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xtensa: reimplement DMA API using common helpers

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- keep existing functionality: don't handle attributes, don't support
  high memory;
- implement scatterlist primitives (map/unmap/sync);
- enable DMA API debug.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
This commit is contained in:
Max Filippov
2015-05-25 06:55:05 +03:00
parent 4229fb12a0
commit c75959a6da
5 changed files with 239 additions and 184 deletions
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205
arch/xtensa/kernel/pci-dma.c
View File

@@ -1,6 +1,4 @@
/*
* arch/xtensa/kernel/pci-dma.c
*
* DMA coherent memory allocation.
*
* This program is free software; you can redistribute it and/or modify it
@@ -9,6 +7,7 @@
* option) any later version.
*
* Copyright (C) 2002 - 2005 Tensilica Inc.
* Copyright (C) 2015 Cadence Design Systems Inc.
*
* Based on version for i386.
*
@@ -25,13 +24,107 @@
#include <asm/io.h>
#include <asm/cacheflush.h>
void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
enum dma_data_direction dir)
{
switch (dir) {
case DMA_BIDIRECTIONAL:
__flush_invalidate_dcache_range((unsigned long)vaddr, size);
break;
case DMA_FROM_DEVICE:
__invalidate_dcache_range((unsigned long)vaddr, size);
break;
case DMA_TO_DEVICE:
__flush_dcache_range((unsigned long)vaddr, size);
break;
case DMA_NONE:
BUG();
break;
}
}
EXPORT_SYMBOL(dma_cache_sync);
static void xtensa_sync_single_for_cpu(struct device *dev,
dma_addr_t dma_handle, size_t size,
enum dma_data_direction dir)
{
void *vaddr;
switch (dir) {
case DMA_BIDIRECTIONAL:
case DMA_FROM_DEVICE:
vaddr = bus_to_virt(dma_handle);
__invalidate_dcache_range((unsigned long)vaddr, size);
break;
case DMA_NONE:
BUG();
break;
default:
break;
}
}
static void xtensa_sync_single_for_device(struct device *dev,
dma_addr_t dma_handle, size_t size,
enum dma_data_direction dir)
{
void *vaddr;
switch (dir) {
case DMA_BIDIRECTIONAL:
case DMA_TO_DEVICE:
vaddr = bus_to_virt(dma_handle);
__flush_dcache_range((unsigned long)vaddr, size);
break;
case DMA_NONE:
BUG();
break;
default:
break;
}
}
static void xtensa_sync_sg_for_cpu(struct device *dev,
struct scatterlist *sg, int nents,
enum dma_data_direction dir)
{
struct scatterlist *s;
int i;
for_each_sg(sg, s, nents, i) {
xtensa_sync_single_for_cpu(dev, sg_dma_address(s),
sg_dma_len(s), dir);
}
}
static void xtensa_sync_sg_for_device(struct device *dev,
struct scatterlist *sg, int nents,
enum dma_data_direction dir)
{
struct scatterlist *s;
int i;
for_each_sg(sg, s, nents, i) {
xtensa_sync_single_for_device(dev, sg_dma_address(s),
sg_dma_len(s), dir);
}
}
/*
* Note: We assume that the full memory space is always mapped to 'kseg'
* Otherwise we have to use page attributes (not implemented).
