mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 01:10:04 +00:00
![Daniel Vetter](/assets/img/avatar_default.png)
Now that my little helper has landed, use it more. On top of the existing check this also uses lockdep through the fs_reclaim annotations. Link: https://lkml.kernel.org/r/20210113135009.3606813-1-daniel.vetter@ffwll.ch Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
530 lines
14 KiB
C
530 lines
14 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* DMA Pool allocator
|
|
*
|
|
* Copyright 2001 David Brownell
|
|
* Copyright 2007 Intel Corporation
|
|
* Author: Matthew Wilcox <willy@linux.intel.com>
|
|
*
|
|
* This allocator returns small blocks of a given size which are DMA-able by
|
|
* the given device. It uses the dma_alloc_coherent page allocator to get
|
|
* new pages, then splits them up into blocks of the required size.
|
|
* Many older drivers still have their own code to do this.
|
|
*
|
|
* The current design of this allocator is fairly simple. The pool is
|
|
* represented by the 'struct dma_pool' which keeps a doubly-linked list of
|
|
* allocated pages. Each page in the page_list is split into blocks of at
|
|
* least 'size' bytes. Free blocks are tracked in an unsorted singly-linked
|
|
* list of free blocks within the page. Used blocks aren't tracked, but we
|
|
* keep a count of how many are currently allocated from each page.
|
|
*/
|
|
|
|
#include <linux/device.h>
|
|
#include <linux/dma-mapping.h>
|
|
#include <linux/dmapool.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/list.h>
|
|
#include <linux/export.h>
|
|
#include <linux/mutex.h>
|
|
#include <linux/poison.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/sched/mm.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/stat.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/string.h>
|
|
#include <linux/types.h>
|
|
#include <linux/wait.h>
|
|
|
|
#if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_SLUB_DEBUG_ON)
|
|
#define DMAPOOL_DEBUG 1
|
|
#endif
|
|
|
|
struct dma_pool { /* the pool */
|
|
struct list_head page_list;
|
|
spinlock_t lock;
|
|
size_t size;
|
|
struct device *dev;
|
|
size_t allocation;
|
|
size_t boundary;
|
|
char name[32];
|
|
struct list_head pools;
|
|
};
|
|
|
|
struct dma_page { /* cacheable header for 'allocation' bytes */
|
|
struct list_head page_list;
|
|
void *vaddr;
|
|
dma_addr_t dma;
|
|
unsigned int in_use;
|
|
unsigned int offset;
|
|
};
|
|
|
|
static DEFINE_MUTEX(pools_lock);
|
|
static DEFINE_MUTEX(pools_reg_lock);
|
|
|
|
static ssize_t
|
|
show_pools(struct device *dev, struct device_attribute *attr, char *buf)
|
|
{
|
|
unsigned temp;
|
|
unsigned size;
|
|
char *next;
|
|
struct dma_page *page;
|
|
struct dma_pool *pool;
|
|
|
|
next = buf;
|
|
size = PAGE_SIZE;
|
|
|
|
temp = scnprintf(next, size, "poolinfo - 0.1\n");
|
|
size -= temp;
|
|
next += temp;
|
|
|
|
mutex_lock(&pools_lock);
|
|
list_for_each_entry(pool, &dev->dma_pools, pools) {
|
|
unsigned pages = 0;
|
|
unsigned blocks = 0;
|
|
|
|
spin_lock_irq(&pool->lock);
|
|
list_for_each_entry(page, &pool->page_list, page_list) {
|
|
pages++;
|
|
blocks += page->in_use;
|
|
}
|
|
spin_unlock_irq(&pool->lock);
|
|
|
|
/* per-pool info, no real statistics yet */
|
|
temp = scnprintf(next, size, "%-16s %4u %4zu %4zu %2u\n",
|
|
pool->name, blocks,
|
|
pages * (pool->allocation / pool->size),
|
|
pool->size, pages);
|
|
size -= temp;
|
|
next += temp;
|
|
}
|
|
mutex_unlock(&pools_lock);
|
|
|
|
return PAGE_SIZE - size;
|
|
}
|
|
|
|
static DEVICE_ATTR(pools, 0444, show_pools, NULL);
|
|
|
|
/**
|
|
* dma_pool_create - Creates a pool of consistent memory blocks, for dma.
