immediately added back into the RX descriptor ring, without having to re-map it for DMA. If the kernel is still holding a reference to this page, it is removed from the ring and unmapped for DMA. Then a new page, which can immediately be used by RX buffers in the descriptor ring, is allocated and DMA mapped. The time a page needs to spend in the recycle ring before the kernel has released its page references is based on the number of buffers that use this page. As large pages can hold more RX buffers, the RX recycle ring can be shorter. This reduces memory usage on POWER systems, while maintaining the performance gain achieved by recycling pages, following the driver change to pack more than two RX buffers into large pages. When an IOMMU is not present, the recycle ring can be small to reduce memory usage, since DMA mapping operations are inexpensive. With a small recycle ring, attempting to refill the descriptor queue with more buffers than the equivalent size of the recycle ring could ultimately lead to memory leaks if page entries in the recycle ring were overwritten. To prevent this, the check to see if the recycle ring is full is changed to check if the next entry to be written is NULL. [bwh: Combine and rebase several commits so this is complete before the following buffer-packing changes. Remove module parameter.] Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2013-02-13 10:54:41 +00:00
/* Number of RX buffers to recycle pages for. When creating the RX page recycle
* ring, this number is divided by the number of buffers per page to calculate
* the number of pages to store in the RX page recycle ring.
*/
#define EFX_RECYCLE_RING_SIZE_IOMMU 4096
#define EFX_RECYCLE_RING_SIZE_NOIOMMU (2 * EFX_RX_PREFERRED_BATCH)
/* Size of buffer allocated for skb header area. */
#define EFX_SKB_HEADERS 128u
/* This is the percentage fill level below which new RX descriptors
* will be added to the RX descriptor ring.
*/
static unsigned int rx_refill_threshold;
/* Each packet can consume up to ceil(max_frame_len / buffer_size) buffers */
#define EFX_RX_MAX_FRAGS DIV_ROUND_UP(EFX_MAX_FRAME_LEN(EFX_MAX_MTU), \
EFX_RX_USR_BUF_SIZE)
/*
* RX maximum head room required.
*
* This must be at least 1 to prevent overflow, plus one packet-worth
* to allow pipelined receives.
*/
#define EFX_RXD_HEAD_ROOM (1 + EFX_RX_MAX_FRAGS)
static inline u8 *efx_rx_buf_va(struct efx_rx_buffer *buf)
{
return page_address(buf->page) + buf->page_offset;
}
static inline u32 efx_rx_buf_hash(struct efx_nic *efx, const u8 *eh)
{
#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
return __le32_to_cpup((const __le32 *)(eh + efx->rx_packet_hash_offset));
#else
const u8 *data = eh + efx->rx_packet_hash_offset;
return (u32)data[0] |
(u32)data[1] << 8 |
(u32)data[2] << 16 |
(u32)data[3] << 24;
#endif
}
static inline struct efx_rx_buffer *
efx_rx_buf_next(struct efx_rx_queue *rx_queue, struct efx_rx_buffer *rx_buf)
{
if (unlikely(rx_buf == efx_rx_buffer(rx_queue, rx_queue->ptr_mask)))
return efx_rx_buffer(rx_queue, 0);
else
return rx_buf + 1;
}
sfc: reuse pages to avoid DMA mapping/unmapping costs On POWER systems, DMA mapping/unmapping operations are very expensive. These changes reduce these costs by trying to reuse DMA mapped pages. After all the buffers associated with a page have been processed and passed up, the page is placed into a ring (if there is room). For each page that is required for a refill operation, a page in the ring is examined to determine if its page count has fallen to 1, ie. the kernel has released its reference to these packets. If this is the case, the page can be immediately added back into the RX descriptor ring, without having to re-map it for DMA. If the kernel is still holding a reference to this page, it is removed from the ring and unmapped for DMA. Then a new page, which can immediately be used by RX buffers in the descriptor ring, is allocated and DMA mapped. The time a page needs to spend in the recycle ring before the kernel has released its page references is based on the number of buffers that use this page. As large pages can hold more RX buffers, the RX recycle ring can be shorter. This reduces memory usage on POWER systems, while maintaining the performance gain achieved by recycling pages, following the driver change to pack more than two RX buffers into large pages. When an IOMMU is not present, the recycle ring can be small to reduce memory usage, since DMA mapping operations are inexpensive. With a small recycle ring, attempting to refill the descriptor queue with more buffers than the equivalent size of the recycle ring could ultimately lead to memory leaks if page entries in the recycle ring were overwritten. To prevent this, the check to see if the recycle ring is full is changed to check if the next entry to be written is NULL. [bwh: Combine and rebase several commits so this is complete before the following buffer-packing changes. Remove module parameter.] Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2013-02-13 10:54:41 +00:00
static inline void efx_sync_rx_buffer(struct efx_nic *efx,
struct efx_rx_buffer *rx_buf,
unsigned int len)
{
dma_sync_single_for_cpu(&efx->pci_dev->dev, rx_buf->dma_addr, len,
DMA_FROM_DEVICE);
}
void efx_rx_config_page_split(struct efx_nic *efx)
{
efx->rx_page_buf_step = ALIGN(efx->rx_dma_len + efx->rx_ip_align,
sfc: Reduce RX scatter buffer size, and reduce alignment if appropriate efx_start_datapath() asserts that we can fit 2 RX scatter buffers plus a software structure, each appropriately aligned, into a single page. Where L1_CACHE_BYTES == 256 and PAGE_SIZE == 4096, which is the case on s390, this assertion fails. The current scatter buffer size is also not a multiple of 64 or 128, which are more common cache line sizes. If we can make both the start and end of a scatter buffer cache-aligned, this will reduce the need for read-modify-write operations on inter- processor links. Fix the alignment by reducing EFX_RX_USR_BUF_SIZE to 2048 - 256 == 1792. (We could use 2048 - L1_CACHE_BYTES, but EFX_RX_USR_BUF_SIZE also affects user-level networking where a larger amount of housekeeping data may be needed. Although this version of the driver does not support user-level networking, I prefer to keep scattering behaviour consistent with the out-of-tree version.) This still doesn't fix the s390 build because like most architectures it has NET_IP_ALIGN == 2. When NET_IP_ALIGN != 0 we cannot achieve cache line alignment at either the start or end of a scatter buffer, so there is actually no point in padding the buffers to a multiple of the cache line size. All we need is 4-byte alignment of the network header, so do that. Adjust the assertions accordingly. Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Ben Hutchings <bhutchings@solarflare.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-05-13 12:01:22 +00:00
EFX_RX_BUF_ALIGNMENT);
efx->rx_bufs_per_page = efx->rx_buffer_order ? 1 :
((PAGE_SIZE - sizeof(struct efx_rx_page_state)) /
(efx->rx_page_buf_step + XDP_PACKET_HEADROOM));
efx->rx_buffer_truesize = (PAGE_SIZE << efx->rx_buffer_order) /
efx->rx_bufs_per_page;
efx->rx_pages_per_batch = DIV_ROUND_UP(EFX_RX_PREFERRED_BATCH,
efx->rx_bufs_per_page);
}
sfc: reuse pages to avoid DMA mapping/unmapping costs On POWER systems, DMA mapping/unmapping operations are very expensive. These changes reduce these costs by trying to reuse DMA mapped pages. After all the buffers associated with a page have been processed and passed up, the page is placed into a ring (if there is room). For each page that is required for a refill operation, a page in the ring is examined to determine if its page count has fallen to 1, ie. the kernel has released its reference to these packets. If this is the case, the page can be immediately added back into the RX descriptor ring, without having to re-map it for DMA. If the kernel is still holding a reference to this page, it is removed from the ring and unmapped for DMA. Then a new page, which can immediately be used by RX buffers in the descriptor ring, is allocated and DMA mapped. The time a page needs to spend in the recycle ring before the kernel has released its page references is based on the number of buffers that use this page. As large pages can hold more RX buffers, the RX recycle ring can be shorter. This reduces memory usage on POWER systems, while maintaining the performance gain achieved by recycling pages, following the driver change to pack more than two RX buffers into large pages. When an IOMMU is not present, the recycle ring can be small to reduce memory usage, since DMA mapping operations are inexpensive. With a small recycle ring, attempting to refill the descriptor queue with more buffers than the equivalent size of the recycle ring could ultimately lead to memory leaks if page entries in the recycle ring were overwritten. To prevent this, the check to see if the recycle ring is full is changed to check if the next entry to be written is NULL. [bwh: Combine and rebase several commits so this is complete before the following buffer-packing changes. Remove module parameter.] Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2013-02-13 10:54:41 +00:00
/* Check the RX page recycle ring for a page that can be reused. */
static struct page *efx_reuse_page(struct efx_rx_queue *rx_queue)
{
struct efx_nic *efx = rx_queue->efx;
struct page *page;
struct efx_rx_page_state *state;
unsigned index;
index = rx_queue->page_remove & rx_queue->page_ptr_mask;
page = rx_queue->page_ring[index];
if (page == NULL)
return NULL;
rx_queue->page_ring[index] = NULL;
/* page_remove cannot exceed page_add. */
if (rx_queue->page_remove != rx_queue->page_add)
++rx_queue->page_remove;
/* If page_count is 1 then we hold the only reference to this page. */
if (page_count(page) == 1) {
++rx_queue->page_recycle_count;
return page;
} else {
state = page_address(page);
dma_unmap_page(&efx->pci_dev->dev, state->dma_addr,
PAGE_SIZE << efx->rx_buffer_order,
DMA_FROM_DEVICE);
put_page(page);
++rx_queue->page_recycle_failed;
}
return NULL;
}
/**
* efx_init_rx_buffers - create EFX_RX_BATCH page-based RX buffers
*
* @rx_queue: Efx RX queue
*
* This allocates a batch of pages, maps them for DMA, and populates
* struct efx_rx_buffers for each one. Return a negative error code or
* 0 on success. If a single page can be used for multiple buffers,
* then the page will either be inserted fully, or not at all.
