Hi,
On 21/05/2020 00:45, Stefano Stabellini wrote:
From: Stefano Stabellini <stefano.stabell...@xilinx.com>
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.
Like patch #8, this explains what the code is doing not why this is
necessary.
Signed-off-by: Stefano Stabellini <stefano.stabell...@xilinx.com>
---
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) &&
I believe this change is incorrect. The bfn is a frame based on Xen page
granularity (always 4K) while pfn_valid() is expecting a frame based on
the Kernel page granularity.
!dev_is_dma_coherent(dev));
}
Cheers,
--
Julien Grall
