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Diffstat (limited to '')
| -rw-r--r-- | kernel/dma/pool.c | 298 |
1 files changed, 298 insertions, 0 deletions
diff --git a/kernel/dma/pool.c b/kernel/dma/pool.c new file mode 100644 index 000000000..b9082b572 --- /dev/null +++ b/kernel/dma/pool.c @@ -0,0 +1,298 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2012 ARM Ltd. + * Copyright (C) 2020 Google LLC + */ +#include <linux/cma.h> +#include <linux/debugfs.h> +#include <linux/dma-map-ops.h> +#include <linux/dma-direct.h> +#include <linux/init.h> +#include <linux/genalloc.h> +#include <linux/set_memory.h> +#include <linux/slab.h> +#include <linux/workqueue.h> + +static struct gen_pool *atomic_pool_dma __ro_after_init; +static unsigned long pool_size_dma; +static struct gen_pool *atomic_pool_dma32 __ro_after_init; +static unsigned long pool_size_dma32; +static struct 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); + if (IS_ERR_OR_NULL(root)) + return; + + 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 <= DMA_BIT_MASK(zone_dma_bits); + if (IS_ENABLED(CONFIG_ZONE_DMA32) && (gfp & GFP_DMA32)) + return end <= DMA_BIT_MASK(32); + return true; +} + +static int atomic_pool_expand(struct gen_pool *pool, size_t pool_size, + gfp_t gfp) +{ + unsigned int order; + struct page *page = NULL; + void *addr; + int ret = -ENOMEM; + + /* Cannot allocate larger than MAX_ORDER-1 */ + order = min(get_order(pool_size), MAX_ORDER-1); + + 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, order); + } while (!page && order-- > 0); + if (!page) + goto out; + + arch_dma_prep_coherent(page, pool_size); + +#ifdef CONFIG_DMA_DIRECT_REMAP + addr = dma_common_contiguous_remap(page, pool_size, + pgprot_dmacoherent(PAGE_KERNEL), + __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(). + */ + ret = set_memory_decrypted((unsigned long)page_to_virt(page), + 1 << order); + if (ret) + goto remove_mapping; + ret = gen_pool_add_virt(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: + ret = set_memory_encrypted((unsigned long)page_to_virt(page), + 1 << order); + if (WARN_ON_ONCE(ret)) { + /* Decrypt succeeded but encrypt failed, purposely leak */ + goto out; + } +remove_mapping: +#ifdef CONFIG_DMA_DIRECT_REMAP + dma_common_free_remap(addr, pool_size); +#endif +free_page: __maybe_unused + __free_pages(page, order); +out: + return ret; +} + +static void atomic_pool_resize(struct gen_pool *pool, gfp_t gfp) +{ + if (pool && gen_pool_avail(pool) < atomic_pool_size) + atomic_pool_expand(pool, gen_pool_size(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 gen_pool *__dma_atomic_pool_init(size_t pool_size, + gfp_t gfp) +{ + struct gen_pool *pool; + int ret; + + pool = gen_pool_create(PAGE_SHIFT, NUMA_NO_NODE); + if (!pool) + return NULL; + + gen_pool_set_algo(pool, gen_pool_first_fit_order_align, NULL); + + ret = atomic_pool_expand(pool, pool_size, gfp); + if (ret) { + gen_pool_destroy(pool); + 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(pool) >> 10, &gfp); + return pool; +} + +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_ORDER-1. + */ + 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); + + atomic_pool_kernel = __dma_atomic_pool_init(atomic_pool_size, + GFP_KERNEL); + if (!atomic_pool_kernel) + ret = -ENOMEM; + if (has_managed_dma()) { + atomic_pool_dma = __dma_atomic_pool_init(atomic_pool_size, + GFP_KERNEL | GFP_DMA); + if (!atomic_pool_dma) + ret = -ENOMEM; + } + if (IS_ENABLED(CONFIG_ZONE_DMA32)) { + atomic_pool_dma32 = __dma_atomic_pool_init(atomic_pool_size, + GFP_KERNEL | GFP_DMA32); + if (!atomic_pool_dma32) + ret = -ENOMEM; + } + + dma_atomic_pool_debugfs_init(); + return ret; +} +postcore_initcall(dma_atomic_pool_init); + +static inline struct gen_pool *dma_guess_pool(struct gen_pool *prev, gfp_t gfp) +{ + if (prev == NULL) { + if (IS_ENABLED(CONFIG_ZONE_DMA32) && (gfp & GFP_DMA32)) + return atomic_pool_dma32; + if (atomic_pool_dma && (gfp & GFP_DMA)) + return atomic_pool_dma; + return atomic_pool_kernel; + } + if (prev == atomic_pool_kernel) + return atomic_pool_dma32 ? atomic_pool_dma32 : atomic_pool_dma; + if (prev == atomic_pool_dma32) + return atomic_pool_dma; + 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, + bool (*phys_addr_ok)(struct device *, phys_addr_t, size_t)) +{ + struct gen_pool *pool = NULL; + struct page *page; + + while ((pool = dma_guess_pool(pool, gfp))) { + page = __dma_alloc_from_pool(dev, size, pool, cpu_addr, + phys_addr_ok); + if (page) + return page; + } + + 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 gen_pool *pool = NULL; + + while ((pool = dma_guess_pool(pool, 0))) { + if (!gen_pool_has_addr(pool, (unsigned long)start, size)) + continue; + gen_pool_free(pool, (unsigned long)start, size); + return true; + } + + return false; +} |