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Commit 19e6e5e5 authored by Rabin Vincent's avatar Rabin Vincent Committed by Russell King
Browse files

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: default avatarRabin Vincent <rabin.vincent@axis.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent f57deb0b

arch/arm/mm/dma-mapping.c

+48 −1
Original line number Diff line number Diff line
@@ -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,