/*
* Copyright 2011 (c) Oracle Corp.
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sub license,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial portions
* of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*
* Author: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
*/
/*
* A simple DMA pool losely based on dmapool.c. It has certain advantages
* over the DMA pools:
* - Pool collects resently freed pages for reuse (and hooks up to
* the shrinker).
* - Tracks currently in use pages
* - Tracks whether the page is UC, WB or cached (and reverts to WB
* when freed).
*/
#define pr_fmt(fmt) "[TTM] " fmt
#include <linux/dma-mapping.h>
#include <linux/list.h>
#include <linux/seq_file.h> /* for seq_printf */
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/highmem.h>
#include <linux/mm_types.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/atomic.h>
#include <linux/device.h>
#include <linux/kthread.h>
#include <drm/ttm/ttm_bo_driver.h>
#include <drm/ttm/ttm_page_alloc.h>
#ifdef TTM_HAS_AGP
#include <asm/agp.h>
#endif
#define NUM_PAGES_TO_ALLOC (PAGE_SIZE/sizeof(struct page *))
#define SMALL_ALLOCATION 4
#define FREE_ALL_PAGES (~0U)
/* times are in msecs */
#define IS_UNDEFINED (0)
#define IS_WC (1<<1)
#define IS_UC (1<<2)
#define IS_CACHED (1<<3)
#define IS_DMA32 (1<<4)
enum pool_type {
POOL_IS_UNDEFINED,
POOL_IS_WC = IS_WC,
POOL_IS_UC = IS_UC,
POOL_IS_CACHED = IS_CACHED,
POOL_IS_WC_DMA32 = IS_WC | IS_DMA32,
POOL_IS_UC_DMA32 = IS_UC | IS_DMA32,
POOL_IS_CACHED_DMA32 = IS_CACHED | IS_DMA32,
};
/*
* The pool structure. There are usually six pools:
* - generic (not restricted to DMA32):
* - write combined, uncached, cached.
* - dma32 (up to 2^32 - so up 4GB):
* - write combined, uncached, cached.
* for each 'struct device'. The 'cached' is for pages that are actively used.
* The other ones can be shrunk by the shrinker API if neccessary.
* @pools: The 'struct device->dma_pools' link.
* @type: Type of the pool
* @lock: Protects the inuse_list and free_list from concurrnet access. Must be
* used with irqsave/irqrestore variants because pool allocator maybe called
* from delayed work.
* @inuse_list: Pool of pages that are in use. The order is very important and
* it is in the order that the TTM pages that are put back are in.
* @free_list: Pool of pages that are free to be used. No order requirements.
* @dev: The device that is associated with these pools.
* @size: Size used during DMA allocation.
* @npages_free: Count of available pages for re-use.
* @npages_in_use: Count of pages that are in use.
* @nfrees: Stats when pool is shrinking.
* @nrefills: Stats when the pool is grown.
* @gfp_flags: Flags to pass for alloc_page.
* @name: Name of the pool.
* @dev_name: Name derieved from dev - similar to how dev_info works.
* Used during shutdown as the dev_info during release is unavailable.
*/
struct dma_pool {
struct list_head pools; /* The 'struct device->dma_pools link */
enum pool_type type;
spinlock_t lock;
struct list_head inuse_list;
struct list_head free_list;
struct device *dev;
unsigned size;
unsigned npages_free;
unsigned npages_in_use;
unsigned long nfrees; /* Stats when shrunk. */
unsigned long nrefills; /* Stats when grown. */
gfp_t gfp_flags;
char name[13]; /* "cached dma32" */
char dev_name[64]; /* Constructed from dev */
};
/*
* The accounting page keeping track of the allocated page along with
* the DMA address.
* @page_list: The link to the 'page_list' in 'struct dma_pool'.
* @vaddr: The virtual address of the page
* @dma: The bus address of the page. If the page is not allocated
* via the DMA API, it will be -1.
*/
struct dma_page {
struct list_head page_list;
void *vaddr;
struct page *p;
dma_addr_t dma;
};
/*
* Limits for the pool. They are handled without locks because only place where
* they may change is in sysfs store. They won't have immediate effect anyway
* so forcing serialization to access them is pointless.
*/
struct ttm_pool_opts {
unsigned alloc_size;
unsigned max_size;
unsigned small;
};
/*
* Contains the list of all of the 'struct device' and their corresponding
* DMA pools. Guarded by _mutex->lock.
