mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 01:10:04 +00:00
![Linus Torvalds](/assets/img/avatar_default.png)
This is mostly updates of the usual suspects: lpfc, qla2xxx, hisi_sas, megaraid_sas, zfcp and a host of minor updates. The major driver change here is the elimination of the block based cciss driver in favour of the SCSI based hpsa driver (which now drives all the legacy cases cciss used to be required for). Plus a reset handler clean up and the redo of the SAS SMP handler to use bsg lib. Signed-off-by: James E.J. Bottomley <jejb@linux.vnet.ibm.com> -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAABAgAGBQJZscDNAAoJEAVr7HOZEZN4DWIQAK/UkkrvKpV/jLATM/yi7CoL QidY86Hmwwl7A9HQ+2fjLfAsye0xcCzRwkucKK90IP5b4pefHhiJJfiMKAAe3TUW xstnY5z5jaOhDG4nyJFoSm5fH5qXkMnJ8NZRK8f6Qg5yBN5dStEKqoBboNsz4KBI md7idw0mbp5i2GXlJwSpc5eDS97GiPL6WkwgGaGKfXF1NDau0GbEdjijfz55haCD pMhY7WJh/71RfOq/1ThXT1Z3khOlVcKXrkdO+602n7zh/klRBRtBC8m2a6xCfZPj n7Pb/s0jhCQPd+e/Xtv7WEbY8uNOCrGoVgZ6U5EGrT5IeTfep24ackYqerjMhE63 esi4BJY8lUP9SGleLMgjYWyCHdmxBJRa7UI614DWN/H0QoGP6j/2EzGoi5Fw04vC H8/+aqPPWZc9KUBioRYo8xWO8YgMqL2eyXY+Tc9cwxqAe2T6k/NC1zJVgDFKXfzb QoWW4v9NNmYwf5vL/7tNgkeTMFQV66yUR7dR3SGTSk8UIrJ40ok0JyUAsDg86ZAH BfMkWwhWQ6Byoel0Y7Ti88T49Cox/64r/I0ux06Qgg99+KpRLT7z20+GLIEHgXxg 116C39rgvYKqzc7W8RCyj8qSROuMVzg6QFbB6n+1PEsYIX2O8A2Re3jdS34q2LbX aBDm/Lfdl4kkJrV9xY6P =nQUG -----END PGP SIGNATURE----- Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi Pull SCSI updates from James Bottomley: "This is mostly updates of the usual suspects: lpfc, qla2xxx, hisi_sas, megaraid_sas, zfcp and a host of minor updates. The major driver change here is the elimination of the block based cciss driver in favour of the SCSI based hpsa driver (which now drives all the legacy cases cciss used to be required for). Plus a reset handler clean up and the redo of the SAS SMP handler to use bsg lib" * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (279 commits) scsi: scsi-mq: Always unprepare before requeuing a request scsi: Show .retries and .jiffies_at_alloc in debugfs scsi: Improve requeuing behavior scsi: Call scsi_initialize_rq() for filesystem requests scsi: qla2xxx: Reset the logo flag, after target re-login. scsi: qla2xxx: Fix slow mem alloc behind lock scsi: qla2xxx: Clear fc4f_nvme flag scsi: qla2xxx: add missing includes for qla_isr scsi: qla2xxx: Fix an integer overflow in sysfs code scsi: aacraid: report -ENOMEM to upper layer from aac_convert_sgraw2() scsi: aacraid: get rid of one level of indentation scsi: aacraid: fix indentation errors scsi: storvsc: fix memory leak on ring buffer busy scsi: scsi_transport_sas: switch to bsg-lib for SMP passthrough scsi: smartpqi: remove the smp_handler stub scsi: hpsa: remove the smp_handler stub scsi: bsg-lib: pass the release callback through bsg_setup_queue scsi: Rework handling of scsi_device.vpd_pg8[03] scsi: Rework the code for caching Vital Product Data (VPD) scsi: rcu: Introduce rcu_swap_protected() ...
1255 lines
34 KiB
C
1255 lines
34 KiB
C
/* Virtio ring implementation.
|
|
*
|
|
* Copyright 2007 Rusty Russell IBM Corporation
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
#include <linux/virtio.h>
|
|
#include <linux/virtio_ring.h>
|
|
#include <linux/virtio_config.h>
|
|
#include <linux/device.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/module.h>
|
|
#include <linux/hrtimer.h>
|
|
#include <linux/kmemleak.h>
|
|
#include <linux/dma-mapping.h>
|
|
#include <xen/xen.h>
|
|
|
|
#ifdef DEBUG
|
|
/* For development, we want to crash whenever the ring is screwed. */
|
|
#define BAD_RING(_vq, fmt, args...) \
|
|
do { \
|
|
dev_err(&(_vq)->vq.vdev->dev, \
|
|
"%s:"fmt, (_vq)->vq.name, ##args); \
|
|
BUG(); \
|
|
} while (0)
|
|
/* Caller is supposed to guarantee no reentry. */
|
|
#define START_USE(_vq) \
|
|
do { \
|
|
if ((_vq)->in_use) \
|
|
panic("%s:in_use = %i\n", \
|
|
(_vq)->vq.name, (_vq)->in_use); \
|
|
(_vq)->in_use = __LINE__; \
|
|
} while (0)
|
|
#define END_USE(_vq) \
|
|
do { BUG_ON(!(_vq)->in_use); (_vq)->in_use = 0; } while(0)
|
|
#else
|
|
#define BAD_RING(_vq, fmt, args...) \
|
|
do { \
|
|
dev_err(&_vq->vq.vdev->dev, \
|
|
"%s:"fmt, (_vq)->vq.name, ##args); \
|
|
(_vq)->broken = true; \
|
|
} while (0)
|
|
#define START_USE(vq)
|
|
#define END_USE(vq)
|
|
#endif
|
|
|
|
struct vring_desc_state {
|
|
void *data; /* Data for callback. */
|
|
struct vring_desc *indir_desc; /* Indirect descriptor, if any. */
|
|
};
|
|
|
|
struct vring_virtqueue {
|
|
struct virtqueue vq;
|
|
|
|
/* Actual memory layout for this queue */
|
|
struct vring vring;
|
|
|
|
/* Can we use weak barriers? */
|
|
bool weak_barriers;
|
|
|
|
/* Other side has made a mess, don't try any more. */
|
|
bool broken;
|
|
|
|
/* Host supports indirect buffers */
|
|
bool indirect;
|
|
|
|
/* Host publishes avail event idx */
|
|
bool event;
|
|
|
|
/* Head of free buffer list. */
|
|
unsigned int free_head;
|
|
/* Number we've added since last sync. */
|
|
unsigned int num_added;
|
|
|
|
/* Last used index we've seen. */
|
|
u16 last_used_idx;
|
|
|
|
/* Last written value to avail->flags */
|
|
u16 avail_flags_shadow;
|
|
|
|
/* Last written value to avail->idx in guest byte order */
|
|
u16 avail_idx_shadow;
|
|
|
|
/* How to notify other side. FIXME: commonalize hcalls! */
|
|
bool (*notify)(struct virtqueue *vq);
|
|
|
|
/* DMA, allocation, and size information */
|
|
bool we_own_ring;
|
|
size_t queue_size_in_bytes;
|
|
dma_addr_t queue_dma_addr;
|
|
|
|
#ifdef DEBUG
|
|
/* They're supposed to lock for us. */
|
|
unsigned int in_use;
|
|
|
|
/* Figure out if their kicks are too delayed. */
|
|
bool last_add_time_valid;
|
|
ktime_t last_add_time;
|
|
#endif
|
|
|
|
/* Per-descriptor state. */
|
|
struct vring_desc_state desc_state[];
|
|
};
|
|
|
|
#define to_vvq(_vq) container_of(_vq, struct vring_virtqueue, vq)
|
|
|
|
/*
|
|
* Modern virtio devices have feature bits to specify whether they need a
|
|
* quirk and bypass the IOMMU. If not there, just use the DMA API.
