This adds a shrinker controlled page pool, extracted out of the ttm_pool logic, and abstracted out a bit so it can be used by other non-ttm drivers.
Cc: Daniel Vetter daniel@ffwll.ch Cc: Christian Koenig christian.koenig@amd.com Cc: Sumit Semwal sumit.semwal@linaro.org Cc: Liam Mark lmark@codeaurora.org Cc: Chris Goldsworthy cgoldswo@codeaurora.org Cc: Laura Abbott labbott@kernel.org Cc: Brian Starkey Brian.Starkey@arm.com Cc: Hridya Valsaraju hridya@google.com Cc: Suren Baghdasaryan surenb@google.com Cc: Sandeep Patil sspatil@google.com Cc: Daniel Mentz danielmentz@google.com Cc: Ørjan Eide orjan.eide@arm.com Cc: Robin Murphy robin.murphy@arm.com Cc: Ezequiel Garcia ezequiel@collabora.com Cc: Simon Ser contact@emersion.fr Cc: James Jones jajones@nvidia.com Cc: linux-media@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Signed-off-by: John Stultz john.stultz@linaro.org --- v8: * Completely rewritten from scratch, using only the ttm_pool logic so it can be dual licensed. --- drivers/gpu/drm/Kconfig | 4 + drivers/gpu/drm/Makefile | 2 + drivers/gpu/drm/page_pool.c | 214 ++++++++++++++++++++++++++++++++++++ include/drm/page_pool.h | 65 +++++++++++ 4 files changed, 285 insertions(+) create mode 100644 drivers/gpu/drm/page_pool.c create mode 100644 include/drm/page_pool.h
diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig index e392a90ca687..7cbcecb8f7df 100644 --- a/drivers/gpu/drm/Kconfig +++ b/drivers/gpu/drm/Kconfig @@ -177,6 +177,10 @@ config DRM_DP_CEC Note: not all adapters support this feature, and even for those that do support this they often do not hook up the CEC pin.
+config DRM_PAGE_POOL + bool + depends on DRM + config DRM_TTM tristate depends on DRM && MMU diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile index 926adef289db..2dc7b2fe3fe5 100644 --- a/drivers/gpu/drm/Makefile +++ b/drivers/gpu/drm/Makefile @@ -39,6 +39,8 @@ obj-$(CONFIG_DRM_VRAM_HELPER) += drm_vram_helper.o drm_ttm_helper-y := drm_gem_ttm_helper.o obj-$(CONFIG_DRM_TTM_HELPER) += drm_ttm_helper.o
+drm-$(CONFIG_DRM_PAGE_POOL) += page_pool.o + drm_kms_helper-y := drm_bridge_connector.o drm_crtc_helper.o drm_dp_helper.o \ drm_dsc.o drm_probe_helper.o \ drm_plane_helper.o drm_dp_mst_topology.o drm_atomic_helper.o \ diff --git a/drivers/gpu/drm/page_pool.c b/drivers/gpu/drm/page_pool.c new file mode 100644 index 000000000000..a60b954cfe0f --- /dev/null +++ b/drivers/gpu/drm/page_pool.c @@ -0,0 +1,214 @@ +// SPDX-License-Identifier: GPL-2.0 OR MIT +/* + * Sharable page pool implementation + * + * Extracted from drivers/gpu/drm/ttm/ttm_pool.c + * Copyright 2020 Advanced Micro Devices, Inc. + * Copyright 2021 Linaro Ltd. + * + * 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, John Stultz + */ + +#include <linux/module.h> +#include <linux/highmem.h> +#include <linux/shrinker.h> +#include <drm/page_pool.h> + +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 mutex shrinker_lock; +static struct list_head shrinker_list; +static struct shrinker mm_shrinker; + +void drm_page_pool_set_max(unsigned long max) +{ + if (!page_pool_size) + page_pool_size = max; +} + +unsigned long drm_page_pool_get_max(void) +{ + return page_pool_size; +} + +unsigned long drm_page_pool_get_total(void) +{ + return atomic_long_read(&allocated_pages); +} + +unsigned long drm_page_pool_get_size(struct drm_page_pool *pool) +{ + unsigned long size; + + spin_lock(&pool->lock); + size = pool->page_count; + spin_unlock(&pool->lock); + return size; +} + +/* Give pages into a specific pool */ +void drm_page_pool_add(struct drm_page_pool *pool, struct page *p) +{ + unsigned int i, num_pages = 1 << pool->order; + + for (i = 0; i < num_pages; ++i) { + if (PageHighMem(p)) + clear_highpage(p + i); + else + clear_page(page_address(p + i)); + } + + spin_lock(&pool->lock); + list_add(&p->lru, &pool->pages); + pool->page_count += 1 << pool->order; + spin_unlock(&pool->lock); + atomic_long_add(1 << pool->order, &allocated_pages); +} + +/* Take pages from a specific pool, return NULL when nothing available */ +struct page *drm_page_pool_remove(struct drm_page_pool *pool) +{ + struct page *p; + + spin_lock(&pool->lock); + p = list_first_entry_or_null(&pool->pages, typeof(*p), lru); + if (p) { + atomic_long_sub(1 << pool->order, &allocated_pages); + pool->page_count -= 1 << pool->order; + list_del(&p->lru); + } + spin_unlock(&pool->lock); + + return p; +} + +/* Initialize and add a pool type to the global shrinker list */ +void drm_page_pool_init(struct drm_page_pool *pool, unsigned int order, + unsigned long (*free_page)(struct drm_page_pool *pool, struct page *p)) +{ + pool->order = order; + spin_lock_init(&pool->lock); + INIT_LIST_HEAD(&pool->pages); + pool->free = free_page; + pool->page_count = 0; + + mutex_lock(&shrinker_lock); + list_add_tail(&pool->shrinker_list, &shrinker_list); + mutex_unlock(&shrinker_lock); +} + +/* Remove a pool_type from the global shrinker list and free all pages */ +void drm_page_pool_fini(struct drm_page_pool *pool) +{ + struct page *p, *tmp; + + mutex_lock(&shrinker_lock); + list_del(&pool->shrinker_list); + mutex_unlock(&shrinker_lock); + + list_for_each_entry_safe(p, tmp, &pool->pages, lru) + pool->free(pool, p); +} + +/* Free pages using the global shrinker list */ +static unsigned int drm_page_pool_shrink(void) +{ + struct drm_page_pool *pool; + unsigned int num_freed; + struct page *p; + + mutex_lock(&shrinker_lock); + pool = list_first_entry(&shrinker_list, typeof(*pool), shrinker_list); + + p = drm_page_pool_remove(pool); + + list_move_tail(&pool->shrinker_list, &shrinker_list); + mutex_unlock(&shrinker_lock); + + if (p) { + pool->free(pool, p); + num_freed = 1 << pool->order; + } else { + num_freed = 0; + } + + return num_freed; +} + +/* As long as pages are available make sure to release at least one */ +static unsigned long drm_page_pool_shrinker_scan(struct shrinker *shrink, + struct shrink_control *sc) +{ + unsigned long num_freed = 0; + + do + num_freed += drm_page_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 drm_page_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; +} + +/** + * drm_page_pool_shrinker_setup - Initialize globals + * + * @num_pages: default number of pages + * + * Initialize the global locks and lists for the shrinker. + */ +int drm_page_pool_shrinker_setup(void) +{ + mutex_init(&shrinker_lock); + INIT_LIST_HEAD(&shrinker_list); + + mm_shrinker.count_objects = drm_page_pool_shrinker_count; + mm_shrinker.scan_objects = drm_page_pool_shrinker_scan; + mm_shrinker.seeks = 1; + return register_shrinker(&mm_shrinker); +} + +/** + * drm_page_pool_shrinker_teardown - Finalize globals + * + * Unregister the shrinker. + */ +void drm_page_pool_shrinker_teardown(void) +{ + unregister_shrinker(&mm_shrinker); + WARN_ON(!list_empty(&shrinker_list)); +} + +module_init(drm_page_pool_shrinker_setup); +module_exit(drm_page_pool_shrinker_teardown); +MODULE_LICENSE("Dual MIT/GPL"); diff --git a/include/drm/page_pool.h b/include/drm/page_pool.h new file mode 100644 index 000000000000..d8b8a8415629 --- /dev/null +++ b/include/drm/page_pool.h @@ -0,0 +1,65 @@ +/* SPDX-License-Identifier: GPL-2.0 OR MIT */ +/* + * Extracted from include/drm/ttm/ttm_pool.h + * Copyright 2020 Advanced Micro Devices, Inc. + * Copyright 2021 Linaro Ltd + * + * 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, John Stultz + */ + +#ifndef _DRM_PAGE_POOL_H_ +#define _DRM_PAGE_POOL_H_ + +#include <linux/mmzone.h> +#include <linux/llist.h> +#include <linux/spinlock.h> + +/** + * drm_page_pool - Page Pool for a certain memory type + * + * @order: the allocation order our pages have + * @pages: the list of pages in the pool + * @shrinker_list: our place on the global shrinker list + * @lock: protection of the page list + * @page_count: number of pages currently in the pool + * @free: Function pointer to free the page + */ +struct drm_page_pool { + unsigned int order; + struct list_head pages; + struct list_head shrinker_list; + spinlock_t lock; + + unsigned long page_count; + unsigned long (*free)(struct drm_page_pool *pool, struct page *p); +}; + +void drm_page_pool_set_max(unsigned long max); +unsigned long drm_page_pool_get_max(void); +unsigned long drm_page_pool_get_total(void); +unsigned long drm_page_pool_get_size(struct drm_page_pool *pool); +void drm_page_pool_add(struct drm_page_pool *pool, struct page *p); +struct page *drm_page_pool_remove(struct drm_page_pool *pool); +void drm_page_pool_init(struct drm_page_pool *pool, unsigned int order, + unsigned long (*free_page)(struct drm_page_pool *pool, struct page *p)); +void drm_page_pool_fini(struct drm_page_pool *pool); + +#endif