* @pools: The link to 'struct ttm_pool_manager->pools'
* @dev: The 'struct device' associated with the 'pool'
* @pool: The 'struct dma_pool' associated with the 'dev'
*/
struct device_pools {
struct list_head pools;
struct device *dev;
struct dma_pool *pool;
};
/*
* struct ttm_pool_manager - Holds memory pools for fast allocation
*
* @lock: Lock used when adding/removing from pools
* @pools: List of 'struct device' and 'struct dma_pool' tuples.
* @options: Limits for the pool.
* @npools: Total amount of pools in existence.
* @shrinker: The structure used by [un|]register_shrinker
*/
struct ttm_pool_manager {
struct mutex lock;
struct list_head pools;
struct ttm_pool_opts options;
unsigned npools;
struct shrinker mm_shrink;
struct kobject kobj;
};
static struct ttm_pool_manager *_manager;
static struct attribute ttm_page_pool_max = {
.name = "pool_max_size",
.mode = S_IRUGO | S_IWUSR
};
static struct attribute ttm_page_pool_small = {
.name = "pool_small_allocation",
.mode = S_IRUGO | S_IWUSR
};
static struct attribute ttm_page_pool_alloc_size = {
.name = "pool_allocation_size",
.mode = S_IRUGO | S_IWUSR
};
static struct attribute *ttm_pool_attrs[] = {
&ttm_page_pool_max,
&ttm_page_pool_small,
&ttm_page_pool_alloc_size,
NULL
};
static void ttm_pool_kobj_release(struct kobject *kobj)
{
struct ttm_pool_manager *m =
container_of(kobj, struct ttm_pool_manager, kobj);
kfree(m);
}
static ssize_t ttm_pool_store(struct kobject *kobj, struct attribute *attr,
const char *buffer, size_t size)
{
struct ttm_pool_manager *m =
container_of(kobj, struct ttm_pool_manager, kobj);
int chars;
unsigned val;
chars = sscanf(buffer, "%u", &val);
if (chars == 0)
return size;
/* Convert kb to number of pages */
val = val / (PAGE_SIZE >> 10);
if (attr == &ttm_page_pool_max)
m->options.max_size = val;
else if (attr == &ttm_page_pool_small)
m->options.small = val;
else if (attr == &ttm_page_pool_alloc_size) {
if (val > NUM_PAGES_TO_ALLOC*8) {
pr_err("Setting allocation size to %lu is not allowed. Recommended size is %lu\n",
NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 7),
NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
return size;
} else if (val > NUM_PAGES_TO_ALLOC) {
pr_warn("Setting allocation size to larger than %lu is not recommended\n",
NUM_PAGES_TO_ALLOC*(PAGE_SIZE >> 10));
}
m->options.alloc_size = val;
}
return size;
}
static ssize_t ttm_pool_show(struct kobject *kobj, struct attribute *attr,
char *buffer)
{
struct ttm_pool_manager *m =
container_of(kobj, struct ttm_pool_manager, kobj);
unsigned val = 0;
if (attr == &ttm_page_pool_max)
val = m->options.max_size;
else if (attr == &ttm_page_pool_small)
val = m->options.small;
else if (attr == &ttm_page_pool_alloc_size)
val = m->options.alloc_size;
val = val * (PAGE_SIZE >> 10);
return snprintf(buffer, PAGE_SIZE, "%u\n", val);
}
static const struct sysfs_ops ttm_pool_sysfs_ops = {
.show = &ttm_pool_show,
.store = &ttm_pool_store,
};
static struct kobj_type ttm_pool_kobj_type = {
.release = &ttm_pool_kobj_release,
.sysfs_ops = &ttm_pool_sysfs_ops,
