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Message-Id: <1407800431-21566-4-git-send-email-lauraa@codeaurora.org>
Date: Mon, 11 Aug 2014 16:40:29 -0700
From: Laura Abbott <lauraa@...eaurora.org>
To: Will Deacon <will.deacon@....com>,
Catalin Marinas <catalin.marinas@....com>,
Russell King <linux@....linux.org.uk>,
Andrew Morton <akpm@...ux-foundation.org>
Cc: Laura Abbott <lauraa@...eaurora.org>,
David Riley <davidriley@...omium.org>,
linux-arm-kernel@...ts.infradead.org,
Ritesh Harjain <ritesh.harjani@...il.com>, linux-mm@...ck.org,
linux-kernel@...r.kernel.org,
Thierry Reding <thierry.reding@...il.com>,
Arnd Bergmann <arnd@...db.de>
Subject: [PATCHv7 3/5] common: dma-mapping: Introduce common remapping functions
For architectures without coherent DMA, memory for DMA may
need to be remapped with coherent attributes. Factor out
the the remapping code from arm and put it in a
common location to reduce code duplication.
As part of this, the arm APIs are now migrated away from
ioremap_page_range to the common APIs which use map_vm_area for remapping.
This should be an equivalent change and using map_vm_area is more
correct as ioremap_page_range is intended to bring in io addresses
into the cpu space and not regular kernel managed memory.
Reviewed-by: Catalin Marinas <catalin.marinas@....com>
Signed-off-by: Laura Abbott <lauraa@...eaurora.org>
---
arch/arm/mm/dma-mapping.c | 57 +++++---------------------
drivers/base/dma-mapping.c | 68 ++++++++++++++++++++++++++++++++
include/asm-generic/dma-mapping-common.h | 9 +++++
3 files changed, 86 insertions(+), 48 deletions(-)
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 4c88935..f5190ac 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -297,37 +297,19 @@ static void *
__dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t prot,
const void *caller)
{
- struct vm_struct *area;
- unsigned long addr;
-
/*
* DMA allocation can be mapped to user space, so lets
* set VM_USERMAP flags too.
*/
- area = get_vm_area_caller(size, VM_ARM_DMA_CONSISTENT | VM_USERMAP,
- caller);
- if (!area)
- return NULL;
- addr = (unsigned long)area->addr;
- area->phys_addr = __pfn_to_phys(page_to_pfn(page));
-
- if (ioremap_page_range(addr, addr + size, area->phys_addr, prot)) {
- vunmap((void *)addr);
- return NULL;
- }
- return (void *)addr;
+ return dma_common_contiguous_remap(page, size,
+ VM_ARM_DMA_CONSISTENT | VM_USERMAP,
+ prot, caller);
}
static void __dma_free_remap(void *cpu_addr, size_t size)
{
- unsigned int flags = VM_ARM_DMA_CONSISTENT | VM_USERMAP;
- struct vm_struct *area = find_vm_area(cpu_addr);
- if (!area || (area->flags & flags) != flags) {
- WARN(1, "trying to free invalid coherent area: %p\n", cpu_addr);
- return;
- }
- unmap_kernel_range((unsigned long)cpu_addr, size);
- vunmap(cpu_addr);
+ dma_common_free_remap(cpu_addr, size,
+ VM_ARM_DMA_CONSISTENT | VM_USERMAP);
}
#define DEFAULT_DMA_COHERENT_POOL_SIZE SZ_256K
@@ -1261,29 +1243,8 @@ static void *
__iommu_alloc_remap(struct page **pages, size_t size, gfp_t gfp, pgprot_t prot,
const void *caller)
{
- unsigned int i, nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
- struct vm_struct *area;
- unsigned long p;
-
- area = get_vm_area_caller(size, VM_ARM_DMA_CONSISTENT | VM_USERMAP,
- caller);
- if (!area)
- return NULL;
-
- area->pages = pages;
- area->nr_pages = nr_pages;
- p = (unsigned long)area->addr;
-
- for (i = 0; i < nr_pages; i++) {
- phys_addr_t phys = __pfn_to_phys(page_to_pfn(pages[i]));
- if (ioremap_page_range(p, p + PAGE_SIZE, phys, prot))
