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- /*
- * SWIOTLB-based DMA API implementation
- *
- * Copyright (C) 2012 ARM Ltd.
- * Author: Catalin Marinas <catalin.marinas@arm.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
- #include <linux/gfp.h>
- #include <linux/export.h>
- #include <linux/slab.h>
- #include <linux/genalloc.h>
- #include <linux/dma-mapping.h>
- #include <linux/dma-contiguous.h>
- #include <linux/vmalloc.h>
- #include <linux/swiotlb.h>
- #include <asm/cacheflush.h>
- struct dma_map_ops *dma_ops;
- EXPORT_SYMBOL(dma_ops);
- static pgprot_t __get_dma_pgprot(struct dma_attrs *attrs, pgprot_t prot,
- bool coherent)
- {
- if (!coherent || dma_get_attr(DMA_ATTR_WRITE_COMBINE, attrs))
- return pgprot_writecombine(prot);
- return prot;
- }
- static struct gen_pool *atomic_pool;
- #define DEFAULT_DMA_COHERENT_POOL_SIZE SZ_256K
- static size_t atomic_pool_size = DEFAULT_DMA_COHERENT_POOL_SIZE;
- 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 *__alloc_from_pool(size_t size, struct page **ret_page, gfp_t flags)
- {
- unsigned long val;
- void *ptr = NULL;
- if (!atomic_pool) {
- WARN(1, "coherent pool not initialised!\n");
- return NULL;
- }
- val = gen_pool_alloc(atomic_pool, size);
- if (val) {
- phys_addr_t phys = gen_pool_virt_to_phys(atomic_pool, val);
- *ret_page = phys_to_page(phys);
- ptr = (void *)val;
- memset(ptr, 0, size);
- }
- return ptr;
- }
- static bool __in_atomic_pool(void *start, size_t size)
- {
- return addr_in_gen_pool(atomic_pool, (unsigned long)start, size);
- }
- static int __free_from_pool(void *start, size_t size)
- {
- if (!__in_atomic_pool(start, size))
- return 0;
- gen_pool_free(atomic_pool, (unsigned long)start, size);
- return 1;
- }
- static void *__dma_alloc_coherent(struct device *dev, size_t size,
- dma_addr_t *dma_handle, gfp_t flags,
- struct dma_attrs *attrs)
- {
- if (dev == NULL) {
- WARN_ONCE(1, "Use an actual device structure for DMA allocation\n");
- return NULL;
- }
- if (IS_ENABLED(CONFIG_ZONE_DMA) &&
- dev->coherent_dma_mask <= DMA_BIT_MASK(32))
- flags |= GFP_DMA;
- if (IS_ENABLED(CONFIG_DMA_CMA) && (flags & __GFP_WAIT)) {
- struct page *page;
- void *addr;
- page = dma_alloc_from_contiguous(dev, size >> PAGE_SHIFT,
- get_order(size));
- if (!page)
- return NULL;
- *dma_handle = phys_to_dma(dev, page_to_phys(page));
- addr = page_address(page);
- memset(addr, 0, size);
- return addr;
- } else {
- return swiotlb_alloc_coherent(dev, size, dma_handle, flags);
- }
- }
- static void __dma_free_coherent(struct device *dev, size_t size,
- void *vaddr, dma_addr_t dma_handle,
- struct dma_attrs *attrs)
- {
- bool freed;
- phys_addr_t paddr = dma_to_phys(dev, dma_handle);
- if (dev == NULL) {
- WARN_ONCE(1, "Use an actual device structure for DMA allocation\n");
- return;
- }
- freed = dma_release_from_contiguous(dev,
- phys_to_page(paddr),
- size >> PAGE_SHIFT);
- if (!freed)
- swiotlb_free_coherent(dev, size, vaddr, dma_handle);
- }
- static void *__dma_alloc(struct device *dev, size_t size,
- dma_addr_t *dma_handle, gfp_t flags,
- struct dma_attrs *attrs)
- {
- struct page *page;
- void *ptr, *coherent_ptr;
- bool coherent = is_device_dma_coherent(dev);
- size = PAGE_ALIGN(size);
- if (!coherent && !(flags & __GFP_WAIT)) {
- struct page *page = NULL;
- void *addr = __alloc_from_pool(size, &page, flags);
- if (addr)
- *dma_handle = phys_to_dma(dev, page_to_phys(page));
- return addr;
- }
- ptr = __dma_alloc_coherent(dev, size, dma_handle, flags, attrs);
- if (!ptr)
- goto no_mem;
- /* no need for non-cacheable mapping if coherent */
- if (coherent)
- return ptr;
- /* remove any dirty cache lines on the kernel alias */