|
|
*
|
|
* If there, the interaction between virtio and DMA API is messy.
|
|
*
|
|
* On most systems with virtio, physical addresses match bus addresses,
|
|
* and it doesn't particularly matter whether we use the DMA API.
|
|
*
|
|
* On some systems, including Xen and any system with a physical device
|
|
* that speaks virtio behind a physical IOMMU, we must use the DMA API
|
|
* for virtio DMA to work at all.
|
|
*
|
|
* On other systems, including SPARC and PPC64, virtio-pci devices are
|
|
* enumerated as though they are behind an IOMMU, but the virtio host
|
|
* ignores the IOMMU, so we must either pretend that the IOMMU isn't
|
|
* there or somehow map everything as the identity.
|
|
*
|
|
* For the time being, we preserve historic behavior and bypass the DMA
|
|
* API.
|
|
*
|
|
* TODO: install a per-device DMA ops structure that does the right thing
|
|
* taking into account all the above quirks, and use the DMA API
|
|
* unconditionally on data path.
|
|
*/
|
|
|
|
static bool vring_use_dma_api(struct virtio_device *vdev)
|
|
{
|
|
if (!virtio_has_iommu_quirk(vdev))
|
|
return true;
|
|
|
|
/* Otherwise, we are left to guess. */
|
|
/*
|
|
* In theory, it's possible to have a buggy QEMU-supposed
|
|
* emulated Q35 IOMMU and Xen enabled at the same time. On
|
|
* such a configuration, virtio has never worked and will
|
|
* not work without an even larger kludge. Instead, enable
|
|
* the DMA API if we're a Xen guest, which at least allows
|
|
* all of the sensible Xen configurations to work correctly.
|
|
*/
|
|
if (xen_domain())
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* The DMA ops on various arches are rather gnarly right now, and
|
|
* making all of the arch DMA ops work on the vring device itself
|
|
* is a mess. For now, we use the parent device for DMA ops.
|
|
*/
|
|
static inline struct device *vring_dma_dev(const struct vring_virtqueue *vq)
|
|
{
|
|
return vq->vq.vdev->dev.parent;
|
|
}
|
|
|
|
/* Map one sg entry. */
|
|
static dma_addr_t vring_map_one_sg(const struct vring_virtqueue *vq,
|
|
struct scatterlist *sg,
|
|
enum dma_data_direction direction)
|
|
{
|
|
if (!vring_use_dma_api(vq->vq.vdev))
|
|
return (dma_addr_t)sg_phys(sg);
|
|
|
|
/*
|
|
* We can't use dma_map_sg, because we don't use scatterlists in
|
|
* the way it expects (we don't guarantee that the scatterlist
|
|
* will exist for the lifetime of the mapping).
|
|
*/
|
|
return dma_map_page(vring_dma_dev(vq),
|
|
sg_page(sg), sg->offset, sg->length,
|
|
direction);
|
|
}
|
|
|
|
static dma_addr_t vring_map_single(const struct vring_virtqueue *vq,
|
|
void *cpu_addr, size_t size,
|
|
enum dma_data_direction direction)
|
|
{
|
|
if (!vring_use_dma_api(vq->vq.vdev))
|
|
return (dma_addr_t)virt_to_phys(cpu_addr);
|
|
|
|
return dma_map_single(vring_dma_dev(vq),
|
|
cpu_addr, size, direction);
|
|
}
|
|
|
|
static void vring_unmap_one(const struct vring_virtqueue *vq,
|
|
struct vring_desc *desc)
|
|
{
|
|
u16 flags;
|
|
|
|
if (!vring_use_dma_api(vq->vq.vdev))
|
|
return;
|
|
|
|
flags = virtio16_to_cpu(vq->vq.vdev, desc->flags);
|
|
|
|
if (flags & VRING_DESC_F_INDIRECT) {
|
|
dma_unmap_single(vring_dma_dev(vq),
|
|
virtio64_to_cpu(vq->vq.vdev, desc->addr),
|
|
virtio32_to_cpu(vq->vq.vdev, desc->len),
|
|
(flags & VRING_DESC_F_WRITE) ?
|
|
DMA_FROM_DEVICE : DMA_TO_DEVICE);
|
|
} else {
|
|
dma_unmap_page(vring_dma_dev(vq),
|
|
virtio64_to_cpu(vq->vq.vdev, desc->addr),
|
|
virtio32_to_cpu(vq->vq.vdev, desc->len),
|
|
(flags & VRING_DESC_F_WRITE) ?
|
|
DMA_FROM_DEVICE : DMA_TO_DEVICE);
|
|
}
|
|
}
|
|
|
|
static int vring_mapping_error(const struct vring_virtqueue *vq,
|
|
dma_addr_t addr)
|
|
{
|
|
if (!vring_use_dma_api(vq->vq.vdev))
|
|
return 0;
|
|
|
|
return dma_mapping_error(vring_dma_dev(vq), addr);
|
|
}
|
|
|
|
static struct vring_desc *alloc_indirect(struct virtqueue *_vq,
|
|
unsigned int total_sg, gfp_t gfp)
|
|
{
|
|
struct vring_desc *desc;
|
|
unsigned int i;
|
|
|
|
/*
|
|
* We require lowmem mappings for the descriptors because
|
|
* otherwise virt_to_phys will give us bogus addresses in the
|
|
* virtqueue.