- goto err;
- p += PAGE_SIZE;
- }
- return area->addr;
-err:
- unmap_kernel_range((unsigned long)area->addr, size);
- vunmap(area->addr);
+ return dma_common_pages_remap(pages, size,
+ VM_ARM_DMA_CONSISTENT | VM_USERMAP, prot, caller);
return NULL;
}
@@ -1491,8 +1452,8 @@ void arm_iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr,
}
if (!dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs)) {
- unmap_kernel_range((unsigned long)cpu_addr, size);
- vunmap(cpu_addr);
+ dma_common_free_remap(cpu_addr, size,
+ VM_ARM_DMA_CONSISTENT | VM_USERMAP);
}
__iommu_remove_mapping(dev, handle, size);
diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
index 6cd08e1..1bc46df 100644
--- a/drivers/base/dma-mapping.c
+++ b/drivers/base/dma-mapping.c
@@ -10,6 +10,8 @@
#include <linux/dma-mapping.h>
#include <linux/export.h>
#include <linux/gfp.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
#include <asm-generic/dma-coherent.h>
/*
@@ -267,3 +269,69 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
return ret;
}
EXPORT_SYMBOL(dma_common_mmap);
+
+/*
+ * remaps an allocated contiguous region into another vm_area.
+ * Cannot be used in non-sleeping contexts
+ */
+
+void *dma_common_contiguous_remap(struct page *page, size_t size,
+ unsigned long vm_flags,
+ pgprot_t prot, const void *caller)
+{
+ int i;
+ struct page **pages;
+ void *ptr;
+ unsigned long pfn;
+
+ pages = kmalloc(sizeof(struct page *) << get_order(size), GFP_KERNEL);
+ if (!pages)
+ return NULL;
+
+ for (i = 0, pfn = page_to_pfn(page); i < (size >> PAGE_SHIFT); i++)
+ pages[i] = pfn_to_page(pfn + i);
+
+ ptr = dma_common_pages_remap(pages, size, vm_flags, prot, caller);
+
+ kfree(pages);
+
+ return ptr;
+}
+
+/*
+ * remaps an array of PAGE_SIZE pages into another vm_area
+ * Cannot be used in non-sleeping contexts
+ */
+void *dma_common_pages_remap(struct page **pages, size_t size,
+ unsigned long vm_flags, pgprot_t prot,
+ const void *caller)
+{
+ struct vm_struct *area;
+
+ area = get_vm_area_caller(size, vm_flags, caller);
+ if (!area)
+ return NULL;
+
+ if (map_vm_area(area, prot, pages)) {
+ vunmap(area->addr);
+ return NULL;
+ }
+
+ return area->addr;
+}
+
+/*
+ * unmaps a range previously mapped by dma_common_*_remap
+ */
+void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags)
+{
+ struct vm_struct *area = find_vm_area(cpu_addr);
+
+ if (!area || (area->flags & vm_flags) != vm_flags) {
+ WARN(1, "trying to free invalid coherent area: %p\n", cpu_addr);
+ return;
+ }
+
+ unmap_kernel_range((unsigned long)cpu_addr, size);
+ vunmap(cpu_addr);
+}
diff --git a/include/asm-generic/dma-mapping-common.h b/include/asm-generic/dma-mapping-common.h
index de8bf89..a9fd248 100644
--- a/include/asm-generic/dma-mapping-common.h
+++ b/include/asm-generic/dma-mapping-common.h
@@ -179,6 +179,15 @@ dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
extern int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t dma_addr, size_t size);
+void *dma_common_contiguous_remap(struct page *page, size_t size,
+ unsigned long vm_flags,
+ pgprot_t prot, const void *caller);
+
+void *dma_common_pages_remap(struct page **pages, size_t size,
+ unsigned long vm_flags, pgprot_t prot,
+ const void *caller);
+void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags);
+
/**
* dma_mmap_attrs - map a coherent DMA allocation into user space
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
hosted by The Linux Foundation
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