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/**************************************************************************
*
* Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
* All Rights Reserved.
*
* 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 COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS 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: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
*/
#include <linux/vmalloc.h>
#include <linux/sched.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <linux/file.h>
#include <linux/swap.h>
#include "drm_cache.h"
#include "ttm/ttm_module.h"
#include "ttm/ttm_bo_driver.h"
#include "ttm/ttm_placement.h"
static int ttm_tt_swapin(struct ttm_tt *ttm);
/**
* Allocates storage for pointers to the pages that back the ttm.
*
* Uses kmalloc if possible. Otherwise falls back to vmalloc.
*/
static void ttm_tt_alloc_page_directory(struct ttm_tt *ttm)
{
unsigned long size = ttm->num_pages * sizeof(*ttm->pages);
ttm->pages = NULL;
if (size <= PAGE_SIZE)
ttm->pages = kzalloc(size, GFP_KERNEL);
if (!ttm->pages) {
ttm->pages = vmalloc_user(size);
if (ttm->pages)
ttm->page_flags |= TTM_PAGE_FLAG_VMALLOC;
}
}
static void ttm_tt_free_page_directory(struct ttm_tt *ttm)
{
if (ttm->page_flags & TTM_PAGE_FLAG_VMALLOC) {
vfree(ttm->pages);
ttm->page_flags &= ~TTM_PAGE_FLAG_VMALLOC;
} else {
kfree(ttm->pages);
}
ttm->pages = NULL;
}
static struct page *ttm_tt_alloc_page(unsigned page_flags)
{
gfp_t gfp_flags = GFP_USER;
if (page_flags & TTM_PAGE_FLAG_ZERO_ALLOC)
gfp_flags |= __GFP_ZERO;
if (page_flags & TTM_PAGE_FLAG_DMA32)
gfp_flags |= __GFP_DMA32;
else
gfp_flags |= __GFP_HIGHMEM;
return alloc_page(gfp_flags);
}
static void ttm_tt_free_user_pages(struct ttm_tt *ttm)
{
int write;
int dirty;
struct page *page;
int i;
struct ttm_backend *be = ttm->be;
BUG_ON(!(ttm->page_flags & TTM_PAGE_FLAG_USER));
write = ((ttm->page_flags & TTM_PAGE_FLAG_WRITE) != 0);
dirty = ((ttm->page_flags & TTM_PAGE_FLAG_USER_DIRTY) != 0);
if (be)
be->func->clear(be);
for (i = 0; i < ttm->num_pages; ++i) {
page = ttm->pages[i];
if (page == NULL)
continue;
if (page == ttm->dummy_read_page) {
BUG_ON(write);
continue;
}
if (write && dirty && !PageReserved(page))
set_page_dirty_lock(page);
ttm->pages[i] = NULL;
ttm_mem_global_free(ttm->glob->mem_glob, PAGE_SIZE);
put_page(page);
}
ttm->state = tt_unpopulated;
ttm->first_himem_page = ttm->num_pages;
ttm->last_lomem_page = -1;
}
static struct page *__ttm_tt_get_page(struct ttm_tt *ttm, int index)
{
struct page *p;
struct ttm_mem_global *mem_glob = ttm->glob->mem_glob;
int ret;
while (NULL == (p = ttm->pages[index])) {
p = ttm_tt_alloc_page(ttm->page_flags);
if (!p)
return NULL;
ret = ttm_mem_global_alloc_page(mem_glob, p, false, false);
if (unlikely(ret != 0))
goto out_err;
if (PageHighMem(p))
ttm->pages[--ttm->first_himem_page] = p;
else
ttm->pages[++ttm->last_lomem_page] = p;
}
return p;
out_err:
put_page(p);
return NULL;
}
struct page *ttm_tt_get_page(struct ttm_tt *ttm, int index)
{
int ret;
if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
ret = ttm_tt_swapin(ttm);
if (unlikely(ret != 0))
return NULL;
}
return __ttm_tt_get_page(ttm, index);
}
int ttm_tt_populate(struct ttm_tt *ttm)
{
struct page *page;
unsigned long i;
struct ttm_backend *be;
int ret;
if (ttm->state != tt_unpopulated)
return 0;
if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