|
|
*/
|
|
gfp &= ~__GFP_HIGHMEM;
|
|
|
|
desc = kmalloc(total_sg * sizeof(struct vring_desc), gfp);
|
|
if (!desc)
|
|
return NULL;
|
|
|
|
for (i = 0; i < total_sg; i++)
|
|
desc[i].next = cpu_to_virtio16(_vq->vdev, i + 1);
|
|
return desc;
|
|
}
|
|
|
|
static inline int virtqueue_add(struct virtqueue *_vq,
|
|
struct scatterlist *sgs[],
|
|
unsigned int total_sg,
|
|
unsigned int out_sgs,
|
|
unsigned int in_sgs,
|
|
void *data,
|
|
void *ctx,
|
|
gfp_t gfp)
|
|
{
|
|
struct vring_virtqueue *vq = to_vvq(_vq);
|
|
struct scatterlist *sg;
|
|
struct vring_desc *desc;
|
|
unsigned int i, n, avail, descs_used, uninitialized_var(prev), err_idx;
|
|
int head;
|
|
bool indirect;
|
|
|
|
START_USE(vq);
|
|
|
|
BUG_ON(data == NULL);
|
|
BUG_ON(ctx && vq->indirect);
|
|
|
|
if (unlikely(vq->broken)) {
|
|
END_USE(vq);
|
|
return -EIO;
|
|
}
|
|
|
|
#ifdef DEBUG
|
|
{
|
|
ktime_t now = ktime_get();
|
|
|
|
/* No kick or get, with .1 second between? Warn. */
|
|
if (vq->last_add_time_valid)
|
|
WARN_ON(ktime_to_ms(ktime_sub(now, vq->last_add_time))
|
|
> 100);
|
|
vq->last_add_time = now;
|
|
vq->last_add_time_valid = true;
|
|
}
|
|
#endif
|
|
|
|
BUG_ON(total_sg == 0);
|
|
|
|
head = vq->free_head;
|
|
|
|
/* If the host supports indirect descriptor tables, and we have multiple
|
|
* buffers, then go indirect. FIXME: tune this threshold */
|
|
if (vq->indirect && total_sg > 1 && vq->vq.num_free)
|
|
desc = alloc_indirect(_vq, total_sg, gfp);
|
|
else {
|
|
desc = NULL;
|
|
WARN_ON_ONCE(total_sg > vq->vring.num && !vq->indirect);
|
|
}
|
|
|
|
if (desc) {
|
|
/* Use a single buffer which doesn't continue */
|
|
indirect = true;
|
|
/* Set up rest to use this indirect table. */
|
|
i = 0;
|
|
descs_used = 1;
|
|
} else {
|
|
indirect = false;
|
|
desc = vq->vring.desc;
|
|
i = head;
|
|
descs_used = total_sg;
|
|
}
|
|
|
|
if (vq->vq.num_free < descs_used) {
|
|
pr_debug("Can't add buf len %i - avail = %i\n",
|
|
descs_used, vq->vq.num_free);
|
|
/* FIXME: for historical reasons, we force a notify here if
|
|
* there are outgoing parts to the buffer. Presumably the
|
|
* host should service the ring ASAP. */
|
|
if (out_sgs)
|
|
vq->notify(&vq->vq);
|
|
if (indirect)
|
|
kfree(desc);
|
|
END_USE(vq);
|
|
return -ENOSPC;
|
|
}
|
|
|
|
for (n = 0; n < out_sgs; n++) {
|
|
for (sg = sgs[n]; sg; sg = sg_next(sg)) {
|
|
dma_addr_t addr = vring_map_one_sg(vq, sg, DMA_TO_DEVICE);
|
|
if (vring_mapping_error(vq, addr))
|
|
goto unmap_release;
|
|
|
|
desc[i].flags = cpu_to_virtio16(_vq->vdev, VRING_DESC_F_NEXT);
|
|
desc[i].addr = cpu_to_virtio64(_vq->vdev, addr);
|
|
desc[i].len = cpu_to_virtio32(_vq->vdev, sg->length);
|
|
prev = i;
|
|
i = virtio16_to_cpu(_vq->vdev, desc[i].next);
|
|
}
|
|
}
|
|
for (; n < (out_sgs + in_sgs); n++) {
|
|
for (sg = sgs[n]; sg; sg = sg_next(sg)) {
|
|
dma_addr_t addr = vring_map_one_sg(vq, sg, DMA_FROM_DEVICE);
|
|
if (vring_mapping_error(vq, addr))
|
|
goto unmap_release;
|
|
|
|
desc[i].flags = cpu_to_virtio16(_vq->vdev, VRING_DESC_F_NEXT | VRING_DESC_F_WRITE);
|
|
desc[i].addr = cpu_to_virtio64(_vq->vdev, addr);
|
|
desc[i].len = cpu_to_virtio32(_vq->vdev, sg->length);
|
|
prev = i;
|
|
i = virtio16_to_cpu(_vq->vdev, desc[i].next);
|
|
}
|
|
}
|
|
/* Last one doesn't continue. */
|
|
desc[prev].flags &= cpu_to_virtio16(_vq->vdev, ~VRING_DESC_F_NEXT);
|
|
|
|
if (indirect) {
|
|
/* Now that the indirect table is filled in, map it. */
|
|
dma_addr_t addr = vring_map_single(
|
|
vq, desc, total_sg * sizeof(struct vring_desc),
|
|
DMA_TO_DEVICE);
|
|
if (vring_mapping_error(vq, addr))
|
|
goto unmap_release;
|
|
|
|
vq->vring.desc[head].flags = cpu_to_virtio16(_vq->vdev, VRING_DESC_F_INDIRECT);
|
|
vq->vring.desc[head].addr = cpu_to_virtio64(_vq->vdev, addr);
|
|
|
|
vq->vring.desc[head].len = cpu_to_virtio32(_vq->vdev, total_sg * sizeof(struct vring_desc));
|
|
}
|
|
|
|
/* We're using some buffers from the free list. */
|
|
vq->vq.num_free -= descs_used;
|
|
|
|
/* Update free pointer */
|
|
if (indirect)
|
|
vq->free_head = virtio16_to_cpu(_vq->vdev, vq->vring.desc[head].next);
|
|
else
|
|
vq->free_head = i;
|
|
|
|
/* Store token and indirect buffer state. */
|
|
vq->desc_state[head].data = data;
|
|
if (indirect)
|
|
vq->desc_state[head].indir_desc = desc;
|
|
else
|
|
vq->desc_state[head].indir_desc = ctx;
|
|
|
|
/* Put entry in available array (but don't update avail->idx until they
|
|
* do sync). */
|
|
avail = vq->avail_idx_shadow & (vq->vring.num - 1);
|
|
vq->vring.avail->ring[avail] = cpu_to_virtio16(_vq->vdev, head);
|
|
|
|
/* Descriptors and available array need to be set before we expose the
|
|
* new available array entries. */
|
|
virtio_wmb(vq->weak_barriers);
|
|
vq->avail_idx_shadow++;
|
|
vq->vring.avail->idx = cpu_to_virtio16(_vq->vdev, vq->avail_idx_shadow);
|
|
vq->num_added++;
|
|
|
|
pr_debug("Added buffer head %i to %p\n", head, vq);
|
|
END_USE(vq);
|
|
|
|
/* This is very unlikely, but theoretically possible. Kick
|
|
* just in case. */
|
|
if (unlikely(vq->num_added == (1 << 16) - 1))
|
|
virtqueue_kick(_vq);
|
|
|
|
return 0;
|
|
|
|
unmap_release:
|
|
err_idx = i;
|
|
i = head;
|
|
|
|
for (n = 0; n < total_sg; n++) {
|
|
if (i == err_idx)
|
|
break;
|
|
vring_unmap_one(vq, &desc[i]);
|
|
i = virtio16_to_cpu(_vq->vdev, vq->vring.desc[i].next);
|
|
}
|
|
|
|
vq->vq.num_free += total_sg;
|
|
|
|
if (indirect)
|
|
kfree(desc);
|
|
|
|
END_USE(vq);
|
|
return -EIO;
|
|
}
|
|
|
|
/**
|
|
* virtqueue_add_sgs - expose buffers to other end
|
|
* @vq: the struct virtqueue we're talking about.
