blob: 1bba0a0ed3f996fbef159085dffd6b6c8f60355b [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0 OR MIT
/*
* Copyright 2020 Advanced Micro Devices, Inc.
*
* 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, sublicense,
* 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 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 NONINFRINGEMENT. IN NO EVENT SHALL
* THE COPYRIGHT HOLDER(S) OR AUTHOR(S) 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.
*
* Authors: Christian K├Ânig
*/
/* Pooling of allocated pages is necessary because changing the caching
* attributes on x86 of the linear mapping requires a costly cross CPU TLB
* invalidate for those addresses.
*
* Additional to that allocations from the DMA coherent API are pooled as well
* cause they are rather slow compared to alloc_pages+map.
*/
#include <linux/module.h>
#include <linux/dma-mapping.h>
#include <linux/highmem.h>
#include <linux/sched/mm.h>
#ifdef CONFIG_X86
#include <asm/set_memory.h>
#endif
#include <drm/ttm/ttm_pool.h>
#include <drm/ttm/ttm_bo_driver.h>
#include <drm/ttm/ttm_tt.h>
#include "ttm_module.h"
/**
* struct ttm_pool_dma - Helper object for coherent DMA mappings
*
* @addr: original DMA address returned for the mapping
* @vaddr: original vaddr return for the mapping and order in the lower bits
*/
struct ttm_pool_dma {
dma_addr_t addr;
unsigned long vaddr;
};
static unsigned long page_pool_size;
MODULE_PARM_DESC(page_pool_size, "Number of pages in the WC/UC/DMA pool");
module_param(page_pool_size, ulong, 0644);
static atomic_long_t allocated_pages;
static struct ttm_pool_type global_write_combined[MAX_ORDER];
static struct ttm_pool_type global_uncached[MAX_ORDER];
static struct ttm_pool_type global_dma32_write_combined[MAX_ORDER];
static struct ttm_pool_type global_dma32_uncached[MAX_ORDER];
static spinlock_t shrinker_lock;
static struct list_head shrinker_list;
static struct shrinker mm_shrinker;
/* Allocate pages of size 1 << order with the given gfp_flags */
static struct page *ttm_pool_alloc_page(struct ttm_pool *pool, gfp_t gfp_flags,
unsigned int order)
{
unsigned long attr = DMA_ATTR_FORCE_CONTIGUOUS;
struct ttm_pool_dma *dma;
struct page *p;
void *vaddr;
/* Don't set the __GFP_COMP flag for higher order allocations.
* Mapping pages directly into an userspace process and calling
* put_page() on a TTM allocated page is illegal.
*/
if (order)
gfp_flags |= __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN |
__GFP_KSWAPD_RECLAIM;
if (!pool->use_dma_alloc) {
p = alloc_pages(gfp_flags, order);
if (p)
p->private = order;
return p;
}
dma = kmalloc(sizeof(*dma), GFP_KERNEL);
if (!dma)
return NULL;
if (order)
attr |= DMA_ATTR_NO_WARN;
vaddr = dma_alloc_attrs(pool->dev, (1ULL << order) * PAGE_SIZE,
&dma->addr, gfp_flags, attr);
if (!vaddr)
goto error_free;
/* TODO: This is an illegal abuse of the DMA API, but we need to rework
* TTM page fault handling and extend the DMA API to clean this up.
*/
if (is_vmalloc_addr(vaddr))
p = vmalloc_to_page(vaddr);
else
p = virt_to_page(vaddr);
dma->vaddr = (unsigned long)vaddr | order;
p->private = (unsigned long)dma;
return p;
error_free:
kfree(dma);
return NULL;
}
/* Reset the caching and pages of size 1 << order */
static void ttm_pool_free_page(struct ttm_pool *pool, enum ttm_caching caching,
unsigned int order, struct page *p)
{
unsigned long attr = DMA_ATTR_FORCE_CONTIGUOUS;
struct ttm_pool_dma *dma;
void *vaddr;
#ifdef CONFIG_X86
/* We don't care that set_pages_wb is inefficient here. This is only
* used when we have to shrink and CPU overhead is irrelevant then.
