diff options
Diffstat (limited to 'drivers/base/dma-coherent.c')
| -rw-r--r-- | drivers/base/dma-coherent.c | 151 |
1 files changed, 129 insertions, 22 deletions
diff --git a/drivers/base/dma-coherent.c b/drivers/base/dma-coherent.c index 7d6e84a5142..55b83983a9c 100644 --- a/drivers/base/dma-coherent.c +++ b/drivers/base/dma-coherent.c @@ -14,11 +14,14 @@ struct dma_coherent_mem { int size; int flags; unsigned long *bitmap; + spinlock_t spinlock; }; -int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr, - dma_addr_t device_addr, size_t size, int flags) +static int dma_init_coherent_memory(phys_addr_t phys_addr, dma_addr_t device_addr, + size_t size, int flags, + struct dma_coherent_mem **mem) { + struct dma_coherent_mem *dma_mem = NULL; void __iomem *mem_base = NULL; int pages = size >> PAGE_SHIFT; int bitmap_size = BITS_TO_LONGS(pages) * sizeof(long); @@ -27,40 +30,77 @@ int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr, goto out; if (!size) goto out; - if (dev->dma_mem) - goto out; - - /* FIXME: this routine just ignores DMA_MEMORY_INCLUDES_CHILDREN */ mem_base = ioremap(phys_addr, size); if (!mem_base) goto out; - dev->dma_mem = kzalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL); - if (!dev->dma_mem) + dma_mem = kzalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL); + if (!dma_mem) goto out; - dev->dma_mem->bitmap = kzalloc(bitmap_size, GFP_KERNEL); - if (!dev->dma_mem->bitmap) - goto free1_out; + dma_mem->bitmap = kzalloc(bitmap_size, GFP_KERNEL); + if (!dma_mem->bitmap) + goto out; + + 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->flags = flags; + spin_lock_init(&dma_mem->spinlock); - dev->dma_mem->virt_base = mem_base; - dev->dma_mem->device_base = device_addr; - dev->dma_mem->pfn_base = PFN_DOWN(phys_addr); - dev->dma_mem->size = pages; - dev->dma_mem->flags = flags; + *mem = dma_mem; if (flags & DMA_MEMORY_MAP) return DMA_MEMORY_MAP; return DMA_MEMORY_IO; - free1_out: - kfree(dev->dma_mem); - out: +out: + kfree(dma_mem); if (mem_base) iounmap(mem_base); return 0; } + +static void dma_release_coherent_memory(struct dma_coherent_mem *mem) +{ + if (!mem) + return; + iounmap(mem->virt_base); + kfree(mem->bitmap); + kfree(mem); +} + +static int dma_assign_coherent_memory(struct device *dev, + struct dma_coherent_mem *mem) +{ + if (dev->dma_mem) + return -EBUSY; + + dev->dma_mem = mem; + /* FIXME: this routine just ignores DMA_MEMORY_INCLUDES_CHILDREN */ + + return 0; +} + +int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr, + dma_addr_t device_addr, size_t size, int flags) +{ + struct dma_coherent_mem *mem; + int ret; + + ret = dma_init_coherent_memory(phys_addr, device_addr, size, flags, + &mem); + if (ret == 0) + return 0; + + if (dma_assign_coherent_memory(dev, mem) == 0) + return ret; + + dma_release_coherent_memory(mem); + return 0; +} EXPORT_SYMBOL(dma_declare_coherent_memory); void dma_release_declared_memory(struct device *dev) @@ -69,10 +109,8 @@ void dma_release_declared_memory(struct device *dev) if (!mem) return; + dma_release_coherent_memory(mem); dev->dma_mem = NULL; - iounmap(mem->virt_base); - kfree(mem->bitmap); - kfree(mem); } EXPORT_SYMBOL(dma_release_declared_memory); @@ -80,6 +118,7 @@ void *dma_mark_declared_memory_occupied(struct device *dev, dma_addr_t device_addr, size_t size) { struct dma_coherent_mem *mem = dev->dma_mem; + unsigned