From 19e6e5e5392bd646c93d9e2c7b2b58c8558cb041 Mon Sep 17 00:00:00 2001 From: Rabin Vincent Date: Thu, 3 Mar 2016 15:58:00 +0100 Subject: [PATCH] ARM: 8547/1: dma-mapping: store buffer information Keep a list of allocated DMA buffers so that we can store metadata in alloc() which we later need in free(). Signed-off-by: Rabin Vincent Signed-off-by: Russell King --- arch/arm/mm/dma-mapping.c | 49 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 48 insertions(+), 1 deletion(-) diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 9f996a3d79f7..696f6ee259ee 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -42,6 +42,31 @@ #include "dma.h" #include "mm.h" +struct arm_dma_buffer { + struct list_head list; + void *virt; +}; + +static LIST_HEAD(arm_dma_bufs); +static DEFINE_SPINLOCK(arm_dma_bufs_lock); + +static struct arm_dma_buffer *arm_dma_buffer_find(void *virt) +{ + struct arm_dma_buffer *buf, *found = NULL; + unsigned long flags; + + spin_lock_irqsave(&arm_dma_bufs_lock, flags); + list_for_each_entry(buf, &arm_dma_bufs, list) { + if (buf->virt == virt) { + list_del(&buf->list); + found = buf; + break; + } + } + spin_unlock_irqrestore(&arm_dma_bufs_lock, flags); + return found; +} + /* * The DMA API is built upon the notion of "buffer ownership". A buffer * is either exclusively owned by the CPU (and therefore may be accessed @@ -620,6 +645,7 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, struct page *page = NULL; void *addr; bool want_vaddr; + struct arm_dma_buffer *buf; #ifdef CONFIG_DMA_API_DEBUG u64 limit = (mask + 1) & ~mask; @@ -633,6 +659,10 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, if (!mask) return NULL; + buf = kzalloc(sizeof(*buf), gfp); + if (!buf) + return NULL; + if (mask < 0xffffffffULL) gfp |= GFP_DMA; @@ -662,8 +692,18 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, addr = __alloc_remap_buffer(dev, size, gfp, prot, &page, caller, want_vaddr); - if (page) + if (page) { + unsigned long flags; + *handle = pfn_to_dma(dev, page_to_pfn(page)); + buf->virt = want_vaddr ? addr : page; + + spin_lock_irqsave(&arm_dma_bufs_lock, flags); + list_add(&buf->list, &arm_dma_bufs); + spin_unlock_irqrestore(&arm_dma_bufs_lock, flags); + } else { + kfree(buf); + } return want_vaddr ? addr : page; } @@ -742,6 +782,11 @@ static void __arm_dma_free(struct device *dev, size_t size, void *cpu_addr, { struct page *page = pfn_to_page(dma_to_pfn(dev, handle)); bool want_vaddr = !dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs); + struct arm_dma_buffer *buf; + + buf = arm_dma_buffer_find(cpu_addr); + if (WARN(!buf, "Freeing invalid buffer %p\n", cpu_addr)) + return; size = PAGE_ALIGN(size); @@ -760,6 +805,8 @@ static void __arm_dma_free(struct device *dev, size_t size, void *cpu_addr, WARN_ON(irqs_disabled()); __free_from_contiguous(dev, page, cpu_addr, size, want_vaddr); } + + kfree(buf); } void arm_dma_free(struct device *dev, size_t size, void *cpu_addr, -- 2.20.1