*/
if (caching != ttm_cached && !PageHighMem(p))
set_pages_wb(p, 1 << order);
#endif
if (!pool || !pool->use_dma_alloc) {
__free_pages(p, order);
return;
}
if (order)
attr |= DMA_ATTR_NO_WARN;
dma = (void *)p->private;
vaddr = (void *)(dma->vaddr & PAGE_MASK);
dma_free_attrs(pool->dev, (1UL << order) * PAGE_SIZE, vaddr, dma->addr,
attr);
kfree(dma);
}
/* Apply a new caching to an array of pages */
static int ttm_pool_apply_caching(struct page **first, struct page **last,
enum ttm_caching caching)
{
#ifdef CONFIG_X86
unsigned int num_pages = last - first;
if (!num_pages)
return 0;
switch (caching) {
case ttm_cached:
break;
case ttm_write_combined:
return set_pages_array_wc(first, num_pages);
case ttm_uncached:
return set_pages_array_uc(first, num_pages);
}
#endif
return 0;
}
/* Map pages of 1 << order size and fill the DMA address array */
static int ttm_pool_map(struct ttm_pool *pool, unsigned int order,
struct page *p, dma_addr_t **dma_addr)
{
dma_addr_t addr;
unsigned int i;
if (pool->use_dma_alloc) {
struct ttm_pool_dma *dma = (void *)p->private;
addr = dma->addr;
} else {
size_t size = (1ULL << order) * PAGE_SIZE;
addr = dma_map_page(pool->dev, p, 0, size, DMA_BIDIRECTIONAL);
if (dma_mapping_error(pool->dev, addr))
return -EFAULT;
}
for (i = 1 << order; i ; --i) {
*(*dma_addr)++ = addr;
addr += PAGE_SIZE;
}
return 0;
}
/* Unmap pages of 1 << order size */
static void ttm_pool_unmap(struct ttm_pool *pool, dma_addr_t dma_addr,
unsigned int num_pages)
{
/* Unmapped while freeing the page */
if (pool->use_dma_alloc)
return;
dma_unmap_page(pool->dev, dma_addr, (long)num_pages << PAGE_SHIFT,
DMA_BIDIRECTIONAL);
}
/* Give pages into a specific pool_type */
static void ttm_pool_type_give(struct ttm_pool_type *pt, struct page *p)
{
unsigned int i, num_pages = 1 << pt->order;
for (i = 0; i < num_pages; ++i) {
if (PageHighMem(p))
clear_highpage(p + i);
else
clear_page(page_address(p + i));
}
spin_lock(&pt->lock);
list_add(&p->lru, &pt->pages);
spin_unlock(&pt->lock);
atomic_long_add(1 << pt->order, &allocated_pages);
}
/* Take pages from a specific pool_type, return NULL when nothing available */
static struct page *ttm_pool_type_take(struct ttm_pool_type *pt)
{
struct page *p;
spin_lock(&pt->lock);
p = list_first_entry_or_null(&pt->pages, typeof(*p), lru);
if (p) {
atomic_long_sub(1 << pt->order, &allocated_pages);
list_del(&p->lru);
}
spin_unlock(&pt->lock);
return p;
}
/* Initialize and add a pool type to the global shrinker list */
static void ttm_pool_type_init(struct ttm_pool_type *pt, struct ttm_pool *pool,
enum ttm_caching caching, unsigned int order)
{
pt->pool = pool;
pt->caching = caching;
pt->order = order;
spin_lock_init(&pt->lock);
INIT_LIST_HEAD(&pt->pages);
spin_lock(&shrinker_lock);
list_add_tail(&pt->shrinker_list, &shrinker_list);
spin_unlock(&shrinker_lock);
}
/* Remove a pool_type from the global shrinker list and free all pages */
static void ttm_pool_type_fini(struct ttm_pool_type *pt)
{
struct page *p;
spin_lock(&shrinker_lock);
list_del(&pt->shrinker_list);
spin_unlock(&shrinker_lock);
while ((p = ttm_pool_type_take(pt)))
ttm_pool_free_page(pt->pool, pt->caching, pt->order, p);
}
/* Return the pool_type to use for the given caching and order */
static struct ttm_pool_type *ttm_pool_select_type(struct ttm_pool *pool,
enum ttm_caching caching,
unsigned int order)
{
if (pool->use_dma_alloc)
return &pool->caching[caching].orders[order];
#ifdef CONFIG_X86
switch (caching) {
case ttm_write_combined:
if (pool->use_dma32)
return &global_dma32_write_combined[order];
return &global_write_combined[order];
case ttm_uncached:
if (pool->use_dma32)
return &global_dma32_uncached[order];
return &global_uncached[order];
default:
break;
}
#endif
return NULL;
}
/* Free pages using the global shrinker list */
static unsigned int ttm_pool_shrink(void)
{
struct ttm_pool_type *pt;
unsigned int num_pages;
struct page *p;
spin_lock(&shrinker_lock);
pt = list_first_entry(&shrinker_list, typeof(*pt), shrinker_list);
list_move_tail(&pt->shrinker_list, &shrinker_list);
spin_unlock(&shrinker_lock);
p = ttm_pool_type_take(pt);
if (p) {
ttm_pool_free_page(pt->pool, pt->caching, pt->order, p);
num_pages = 1 << pt->order;
} else {
num_pages = 0;
}
return num_pages;
}
/* Return the allocation order based for a page */
static unsigned int ttm_pool_page_order(struct ttm_pool *pool, struct page *p)
{
if (pool->use_dma_alloc) {
struct ttm_pool_dma *dma = (void *)p->private;
return dma->vaddr & ~PAGE_MASK;
}
return p->private;
}
/**
* ttm_pool_alloc - Fill a ttm_tt object
*
* @pool: ttm_pool to use
* @tt: ttm_tt object to fill
* @ctx: operation context
*
* Fill the ttm_tt object with pages and also make sure to DMA map them when
* necessary.