.default_attrs = ttm_pool_attrs,
};
#ifndef CONFIG_X86
static int set_pages_array_wb(struct page **pages, int addrinarray)
{
#ifdef TTM_HAS_AGP
int i;
for (i = 0; i < addrinarray; i++)
unmap_page_from_agp(pages[i]);
#endif
return 0;
}
static int set_pages_array_wc(struct page **pages, int addrinarray)
{
#ifdef TTM_HAS_AGP
int i;
for (i = 0; i < addrinarray; i++)
map_page_into_agp(pages[i]);
#endif
return 0;
}
static int set_pages_array_uc(struct page **pages, int addrinarray)
{
#ifdef TTM_HAS_AGP
int i;
for (i = 0; i < addrinarray; i++)
map_page_into_agp(pages[i]);
#endif
return 0;
}
#endif /* for !CONFIG_X86 */
static int ttm_set_pages_caching(struct dma_pool *pool,
struct page **pages, unsigned cpages)
{
int r = 0;
/* Set page caching */
if (pool->type & IS_UC) {
r = set_pages_array_uc(pages, cpages);
if (r)
pr_err("%s: Failed to set %d pages to uc!\n",
pool->dev_name, cpages);
}
if (pool->type & IS_WC) {
r = set_pages_array_wc(pages, cpages);
if (r)
pr_err("%s: Failed to set %d pages to wc!\n",
pool->dev_name, cpages);
}
return r;
}
static void __ttm_dma_free_page(struct dma_pool *pool, struct dma_page *d_page)
{
dma_addr_t dma = d_page->dma;
dma_free_coherent(pool->dev, pool->size, d_page->vaddr, dma);
kfree(d_page);
d_page = NULL;
}
static struct dma_page *__ttm_dma_alloc_page(struct dma_pool *pool)
{
struct dma_page *d_page;
d_page = kmalloc(sizeof(struct dma_page), GFP_KERNEL);
if (!d_page)
return NULL;
d_page->vaddr = dma_alloc_coherent(pool->dev, pool->size,
&d_page->dma,
pool->gfp_flags);
if (d_page->vaddr)
d_page->p = virt_to_page(d_page->vaddr);
else {
kfree(d_page);
d_page = NULL;
}
return d_page;
}
static enum pool_type ttm_to_type(int flags, enum ttm_caching_state cstate)
{
enum pool_type type = IS_UNDEFINED;
if (flags & TTM_PAGE_FLAG_DMA32)
type |= IS_DMA32;
if (cstate == tt_cached)
type |= IS_CACHED;
else if (cstate == tt_uncached)
type |= IS_UC;
else
type |= IS_WC;
return type;
}
static void ttm_pool_update_free_locked(struct dma_pool *pool,
unsigned freed_pages)
{
pool->npages_free -= freed_pages;
pool->nfrees += freed_pages;
}
/* set memory back to wb and free the pages. */
static void ttm_dma_pages_put(struct dma_pool *pool, struct list_head *d_pages,
struct page *pages[], unsigned npages)
{
struct dma_page *d_page, *tmp;
/* Don't set WB on WB page pool. */
if (npages && !(pool->type & IS_CACHED) &&
set_pages_array_wb(pages, npages))
pr_err("%s: Failed to set %d pages to wb!\n",
pool->dev_name, npages);
list_for_each_entry_safe(d_page, tmp, d_pages, page_list) {
list_del(&d_page->page_list);
__ttm_dma_free_page(pool, d_page);
}
}
static void ttm_dma_page_put(struct dma_pool *pool, struct dma_page *d_page)
{
/* Don't set WB on WB page pool. */
if (!(pool->type & IS_CACHED) && set_pages_array_wb(&d_page->p, 1))
pr_err("%s: Failed to set %d pages to wb!\n",
pool->dev_name, 1);
list_del(&d_page->page_list);
__ttm_dma_free_page(pool, d_page);
}
/*
* Free pages from pool.
*
* To prevent hogging the ttm_swap process we only free NUM_PAGES_TO_ALLOC
* number of pages in one go.