*/
static int efx_init_rx_buffers(struct efx_rx_queue *rx_queue, bool atomic)
{
struct efx_nic *efx = rx_queue->efx;
struct efx_rx_buffer *rx_buf;
struct page *page;
unsigned int page_offset;
struct efx_rx_page_state *state;
dma_addr_t dma_addr;
unsigned index, count;
count = 0;
do {
sfc: reuse pages to avoid DMA mapping/unmapping costs On POWER systems, DMA mapping/unmapping operations are very expensive. These changes reduce these costs by trying to reuse DMA mapped pages. After all the buffers associated with a page have been processed and passed up, the page is placed into a ring (if there is room). For each page that is required for a refill operation, a page in the ring is examined to determine if its page count has fallen to 1, ie. the kernel has released its reference to these packets. If this is the case, the page can be immediately added back into the RX descriptor ring, without having to re-map it for DMA. If the kernel is still holding a reference to this page, it is removed from the ring and unmapped for DMA. Then a new page, which can immediately be used by RX buffers in the descriptor ring, is allocated and DMA mapped. The time a page needs to spend in the recycle ring before the kernel has released its page references is based on the number of buffers that use this page. As large pages can hold more RX buffers, the RX recycle ring can be shorter. This reduces memory usage on POWER systems, while maintaining the performance gain achieved by recycling pages, following the driver change to pack more than two RX buffers into large pages. When an IOMMU is not present, the recycle ring can be small to reduce memory usage, since DMA mapping operations are inexpensive. With a small recycle ring, attempting to refill the descriptor queue with more buffers than the equivalent size of the recycle ring could ultimately lead to memory leaks if page entries in the recycle ring were overwritten. To prevent this, the check to see if the recycle ring is full is changed to check if the next entry to be written is NULL. [bwh: Combine and rebase several commits so this is complete before the following buffer-packing changes. Remove module parameter.] Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2013-02-13 10:54:41 +00:00
page = efx_reuse_page(rx_queue);
if (page == NULL) {
mm: remove __GFP_COLD As the page free path makes no distinction between cache hot and cold pages, there is no real useful ordering of pages in the free list that allocation requests can take advantage of. Juding from the users of __GFP_COLD, it is likely that a number of them are the result of copying other sites instead of actually measuring the impact. Remove the __GFP_COLD parameter which simplifies a number of paths in the page allocator. This is potentially controversial but bear in mind that the size of the per-cpu pagelists versus modern cache sizes means that the whole per-cpu list can often fit in the L3 cache. Hence, there is only a potential benefit for microbenchmarks that alloc/free pages in a tight loop. It's even worse when THP is taken into account which has little or no chance of getting a cache-hot page as the per-cpu list is bypassed and the zeroing of multiple pages will thrash the cache anyway. The truncate microbenchmarks are not shown as this patch affects the allocation path and not the free path. A page fault microbenchmark was tested but it showed no sigificant difference which is not surprising given that the __GFP_COLD branches are a miniscule percentage of the fault path. Link: http://lkml.kernel.org/r/20171018075952.10627-9-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Andi Kleen <ak@linux.intel.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-16 01:38:03 +00:00
page = alloc_pages(__GFP_COMP |
(atomic ? GFP_ATOMIC : GFP_KERNEL),
sfc: reuse pages to avoid DMA mapping/unmapping costs On POWER systems, DMA mapping/unmapping operations are very expensive. These changes reduce these costs by trying to reuse DMA mapped pages. After all the buffers associated with a page have been processed and passed up, the page is placed into a ring (if there is room). For each page that is required for a refill operation, a page in the ring is examined to determine if its page count has fallen to 1, ie. the kernel has released its reference to these packets. If this is the case, the page can be immediately added back into the RX descriptor ring, without having to re-map it for DMA. If the kernel is still holding a reference to this page, it is removed from the ring and unmapped for DMA. Then a new page, which can immediately be used by RX buffers in the descriptor ring, is allocated and DMA mapped. The time a page needs to spend in the recycle ring before the kernel has released its page references is based on the number of buffers that use this page. As large pages can hold more RX buffers, the RX recycle ring can be shorter. This reduces memory usage on POWER systems, while maintaining the performance gain achieved by recycling pages, following the driver change to pack more than two RX buffers into large pages. When an IOMMU is not present, the recycle ring can be small to reduce memory usage, since DMA mapping operations are inexpensive. With a small recycle ring, attempting to refill the descriptor queue with more buffers than the equivalent size of the recycle ring could ultimately lead to memory leaks if page entries in the recycle ring were overwritten. To prevent this, the check to see if the recycle ring is full is changed to check if the next entry to be written is NULL. [bwh: Combine and rebase several commits so this is complete before the following buffer-packing changes. Remove module parameter.] Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2013-02-13 10:54:41 +00:00
efx->rx_buffer_order);
if (unlikely(page == NULL))
return -ENOMEM;
dma_addr =
dma_map_page(&efx->pci_dev->dev, page, 0,
PAGE_SIZE << efx->rx_buffer_order,
DMA_FROM_DEVICE);
if (unlikely(dma_mapping_error(&efx->pci_dev->dev,
dma_addr))) {
__free_pages(page, efx->rx_buffer_order);
return -EIO;
}
state = page_address(page);
state->dma_addr = dma_addr;
} else {
state = page_address(page);
dma_addr = state->dma_addr;
}
dma_addr += sizeof(struct efx_rx_page_state);
page_offset = sizeof(struct efx_rx_page_state);
do {
page_offset += XDP_PACKET_HEADROOM;
dma_addr += XDP_PACKET_HEADROOM;
index = rx_queue->added_count & rx_queue->ptr_mask;
rx_buf = efx_rx_buffer(rx_queue, index);
rx_buf->dma_addr = dma_addr + efx->rx_ip_align;
rx_buf->page = page;
rx_buf->page_offset = page_offset + efx->rx_ip_align;
rx_buf->len = efx->rx_dma_len;
rx_buf->flags = 0;
++rx_queue->added_count;
get_page(page);
dma_addr += efx->rx_page_buf_step;
page_offset += efx->rx_page_buf_step;
} while (page_offset + efx->rx_page_buf_step <= PAGE_SIZE);
rx_buf->flags = EFX_RX_BUF_LAST_IN_PAGE;
} while (++count < efx->rx_pages_per_batch);
return 0;
}
sfc: reuse pages to avoid DMA mapping/unmapping costs On POWER systems, DMA mapping/unmapping operations are very expensive. These changes reduce these costs by trying to reuse DMA mapped pages. After all the buffers associated with a page have been processed and passed up, the page is placed into a ring (if there is room). For each page that is required for a refill operation, a page in the ring is examined to determine if its page count has fallen to 1, ie. the kernel has released its reference to these packets. If this is the case, the page can be immediately added back into the RX descriptor ring, without having to re-map it for DMA. If the kernel is still holding a reference to this page, it is removed from the ring and unmapped for DMA. Then a new page, which can immediately be used by RX buffers in the descriptor ring, is allocated and DMA mapped. The time a page needs to spend in the recycle ring before the kernel has released its page references is based on the number of buffers that use this page. As large pages can hold more RX buffers, the RX recycle ring can be shorter. This reduces memory usage on POWER systems, while maintaining the performance gain achieved by recycling pages, following the driver change to pack more than two RX buffers into large pages. When an IOMMU is not present, the recycle ring can be small to reduce memory usage, since DMA mapping operations are inexpensive. With a small recycle ring, attempting to refill the descriptor queue with more buffers than the equivalent size of the recycle ring could ultimately lead to memory leaks if page entries in the recycle ring were overwritten. To prevent this, the check to see if the recycle ring is full is changed to check if the next entry to be written is NULL. [bwh: Combine and rebase several commits so this is complete before the following buffer-packing changes. Remove module parameter.] Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2013-02-13 10:54:41 +00:00
/* Unmap a DMA-mapped page. This function is only called for the final RX
* buffer in a page.
*/
static void efx_unmap_rx_buffer(struct efx_nic *efx,
sfc: reuse pages to avoid DMA mapping/unmapping costs On POWER systems, DMA mapping/unmapping operations are very expensive. These changes reduce these costs by trying to reuse DMA mapped pages. After all the buffers associated with a page have been processed and passed up, the page is placed into a ring (if there is room). For each page that is required for a refill operation, a page in the ring is examined to determine if its page count has fallen to 1, ie. the kernel has released its reference to these packets. If this is the case, the page can be immediately added back into the RX descriptor ring, without having to re-map it for DMA. If the kernel is still holding a reference to this page, it is removed from the ring and unmapped for DMA. Then a new page, which can immediately be used by RX buffers in the descriptor ring, is allocated and DMA mapped. The time a page needs to spend in the recycle ring before the kernel has released its page references is based on the number of buffers that use this page. As large pages can hold more RX buffers, the RX recycle ring can be shorter. This reduces memory usage on POWER systems, while maintaining the performance gain achieved by recycling pages, following the driver change to pack more than two RX buffers into large pages. When an IOMMU is not present, the recycle ring can be small to reduce memory usage, since DMA mapping operations are inexpensive. With a small recycle ring, attempting to refill the descriptor queue with more buffers than the equivalent size of the recycle ring could ultimately lead to memory leaks if page entries in the recycle ring were overwritten. To prevent this, the check to see if the recycle ring is full is changed to check if the next entry to be written is NULL. [bwh: Combine and rebase several commits so this is complete before the following buffer-packing changes. Remove module parameter.] Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2013-02-13 10:54:41 +00:00
struct efx_rx_buffer *rx_buf)
{
sfc: reuse pages to avoid DMA mapping/unmapping costs On POWER systems, DMA mapping/unmapping operations are very expensive. These changes reduce these costs by trying to reuse DMA mapped pages. After all the buffers associated with a page have been processed and passed up, the page is placed into a ring (if there is room). For each page that is required for a refill operation, a page in the ring is examined to determine if its page count has fallen to 1, ie. the kernel has released its reference to these packets. If this is the case, the page can be immediately added back into the RX descriptor ring, without having to re-map it for DMA. If the kernel is still holding a reference to this page, it is removed from the ring and unmapped for DMA. Then a new page, which can immediately be used by RX buffers in the descriptor ring, is allocated and DMA mapped. The time a page needs to spend in the recycle ring before the kernel has released its page references is based on the number of buffers that use this page. As large pages can hold more RX buffers, the RX recycle ring can be shorter. This reduces memory usage on POWER systems, while maintaining the performance gain achieved by recycling pages, following the driver change to pack more than two RX buffers into large pages. When an IOMMU is not present, the recycle ring can be small to reduce memory usage, since DMA mapping operations are inexpensive. With a small recycle ring, attempting to refill the descriptor queue with more buffers than the equivalent size of the recycle ring could ultimately lead to memory leaks if page entries in the recycle ring were overwritten. To prevent this, the check to see if the recycle ring is full is changed to check if the next entry to be written is NULL. [bwh: Combine and rebase several commits so this is complete before the following buffer-packing changes. Remove module parameter.] Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2013-02-13 10:54:41 +00:00
struct page *page = rx_buf->page;
if (page) {
struct efx_rx_page_state *state = page_address(page);
dma_unmap_page(&efx->pci_dev->dev,
state->dma_addr,
PAGE_SIZE << efx->rx_buffer_order,
DMA_FROM_DEVICE);
}
}
static void efx_free_rx_buffers(struct efx_rx_queue *rx_queue,
struct efx_rx_buffer *rx_buf,
unsigned int num_bufs)
{
do {
if (rx_buf->page) {
put_page(rx_buf->page);
rx_buf->page = NULL;
}
rx_buf = efx_rx_buf_next(rx_queue, rx_buf);
} while (--num_bufs);
}
sfc: reuse pages to avoid DMA mapping/unmapping costs On POWER systems, DMA mapping/unmapping operations are very expensive. These changes reduce these costs by trying to reuse DMA mapped pages. After all the buffers associated with a page have been processed and passed up, the page is placed into a ring (if there is room). For each page that is required for a refill operation, a page in the ring is examined to determine if its page count has fallen to 1, ie. the kernel has released its reference to these packets. If this is the case, the page can be immediately added back into the RX descriptor ring, without having to re-map it for DMA. If the kernel is still holding a reference to this page, it is removed from the ring and unmapped for DMA. Then a new page, which can immediately be used by RX buffers in the descriptor ring, is allocated and DMA mapped. The time a page needs to spend in the recycle ring before the kernel has released its page references is based on the number of buffers that use this page. As large pages can hold more RX buffers, the RX recycle ring can be shorter. This reduces memory usage on POWER systems, while maintaining the performance gain achieved by recycling pages, following the driver change to pack more than two RX buffers into large pages. When an IOMMU is not present, the recycle ring can be small to reduce memory usage, since DMA mapping operations are inexpensive. With a small recycle ring, attempting to refill the descriptor queue with more buffers than the equivalent size of the recycle ring could ultimately lead to memory leaks if page entries in the recycle ring were overwritten. To prevent this, the check to see if the recycle ring is full is changed to check if the next entry to be written is NULL. [bwh: Combine and rebase several commits so this is complete before the following buffer-packing changes. Remove module parameter.] Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2013-02-13 10:54:41 +00:00
/* Attempt to recycle the page if there is an RX recycle ring; the page can
* only be added if this is the final RX buffer, to prevent pages being used in
* the descriptor ring and appearing in the recycle ring simultaneously.
