From 43fc509c3efb5c973991ee24c449ab2a0d71dd1e Mon Sep 17 00:00:00 2001 From: Vladimir Murzin Date: Thu, 20 Jul 2017 11:19:58 +0100 Subject: dma-coherent: introduce interface for default DMA pool Christoph noticed [1] that default DMA pool in current form overload the DMA coherent infrastructure. In reply, Robin suggested [2] to split the per-device vs. global pool interfaces, so allocation/release from default DMA pool is driven by dma ops implementation. This patch implements Robin's idea and provide interface to allocate/release/mmap the default (aka global) DMA pool. To make it clear that existing *_from_coherent routines work on per-device pool rename them to *_from_dev_coherent. [1] https://lkml.org/lkml/2017/7/7/370 [2] https://lkml.org/lkml/2017/7/7/431 Cc: Vineet Gupta Cc: Russell King Cc: Catalin Marinas Cc: Will Deacon Cc: Ralf Baechle Suggested-by: Robin Murphy Tested-by: Andras Szemzo Reviewed-by: Robin Murphy Signed-off-by: Vladimir Murzin Signed-off-by: Christoph Hellwig --- drivers/base/dma-coherent.c | 164 ++++++++++++++++++++++++++++---------------- drivers/base/dma-mapping.c | 2 +- 2 files changed, 107 insertions(+), 59 deletions(-) (limited to 'drivers') diff --git a/drivers/base/dma-coherent.c b/drivers/base/dma-coherent.c index 2ae24c2..1c152ae 100644 --- a/drivers/base/dma-coherent.c +++ b/drivers/base/dma-coherent.c @@ -25,7 +25,7 @@ static inline struct dma_coherent_mem *dev_get_coherent_memory(struct device *de { if (dev && dev->dma_mem) return dev->dma_mem; - return dma_coherent_default_memory; + return NULL; } static inline dma_addr_t dma_get_device_base(struct device *dev, @@ -165,34 +165,15 @@ void *dma_mark_declared_memory_occupied(struct device *dev, } EXPORT_SYMBOL(dma_mark_declared_memory_occupied); -/** - * dma_alloc_from_coherent() - try to allocate memory from the per-device coherent area - * - * @dev: device from which we allocate memory - * @size: size of requested memory area - * @dma_handle: This will be filled with the correct dma handle - * @ret: This pointer will be filled with the virtual address - * to allocated area. - * - * This function should be only called from per-arch dma_alloc_coherent() - * to support allocation from per-device coherent memory pools. - * - * Returns 0 if dma_alloc_coherent should continue with allocating from - * generic memory areas, or !0 if dma_alloc_coherent should return @ret. - */ -int dma_alloc_from_coherent(struct device *dev, ssize_t size, - dma_addr_t *dma_handle, void **ret) +static void *__dma_alloc_from_coherent(struct dma_coherent_mem *mem, + ssize_t size, dma_addr_t *dma_handle) { - struct dma_coherent_mem *mem = dev_get_coherent_memory(dev); int order = get_order(size); unsigned long flags; int pageno; int dma_memory_map; + void *ret; - if (!mem) - return 0; - - *ret = NULL; spin_lock_irqsave(&mem->spinlock, flags); if (unlikely(size > (mem->size << PAGE_SHIFT))) @@ -203,21 +184,50 @@ int dma_alloc_from_coherent(struct device *dev, ssize_t size, goto err; /* - * Memory was found in the per-device area. + * 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 = mem->device_base + (pageno << PAGE_SHIFT); + ret = mem->virt_base + (pageno << PAGE_SHIFT); dma_memory_map = (mem->flags & DMA_MEMORY_MAP); spin_unlock_irqrestore(&mem->spinlock, flags); if (dma_memory_map) - memset(*ret, 0, size); + memset(ret, 0, size); else - memset_io(*ret, 0, size); + memset_io(ret, 0, size); - return 1; + return ret; err: spin_unlock_irqrestore(&mem->spinlock, flags); + return NULL; +} + +/** + * dma_alloc_from_dev_coherent() - allocate memory from device coherent pool + * @dev: device from which we allocate memory + * @size: size of requested memory area + * @dma_handle: This will be filled with the correct dma handle + * @ret: This pointer will be filled with the virtual address + * to allocated area. + * + * This function should be only called from per-arch dma_alloc_coherent() + * to support allocation from per-device coherent memory pools. + * + * Returns 0 if dma_alloc_coherent should continue with allocating from + * generic memory areas, or !0 if dma_alloc_coherent should return @ret. + */ +int dma_alloc_from_dev_coherent(struct device *dev, ssize_t size, + dma_addr_t *dma_handle, void **ret) +{ + struct dma_coherent_mem *mem = dev_get_coherent_memory(dev); + + if (!mem) + return 0; + + *ret = __dma_alloc_from_coherent(mem, size, dma_handle); + if (*ret) + return 1; + /* * In the case where the allocation can not be satisfied from the * per-device area, try to fall back to generic memory if the @@ -225,25 +235,20 @@ err: */ return mem->flags & DMA_MEMORY_EXCLUSIVE; } -EXPORT_SYMBOL(dma_alloc_from_coherent); +EXPORT_SYMBOL(dma_alloc_from_dev_coherent); -/** - * dma_release_from_coherent() - try to free the memory allocated from per-device coherent memory pool - * @dev: device from which the memory was allocated - * @order: the order of pages allocated - * @vaddr: virtual address of allocated pages - * - * This checks whether the memory was allocated from the per-device - * coherent memory pool and if so, releases that memory. - * - * Returns 1 if we correctly released the memory, or 0 if - * dma_release_coherent() should proceed with releasing memory from - * generic pools. - */ -int dma_release_from_coherent(struct device *dev, int order, void *vaddr) +void *dma_alloc_from_global_coherent(ssize_t size, dma_addr_t *dma_handle) { - struct dma_coherent_mem *mem = dev_get_coherent_memory(dev); + if (!dma_coherent_default_memory) + return NULL; + + return __dma_alloc_from_coherent(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))) { int page = (vaddr - mem->virt_base) >> PAGE_SHIFT; @@ -256,28 +261,39 @@ int dma_release_from_coherent(struct device *dev, int order, void *vaddr) } return 0; } -EXPORT_SYMBOL(dma_release_from_coherent); /** - * dma_mmap_from_coherent() - try to mmap the memory allocated from - * per-device coherent memory pool to userspace + * dma_release_from_dev_coherent() - free memory to device coherent memory pool * @dev: device from which the memory was allocated - * @vma: vm_area for the userspace memory - * @vaddr: cpu address returned by dma_alloc_from_coherent - * @size: size of the memory buffer allocated by dma_alloc_from_coherent - * @ret: result from remap_pfn_range() + * @order: the order of pages allocated + * @vaddr: virtual address of allocated pages * * This checks whether the memory was allocated from the per-device - * coherent memory pool and if so, maps that memory to the provided vma. + * coherent memory pool and if so, releases that memory. * - * Returns 1 if we correctly mapped the memory, or 0 if the caller should - * proceed with mapping memory from generic pools. + * Returns 1 if we correctly released the memory, or 0 if the caller should + * proceed with releasing memory from generic pools. */ -int dma_mmap_from_coherent(struct device *dev, struct vm_area_struct *vma, - void *vaddr, size_t size, int *ret) +int dma_release_from_dev_coherent(struct device *dev, int order, void *vaddr) { struct dma_coherent_mem *mem = dev_get_coherent_memory(dev); + return __dma_release_from_coherent(mem, order, vaddr); +} +EXPORT_SYMBOL(dma_release_from_dev_coherent); + +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))) { unsigned long off = vma->vm_pgoff; @@ -296,7 +312,39 @@ int dma_mmap_from_coherent(struct device *dev, struct vm_area_struct *vma, } return 0; } -EXPORT_SYMBOL(dma_mmap_from_coherent); + +/** + * dma_mmap_from_dev_coherent() - mmap memory from the device coherent pool + * @dev: device from which the memory was allocated + * @vma: vm_area for the userspace memory + * @vaddr: cpu address returned by dma_alloc_from_dev_coherent + * @size: size of the memory buffer allocated + * @ret: result from remap_pfn_range() + * + * This checks whether the memory was allocated from the per-device + * coherent memory pool and if so, maps that memory to the provided vma. + * + * Returns 1 if we correctly mapped the memory, or 0 if the caller should + * proceed with mapping memory from generic pools. + */ +int dma_mmap_from_dev_coherent(struct device *dev, struct vm_area_struct *vma, + void *vaddr, size_t size, int *ret) +{ + struct dma_coherent_mem *mem = dev_get_coherent_memory(dev); + + return __dma_mmap_from_coherent(mem, vma, vaddr, size, ret); +} +EXPORT_SYMBOL(dma_mmap_from_dev_coherent); + +int dma_mmap_from_global_coherent(struct vm_area_struct *vma, void *vaddr, + size_t size, int *ret) +{ + if (!dma_coherent_default_memory) + return 0; + + return __dma_mmap_from_coherent(dma_coherent_default_memory, vma, + vaddr, size, ret); +} /* * Support for reserved memory regions defined in device tree diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c index 5096755..b555ff9 100644 --- a/drivers/base/dma-mapping.c +++ b/drivers/base/dma-mapping.c @@ -235,7 +235,7 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma, vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); - if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret)) + if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret)) return ret; if (off < count && user_count <= (count - off)) { -- cgit v1.1