*
* @pool: to free the pages from
* @nr_free: If set to true will free all pages in pool
**/
static unsigned ttm_dma_page_pool_free(struct dma_pool *pool, unsigned nr_free)
{
unsigned long irq_flags;
struct dma_page *dma_p, *tmp;
struct page **pages_to_free;
struct list_head d_pages;
unsigned freed_pages = 0,
npages_to_free = nr_free;
if (NUM_PAGES_TO_ALLOC < nr_free)
npages_to_free = NUM_PAGES_TO_ALLOC;
#if 0
if (nr_free > 1) {
pr_debug("%s: (%s:%d) Attempting to free %d (%d) pages\n",
pool->dev_name, pool->name, current->pid,
npages_to_free, nr_free);
}
#endif
pages_to_free = kmalloc(npages_to_free * sizeof(struct page *),
GFP_KERNEL);
if (!pages_to_free) {
pr_err("%s: Failed to allocate memory for pool free operation\n",
pool->dev_name);
return 0;
}
INIT_LIST_HEAD(&d_pages);
restart:
spin_lock_irqsave(&pool->lock, irq_flags);
/* We picking the oldest ones off the list */
list_for_each_entry_safe_reverse(dma_p, tmp, &pool->free_list,
page_list) {
if (freed_pages >= npages_to_free)
break;
/* Move the dma_page from one list to another. */
list_move(&dma_p->page_list, &d_pages);
pages_to_free[freed_pages++] = dma_p->p;
/* We can only remove NUM_PAGES_TO_ALLOC at a time. */
if (freed_pages >= NUM_PAGES_TO_ALLOC) {
ttm_pool_update_free_locked(pool, freed_pages);
/**
* Because changing page caching is costly
* we unlock the pool to prevent stalling.
*/
spin_unlock_irqrestore(&pool->lock, irq_flags);
ttm_dma_pages_put(pool, &d_pages, pages_to_free,
freed_pages);
INIT_LIST_HEAD(&d_pages);
if (likely(nr_free != FREE_ALL_PAGES))
nr_free -= freed_pages;
if (NUM_PAGES_TO_ALLOC >= nr_free)
npages_to_free = nr_free;
else
npages_to_free = NUM_PAGES_TO_ALLOC;
freed_pages = 0;
/* free all so restart the processing */
if (nr_free)
goto restart;
/* Not allowed to fall through or break because
* following context is inside spinlock while we are
* outside here.
*/
goto out;
}
}
/* remove range of pages from the pool */
if (freed_pages) {
ttm_pool_update_free_locked(pool, freed_pages);
nr_free -= freed_pages;
}
spin_unlock_irqrestore(&pool->lock, irq_flags);
if (freed_pages)
ttm_dma_pages_put(pool, &d_pages, pages_to_free, freed_pages);
out:
kfree(pages_to_free);
return nr_free;
}
static void ttm_dma_free_pool(struct device *dev, enum pool_type type)
{
struct device_pools *p;
struct dma_pool *pool;
if (!dev)
return;
mutex_lock(&_manager->lock);
list_for_each_entry_reverse(p, &_manager->pools, pools) {
if (p->dev != dev)
continue;
pool = p->pool;
if (pool->type != type)
continue;
list_del(&p->pools);
kfree(p);
_manager->npools--;
break;
}
list_for_each_entry_reverse(pool, &dev->dma_pools, pools) {
if (pool->type != type)
continue;
/* Takes a spinlock.. */
ttm_dma_page_pool_free(pool, FREE_ALL_PAGES);
WARN_ON(((pool->npages_in_use + pool->npages_free) != 0));
/* This code path is called after _all_ references to the
* struct device has been dropped - so nobody should be
* touching it. In case somebody is trying to _add_ we are
* guarded by the mutex. */
list_del(&pool->pools);
kfree(pool);
break;
}
mutex_unlock(&_manager->lock);
}
/*
* On free-ing of the 'struct device' this deconstructor is run.
* Albeit the pool might have already been freed earlier.
