diff options
Diffstat (limited to 'kernel/dma/coherent.c')
-rw-r--r-- | kernel/dma/coherent.c | 214 |
1 files changed, 114 insertions, 100 deletions
diff --git a/kernel/dma/coherent.c b/kernel/dma/coherent.c index 551b0eb7028a..c21abc77c53e 100644 --- a/kernel/dma/coherent.c +++ b/kernel/dma/coherent.c @@ -7,7 +7,8 @@ #include <linux/slab.h> #include <linux/kernel.h> #include <linux/module.h> -#include <linux/dma-mapping.h> +#include <linux/dma-direct.h> +#include <linux/dma-map-ops.h> struct dma_coherent_mem { void *virt_base; @@ -19,8 +20,6 @@ struct dma_coherent_mem { bool use_dev_dma_pfn_offset; }; -static struct dma_coherent_mem *dma_coherent_default_memory __ro_after_init; - static inline struct dma_coherent_mem *dev_get_coherent_memory(struct device *dev) { if (dev && dev->dma_mem) @@ -32,65 +31,56 @@ static inline dma_addr_t dma_get_device_base(struct device *dev, struct dma_coherent_mem * mem) { if (mem->use_dev_dma_pfn_offset) - return (mem->pfn_base - dev->dma_pfn_offset) << PAGE_SHIFT; - else - return mem->device_base; + return phys_to_dma(dev, PFN_PHYS(mem->pfn_base)); + return mem->device_base; } -static int dma_init_coherent_memory(phys_addr_t phys_addr, - dma_addr_t device_addr, size_t size, - struct dma_coherent_mem **mem) +static struct dma_coherent_mem *dma_init_coherent_memory(phys_addr_t phys_addr, + dma_addr_t device_addr, size_t size, bool use_dma_pfn_offset) { - struct dma_coherent_mem *dma_mem = NULL; - void *mem_base = NULL; + struct dma_coherent_mem *dma_mem; int pages = size >> PAGE_SHIFT; - int bitmap_size = BITS_TO_LONGS(pages) * sizeof(long); - int ret; + void *mem_base; - if (!size) { - ret = -EINVAL; - goto out; - } + if (!size) + return ERR_PTR(-EINVAL); mem_base = memremap(phys_addr, size, MEMREMAP_WC); - if (!mem_base) { - ret = -EINVAL; - goto out; - } + if (!mem_base) + return ERR_PTR(-EINVAL); + dma_mem = kzalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL); - if (!dma_mem) { - ret = -ENOMEM; - goto out; - } - dma_mem->bitmap = kzalloc(bitmap_size, GFP_KERNEL); - if (!dma_mem->bitmap) { - ret = -ENOMEM; - goto out; - } + if (!dma_mem) + goto out_unmap_membase; + dma_mem->bitmap = bitmap_zalloc(pages, GFP_KERNEL); + if (!dma_mem->bitmap) + goto out_free_dma_mem; dma_mem->virt_base = mem_base; dma_mem->device_base = device_addr; dma_mem->pfn_base = PFN_DOWN(phys_addr); dma_mem->size = pages; + dma_mem->use_dev_dma_pfn_offset = use_dma_pfn_offset; spin_lock_init(&dma_mem->spinlock); - *mem = dma_mem; - return 0; + return dma_mem; -out: +out_free_dma_mem: kfree(dma_mem); - if (mem_base) - memunmap(mem_base); - return ret; +out_unmap_membase: + memunmap(mem_base); + pr_err("Reserved memory: failed to init DMA memory pool at %pa, size %zd MiB\n", + &phys_addr, size / SZ_1M); + return ERR_PTR(-ENOMEM); } -static void dma_release_coherent_memory(struct dma_coherent_mem *mem) +static void _dma_release_coherent_memory(struct dma_coherent_mem *mem) { if (!mem) return; memunmap(mem->virt_base); - kfree(mem->bitmap); + bitmap_free(mem->bitmap); kfree(mem); } @@ -107,22 +97,45 @@ static int dma_assign_coherent_memory(struct device *dev, return 0; } +/* + * Declare a region of memory to be handed out by dma_alloc_coherent() when it + * is asked for coherent memory for this device. This shall only be used + * from platform code, usually based on the device tree description. + * + * phys_addr is the CPU physical address to which the memory is currently + * assigned (this will be ioremapped so the CPU can access the region). + * + * device_addr is the DMA