// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2012 ARM Ltd. * Copyright (C) 2020 Google LLC */ #include #include #include #include #include #include #include #include #include #include struct dma_gen_pool { bool cc_shared; struct gen_pool *pool; }; static struct dma_gen_pool atomic_pool_dma __ro_after_init; static unsigned long pool_size_dma; static struct dma_gen_pool atomic_pool_dma32 __ro_after_init; static unsigned long pool_size_dma32; static struct dma_gen_pool atomic_pool_kernel __ro_after_init; static unsigned long pool_size_kernel; /* Size can be defined by the coherent_pool command line */ static size_t atomic_pool_size; /* Dynamic background expansion when the atomic pool is near capacity */ static struct work_struct atomic_pool_work; static int __init early_coherent_pool(char *p) { atomic_pool_size = memparse(p, &p); return 0; } early_param("coherent_pool", early_coherent_pool); static void __init dma_atomic_pool_debugfs_init(void) { struct dentry *root; root = debugfs_create_dir("dma_pools", NULL); debugfs_create_ulong("pool_size_dma", 0400, root, &pool_size_dma); debugfs_create_ulong("pool_size_dma32", 0400, root, &pool_size_dma32); debugfs_create_ulong("pool_size_kernel", 0400, root, &pool_size_kernel); } static void dma_atomic_pool_size_add(gfp_t gfp, size_t size) { if (gfp & __GFP_DMA) pool_size_dma += size; else if (gfp & __GFP_DMA32) pool_size_dma32 += size; else pool_size_kernel += size; } static bool cma_in_zone(gfp_t gfp) { unsigned long size; phys_addr_t end; struct cma *cma; cma = dev_get_cma_area(NULL); if (!cma) return false; size = cma_get_size(cma); if (!size) return false; /* CMA can't cross zone boundaries, see cma_activate_area() */ end = cma_get_base(cma) + size - 1; if (IS_ENABLED(CONFIG_ZONE_DMA) && (gfp & GFP_DMA)) return end <= zone_dma_limit; if (IS_ENABLED(CONFIG_ZONE_DMA32) && (gfp & GFP_DMA32)) return end <= max(DMA_BIT_MASK(32), zone_dma_limit); return true; } static int atomic_pool_expand(struct dma_gen_pool *dma_pool, size_t pool_size, gfp_t gfp) { unsigned int order; struct page *page = NULL; bool leak_pages = false; void *addr; int ret = -ENOMEM; pgprot_t prot __maybe_unused; /* Cannot allocate larger than MAX_PAGE_ORDER */ order = min(get_order(pool_size), MAX_PAGE_ORDER); do { pool_size = 1 << (PAGE_SHIFT + order); if (cma_in_zone(gfp)) page = dma_alloc_from_contiguous(NULL, 1 << order, order, false); if (!page) page = alloc_pages(gfp | __GFP_NOWARN, order); } while (!page && order-- > 0); if (!page) goto out; arch_dma_prep_coherent(page, pool_size); #ifdef CONFIG_DMA_DIRECT_REMAP if (dma_pool->cc_shared) prot = pgprot_decrypted(pgprot_dmacoherent(PAGE_KERNEL)); else prot = pgprot_dmacoherent(PAGE_KERNEL); addr = dma_common_contiguous_remap(page, pool_size, prot, __builtin_return_address(0)); if (!addr) goto free_page; #else addr = page_to_virt(page); #endif /* * Memory in the atomic DMA pools must be unencrypted, the pools do not * shrink so no re-encryption occurs in dma_direct_free(). */ if (dma_pool->cc_shared) { ret = set_memory_decrypted((unsigned long)page_to_virt(page), 1 << order); if (ret) { leak_pages = true; goto remove_mapping; } } ret = gen_pool_add_virt(dma_pool->pool, (unsigned long)addr, page_to_phys(page), pool_size, NUMA_NO_NODE); if (ret) goto encrypt_mapping; dma_atomic_pool_size_add(gfp, pool_size); return 0; encrypt_mapping: if (dma_pool->cc_shared && set_memory_encrypted((unsigned long)page_to_virt(page), 1 << order)) leak_pages = true; remove_mapping: #ifdef CONFIG_DMA_DIRECT_REMAP dma_common_free_remap(addr, pool_size); free_page: #endif if (!leak_pages) __free_pages(page, order); out: return ret; } static void atomic_pool_resize(struct dma_gen_pool *dma_pool, gfp_t gfp) { if (dma_pool->pool && gen_pool_avail(dma_pool->pool) < atomic_pool_size) atomic_pool_expand(dma_pool, gen_pool_size(dma_pool->pool), gfp); } static void atomic_pool_work_fn(struct work_struct *work) { if (IS_ENABLED(CONFIG_ZONE_DMA)) atomic_pool_resize(&atomic_pool_dma, GFP_KERNEL | GFP_DMA); if (IS_ENABLED(CONFIG_ZONE_DMA32)) atomic_pool_resize(&atomic_pool_dma32, GFP_KERNEL | GFP_DMA32); atomic_pool_resize(&atomic_pool_kernel, GFP_KERNEL); } static __init struct dma_gen_pool *__dma_atomic_pool_init(struct dma_gen_pool *dma_pool, size_t pool_size, gfp_t gfp) { int ret; dma_pool->pool = gen_pool_create(PAGE_SHIFT, NUMA_NO_NODE); if (!dma_pool->pool) return NULL; gen_pool_set_algo(dma_pool->pool, gen_pool_first_fit_order_align, NULL); /* if platform is using memory encryption atomic pools are by default shared. */ if (cc_platform_has(CC_ATTR_MEM_ENCRYPT)) dma_pool->cc_shared = true; else dma_pool->cc_shared = false; ret = atomic_pool_expand(dma_pool, pool_size, gfp); if (ret) { gen_pool_destroy(dma_pool->pool); dma_pool->pool = NULL; pr_err("DMA: failed to allocate %zu KiB %pGg pool for atomic allocation\n", pool_size >> 10, &gfp); return NULL; } pr_info("DMA: preallocated %zu KiB %pGg pool for atomic allocations\n", gen_pool_size(dma_pool->pool) >> 10, &gfp); return dma_pool; } #ifdef CONFIG_ZONE_DMA32 #define has_managed_dma32 has_managed_zone(ZONE_DMA32) #else #define has_managed_dma32 false #endif static int __init dma_atomic_pool_init(void) { int ret = 0; /* * If coherent_pool was not used on the command line, default the pool * sizes to 128KB per 1GB of memory, min 128KB, max MAX_PAGE_ORDER. */ if (!atomic_pool_size) { unsigned long pages = totalram_pages() / (SZ_1G / SZ_128K); pages = min_t(unsigned long, pages, MAX_ORDER_NR_PAGES); atomic_pool_size = max_t(size_t, pages << PAGE_SHIFT, SZ_128K); } INIT_WORK(&atomic_pool_work, atomic_pool_work_fn); /* All memory might be in the DMA zone(s) to begin with */ if (has_managed_zone(ZONE_NORMAL)) { __dma_atomic_pool_init(&atomic_pool_kernel, atomic_pool_size, GFP_KERNEL); if (!atomic_pool_kernel.pool) ret = -ENOMEM; } if (has_managed_dma()) { __dma_atomic_pool_init(&atomic_pool_dma, atomic_pool_size, GFP_KERNEL | GFP_DMA); if (!atomic_pool_dma.pool) ret = -ENOMEM; } if (has_managed_dma32) { __dma_atomic_pool_init(&atomic_pool_dma32, atomic_pool_size, GFP_KERNEL | GFP_DMA32); if (!atomic_pool_dma32.pool) ret = -ENOMEM; } dma_atomic_pool_debugfs_init(); return ret; } postcore_initcall(dma_atomic_pool_init); static inline struct dma_gen_pool *__dma_guess_pool(struct dma_gen_pool *first, struct dma_gen_pool *second, struct dma_gen_pool *third) { if (first->pool) return first; if (second && second->pool) return second; if (third && third->pool) return third; return NULL; } static inline struct dma_gen_pool *dma_guess_pool(struct dma_gen_pool *prev, gfp_t gfp) { if (!prev) { if (gfp & GFP_DMA) return __dma_guess_pool(&atomic_pool_dma, &atomic_pool_dma32, &atomic_pool_kernel); if (gfp & GFP_DMA32) return __dma_guess_pool(&atomic_pool_dma32, &atomic_pool_dma, &atomic_pool_kernel); return __dma_guess_pool(&atomic_pool_kernel, &atomic_pool_dma32, &atomic_pool_dma); } if (prev == &atomic_pool_kernel) return __dma_guess_pool(&atomic_pool_dma32, &atomic_pool_dma, NULL); if (prev == &atomic_pool_dma32) return __dma_guess_pool(&atomic_pool_dma, NULL, NULL); return NULL; } static struct page *__dma_alloc_from_pool(struct device *dev, size_t size, struct gen_pool *pool, void **cpu_addr, bool (*phys_addr_ok)(struct device *, phys_addr_t, size_t)) { unsigned long addr; phys_addr_t phys; addr = gen_pool_alloc(pool, size); if (!addr) return NULL; phys = gen_pool_virt_to_phys(pool, addr); if (phys_addr_ok && !phys_addr_ok(dev, phys, size)) { gen_pool_free(pool, addr, size); return NULL; } if (gen_pool_avail(pool) < atomic_pool_size) schedule_work(&atomic_pool_work); *cpu_addr = (void *)addr; memset(*cpu_addr, 0, size); return pfn_to_page(__phys_to_pfn(phys)); } struct page *dma_alloc_from_pool(struct device *dev, size_t size, void **cpu_addr, gfp_t gfp, unsigned long attrs, bool (*phys_addr_ok)(struct device *, phys_addr_t, size_t)) { struct dma_gen_pool *dma_pool = NULL; struct page *page; bool pool_found = false; while ((dma_pool = dma_guess_pool(dma_pool, gfp))) { if (dma_pool->cc_shared != !!(attrs & __DMA_ATTR_ALLOC_CC_SHARED)) continue; pool_found = true; page = __dma_alloc_from_pool(dev, size, dma_pool->pool, cpu_addr, phys_addr_ok); if (page) return page; } if (pool_found) WARN(!(gfp & __GFP_NOWARN), "DMA pool exhausted for %s\n", dev_name(dev)); else WARN(1, "Failed to get suitable pool for %s\n", dev_name(dev)); return NULL; } bool dma_free_from_pool(struct device *dev, void *start, size_t size) { struct dma_gen_pool *dma_pool = NULL; while ((dma_pool = dma_guess_pool(dma_pool, 0))) { if (!gen_pool_has_addr(dma_pool->pool, (unsigned long)start, size)) continue; gen_pool_free(dma_pool->pool, (unsigned long)start, size); return true; } return false; } struct dma_pool_phys_match { phys_addr_t phys; size_t size; unsigned long addr; bool found; }; static void dma_pool_find_phys(struct gen_pool *pool, struct gen_pool_chunk *chunk, void *data) { struct dma_pool_phys_match *match = data; phys_addr_t end = match->phys + match->size - 1; phys_addr_t chunk_end; if (match->found) return; chunk_end = chunk->phys_addr + (chunk->end_addr - chunk->start_addr); if (match->phys < chunk->phys_addr || end > chunk_end) return; match->addr = chunk->start_addr + (match->phys - chunk->phys_addr); match->found = true; } static bool dma_free_from_pool_phys(struct dma_gen_pool *dma_pool, phys_addr_t phys, size_t size) { struct dma_pool_phys_match match = { .phys = phys, .size = size, }; gen_pool_for_each_chunk(dma_pool->pool, dma_pool_find_phys, &match); if (!match.found) return false; gen_pool_free(dma_pool->pool, match.addr, size); return true; } /* * FIXME: We could avoid this by storing the remapped virtual address in * struct page and using that for lookup. */ bool dma_free_from_pool_page(struct device *dev, struct page *page, size_t size) { struct dma_gen_pool *dma_pool = NULL; phys_addr_t phys = page_to_phys(page); if (!IS_ENABLED(CONFIG_DMA_DIRECT_REMAP)) return dma_free_from_pool(dev, page_address(page), size); while ((dma_pool = dma_guess_pool(dma_pool, 0))) { if (dma_free_from_pool_phys(dma_pool, phys, size)) return true; } return false; }