|
|
* @sgs: array of terminated scatterlists.
|
|
* @out_num: the number of scatterlists readable by other side
|
|
* @in_num: the number of scatterlists which are writable (after readable ones)
|
|
* @data: the token identifying the buffer.
|
|
* @gfp: how to do memory allocations (if necessary).
|
|
*
|
|
* Caller must ensure we don't call this with other virtqueue operations
|
|
* at the same time (except where noted).
|
|
*
|
|
* Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
|
|
*/
|
|
int virtqueue_add_sgs(struct virtqueue *_vq,
|
|
struct scatterlist *sgs[],
|
|
unsigned int out_sgs,
|
|
unsigned int in_sgs,
|
|
void *data,
|
|
gfp_t gfp)
|
|
{
|
|
unsigned int i, total_sg = 0;
|
|
|
|
/* Count them first. */
|
|
for (i = 0; i < out_sgs + in_sgs; i++) {
|
|
struct scatterlist *sg;
|
|
for (sg = sgs[i]; sg; sg = sg_next(sg))
|
|
total_sg++;
|
|
}
|
|
return virtqueue_add(_vq, sgs, total_sg, out_sgs, in_sgs,
|
|
data, NULL, gfp);
|
|
}
|
|
EXPORT_SYMBOL_GPL(virtqueue_add_sgs);
|
|
|
|
/**
|
|
* virtqueue_add_outbuf - expose output buffers to other end
|
|
* @vq: the struct virtqueue we're talking about.
|
|
* @sg: scatterlist (must be well-formed and terminated!)
|
|
* @num: the number of entries in @sg readable by other side
|
|
* @data: the token identifying the buffer.
|
|
* @gfp: how to do memory allocations (if necessary).
|
|
*
|
|
* Caller must ensure we don't call this with other virtqueue operations
|
|
* at the same time (except where noted).
|
|
*
|
|
* Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
|
|
*/
|
|
int virtqueue_add_outbuf(struct virtqueue *vq,
|
|
struct scatterlist *sg, unsigned int num,
|
|
void *data,
|
|
gfp_t gfp)
|
|
{
|
|
return virtqueue_add(vq, &sg, num, 1, 0, data, NULL, gfp);
|
|
}
|
|
EXPORT_SYMBOL_GPL(virtqueue_add_outbuf);
|
|
|
|
/**
|
|
* virtqueue_add_inbuf - expose input buffers to other end
|
|
* @vq: the struct virtqueue we're talking about.
|
|
* @sg: scatterlist (must be well-formed and terminated!)
|
|
* @num: the number of entries in @sg writable by other side
|
|
* @data: the token identifying the buffer.
|
|
* @gfp: how to do memory allocations (if necessary).
|
|
*
|
|
* Caller must ensure we don't call this with other virtqueue operations
|
|
* at the same time (except where noted).
|
|
*
|
|
* Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
|
|
*/
|
|
int virtqueue_add_inbuf(struct virtqueue *vq,
|
|
struct scatterlist *sg, unsigned int num,
|
|
void *data,
|
|
gfp_t gfp)
|
|
{
|
|
return virtqueue_add(vq, &sg, num, 0, 1, data, NULL, gfp);
|
|
}
|
|
EXPORT_SYMBOL_GPL(virtqueue_add_inbuf);
|
|
|
|
/**
|
|
* virtqueue_add_inbuf_ctx - expose input buffers to other end
|
|
* @vq: the struct virtqueue we're talking about.
|
|
* @sg: scatterlist (must be well-formed and terminated!)
|
|
* @num: the number of entries in @sg writable by other side
|
|
* @data: the token identifying the buffer.
|
|
* @ctx: extra context for the token
|
|
* @gfp: how to do memory allocations (if necessary).
|
|
*
|
|
* Caller must ensure we don't call this with other virtqueue operations
|
|
* at the same time (except where noted).
|
|
*
|
|
* Returns zero or a negative error (ie. ENOSPC, ENOMEM, EIO).
|
|
*/
|
|
int virtqueue_add_inbuf_ctx(struct virtqueue *vq,
|
|
struct scatterlist *sg, unsigned int num,
|
|
void *data,
|
|
void *ctx,
|
|
gfp_t gfp)
|
|
{
|
|
return virtqueue_add(vq, &sg, num, 0, 1, data, ctx, gfp);
|
|
}
|
|
EXPORT_SYMBOL_GPL(virtqueue_add_inbuf_ctx);
|
|
|
|
/**
|
|
* virtqueue_kick_prepare - first half of split virtqueue_kick call.
|
|
* @vq: the struct virtqueue
|
|
*
|
|
* Instead of virtqueue_kick(), you can do:
|
|
* if (virtqueue_kick_prepare(vq))
|
|
* virtqueue_notify(vq);
|
|
*
|
|
* This is sometimes useful because the virtqueue_kick_prepare() needs
|
|
* to be serialized, but the actual virtqueue_notify() call does not.
|
|
*/
|
|
bool virtqueue_kick_prepare(struct virtqueue *_vq)
|
|
{
|
|
struct vring_virtqueue *vq = to_vvq(_vq);
|
|
u16 new, old;
|
|
bool needs_kick;
|
|
|
|
START_USE(vq);
|
|
/* We need to expose available array entries before checking avail
|
|
* event. */
|
|
virtio_mb(vq->weak_barriers);
|
|
|
|
old = vq->avail_idx_shadow - vq->num_added;
|
|
new = vq->avail_idx_shadow;
|
|
vq->num_added = 0;
|
|
|
|
#ifdef DEBUG
|
|
if (vq->last_add_time_valid) {
|
|
WARN_ON(ktime_to_ms(ktime_sub(ktime_get(),
|
|
vq->last_add_time)) > 100);
|
|
}
|
|
vq->last_add_time_valid = false;
|
|
#endif
|
|
|
|
if (vq->event) {
|
|
needs_kick = vring_need_event(virtio16_to_cpu(_vq->vdev, vring_avail_event(&vq->vring)),
|
|
new, old);
|
|
} else {
|
|
needs_kick = !(vq->vring.used->flags & cpu_to_virtio16(_vq->vdev, VRING_USED_F_NO_NOTIFY));
|
|
}
|
|
END_USE(vq);
|
|
return needs_kick;
|
|
}
|
|
EXPORT_SYMBOL_GPL(virtqueue_kick_prepare);
|
|
|
|
/**
|
|
* virtqueue_notify - second half of split virtqueue_kick call.