ret = ttm_tt_swapin(ttm);
if (unlikely(ret != 0))
return ret;
}
be = ttm->be;
for (i = 0; i < ttm->num_pages; ++i) {
page = __ttm_tt_get_page(ttm, i);
if (!page)
return -ENOMEM;
}
be->func->populate(be, ttm->num_pages, ttm->pages,
ttm->dummy_read_page);
ttm->state = tt_unbound;
return 0;
}
#ifdef CONFIG_X86
static inline int ttm_tt_set_page_caching(struct page *p,
enum ttm_caching_state c_state)
{
if (PageHighMem(p))
return 0;
switch (c_state) {
case tt_cached:
return set_pages_wb(p, 1);
case tt_wc:
return set_memory_wc((unsigned long) page_address(p), 1);
default:
return set_pages_uc(p, 1);
}
}
#else /* CONFIG_X86 */
static inline int ttm_tt_set_page_caching(struct page *p,
enum ttm_caching_state c_state)
{
return 0;
}
#endif /* CONFIG_X86 */
/*
* Change caching policy for the linear kernel map
* for range of pages in a ttm.
*/
static int ttm_tt_set_caching(struct ttm_tt *ttm,
enum ttm_caching_state c_state)
{
int i, j;
struct page *cur_page;
int ret;
if (ttm->caching_state == c_state)
return 0;
if (c_state != tt_cached) {
ret = ttm_tt_populate(ttm);
if (unlikely(ret != 0))
return ret;
}
if (ttm->caching_state == tt_cached)
drm_clflush_pages(ttm->pages, ttm->num_pages);
for (i = 0; i < ttm->num_pages; ++i) {
cur_page = ttm->pages[i];
if (likely(cur_page != NULL)) {
ret = ttm_tt_set_page_caching(cur_page, c_state);
if (unlikely(ret != 0))
goto out_err;
}
}
ttm->caching_state = c_state;
return 0;
out_err:
for (j = 0; j < i; ++j) {
cur_page = ttm->pages[j];
if (likely(cur_page != NULL)) {
(void)ttm_tt_set_page_caching(cur_page,
ttm->caching_state);
}
}
return ret;
}
int ttm_tt_set_placement_caching(struct ttm_tt *ttm, uint32_t placement)
{
enum ttm_caching_state state;
if (placement & TTM_PL_FLAG_WC)
state = tt_wc;
else if (placement & TTM_PL_FLAG_UNCACHED)
state = tt_uncached;
else
state = tt_cached;
return ttm_tt_set_caching(ttm, state);
}
EXPORT_SYMBOL(ttm_tt_set_placement_caching);
static void ttm_tt_free_alloced_pages(struct ttm_tt *ttm)
{
int i;
struct page *cur_page;
struct ttm_backend *be = ttm->be;
if (be)
be->func->clear(be);
(void)ttm_tt_set_caching(ttm, tt_cached);
for (i = 0; i < ttm->num_pages; ++i) {
cur_page = ttm->pages[i];
ttm->pages[i] = NULL;
if (cur_page) {
if (page_count(cur_page) != 1)
printk(KERN_ERR TTM_PFX
"Erroneous page count. "
"Leaking pages.\n");
ttm_mem_global_free_page(ttm->glob->mem_glob,
cur_page);
__free_page(cur_page);
}
}
ttm->state = tt_unpopulated;
ttm->first_himem_page = ttm->num_pages;
ttm->last_lomem_page = -1;
}
void ttm_tt_destroy(struct ttm_tt *ttm)
{
struct ttm_backend *be;
if (unlikely(ttm == NULL))
return;
be = ttm->be;
if (likely(be != NULL)) {
be->func->destroy(be);
ttm->be = NULL;
}
if (likely(ttm->pages != NULL)) {
if (ttm->page_flags & TTM_PAGE_FLAG_USER)
ttm_tt_free_user_pages(ttm);
else
ttm_tt_free_alloced_pages(ttm);
ttm_tt_free_page_directory(ttm);
}
if (!(ttm->page_flags & TTM_PAGE_FLAG_PERSISTANT_SWAP) &&
ttm->swap_storage)
fput(ttm->swap_storage);
kfree(ttm);
}
int ttm_tt_set_user(struct ttm_tt *ttm,
struct task_struct *tsk,
unsigned long start, unsigned long num_pages)
{
struct mm_struct *mm = tsk->mm;
int ret;
int write = (ttm->page_flags & TTM_PAGE_FLAG_WRITE) != 0;
struct ttm_mem_global *mem_glob = ttm->glob->mem_glob;
BUG_ON(num_pages != ttm->num_pages);
BUG_ON((ttm->page_flags & TTM_PAGE_FLAG_USER) == 0);
/**
* Account user pages as lowmem pages for now.