|
|
* @name: name of pool, for diagnostics
|
|
* @dev: device that will be doing the DMA
|
|
* @size: size of the blocks in this pool.
|
|
* @align: alignment requirement for blocks; must be a power of two
|
|
* @boundary: returned blocks won't cross this power of two boundary
|
|
* Context: not in_interrupt()
|
|
*
|
|
* Given one of these pools, dma_pool_alloc()
|
|
* may be used to allocate memory. Such memory will all have "consistent"
|
|
* DMA mappings, accessible by the device and its driver without using
|
|
* cache flushing primitives. The actual size of blocks allocated may be
|
|
* larger than requested because of alignment.
|
|
*
|
|
* If @boundary is nonzero, objects returned from dma_pool_alloc() won't
|
|
* cross that size boundary. This is useful for devices which have
|
|
* addressing restrictions on individual DMA transfers, such as not crossing
|
|
* boundaries of 4KBytes.
|
|
*
|
|
* Return: a dma allocation pool with the requested characteristics, or
|
|
* %NULL if one can't be created.
|
|
*/
|
|
struct dma_pool *dma_pool_create(const char *name, struct device *dev,
|
|
size_t size, size_t align, size_t boundary)
|
|
{
|
|
struct dma_pool *retval;
|
|
size_t allocation;
|
|
bool empty = false;
|
|
|
|
if (align == 0)
|
|
align = 1;
|
|
else if (align & (align - 1))
|
|
return NULL;
|
|
|
|
if (size == 0)
|
|
return NULL;
|
|
else if (size < 4)
|
|
size = 4;
|
|
|
|
size = ALIGN(size, align);
|
|
allocation = max_t(size_t, size, PAGE_SIZE);
|
|
|
|
if (!boundary)
|
|
boundary = allocation;
|
|
else if ((boundary < size) || (boundary & (boundary - 1)))
|
|
return NULL;
|
|
|
|
retval = kmalloc_node(sizeof(*retval), GFP_KERNEL, dev_to_node(dev));
|
|
if (!retval)
|
|
return retval;
|
|
|
|
strlcpy(retval->name, name, sizeof(retval->name));
|
|
|
|
retval->dev = dev;
|
|
|
|
INIT_LIST_HEAD(&retval->page_list);
|
|
spin_lock_init(&retval->lock);
|
|
retval->size = size;
|
|
retval->boundary = boundary;
|
|
retval->allocation = allocation;
|
|
|
|
INIT_LIST_HEAD(&retval->pools);
|
|
|
|
/*
|
|
* pools_lock ensures that the ->dma_pools list does not get corrupted.
|
|
* pools_reg_lock ensures that there is not a race between
|
|
* dma_pool_create() and dma_pool_destroy() or within dma_pool_create()
|
|
* when the first invocation of dma_pool_create() failed on
|
|
* device_create_file() and the second assumes that it has been done (I
|
|
* know it is a short window).
