diff options
Diffstat (limited to 'drivers/gpu/drm/ttm/ttm_pool.c')
| -rw-r--r-- | drivers/gpu/drm/ttm/ttm_pool.c | 1377 |
1 files changed, 1377 insertions, 0 deletions
diff --git a/drivers/gpu/drm/ttm/ttm_pool.c b/drivers/gpu/drm/ttm/ttm_pool.c new file mode 100644 index 000000000000..18b6db015619 --- /dev/null +++ b/drivers/gpu/drm/ttm/ttm_pool.c @@ -0,0 +1,1377 @@ +// 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 König + */ + +/* 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/export.h> +#include <linux/module.h> +#include <linux/dma-mapping.h> +#include <linux/debugfs.h> +#include <linux/highmem.h> +#include <linux/sched/mm.h> + +#ifdef CONFIG_X86 +#include <asm/set_memory.h> +#endif + +#include <drm/ttm/ttm_backup.h> +#include <drm/ttm/ttm_pool.h> +#include <drm/ttm/ttm_tt.h> +#include <drm/ttm/ttm_bo.h> + +#include "ttm_module.h" +#include "ttm_pool_internal.h" + +#ifdef CONFIG_FAULT_INJECTION +#include <linux/fault-inject.h> +static DECLARE_FAULT_ATTR(backup_fault_inject); +#else +#define should_fail(...) false +#endif + +/** + * 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; +}; + +/** + * struct ttm_pool_alloc_state - Current state of the tt page allocation process + * @pages: Pointer to the next tt page pointer to populate. + * @caching_divide: Pointer to the first page pointer whose page has a staged but + * not committed caching transition from write-back to @tt_caching. + * @dma_addr: Pointer to the next tt dma_address entry to populate if any. + * @remaining_pages: Remaining pages to populate. + * @tt_caching: The requested cpu-caching for the pages allocated. + */ +struct ttm_pool_alloc_state { + struct page **pages; + struct page **caching_divide; + dma_addr_t *dma_addr; + pgoff_t remaining_pages; + enum ttm_caching tt_caching; +}; + +/** + * struct ttm_pool_tt_restore - State representing restore from backup + * @pool: The pool used for page allocation while restoring. + * @snapshot_alloc: A snapshot of the most recent struct ttm_pool_alloc_state. + * @alloced_page: Pointer to the page most recently allocated from a pool or system. + * @first_dma: The dma address corresponding to @alloced_page if dma_mapping + * is requested. + * @alloced_pages: The number of allocated pages present in the struct ttm_tt + * page vector from this restore session. + * @restored_pages: The number of 4K pages restored for @alloced_page (which + * is typically a multi-order page). + * @page_caching: The struct ttm_tt requested caching + * @order: The order of @alloced_page. + * + * Recovery from backup might fail when we've recovered less than the + * full ttm_tt. In order not to loose any data (yet), keep information + * around that allows us to restart a failed ttm backup recovery. + */ +struct ttm_pool_tt_restore { + struct ttm_pool *pool; + struct ttm_pool_alloc_state snapshot_alloc; + struct page *alloced_page; + dma_addr_t first_dma; + pgoff_t alloced_pages; + pgoff_t restored_pages; + enum ttm_caching page_caching; + unsigned int order; +}; + +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[NR_PAGE_ORDERS]; +static struct ttm_pool_type global_uncached[NR_PAGE_ORDERS]; + +static struct ttm_pool_type global_dma32_write_combined[NR_PAGE_ORDERS]; +static struct ttm_pool_type global_dma32_uncached[NR_PAGE_ORDERS]; + +static spinlock_t shrinker_lock; +static struct list_head shrinker_list; +static struct shrinker *mm_shrinker; +static DECLARE_RWSEM(pool_shrink_rwsem); + +/* 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) +{ + const unsigned int beneficial_order = ttm_pool_beneficial_order(pool); + 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_THISNODE; + + /* + * Do not add latency to the allocation path for allocations orders + * device tolds us do not bring them additional performance gains. + */ + if (beneficial_order && order > beneficial_order) + gfp_flags &= ~__GFP_DIRECT_RECLAIM; + + if (!ttm_pool_uses_dma_alloc(pool)) { + p = alloc_pages_node(pool->nid, 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 || !ttm_pool_uses_dma_alloc(pool)) { + __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 any cpu-caching deferred during page allocation */ +static int ttm_pool_apply_caching(struct ttm_pool_alloc_state *alloc) +{ +#ifdef CONFIG_X86 + unsigned int num_pages = alloc->pages - alloc->caching_divide; + + if (!num_pages) + return 0; + + switch (alloc->tt_caching) { + case ttm_cached: + break; + case ttm_write_combined: + return set_pages_array_wc(alloc->caching_divide, num_pages); + case ttm_uncached: + return set_pages_array_uc(alloc->caching_divide, num_pages); + } +#endif + alloc->caching_divide = alloc->pages; + return 0; +} + +/* DMA Map pages of 1 << order size and return the resulting dma_address. */ +static int ttm_pool_map(struct ttm_pool *pool, unsigned int order, + struct page *p, dma_addr_t *dma_addr) +{ + dma_addr_t addr; + + if (ttm_pool_uses_dma_alloc(pool)) { + 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; + } + + *dma_addr = addr; + + 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 (ttm_pool_uses_dma_alloc(pool)) + 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 (ttm_pool_uses_dma_alloc(pool)) + return &pool->caching[caching].orders[order]; + +#ifdef CONFIG_X86 + switch (caching) { + case ttm_write_combined: + if (pool->nid != NUMA_NO_NODE) + return &pool->caching[caching].orders[order]; + + if (ttm_pool_uses_dma32(pool)) + return &global_dma32_write_combined[order]; + + return &global_write_combined[order]; + case ttm_uncached: + if (pool->nid != NUMA_NO_NODE) + return &pool->caching[caching].orders[order]; + + if (ttm_pool_uses_dma32(pool)) + 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; + + down_read(&pool_shrink_rwsem); + 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; + } + up_read(&pool_shrink_rwsem); + + 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 (ttm_pool_uses_dma_alloc(pool)) { + struct ttm_pool_dma *dma = (void *)p->private; + + return dma->vaddr & ~PAGE_MASK; + } + + return p->private; +} + +/* + * Split larger pages so that we can free each PAGE_SIZE page as soon + * as it has been backed up, in order to avoid memory pressure during + * reclaim. + */ +static void ttm_pool_split_for_swap(struct ttm_pool *pool, struct page *p) +{ + unsigned int order = ttm_pool_page_order(pool, p); + pgoff_t nr; + + if (!order) + return; + + split_page(p, order); + nr = 1UL << order; + while (nr--) + (p++)->private = 0; +} + +/** + * DOC: Partial backup and restoration of a struct ttm_tt. + * + * Swapout using ttm_backup_backup_page() and swapin using + * ttm_backup_copy_page() may fail. + * The former most likely due to lack of swap-space or memory, the latter due + * to lack of memory or because of signal interruption during waits. + * + * Backup failure is easily handled by using a ttm_tt pages vector that holds + * both backup handles and page pointers. This has to be taken into account when + * restoring such a ttm_tt from backup, and when freeing it while backed up. + * When restoring, for simplicity, new pages are actually allocated from the + * pool and the contents of any old pages are copied in and then the old pages + * are released. + * + * For restoration failures, the struct ttm_pool_tt_restore holds sufficient state + * to be able to resume an interrupted restore, and that structure is freed once + * the restoration is complete. If the struct ttm_tt is destroyed while there + * is a valid struct ttm_pool_tt_restore attached, that is also properly taken + * care of. + */ + +/* Is restore ongoing for the currently allocated page? */ +static