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#include <linux/cpu.h>
#include <linux/dma-mapping.h>
#include <linux/gfp.h>
#include <linux/highmem.h>
#include <xen/features.h>
enum dma_cache_op {
DMA_UNMAP,
DMA_MAP,
};
/* functions called by SWIOTLB */
static void dma_cache_maint(dma_addr_t handle, unsigned long offset,
size_t size, enum dma_data_direction dir, enum dma_cache_op op)
{
unsigned long pfn;
size_t left = size;
pfn = (handle >> PAGE_SHIFT) + offset / PAGE_SIZE;
offset %= PAGE_SIZE;
do {
size_t len = left;
/* TODO: cache flush */
offset = 0;
pfn++;
left -= len;
} while (left);
}
static void __xen_dma_page_dev_to_cpu(struct device *hwdev, dma_addr_t handle,
size_t size, enum dma_data_direction dir)
{
dma_cache_maint(handle & PAGE_MASK, handle & ~PAGE_MASK, size, dir, DMA_UNMAP);
}
static void __xen_dma_page_cpu_to_dev(struct device *hwdev, dma_addr_t handle,
size_t size, enum dma_data_direction dir)
{
dma_cache_maint(handle & PAGE_MASK, handle & ~PAGE_MASK, size, dir, DMA_MAP);
}
void __xen_dma_map_page(struct device *hwdev, struct page *page,
dma_addr_t dev_addr, unsigned long offset, size_t size,
enum dma_data_direction dir, struct dma_attrs *attrs)
{
if (is_device_dma_coherent(hwdev))
return;
if (dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs))
return;
__xen_dma_page_cpu_to_dev(hwdev, dev_addr, size, dir);
}
void __xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
size_t size, enum dma_data_direction dir,
struct dma_attrs *attrs)
{
if (is_device_dma_coherent(hwdev))
return;
if (dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs))
return;
__xen_dma_page_dev_to_cpu(hwdev, handle, size, dir);
}
void __xen_dma_sync_single_for_cpu(struct device *hwdev,
dma_addr_t handle, size_t size, enum dma_data_direction dir)
{
if (is_device_dma_coherent(hwdev))
return;
__xen_dma_page_dev_to_cpu(hwdev, handle, size, dir);
}
void __xen_dma_sync_single_for_device(struct device *hwdev,
dma_addr_t handle, size_t size, enum dma_data_direction dir)
{
if (is_device_dma_coherent(hwdev))
return;
__xen_dma_page_cpu_to_dev(hwdev, handle, size, dir);
}
int __init xen_mm32_init(void)
{
if (!xen_initial_domain())
return 0;
return 0;
}
arch_initcall(xen_mm32_init);
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