|
|
* @vq: the struct virtqueue
|
|
*
|
|
* This does not need to be serialized.
|
|
*
|
|
* Returns false if host notify failed or queue is broken, otherwise true.
|
|
*/
|
|
bool virtqueue_notify(struct virtqueue *_vq)
|
|
{
|
|
struct vring_virtqueue *vq = to_vvq(_vq);
|
|
|
|
if (unlikely(vq->broken))
|
|
return false;
|
|
|
|
/* Prod other side to tell it about changes. */
|
|
if (!vq->notify(_vq)) {
|
|
vq->broken = true;
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
EXPORT_SYMBOL_GPL(virtqueue_notify);
|
|
|
|
/**
|
|
* virtqueue_kick - update after add_buf
|
|
* @vq: the struct virtqueue
|
|
*
|
|
* After one or more virtqueue_add_* calls, invoke this to kick
|
|
* the other side.
|
|
*
|
|
* Caller must ensure we don't call this with other virtqueue
|
|
* operations at the same time (except where noted).
|
|
*
|
|
* Returns false if kick failed, otherwise true.
|
|
*/
|
|
bool virtqueue_kick(struct virtqueue *vq)
|
|
{
|
|
if (virtqueue_kick_prepare(vq))
|
|
return virtqueue_notify(vq);
|
|
return true;
|
|
}
|
|
EXPORT_SYMBOL_GPL(virtqueue_kick);
|
|
|
|
static void detach_buf(struct vring_virtqueue *vq, unsigned int head,
|
|
void **ctx)
|
|
{
|
|
unsigned int i, j;
|
|
__virtio16 nextflag = cpu_to_virtio16(vq->vq.vdev, VRING_DESC_F_NEXT);
|
|
|
|
/* Clear data ptr. */
|
|
vq->desc_state[head].data = NULL;
|
|
|
|
/* Put back on free list: unmap first-level descriptors and find end */
|
|
i = head;
|
|
|
|
while (vq->vring.desc[i].flags & nextflag) {
|
|
vring_unmap_one(vq, &vq->vring.desc[i]);
|
|
i = virtio16_to_cpu(vq->vq.vdev, vq->vring.desc[i].next);
|
|
vq->vq.num_free++;
|
|
}
|
|
|
|
vring_unmap_one(vq, &vq->vring.desc[i]);
|
|
vq->vring.desc[i].next = cpu_to_virtio16(vq->vq.vdev, vq->free_head);
|
|
vq->free_head = head;
|
|
|
|
/* Plus final descriptor */
|
|
vq->vq.num_free++;
|
|
|
|
if (vq->indirect) {
|
|
struct vring_desc *indir_desc = vq->desc_state[head].indir_desc;
|
|
u32 len;
|
|
|
|
/* Free the indirect table, if any, now that it's unmapped. */
|
|
if (!indir_desc)
|
|
return;
|
|
|
|
len = virtio32_to_cpu(vq->vq.vdev, vq->vring.desc[head].len);
|
|
|
|
BUG_ON(!(vq->vring.desc[head].flags &
|
|
cpu_to_virtio16(vq->vq.vdev, VRING_DESC_F_INDIRECT)));
|
|
BUG_ON(len == 0 || len % sizeof(struct vring_desc));
|
|
|
|
for (j = 0; j < len / sizeof(struct vring_desc); j++)
|
|
vring_unmap_one(vq, &indir_desc[j]);
|
|
|
|
kfree(indir_desc);
|
|
vq->desc_state[head].indir_desc = NULL;
|
|
} else if (ctx) {
|
|
*ctx = vq->desc_state[head].indir_desc;
|
|
}
|
|
}
|
|
|
|
static inline bool more_used(const struct vring_virtqueue *vq)
|
|
{
|
|
return vq->last_used_idx != virtio16_to_cpu(vq->vq.vdev, vq->vring.used->idx);
|
|
}
|
|
|
|
/**
|
|
* virtqueue_get_buf - get the next used buffer
|
|
* @vq: the struct virtqueue we're talking about.
|
|
* @len: the length written into the buffer
|
|
*
|
|
* If the device wrote data into the buffer, @len will be set to the
|
|
* amount written. This means you don't need to clear the buffer
|
|
* beforehand to ensure there's no data leakage in the case of short
|
|
* writes.
|
|
*
|
|
* Caller must ensure we don't call this with other virtqueue
|
|
* operations at the same time (except where noted).
|
|
*
|
|
* Returns NULL if there are no used buffers, or the "data" token
|
|
* handed to virtqueue_add_*().
|
|
*/
|
|
void *virtqueue_get_buf_ctx(struct virtqueue *_vq, unsigned int *len,
|
|
void **ctx)
|
|
{
|
|
struct vring_virtqueue *vq = to_vvq(_vq);
|
|
void *ret;
|
|
unsigned int i;
|
|
u16 last_used;
|
|
|
|
START_USE(vq);
|
|
|
|
if (unlikely(vq->broken)) {
|
|
END_USE(vq);
|
|
return NULL;
|
|
}
|
|
|
|
if (!more_used(vq)) {
|
|
pr_debug("No more buffers in queue\n");
|
|
END_USE(vq);
|
|
return NULL;
|
|
}
|
|
|
|
/* Only get used array entries after they have been exposed by host. */
|
|
virtio_rmb(vq->weak_barriers);
|
|
|
|
last_used = (vq->last_used_idx & (vq->vring.num - 1));
|
|
i = virtio32_to_cpu(_vq->vdev, vq->vring.used->ring[last_used].id);
|
|
*len = virtio32_to_cpu(_vq->vdev, vq->vring.used->ring[last_used].len);
|
|
|
|
if (unlikely(i >= vq->vring.num)) {
|
|
BAD_RING(vq, "id %u out of range\n", i);
|
|
return NULL;
|
|
}
|
|
if (unlikely(!vq->desc_state[i].data)) {
|
|
BAD_RING(vq, "id %u is not a head!\n", i);
|
|
return NULL;
|
|
}
|
|
|
|
/* detach_buf clears data, so grab it now. */
|
|
ret = vq->desc_state[i].data;
|
|
detach_buf(vq, i, ctx);
|
|
vq->last_used_idx++;
|
|
/* If we expect an interrupt for the next entry, tell host
|
|
* by writing event index and flush out the write before
|
|
* the read in the next get_buf call. */
|
|
if (!(vq->avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT))
|
|
virtio_store_mb(vq->weak_barriers,
|
|
&vring_used_event(&vq->vring),
|
|
cpu_to_virtio16(_vq->vdev, vq->last_used_idx));
|
|
|
|
#ifdef DEBUG
|
|
vq->last_add_time_valid = false;
|
|
#endif
|
|
|
|
END_USE(vq);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(virtqueue_get_buf_ctx);
|
|
|
|
void *virtqueue_get_buf(struct virtqueue *_vq, unsigned int *len)
|
|
{
|
|
return virtqueue_get_buf_ctx(_vq, len, NULL);
|
|
}
|
|
EXPORT_SYMBOL_GPL(virtqueue_get_buf);
|
|
/**
|
|
* virtqueue_disable_cb - disable callbacks
|
|
* @vq: the struct virtqueue we're talking about.