bool ttm_pool_restore_valid(const struct ttm_pool_tt_restore *restore) +{ + return restore && restore->restored_pages < (1 << restore->order); +} + +/* DMA unmap and free a multi-order page, either to the relevant pool or to system. */ +static pgoff_t ttm_pool_unmap_and_free(struct ttm_pool *pool, struct page *page, + const dma_addr_t *dma_addr, enum ttm_caching caching) +{ + struct ttm_pool_type *pt = NULL; + unsigned int order; + pgoff_t nr; + + if (pool) { + order = ttm_pool_page_order(pool, page); + nr = (1UL << order); + if (dma_addr) + ttm_pool_unmap(pool, *dma_addr, nr); + + pt = ttm_pool_select_type(pool, caching, order); + } else { + order = page->private; + nr = (1UL << order); + } + + if (pt) + ttm_pool_type_give(pt, page); + else + ttm_pool_free_page(pool, caching, order, page); + + return nr; +} + +/* Populate the page-array using the most recent allocated multi-order page. */ +static void ttm_pool_allocated_page_commit(struct page *allocated, + dma_addr_t first_dma, + struct ttm_pool_alloc_state *alloc, + pgoff_t nr) +{ + pgoff_t i; + + for (i = 0; i < nr; ++i) + *alloc->pages++ = allocated++; + + alloc->remaining_pages -= nr; + + if (!alloc->dma_addr) + return; + + for (i = 0; i < nr; ++i) { + *alloc->dma_addr++ = first_dma; + first_dma += PAGE_SIZE; + } +} + +/* + * When restoring, restore backed-up content to the newly allocated page and + * if successful, populate the page-table and dma-address arrays. + */ +static int ttm_pool_restore_commit(struct ttm_pool_tt_restore *restore, + struct file *backup, + const struct ttm_operation_ctx *ctx, + struct ttm_pool_alloc_state *alloc) + +{ + pgoff_t i, nr = 1UL << restore->order; + struct page **first_page = alloc->pages; + struct page *p; + int ret = 0; + + for (i = restore->restored_pages; i < nr; ++i) { + p = first_page[i]; + if (ttm_backup_page_ptr_is_handle(p)) { + unsigned long handle = ttm_backup_page_ptr_to_handle(p); + + if (IS_ENABLED(CONFIG_FAULT_INJECTION) && ctx->interruptible && + should_fail(&backup_fault_inject, 1)) { + ret = -EINTR; + break; + } + + if (handle == 0) { + restore->restored_pages++; + continue; + } + + ret = ttm_backup_copy_page(backup, restore->alloced_page + i, + handle, ctx->interruptible); + if (ret) + break; + + ttm_backup_drop(backup, handle); + } else if (p) { + /* + * We could probably avoid splitting the old page + * using clever logic, but ATM we don't care, as + * we prioritize releasing memory ASAP. Note that + * here, the old retained page is always write-back + * cached. + */ + ttm_pool_split_for_swap(restore->pool, p); + copy_highpage(restore->alloced_page + i, p); + __free_pages(p, 0); + } + + restore->restored_pages++; + first_page[i] = ttm_backup_handle_to_page_ptr(0); + } + + if (ret) { + if (!restore->restored_pages) { + dma_addr_t *dma_addr = alloc->dma_addr ? &restore->first_dma : NULL; + + ttm_pool_unmap_and_free(restore->pool, restore->alloced_page, + dma_addr, restore->page_caching); + restore->restored_pages = nr; + } + return ret; + } + + ttm_pool_allocated_page_commit(restore->alloced_page, restore->first_dma, + alloc, nr); + if (restore->page_caching == alloc->tt_caching || PageHighMem(restore->alloced_page)) + alloc->caching_divide = alloc->pages; + restore->snapshot_alloc = *alloc; + restore->alloced_pages += nr; + + return 0; +} + +/* If restoring, save information needed for ttm_pool_restore_commit(). */ +static void +ttm_pool_page_allocated_restore(struct ttm_pool *pool, unsigned int order, + struct page *p, + enum ttm_caching page_caching, + dma_addr_t first_dma, + struct ttm_pool_tt_restore *restore, + const struct ttm_pool_alloc_state *alloc) +{ + restore->pool = pool; + restore->order = order; + restore->restored_pages = 0; + restore->page_caching = page_caching; + restore->first_dma = first_dma; + restore->alloced_page = p; + restore->snapshot_alloc = *alloc; +} + +/* + * Called when we got a page, either from a pool or newly allocated. + * if needed, dma map the page and populate the dma address array. + * Populate the page address array. + * If the caching is consistent, update any deferred caching. Otherwise + * stage this page for an upcoming deferred caching update. + */ +static int ttm_pool_page_allocated(struct ttm_pool *pool, unsigned int order, + struct page *p, enum ttm_caching page_caching, + struct ttm_pool_alloc_state *alloc, + struct ttm_pool_tt_restore *restore) +{ + bool caching_consistent; + dma_addr_t first_dma; + int r = 0; + + caching_consistent = (page_caching == alloc->tt_caching) || PageHighMem(p); + + if (caching_consistent) { + r = ttm_pool_apply_caching(alloc); + if (r) + return r; + } + + if (alloc->dma_addr) { + r = ttm_pool_map(pool, order, p, &first_dma); + if (r) + return r; + } + + if (restore) { + ttm_pool_page_allocated_restore(pool, order, p, page_caching, + first_dma, restore, alloc); + } else { + ttm_pool_allocated_page_commit(p, first_dma, alloc, 1UL << order); + + if (caching_consistent) + alloc->caching_divide = alloc->pages; + } + + return 0; +} + +/** + * ttm_pool_free_range() - Free a range of TTM pages + * @pool: The pool used for allocating. + * @tt: The struct ttm_tt holding the page pointers. + * @caching: The page caching mode used by the range. + * @start_page: index for first page to free. + * @end_page: index for last page to free + 1. + * + * During allocation the ttm_tt page-vector may be populated with ranges of + * pages with different attributes if allocation hit an error without being + * able to completely fulfill the allocation. This function can be used + * to free these individual ranges. + */ +static void ttm_pool_free_range(struct ttm_pool *pool, struct ttm_tt *tt, + enum ttm_caching caching, + pgoff_t start_page, pgoff_t end_page) +{ + struct page **pages = &tt->pages[start_page]; + struct file *backup = tt->backup; + pgoff_t i, nr; + + for (i = start_page; i < end_page; i += nr, pages += nr) { + struct page *p = *pages; + + nr = 1; + if (ttm_backup_page_ptr_is_handle(p)) { + unsigned long handle = ttm_backup_page_ptr_to_handle(p); + + if (handle != 0) + ttm_backup_drop(backup, handle); + } else if (p) { + dma_addr_t *dma_addr = tt->dma_address ? + tt->dma_address + i : NULL; + + nr = ttm_pool_unmap_and_free(pool, p, dma_addr, caching); + } + } +} + +static void ttm_pool_alloc_state_init(const struct ttm_tt *tt, + struct ttm_pool_alloc_state *alloc) +{ + alloc->pages = tt->pages; + alloc->caching_divide = tt->pages; + alloc->dma_addr = tt->dma_address; + alloc->remaining_pages = tt->num_pages; + alloc->tt_caching = tt->caching; +} + +/* + * Find a suitable allocation order based on highest desired order + * and number of remaining pages + */ +static unsigned int ttm_pool_alloc_find_order(unsigned int highest, + const struct ttm_pool_alloc_state *alloc) +{ + return min_t(unsigned int, highest, __fls(alloc->remaining_pages)); +} + +static int __ttm_pool_alloc(struct ttm_pool *pool, struct ttm_tt *tt, + const struct ttm_operation_ctx *ctx, + struct ttm_pool_alloc_state *alloc, + struct ttm_pool_tt_restore *restore) +{ + enum ttm_caching page_caching; + gfp_t gfp_flags = GFP_USER; + pgoff_t caching_divide; + unsigned int order; + bool allow_pools; + struct page *p; + int r; + + WARN_ON(!alloc->remaining_pages || ttm_tt_is_populated(tt)); + WARN_ON(alloc->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 (ttm_pool_uses_dma32(pool)) + gfp_flags |= GFP_DMA32; + else + gfp_flags |= GFP_HIGHUSER; + + page_caching = tt->caching; + allow_pools = true; + for (order = ttm_pool_alloc_find_order(MAX_PAGE_ORDER, alloc); + alloc->remaining_pages; + order = ttm_pool_alloc_find_order(order, alloc)) { + struct