|
|
*/
|
|
mutex_lock(&pools_reg_lock);
|
|
mutex_lock(&pools_lock);
|
|
if (list_empty(&dev->dma_pools))
|
|
empty = true;
|
|
list_add(&retval->pools, &dev->dma_pools);
|
|
mutex_unlock(&pools_lock);
|
|
if (empty) {
|
|
int err;
|
|
|
|
err = device_create_file(dev, &dev_attr_pools);
|
|
if (err) {
|
|
mutex_lock(&pools_lock);
|
|
list_del(&retval->pools);
|
|
mutex_unlock(&pools_lock);
|
|
mutex_unlock(&pools_reg_lock);
|
|
kfree(retval);
|
|
return NULL;
|
|
}
|
|
}
|
|
mutex_unlock(&pools_reg_lock);
|
|
return retval;
|
|
}
|
|
EXPORT_SYMBOL(dma_pool_create);
|
|
|
|
static void pool_initialise_page(struct dma_pool *pool, struct dma_page *page)
|
|
{
|
|
unsigned int offset = 0;
|
|
unsigned int next_boundary = pool->boundary;
|
|
|
|
do {
|
|
unsigned int next = offset + pool->size;
|
|
if (unlikely((next + pool->size) >= next_boundary)) {
|
|
next = next_boundary;
|
|
next_boundary += pool->boundary;
|
|
}
|
|
*(int *)(page->vaddr + offset) = next;
|
|
offset = next;
|
|
} while (offset < pool->allocation);
|
|
}
|
|
|
|
static struct dma_page *pool_alloc_page(struct dma_pool *pool, gfp_t mem_flags)
|
|
{
|
|
struct dma_page *page;
|
|
|
|
page = kmalloc(sizeof(*page), mem_flags);
|
|
if (!page)
|
|
return NULL;
|
|
page->vaddr = dma_alloc_coherent(pool->dev, pool->allocation,
|
|
&page->dma, mem_flags);
|
|
if (page->vaddr) {
|
|
#ifdef DMAPOOL_DEBUG
|
|
memset(page->vaddr, POOL_POISON_FREED, pool->allocation);
|
|
#endif
|
|
pool_initialise_page(pool, page);
|
|
page->in_use = 0;
|
|
page->offset = 0;
|
|
} else {
|
|
kfree(page);
|
|
page = NULL;
|
|
}
|
|
return page;
|
|
}
|
|
|
|
static inline bool is_page_busy(struct dma_page *page)
|
|
{
|
|
return page->in_use != 0;
|
|
}
|
|
|
|
static void pool_free_page(struct dma_pool *pool, struct dma_page *page)
|
|
{
|
|
dma_addr_t dma = page->dma;
|
|
|
|
#ifdef DMAPOOL_DEBUG
|
|
memset(page->vaddr, POOL_POISON_FREED, pool->allocation);
|
|
#endif
|
|
dma_free_coherent(pool->dev, pool->allocation, page->vaddr, dma);
|
|
list_del(&page->page_list);
|
|
kfree(page);
|
|
}
|
|
|
|
/**
|
|
* dma_pool_destroy - destroys a pool of dma memory blocks.
|
|
* @pool: dma pool that will be destroyed
|
|
* Context: !in_interrupt()
|
|
*
|
|
* Caller guarantees that no more memory from the pool is in use,
|
|
* and that nothing will try to use the pool after this call.
|
|
*/
|
|
void dma_pool_destroy(struct dma_pool *pool)
|
|
{
|
|
struct dma_page *page, *tmp;
|
|
bool empty = false;
|
|
|
|
if (unlikely(!pool))
|
|
return;
|
|
|
|
mutex_lock(&pools_reg_lock);
|
|
mutex_lock(&pools_lock);
|
|
list_del(&pool->pools);
|
|
if (pool->dev && list_empty(&pool->dev->dma_pools))
|
|
empty = true;
|
|
mutex_unlock(&pools_lock);
|
|
if (empty)
|
|
device_remove_file(pool->dev, &dev_attr_pools);
|
|
mutex_unlock(&pools_reg_lock);
|
|
|
|
list_for_each_entry_safe(page, tmp, &pool->page_list, page_list) {
|
|
if (is_page_busy(page)) {
|
|
if (pool->dev)
|
|
dev_err(pool->dev, "%s %s, %p busy\n", __func__,
|
|
pool->name, page->vaddr);
|
|
else
|
|
pr_err("%s %s, %p busy\n", __func__,
|
|
pool->name, page->vaddr);
|
|
/* leak the still-in-use consistent memory */
|
|
list_del(&page->page_list);
|
|
kfree(page);
|
|
} else
|
|
pool_free_page(pool, page);
|
|
}
|
|
|
|
kfree(pool);
|
|
}
|
|
EXPORT_SYMBOL(dma_pool_destroy);
|
|
|
|
/**
|
|
* dma_pool_alloc - get a block of consistent memory
|
|
* @pool: dma pool that will produce the block
|
|
* @mem_flags: GFP_* bitmask
|
|
* @handle: pointer to dma address of block
|
|
*
|
|
* Return: the kernel virtual address of a currently unused block,
|
|
* and reports its dma address through the handle.
|
|
* If such a memory block can't be allocated, %NULL is returned.