|
|
*
|
|
* Note that this is not necessarily synchronous, hence unreliable and only
|
|
* useful as an optimization.
|
|
*
|
|
* Unlike other operations, this need not be serialized.
|
|
*/
|
|
void virtqueue_disable_cb(struct virtqueue *_vq)
|
|
{
|
|
struct vring_virtqueue *vq = to_vvq(_vq);
|
|
|
|
if (!(vq->avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT)) {
|
|
vq->avail_flags_shadow |= VRING_AVAIL_F_NO_INTERRUPT;
|
|
if (!vq->event)
|
|
vq->vring.avail->flags = cpu_to_virtio16(_vq->vdev, vq->avail_flags_shadow);
|
|
}
|
|
|
|
}
|
|
EXPORT_SYMBOL_GPL(virtqueue_disable_cb);
|
|
|
|
/**
|
|
* virtqueue_enable_cb_prepare - restart callbacks after disable_cb
|
|
* @vq: the struct virtqueue we're talking about.
|
|
*
|
|
* This re-enables callbacks; it returns current queue state
|
|
* in an opaque unsigned value. This value should be later tested by
|
|
* virtqueue_poll, to detect a possible race between the driver checking for
|
|
* more work, and enabling callbacks.
|
|
*
|
|
* Caller must ensure we don't call this with other virtqueue
|
|
* operations at the same time (except where noted).
|
|
*/
|
|
unsigned virtqueue_enable_cb_prepare(struct virtqueue *_vq)
|
|
{
|
|
struct vring_virtqueue *vq = to_vvq(_vq);
|
|
u16 last_used_idx;
|
|
|
|
START_USE(vq);
|
|
|
|
/* We optimistically turn back on interrupts, then check if there was
|
|
* more to do. */
|
|
/* Depending on the VIRTIO_RING_F_EVENT_IDX feature, we need to
|
|
* either clear the flags bit or point the event index at the next
|
|
* entry. Always do both to keep code simple. */
|
|
if (vq->avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT) {
|
|
vq->avail_flags_shadow &= ~VRING_AVAIL_F_NO_INTERRUPT;
|
|
if (!vq->event)
|
|
vq->vring.avail->flags = cpu_to_virtio16(_vq->vdev, vq->avail_flags_shadow);
|
|
}
|
|
vring_used_event(&vq->vring) = cpu_to_virtio16(_vq->vdev, last_used_idx = vq->last_used_idx);
|
|
END_USE(vq);
|
|
return last_used_idx;
|
|
}
|
|
EXPORT_SYMBOL_GPL(virtqueue_enable_cb_prepare);
|
|
|
|
/**
|
|
* virtqueue_poll - query pending used buffers
|
|
* @vq: the struct virtqueue we're talking about.
|
|
* @last_used_idx: virtqueue state (from call to virtqueue_enable_cb_prepare).
|
|
*
|
|
* Returns "true" if there are pending used buffers in the queue.
|
|
*
|
|
* This does not need to be serialized.
|
|
*/
|
|
bool virtqueue_poll(struct virtqueue *_vq, unsigned last_used_idx)
|
|
{
|
|
struct vring_virtqueue *vq = to_vvq(_vq);
|
|
|
|
virtio_mb(vq->weak_barriers);
|
|
return (u16)last_used_idx != virtio16_to_cpu(_vq->vdev, vq->vring.used->idx);
|
|
}
|
|
EXPORT_SYMBOL_GPL(virtqueue_poll);
|
|
|
|
/**
|
|
* virtqueue_enable_cb - restart callbacks after disable_cb.
|
|
* @vq: the struct virtqueue we're talking about.
|
|
*
|
|
* This re-enables callbacks; it returns "false" if there are pending
|
|
* buffers in the queue, to detect a possible race between the driver
|
|
* checking for more work, and enabling callbacks.
|
|
*
|
|
* Caller must ensure we don't call this with other virtqueue
|
|
* operations at the same time (except where noted).
|
|
*/
|
|
bool virtqueue_enable_cb(struct virtqueue *_vq)
|
|
{
|
|
unsigned last_used_idx = virtqueue_enable_cb_prepare(_vq);
|
|
return !virtqueue_poll(_vq, last_used_idx);
|
|
}
|
|
EXPORT_SYMBOL_GPL(virtqueue_enable_cb);
|
|
|
|
/**
|
|
* virtqueue_enable_cb_delayed - restart callbacks after disable_cb.
|
|
* @vq: the struct virtqueue we're talking about.
|
|
*
|
|
* This re-enables callbacks but hints to the other side to delay
|
|
* interrupts until most of the available buffers have been processed;
|
|
* it returns "false" if there are many pending buffers in the queue,
|
|
* to detect a possible race between the driver checking for more work,
|
|
* and enabling callbacks.
|
|
*
|
|
* Caller must ensure we don't call this with other virtqueue
|
|
* operations at the same time (except where noted).
|
|
*/
|
|
bool virtqueue_enable_cb_delayed(struct virtqueue *_vq)
|
|
{
|
|
struct vring_virtqueue *vq = to_vvq(_vq);
|
|
u16 bufs;
|
|
|
|
START_USE(vq);
|
|
|
|
/* We optimistically turn back on interrupts, then check if there was
|
|
* more to do. */
|
|
/* Depending on the VIRTIO_RING_F_USED_EVENT_IDX feature, we need to
|
|
* either clear the flags bit or point the event index at the next
|
|
* entry. Always update the event index to keep code simple. */
|
|
if (vq->avail_flags_shadow & VRING_AVAIL_F_NO_INTERRUPT) {
|
|
vq->avail_flags_shadow &= ~VRING_AVAIL_F_NO_INTERRUPT;
|
|
if (!vq->event)
|
|
vq->vring.avail->flags = cpu_to_virtio16(_vq->vdev, vq->avail_flags_shadow);
|
|
}
|
|
/* TODO: tune this threshold */
|
|
bufs = (u16)(vq->avail_idx_shadow - vq->last_used_idx) * 3 / 4;
|
|
|
|
virtio_store_mb(vq->weak_barriers,
|
|
&vring_used_event(&vq->vring),
|
|
cpu_to_virtio16(_vq->vdev, vq->last_used_idx + bufs));
|
|
|
|
if (unlikely((u16)(virtio16_to_cpu(_vq->vdev, vq->vring.used->idx) - vq->last_used_idx) > bufs)) {
|
|
END_USE(vq);
|
|
return false;
|
|
}
|
|
|
|
END_USE(vq);
|
|
return true;
|
|
}
|
|
EXPORT_SYMBOL_GPL(virtqueue_enable_cb_delayed);
|
|
|
|
/**
|
|
* virtqueue_detach_unused_buf - detach first unused buffer
|
|
* @vq: the struct virtqueue we're talking about.
|
|
*
|
|
* Returns NULL or the "data" token handed to virtqueue_add_*().