ttm_pool_type *pt; + + /* First, try to allocate a page from a pool if one exists. */ + p = NULL; + pt = ttm_pool_select_type(pool, page_caching, order); + if (pt && allow_pools) + p = ttm_pool_type_take(pt); + /* + * If that fails or previously failed, allocate from system. + * Note that this also disallows additional pool allocations using + * write-back cached pools of the same order. Consider removing + * that behaviour. + */ + if (!p) { + page_caching = ttm_cached; + allow_pools = false; + p = ttm_pool_alloc_page(pool, gfp_flags, order); + } + /* If that fails, lower the order if possible and retry. */ + if (!p) { + if (order) { + --order; + page_caching = tt->caching; + allow_pools = true; + continue; + } + r = -ENOMEM; + goto error_free_all; + } + r = ttm_pool_page_allocated(pool, order, p, page_caching, alloc, + restore); + if (r) + goto error_free_page; + + if (ttm_pool_restore_valid(restore)) { + r = ttm_pool_restore_commit(restore, tt->backup, ctx, alloc); + if (r) + goto error_free_all; + } + } + + r = ttm_pool_apply_caching(alloc); + if (r) + goto error_free_all; + + kfree(tt->restore); + tt->restore = NULL; + + return 0; + +error_free_page: + ttm_pool_free_page(pool, page_caching, order, p); + +error_free_all: + if (tt->restore) + return r; + + caching_divide = alloc->caching_divide - tt->pages; + ttm_pool_free_range(pool, tt, tt->caching, 0, caching_divide); + ttm_pool_free_range(pool, tt, ttm_cached, caching_divide, + tt->num_pages - alloc->remaining_pages); + + return r; +} + +/** + * 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) +{ + struct ttm_pool_alloc_state alloc; + + if (WARN_ON(ttm_tt_is_backed_up(tt))) + return -EINVAL; + + ttm_pool_alloc_state_init(tt, &alloc); + + return __ttm_pool_alloc(pool, tt, ctx, &alloc, NULL); +} +EXPORT_SYMBOL(ttm_pool_alloc); + +/** + * ttm_pool_restore_and_alloc - Fill a ttm_tt, restoring previously backed-up + * content. + * + * @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. Read in backed-up content. + * + * Returns: 0 on successe, negative error code otherwise. + */ +int ttm_pool_restore_and_alloc(struct ttm_pool *pool, struct ttm_tt *tt, + const struct ttm_operation_ctx *ctx) +{ + struct ttm_pool_alloc_state alloc; + + if (WARN_ON(!ttm_tt_is_backed_up(tt))) + return -EINVAL; + + if (!tt->restore) { + gfp_t gfp = GFP_KERNEL | __GFP_NOWARN; + + ttm_pool_alloc_state_init(tt, &alloc); + if (ctx->gfp_retry_mayfail) + gfp |= __GFP_RETRY_MAYFAIL; + + tt->restore = kzalloc(sizeof(*tt->restore), gfp); + if (!tt->restore) + return -ENOMEM; + + tt->restore->snapshot_alloc = alloc; + tt->restore->pool = pool; + tt->restore->restored_pages = 1; + } else { + struct ttm_pool_tt_restore *restore = tt->restore; + int ret; + + alloc = restore->snapshot_alloc; + if (ttm_pool_restore_valid(tt->restore)) { + ret = ttm_pool_restore_commit(restore, tt->backup, ctx, &alloc); + if (ret) + return ret; + } + if (!alloc.remaining_pages) + return 0; + } + + return __ttm_pool_alloc(pool, tt, ctx, &alloc, tt->restore); +} + +/** + * 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) +{ + ttm_pool_free_range(pool, tt, tt->caching, 0, tt->num_pages); + + while (atomic_long_read(&allocated_pages) > page_pool_size) + ttm_pool_shrink(); +} +EXPORT_SYMBOL(ttm_pool_free); + +/** + * ttm_pool_drop_backed_up() - Release content of a swapped-out struct ttm_tt + * @tt: The struct ttm_tt. + * + * Release handles with associated content or any remaining pages of + * a backed-up struct ttm_tt. + */ +void ttm_pool_drop_backed_up(struct ttm_tt *tt) +{ + struct ttm_pool_tt_restore *restore; + pgoff_t start_page = 0; + + WARN_ON(!ttm_tt_is_backed_up(tt)); + + restore = tt->restore; + + /* + * Unmap and free any uncommitted restore page. + * any tt page-array backup entries