[PATCH v2 10/11] xen/arm: introduce phys/dma translations in xen_dma_sync_for_*

Stefano Stabellini
2020-06-03T22:23:01Z

From: Stefano Stabellini <stefano.stabellini@xilinx.com>

xen_dma_sync_for_cpu, xen_dma_sync_for_device, xen_arch_need_swiotlb are
getting called passing dma addresses. On some platforms dma addresses
could be different from physical addresses. Before doing any operations
on these addresses we need to convert them back to physical addresses
using dma_to_phys.

Add dma_to_phys calls to xen_dma_sync_for_cpu, xen_dma_sync_for_device,
and xen_arch_need_swiotlb.

dma_cache_maint is fixed by the next patch.

Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
Tested-by: Corey Minyard <cminyard@mvista.com>
Tested-by: Roman Shaposhnik <roman@zededa.com>

---
Changes in v2:
- improve commit message
- don't use pfn_valid
---
arch/arm/xen/mm.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c
index f2414ea40a79..bbad712a890d 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);
@@ -98,7 +99,7 @@ bool xen_arch_need_swiotlb(struct device *dev,
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
--
2.17.1