long flags; int pos, err; size += device_addr & ~PAGE_MASK; @@ -87,8 +126,11 @@ void *dma_mark_declared_memory_occupied(struct device *dev, if (!mem) return ERR_PTR(-EINVAL); + spin_lock_irqsave(&mem->spinlock, flags); pos = (device_addr - mem->device_base) >> PAGE_SHIFT; err = bitmap_allocate_region(mem->bitmap, pos, get_order(size)); + spin_unlock_irqrestore(&mem->spinlock, flags); + if (err != 0) return ERR_PTR(err); return mem->virt_base + (pos << PAGE_SHIFT); @@ -115,6 +157,7 @@ int dma_alloc_from_coherent(struct device *dev, ssize_t size, { struct dma_coherent_mem *mem; int order = get_order(size); + unsigned long flags; int pageno; if (!dev) @@ -124,6 +167,7 @@ int dma_alloc_from_coherent(struct device *dev, ssize_t size, return 0; *ret = NULL; + spin_lock_irqsave(&mem->spinlock, flags); if (unlikely(size > (mem->size << PAGE_SHIFT))) goto err; @@ -138,10 +182,12 @@ int dma_alloc_from_coherent(struct device *dev, ssize_t size, *dma_handle = mem->device_base + (pageno << PAGE_SHIFT); *ret = mem->virt_base + (pageno << PAGE_SHIFT); memset(*ret, 0, size); + spin_unlock_irqrestore(&mem->spinlock, flags); return 1; err: + spin_unlock_irqrestore(&mem->spinlock, flags); /* * In the case where the allocation can not be satisfied from the * per-device area, try to fall back to generic memory if the @@ -171,8 +217,11 @@ int dma_release_from_coherent(struct device *dev, int order, void *vaddr) if (mem && vaddr >= mem->virt_base && vaddr < (mem->virt_base + (mem->size << PAGE_SHIFT))) { int page = (vaddr - mem->virt_base) >> PAGE_SHIFT; + unsigned long flags; + spin_lock_irqsave(&mem->spinlock, flags); bitmap_release_region(mem->bitmap, page, order); + spin_unlock_irqrestore(&mem->spinlock, flags); return 1; } return 0; @@ -218,3 +267,61 @@ int dma_mmap_from_coherent(struct device *dev, struct vm_area_struct *vma, return 0; } EXPORT_SYMBOL(dma_mmap_from_coherent); + +/* + * Support for reserved memory regions defined in device tree + */ +#ifdef CONFIG_OF_RESERVED_MEM +#include <linux/of.h> +#include <linux/of_fdt.h> +#include <linux/of_reserved_mem.h> + +static int rmem_dma_device_init(struct reserved_mem *rmem, struct device *dev) +{ + struct dma_coherent_mem *mem = rmem->priv; + + if (!mem && + dma_init_coherent_memory(rmem->base, rmem->base, rmem->size, + DMA_MEMORY_MAP | DMA_MEMORY_EXCLUSIVE, + &mem) != DMA_MEMORY_MAP) { + 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 -ENODEV; + } + rmem->priv = mem; + dma_assign_coherent_memory(dev, mem); + return 0; +} + +static void rmem_dma_device_release(struct reserved_mem *rmem, + struct device *dev) +{ + dev->dma_mem = NULL; +} + +static const struct reserved_mem_ops rmem_dma_ops = { + .device_init = rmem_dma_device_init, + .device_release = rmem_dma_device_release, +}; + +static int __init rmem_dma_setup(struct reserved_mem *rmem) +{ + unsigned long node = rmem->fdt_node; + + if (of_get_flat_dt_prop(node, "reusable", NULL)) + return -EINVAL; + +#ifdef CONFIG_ARM + if (!of_get_flat_dt_prop(node, "no-map", NULL)) { + pr_err("Reserved memory: regions without no-map are not yet supported\n"); + return -EINVAL; + } +#endif + + rmem->ops = &rmem_dma_ops; + pr_info("Reserved memory: created DMA memory pool at %pa, size %ld MiB\n", + &rmem->base, (unsigned long)rmem->size / SZ_1M); + return 0; +} +RESERVEDMEM_OF_DECLARE(dma, "shared-dma-pool", rmem_dma_setup); +#endif |