- __dma_flush_range(ptr, ptr + size);
- /* create a coherent mapping */
- page = virt_to_page(ptr);
- coherent_ptr = dma_common_contiguous_remap(page, size, VM_USERMAP,
- __get_dma_pgprot(attrs,
- __pgprot(PROT_NORMAL_NC), false),
- NULL);
- if (!coherent_ptr)
- goto no_map;
- return coherent_ptr;
- no_map:
- __dma_free_coherent(dev, size, ptr, *dma_handle, attrs);
- no_mem:
- *dma_handle = DMA_ERROR_CODE;
- return NULL;
- }
- static void __dma_free(struct device *dev, size_t size,
- void *vaddr, dma_addr_t dma_handle,
- struct dma_attrs *attrs)
- {
- void *swiotlb_addr = phys_to_virt(dma_to_phys(dev, dma_handle));
- size = PAGE_ALIGN(size);
- if (!is_device_dma_coherent(dev)) {
- if (__free_from_pool(vaddr, size))
- return;
- vunmap(vaddr);
- }
- __dma_free_coherent(dev, size, swiotlb_addr, dma_handle, attrs);
- }
- static dma_addr_t __swiotlb_map_page(struct device *dev, struct page *page,
- unsigned long offset, size_t size,
- enum dma_data_direction dir,
- struct dma_attrs *attrs)
- {
- dma_addr_t dev_addr;
- dev_addr = swiotlb_map_page(dev, page, offset, size, dir, attrs);
- if (!is_device_dma_coherent(dev))
- __dma_map_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
- return dev_addr;
- }
- static void __swiotlb_unmap_page(struct device *dev, dma_addr_t dev_addr,
- size_t size, enum dma_data_direction dir,
- struct dma_attrs *attrs)
- {
- if (!is_device_dma_coherent(dev))
- __dma_unmap_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
- swiotlb_unmap_page(dev, dev_addr, size, dir, attrs);
- }
- static int __swiotlb_map_sg_attrs(struct device *dev, struct scatterlist *sgl,
- int nelems, enum dma_data_direction dir,
- struct dma_attrs *attrs)
- {
- struct scatterlist *sg;
- int i, ret;
- ret = swiotlb_map_sg_attrs(dev, sgl, nelems, dir, attrs);
- if (!is_device_dma_coherent(dev))
- for_each_sg(sgl, sg, ret, i)
- __dma_map_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
- sg->length, dir);
- return ret;
- }
- static void __swiotlb_unmap_sg_attrs(struct device *dev,
- struct scatterlist *sgl, int nelems,
- enum dma_data_direction dir,
- struct dma_attrs *attrs)
- {
- struct scatterlist *sg;
- int i;
- if (!is_device_dma_coherent(dev))
- for_each_sg(sgl, sg, nelems, i)
- __dma_unmap_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
- sg->length, dir);
- swiotlb_unmap_sg_attrs(dev, sgl, nelems, dir, attrs);
- }
- static void __swiotlb_sync_single_for_cpu(struct device *dev,
- dma_addr_t dev_addr, size_t size,
- enum dma_data_direction dir)
- {
- if (!is_device_dma_coherent(dev))
- __dma_unmap_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
- swiotlb_sync_single_for_cpu(dev, dev_addr, size, dir);
- }
- static void __swiotlb_sync_single_for_device(struct device *dev,
- dma_addr_t dev_addr, size_t size,
- enum dma_data_direction dir)
- {
- swiotlb_sync_single_for_device(dev, dev_addr, size, dir);
- if (!is_device_dma_coherent(dev))
- __dma_map_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir);
- }
- static void __swiotlb_sync_sg_for_cpu(struct device *dev,
- struct scatterlist *sgl, int nelems,
- enum dma_data_direction dir)
- {
- struct scatterlist *sg;
- int i;
- if (!is_device_dma_coherent(dev))
- for_each_sg(sgl, sg, nelems, i)
- __dma_unmap_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
- sg->length, dir);
- swiotlb_sync_sg_for_cpu(dev, sgl, nelems, dir);
- }
- static void __swiotlb_sync_sg_for_device(struct device *dev,
- struct scatterlist *sgl, int nelems,
- enum dma_data_direction dir)
- {
- struct scatterlist *sg;
- int i;
- swiotlb_sync_sg_for_device(dev, sgl, nelems, dir);
- if (!is_device_dma_coherent(dev))
- for_each_sg(sgl, sg, nelems, i)