already read back has + * been cleared already + */ + if (ttm_pool_restore_valid(restore)) { + dma_addr_t *dma_addr = tt->dma_address ? &restore->first_dma : NULL; + + ttm_pool_unmap_and_free(restore->pool, restore->alloced_page, + dma_addr, restore->page_caching); + restore->restored_pages = 1UL << restore->order; + } + + /* + * If a restore is ongoing, part of the tt pages may have a + * caching different than writeback. + */ + if (restore) { + pgoff_t mid = restore->snapshot_alloc.caching_divide - tt->pages; + + start_page = restore->alloced_pages; + WARN_ON(mid > start_page); + /* Pages that might be dma-mapped and non-cached */ + ttm_pool_free_range(restore->pool, tt, tt->caching, + 0, mid); + /* Pages that might be dma-mapped but cached */ + ttm_pool_free_range(restore->pool, tt, ttm_cached, + mid, restore->alloced_pages); + kfree(restore); + tt->restore = NULL; + } + + ttm_pool_free_range(NULL, tt, ttm_cached, start_page, tt->num_pages); +} + +/** + * ttm_pool_backup() - Back up or purge a struct ttm_tt + * @pool: The pool used when allocating the struct ttm_tt. + * @tt: The struct ttm_tt. + * @flags: Flags to govern the backup behaviour. + * + * Back up or purge a struct ttm_tt. If @purge is true, then + * all pages will be freed directly to the system rather than to the pool + * they were allocated from, making the function behave similarly to + * ttm_pool_free(). If @purge is false the pages will be backed up instead, + * exchanged for handles. + * A subsequent call to ttm_pool_restore_and_alloc() will then read back the content and + * a subsequent call to ttm_pool_drop_backed_up() will drop it. + * If backup of a page fails for whatever reason, @ttm will still be + * partially backed up, retaining those pages for which backup fails. + * In that case, this function can be retried, possibly after freeing up + * memory resources. + * + * Return: Number of pages actually backed up or freed, or negative + * error code on error. + */ +long ttm_pool_backup(struct ttm_pool *pool, struct ttm_tt *tt, + const struct ttm_backup_flags *flags) +{ + struct file *backup = tt->backup; + struct page *page; + unsigned long handle; + gfp_t alloc_gfp; + gfp_t gfp; + int ret = 0; + pgoff_t shrunken = 0; + pgoff_t i, num_pages; + + if (WARN_ON(ttm_tt_is_backed_up(tt))) + return -EINVAL; + + if ((!ttm_backup_bytes_avail() && !flags->purge) || + ttm_pool_uses_dma_alloc(pool) || ttm_tt_is_backed_up(tt)) + return -EBUSY; + +#ifdef CONFIG_X86 + /* Anything returned to the system needs to be cached. */ + if (tt->caching != ttm_cached) + set_pages_array_wb(tt->pages, tt->num_pages); +#endif + + if (tt->dma_address || flags->purge) { + for (i = 0; i < tt->num_pages; i += num_pages) { + unsigned int order; + + page = tt->pages[i]; + if (unlikely(!page)) { + num_pages = 1; + continue; + } + + order = ttm_pool_page_order(pool, page); + num_pages = 1UL << order; + if (tt->dma_address) + ttm_pool_unmap(pool, tt->dma_address[i], + num_pages); + if (flags->purge) { + shrunken += num_pages; + page->private = 0; + __free_pages(page, order); + memset(tt->pages + i, 0, + num_pages * sizeof(*tt->pages)); + } + } + } + + if (flags->purge) + return shrunken; + + if (ttm_pool_uses_dma32(pool)) + gfp = GFP_DMA32; + else + gfp = GFP_HIGHUSER; + + alloc_gfp = GFP_KERNEL | __GFP_HIGH | __GFP_NOWARN | __GFP_RETRY_MAYFAIL; + + num_pages = tt->num_pages; + + /* Pretend doing fault injection by shrinking only half of the pages. */ + if (IS_ENABLED(CONFIG_FAULT_INJECTION) && should_fail(&backup_fault_inject, 1)) + num_pages = DIV_ROUND_UP(num_pages, 2); + + for (i = 0; i < num_pages; ++i) { + s64 shandle; + + page = tt->pages[i]; + if (unlikely(!page)) + continue; + + ttm_pool_split_for_swap(pool, page); + + shandle = ttm_backup_backup_page(backup, page, flags->writeback, i, + gfp, alloc_gfp); + if (shandle < 0) { + /* We allow partially shrunken tts */ + ret = shandle; + break; + } + handle = shandle; + tt->pages[i] = ttm_backup_handle_to_page_ptr(handle); + put_page(page); + shrunken++; + } + + return shrunken ? shrunken : ret; +} + +/** + * ttm_pool_init - Initialize a pool + * + * @pool: the pool to initialize + * @dev: device for DMA allocations and mappings + * @nid: NUMA node to use for allocations + * @alloc_flags: TTM_ALLOCATION_POOL_* flags + * + * Initialize the pool and its pool types. + */ +void ttm_pool_init(struct ttm_pool *pool, struct device *dev, + int nid, unsigned int alloc_flags) +{ + unsigned int i, j; + + WARN_ON(!dev && ttm_pool_uses_dma_alloc(pool)); + + pool->dev = dev; + pool->nid = nid; + pool->alloc_flags = alloc_flags; + + for (i = 0; i < TTM_NUM_CACHING_TYPES; ++i) { + for (j = 0; j < NR_PAGE_ORDERS; ++j) { + struct ttm_pool_type *pt; + + /* Initialize only pool types which are actually used */ + pt = ttm_pool_select_type(pool, i, j); + if (pt != &pool->caching[i].orders[j]) + continue; + + ttm_pool_type_init(pt, pool, i, j); + } + } +} +EXPORT_SYMBOL(ttm_pool_init); + +/** + * ttm_pool_synchronize_shrinkers - Wait for all running shrinkers to complete. + * + * This is useful to guarantee that all shrinker invocations have seen an + * update, before freeing memory, similar to rcu. + */ +static void ttm_pool_synchronize_shrinkers(void) +{ + down_write(&pool_shrink_rwsem); + up_write(&pool_shrink_rwsem); +} + +/** + * 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; + + for (i = 0; i < TTM_NUM_CACHING_TYPES; ++i) { + for (j = 0; j < NR_PAGE_ORDERS; ++j) { + struct ttm_pool_type *pt; + + pt = ttm_pool_select_type(pool, i, j); + if (pt != &pool->caching[i].orders[j]) + continue; + + ttm_pool_type_fini(pt); + } + } + + /* 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. + */ + ttm_pool_synchronize_shrinkers(); +} +EXPORT_SYMBOL(ttm_pool_fini); + +/* Free average pool number of pages. */ +#define TTM_SHRINKER_BATCH ((1 << (MAX_PAGE_ORDER / 2)) * NR_PAGE_ORDERS) + +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 < sc->nr_to_scan && + atomic_long_read(&allocated_pages)); + + sc->nr_scanned = num_freed; + + return num_freed ?: SHRINK_STOP; +} + +/* 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 < NR_PAGE_ORDERS; ++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 < NR_PAGE_ORDERS; ++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 (!ttm_pool_uses_dma_alloc(pool) && pool->nid == NUMA_NO_NODE) { + 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) { + if (!ttm_pool_select_type(pool, i, 0)) + continue; + if (ttm_pool_uses_dma_alloc(pool)) + seq_puts(m, "DMA "); + else + seq_printf(m, "N%d ", pool->nid); + 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, + .nr_to_scan = TTM_SHRINKER_BATCH, + }; + unsigned long count; + + fs_reclaim_acquire(GFP_KERNEL); + count = ttm_pool_shrinker_count(mm_shrinker, &sc); + seq_printf(m, "%lu/%lu\n", count, + 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 < NR_PAGE_ORDERS; ++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); +#ifdef CONFIG_FAULT_INJECTION + fault_create_debugfs_attr("backup_fault_inject", ttm_debugfs_root, + &backup_fault_inject); +#endif +#endif + + mm_shrinker = shrinker_alloc(0, "drm-ttm_pool"); + if (!mm_shrinker) + return -ENOMEM; + + mm_shrinker->count_objects = ttm_pool_shrinker_count; + mm_shrinker->scan_objects = ttm_pool_shrinker_scan; + mm_shrinker->batch = TTM_SHRINKER_BATCH; + mm_shrinker->seeks = 1; + + shrinker_register(mm_shrinker); + + return 0; +} + +/** + * 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 < NR_PAGE_ORDERS; ++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]); + } + + shrinker_free(mm_shrinker); + WARN_ON(!list_empty(&shrinker_list)); +} |