linux/arch/arm/include/asm/xen/page-coherent.h
Stefano Stabellini 3567258d28 xen/arm: use hypercall to flush caches in map_page
In xen_dma_map_page, if the page is a local page, call the native
map_page dma_ops. If the page is foreign, call __xen_dma_map_page that
issues any required cache maintenane operations via hypercall.

The reason for doing this is that the native dma_ops map_page could
allocate buffers than need to be freed. If the page is foreign we don't
call the native unmap_page dma_ops function, resulting in a memory leak.

Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
2014-12-04 12:41:52 +00:00

88 lines
3.2 KiB
C

#ifndef _ASM_ARM_XEN_PAGE_COHERENT_H
#define _ASM_ARM_XEN_PAGE_COHERENT_H
#include <asm/page.h>
#include <linux/dma-attrs.h>
#include <linux/dma-mapping.h>
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);
void __xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
size_t size, enum dma_data_direction dir,
struct dma_attrs *attrs);
void __xen_dma_sync_single_for_cpu(struct device *hwdev,
dma_addr_t handle, size_t size, enum dma_data_direction dir);
void __xen_dma_sync_single_for_device(struct device *hwdev,
dma_addr_t handle, size_t size, enum dma_data_direction dir);
static inline void *xen_alloc_coherent_pages(struct device *hwdev, size_t size,
dma_addr_t *dma_handle, gfp_t flags,
struct dma_attrs *attrs)
{
return __generic_dma_ops(hwdev)->alloc(hwdev, size, dma_handle, flags, attrs);
}
static inline void xen_free_coherent_pages(struct device *hwdev, size_t size,
void *cpu_addr, dma_addr_t dma_handle,
struct dma_attrs *attrs)
{
__generic_dma_ops(hwdev)->free(hwdev, size, cpu_addr, dma_handle, attrs);
}
static inline 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)
{
bool local = PFN_DOWN(dev_addr) == page_to_pfn(page);
/* Dom0 is mapped 1:1, so if pfn == mfn the page is local otherwise
* is a foreign page grant-mapped in dom0. If the page is local we
* can safely call the native dma_ops function, otherwise we call
* the xen specific function. */
if (local)
__generic_dma_ops(hwdev)->map_page(hwdev, page, offset, size, dir, attrs);
else
__xen_dma_map_page(hwdev, page, dev_addr, offset, size, dir, attrs);
}
static inline void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
size_t size, enum dma_data_direction dir,
struct dma_attrs *attrs)
{
unsigned long pfn = PFN_DOWN(handle);
/* Dom0 is mapped 1:1, so calling pfn_valid on a foreign mfn will
* always return false. If the page is local we can safely call the
* native dma_ops function, otherwise we call the xen specific
* function. */
if (pfn_valid(pfn)) {
if (__generic_dma_ops(hwdev)->unmap_page)
__generic_dma_ops(hwdev)->unmap_page(hwdev, handle, size, dir, attrs);
} else
__xen_dma_unmap_page(hwdev, handle, size, dir, attrs);
}
static inline void xen_dma_sync_single_for_cpu(struct device *hwdev,
dma_addr_t handle, size_t size, enum dma_data_direction dir)
{
unsigned long pfn = PFN_DOWN(handle);
if (pfn_valid(pfn)) {
if (__generic_dma_ops(hwdev)->sync_single_for_cpu)
__generic_dma_ops(hwdev)->sync_single_for_cpu(hwdev, handle, size, dir);
} else
__xen_dma_sync_single_for_cpu(hwdev, handle, size, dir);
}
static inline void xen_dma_sync_single_for_device(struct device *hwdev,
dma_addr_t handle, size_t size, enum dma_data_direction dir)
{
unsigned long pfn = PFN_DOWN(handle);
if (pfn_valid(pfn)) {
if (__generic_dma_ops(hwdev)->sync_single_for_device)
__generic_dma_ops(hwdev)->sync_single_for_device(hwdev, handle, size, dir);
} else
__xen_dma_sync_single_for_device(hwdev, handle, size, dir);
}
#endif /* _ASM_ARM_XEN_PAGE_COHERENT_H */