|
|
* This is not valid on an active queue; it is useful only for device
|
|
* shutdown.
|
|
*/
|
|
void *virtqueue_detach_unused_buf(struct virtqueue *_vq)
|
|
{
|
|
struct vring_virtqueue *vq = to_vvq(_vq);
|
|
unsigned int i;
|
|
void *buf;
|
|
|
|
START_USE(vq);
|
|
|
|
for (i = 0; i < vq->vring.num; i++) {
|
|
if (!vq->desc_state[i].data)
|
|
continue;
|
|
/* detach_buf clears data, so grab it now. */
|
|
buf = vq->desc_state[i].data;
|
|
detach_buf(vq, i, NULL);
|
|
vq->avail_idx_shadow--;
|
|
vq->vring.avail->idx = cpu_to_virtio16(_vq->vdev, vq->avail_idx_shadow);
|
|
END_USE(vq);
|
|
return buf;
|
|
}
|
|
/* That should have freed everything. */
|
|
BUG_ON(vq->vq.num_free != vq->vring.num);
|
|
|
|
END_USE(vq);
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL_GPL(virtqueue_detach_unused_buf);
|
|
|
|
irqreturn_t vring_interrupt(int irq, void *_vq)
|
|
{
|
|
struct vring_virtqueue *vq = to_vvq(_vq);
|
|
|
|
if (!more_used(vq)) {
|
|
pr_debug("virtqueue interrupt with no work for %p\n", vq);
|
|
return IRQ_NONE;
|
|
}
|
|
|
|
if (unlikely(vq->broken))
|
|
return IRQ_HANDLED;
|
|
|
|
pr_debug("virtqueue callback for %p (%p)\n", vq, vq->vq.callback);
|
|
if (vq->vq.callback)
|
|
vq->vq.callback(&vq->vq);
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
EXPORT_SYMBOL_GPL(vring_interrupt);
|
|
|
|
struct virtqueue *__vring_new_virtqueue(unsigned int index,
|
|
struct vring vring,
|
|
struct virtio_device *vdev,
|
|
bool weak_barriers,
|
|
bool context,
|
|
bool (*notify)(struct virtqueue *),
|
|
void (*callback)(struct virtqueue *),
|
|
const char *name)
|
|
{
|
|
unsigned int i;
|
|
struct vring_virtqueue *vq;
|
|
|
|
vq = kmalloc(sizeof(*vq) + vring.num * sizeof(struct vring_desc_state),
|
|
GFP_KERNEL);
|
|
if (!vq)
|
|
return NULL;
|
|
|
|
vq->vring = vring;
|
|
vq->vq.callback = callback;
|
|
vq->vq.vdev = vdev;
|
|
vq->vq.name = name;
|
|
vq->vq.num_free = vring.num;
|
|
vq->vq.index = index;
|
|
vq->we_own_ring = false;
|
|
vq->queue_dma_addr = 0;
|
|
vq->queue_size_in_bytes = 0;
|
|
vq->notify = notify;
|
|
vq->weak_barriers = weak_barriers;
|
|
vq->broken = false;
|
|
vq->last_used_idx = 0;
|
|
vq->avail_flags_shadow = 0;
|
|
vq->avail_idx_shadow = 0;
|
|
vq->num_added = 0;
|
|
list_add_tail(&vq->vq.list, &vdev->vqs);
|
|
#ifdef DEBUG
|
|
vq->in_use = false;
|
|
vq->last_add_time_valid = false;
|
|
#endif
|
|
|
|
vq->indirect = virtio_has_feature(vdev, VIRTIO_RING_F_INDIRECT_DESC) &&
|
|
!context;
|
|
vq->event = virtio_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX);
|
|
|
|
/* No callback? Tell other side not to bother us. */
|
|
if (!callback) {
|
|
vq->avail_flags_shadow |= VRING_AVAIL_F_NO_INTERRUPT;
|
|
if (!vq->event)
|
|
vq->vring.avail->flags = cpu_to_virtio16(vdev, vq->avail_flags_shadow);
|
|
}
|
|
|
|
/* Put everything in free lists. */
|
|
vq->free_head = 0;
|
|
for (i = 0; i < vring.num-1; i++)
|
|
vq->vring.desc[i].next = cpu_to_virtio16(vdev, i + 1);
|
|
memset(vq->desc_state, 0, vring.num * sizeof(struct vring_desc_state));
|
|
|
|
return &vq->vq;
|
|
}
|
|
EXPORT_SYMBOL_GPL(__vring_new_virtqueue);
|
|
|
|
static void *vring_alloc_queue(struct virtio_device *vdev, size_t size,
|
|
dma_addr_t *dma_handle, gfp_t flag)
|
|
{
|
|
if (vring_use_dma_api(vdev)) {
|
|
return dma_alloc_coherent(vdev->dev.parent, size,
|
|
dma_handle, flag);
|
|
} else {
|
|
void *queue = alloc_pages_exact(PAGE_ALIGN(size), flag);
|
|
if (queue) {
|
|
phys_addr_t phys_addr = virt_to_phys(queue);
|
|
*dma_handle = (dma_addr_t)phys_addr;
|
|
|
|
/*
|
|
* Sanity check: make sure we dind't truncate
|
|
* the address. The only arches I can find that
|
|
* have 64-bit phys_addr_t but 32-bit dma_addr_t
|
|
* are certain non-highmem MIPS and x86
|
|
* configurations, but these configurations
|
|
* should never allocate physical pages above 32
|
|
* bits, so this is fine. Just in case, throw a
|
|
* warning and abort if we end up with an
|
|
* unrepresentable address.