*/
static void ttm_dma_pool_release(struct device *dev, void *res)
{
struct dma_pool *pool = *(struct dma_pool **)res;
if (pool)
ttm_dma_free_pool(dev, pool->type);
}
static int ttm_dma_pool_match(struct device *dev, void *res, void *match_data)
{
return *(struct dma_pool **)res == match_data;
}
static struct dma_pool *ttm_dma_pool_init(struct device *dev, gfp_t flags,
enum pool_type type)
{
char *n[] = {"wc", "uc", "cached", " dma32", "unknown",};
enum pool_type t[] = {IS_WC, IS_UC, IS_CACHED, IS_DMA32, IS_UNDEFINED};
struct device_pools *sec_pool = NULL;
struct dma_pool *pool = NULL, **ptr;
unsigned i;
int ret = -ENODEV;
char *p;
if (!dev)
return NULL;
ptr = devres_alloc(ttm_dma_pool_release, sizeof(*ptr), GFP_KERNEL);
if (!ptr)
return NULL;
ret = -ENOMEM;
pool = kmalloc_node(sizeof(struct dma_pool), GFP_KERNEL,
dev_to_node(dev));
if (!pool)
goto err_mem;
sec_pool = kmalloc_node(sizeof(struct device_pools), GFP_KERNEL,
dev_to_node(dev));
if (!sec_pool)
goto err_mem;
INIT_LIST_HEAD(&sec_pool->pools);
sec_pool->dev = dev;
sec_pool->pool = pool;
INIT_LIST_HEAD(&pool->free_list);
INIT_LIST_HEAD(&pool->inuse_list);
INIT_LIST_HEAD(&pool->pools);
spin_lock_init(&pool->lock);
pool->dev = dev;
pool->npages_free = pool->npages_in_use = 0;
pool->nfrees = 0;
pool->gfp_flags = flags;
pool->size = PAGE_SIZE;
pool->type = type;
pool->nrefills = 0;
p = pool->name;
for (i = 0; i < 5; i++) {
if (type & t[i]) {
p += snprintf(p, sizeof(pool->name) - (p - pool->name),
"%s", n[i]);
}
}
*p = 0;
/* We copy the name for pr_ calls b/c when dma_pool_destroy is called
* - the kobj->name has already been deallocated.*/
snprintf(pool->dev_name, sizeof(pool->dev_name), "%s %s",
dev_driver_string(dev), dev_name(dev));
mutex_lock(&_manager->lock);
/* You can get the dma_pool from either the global: */
list_add(&sec_pool->pools, &_manager->pools);
_manager->npools++;
/* or from 'struct device': */
list_add(&pool->pools, &dev->dma_pools);
mutex_unlock(&_manager->lock);
*ptr = pool;
devres_add(dev, ptr);
return pool;
err_mem:
devres_free(ptr);
kfree(sec_pool);
kfree(pool);
return ERR_PTR(ret);
}
static struct dma_pool *ttm_dma_find_pool(struct device *dev,
enum pool_type type)
{
struct dma_pool *pool, *tmp, *found = NULL;
if (type == IS_UNDEFINED)
return found;
/* NB: We iterate on the 'struct dev' which has no spinlock, but
* it does have a kref which we have taken. The kref is taken during
* graphic driver loading - in the drm_pci_init it calls either
* pci_dev_get or pci_register_driver which both end up taking a kref
* on 'struct device'.
*
* On teardown, the graphic drivers end up quiescing the TTM (put_pages)
* and calls the dev_res deconstructors: ttm_dma_pool_release. The nice
* thing is at that point of time there are no pages associated with the
* driver so this function will not be called.
*/
list_for_each_entry_safe(pool, tmp, &dev->dma_pools, pools) {
if (pool->type != type)
continue;
found = pool;
break;
}
return found;
}
/*
* Free pages the pages that failed to change the caching state. If there
* are pages that have changed their caching state already put them to the
* pool.
*/
static void ttm_dma_handle_caching_state_failure(struct dma_pool *pool,
struct list_head *d_pages,
struct page **failed_pages,
unsigned cpages)
{
struct dma_page *d_page, *tmp;
struct page *p;
unsigned i = 0;
p = failed_pages[0];
if (!p)
return;
/* Find the failed page. */
list_for_each_entry_safe(d_page, tmp, d_pages, page_list) {
if (d_page->p != p)
continue;
/* .. and then progress over the full list. */
list_del(&d_page->page_list);
__ttm_dma_free_page(pool, d_page);
if (++i < cpages)
p = failed_pages[i];
else
break;
}
}
/*
* Allocate 'count' pages, and put 'need' number of them on the
* 'pages' and as well on the 'dma_address' starting at 'dma_offset' offset.
* The full list of pages should also be on 'd_pages'.
* We return zero for success, and negative numbers as errors.
