2020-05-20 23:47:34

by Stefano Stabellini

Subject: [PATCH 10/10] xen/arm: call dma_to_phys on the dma_addr_t parameter of dma_cache_maint

From: Stefano Stabellini <[email protected]>

Add a struct device* parameter to dma_cache_maint.

Translate the dma_addr_t parameter of dma_cache_maint by calling
dma_to_phys. Do it for the first page and all the following pages, in
case of multipage handling.

Signed-off-by: Stefano Stabellini <[email protected]>
---
arch/arm/xen/mm.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c
index 7639251bcc79..6ddf3b3c1ab5 100644
--- a/arch/arm/xen/mm.c
+++ b/arch/arm/xen/mm.c
@@ -43,15 +43,18 @@ unsigned long xen_get_swiotlb_free_pages(unsigned int order)
static bool hypercall_cflush = false;

/* buffers in highmem or foreign pages cannot cross page boundaries */
-static void dma_cache_maint(dma_addr_t handle, size_t size, u32 op)
+static void dma_cache_maint(struct device *dev, dma_addr_t handle,
+ size_t size, u32 op)
{
struct gnttab_cache_flush cflush;

- cflush.a.dev_bus_addr = handle & XEN_PAGE_MASK;
cflush.offset = xen_offset_in_page(handle);
cflush.op = op;
+ handle &= XEN_PAGE_MASK;

do {
+ cflush.a.dev_bus_addr = dma_to_phys(dev, handle);
+
if (size + cflush.offset > XEN_PAGE_SIZE)
cflush.length = XEN_PAGE_SIZE - cflush.offset;
else
@@ -60,7 +63,7 @@ static void dma_cache_maint(dma_addr_t handle, size_t size, u32 op)
HYPERVISOR_grant_table_op(GNTTABOP_cache_flush, &cflush, 1);

cflush.offset = 0;
- cflush.a.dev_bus_addr += cflush.length;
+ handle += cflush.length;
size -= cflush.length;
} while (size);
}
@@ -79,7 +82,7 @@ void xen_dma_sync_for_cpu(struct device *dev, dma_addr_t 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);
+ dma_cache_maint(dev, handle, size, GNTTAB_CACHE_INVAL);
}

void xen_dma_sync_for_device(struct device *dev, dma_addr_t handle,
@@ -89,9 +92,9 @@ void xen_dma_sync_for_device(struct device *dev, dma_addr_t 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);
+ dma_cache_maint(dev, handle, size, GNTTAB_CACHE_INVAL);
else
- dma_cache_maint(handle, size, GNTTAB_CACHE_CLEAN);
+ dma_cache_maint(dev, handle, size, GNTTAB_CACHE_CLEAN);
}

bool xen_arch_need_swiotlb(struct device *dev,
--
2.17.1

2020-05-21 08:30:14

by Julien Grall

Subject: Re: [PATCH 10/10] xen/arm: call dma_to_phys on the dma_addr_t parameter of dma_cache_maint

On 21/05/2020 00:45, Stefano Stabellini wrote:
> From: Stefano Stabellini <[email protected]>
>
> Add a struct device* parameter to dma_cache_maint.
>
> Translate the dma_addr_t parameter of dma_cache_maint by calling
> dma_to_phys. Do it for the first page and all the following pages, in
> case of multipage handling.

The term 'page' is confusing here. Are we referring to Xen page or Linux
page?

Also, same as patch #8 and #9 regarding the commit message.

>
> Signed-off-by: Stefano Stabellini <[email protected]>
> ---
> arch/arm/xen/mm.c | 15 +++++++++------
> 1 file changed, 9 insertions(+), 6 deletions(-)
>
> diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c
> index 7639251bcc79..6ddf3b3c1ab5 100644
> --- a/arch/arm/xen/mm.c
> +++ b/arch/arm/xen/mm.c
> @@ -43,15 +43,18 @@ unsigned long xen_get_swiotlb_free_pages(unsigned int order)
> static bool hypercall_cflush = false;
>
> /* buffers in highmem or foreign pages cannot cross page boundaries */
> -static void dma_cache_maint(dma_addr_t handle, size_t size, u32 op)
> +static void dma_cache_maint(struct device *dev, dma_addr_t handle,
> + size_t size, u32 op)
> {
> struct gnttab_cache_flush cflush;
>
> - cflush.a.dev_bus_addr = handle & XEN_PAGE_MASK;
> cflush.offset = xen_offset_in_page(handle);
> cflush.op = op;
> + handle &= XEN_PAGE_MASK;
>
> do {
> + cflush.a.dev_bus_addr = dma_to_phys(dev, handle);
> +
> if (size + cflush.offset > XEN_PAGE_SIZE)
> cflush.length = XEN_PAGE_SIZE - cflush.offset;
> else
> @@ -60,7 +63,7 @@ static void dma_cache_maint(dma_addr_t handle, size_t size, u32 op)
> HYPERVISOR_grant_table_op(GNTTABOP_cache_flush, &cflush, 1);
>
> cflush.offset = 0;
> - cflush.a.dev_bus_addr += cflush.length;
> + handle += cflush.length;
> size -= cflush.length;
> } while (size);
> }
> @@ -79,7 +82,7 @@ void xen_dma_sync_for_cpu(struct device *dev, dma_addr_t 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);
> + dma_cache_maint(dev, handle, size, GNTTAB_CACHE_INVAL);
> }
>
> void xen_dma_sync_for_device(struct device *dev, dma_addr_t handle,
> @@ -89,9 +92,9 @@ void xen_dma_sync_for_device(struct device *dev, dma_addr_t 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);
> + dma_cache_maint(dev, handle, size, GNTTAB_CACHE_INVAL);
> else
> - dma_cache_maint(handle, size, GNTTAB_CACHE_CLEAN);
> + dma_cache_maint(dev, handle, size, GNTTAB_CACHE_CLEAN);
> }
>
> bool xen_arch_need_swiotlb(struct device *dev,
>

Cheers,

--
Julien Grall