diff options
Diffstat (limited to 'drivers/base/dma-coherent.c')
| -rw-r--r-- | drivers/base/dma-coherent.c | 74 |
1 files changed, 65 insertions, 9 deletions
diff --git a/drivers/base/dma-coherent.c b/drivers/base/dma-coherent.c index 640a7e63c453..2ae24c28e70c 100644 --- a/drivers/base/dma-coherent.c +++ b/drivers/base/dma-coherent.c @@ -16,8 +16,27 @@ struct dma_coherent_mem { int flags; unsigned long *bitmap; spinlock_t spinlock; + 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) + return dev->dma_mem; + return dma_coherent_default_memory; +} + +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; +} + static bool dma_init_coherent_memory( phys_addr_t phys_addr, dma_addr_t device_addr, size_t size, int flags, struct dma_coherent_mem **mem) @@ -83,6 +102,9 @@ static void dma_release_coherent_memory(struct dma_coherent_mem *mem) static int dma_assign_coherent_memory(struct device *dev, struct dma_coherent_mem *mem) { + if (!dev) + return -ENODEV; + if (dev->dma_mem) return -EBUSY; @@ -133,7 +155,7 @@ void *dma_mark_declared_memory_occupied(struct device *dev, return ERR_PTR(-EINVAL); spin_lock_irqsave(&mem->spinlock, flags); - pos = (device_addr - mem->device_base) >> PAGE_SHIFT; + pos = PFN_DOWN(device_addr - dma_get_device_base(dev, mem)); err = bitmap_allocate_region(mem->bitmap, pos, get_order(size)); spin_unlock_irqrestore(&mem->spinlock, flags); @@ -161,15 +183,12 @@ EXPORT_SYMBOL(dma_mark_declared_memory_occupied); int dma_alloc_from_coherent(struct device *dev, ssize_t size, dma_addr_t *dma_handle, void **ret) { - struct dma_coherent_mem *mem; + struct dma_coherent_mem *mem = dev_get_coherent_memory(dev); int order = get_order(size); unsigned long flags; int pageno; int dma_memory_map; - if (!dev) - return 0; - mem = dev->dma_mem; if (!mem) return 0; @@ -186,7 +205,7 @@ int dma_alloc_from_coherent(struct device *dev, ssize_t size, /* * Memory was found in the per-device area. */ - *dma_handle = mem->device_base + (pageno << PAGE_SHIFT); + *dma_handle = dma_get_device_base(dev, mem) + (pageno << PAGE_SHIFT); *ret = mem->virt_base + (pageno << PAGE_SHIFT); dma_memory_map = (mem->flags & DMA_MEMORY_MAP); spin_unlock_irqrestore(&mem->spinlock, flags); @@ -223,7 +242,7 @@ EXPORT_SYMBOL(dma_alloc_from_coherent); */ int dma_release_from_coherent(struct device *dev, int order, void *vaddr) { - struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL; + struct dma_coherent_mem *mem = dev_get_coherent_memory(dev); if (mem && vaddr >= mem->virt_base && vaddr < (mem->virt_base + (mem->size << PAGE_SHIFT))) { @@ -257,7 +276,7 @@ EXPORT_SYMBOL(dma_release_from_coherent); int dma_mmap_from_coherent(struct device *dev, struct vm_area_struct *vma, void *vaddr, size_t size, int *ret) { - struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL; + struct dma_coherent_mem *mem = dev_get_coherent_memory(dev); if (mem && vaddr >= mem->virt_base && vaddr + size <= (mem->virt_base + (mem->size << PAGE_SHIFT))) { @@ -287,6 +306,8 @@ EXPORT_SYMBOL(dma_mmap_from_coherent); #include <linux/of_fdt.h> #include <linux/of_reserved_mem.h> +static struct reserved_mem *dma_reserved_default_memory __initdata; + static int rmem_dma_device_init(struct reserved_mem *rmem, struct device *dev) { struct dma_coherent_mem *mem = rmem->priv; @@ -299,6 +320,7 @@ static int rmem_dma_device_init(struct reserved_mem *rmem, struct device *dev) &rmem->base, (unsigned long)rmem->size / SZ_1M); return -ENODEV; } + mem->use_dev_dma_pfn_offset = true; rmem->priv = mem; dma_assign_coherent_memory(dev, mem); return 0; @@ -307,7 +329,8 @@ static int rmem_dma_device_init(struct reserved_mem *rmem, struct device *dev) static void rmem_dma_device_release(struct reserved_mem *rmem, struct device *dev) { - dev->dma_mem = NULL; + if (dev) + dev->dma_mem = NULL; } static const struct reserved_mem_ops rmem_dma_ops = { @@ -327,6 +350,12 @@ 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; } + + 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"); + dma_reserved_default_memory = rmem; + } #endif rmem->ops = &rmem_dma_ops; @@ -334,5 +363,32 @@ static int __init rmem_dma_setup(struct reserved_mem *rmem) &rmem->base, (unsigned long)rmem->size / SZ_1M); return 0; } + +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; +} + +core_initcall(dma_init_reserved_memory); + RESERVEDMEM_OF_DECLARE(dma, "shared-dma-pool", rmem_dma_setup); #endif |