|
|
*/
|
|
void *dma_pool_alloc(struct dma_pool *pool, gfp_t mem_flags,
|
|
dma_addr_t *handle)
|
|
{
|
|
unsigned long flags;
|
|
struct dma_page *page;
|
|
size_t offset;
|
|
void *retval;
|
|
|
|
might_alloc(mem_flags);
|
|
|
|
spin_lock_irqsave(&pool->lock, flags);
|
|
list_for_each_entry(page, &pool->page_list, page_list) {
|
|
if (page->offset < pool->allocation)
|
|
goto ready;
|
|
}
|
|
|
|
/* pool_alloc_page() might sleep, so temporarily drop &pool->lock */
|
|
spin_unlock_irqrestore(&pool->lock, flags);
|
|
|
|
page = pool_alloc_page(pool, mem_flags & (~__GFP_ZERO));
|
|
if (!page)
|
|
return NULL;
|
|
|
|
spin_lock_irqsave(&pool->lock, flags);
|
|
|
|
list_add(&page->page_list, &pool->page_list);
|
|
ready:
|
|
page->in_use++;
|
|
offset = page->offset;
|
|
page->offset = *(int *)(page->vaddr + offset);
|
|
retval = offset + page->vaddr;
|
|
*handle = offset + page->dma;
|
|
#ifdef DMAPOOL_DEBUG
|
|
{
|
|
int i;
|
|
u8 *data = retval;
|
|
/* page->offset is stored in first 4 bytes */
|
|
for (i = sizeof(page->offset); i < pool->size; i++) {
|
|
if (data[i] == POOL_POISON_FREED)
|
|
continue;
|
|
if (pool->dev)
|
|
dev_err(pool->dev, "%s %s, %p (corrupted)\n",
|
|
__func__, pool->name, retval);
|
|
else
|
|
pr_err("%s %s, %p (corrupted)\n",
|
|
__func__, pool->name, retval);
|
|
|
|
/*
|
|
* Dump the first 4 bytes even if they are not
|
|
* POOL_POISON_FREED
|
|
*/
|
|
print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 16, 1,
|
|
data, pool->size, 1);
|
|
break;
|
|
}
|
|
}
|
|
if (!(mem_flags & __GFP_ZERO))
|
|
memset(retval, POOL_POISON_ALLOCATED, pool->size);
|
|
#endif
|
|
spin_unlock_irqrestore(&pool->lock, flags);
|
|
|
|
if (want_init_on_alloc(mem_flags))
|
|
memset(retval, 0, pool->size);
|
|
|
|
return retval;
|
|
}
|
|
EXPORT_SYMBOL(dma_pool_alloc);
|
|
|
|
static struct dma_page *pool_find_page(struct dma_pool *pool, dma_addr_t dma)
|
|
{
|
|
struct dma_page *page;
|
|
|
|
list_for_each_entry(page, &pool->page_list, page_list) {
|
|
if (dma < page->dma)
|
|
continue;
|
|
if ((dma - page->dma) < pool->allocation)
|
|
return page;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/**
|
|
* dma_pool_free - put block back into dma pool
|
|
* @pool: the dma pool holding the block
|
|
* @vaddr: virtual address of block
|
|
* @dma: dma address of block
|
|
*
|
|
* Caller promises neither device nor driver will again touch this block
|
|
* unless it is first re-allocated.