*/
void *
dma_alloc_coherent(struct device *dev,size_t size,dma_addr_t *handle,gfp_t flag)
static void *xtensa_dma_alloc(struct device *dev, size_t size,
dma_addr_t *handle, gfp_t flag,
struct dma_attrs *attrs)
{
unsigned long ret;
unsigned long uncached = 0;
@@ -52,20 +145,15 @@ dma_alloc_coherent(struct device *dev,size_t size,dma_addr_t *handle,gfp_t flag)
BUG_ON(ret < XCHAL_KSEG_CACHED_VADDR ||
ret > XCHAL_KSEG_CACHED_VADDR + XCHAL_KSEG_SIZE - 1);
uncached = ret + XCHAL_KSEG_BYPASS_VADDR - XCHAL_KSEG_CACHED_VADDR;
*handle = virt_to_bus((void *)ret);
__invalidate_dcache_range(ret, size);
if (ret != 0) {
memset((void*) ret, 0, size);
uncached = ret+XCHAL_KSEG_BYPASS_VADDR-XCHAL_KSEG_CACHED_VADDR;
*handle = virt_to_bus((void*)ret);
__flush_invalidate_dcache_range(ret, size);
}
return (void*)uncached;
return (void *)uncached;
}
EXPORT_SYMBOL(dma_alloc_coherent);
void dma_free_coherent(struct device *hwdev, size_t size,
void *vaddr, dma_addr_t dma_handle)
static void xtensa_dma_free(struct device *hwdev, size_t size, void *vaddr,
dma_addr_t dma_handle, struct dma_attrs *attrs)
{
unsigned long addr = (unsigned long)vaddr +
XCHAL_KSEG_CACHED_VADDR - XCHAL_KSEG_BYPASS_VADDR;
@@ -75,24 +163,79 @@ void dma_free_coherent(struct device *hwdev, size_t size,
free_pages(addr, get_order(size));
}
EXPORT_SYMBOL(dma_free_coherent);
void consistent_sync(void *vaddr, size_t size, int direction)
static dma_addr_t xtensa_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size,
enum dma_data_direction dir,
struct dma_attrs *attrs)
{
switch (direction) {
case PCI_DMA_NONE:
BUG();
case PCI_DMA_FROMDEVICE: /* invalidate only */
__invalidate_dcache_range((unsigned long)vaddr,
(unsigned long)size);
break;
dma_addr_t dma_handle = page_to_phys(page) + offset;
case PCI_DMA_TODEVICE: /* writeback only */
case PCI_DMA_BIDIRECTIONAL: /* writeback and invalidate */
__flush_invalidate_dcache_range((unsigned long)vaddr,
(unsigned long)size);
break;
BUG_ON(PageHighMem(page));
xtensa_sync_single_for_device(dev, dma_handle, size, dir);
return dma_handle;
}
static void xtensa_unmap_page(struct device *dev, dma_addr_t dma_handle,
size_t size, enum dma_data_direction dir,
struct dma_attrs *attrs)
{
xtensa_sync_single_for_cpu(dev, dma_handle, size, dir);
}
static int xtensa_map_sg(struct device *dev, struct scatterlist *sg,
int nents, enum dma_data_direction dir,
struct dma_attrs *attrs)
{
struct scatterlist *s;
int i;
for_each_sg(sg, s, nents, i) {
s->dma_address = xtensa_map_page(dev, sg_page(s), s->offset,
s->length, dir, attrs);
}
return nents;
}
static void xtensa_unmap_sg(struct device *dev,
struct scatterlist *sg, int nents,
enum dma_data_direction dir,
struct dma_attrs *attrs)
{
struct scatterlist *s;
int i;
for_each_sg(sg, s, nents, i) {
xtensa_unmap_page(dev, sg_dma_address(s),
sg_dma_len(s), dir, attrs);
}
}
EXPORT_SYMBOL(consistent_sync);
int xtensa_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
{
return 0;
}
struct dma_map_ops xtensa_dma_map_ops = {
.alloc = xtensa_dma_alloc,
.free = xtensa_dma_free,
.map_page = xtensa_map_page,
.unmap_page = xtensa_unmap_page,
.map_sg = xtensa_map_sg,
.unmap_sg = xtensa_unmap_sg,
.sync_single_for_cpu = xtensa_sync_single_for_cpu,
.sync_single_for_device = xtensa_sync_single_for_device,
.sync_sg_for_cpu = xtensa_sync_sg_for_cpu,
.sync_sg_for_device = xtensa_sync_sg_for_device,
.mapping_error = xtensa_dma_mapping_error,
};
EXPORT_SYMBOL(xtensa_dma_map_ops);
#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
static int __init xtensa_dma_init(void)
{
dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
return 0;
}
fs_initcall(xtensa_dma_init);