*
* Returns: 0 on successe, negative error code otherwise.
*/
int ttm_pool_alloc(struct ttm_pool *pool, struct ttm_tt *tt,
struct ttm_operation_ctx *ctx)
{
unsigned long num_pages = tt->num_pages;
dma_addr_t *dma_addr = tt->dma_address;
struct page **caching = tt->pages;
struct page **pages = tt->pages;
gfp_t gfp_flags = GFP_USER;
unsigned int i, order;
struct page *p;
int r;
WARN_ON(!num_pages || ttm_tt_is_populated(tt));
WARN_ON(dma_addr && !pool->dev);
if (tt->page_flags & TTM_TT_FLAG_ZERO_ALLOC)
gfp_flags |= __GFP_ZERO;
if (ctx->gfp_retry_mayfail)
gfp_flags |= __GFP_RETRY_MAYFAIL;
if (pool->use_dma32)
gfp_flags |= GFP_DMA32;
else
gfp_flags |= GFP_HIGHUSER;
for (order = min_t(unsigned int, MAX_ORDER - 1, __fls(num_pages));
num_pages;
order = min_t(unsigned int, order, __fls(num_pages))) {
bool apply_caching = false;
struct ttm_pool_type *pt;
pt = ttm_pool_select_type(pool, tt->caching, order);
p = pt ? ttm_pool_type_take(pt) : NULL;
if (p) {
apply_caching = true;
} else {
p = ttm_pool_alloc_page(pool, gfp_flags, order);
if (p && PageHighMem(p))
apply_caching = true;
}
if (!p) {
if (order) {
--order;
continue;
}
r = -ENOMEM;
goto error_free_all;
}
if (apply_caching) {
r = ttm_pool_apply_caching(caching, pages,
tt->caching);
if (r)
goto error_free_page;
caching = pages + (1 << order);
}
if (dma_addr) {
r = ttm_pool_map(pool, order, p, &dma_addr);
if (r)
goto error_free_page;
}
num_pages -= 1 << order;
for (i = 1 << order; i; --i)
*(pages++) = p++;
}
r = ttm_pool_apply_caching(caching, pages, tt->caching);
if (r)
goto error_free_all;
return 0;
error_free_page:
ttm_pool_free_page(pool, tt->caching, order, p);
error_free_all:
num_pages = tt->num_pages - num_pages;
for (i = 0; i < num_pages; ) {
order = ttm_pool_page_order(pool, tt->pages[i]);
ttm_pool_free_page(pool, tt->caching, order, tt->pages[i]);
i += 1 << order;
}
return r;
}
EXPORT_SYMBOL(ttm_pool_alloc);
/**
* ttm_pool_free - Free the backing pages from a ttm_tt object
*
* @pool: Pool to give pages back to.
