/*
* DMA coherent memory allocation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* Copyright (C) 2002 - 2005 Tensilica Inc.
* Copyright (C) 2015 Cadence Design Systems Inc.
*
* Based on version for i386.
*
* Chris Zankel <chris@zankel.net>
* Joe Taylor <joe@tensilica.com, joetylr@yahoo.com>
*/
#include <linux/dma-contiguous.h>
#include <linux/gfp.h>
#include <linux/highmem.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/string.h>
#include <linux/types.h>
#include <asm/cacheflush.h>
#include <asm/io.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 do_cache_op(dma_addr_t dma_handle, size_t size,
void (*fn)(unsigned long, unsigned long))
{
unsigned long off = dma_handle & (PAGE_SIZE - 1);
unsigned long pfn = PFN_DOWN(dma_handle);
struct page *page = pfn_to_page(pfn);
if (!PageHighMem(page))
fn((unsigned long)bus_to_virt(dma_handle), size);
else
while (size > 0) {
size_t sz = min_t(size_t, size, PAGE_SIZE - off);
void *vaddr = kmap_atomic(page);
fn((unsigned long)vaddr + off, sz);
kunmap_atomic(vaddr);
off = 0;
++page;
size -= sz;
}
}
static void xtensa_sync_single_for_cpu(struct device *dev,
dma_addr_t dma_handle, size_t size,
enum dma_data_direction dir)
{
switch (dir) {
case DMA_BIDIRECTIONAL:
case DMA_FROM_DEVICE:
do_cache_op(dma_handle, size, __invalidate_dcache_range);
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)
{
switch (dir) {
case DMA_BIDIRECTIONAL:
case DMA_TO_DEVICE:
if (XCHAL_DCACHE_IS_WRITEBACK)
do_cache_op(dma_handle, size, __flush_dcache_range);
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).
*/
static void *xtensa_dma_alloc(struct device *dev, size_t size,
dma_addr_t *handle, gfp_t flag,
unsigned long attrs)
{
unsigned long ret;
unsigned long uncached = 0;
unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
struct page *page = NULL;
/* ignore region speicifiers */
flag &= ~(__GFP_DMA | __GFP_HIGHMEM);
if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff))
flag |= GFP_DMA;
if (gfpflags_allow_blocking(flag))
page = dma_alloc_from_contiguous(dev, count, get_order(size));
if (!page)
page = alloc_pages(flag, get_order(size));
if (!page)
return NULL;
ret = (unsigned long)page_address(page);
/* We currently don't support coherent memory outside KSEG */
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);
return (void *)uncached;
}
static void xtensa_dma_free(struct device *dev, size_t size, void *vaddr,
dma_addr_t dma_handle, unsigned long attrs)
{
unsigned long addr = (unsigned long)vaddr +
XCHAL_KSEG_CACHED_VADDR - XCHAL_KSEG_BYPASS_VADDR;
struct page *page = virt_to_page(addr);
unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
BUG_ON(addr < XCHAL_KSEG_CACHED_VADDR ||
addr > XCHAL_KSEG_CACHED_VADDR + XCHAL_KSEG_SIZE - 1);
if (!dma_release_from_contiguous(dev, page, count))
__free_pages(page, get_order(size));
}
static dma_addr_t xtensa_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 dma_handle = page_to_phys(page) + offset;
if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
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,
unsigned long attrs)
{
if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
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,
unsigned long 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,
unsigned long 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);
}
}
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);