*/
static void efx_recycle_rx_page(struct efx_channel *channel,
struct efx_rx_buffer *rx_buf)
{
sfc: reuse pages to avoid DMA mapping/unmapping costs On POWER systems, DMA mapping/unmapping operations are very expensive. These changes reduce these costs by trying to reuse DMA mapped pages. After all the buffers associated with a page have been processed and passed up, the page is placed into a ring (if there is room). For each page that is required for a refill operation, a page in the ring is examined to determine if its page count has fallen to 1, ie. the kernel has released its reference to these packets. If this is the case, the page can be immediately added back into the RX descriptor ring, without having to re-map it for DMA. If the kernel is still holding a reference to this page, it is removed from the ring and unmapped for DMA. Then a new page, which can immediately be used by RX buffers in the descriptor ring, is allocated and DMA mapped. The time a page needs to spend in the recycle ring before the kernel has released its page references is based on the number of buffers that use this page. As large pages can hold more RX buffers, the RX recycle ring can be shorter. This reduces memory usage on POWER systems, while maintaining the performance gain achieved by recycling pages, following the driver change to pack more than two RX buffers into large pages. When an IOMMU is not present, the recycle ring can be small to reduce memory usage, since DMA mapping operations are inexpensive. With a small recycle ring, attempting to refill the descriptor queue with more buffers than the equivalent size of the recycle ring could ultimately lead to memory leaks if page entries in the recycle ring were overwritten. To prevent this, the check to see if the recycle ring is full is changed to check if the next entry to be written is NULL. [bwh: Combine and rebase several commits so this is complete before the following buffer-packing changes. Remove module parameter.] Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2013-02-13 10:54:41 +00:00
struct page *page = rx_buf->page;
struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
struct efx_nic *efx = rx_queue->efx;
unsigned index;
sfc: reuse pages to avoid DMA mapping/unmapping costs On POWER systems, DMA mapping/unmapping operations are very expensive. These changes reduce these costs by trying to reuse DMA mapped pages. After all the buffers associated with a page have been processed and passed up, the page is placed into a ring (if there is room). For each page that is required for a refill operation, a page in the ring is examined to determine if its page count has fallen to 1, ie. the kernel has released its reference to these packets. If this is the case, the page can be immediately added back into the RX descriptor ring, without having to re-map it for DMA. If the kernel is still holding a reference to this page, it is removed from the ring and unmapped for DMA. Then a new page, which can immediately be used by RX buffers in the descriptor ring, is allocated and DMA mapped. The time a page needs to spend in the recycle ring before the kernel has released its page references is based on the number of buffers that use this page. As large pages can hold more RX buffers, the RX recycle ring can be shorter. This reduces memory usage on POWER systems, while maintaining the performance gain achieved by recycling pages, following the driver change to pack more than two RX buffers into large pages. When an IOMMU is not present, the recycle ring can be small to reduce memory usage, since DMA mapping operations are inexpensive. With a small recycle ring, attempting to refill the descriptor queue with more buffers than the equivalent size of the recycle ring could ultimately lead to memory leaks if page entries in the recycle ring were overwritten. To prevent this, the check to see if the recycle ring is full is changed to check if the next entry to be written is NULL. [bwh: Combine and rebase several commits so this is complete before the following buffer-packing changes. Remove module parameter.] Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2013-02-13 10:54:41 +00:00
/* Only recycle the page after processing the final buffer. */
if (!(rx_buf->flags & EFX_RX_BUF_LAST_IN_PAGE))
return;
sfc: reuse pages to avoid DMA mapping/unmapping costs On POWER systems, DMA mapping/unmapping operations are very expensive. These changes reduce these costs by trying to reuse DMA mapped pages. After all the buffers associated with a page have been processed and passed up, the page is placed into a ring (if there is room). For each page that is required for a refill operation, a page in the ring is examined to determine if its page count has fallen to 1, ie. the kernel has released its reference to these packets. If this is the case, the page can be immediately added back into the RX descriptor ring, without having to re-map it for DMA. If the kernel is still holding a reference to this page, it is removed from the ring and unmapped for DMA. Then a new page, which can immediately be used by RX buffers in the descriptor ring, is allocated and DMA mapped. The time a page needs to spend in the recycle ring before the kernel has released its page references is based on the number of buffers that use this page. As large pages can hold more RX buffers, the RX recycle ring can be shorter. This reduces memory usage on POWER systems, while maintaining the performance gain achieved by recycling pages, following the driver change to pack more than two RX buffers into large pages. When an IOMMU is not present, the recycle ring can be small to reduce memory usage, since DMA mapping operations are inexpensive. With a small recycle ring, attempting to refill the descriptor queue with more buffers than the equivalent size of the recycle ring could ultimately lead to memory leaks if page entries in the recycle ring were overwritten. To prevent this, the check to see if the recycle ring is full is changed to check if the next entry to be written is NULL. [bwh: Combine and rebase several commits so this is complete before the following buffer-packing changes. Remove module parameter.] Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2013-02-13 10:54:41 +00:00
index = rx_queue->page_add & rx_queue->page_ptr_mask;
if (rx_queue->page_ring[index] == NULL) {
unsigned read_index = rx_queue->page_remove &
rx_queue->page_ptr_mask;
sfc: reuse pages to avoid DMA mapping/unmapping costs On POWER systems, DMA mapping/unmapping operations are very expensive. These changes reduce these costs by trying to reuse DMA mapped pages. After all the buffers associated with a page have been processed and passed up, the page is placed into a ring (if there is room). For each page that is required for a refill operation, a page in the ring is examined to determine if its page count has fallen to 1, ie. the kernel has released its reference to these packets. If this is the case, the page can be immediately added back into the RX descriptor ring, without having to re-map it for DMA. If the kernel is still holding a reference to this page, it is removed from the ring and unmapped for DMA. Then a new page, which can immediately be used by RX buffers in the descriptor ring, is allocated and DMA mapped. The time a page needs to spend in the recycle ring before the kernel has released its page references is based on the number of buffers that use this page. As large pages can hold more RX buffers, the RX recycle ring can be shorter. This reduces memory usage on POWER systems, while maintaining the performance gain achieved by recycling pages, following the driver change to pack more than two RX buffers into large pages. When an IOMMU is not present, the recycle ring can be small to reduce memory usage, since DMA mapping operations are inexpensive. With a small recycle ring, attempting to refill the descriptor queue with more buffers than the equivalent size of the recycle ring could ultimately lead to memory leaks if page entries in the recycle ring were overwritten. To prevent this, the check to see if the recycle ring is full is changed to check if the next entry to be written is NULL. [bwh: Combine and rebase several commits so this is complete before the following buffer-packing changes. Remove module parameter.] Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2013-02-13 10:54:41 +00:00
/* The next slot in the recycle ring is available, but
* increment page_remove if the read pointer currently
* points here.
*/
if (read_index == index)
++rx_queue->page_remove;
rx_queue->page_ring[index] = page;
++rx_queue->page_add;
return;
}
++rx_queue->page_recycle_full;
efx_unmap_rx_buffer(efx, rx_buf);
put_page(rx_buf->page);
}
sfc: reuse pages to avoid DMA mapping/unmapping costs On POWER systems, DMA mapping/unmapping operations are very expensive. These changes reduce these costs by trying to reuse DMA mapped pages. After all the buffers associated with a page have been processed and passed up, the page is placed into a ring (if there is room). For each page that is required for a refill operation, a page in the ring is examined to determine if its page count has fallen to 1, ie. the kernel has released its reference to these packets. If this is the case, the page can be immediately added back into the RX descriptor ring, without having to re-map it for DMA. If the kernel is still holding a reference to this page, it is removed from the ring and unmapped for DMA. Then a new page, which can immediately be used by RX buffers in the descriptor ring, is allocated and DMA mapped. The time a page needs to spend in the recycle ring before the kernel has released its page references is based on the number of buffers that use this page. As large pages can hold more RX buffers, the RX recycle ring can be shorter. This reduces memory usage on POWER systems, while maintaining the performance gain achieved by recycling pages, following the driver change to pack more than two RX buffers into large pages. When an IOMMU is not present, the recycle ring can be small to reduce memory usage, since DMA mapping operations are inexpensive. With a small recycle ring, attempting to refill the descriptor queue with more buffers than the equivalent size of the recycle ring could ultimately lead to memory leaks if page entries in the recycle ring were overwritten. To prevent this, the check to see if the recycle ring is full is changed to check if the next entry to be written is NULL. [bwh: Combine and rebase several commits so this is complete before the following buffer-packing changes. Remove module parameter.] Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2013-02-13 10:54:41 +00:00
static void efx_fini_rx_buffer(struct efx_rx_queue *rx_queue,
struct efx_rx_buffer *rx_buf)
{
/* Release the page reference we hold for the buffer. */
if (rx_buf->page)
put_page(rx_buf->page);
/* If this is the last buffer in a page, unmap and free it. */
if (rx_buf->flags & EFX_RX_BUF_LAST_IN_PAGE) {