* @tt: ttm_tt object to unpopulate
*
* Give the packing pages back to a pool or free them
*/
void ttm_pool_free(struct ttm_pool *pool, struct ttm_tt *tt)
{
unsigned int i;
for (i = 0; i < tt->num_pages; ) {
struct page *p = tt->pages[i];
unsigned int order, num_pages;
struct ttm_pool_type *pt;
order = ttm_pool_page_order(pool, p);
num_pages = 1ULL << order;
if (tt->dma_address)
ttm_pool_unmap(pool, tt->dma_address[i], num_pages);
pt = ttm_pool_select_type(pool, tt->caching, order);
if (pt)
ttm_pool_type_give(pt, tt->pages[i]);
else
ttm_pool_free_page(pool, tt->caching, order,
tt->pages[i]);
i += num_pages;
}
while (atomic_long_read(&allocated_pages) > page_pool_size)
ttm_pool_shrink();
}
EXPORT_SYMBOL(ttm_pool_free);
/**
* ttm_pool_init - Initialize a pool
*
* @pool: the pool to initialize
* @dev: device for DMA allocations and mappings
* @use_dma_alloc: true if coherent DMA alloc should be used
* @use_dma32: true if GFP_DMA32 should be used
*
* Initialize the pool and its pool types.
*/
void ttm_pool_init(struct ttm_pool *pool, struct device *dev,
bool use_dma_alloc, bool use_dma32)
{
unsigned int i, j;
WARN_ON(!dev && use_dma_alloc);
pool->dev = dev;
pool->use_dma_alloc = use_dma_alloc;
pool->use_dma32 = use_dma32;
if (use_dma_alloc) {
for (i = 0; i < TTM_NUM_CACHING_TYPES; ++i)
for (j = 0; j < MAX_ORDER; ++j)
ttm_pool_type_init(&pool->caching[i].orders[j],
pool, i, j);
}
}
/**
* ttm_pool_fini - Cleanup a pool
*
* @pool: the pool to clean up
*
* Free all pages in the pool and unregister the types from the global
* shrinker.
*/
void ttm_pool_fini(struct ttm_pool *pool)
{
unsigned int i, j;
if (pool->use_dma_alloc) {
for (i = 0; i < TTM_NUM_CACHING_TYPES; ++i)
for (j = 0; j < MAX_ORDER; ++j)
ttm_pool_type_fini(&pool->caching[i].orders[j]);
}
/* We removed the pool types from the LRU, but we need to also make sure
* that no shrinker is concurrently freeing pages from the pool.
*/
synchronize_shrinkers();
}
/* As long as pages are available make sure to release at least one */
static unsigned long ttm_pool_shrinker_scan(struct shrinker *shrink,
struct shrink_control *sc)
{
unsigned long num_freed = 0;
do
num_freed += ttm_pool_shrink();
while (!num_freed && atomic_long_read(&allocated_pages));
return num_freed;
}
/* Return the number of pages available or SHRINK_EMPTY if we have none */
static unsigned long ttm_pool_shrinker_count(struct shrinker *shrink,
struct shrink_control *sc)
{
unsigned long num_pages = atomic_long_read(&allocated_pages);
return num_pages ? num_pages : SHRINK_EMPTY;
}
#ifdef CONFIG_DEBUG_FS
/* Count the number of pages available in a pool_type */
static unsigned int ttm_pool_type_count(struct ttm_pool_type *pt)
{
unsigned int count = 0;
struct page *p;
spin_lock(&pt->lock);
/* Only used for debugfs, the overhead doesn't matter */
list_for_each_entry(p, &pt->pages, lru)
++count;
spin_unlock(&pt->lock);
return count;
}
/* Print a nice header for the order */
static void ttm_pool_debugfs_header(struct seq_file *m)
{
unsigned int i;
seq_puts(m, "\t ");
for (i = 0; i < MAX_ORDER; ++i)
seq_printf(m, " ---%2u---", i);
seq_puts(m, "\n");
}
/* Dump information about the different pool types */
static void ttm_pool_debugfs_orders(struct ttm_pool_type *pt,
struct seq_file *m)
{
unsigned int i;
for (i = 0; i < MAX_ORDER; ++i)
seq_printf(m, " %8u", ttm_pool_type_count(&pt[i]));
seq_puts(m, "\n");
}
/* Dump the total amount of allocated pages */
static void ttm_pool_debugfs_footer(struct seq_file *m)
{
seq_printf(m, "\ntotal\t: %8lu of %8lu\n",
atomic_long_read(&allocated_pages), page_pool_size);
}
/* Dump the information for the global pools */
static int ttm_pool_debugfs_globals_show(struct seq_file *m, void *data)
{
ttm_pool_debugfs_header(m);
spin_lock(&shrinker_lock);
seq_puts(m, "wc\t:");
ttm_pool_debugfs_orders(global_write_combined, m);
seq_puts(m, "uc\t:");
ttm_pool_debugfs_orders(global_uncached, m);
seq_puts(m, "wc 32\t:");
ttm_pool_debugfs_orders(global_dma32_write_combined, m);
seq_puts(m, "uc 32\t:");
ttm_pool_debugfs_orders(global_dma32_uncached, m);
spin_unlock(&shrinker_lock);
ttm_pool_debugfs_footer(m);
return 0;
}
DEFINE_SHOW_ATTRIBUTE(ttm_pool_debugfs_globals);
/**
* ttm_pool_debugfs - Debugfs dump function for a pool
*
* @pool: the pool to dump the information for
* @m: seq_file to dump to
*
* Make a debugfs dump with the per pool and global information.