*/
ret = ttm_mem_global_alloc(mem_glob, num_pages * PAGE_SIZE,
false, false);
if (unlikely(ret != 0))
return ret;
down_read(&mm->mmap_sem);
ret = get_user_pages(tsk, mm, start, num_pages,
write, 0, ttm->pages, NULL);
up_read(&mm->mmap_sem);
if (ret != num_pages && write) {
ttm_tt_free_user_pages(ttm);
ttm_mem_global_free(mem_glob, num_pages * PAGE_SIZE);
return -ENOMEM;
}
ttm->tsk = tsk;
ttm->start = start;
ttm->state = tt_unbound;
return 0;
}
struct ttm_tt *ttm_tt_create(struct ttm_bo_device *bdev, unsigned long size,
uint32_t page_flags, struct page *dummy_read_page)
{
struct ttm_bo_driver *bo_driver = bdev->driver;
struct ttm_tt *ttm;
if (!bo_driver)
return NULL;
ttm = kzalloc(sizeof(*ttm), GFP_KERNEL);
if (!ttm)
return NULL;
ttm->glob = bdev->glob;
ttm->num_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
ttm->first_himem_page = ttm->num_pages;
ttm->last_lomem_page = -1;
ttm->caching_state = tt_cached;
ttm->page_flags = page_flags;
ttm->dummy_read_page = dummy_read_page;
ttm_tt_alloc_page_directory(ttm);
if (!ttm->pages) {
ttm_tt_destroy(ttm);
printk(KERN_ERR TTM_PFX "Failed allocating page table\n");
return NULL;
}
ttm->be = bo_driver->create_ttm_backend_entry(bdev);
if (!ttm->be) {
ttm_tt_destroy(ttm);
printk(KERN_ERR TTM_PFX "Failed creating ttm backend entry\n");
return NULL;
}
ttm->state = tt_unpopulated;
return ttm;
}
void ttm_tt_unbind(struct ttm_tt *ttm)
{
int ret;
struct ttm_backend *be = ttm->be;
if (ttm->state == tt_bound) {
ret = be->func->unbind(be);
BUG_ON(ret);
ttm->state = tt_unbound;
}
}
int ttm_tt_bind(struct ttm_tt *ttm, struct ttm_mem_reg *bo_mem)
{
int ret = 0;
struct ttm_backend *be;
if (!ttm)
return -EINVAL;
if (ttm->state == tt_bound)
return 0;
be = ttm->be;
ret = ttm_tt_populate(ttm);
if (ret)
return ret;
ret = be->func->bind(be, bo_mem);
if (ret) {
printk(KERN_ERR TTM_PFX "Couldn't bind backend.\n");
return ret;
}
ttm->state = tt_bound;
if (ttm->page_flags & TTM_PAGE_FLAG_USER)
ttm->page_flags |= TTM_PAGE_FLAG_USER_DIRTY;
return 0;
}
EXPORT_SYMBOL(ttm_tt_bind);
static int ttm_tt_swapin(struct ttm_tt *ttm)
{
struct address_space *swap_space;
struct file *swap_storage;
struct page *from_page;
struct page *to_page;
void *from_virtual;
void *to_virtual;
int i;
int ret;
if (ttm->page_flags & TTM_PAGE_FLAG_USER) {
ret = ttm_tt_set_user(ttm, ttm->tsk, ttm->start,
ttm->num_pages);
if (unlikely(ret != 0))
return ret;
ttm->page_flags &= ~TTM_PAGE_FLAG_SWAPPED;
return 0;
}
swap_storage = ttm->swap_storage;
BUG_ON(swap_storage == NULL);