sfc: reuse pages to avoid DMA mapping/unmapping costs On POWER systems, DMA mapping/unmapping operations are very expensive. These changes reduce these costs by trying to reuse DMA mapped pages. After all the buffers associated with a page have been processed and passed up, the page is placed into a ring (if there is room). For each page that is required for a refill operation, a page in the ring is examined to determine if its page count has fallen to 1, ie. the kernel has released its reference to these packets. If this is the case, the page can be immediately added back into the RX descriptor ring, without having to re-map it for DMA. If the kernel is still holding a reference to this page, it is removed from the ring and unmapped for DMA. Then a new page, which can immediately be used by RX buffers in the descriptor ring, is allocated and DMA mapped. The time a page needs to spend in the recycle ring before the kernel has released its page references is based on the number of buffers that use this page. As large pages can hold more RX buffers, the RX recycle ring can be shorter. This reduces memory usage on POWER systems, while maintaining the performance gain achieved by recycling pages, following the driver change to pack more than two RX buffers into large pages. When an IOMMU is not present, the recycle ring can be small to reduce memory usage, since DMA mapping operations are inexpensive. With a small recycle ring, attempting to refill the descriptor queue with more buffers than the equivalent size of the recycle ring could ultimately lead to memory leaks if page entries in the recycle ring were overwritten. To prevent this, the check to see if the recycle ring is full is changed to check if the next entry to be written is NULL. [bwh: Combine and rebase several commits so this is complete before the following buffer-packing changes. Remove module parameter.] Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2013-02-13 10:54:41 +00:00
efx_unmap_rx_buffer(rx_queue->efx, rx_buf);
efx_free_rx_buffers(rx_queue, rx_buf, 1);
sfc: reuse pages to avoid DMA mapping/unmapping costs On POWER systems, DMA mapping/unmapping operations are very expensive. These changes reduce these costs by trying to reuse DMA mapped pages. After all the buffers associated with a page have been processed and passed up, the page is placed into a ring (if there is room). For each page that is required for a refill operation, a page in the ring is examined to determine if its page count has fallen to 1, ie. the kernel has released its reference to these packets. If this is the case, the page can be immediately added back into the RX descriptor ring, without having to re-map it for DMA. If the kernel is still holding a reference to this page, it is removed from the ring and unmapped for DMA. Then a new page, which can immediately be used by RX buffers in the descriptor ring, is allocated and DMA mapped. The time a page needs to spend in the recycle ring before the kernel has released its page references is based on the number of buffers that use this page. As large pages can hold more RX buffers, the RX recycle ring can be shorter. This reduces memory usage on POWER systems, while maintaining the performance gain achieved by recycling pages, following the driver change to pack more than two RX buffers into large pages. When an IOMMU is not present, the recycle ring can be small to reduce memory usage, since DMA mapping operations are inexpensive. With a small recycle ring, attempting to refill the descriptor queue with more buffers than the equivalent size of the recycle ring could ultimately lead to memory leaks if page entries in the recycle ring were overwritten. To prevent this, the check to see if the recycle ring is full is changed to check if the next entry to be written is NULL. [bwh: Combine and rebase several commits so this is complete before the following buffer-packing changes. Remove module parameter.] Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2013-02-13 10:54:41 +00:00
}
rx_buf->page = NULL;
}
/* Recycle the pages that are used by buffers that have just been received. */
static void efx_recycle_rx_pages(struct efx_channel *channel,
struct efx_rx_buffer *rx_buf,
unsigned int n_frags)
{
struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
do {
sfc: reuse pages to avoid DMA mapping/unmapping costs On POWER systems, DMA mapping/unmapping operations are very expensive. These changes reduce these costs by trying to reuse DMA mapped pages. After all the buffers associated with a page have been processed and passed up, the page is placed into a ring (if there is room). For each page that is required for a refill operation, a page in the ring is examined to determine if its page count has fallen to 1, ie. the kernel has released its reference to these packets. If this is the case, the page can be immediately added back into the RX descriptor ring, without having to re-map it for DMA. If the kernel is still holding a reference to this page, it is removed from the ring and unmapped for DMA. Then a new page, which can immediately be used by RX buffers in the descriptor ring, is allocated and DMA mapped. The time a page needs to spend in the recycle ring before the kernel has released its page references is based on the number of buffers that use this page. As large pages can hold more RX buffers, the RX recycle ring can be shorter. This reduces memory usage on POWER systems, while maintaining the performance gain achieved by recycling pages, following the driver change to pack more than two RX buffers into large pages. When an IOMMU is not present, the recycle ring can be small to reduce memory usage, since DMA mapping operations are inexpensive. With a small recycle ring, attempting to refill the descriptor queue with more buffers than the equivalent size of the recycle ring could ultimately lead to memory leaks if page entries in the recycle ring were overwritten. To prevent this, the check to see if the recycle ring is full is changed to check if the next entry to be written is NULL. [bwh: Combine and rebase several commits so this is complete before the following buffer-packing changes. Remove module parameter.] Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2013-02-13 10:54:41 +00:00
efx_recycle_rx_page(channel, rx_buf);
rx_buf = efx_rx_buf_next(rx_queue, rx_buf);
} while (--n_frags);
}
static void efx_discard_rx_packet(struct efx_channel *channel,
struct efx_rx_buffer *rx_buf,
unsigned int n_frags)
{
struct efx_rx_queue *rx_queue = efx_channel_get_rx_queue(channel);
efx_recycle_rx_pages(channel, rx_buf, n_frags);
efx_free_rx_buffers(rx_queue, rx_buf, n_frags);
}
/**
* efx_fast_push_rx_descriptors - push new RX descriptors quickly
* @rx_queue: RX descriptor queue
*
* This will aim to fill the RX descriptor queue up to
* @rx_queue->@max_fill. If there is insufficient atomic
* memory to do so, a slow fill will be scheduled.
*
* The caller must provide serialisation (none is used here). In practise,
* this means this function must run from the NAPI handler, or be called
* when NAPI is disabled.
*/
void efx_fast_push_rx_descriptors(struct efx_rx_queue *rx_queue, bool atomic)
{
struct efx_nic *efx = rx_queue->efx;
unsigned int fill_level, batch_size;
int space, rc = 0;
if (!rx_queue->refill_enabled)
return;
/* Calculate current fill level, and exit if we don't need to fill */
fill_level = (rx_queue->added_count - rx_queue->removed_count);
EFX_WARN_ON_ONCE_PARANOID(fill_level > rx_queue->efx->rxq_entries);
if (fill_level >= rx_queue->fast_fill_trigger)
goto out;
/* Record minimum fill level */
if (unlikely(fill_level < rx_queue->min_fill)) {
if (fill_level)
rx_queue->min_fill = fill_level;
}
batch_size = efx->rx_pages_per_batch * efx->rx_bufs_per_page;
space = rx_queue->max_fill - fill_level;
EFX_WARN_ON_ONCE_PARANOID(space < batch_size);
netif_vdbg(rx_queue->efx, rx_status, rx_queue->efx->net_dev,
"RX queue %d fast-filling descriptor ring from"
" level %d to level %d\n",
efx_rx_queue_index(rx_queue), fill_level,
rx_queue->max_fill);
do {
rc = efx_init_rx_buffers(rx_queue, atomic);
if (unlikely(rc)) {
/* Ensure that we don't leave the rx queue empty */
efx_schedule_slow_fill(rx_queue);
goto out;
}
} while ((space -= batch_size) >= batch_size);
netif_vdbg(rx_queue->efx, rx_status, rx_queue->efx->net_dev,
"RX queue %d fast-filled descriptor ring "
"to level %d\n", efx_rx_queue_index(rx_queue),
rx_queue->added_count - rx_queue->removed_count);
out:
if (rx_queue->notified_count != rx_queue->added_count)
efx_nic_notify_rx_desc(rx_queue);
}
void efx_rx_slow_fill(struct timer_list *t)
{
struct efx_rx_queue *rx_queue = from_timer(rx_queue, t, slow_fill);
/* Post an event to cause NAPI to run and refill the queue */
efx_nic_generate_fill_event(rx_queue);
++rx_queue->slow_fill_count;
}
static void efx_rx_packet__check_len(struct efx_rx_queue *rx_queue,
struct efx_rx_buffer *rx_buf,
int len)
{
struct efx_nic *efx = rx_queue->efx;
unsigned max_len = rx_buf->len - efx->type->rx_buffer_padding;
if (likely(len <= max_len))
return;
/* The packet must be discarded, but this is only a fatal error
* if the caller indicated it was
*/
rx_buf->flags |= EFX_RX_PKT_DISCARD;
if (net_ratelimit())
netif_err(efx, rx_err, efx->net_dev,
"RX queue %d overlength RX event (%#x > %#x)\n",
efx_rx_queue_index(rx_queue), len, max_len);
efx_rx_queue_channel(rx_queue)->n_rx_overlength++;
}
/* Pass a received packet up through GRO. GRO can handle pages
* regardless of checksum state and skbs with a good checksum.
*/
static void
efx_rx_packet_gro(struct efx_channel *channel, struct efx_rx_buffer *rx_buf,
unsigned int n_frags, u8 *eh)
{
struct napi_struct *napi = &channel->napi_str;
struct efx_nic *efx = channel->efx;
struct sk_buff *skb;
skb = napi_get_frags(napi);
if (unlikely(!skb)) {
struct efx_rx_queue *rx_queue;
rx_queue = efx_channel_get_rx_queue(channel);
efx_free_rx_buffers(rx_queue, rx_buf, n_frags);
return;
}
if (efx->net_dev->features & NETIF_F_RXHASH)
skb_set_hash(skb, efx_rx_buf_hash(efx, eh),
PKT_HASH_TYPE_L3);
skb->ip_summed = ((rx_buf->flags & EFX_RX_PKT_CSUMMED) ?
CHECKSUM_UNNECESSARY : CHECKSUM_NONE);
skb->csum_level = !!(rx_buf->flags & EFX_RX_PKT_CSUM_LEVEL);
for (;;) {
skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags,
rx_buf->page, rx_buf->page_offset,
rx_buf->len);
rx_buf->page = NULL;
skb->len += rx_buf->len;
if (skb_shinfo(skb)->nr_frags == n_frags)
break;
rx_buf = efx_rx_buf_next(&channel->rx_queue, rx_buf);
}
skb->data_len = skb->len;
skb->truesize += n_frags * efx->rx_buffer_truesize;
skb_record_rx_queue(skb, channel->rx_queue.core_index);
napi_gro_frags(napi);
}
/* Allocate and construct an SKB around page fragments */
static struct sk_buff *efx_rx_mk_skb(struct efx_channel *channel,
struct efx_rx_buffer *rx_buf,
unsigned int n_frags,
u8 *eh, int hdr_len)
{
struct efx_nic *efx = channel->efx;
struct sk_buff *skb;
/* Allocate an SKB to store the headers */
skb = netdev_alloc_skb(efx->net_dev,
efx->rx_ip_align + efx->rx_prefix_size +
hdr_len);
if (unlikely(skb == NULL)) {
atomic_inc(&efx->n_rx_noskb_drops);
return NULL;
}
EFX_WARN_ON_ONCE_PARANOID(rx_buf->len < hdr_len);
memcpy(skb->data + efx->rx_ip_align, eh - efx->rx_prefix_size,
efx->rx_prefix_size + hdr_len);
skb_reserve(skb, efx->rx_ip_align + efx->rx_prefix_size);
__skb_put(skb, hdr_len);
/* Append the remaining page(s) onto the frag list */
if (rx_buf->len > hdr_len) {
rx_buf->page_offset += hdr_len;
rx_buf->len -= hdr_len;
for (;;) {
skb_fill_page_desc(skb, skb_shinfo(skb)->nr_frags,
rx_buf->page, rx_buf->page_offset,
rx_buf->len);
rx_buf->page = NULL;
skb->len += rx_buf->len;
skb->data_len += rx_buf->len;
if (skb_shinfo(skb)->nr_frags == n_frags)
break;
rx_buf = efx_rx_buf_next(&channel->rx_queue, rx_buf);
}
} else {
__free_pages(rx_buf->page, efx->rx_buffer_order);
rx_buf->page = NULL;
n_frags = 0;
}
skb->truesize += n_frags * efx->rx_buffer_truesize;
/* Move past the ethernet header */
skb->protocol = eth_type_trans(skb, efx->net_dev);
skb_mark_napi_id(skb, &channel->napi_str);
return skb;
}
void efx_rx_packet(struct efx_rx_queue *rx_queue, unsigned int index,
unsigned int n_frags, unsigned int len, u16 flags)
{
struct efx_nic *efx = rx_queue->efx;
struct efx_channel *channel = efx_rx_queue_channel(rx_queue);
struct efx_rx_buffer *rx_buf;
rx_queue->rx_packets++;
rx_buf = efx_rx_buffer(rx_queue, index);
rx_buf->flags |= flags;
/* Validate the number of fragments and completed length */
if (n_frags == 1) {
if (!(flags & EFX_RX_PKT_PREFIX_LEN))
efx_rx_packet__check_len(rx_queue, rx_buf, len);
} else if (unlikely(n_frags > EFX_RX_MAX_FRAGS) ||
unlikely(len <= (n_frags - 1) * efx->rx_dma_len) ||
unlikely(len > n_frags * efx->rx_dma_len) ||
unlikely(!efx->rx_scatter)) {
/* If this isn't an explicit discard request, either
* the hardware or the driver is broken.
