// SPDX-License-Identifier: GPL-2.0 /* * ION Memory Allocator page pool helpers * * Copyright (C) 2011 Google, Inc. */ #include #include #include #include #include "ion.h" static inline struct page *ion_page_pool_alloc_pages(struct ion_page_pool *pool) { if (fatal_signal_pending(current)) return NULL; return alloc_pages(pool->gfp_mask, pool->order); } static void ion_page_pool_free_pages(struct ion_page_pool *pool, struct page *page) { __free_pages(page, pool->order); } static void ion_page_pool_add(struct ion_page_pool *pool, struct page *page) { mutex_lock(&pool->mutex); if (PageHighMem(page)) { list_add_tail(&page->lru, &pool->high_items); pool->high_count++; } else { list_add_tail(&page->lru, &pool->low_items); pool->low_count++; } mod_node_page_state(page_pgdat(page), NR_KERNEL_MISC_RECLAIMABLE, 1 << pool->order); mutex_unlock(&pool->mutex); } static struct page *ion_page_pool_remove(struct ion_page_pool *pool, bool high) { struct page *page; if (high) { BUG_ON(!pool->high_count); page = list_first_entry(&pool->high_items, struct page, lru); pool->high_count--; } else { BUG_ON(!pool->low_count); page = list_first_entry(&pool->low_items, struct page, lru); pool->low_count--; } list_del(&page->lru); mod_node_page_state(page_pgdat(page), NR_KERNEL_MISC_RECLAIMABLE, -(1 << pool->order)); return page; } struct page *ion_page_pool_alloc(struct ion_page_pool *pool) { struct page *page = NULL; BUG_ON(!pool); mutex_lock(&pool->mutex); if (pool->high_count) page = ion_page_pool_remove(pool, true); else if (pool->low_count) page = ion_page_pool_remove(pool, false); mutex_unlock(&pool->mutex); if (!page) page = ion_page_pool_alloc_pages(pool); return page; } void ion_page_pool_free(struct ion_page_pool *pool, struct page *page) { BUG_ON(pool->order != compound_order(page)); ion_page_pool_add(pool, page); } static int ion_page_pool_total(struct ion_page_pool *pool, bool high) { int count = pool->low_count; if (high) count += pool->high_count; return count << pool->order; } int ion_page_pool_shrink(struct ion_page_pool *pool, gfp_t gfp_mask, int nr_to_scan) { int freed = 0; bool high; if (current_is_kswapd()) high = true; else high = !!(gfp_mask & __GFP_HIGHMEM); if (nr_to_scan == 0) return ion_page_pool_total(pool, high); while (freed < nr_to_scan) { struct page *page; mutex_lock(&pool->mutex); if (pool->low_count) { page = ion_page_pool_remove(pool, false); } else if (high && pool->high_count) { page = ion_page_pool_remove(pool, true); } else { mutex_unlock(&pool->mutex); break; } mutex_unlock(&pool->mutex); ion_page_pool_free_pages(pool, page); freed += (1 << pool->order); } return freed; } struct ion_page_pool *ion_page_pool_create(gfp_t gfp_mask, unsigned int order) { struct ion_page_pool *pool = kmalloc(sizeof(*pool), GFP_KERNEL); if (!pool) return NULL; pool->high_count = 0; pool->low_count = 0; INIT_LIST_HEAD(&pool->low_items); INIT_LIST_HEAD(&pool->high_items); pool->gfp_mask = gfp_mask | __GFP_COMP; pool->order = order; mutex_init(&pool->mutex); plist_node_init(&pool->list, order); return pool; } void ion_page_pool_destroy(struct ion_page_pool *pool) { kfree(pool); }