address the device needs to be programmed with to + * actually address this memory (this will be handed out as the dma_addr_t in + * dma_alloc_coherent()). + * + * size is the size of the area (must be a multiple of PAGE_SIZE). + * + * As a simplification for the platforms, only *one* such region of memory may + * be declared per device. + */ int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr, dma_addr_t device_addr, size_t size) { struct dma_coherent_mem *mem; int ret; - ret = dma_init_coherent_memory(phys_addr, device_addr, size, &mem); - if (ret) - return ret; + mem = dma_init_coherent_memory(phys_addr, device_addr, size, false); + if (IS_ERR(mem)) + return PTR_ERR(mem); ret = dma_assign_coherent_memory(dev, mem); if (ret) - dma_release_coherent_memory(mem); + _dma_release_coherent_memory(mem); return ret; } +void dma_release_coherent_memory(struct device *dev) +{ + if (dev) + _dma_release_coherent_memory(dev->dma_mem); +} + static void *__dma_alloc_from_coherent(struct device *dev, struct dma_coherent_mem *mem, ssize_t size, dma_addr_t *dma_handle) @@ -134,7 +147,7 @@ static void *__dma_alloc_from_coherent(struct device *dev, spin_lock_irqsave(&mem->spinlock, flags); - if (unlikely(size > (mem->size << PAGE_SHIFT))) + if (unlikely(size > ((dma_addr_t)mem->size << PAGE_SHIFT))) goto err; pageno = bitmap_find_free_region(mem->bitmap, mem->size, order); @@ -144,8 +157,9 @@ static void *__dma_alloc_from_coherent(struct device *dev, /* * Memory was found in the coherent area. */ - *dma_handle = dma_get_device_base(dev, mem) + (pageno << PAGE_SHIFT); - ret = mem->virt_base + (pageno << PAGE_SHIFT); + *dma_handle = dma_get_device_base(dev, mem) + + ((dma_addr_t)pageno << PAGE_SHIFT); + ret = mem->virt_base + ((dma_addr_t)pageno << PAGE_SHIFT); spin_unlock_irqrestore(&mem->spinlock, flags); memset(ret, 0, size); return ret; @@ -180,21 +194,11 @@ int dma_alloc_from_dev_coherent(struct device *dev, ssize_t size, return 1; } -void *dma_alloc_from_global_coherent(struct device *dev, ssize_t size, - dma_addr_t *dma_handle) -{ - if (!dma_coherent_default_memory) - return NULL; - - return __dma_alloc_from_coherent(dev, dma_coherent_default_memory, size, - dma_handle); -} - static int __dma_release_from_coherent(struct dma_coherent_mem *mem, int order, void *vaddr) { if (mem && vaddr >= mem->virt_base && vaddr < - (mem->virt_base + (mem->size << PAGE_SHIFT))) { + (mem->virt_base + ((dma_addr_t)mem->size << PAGE_SHIFT))) { int page = (vaddr - mem->virt_base) >> PAGE_SHIFT; unsigned long flags; @@ -225,23 +229,14 @@ int dma_release_from_dev_coherent(struct device *dev, int order, void *vaddr) return __dma_release_from_coherent(mem, order, vaddr); } -int dma_release_from_global_coherent(int order, void *vaddr) -{ - if (!dma_coherent_default_memory) - return 0; - - return __dma_release_from_coherent(dma_coherent_default_memory, order, - vaddr); -} - static int __dma_mmap_from_coherent(struct dma_coherent_mem *mem, struct vm_area_struct *vma, void *vaddr, size_t size, int *ret) { if (mem && vaddr >= mem->virt_base && vaddr + size <= - (mem->virt_base + (mem->size << PAGE_SHIFT))) { + (mem->virt_base + ((dma_addr_t)mem->size << PAGE_SHIFT))) { unsigned long off = vma->vm_pgoff; int start = (vaddr - mem->virt_base) >> PAGE_SHIFT; - int user_count = vma_pages(vma); + unsigned long user_count = vma_pages(vma); int count = PAGE_ALIGN(size) >> PAGE_SHIFT; *ret = -ENXIO; @@ -279,6 +274,28 @@ int dma_mmap_from_dev_coherent(struct device *dev, struct vm_area_struct *vma, return __dma_mmap_from_coherent(mem, vma, vaddr, size, ret); } +#ifdef CONFIG_DMA_GLOBAL_POOL +static struct dma_coherent_mem *dma_coherent_default_memory __ro_after_init; + +void *dma_alloc_from_global_coherent(struct device *dev, ssize_t size, + dma_addr_t *dma_handle) +{ + if (!dma_coherent_default_memory) + return NULL; + + return __dma_alloc_from_coherent(dev, dma_coherent_default_memory, size, + dma_handle); +} + +int dma_release_from_global_coherent(int order, void *vaddr) +{ + if (!dma_coherent_default_memory) + return 0; + + return __dma_release_from_coherent(dma_coherent_default_memory, order, + vaddr); +} + int dma_mmap_from_global_coherent(struct vm_area_struct *vma, void *vaddr, size_t size, int *ret) { @@ -289,6 +306,19 @@ int dma_mmap_from_global_coherent(struct vm_area_struct *vma, void *vaddr, vaddr, size, ret); } +int dma_init_global_coherent(phys_addr_t phys_addr, size_t size) +{ + struct dma_coherent_mem *mem; + + mem = dma_init_coherent_memory(phys_addr, phys_addr, size, true); + if (IS_ERR(mem)) + return PTR_ERR(mem); + dma_coherent_default_memory = mem; + pr_info("DMA: default coherent area is set\n"); + return 0; +} +#endif /* CONFIG_DMA_GLOBAL_POOL */ + /* * Support for reserved memory regions defined in device tree */ @@ -297,25 +327,22 @@ int dma_mmap_from_global_coherent(struct vm_area_struct *vma, void *vaddr, #include <linux/of_fdt.h> #include <linux/of_reserved_mem.h> +#ifdef CONFIG_DMA_GLOBAL_POOL static struct reserved_mem *dma_reserved_default_memory __initdata; +#endif static int rmem_dma_device_init(struct reserved_mem *rmem, struct device *dev) { - struct dma_coherent_mem *mem = rmem->priv; - int ret; - - if (!mem) { - ret = dma_init_coherent_memory(rmem->base, rmem->base, - rmem->size, &mem); - if (ret) { - pr_err("Reserved memory: failed to init DMA memory pool at %pa, size %ld MiB\n", - &rmem->base, (unsigned long)rmem->size / SZ_1M); - return ret; - } + if (!rmem->priv) { + struct dma_coherent_mem *mem; + + mem = dma_init_coherent_memory(rmem->base, rmem->base, + rmem->size, true); + if (IS_ERR(mem)) + return PTR_ERR(mem); + rmem->priv = mem; } - mem->use_dev_dma_pfn_offset = true; - rmem->priv = mem; - dma_assign_coherent_memory(dev, mem); + dma_assign_coherent_memory(dev, rmem->priv); return 0; } @@ -343,7 +370,9 @@ static int __init rmem_dma_setup(struct reserved_mem *rmem) pr_err("Reserved memory: regions without no-map are not yet supported\n"); return -EINVAL; } +#endif +#ifdef CONFIG_DMA_GLOBAL_POOL if (of_get_flat_dt_prop(node, "linux,dma-default", NULL)) { WARN(dma_reserved_default_memory, "Reserved memory: region for default DMA coherent area is redefined\n"); @@ -357,31 +386,16 @@ static int __init rmem_dma_setup(struct reserved_mem *rmem) return 0; } +#ifdef CONFIG_DMA_GLOBAL_POOL static int __init dma_init_reserved_memory(void) { - const struct reserved_mem_ops *ops; - int ret; - if (!dma_reserved_default_memory) return -ENOMEM; - - ops = dma_reserved_default_memory->ops; - - /* - * We rely on rmem_dma_device_init() does not propagate error of - * dma_assign_coherent_memory() for "NULL" device. - */ - ret = ops->device_init(dma_reserved_default_memory, NULL); - - if (!ret) { - dma_coherent_default_memory = dma_reserved_default_memory->priv; - pr_info("DMA: default coherent area is set\n"); - } - - return ret; + return dma_init_global_coherent(dma_reserved_default_memory->base, + dma_reserved_default_memory->size); } - core_initcall(dma_init_reserved_memory); +#endif /* CONFIG_DMA_GLOBAL_POOL */ RESERVEDMEM_OF_DECLARE(dma, "shared-dma-pool", rmem_dma_setup); #endif |