*/
WARN_ON(!(len == 0 && rx_buf->flags & EFX_RX_PKT_DISCARD));
rx_buf->flags |= EFX_RX_PKT_DISCARD;
}
netif_vdbg(efx, rx_status, efx->net_dev,
"RX queue %d received ids %x-%x len %d %s%s\n",
efx_rx_queue_index(rx_queue), index,
(index + n_frags - 1) & rx_queue->ptr_mask, len,
(rx_buf->flags & EFX_RX_PKT_CSUMMED) ? " [SUMMED]" : "",
(rx_buf->flags & EFX_RX_PKT_DISCARD) ? " [DISCARD]" : "");
/* Discard packet, if instructed to do so. Process the
* previous receive first.
*/
if (unlikely(rx_buf->flags & EFX_RX_PKT_DISCARD)) {
efx_rx_flush_packet(channel);
efx_discard_rx_packet(channel, rx_buf, n_frags);
return;
}
if (n_frags == 1 && !(flags & EFX_RX_PKT_PREFIX_LEN))
rx_buf->len = len;
sfc: reuse pages to avoid DMA mapping/unmapping costs On POWER systems, DMA mapping/unmapping operations are very expensive. These changes reduce these costs by trying to reuse DMA mapped pages. After all the buffers associated with a page have been processed and passed up, the page is placed into a ring (if there is room). For each page that is required for a refill operation, a page in the ring is examined to determine if its page count has fallen to 1, ie. the kernel has released its reference to these packets. If this is the case, the page can be immediately added back into the RX descriptor ring, without having to re-map it for DMA. If the kernel is still holding a reference to this page, it is removed from the ring and unmapped for DMA. Then a new page, which can immediately be used by RX buffers in the descriptor ring, is allocated and DMA mapped. The time a page needs to spend in the recycle ring before the kernel has released its page references is based on the number of buffers that use this page. As large pages can hold more RX buffers, the RX recycle ring can be shorter. This reduces memory usage on POWER systems, while maintaining the performance gain achieved by recycling pages, following the driver change to pack more than two RX buffers into large pages. When an IOMMU is not present, the recycle ring can be small to reduce memory usage, since DMA mapping operations are inexpensive. With a small recycle ring, attempting to refill the descriptor queue with more buffers than the equivalent size of the recycle ring could ultimately lead to memory leaks if page entries in the recycle ring were overwritten. To prevent this, the check to see if the recycle ring is full is changed to check if the next entry to be written is NULL. [bwh: Combine and rebase several commits so this is complete before the following buffer-packing changes. Remove module parameter.] Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2013-02-13 10:54:41 +00:00
/* Release and/or sync the DMA mapping - assumes all RX buffers
* consumed in-order per RX queue.
*/
sfc: reuse pages to avoid DMA mapping/unmapping costs On POWER systems, DMA mapping/unmapping operations are very expensive. These changes reduce these costs by trying to reuse DMA mapped pages. After all the buffers associated with a page have been processed and passed up, the page is placed into a ring (if there is room). For each page that is required for a refill operation, a page in the ring is examined to determine if its page count has fallen to 1, ie. the kernel has released its reference to these packets. If this is the case, the page can be immediately added back into the RX descriptor ring, without having to re-map it for DMA. If the kernel is still holding a reference to this page, it is removed from the ring and unmapped for DMA. Then a new page, which can immediately be used by RX buffers in the descriptor ring, is allocated and DMA mapped. The time a page needs to spend in the recycle ring before the kernel has released its page references is based on the number of buffers that use this page. As large pages can hold more RX buffers, the RX recycle ring can be shorter. This reduces memory usage on POWER systems, while maintaining the performance gain achieved by recycling pages, following the driver change to pack more than two RX buffers into large pages. When an IOMMU is not present, the recycle ring can be small to reduce memory usage, since DMA mapping operations are inexpensive. With a small recycle ring, attempting to refill the descriptor queue with more buffers than the equivalent size of the recycle ring could ultimately lead to memory leaks if page entries in the recycle ring were overwritten. To prevent this, the check to see if the recycle ring is full is changed to check if the next entry to be written is NULL. [bwh: Combine and rebase several commits so this is complete before the following buffer-packing changes. Remove module parameter.] Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2013-02-13 10:54:41 +00:00
efx_sync_rx_buffer(efx, rx_buf, rx_buf->len);
/* Prefetch nice and early so data will (hopefully) be in cache by
* the time we look at it.
*/
prefetch(efx_rx_buf_va(rx_buf));
rx_buf->page_offset += efx->rx_prefix_size;
rx_buf->len -= efx->rx_prefix_size;
if (n_frags > 1) {
/* Release/sync DMA mapping for additional fragments.
* Fix length for last fragment.
*/
unsigned int tail_frags = n_frags - 1;
for (;;) {
rx_buf = efx_rx_buf_next(rx_queue, rx_buf);
if (--tail_frags == 0)
break;
efx_sync_rx_buffer(efx, rx_buf, efx->rx_dma_len);
}
rx_buf->len = len - (n_frags - 1) * efx->rx_dma_len;
sfc: reuse pages to avoid DMA mapping/unmapping costs On POWER systems, DMA mapping/unmapping operations are very expensive. These changes reduce these costs by trying to reuse DMA mapped pages. After all the buffers associated with a page have been processed and passed up, the page is placed into a ring (if there is room). For each page that is required for a refill operation, a page in the ring is examined to determine if its page count has fallen to 1, ie. the kernel has released its reference to these packets. If this is the case, the page can be immediately added back into the RX descriptor ring, without having to re-map it for DMA. If the kernel is still holding a reference to this page, it is removed from the ring and unmapped for DMA. Then a new page, which can immediately be used by RX buffers in the descriptor ring, is allocated and DMA mapped. The time a page needs to spend in the recycle ring before the kernel has released its page references is based on the number of buffers that use this page. As large pages can hold more RX buffers, the RX recycle ring can be shorter. This reduces memory usage on POWER systems, while maintaining the performance gain achieved by recycling pages, following the driver change to pack more than two RX buffers into large pages. When an IOMMU is not present, the recycle ring can be small to reduce memory usage, since DMA mapping operations are inexpensive. With a small recycle ring, attempting to refill the descriptor queue with more buffers than the equivalent size of the recycle ring could ultimately lead to memory leaks if page entries in the recycle ring were overwritten. To prevent this, the check to see if the recycle ring is full is changed to check if the next entry to be written is NULL. [bwh: Combine and rebase several commits so this is complete before the following buffer-packing changes. Remove module parameter.] Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2013-02-13 10:54:41 +00:00
efx_sync_rx_buffer(efx, rx_buf, rx_buf->len);
}
/* All fragments have been DMA-synced, so recycle pages. */
sfc: reuse pages to avoid DMA mapping/unmapping costs On POWER systems, DMA mapping/unmapping operations are very expensive. These changes reduce these costs by trying to reuse DMA mapped pages. After all the buffers associated with a page have been processed and passed up, the page is placed into a ring (if there is room). For each page that is required for a refill operation, a page in the ring is examined to determine if its page count has fallen to 1, ie. the kernel has released its reference to these packets. If this is the case, the page can be immediately added back into the RX descriptor ring, without having to re-map it for DMA. If the kernel is still holding a reference to this page, it is removed from the ring and unmapped for DMA. Then a new page, which can immediately be used by RX buffers in the descriptor ring, is allocated and DMA mapped. The time a page needs to spend in the recycle ring before the kernel has released its page references is based on the number of buffers that use this page. As large pages can hold more RX buffers, the RX recycle ring can be shorter. This reduces memory usage on POWER systems, while maintaining the performance gain achieved by recycling pages, following the driver change to pack more than two RX buffers into large pages. When an IOMMU is not present, the recycle ring can be small to reduce memory usage, since DMA mapping operations are inexpensive. With a small recycle ring, attempting to refill the descriptor queue with more buffers than the equivalent size of the recycle ring could ultimately lead to memory leaks if page entries in the recycle ring were overwritten. To prevent this, the check to see if the recycle ring is full is changed to check if the next entry to be written is NULL. [bwh: Combine and rebase several commits so this is complete before the following buffer-packing changes. Remove module parameter.] Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2013-02-13 10:54:41 +00:00
rx_buf = efx_rx_buffer(rx_queue, index);
efx_recycle_rx_pages(channel, rx_buf, n_frags);
sfc: reuse pages to avoid DMA mapping/unmapping costs On POWER systems, DMA mapping/unmapping operations are very expensive. These changes reduce these costs by trying to reuse DMA mapped pages. After all the buffers associated with a page have been processed and passed up, the page is placed into a ring (if there is room). For each page that is required for a refill operation, a page in the ring is examined to determine if its page count has fallen to 1, ie. the kernel has released its reference to these packets. If this is the case, the page can be immediately added back into the RX descriptor ring, without having to re-map it for DMA. If the kernel is still holding a reference to this page, it is removed from the ring and unmapped for DMA. Then a new page, which can immediately be used by RX buffers in the descriptor ring, is allocated and DMA mapped. The time a page needs to spend in the recycle ring before the kernel has released its page references is based on the number of buffers that use this page. As large pages can hold more RX buffers, the RX recycle ring can be shorter. This reduces memory usage on POWER systems, while maintaining the performance gain achieved by recycling pages, following the driver change to pack more than two RX buffers into large pages. When an IOMMU is not present, the recycle ring can be small to reduce memory usage, since DMA mapping operations are inexpensive. With a small recycle ring, attempting to refill the descriptor queue with more buffers than the equivalent size of the recycle ring could ultimately lead to memory leaks if page entries in the recycle ring were overwritten. To prevent this, the check to see if the recycle ring is full is changed to check if the next entry to be written is NULL. [bwh: Combine and rebase several commits so this is complete before the following buffer-packing changes. Remove module parameter.] Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2013-02-13 10:54:41 +00:00
/* Pipeline receives so that we give time for packet headers to be
* prefetched into cache.