*/
static int ttm_dma_pool_alloc_new_pages(struct dma_pool *pool,
struct list_head *d_pages,
unsigned count)
{
struct page **caching_array;
struct dma_page *dma_p;
struct page *p;
int r = 0;
unsigned i, cpages;
unsigned max_cpages = min(count,
(unsigned)(PAGE_SIZE/sizeof(struct page *)));
/* allocate array for page caching change */
caching_array = kmalloc(max_cpages*sizeof(struct page *), GFP_KERNEL);
if (!caching_array) {
pr_err("%s: Unable to allocate table for new pages\n",
pool->dev_name);
return -ENOMEM;
}
if (count > 1) {
pr_debug("%s: (%s:%d) Getting %d pages\n",
pool->dev_name, pool->name, current->pid, count);
}
for (i = 0, cpages = 0; i < count; ++i) {
dma_p = __ttm_dma_alloc_page(pool);
if (!dma_p) {
pr_err("%s: Unable to get page %u\n",
pool->dev_name, i);
/* store already allocated pages in the pool after
* setting the caching state */
if (cpages) {
r = ttm_set_pages_caching(pool, caching_array,
cpages);
if (r)
ttm_dma_handle_caching_state_failure(
pool, d_pages, caching_array,
cpages);
}
r = -ENOMEM;
goto out;
}
p = dma_p->p;
#ifdef CONFIG_HIGHMEM
/* gfp flags of highmem page should never be dma32 so we
* we should be fine in such case
*/
if (!PageHighMem(p))
#endif
{
caching_array[cpages++] = p;
if (cpages == max_cpages) {
/* Note: Cannot hold the spinlock */
r = ttm_set_pages_caching(pool, caching_array,
cpages);
if (r) {
ttm_dma_handle_caching_state_failure(
pool, d_pages, caching_array,
cpages);
goto out;
}
cpages = 0;
}
}
list_add(&dma_p->page_list, d_pages);
}
if (cpages) {
r = ttm_set_pages_caching(pool, caching_array, cpages);
if (r)
ttm_dma_handle_caching_state_failure(pool, d_pages,
caching_array, cpages);
}
out:
kfree(caching_array);
return r;
}
/*
* @return count of pages still required to fulfill the request.
*/
static int ttm_dma_page_pool_fill_locked(struct dma_pool *pool,
unsigned long *irq_flags)
{
unsigned count = _manager->options.small;
int r = pool->npages_free;
if (count > pool->npages_free) {
struct list_head d_pages;
INIT_LIST_HEAD(&d_pages);
spin_unlock_irqrestore(&pool->lock, *irq_flags);
/* Returns how many more are neccessary to fulfill the
* request. */
r = ttm_dma_pool_alloc_new_pages(pool, &d_pages, count);
spin_lock_irqsave(&pool->lock, *irq_flags);
if (!r) {
/* Add the fresh to the end.. */
list_splice(&d_pages, &pool->free_list);
++pool->nrefills;
pool->npages_free += count;
r = count;
} else {
struct dma_page *d_page;
unsigned cpages = 0;
pr_err("%s: Failed to fill %s pool (r:%d)!\n",
pool->dev_name, pool->name, r);
list_for_each_entry(d_page, &d_pages, page_list) {
cpages++;
}
list_splice_tail(&d_pages, &pool->free_list);
pool->npages_free += cpages;
r = cpages;
}
}
return r;
}
/*
* @return count of pages still required to fulfill the request.
* The populate list is actually a stack (not that is matters as TTM
* allocates one page at a time.
*/
static int ttm_dma_pool_get_pages(struct dma_pool *pool,
struct ttm_dma_tt *ttm_dma,
unsigned index)
{
struct dma_page *d_page;
struct ttm_tt *ttm = &ttm_dma->ttm;
unsigned long irq_flags;
int count, r = -ENOMEM;
spin_lock_irqsave(&pool->lock, irq_flags);
count = ttm_dma_page_pool_fill_locked(pool, &irq_flags);
if (count) {
d_page = list_first_entry(&pool->free_list, struct dma_page, page_list);
ttm->pages[index] = d_page->p;
ttm_dma->dma_address[index] = d_page->dma;
list_move_tail(&d_page->page_list, &ttm_dma->pages_list);
r = 0;
pool->npages_in_use += 1;
pool->npages_free -= 1;
}
spin_unlock_irqrestore(&pool->lock, irq_flags);
return r;
}
/*
* On success pages list will hold count number of correctly
* cached pages. On failure will hold the negative return value (-ENOMEM, etc).