swap_space = swap_storage->f_path.dentry->d_inode->i_mapping;
for (i = 0; i < ttm->num_pages; ++i) {
from_page = read_mapping_page(swap_space, i, NULL);
if (IS_ERR(from_page))
goto out_err;
to_page = __ttm_tt_get_page(ttm, i);
if (unlikely(to_page == NULL))
goto out_err;
preempt_disable();
from_virtual = kmap_atomic(from_page, KM_USER0);
to_virtual = kmap_atomic(to_page, KM_USER1);
memcpy(to_virtual, from_virtual, PAGE_SIZE);
kunmap_atomic(to_virtual, KM_USER1);
kunmap_atomic(from_virtual, KM_USER0);
preempt_enable();
page_cache_release(from_page);
}
if (!(ttm->page_flags & TTM_PAGE_FLAG_PERSISTANT_SWAP))
fput(swap_storage);
ttm->swap_storage = NULL;
ttm->page_flags &= ~TTM_PAGE_FLAG_SWAPPED;
return 0;
out_err:
ttm_tt_free_alloced_pages(ttm);
return -ENOMEM;
}
int ttm_tt_swapout(struct ttm_tt *ttm, struct file *persistant_swap_storage)
{
struct address_space *swap_space;
struct file *swap_storage;
struct page *from_page;
struct page *to_page;
void *from_virtual;
void *to_virtual;
int i;
BUG_ON(ttm->state != tt_unbound && ttm->state != tt_unpopulated);
BUG_ON(ttm->caching_state != tt_cached);
/*
* For user buffers, just unpin the pages, as there should be
* vma references.
*/
if (ttm->page_flags & TTM_PAGE_FLAG_USER) {
ttm_tt_free_user_pages(ttm);
ttm->page_flags |= TTM_PAGE_FLAG_SWAPPED;
ttm->swap_storage = NULL;
return 0;
}
if (!persistant_swap_storage) {
swap_storage = shmem_file_setup("ttm swap",
ttm->num_pages << PAGE_SHIFT,
0);
if (unlikely(IS_ERR(swap_storage))) {
printk(KERN_ERR "Failed allocating swap storage.\n");
return -ENOMEM;
}
} else
swap_storage = persistant_swap_storage;
swap_space = swap_storage->f_path.dentry->d_inode->i_mapping;
for (i = 0; i < ttm->num_pages; ++i) {
from_page = ttm->pages[i];
if (unlikely(from_page == NULL))
continue;
to_page = read_mapping_page(swap_space, i, NULL);
if (unlikely(to_page == NULL))
goto out_err;
preempt_disable();
from_virtual = kmap_atomic(from_page, KM_USER0);
to_virtual = kmap_atomic(to_page, KM_USER1);
memcpy(to_virtual, from_virtual, PAGE_SIZE);
kunmap_atomic(to_virtual, KM_USER1);
kunmap_atomic(from_virtual, KM_USER0);
preempt_enable();
set_page_dirty(to_page);
mark_page_accessed(to_page);
page_cache_release(to_page);
}
ttm_tt_free_alloced_pages(ttm);
ttm->swap_storage = swap_storage;
ttm->page_flags |= TTM_PAGE_FLAG_SWAPPED;
if (persistant_swap_storage)
ttm->page_flags |= TTM_PAGE_FLAG_PERSISTANT_SWAP;
return 0;
out_err:
if (!persistant_swap_storage)
fput(swap_storage);
return -ENOMEM;
}