*/
efx_rx_flush_packet(channel);
channel->rx_pkt_n_frags = n_frags;
channel->rx_pkt_index = index;
}
static void efx_rx_deliver(struct efx_channel *channel, u8 *eh,
struct efx_rx_buffer *rx_buf,
unsigned int n_frags)
{
struct sk_buff *skb;
u16 hdr_len = min_t(u16, rx_buf->len, EFX_SKB_HEADERS);
skb = efx_rx_mk_skb(channel, rx_buf, n_frags, eh, hdr_len);
if (unlikely(skb == NULL)) {
struct efx_rx_queue *rx_queue;
rx_queue = efx_channel_get_rx_queue(channel);
efx_free_rx_buffers(rx_queue, rx_buf, n_frags);
return;
}
skb_record_rx_queue(skb, channel->rx_queue.core_index);
/* Set the SKB flags */
skb_checksum_none_assert(skb);
if (likely(rx_buf->flags & EFX_RX_PKT_CSUMMED)) {
skb->ip_summed = CHECKSUM_UNNECESSARY;
skb->csum_level = !!(rx_buf->flags & EFX_RX_PKT_CSUM_LEVEL);
}
efx_rx_skb_attach_timestamp(channel, skb);
if (channel->type->receive_skb)
if (channel->type->receive_skb(channel, skb))
return;
/* Pass the packet up */
if (channel->rx_list != NULL)
/* Add to list, will pass up later */
list_add_tail(&skb->list, channel->rx_list);
else
/* No list, so pass it up now */
netif_receive_skb(skb);
}
/** efx_do_xdp: perform XDP processing on a received packet
*
* Returns true if packet should still be delivered.
*/
static bool efx_do_xdp(struct efx_nic *efx, struct efx_channel *channel,
struct efx_rx_buffer *rx_buf, u8 **ehp)
{
u8 rx_prefix[EFX_MAX_RX_PREFIX_SIZE];
struct efx_rx_queue *rx_queue;
struct bpf_prog *xdp_prog;
struct xdp_frame *xdpf;
struct xdp_buff xdp;
u32 xdp_act;
s16 offset;
int err;
rcu_read_lock();
xdp_prog = rcu_dereference(efx->xdp_prog);
if (!xdp_prog) {
rcu_read_unlock();
return true;
}
rx_queue = efx_channel_get_rx_queue(channel);
if (unlikely(channel->rx_pkt_n_frags > 1)) {
/* We can't do XDP on fragmented packets - drop. */
rcu_read_unlock();
efx_free_rx_buffers(rx_queue, rx_buf,
channel->rx_pkt_n_frags);
if (net_ratelimit())
netif_err(efx, rx_err, efx->net_dev,
"XDP is not possible with multiple receive fragments (%d)\n",
channel->rx_pkt_n_frags);
channel->n_rx_xdp_bad_drops++;
return false;
}
dma_sync_single_for_cpu(&efx->pci_dev->dev, rx_buf->dma_addr,
rx_buf->len, DMA_FROM_DEVICE);
/* Save the rx prefix. */
EFX_WARN_ON_PARANOID(efx->rx_prefix_size > EFX_MAX_RX_PREFIX_SIZE);
memcpy(rx_prefix, *ehp - efx->rx_prefix_size,
efx->rx_prefix_size);
xdp.data = *ehp;
xdp.data_hard_start = xdp.data - XDP_PACKET_HEADROOM;
/* No support yet for XDP metadata */
xdp_set_data_meta_invalid(&xdp);
xdp.data_end = xdp.data + rx_buf->len;
xdp.rxq = &rx_queue->xdp_rxq_info;
xdp_act = bpf_prog_run_xdp(xdp_prog, &xdp);
rcu_read_unlock();
offset = (u8 *)xdp.data - *ehp;
switch (xdp_act) {
case XDP_PASS:
/* Fix up rx prefix. */
if (offset) {
*ehp += offset;
rx_buf->page_offset += offset;
rx_buf->len -= offset;
memcpy(*ehp - efx->rx_prefix_size, rx_prefix,
efx->rx_prefix_size);
}
break;
case XDP_TX:
/* Buffer ownership passes to tx on success. */
xdpf = convert_to_xdp_frame(&xdp);
err = efx_xdp_tx_buffers(efx, 1, &xdpf, true);
if (unlikely(err != 1)) {
efx_free_rx_buffers(rx_queue, rx_buf, 1);
if (net_ratelimit())
netif_err(efx, rx_err, efx->net_dev,
"XDP TX failed (%d)\n", err);
channel->n_rx_xdp_bad_drops++;
trace_xdp_exception(efx->net_dev, xdp_prog, xdp_act);
} else {
channel->n_rx_xdp_tx++;
}
break;
case XDP_REDIRECT:
err = xdp_do_redirect(efx->net_dev, &xdp, xdp_prog);
if (unlikely(err)) {
efx_free_rx_buffers(rx_queue, rx_buf, 1);
if (net_ratelimit())
netif_err(efx, rx_err, efx->net_dev,
"XDP redirect failed (%d)\n", err);
channel->n_rx_xdp_bad_drops++;
trace_xdp_exception(efx->net_dev, xdp_prog, xdp_act);
} else {
channel->n_rx_xdp_redirect++;
}
break;
default:
bpf_warn_invalid_xdp_action(xdp_act);
efx_free_rx_buffers(rx_queue, rx_buf, 1);
channel->n_rx_xdp_bad_drops++;
trace_xdp_exception(efx->net_dev, xdp_prog, xdp_act);
break;
case XDP_ABORTED:
trace_xdp_exception(efx->net_dev, xdp_prog, xdp_act);
/* Fall through */
case XDP_DROP:
efx_free_rx_buffers(rx_queue, rx_buf, 1);
channel->n_rx_xdp_drops++;
break;
}
return xdp_act == XDP_PASS;
}
/* Handle a received packet. Second half: Touches packet payload. */
void __efx_rx_packet(struct efx_channel *channel)
{
struct efx_nic *efx = channel->efx;
struct efx_rx_buffer *rx_buf =
efx_rx_buffer(&channel->rx_queue, channel->rx_pkt_index);
u8 *eh = efx_rx_buf_va(rx_buf);
/* Read length from the prefix if necessary. This already
* excludes the length of the prefix itself.
*/
if (rx_buf->flags & EFX_RX_PKT_PREFIX_LEN)
rx_buf->len = le16_to_cpup((__le16 *)
(eh + efx->rx_packet_len_offset));
/* If we're in loopback test, then pass the packet directly to the
* loopback layer, and free the rx_buf here
*/
if (unlikely(efx->loopback_selftest)) {
struct efx_rx_queue *rx_queue;
efx_loopback_rx_packet(efx, eh, rx_buf->len);
rx_queue = efx_channel_get_rx_queue(channel);
efx_free_rx_buffers(rx_queue, rx_buf,
channel->rx_pkt_n_frags);
goto out;
}
if (!efx_do_xdp(efx, channel, rx_buf, &eh))
goto out;
if (unlikely(!(efx->net_dev->features & NETIF_F_RXCSUM)))
rx_buf->flags &= ~EFX_RX_PKT_CSUMMED;
if ((rx_buf->flags & EFX_RX_PKT_TCP) && !channel->type->receive_skb)
efx_rx_packet_gro(channel, rx_buf, channel->rx_pkt_n_frags, eh);
else
efx_rx_deliver(channel, eh, rx_buf, channel->rx_pkt_n_frags);
out:
channel->rx_pkt_n_frags = 0;
}
int efx_probe_rx_queue(struct efx_rx_queue *rx_queue)
{
struct efx_nic *efx = rx_queue->efx;
unsigned int entries;
int rc;
/* Create the smallest power-of-two aligned ring */
entries = max(roundup_pow_of_two(efx->rxq_entries), EFX_MIN_DMAQ_SIZE);
EFX_WARN_ON_PARANOID(entries > EFX_MAX_DMAQ_SIZE);
rx_queue->ptr_mask = entries - 1;
netif_dbg(efx, probe, efx->net_dev,
"creating RX queue %d size %#x mask %#x\n",
efx_rx_queue_index(rx_queue), efx->rxq_entries,
rx_queue->ptr_mask);
/* Allocate RX buffers */
rx_queue->buffer = kcalloc(entries, sizeof(*rx_queue->buffer),
GFP_KERNEL);
if (!rx_queue->buffer)
return -ENOMEM;
rc = efx_nic_probe_rx(rx_queue);
if (rc) {
kfree(rx_queue->buffer);
rx_queue->buffer = NULL;
}
sfc: reuse pages to avoid DMA mapping/unmapping costs On POWER systems, DMA mapping/unmapping operations are very expensive. These changes reduce these costs by trying to reuse DMA mapped pages. After all the buffers associated with a page have been processed and passed up, the page is placed into a ring (if there is room). For each page that is required for a refill operation, a page in the ring is examined to determine if its page count has fallen to 1, ie. the kernel has released its reference to these packets. If this is the case, the page can be immediately added back into the RX descriptor ring, without having to re-map it for DMA. If the kernel is still holding a reference to this page, it is removed from the ring and unmapped for DMA. Then a new page, which can immediately be used by RX buffers in the descriptor ring, is allocated and DMA mapped. The time a page needs to spend in the recycle ring before the kernel has released its page references is based on the number of buffers that use this page. As large pages can hold more RX buffers, the RX recycle ring can be shorter. This reduces memory usage on POWER systems, while maintaining the performance gain achieved by recycling pages, following the driver change to pack more than two RX buffers into large pages. When an IOMMU is not present, the recycle ring can be small to reduce memory usage, since DMA mapping operations are inexpensive. With a small recycle ring, attempting to refill the descriptor queue with more buffers than the equivalent size of the recycle ring could ultimately lead to memory leaks if page entries in the recycle ring were overwritten. To prevent this, the check to see if the recycle ring is full is changed to check if the next entry to be written is NULL. [bwh: Combine and rebase several commits so this is complete before the following buffer-packing changes. Remove module parameter.] Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2013-02-13 10:54:41 +00:00
return rc;
}
static void efx_init_rx_recycle_ring(struct efx_nic *efx,
struct efx_rx_queue *rx_queue)
sfc: reuse pages to avoid DMA mapping/unmapping costs On POWER systems, DMA mapping/unmapping operations are very expensive. These changes reduce these costs by trying to reuse DMA mapped pages. After all the buffers associated with a page have been processed and passed up, the page is placed into a ring (if there is room). For each page that is required for a refill operation, a page in the ring is examined to determine if its page count has fallen to 1, ie. the kernel has released its reference to these packets. If this is the case, the page can be immediately added back into the RX descriptor ring, without having to re-map it for DMA. If the kernel is still holding a reference to this page, it is removed from the ring and unmapped for DMA. Then a new page, which can immediately be used by RX buffers in the descriptor ring, is allocated and DMA mapped. The time a page needs to spend in the recycle ring before the kernel has released its page references is based on the number of buffers that use this page. As large pages can hold more RX buffers, the RX recycle ring can be shorter. This reduces memory usage on POWER systems, while maintaining the performance gain achieved by recycling pages, following the driver change to pack more than two RX buffers into large pages. When an IOMMU is not present, the recycle ring can be small to reduce memory usage, since DMA mapping operations are inexpensive. With a small recycle ring, attempting to refill the descriptor queue with more buffers than the equivalent size of the recycle ring could ultimately lead to memory leaks if page entries in the recycle ring were overwritten. To prevent this, the check to see if the recycle ring is full is changed to check if the next entry to be written is NULL. [bwh: Combine and rebase several commits so this is complete before the following buffer-packing changes. Remove module parameter.] Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2013-02-13 10:54:41 +00:00
{
unsigned int bufs_in_recycle_ring, page_ring_size;
/* Set the RX recycle ring size */
#ifdef CONFIG_PPC64
bufs_in_recycle_ring = EFX_RECYCLE_RING_SIZE_IOMMU;
#else
if (iommu_present(&pci_bus_type))
sfc: reuse pages to avoid DMA mapping/unmapping costs On POWER systems, DMA mapping/unmapping operations are very expensive. These changes reduce these costs by trying to reuse DMA mapped pages. After all the buffers associated with a page have been processed and passed up, the page is placed into a ring (if there is room). For each page that is required for a refill operation, a page in the ring is examined to determine if its page count has fallen to 1, ie. the kernel has released its reference to these packets. If this is the case, the page can be immediately added back into the RX descriptor ring, without having to re-map it for DMA. If the kernel is still holding a reference to this page, it is removed from the ring and unmapped for DMA. Then a new page, which can immediately be used by RX buffers in the descriptor ring, is allocated and DMA mapped. The time a page needs to spend in the recycle ring before the kernel has released its page references is based on the number of buffers that use this page. As large pages can hold more RX buffers, the RX recycle ring can be shorter. This reduces memory usage on POWER systems, while maintaining the performance gain achieved by recycling pages, following the driver change to pack more than two RX buffers into large pages. When an IOMMU is not present, the recycle ring can be small to reduce memory usage, since DMA mapping operations are inexpensive. With a small recycle ring, attempting to refill the descriptor queue with more buffers than the equivalent size of the recycle ring could ultimately lead to memory leaks if page entries in the recycle ring were overwritten. To prevent this, the check to see if the recycle ring is full is changed to check if the next entry to be written is NULL. [bwh: Combine and rebase several commits so this is complete before the following buffer-packing changes. Remove module parameter.] Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2013-02-13 10:54:41 +00:00
bufs_in_recycle_ring = EFX_RECYCLE_RING_SIZE_IOMMU;
else
bufs_in_recycle_ring = EFX_RECYCLE_RING_SIZE_NOIOMMU;
#endif /* CONFIG_PPC64 */
page_ring_size = roundup_pow_of_two(bufs_in_recycle_ring /
efx->rx_bufs_per_page);
rx_queue->page_ring = kcalloc(page_ring_size,
sizeof(*rx_queue->page_ring), GFP_KERNEL);
rx_queue->page_ptr_mask = page_ring_size - 1;
}
void efx_init_rx_queue(struct efx_rx_queue *rx_queue)
{
struct efx_nic *efx = rx_queue->efx;
unsigned int max_fill, trigger, max_trigger;
int rc = 0;
netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
"initialising RX queue %d\n", efx_rx_queue_index(rx_queue));
/* Initialise ptr fields */
rx_queue->added_count = 0;
rx_queue->notified_count = 0;
rx_queue->removed_count = 0;
rx_queue->min_fill = -1U;