*/
int ttm_dma_populate(struct ttm_dma_tt *ttm_dma, struct device *dev)
{
struct ttm_tt *ttm = &ttm_dma->ttm;
struct ttm_mem_global *mem_glob = ttm->glob->mem_glob;
struct dma_pool *pool;
enum pool_type type;
unsigned i;
gfp_t gfp_flags;
int ret;
if (ttm->state != tt_unpopulated)
return 0;
type = ttm_to_type(ttm->page_flags, ttm->caching_state);
if (ttm->page_flags & TTM_PAGE_FLAG_DMA32)
gfp_flags = GFP_USER | GFP_DMA32;
else
gfp_flags = GFP_HIGHUSER;
if (ttm->page_flags & TTM_PAGE_FLAG_ZERO_ALLOC)
gfp_flags |= __GFP_ZERO;
pool = ttm_dma_find_pool(dev, type);
if (!pool) {
pool = ttm_dma_pool_init(dev, gfp_flags, type);
if (IS_ERR_OR_NULL(pool)) {
return -ENOMEM;
}
}
INIT_LIST_HEAD(&ttm_dma->pages_list);
for (i = 0; i < ttm->num_pages; ++i) {
ret = ttm_dma_pool_get_pages(pool, ttm_dma, i);
if (ret != 0) {
ttm_dma_unpopulate(ttm_dma, dev);
return -ENOMEM;
}
ret = ttm_mem_global_alloc_page(mem_glob, ttm->pages[i],
false, false);
if (unlikely(ret != 0)) {
ttm_dma_unpopulate(ttm_dma, dev);
return -ENOMEM;
}
}
if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
ret = ttm_tt_swapin(ttm);
if (unlikely(ret != 0)) {
ttm_dma_unpopulate(ttm_dma, dev);
return ret;
}
}
ttm->state = tt_unbound;
return 0;
}
EXPORT_SYMBOL_GPL(ttm_dma_populate);
/* Get good estimation how many pages are free in pools */
static int ttm_dma_pool_get_num_unused_pages(void)
{
struct device_pools *p;
unsigned total = 0;
mutex_lock(&_manager->lock);
list_for_each_entry(p, &_manager->pools, pools)
total += p->pool->npages_free;
mutex_unlock(&_manager->lock);
return total;
}
/* Put all pages in pages list to correct pool to wait for reuse */
void ttm_dma_unpopulate(struct ttm_dma_tt *ttm_dma, struct device *dev)
{
struct ttm_tt *ttm = &ttm_dma->ttm;
struct dma_pool *pool;
struct dma_page *d_page, *next;
enum pool_type type;
bool is_cached = false;
unsigned count = 0, i, npages = 0;
unsigned long irq_flags;
type = ttm_to_type(ttm->page_flags, ttm->caching_state);
pool = ttm_dma_find_pool(dev, type);
if (!pool)
return;
is_cached = (ttm_dma_find_pool(pool->dev,
ttm_to_type(ttm->page_flags, tt_cached)) == pool);
/* make sure pages array match list and count number of pages */
list_for_each_entry(d_page, &ttm_dma->pages_list, page_list) {
ttm->pages[count] = d_page->p;
count++;
}
spin_lock_irqsave(&pool->lock, irq_flags);
pool->npages_in_use -= count;
if (is_cached) {
pool->nfrees += count;
} else {
pool->npages_free += count;
list_splice(&ttm_dma->pages_list, &pool->free_list);
npages = count;
if (pool->npages_free > _manager->options.max_size) {
npages = pool->npages_free - _manager->options.max_size;
/* free at least NUM_PAGES_TO_ALLOC number of pages
* to reduce calls to set_memory_wb */
if (npages < NUM_PAGES_TO_ALLOC)
npages = NUM_PAGES_TO_ALLOC;
}
}
spin_unlock_irqrestore(&pool->lock, irq_flags);
if (is_cached) {
list_for_each_entry_safe(d_page, next, &ttm_dma->pages_list, page_list) {
ttm_mem_global_free_page(ttm->glob->mem_glob,
d_page->p);
ttm_dma_page_put(pool, d_page);
}
} else {
for (i = 0; i < count; i++) {
ttm_mem_global_free_page(ttm->glob->mem_glob,
ttm->pages[i]);
}
}
INIT_LIST_HEAD(&ttm_dma->pages_list);
for (i = 0; i < ttm->num_pages; i++) {
ttm->pages[i] = NULL;
ttm_dma->dma_address[i] = 0;
}
/* shrink pool if necessary (only on !is_cached pools)*/
if (npages)
ttm_dma_page_pool_free(pool, npages);
ttm->state = tt_unpopulated;
}
EXPORT_SYMBOL_GPL(ttm_dma_unpopulate);
/**
* Callback for mm to request pool to reduce number of page held.