|
|
*/
|
|
if (WARN_ON_ONCE(*dma_handle != phys_addr)) {
|
|
free_pages_exact(queue, PAGE_ALIGN(size));
|
|
return NULL;
|
|
}
|
|
}
|
|
return queue;
|
|
}
|
|
}
|
|
|
|
static void vring_free_queue(struct virtio_device *vdev, size_t size,
|
|
void *queue, dma_addr_t dma_handle)
|
|
{
|
|
if (vring_use_dma_api(vdev)) {
|
|
dma_free_coherent(vdev->dev.parent, size, queue, dma_handle);
|
|
} else {
|
|
free_pages_exact(queue, PAGE_ALIGN(size));
|
|
}
|
|
}
|
|
|
|
struct virtqueue *vring_create_virtqueue(
|
|
unsigned int index,
|
|
unsigned int num,
|
|
unsigned int vring_align,
|
|
struct virtio_device *vdev,
|
|
bool weak_barriers,
|
|
bool may_reduce_num,
|
|
bool context,
|
|
bool (*notify)(struct virtqueue *),
|
|
void (*callback)(struct virtqueue *),
|
|
const char *name)
|
|
{
|
|
struct virtqueue *vq;
|
|
void *queue = NULL;
|
|
dma_addr_t dma_addr;
|
|
size_t queue_size_in_bytes;
|
|
struct vring vring;
|
|
|
|
/* We assume num is a power of 2. */
|
|
if (num & (num - 1)) {
|
|
dev_warn(&vdev->dev, "Bad virtqueue length %u\n", num);
|
|
return NULL;
|
|
}
|
|
|
|
/* TODO: allocate each queue chunk individually */
|
|
for (; num && vring_size(num, vring_align) > PAGE_SIZE; num /= 2) {
|
|
queue = vring_alloc_queue(vdev, vring_size(num, vring_align),
|
|
&dma_addr,
|
|
GFP_KERNEL|__GFP_NOWARN|__GFP_ZERO);
|
|
if (queue)
|
|
break;
|
|
}
|
|
|
|
if (!num)
|
|
return NULL;
|
|
|
|
if (!queue) {
|
|
/* Try to get a single page. You are my only hope! */
|
|
queue = vring_alloc_queue(vdev, vring_size(num, vring_align),
|
|
&dma_addr, GFP_KERNEL|__GFP_ZERO);
|
|
}
|
|
if (!queue)
|
|
return NULL;
|
|
|
|
queue_size_in_bytes = vring_size(num, vring_align);
|
|
vring_init(&vring, num, queue, vring_align);
|
|
|
|
vq = __vring_new_virtqueue(index, vring, vdev, weak_barriers, context,
|
|
notify, callback, name);
|
|
if (!vq) {
|
|
vring_free_queue(vdev, queue_size_in_bytes, queue,
|
|
dma_addr);
|
|
return NULL;
|
|
}
|
|
|
|
to_vvq(vq)->queue_dma_addr = dma_addr;
|
|
to_vvq(vq)->queue_size_in_bytes = queue_size_in_bytes;
|
|
to_vvq(vq)->we_own_ring = true;
|
|
|
|
return vq;
|
|
}
|
|
EXPORT_SYMBOL_GPL(vring_create_virtqueue);
|
|
|
|
struct virtqueue *vring_new_virtqueue(unsigned int index,
|
|
unsigned int num,
|
|
unsigned int vring_align,
|
|
struct virtio_device *vdev,
|
|
bool weak_barriers,
|
|
bool context,
|
|
void *pages,
|
|
bool (*notify)(struct virtqueue *vq),
|
|
void (*callback)(struct virtqueue *vq),
|
|
const char *name)
|
|
{
|
|
struct vring vring;
|
|
vring_init(&vring, num, pages, vring_align);
|
|
return __vring_new_virtqueue(index, vring, vdev, weak_barriers, context,
|
|
notify, callback, name);
|
|
}
|
|
EXPORT_SYMBOL_GPL(vring_new_virtqueue);
|
|
|
|
void vring_del_virtqueue(struct virtqueue *_vq)
|
|
{
|
|
struct vring_virtqueue *vq = to_vvq(_vq);
|
|
|
|
if (vq->we_own_ring) {
|
|
vring_free_queue(vq->vq.vdev, vq->queue_size_in_bytes,
|
|
vq->vring.desc, vq->queue_dma_addr);
|
|
}
|
|
list_del(&_vq->list);
|
|
kfree(vq);
|
|
}
|
|
EXPORT_SYMBOL_GPL(vring_del_virtqueue);
|
|
|
|
/* Manipulates transport-specific feature bits. */
|
|
void vring_transport_features(struct virtio_device *vdev)
|
|
{
|
|
unsigned int i;
|
|
|
|
for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++) {
|
|
switch (i) {
|
|
case VIRTIO_RING_F_INDIRECT_DESC:
|
|
break;
|
|
case VIRTIO_RING_F_EVENT_IDX:
|
|
break;
|
|
case VIRTIO_F_VERSION_1:
|
|
break;
|
|
case VIRTIO_F_IOMMU_PLATFORM:
|
|
break;
|
|
default:
|
|
/* We don't understand this bit. */
|
|
__virtio_clear_bit(vdev, i);
|
|
}
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(vring_transport_features);
|
|
|
|
/**
|
|
* virtqueue_get_vring_size - return the size of the virtqueue's vring
|
|
* @vq: the struct virtqueue containing the vring of interest.
|
|
*
|
|
* Returns the size of the vring. This is mainly used for boasting to
|
|
* userspace. Unlike other operations, this need not be serialized.
|
|
*/
|
|
unsigned int virtqueue_get_vring_size(struct virtqueue *_vq)
|
|
{
|
|
|
|
struct vring_virtqueue *vq = to_vvq(_vq);
|
|
|
|
return vq->vring.num;
|
|
}
|
|
EXPORT_SYMBOL_GPL(virtqueue_get_vring_size);
|
|
|
|
bool virtqueue_is_broken(struct virtqueue *_vq)
|
|
{
|
|
struct vring_virtqueue *vq = to_vvq(_vq);
|
|
|
|
return vq->broken;
|
|
}
|
|
EXPORT_SYMBOL_GPL(virtqueue_is_broken);
|
|
|
|
/*
|
|
* This should prevent the device from being used, allowing drivers to
|
|
* recover. You may need to grab appropriate locks to flush.
|
|
*/
|
|
void virtio_break_device(struct virtio_device *dev)
|
|
{
|
|
struct virtqueue *_vq;
|
|
|
|
list_for_each_entry(_vq, &dev->vqs, list) {
|
|
struct vring_virtqueue *vq = to_vvq(_vq);
|
|
vq->broken = true;
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(virtio_break_device);
|
|
|
|
dma_addr_t virtqueue_get_desc_addr(struct virtqueue *_vq)
|
|
{
|
|
struct vring_virtqueue *vq = to_vvq(_vq);
|
|
|
|
BUG_ON(!vq->we_own_ring);
|
|
|
|
return vq->queue_dma_addr;
|
|
}
|
|
EXPORT_SYMBOL_GPL(virtqueue_get_desc_addr);
|
|
|
|
dma_addr_t virtqueue_get_avail_addr(struct virtqueue *_vq)
|
|
{
|
|
struct vring_virtqueue *vq = to_vvq(_vq);
|
|
|
|
BUG_ON(!vq->we_own_ring);
|
|
|
|
return vq->queue_dma_addr +
|
|
((char *)vq->vring.avail - (char *)vq->vring.desc);
|
|
}
|
|
EXPORT_SYMBOL_GPL(virtqueue_get_avail_addr);
|
|
|
|
dma_addr_t virtqueue_get_used_addr(struct virtqueue *_vq)
|
|
{
|
|
struct vring_virtqueue *vq = to_vvq(_vq);
|
|
|
|
BUG_ON(!vq->we_own_ring);
|
|
|
|
return vq->queue_dma_addr +
|
|
((char *)vq->vring.used - (char *)vq->vring.desc);
|
|
}
|
|
EXPORT_SYMBOL_GPL(virtqueue_get_used_addr);
|
|
|
|
const struct vring *virtqueue_get_vring(struct virtqueue *vq)
|
|
{
|
|
return &to_vvq(vq)->vring;
|
|
}
|
|
EXPORT_SYMBOL_GPL(virtqueue_get_vring);
|
|
|
|
MODULE_LICENSE("GPL");
|