*/
int ttm_pool_debugfs(struct ttm_pool *pool, struct seq_file *m)
{
unsigned int i;
if (!pool->use_dma_alloc) {
seq_puts(m, "unused\n");
return 0;
}
ttm_pool_debugfs_header(m);
spin_lock(&shrinker_lock);
for (i = 0; i < TTM_NUM_CACHING_TYPES; ++i) {
seq_puts(m, "DMA ");
switch (i) {
case ttm_cached:
seq_puts(m, "\t:");
break;
case ttm_write_combined:
seq_puts(m, "wc\t:");
break;
case ttm_uncached:
seq_puts(m, "uc\t:");
break;
}
ttm_pool_debugfs_orders(pool->caching[i].orders, m);
}
spin_unlock(&shrinker_lock);
ttm_pool_debugfs_footer(m);
return 0;
}
EXPORT_SYMBOL(ttm_pool_debugfs);
/* Test the shrinker functions and dump the result */
static int ttm_pool_debugfs_shrink_show(struct seq_file *m, void *data)
{
struct shrink_control sc = { .gfp_mask = GFP_NOFS };
fs_reclaim_acquire(GFP_KERNEL);
seq_printf(m, "%lu/%lu\n", ttm_pool_shrinker_count(&mm_shrinker, &sc),
ttm_pool_shrinker_scan(&mm_shrinker, &sc));
fs_reclaim_release(GFP_KERNEL);
return 0;
}
DEFINE_SHOW_ATTRIBUTE(ttm_pool_debugfs_shrink);
#endif
/**
* ttm_pool_mgr_init - Initialize globals
*
* @num_pages: default number of pages
*
* Initialize the global locks and lists for the MM shrinker.
*/
int ttm_pool_mgr_init(unsigned long num_pages)
{
unsigned int i;
if (!page_pool_size)
page_pool_size = num_pages;
spin_lock_init(&shrinker_lock);
INIT_LIST_HEAD(&shrinker_list);
for (i = 0; i < MAX_ORDER; ++i) {
ttm_pool_type_init(&global_write_combined[i], NULL,
ttm_write_combined, i);
ttm_pool_type_init(&global_uncached[i], NULL, ttm_uncached, i);
ttm_pool_type_init(&global_dma32_write_combined[i], NULL,
ttm_write_combined, i);
ttm_pool_type_init(&global_dma32_uncached[i], NULL,
ttm_uncached, i);
}
#ifdef CONFIG_DEBUG_FS
debugfs_create_file("page_pool", 0444, ttm_debugfs_root, NULL,
&ttm_pool_debugfs_globals_fops);
debugfs_create_file("page_pool_shrink", 0400, ttm_debugfs_root, NULL,
&ttm_pool_debugfs_shrink_fops);
#endif
mm_shrinker.count_objects = ttm_pool_shrinker_count;
mm_shrinker.scan_objects = ttm_pool_shrinker_scan;
mm_shrinker.seeks = 1;
return register_shrinker(&mm_shrinker);
}
/**
* ttm_pool_mgr_fini - Finalize globals
*
* Cleanup the global pools and unregister the MM shrinker.
*/
void ttm_pool_mgr_fini(void)
{
unsigned int i;
for (i = 0; i < MAX_ORDER; ++i) {
ttm_pool_type_fini(&global_write_combined[i]);
ttm_pool_type_fini(&global_uncached[i]);
ttm_pool_type_fini(&global_dma32_write_combined[i]);
ttm_pool_type_fini(&global_dma32_uncached[i]);
}
unregister_shrinker(&mm_shrinker);
WARN_ON(!list_empty(&shrinker_list));
}