*/
static int ttm_dma_pool_mm_shrink(struct shrinker *shrink,
struct shrink_control *sc)
{
static atomic_t start_pool = ATOMIC_INIT(0);
unsigned idx = 0;
unsigned pool_offset = atomic_add_return(1, &start_pool);
unsigned shrink_pages = sc->nr_to_scan;
struct device_pools *p;
if (list_empty(&_manager->pools))
return 0;
mutex_lock(&_manager->lock);
pool_offset = pool_offset % _manager->npools;
list_for_each_entry(p, &_manager->pools, pools) {
unsigned nr_free;
if (!p->dev)
continue;
if (shrink_pages == 0)
break;
/* Do it in round-robin fashion. */
if (++idx < pool_offset)
continue;
nr_free = shrink_pages;
shrink_pages = ttm_dma_page_pool_free(p->pool, nr_free);
pr_debug("%s: (%s:%d) Asked to shrink %d, have %d more to go\n",
p->pool->dev_name, p->pool->name, current->pid,
nr_free, shrink_pages);
}
mutex_unlock(&_manager->lock);
/* return estimated number of unused pages in pool */
return ttm_dma_pool_get_num_unused_pages();
}
static void ttm_dma_pool_mm_shrink_init(struct ttm_pool_manager *manager)
{
manager->mm_shrink.shrink = &ttm_dma_pool_mm_shrink;
manager->mm_shrink.seeks = 1;
register_shrinker(&manager->mm_shrink);
}
static void ttm_dma_pool_mm_shrink_fini(struct ttm_pool_manager *manager)
{
unregister_shrinker(&manager->mm_shrink);
}
int ttm_dma_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
{
int ret = -ENOMEM;
WARN_ON(_manager);
pr_info("Initializing DMA pool allocator\n");
_manager = kzalloc(sizeof(*_manager), GFP_KERNEL);
if (!_manager)
goto err;
mutex_init(&_manager->lock);
INIT_LIST_HEAD(&_manager->pools);
_manager->options.max_size = max_pages;
_manager->options.small = SMALL_ALLOCATION;
_manager->options.alloc_size = NUM_PAGES_TO_ALLOC;
/* This takes care of auto-freeing the _manager */
ret = kobject_init_and_add(&_manager->kobj, &ttm_pool_kobj_type,
&glob->kobj, "dma_pool");
if (unlikely(ret != 0)) {
kobject_put(&_manager->kobj);
goto err;
}
ttm_dma_pool_mm_shrink_init(_manager);
return 0;
err:
return ret;
}
void ttm_dma_page_alloc_fini(void)
{
struct device_pools *p, *t;
pr_info("Finalizing DMA pool allocator\n");
ttm_dma_pool_mm_shrink_fini(_manager);
list_for_each_entry_safe_reverse(p, t, &_manager->pools, pools) {
dev_dbg(p->dev, "(%s:%d) Freeing.\n", p->pool->name,
current->pid);
WARN_ON(devres_destroy(p->dev, ttm_dma_pool_release,
ttm_dma_pool_match, p->pool));
ttm_dma_free_pool(p->dev, p->pool->type);
}
kobject_put(&_manager->kobj);
_manager = NULL;
}
int ttm_dma_page_alloc_debugfs(struct seq_file *m, void *data)
{
struct device_pools *p;
struct dma_pool *pool = NULL;
char *h[] = {"pool", "refills", "pages freed", "inuse", "available",
"name", "virt", "busaddr"};
if (!_manager) {
seq_printf(m, "No pool allocator running.\n");
return 0;
}
seq_printf(m, "%13s %12s %13s %8s %8s %8s\n",
h[0], h[1], h[2], h[3], h[4], h[5]);
mutex_lock(&_manager->lock);
list_for_each_entry(p, &_manager->pools, pools) {
struct device *dev = p->dev;
if (!dev)
continue;
pool = p->pool;
seq_printf(m, "%13s %12ld %13ld %8d %8d %8s\n",
pool->name, pool->nrefills,
pool->nfrees, pool->npages_in_use,
pool->npages_free,
pool->dev_name);
}
mutex_unlock(&_manager->lock);
return 0;
}
EXPORT_SYMBOL_GPL(ttm_dma_page_alloc_debugfs);