sfc: reuse pages to avoid DMA mapping/unmapping costs On POWER systems, DMA mapping/unmapping operations are very expensive. These changes reduce these costs by trying to reuse DMA mapped pages. After all the buffers associated with a page have been processed and passed up, the page is placed into a ring (if there is room). For each page that is required for a refill operation, a page in the ring is examined to determine if its page count has fallen to 1, ie. the kernel has released its reference to these packets. If this is the case, the page can be immediately added back into the RX descriptor ring, without having to re-map it for DMA. If the kernel is still holding a reference to this page, it is removed from the ring and unmapped for DMA. Then a new page, which can immediately be used by RX buffers in the descriptor ring, is allocated and DMA mapped. The time a page needs to spend in the recycle ring before the kernel has released its page references is based on the number of buffers that use this page. As large pages can hold more RX buffers, the RX recycle ring can be shorter. This reduces memory usage on POWER systems, while maintaining the performance gain achieved by recycling pages, following the driver change to pack more than two RX buffers into large pages. When an IOMMU is not present, the recycle ring can be small to reduce memory usage, since DMA mapping operations are inexpensive. With a small recycle ring, attempting to refill the descriptor queue with more buffers than the equivalent size of the recycle ring could ultimately lead to memory leaks if page entries in the recycle ring were overwritten. To prevent this, the check to see if the recycle ring is full is changed to check if the next entry to be written is NULL. [bwh: Combine and rebase several commits so this is complete before the following buffer-packing changes. Remove module parameter.] Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2013-02-13 10:54:41 +00:00
efx_init_rx_recycle_ring(efx, rx_queue);
rx_queue->page_remove = 0;
rx_queue->page_add = rx_queue->page_ptr_mask + 1;
rx_queue->page_recycle_count = 0;
rx_queue->page_recycle_failed = 0;
rx_queue->page_recycle_full = 0;
/* Initialise limit fields */
max_fill = efx->rxq_entries - EFX_RXD_HEAD_ROOM;
max_trigger =
max_fill - efx->rx_pages_per_batch * efx->rx_bufs_per_page;
if (rx_refill_threshold != 0) {
trigger = max_fill * min(rx_refill_threshold, 100U) / 100U;
if (trigger > max_trigger)
trigger = max_trigger;
} else {
trigger = max_trigger;
}
rx_queue->max_fill = max_fill;
rx_queue->fast_fill_trigger = trigger;
rx_queue->refill_enabled = true;
/* Initialise XDP queue information */
rc = xdp_rxq_info_reg(&rx_queue->xdp_rxq_info, efx->net_dev,
rx_queue->core_index);
if (rc) {
netif_err(efx, rx_err, efx->net_dev,
"Failure to initialise XDP queue information rc=%d\n",
rc);
efx->xdp_rxq_info_failed = true;
} else {
rx_queue->xdp_rxq_info_valid = true;
}
/* Set up RX descriptor ring */
efx_nic_init_rx(rx_queue);
}
void efx_fini_rx_queue(struct efx_rx_queue *rx_queue)
{
int i;
sfc: reuse pages to avoid DMA mapping/unmapping costs On POWER systems, DMA mapping/unmapping operations are very expensive. These changes reduce these costs by trying to reuse DMA mapped pages. After all the buffers associated with a page have been processed and passed up, the page is placed into a ring (if there is room). For each page that is required for a refill operation, a page in the ring is examined to determine if its page count has fallen to 1, ie. the kernel has released its reference to these packets. If this is the case, the page can be immediately added back into the RX descriptor ring, without having to re-map it for DMA. If the kernel is still holding a reference to this page, it is removed from the ring and unmapped for DMA. Then a new page, which can immediately be used by RX buffers in the descriptor ring, is allocated and DMA mapped. The time a page needs to spend in the recycle ring before the kernel has released its page references is based on the number of buffers that use this page. As large pages can hold more RX buffers, the RX recycle ring can be shorter. This reduces memory usage on POWER systems, while maintaining the performance gain achieved by recycling pages, following the driver change to pack more than two RX buffers into large pages. When an IOMMU is not present, the recycle ring can be small to reduce memory usage, since DMA mapping operations are inexpensive. With a small recycle ring, attempting to refill the descriptor queue with more buffers than the equivalent size of the recycle ring could ultimately lead to memory leaks if page entries in the recycle ring were overwritten. To prevent this, the check to see if the recycle ring is full is changed to check if the next entry to be written is NULL. [bwh: Combine and rebase several commits so this is complete before the following buffer-packing changes. Remove module parameter.] Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2013-02-13 10:54:41 +00:00
struct efx_nic *efx = rx_queue->efx;
struct efx_rx_buffer *rx_buf;
netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
"shutting down RX queue %d\n", efx_rx_queue_index(rx_queue));
del_timer_sync(&rx_queue->slow_fill);
sfc: reuse pages to avoid DMA mapping/unmapping costs On POWER systems, DMA mapping/unmapping operations are very expensive. These changes reduce these costs by trying to reuse DMA mapped pages. After all the buffers associated with a page have been processed and passed up, the page is placed into a ring (if there is room). For each page that is required for a refill operation, a page in the ring is examined to determine if its page count has fallen to 1, ie. the kernel has released its reference to these packets. If this is the case, the page can be immediately added back into the RX descriptor ring, without having to re-map it for DMA. If the kernel is still holding a reference to this page, it is removed from the ring and unmapped for DMA. Then a new page, which can immediately be used by RX buffers in the descriptor ring, is allocated and DMA mapped. The time a page needs to spend in the recycle ring before the kernel has released its page references is based on the number of buffers that use this page. As large pages can hold more RX buffers, the RX recycle ring can be shorter. This reduces memory usage on POWER systems, while maintaining the performance gain achieved by recycling pages, following the driver change to pack more than two RX buffers into large pages. When an IOMMU is not present, the recycle ring can be small to reduce memory usage, since DMA mapping operations are inexpensive. With a small recycle ring, attempting to refill the descriptor queue with more buffers than the equivalent size of the recycle ring could ultimately lead to memory leaks if page entries in the recycle ring were overwritten. To prevent this, the check to see if the recycle ring is full is changed to check if the next entry to be written is NULL. [bwh: Combine and rebase several commits so this is complete before the following buffer-packing changes. Remove module parameter.] Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2013-02-13 10:54:41 +00:00
/* Release RX buffers from the current read ptr to the write ptr */
if (rx_queue->buffer) {
sfc: reuse pages to avoid DMA mapping/unmapping costs On POWER systems, DMA mapping/unmapping operations are very expensive. These changes reduce these costs by trying to reuse DMA mapped pages. After all the buffers associated with a page have been processed and passed up, the page is placed into a ring (if there is room). For each page that is required for a refill operation, a page in the ring is examined to determine if its page count has fallen to 1, ie. the kernel has released its reference to these packets. If this is the case, the page can be immediately added back into the RX descriptor ring, without having to re-map it for DMA. If the kernel is still holding a reference to this page, it is removed from the ring and unmapped for DMA. Then a new page, which can immediately be used by RX buffers in the descriptor ring, is allocated and DMA mapped. The time a page needs to spend in the recycle ring before the kernel has released its page references is based on the number of buffers that use this page. As large pages can hold more RX buffers, the RX recycle ring can be shorter. This reduces memory usage on POWER systems, while maintaining the performance gain achieved by recycling pages, following the driver change to pack more than two RX buffers into large pages. When an IOMMU is not present, the recycle ring can be small to reduce memory usage, since DMA mapping operations are inexpensive. With a small recycle ring, attempting to refill the descriptor queue with more buffers than the equivalent size of the recycle ring could ultimately lead to memory leaks if page entries in the recycle ring were overwritten. To prevent this, the check to see if the recycle ring is full is changed to check if the next entry to be written is NULL. [bwh: Combine and rebase several commits so this is complete before the following buffer-packing changes. Remove module parameter.] Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2013-02-13 10:54:41 +00:00
for (i = rx_queue->removed_count; i < rx_queue->added_count;
i++) {
unsigned index = i & rx_queue->ptr_mask;
rx_buf = efx_rx_buffer(rx_queue, index);
efx_fini_rx_buffer(rx_queue, rx_buf);
}
}
sfc: reuse pages to avoid DMA mapping/unmapping costs On POWER systems, DMA mapping/unmapping operations are very expensive. These changes reduce these costs by trying to reuse DMA mapped pages. After all the buffers associated with a page have been processed and passed up, the page is placed into a ring (if there is room). For each page that is required for a refill operation, a page in the ring is examined to determine if its page count has fallen to 1, ie. the kernel has released its reference to these packets. If this is the case, the page can be immediately added back into the RX descriptor ring, without having to re-map it for DMA. If the kernel is still holding a reference to this page, it is removed from the ring and unmapped for DMA. Then a new page, which can immediately be used by RX buffers in the descriptor ring, is allocated and DMA mapped. The time a page needs to spend in the recycle ring before the kernel has released its page references is based on the number of buffers that use this page. As large pages can hold more RX buffers, the RX recycle ring can be shorter. This reduces memory usage on POWER systems, while maintaining the performance gain achieved by recycling pages, following the driver change to pack more than two RX buffers into large pages. When an IOMMU is not present, the recycle ring can be small to reduce memory usage, since DMA mapping operations are inexpensive. With a small recycle ring, attempting to refill the descriptor queue with more buffers than the equivalent size of the recycle ring could ultimately lead to memory leaks if page entries in the recycle ring were overwritten. To prevent this, the check to see if the recycle ring is full is changed to check if the next entry to be written is NULL. [bwh: Combine and rebase several commits so this is complete before the following buffer-packing changes. Remove module parameter.] Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
2013-02-13 10:54:41 +00:00
/* Unmap and release the pages in the recycle ring. Remove the ring. */
for (i = 0; i <= rx_queue->page_ptr_mask; i++) {
struct page *page = rx_queue->page_ring[i];
struct efx_rx_page_state *state;
if (page == NULL)
continue;
state = page_address(page);
dma_unmap_page(&efx->pci_dev->dev, state->dma_addr,
PAGE_SIZE << efx->rx_buffer_order,
DMA_FROM_DEVICE);
put_page(page);
}
kfree(rx_queue->page_ring);
rx_queue->page_ring = NULL;
if (rx_queue->xdp_rxq_info_valid)
xdp_rxq_info_unreg(&rx_queue->xdp_rxq_info);
rx_queue->xdp_rxq_info_valid = false;
}
void efx_remove_rx_queue(struct efx_rx_queue *rx_queue)
{
netif_dbg(rx_queue->efx, drv, rx_queue->efx->net_dev,
"destroying RX queue %d\n", efx_rx_queue_index(rx_queue));
efx_nic_remove_rx(rx_queue);
kfree(rx_queue->buffer);
rx_queue->buffer = NULL;
}
module_param(rx_refill_threshold, uint, 0444);
MODULE_PARM_DESC(rx_refill_threshold,
"RX descriptor ring refill threshold (%)");
#ifdef CONFIG_RFS_ACCEL
static void efx_filter_rfs_work(struct work_struct *data)
{
struct efx_async_filter_insertion *req = container_of(data, struct efx_async_filter_insertion,
work);
struct efx_nic *efx = netdev_priv(req->net_dev);
struct efx_channel *channel = efx_get_channel(efx, req->rxq_index);
int slot_idx = req - efx->rps_slot;
struct efx_arfs_rule *rule;
u16 arfs_id = 0;
int rc;
rc = efx->type->filter_insert(efx, &req->spec, true);
if (rc >= 0)
rc %= efx->type->max_rx_ip_filters;
if (efx->rps_hash_table) {
spin_lock_bh(&efx->rps_hash_lock);
rule = efx_rps_hash_find(efx, &req->spec);
/* The rule might have already gone, if someone else's request
* for the same spec was already worked and then expired before
* we got around to our work. In that case we have nothing
* tying us to an arfs_id, meaning that as soon as the filter
* is considered for expiry it will be removed.
