![Krzysztof Kozlowski](/assets/img/avatar_default.png)
The dma-mapping core and the implementations do not change the DMA attributes passed by pointer. Thus the pointer can point to const data. However the attributes do not have to be a bitfield. Instead unsigned long will do fine: 1. This is just simpler. Both in terms of reading the code and setting attributes. Instead of initializing local attributes on the stack and passing pointer to it to dma_set_attr(), just set the bits. 2. It brings safeness and checking for const correctness because the attributes are passed by value. Semantic patches for this change (at least most of them): virtual patch virtual context @r@ identifier f, attrs; @@ f(..., - struct dma_attrs *attrs + unsigned long attrs , ...) { ... } @@ identifier r.f; @@ f(..., - NULL + 0 ) and // Options: --all-includes virtual patch virtual context @r@ identifier f, attrs; type t; @@ t f(..., struct dma_attrs *attrs); @@ identifier r.f; @@ f(..., - NULL + 0 ) Link: http://lkml.kernel.org/r/1468399300-5399-2-git-send-email-k.kozlowski@samsung.com Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Acked-by: Vineet Gupta <vgupta@synopsys.com> Acked-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Hans-Christian Noren Egtvedt <egtvedt@samfundet.no> Acked-by: Mark Salter <msalter@redhat.com> [c6x] Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> [cris] Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> [drm] Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com> Acked-by: Joerg Roedel <jroedel@suse.de> [iommu] Acked-by: Fabien Dessenne <fabien.dessenne@st.com> [bdisp] Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com> [vb2-core] Acked-by: David Vrabel <david.vrabel@citrix.com> [xen] Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> [xen swiotlb] Acked-by: Joerg Roedel <jroedel@suse.de> [iommu] Acked-by: Richard Kuo <rkuo@codeaurora.org> [hexagon] Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k] Acked-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> [s390] Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org> Acked-by: Hans-Christian Noren Egtvedt <egtvedt@samfundet.no> [avr32] Acked-by: Vineet Gupta <vgupta@synopsys.com> [arc] Acked-by: Robin Murphy <robin.murphy@arm.com> [arm64 and dma-iommu] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
144 lines
3.5 KiB
C
144 lines
3.5 KiB
C
/*
|
|
* Copyright (C) 2011 Texas Instruments Incorporated
|
|
* Author: Mark Salter <msalter@redhat.com>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*/
|
|
#include <linux/module.h>
|
|
#include <linux/dma-mapping.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/mm_types.h>
|
|
#include <linux/scatterlist.h>
|
|
|
|
#include <asm/cacheflush.h>
|
|
|
|
static void c6x_dma_sync(dma_addr_t handle, size_t size,
|
|
enum dma_data_direction dir)
|
|
{
|
|
unsigned long paddr = handle;
|
|
|
|
BUG_ON(!valid_dma_direction(dir));
|
|
|
|
switch (dir) {
|
|
case DMA_FROM_DEVICE:
|
|
L2_cache_block_invalidate(paddr, paddr + size);
|
|
break;
|
|
case DMA_TO_DEVICE:
|
|
L2_cache_block_writeback(paddr, paddr + size);
|
|
break;
|
|
case DMA_BIDIRECTIONAL:
|
|
L2_cache_block_writeback_invalidate(paddr, paddr + size);
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
|
|
static dma_addr_t c6x_dma_map_page(struct device *dev, struct page *page,
|
|
unsigned long offset, size_t size, enum dma_data_direction dir,
|
|
unsigned long attrs)
|
|
{
|
|
dma_addr_t handle = virt_to_phys(page_address(page) + offset);
|
|
|
|
c6x_dma_sync(handle, size, dir);
|
|
return handle;
|
|
}
|
|
|
|
static void c6x_dma_unmap_page(struct device *dev, dma_addr_t handle,
|
|
size_t size, enum dma_data_direction dir, unsigned long attrs)
|
|
{
|
|
c6x_dma_sync(handle, size, dir);
|
|
}
|
|
|
|
static int c6x_dma_map_sg(struct device *dev, struct scatterlist *sglist,
|
|
int nents, enum dma_data_direction dir, unsigned long attrs)
|
|
{
|
|
struct scatterlist *sg;
|
|
int i;
|
|
|
|
for_each_sg(sglist, sg, nents, i) {
|
|
sg->dma_address = sg_phys(sg);
|
|
c6x_dma_sync(sg->dma_address, sg->length, dir);
|
|
}
|
|
|
|
return nents;
|
|
}
|
|
|
|
static void c6x_dma_unmap_sg(struct device *dev, struct scatterlist *sglist,
|
|
int nents, enum dma_data_direction dir, unsigned long attrs)
|
|
{
|
|
struct scatterlist *sg;
|
|
int i;
|
|
|
|
for_each_sg(sglist, sg, nents, i)
|
|
c6x_dma_sync(sg_dma_address(sg), sg->length, dir);
|
|
|
|
}
|
|
|
|
static void c6x_dma_sync_single_for_cpu(struct device *dev, dma_addr_t handle,
|
|
size_t size, enum dma_data_direction dir)
|
|
{
|
|
c6x_dma_sync(handle, size, dir);
|
|
|
|
}
|
|
|
|
static void c6x_dma_sync_single_for_device(struct device *dev,
|
|
dma_addr_t handle, size_t size, enum dma_data_direction dir)
|
|
{
|
|
c6x_dma_sync(handle, size, dir);
|
|
|
|
}
|
|
|
|
static void c6x_dma_sync_sg_for_cpu(struct device *dev,
|
|
struct scatterlist *sglist, int nents,
|
|
enum dma_data_direction dir)
|
|
{
|
|
struct scatterlist *sg;
|
|
int i;
|
|
|
|
for_each_sg(sglist, sg, nents, i)
|
|
c6x_dma_sync_single_for_cpu(dev, sg_dma_address(sg),
|
|
sg->length, dir);
|
|
|
|
}
|
|
|
|
static void c6x_dma_sync_sg_for_device(struct device *dev,
|
|
struct scatterlist *sglist, int nents,
|
|
enum dma_data_direction dir)
|
|
{
|
|
struct scatterlist *sg;
|
|
int i;
|
|
|
|
for_each_sg(sglist, sg, nents, i)
|
|
c6x_dma_sync_single_for_device(dev, sg_dma_address(sg),
|
|
sg->length, dir);
|
|
|
|
}
|
|
|
|
struct dma_map_ops c6x_dma_ops = {
|
|
.alloc = c6x_dma_alloc,
|
|
.free = c6x_dma_free,
|
|
.map_page = c6x_dma_map_page,
|
|
.unmap_page = c6x_dma_unmap_page,
|
|
.map_sg = c6x_dma_map_sg,
|
|
.unmap_sg = c6x_dma_unmap_sg,
|
|
.sync_single_for_device = c6x_dma_sync_single_for_device,
|
|
.sync_single_for_cpu = c6x_dma_sync_single_for_cpu,
|
|
.sync_sg_for_device = c6x_dma_sync_sg_for_device,
|
|
.sync_sg_for_cpu = c6x_dma_sync_sg_for_cpu,
|
|
};
|
|
EXPORT_SYMBOL(c6x_dma_ops);
|
|
|
|
/* Number of entries preallocated for DMA-API debugging */
|
|
#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
|
|
|
|
static int __init dma_init(void)
|
|
{
|
|
dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
|
|
|
|
return 0;
|
|
}
|
|
fs_initcall(dma_init);
|