[PATCH 09/10] xen/arm: introduce phys/dma translations in xen_dma_sync_for_*

From: Stefano Stabellini
Date: Wed May 20 2020 - 19:45:29 EST


From: Stefano Stabellini <stefano.stabellini@xxxxxxxxxx>

Add phys_to_dma/dma_to_phys calls to
xen_dma_sync_for_cpu, xen_dma_sync_for_device, and
xen_arch_need_swiotlb.

In xen_arch_need_swiotlb, take the opportunity to switch to the simpler
pfn_valid check we use everywhere else.

dma_cache_maint is fixed by the next patch.

Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxx>
---
arch/arm/xen/mm.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c
index f2414ea40a79..7639251bcc79 100644
--- a/arch/arm/xen/mm.c
+++ b/arch/arm/xen/mm.c
@@ -1,5 +1,6 @@
// SPDX-License-Identifier: GPL-2.0-only
#include <linux/cpu.h>
+#include <linux/dma-direct.h>
#include <linux/dma-noncoherent.h>
#include <linux/gfp.h>
#include <linux/highmem.h>
@@ -75,7 +76,7 @@ void xen_dma_sync_for_cpu(struct device *dev, dma_addr_t handle,
phys_addr_t paddr, size_t size,
enum dma_data_direction dir)
{
- if (pfn_valid(PFN_DOWN(handle)))
+ if (pfn_valid(PFN_DOWN(dma_to_phys(dev, handle))))
arch_sync_dma_for_cpu(paddr, size, dir);
else if (dir != DMA_TO_DEVICE)
dma_cache_maint(handle, size, GNTTAB_CACHE_INVAL);
@@ -85,7 +86,7 @@ void xen_dma_sync_for_device(struct device *dev, dma_addr_t handle,
phys_addr_t paddr, size_t size,
enum dma_data_direction dir)
{
- if (pfn_valid(PFN_DOWN(handle)))
+ if (pfn_valid(PFN_DOWN(dma_to_phys(dev, handle))))
arch_sync_dma_for_device(paddr, size, dir);
else if (dir == DMA_FROM_DEVICE)
dma_cache_maint(handle, size, GNTTAB_CACHE_INVAL);
@@ -97,8 +98,7 @@ bool xen_arch_need_swiotlb(struct device *dev,
phys_addr_t phys,
dma_addr_t dev_addr)
{
- unsigned int xen_pfn = XEN_PFN_DOWN(phys);
- unsigned int bfn = XEN_PFN_DOWN(dev_addr);
+ unsigned int bfn = XEN_PFN_DOWN(dma_to_phys(dev, dev_addr));

/*
* The swiotlb buffer should be used if
@@ -115,7 +115,7 @@ bool xen_arch_need_swiotlb(struct device *dev,
* require a bounce buffer because the device doesn't support coherent
* memory and we are not able to flush the cache.
*/
- return (!hypercall_cflush && (xen_pfn != bfn) &&
+ return (!hypercall_cflush && !pfn_valid(bfn) &&
!dev_is_dma_coherent(dev));
}

--
2.17.1