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/*
* Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corporation
*
* Provide default implementations of the DMA mapping callbacks for
* directly mapped busses.
*/
#include <linux/device.h>
#include <linux/dma-direct.h>
#include <linux/dma-debug.h>
#include <linux/gfp.h>
#include <linux/memblock.h>
#include <linux/export.h>
#include <linux/pci.h>
#include <asm/vio.h>
#include <asm/bug.h>
#include <asm/machdep.h>
#include <asm/swiotlb.h>
#include <asm/iommu.h>
/*
* Generic direct DMA implementation
*
* This implementation supports a per-device offset that can be applied if
* the address at which memory is visible to devices is not 0. Platform code
* can set archdata.dma_data to an unsigned long holding the offset. By
* default the offset is PCI_DRAM_OFFSET.
*/
static u64 __maybe_unused get_pfn_limit(struct device *dev)
{
u64 pfn = (dev->coherent_dma_mask >> PAGE_SHIFT) + 1;
#ifdef CONFIG_SWIOTLB
if (dev->bus_dma_mask && dev->dma_ops == &powerpc_swiotlb_dma_ops)
pfn = min_t(u64, pfn, dev->bus_dma_mask >> PAGE_SHIFT);
#endif
return pfn;
}
#ifndef CONFIG_NOT_COHERENT_CACHE
void *__dma_nommu_alloc_coherent(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t flag,
unsigned long attrs)
{
void *ret;
struct page *page;
int node = dev_to_node(dev);
#ifdef CONFIG_FSL_SOC
u64 pfn = get_pfn_limit(dev);
int zone;
/*
* This code should be OK on other platforms, but we have drivers that
* don't set coherent_dma_mask. As a workaround we just ifdef it. This
* whole routine needs some serious cleanup.
*/
zone = dma_pfn_limit_to_zone(pfn);
if (zone < 0) {
dev_err(dev, "%s: No suitable zone for pfn %#llx\n",
__func__, pfn);
return NULL;
}
switch (zone) {
#ifdef CONFIG_ZONE_DMA
case ZONE_DMA:
flag |= GFP_DMA;
break;
#endif
};
#endif /* CONFIG_FSL_SOC */
page = alloc_pages_node(node, flag, get_order(size));
if (page == NULL)
return NULL;
ret = page_address(page);
memset(ret, 0, size);
*dma_handle = phys_to_dma(dev,__pa(ret));
return ret;
}
void __dma_nommu_free_coherent(struct device *dev, size_t size,
void *vaddr, dma_addr_t dma_handle,
unsigned long attrs)
{
free_pages((unsigned long)vaddr, get_order(size));
}
#endif /* !CONFIG_NOT_COHERENT_CACHE */
int dma_nommu_map_sg(struct device *dev, struct scatterlist *sgl,
int nents, enum dma_data_direction direction,
unsigned long attrs)
{
struct scatterlist *sg;
int i;
for_each_sg(sgl, sg, nents, i) {
sg->dma_address = phys_to_dma(dev, sg_phys(sg));
sg->dma_length = sg->length;
if (attrs & DMA_ATTR_SKIP_CPU_SYNC)
continue;
__dma_sync_page(sg_page(sg), sg->offset, sg->length, direction);
}
return nents;
}
static void dma_nommu_unmap_sg(struct device *dev, struct scatterlist *sgl,
int nents, enum dma_data_direction direction,
unsigned long attrs)
{
struct scatterlist *sg;
int i;
for_each_sg(sgl, sg, nents, i)
__dma_sync_page(sg_page(sg), sg->offset, sg->length, direction);
}
dma_addr_t dma_nommu_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size,
enum dma_data_direction dir, unsigned long attrs)
{
if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
__dma_sync_page(page, offset, size, dir);
return phys_to_dma(dev, page_to_phys(page)) + offset;
}
static inline void dma_nommu_unmap_page(struct device *dev,
dma_addr_t dma_address,
size_t size,
enum dma_data_direction direction,
unsigned long attrs)
{
if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
__dma_sync(bus_to_virt(dma_address), size, direction);
}
#ifdef CONFIG_NOT_COHERENT_CACHE
static inline void dma_nommu_sync_sg(struct device *dev,
struct scatterlist *sgl, int nents,
enum dma_data_direction direction)
{
struct scatterlist *sg;
int i;
for_each_sg(sgl, sg, nents, i)
__dma_sync_page(sg_page(sg), sg->offset, sg->length, direction);
}
static inline void dma_nommu_sync_single(struct device *dev,
dma_addr_t dma_handle, size_t size,
enum dma_data_direction direction)
{
__dma_sync(bus_to_virt(dma_handle), size, direction);
}
#endif
const struct dma_map_ops dma_nommu_ops = {
.alloc = __dma_nommu_alloc_coherent,
.free = __dma_nommu_free_coherent,
.map_sg = dma_nommu_map_sg,
.unmap_sg = dma_nommu_unmap_sg,
.dma_supported = dma_direct_supported,
.map_page = dma_nommu_map_page,
.unmap_page = dma_nommu_unmap_page,
.get_required_mask = dma_direct_get_required_mask,
#ifdef CONFIG_NOT_COHERENT_CACHE
.sync_single_for_cpu = dma_nommu_sync_single,
.sync_single_for_device = dma_nommu_sync_single,
.sync_sg_for_cpu = dma_nommu_sync_sg,
.sync_sg_for_device = dma_nommu_sync_sg,
#endif
};
EXPORT_SYMBOL(dma_nommu_ops);
static int __init dma_init(void)
{
#ifdef CONFIG_IBMVIO
dma_debug_add_bus(&vio_bus_type);
#endif
return 0;
}
fs_initcall(dma_init);
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