*/
if (rule) {
if (rc < 0)
rule->filter_id = EFX_ARFS_FILTER_ID_ERROR;
else
rule->filter_id = rc;
arfs_id = rule->arfs_id;
}
spin_unlock_bh(&efx->rps_hash_lock);
}
if (rc >= 0) {
/* Remember this so we can check whether to expire the filter
* later.
*/
mutex_lock(&efx->rps_mutex);
channel->rps_flow_id[rc] = req->flow_id;
++channel->rfs_filters_added;
mutex_unlock(&efx->rps_mutex);
if (req->spec.ether_type == htons(ETH_P_IP))
netif_info(efx, rx_status, efx->net_dev,
"steering %s %pI4:%u:%pI4:%u to queue %u [flow %u filter %d id %u]\n",
(req->spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
req->spec.rem_host, ntohs(req->spec.rem_port),
req->spec.loc_host, ntohs(req->spec.loc_port),
req->rxq_index, req->flow_id, rc, arfs_id);
else
netif_info(efx, rx_status, efx->net_dev,
"steering %s [%pI6]:%u:[%pI6]:%u to queue %u [flow %u filter %d id %u]\n",
(req->spec.ip_proto == IPPROTO_TCP) ? "TCP" : "UDP",
req->spec.rem_host, ntohs(req->spec.rem_port),
req->spec.loc_host, ntohs(req->spec.loc_port),
req->rxq_index, req->flow_id, rc, arfs_id);
}
/* Release references */
clear_bit(slot_idx, &efx->rps_slot_map);
dev_put(req->net_dev);
}
int efx_filter_rfs(struct net_device *net_dev, const struct sk_buff *skb,
u16 rxq_index, u32 flow_id)
{
struct efx_nic *efx = netdev_priv(net_dev);
struct efx_async_filter_insertion *req;
struct efx_arfs_rule *rule;
struct flow_keys fk;
int slot_idx;
bool new;
int rc;
/* find a free slot */
for (slot_idx = 0; slot_idx < EFX_RPS_MAX_IN_FLIGHT; slot_idx++)
if (!test_and_set_bit(slot_idx, &efx->rps_slot_map))
break;
if (slot_idx >= EFX_RPS_MAX_IN_FLIGHT)
return -EBUSY;
if (flow_id == RPS_FLOW_ID_INVALID) {
rc = -EINVAL;
goto out_clear;
}
if (!skb_flow_dissect_flow_keys(skb, &fk, 0)) {
rc = -EPROTONOSUPPORT;
goto out_clear;
}
if (fk.basic.n_proto != htons(ETH_P_IP) && fk.basic.n_proto != htons(ETH_P_IPV6)) {
rc = -EPROTONOSUPPORT;
goto out_clear;
}
if (fk.control.flags & FLOW_DIS_IS_FRAGMENT) {
rc = -EPROTONOSUPPORT;
goto out_clear;
}
req = efx->rps_slot + slot_idx;
efx_filter_init_rx(&req->spec, EFX_FILTER_PRI_HINT,
efx->rx_scatter ? EFX_FILTER_FLAG_RX_SCATTER : 0,
rxq_index);
req->spec.match_flags =
EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_IP_PROTO |
EFX_FILTER_MATCH_LOC_HOST | EFX_FILTER_MATCH_LOC_PORT |
EFX_FILTER_MATCH_REM_HOST | EFX_FILTER_MATCH_REM_PORT;
req->spec.ether_type = fk.basic.n_proto;
req->spec.ip_proto = fk.basic.ip_proto;
if (fk.basic.n_proto == htons(ETH_P_IP)) {
req->spec.rem_host[0] = fk.addrs.v4addrs.src;
req->spec.loc_host[0] = fk.addrs.v4addrs.dst;
} else {
memcpy(req->spec.rem_host, &fk.addrs.v6addrs.src,
sizeof(struct in6_addr));
memcpy(req->spec.loc_host, &fk.addrs.v6addrs.dst,
sizeof(struct in6_addr));
}
req->spec.rem_port = fk.ports.src;
req->spec.loc_port = fk.ports.dst;
if (efx->rps_hash_table) {
/* Add it to ARFS hash table */
spin_lock(&efx->rps_hash_lock);
rule = efx_rps_hash_add(efx, &req->spec, &new);
if (!rule) {
rc = -ENOMEM;
goto out_unlock;
}
if (new)
rule->arfs_id = efx->rps_next_id++ % RPS_NO_FILTER;
rc = rule->arfs_id;
/* Skip if existing or pending filter already does the right thing */
if (!new && rule->rxq_index == rxq_index &&
rule->filter_id >= EFX_ARFS_FILTER_ID_PENDING)
goto out_unlock;
rule->rxq_index = rxq_index;
rule->filter_id = EFX_ARFS_FILTER_ID_PENDING;
spin_unlock(&efx->rps_hash_lock);
} else {
/* Without an ARFS hash table, we just use arfs_id 0 for all
* filters. This means if multiple flows hash to the same
* flow_id, all but the most recently touched will be eligible
* for expiry.
*/
rc = 0;
}
/* Queue the request */
dev_hold(req->net_dev = net_dev);
INIT_WORK(&req->work, efx_filter_rfs_work);
req->rxq_index = rxq_index;
req->flow_id = flow_id;
schedule_work(&req->work);
return rc;
out_unlock:
spin_unlock(&efx->rps_hash_lock);
out_clear:
clear_bit(slot_idx, &efx->rps_slot_map);
return rc;
}
bool __efx_filter_rfs_expire(struct efx_nic *efx, unsigned int quota)
{
bool (*expire_one)(struct efx_nic *efx, u32 flow_id, unsigned int index);
unsigned int channel_idx, index, size;
u32 flow_id;
if (!mutex_trylock(&efx->rps_mutex))
return false;
expire_one = efx->type->filter_rfs_expire_one;
channel_idx = efx->rps_expire_channel;
index = efx->rps_expire_index;
size = efx->type->max_rx_ip_filters;
while (quota--) {
struct efx_channel *channel = efx_get_channel(efx, channel_idx);
flow_id = channel->rps_flow_id[index];
if (flow_id != RPS_FLOW_ID_INVALID &&
expire_one(efx, flow_id, index)) {
netif_info(efx, rx_status, efx->net_dev,
"expired filter %d [queue %u flow %u]\n",
index, channel_idx, flow_id);
channel->rps_flow_id[index] = RPS_FLOW_ID_INVALID;
}
if (++index == size) {
if (++channel_idx == efx->n_channels)
channel_idx = 0;
index = 0;
}
}
efx->rps_expire_channel = channel_idx;
efx->rps_expire_index = index;
mutex_unlock(&efx->rps_mutex);
return true;
}
#endif /* CONFIG_RFS_ACCEL */
/**
* efx_filter_is_mc_recipient - test whether spec is a multicast recipient
* @spec: Specification to test
*
* Return: %true if the specification is a non-drop RX filter that
* matches a local MAC address I/G bit value of 1 or matches a local
* IPv4 or IPv6 address value in the respective multicast address
* range. Otherwise %false.
*/
bool efx_filter_is_mc_recipient(const struct efx_filter_spec *spec)
{
if (!(spec->flags & EFX_FILTER_FLAG_RX) ||
spec->dmaq_id == EFX_FILTER_RX_DMAQ_ID_DROP)
return false;
if (spec->match_flags &
(EFX_FILTER_MATCH_LOC_MAC | EFX_FILTER_MATCH_LOC_MAC_IG) &&
is_multicast_ether_addr(spec->loc_mac))
return true;
if ((spec->match_flags &
(EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_LOC_HOST)) ==
(EFX_FILTER_MATCH_ETHER_TYPE | EFX_FILTER_MATCH_LOC_HOST)) {
if (spec->ether_type == htons(ETH_P_IP) &&
ipv4_is_multicast(spec->loc_host[0]))
return true;
if (spec->ether_type == htons(ETH_P_IPV6) &&
((const u8 *)spec->loc_host)[0] == 0xff)
return true;
}
return false;
}