- __dma_map_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)),
- sg->length, dir);
- }
- /* vma->vm_page_prot must be set appropriately before calling this function */
- static int __dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
- void *cpu_addr, dma_addr_t dma_addr, size_t size)
- {
- int ret = -ENXIO;
- unsigned long nr_vma_pages = (vma->vm_end - vma->vm_start) >>
- PAGE_SHIFT;
- unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
- unsigned long pfn = dma_to_phys(dev, dma_addr) >> PAGE_SHIFT;
- unsigned long off = vma->vm_pgoff;
- if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
- return ret;
- if (off < nr_pages && nr_vma_pages <= (nr_pages - off)) {
- ret = remap_pfn_range(vma, vma->vm_start,
- pfn + off,
- vma->vm_end - vma->vm_start,
- vma->vm_page_prot);
- }
- return ret;
- }
- static int __swiotlb_mmap(struct device *dev,
- struct vm_area_struct *vma,
- void *cpu_addr, dma_addr_t dma_addr, size_t size,
- struct dma_attrs *attrs)
- {
- vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot,
- is_device_dma_coherent(dev));
- return __dma_common_mmap(dev, vma, cpu_addr, dma_addr, size);
- }
- static struct dma_map_ops swiotlb_dma_ops = {
- .alloc = __dma_alloc,
- .free = __dma_free,
- .mmap = __swiotlb_mmap,
- .map_page = __swiotlb_map_page,
- .unmap_page = __swiotlb_unmap_page,
- .map_sg = __swiotlb_map_sg_attrs,
- .unmap_sg = __swiotlb_unmap_sg_attrs,
- .sync_single_for_cpu = __swiotlb_sync_single_for_cpu,
- .sync_single_for_device = __swiotlb_sync_single_for_device,
- .sync_sg_for_cpu = __swiotlb_sync_sg_for_cpu,
- .sync_sg_for_device = __swiotlb_sync_sg_for_device,
- .dma_supported = swiotlb_dma_supported,
- .mapping_error = swiotlb_dma_mapping_error,
- };
- static int __init atomic_pool_init(void)
- {
- pgprot_t prot = __pgprot(PROT_NORMAL_NC);
- unsigned long nr_pages = atomic_pool_size >> PAGE_SHIFT;
- struct page *page;
- void *addr;
- unsigned int pool_size_order = get_order(atomic_pool_size);
- if (dev_get_cma_area(NULL))
- page = dma_alloc_from_contiguous(NULL, nr_pages,
- pool_size_order);
- else
- page = alloc_pages(GFP_DMA, pool_size_order);
- if (page) {
- int ret;
- void *page_addr = page_address(page);
- memset(page_addr, 0, atomic_pool_size);
- __dma_flush_range(page_addr, page_addr + atomic_pool_size);
- atomic_pool = gen_pool_create(PAGE_SHIFT, -1);
- if (!atomic_pool)
- goto free_page;
- addr = dma_common_contiguous_remap(page, atomic_pool_size,
- VM_USERMAP, prot, atomic_pool_init);
- if (!addr)
- goto destroy_genpool;
- ret = gen_pool_add_virt(atomic_pool, (unsigned long)addr,
- page_to_phys(page),
- atomic_pool_size, -1);
- if (ret)
- goto remove_mapping;
- gen_pool_set_algo(atomic_pool,
- gen_pool_first_fit_order_align,
- (void *)PAGE_SHIFT);
- pr_info("DMA: preallocated %zu KiB pool for atomic allocations\n",
- atomic_pool_size / 1024);
- return 0;
- }
- goto out;
- remove_mapping:
- dma_common_free_remap(addr, atomic_pool_size, VM_USERMAP);
- destroy_genpool:
- gen_pool_destroy(atomic_pool);
- atomic_pool = NULL;
- free_page:
- if (!dma_release_from_contiguous(NULL, page, nr_pages))
- __free_pages(page, pool_size_order);
- out:
- pr_err("DMA: failed to allocate %zu KiB pool for atomic coherent allocation\n",
- atomic_pool_size / 1024);
- return -ENOMEM;
- }
- static int __init arm64_dma_init(void)
- {
- int ret;
- dma_ops = &swiotlb_dma_ops;
- ret = atomic_pool_init();
- return ret;
- }
- arch_initcall(arm64_dma_init);
- #define PREALLOC_DMA_DEBUG_ENTRIES 4096
- static int __init dma_debug_do_init(void)
- {
- dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
- return 0;
- }
- fs_initcall(dma_debug_do_init);
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