|
|
*/
|
|
void dma_pool_free(struct dma_pool *pool, void *vaddr, dma_addr_t dma)
|
|
{
|
|
struct dma_page *page;
|
|
unsigned long flags;
|
|
unsigned int offset;
|
|
|
|
spin_lock_irqsave(&pool->lock, flags);
|
|
page = pool_find_page(pool, dma);
|
|
if (!page) {
|
|
spin_unlock_irqrestore(&pool->lock, flags);
|
|
if (pool->dev)
|
|
dev_err(pool->dev, "%s %s, %p/%pad (bad dma)\n",
|
|
__func__, pool->name, vaddr, &dma);
|
|
else
|
|
pr_err("%s %s, %p/%pad (bad dma)\n",
|
|
__func__, pool->name, vaddr, &dma);
|
|
return;
|
|
}
|
|
|
|
offset = vaddr - page->vaddr;
|
|
if (want_init_on_free())
|
|
memset(vaddr, 0, pool->size);
|
|
#ifdef DMAPOOL_DEBUG
|
|
if ((dma - page->dma) != offset) {
|
|
spin_unlock_irqrestore(&pool->lock, flags);
|
|
if (pool->dev)
|
|
dev_err(pool->dev, "%s %s, %p (bad vaddr)/%pad\n",
|
|
__func__, pool->name, vaddr, &dma);
|
|
else
|
|
pr_err("%s %s, %p (bad vaddr)/%pad\n",
|
|
__func__, pool->name, vaddr, &dma);
|
|
return;
|
|
}
|
|
{
|
|
unsigned int chain = page->offset;
|
|
while (chain < pool->allocation) {
|
|
if (chain != offset) {
|
|
chain = *(int *)(page->vaddr + chain);
|
|
continue;
|
|
}
|
|
spin_unlock_irqrestore(&pool->lock, flags);
|
|
if (pool->dev)
|
|
dev_err(pool->dev, "%s %s, dma %pad already free\n",
|
|
__func__, pool->name, &dma);
|
|
else
|
|
pr_err("%s %s, dma %pad already free\n",
|
|
__func__, pool->name, &dma);
|
|
return;
|
|
}
|
|
}
|
|
memset(vaddr, POOL_POISON_FREED, pool->size);
|
|
#endif
|
|
|
|
page->in_use--;
|
|
*(int *)vaddr = page->offset;
|
|
page->offset = offset;
|
|
/*
|
|
* Resist a temptation to do
|
|
* if (!is_page_busy(page)) pool_free_page(pool, page);
|
|
* Better have a few empty pages hang around.
|
|
*/
|
|
spin_unlock_irqrestore(&pool->lock, flags);
|
|
}
|
|
EXPORT_SYMBOL(dma_pool_free);
|
|
|
|
/*
|
|
* Managed DMA pool
|
|
*/
|
|
static void dmam_pool_release(struct device *dev, void *res)
|
|
{
|
|
struct dma_pool *pool = *(struct dma_pool **)res;
|
|
|
|
dma_pool_destroy(pool);
|
|
}
|
|
|
|
static int dmam_pool_match(struct device *dev, void *res, void *match_data)
|
|
{
|
|
return *(struct dma_pool **)res == match_data;
|
|
}
|
|
|
|
/**
|
|
* dmam_pool_create - Managed dma_pool_create()
|
|
* @name: name of pool, for diagnostics
|
|
* @dev: device that will be doing the DMA
|
|
* @size: size of the blocks in this pool.
|
|
* @align: alignment requirement for blocks; must be a power of two
|
|
* @allocation: returned blocks won't cross this boundary (or zero)
|
|
*
|
|
* Managed dma_pool_create(). DMA pool created with this function is
|
|
* automatically destroyed on driver detach.
|
|
*
|
|
* Return: a managed dma allocation pool with the requested
|
|
* characteristics, or %NULL if one can't be created.
|
|
*/
|
|
struct dma_pool *dmam_pool_create(const char *name, struct device *dev,
|
|
size_t size, size_t align, size_t allocation)
|
|
{
|
|
struct dma_pool **ptr, *pool;
|
|
|
|
ptr = devres_alloc(dmam_pool_release, sizeof(*ptr), GFP_KERNEL);
|
|
if (!ptr)
|
|
return NULL;
|
|
|
|
pool = *ptr = dma_pool_create(name, dev, size, align, allocation);
|
|
if (pool)
|
|
devres_add(dev, ptr);
|
|
else
|
|
devres_free(ptr);
|
|
|
|
return pool;
|
|
}
|
|
EXPORT_SYMBOL(dmam_pool_create);
|
|
|
|
/**
|
|
* dmam_pool_destroy - Managed dma_pool_destroy()
|
|
* @pool: dma pool that will be destroyed
|
|
*
|
|
* Managed dma_pool_destroy().
|
|
*/
|
|
void dmam_pool_destroy(struct dma_pool *pool)
|
|
{
|
|
struct device *dev = pool->dev;
|
|
|
|
WARN_ON(devres_release(dev, dmam_pool_release, dmam_pool_match, pool));
|
|
}
|
|
EXPORT_SYMBOL(dmam_pool_destroy);
|