Re: [PATCH 08/13] swiotlb-xen: always use dma-direct helpers to alloc coherent pages

2019-09-04 Thread Christoph Hellwig 
On Tue, Sep 03, 2019 at 06:25:54PM -0400, Boris Ostrovsky wrote:
> > If I am reading __dma_direct_alloc_pages() correctly there is a path
> > that will force us to use GFP_DMA32 and as Juergen pointed out in
> > another message that may not be desirable.

Yes, it will add GFP_DMA32.  So I guess for now we'll just keep the
direct page allocator calls and resend.  I don't think this is the
right thing to do long term, but I'd really like to get this series
finished.

Re: [PATCH 08/13] swiotlb-xen: always use dma-direct helpers to alloc coherent pages

2019-09-03 Thread Boris Ostrovsky 
(Now with correct address for Juergen)

On 9/3/19 6:15 PM, Boris Ostrovsky wrote:
> On 9/2/19 9:03 AM, Christoph Hellwig wrote:
>> diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
>> index b8808677ae1d..f9dd4cb6e4b3 100644
>> --- a/drivers/xen/swiotlb-xen.c
>> +++ b/drivers/xen/swiotlb-xen.c
>> @@ -299,8 +299,7 @@ xen_swiotlb_alloc_coherent(struct device *hwdev, size_t 
>> size,
>>   * address. In fact on ARM virt_to_phys only works for kernel direct
>>   * mapped RAM memory. Also see comment below.
>>   */
>> -ret = xen_alloc_coherent_pages(hwdev, size, dma_handle, flags, attrs);
>> -
>> +ret = dma_direct_alloc(hwdev, size, dma_handle, flags, attrs);
>
> If I am reading __dma_direct_alloc_pages() correctly there is a path
> that will force us to use GFP_DMA32 and as Juergen pointed out in
> another message that may not be desirable.
>
> -boris
>
>
>

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Re: [PATCH 08/13] swiotlb-xen: always use dma-direct helpers to alloc coherent pages

2019-09-03 Thread Boris Ostrovsky 
On 9/2/19 9:03 AM, Christoph Hellwig wrote:
> diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
> index b8808677ae1d..f9dd4cb6e4b3 100644
> --- a/drivers/xen/swiotlb-xen.c
> +++ b/drivers/xen/swiotlb-xen.c
> @@ -299,8 +299,7 @@ xen_swiotlb_alloc_coherent(struct device *hwdev, size_t 
> size,
>* address. In fact on ARM virt_to_phys only works for kernel direct
>* mapped RAM memory. Also see comment below.
>*/
> - ret = xen_alloc_coherent_pages(hwdev, size, dma_handle, flags, attrs);
> -
> + ret = dma_direct_alloc(hwdev, size, dma_handle, flags, attrs);


If I am reading __dma_direct_alloc_pages() correctly there is a path
that will force us to use GFP_DMA32 and as Juergen pointed out in
another message that may not be desirable.

-boris

[PATCH 08/13] swiotlb-xen: always use dma-direct helpers to alloc coherent pages

2019-09-02 Thread Christoph Hellwig 
x86 currently calls alloc_pages, but using dma-direct works as well
there, with the added benefit of using the CMA pool if available.
The biggest advantage is of course to remove a pointless bit of
architecture specific code.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Stefano Stabellini 
---
 arch/x86/include/asm/xen/page-coherent.h | 16 
 drivers/xen/swiotlb-xen.c|  7 +++
 include/xen/arm/page-coherent.h  | 12 
 3 files changed, 3 insertions(+), 32 deletions(-)

diff --git a/arch/x86/include/asm/xen/page-coherent.h 
b/arch/x86/include/asm/xen/page-coherent.h
index 116777e7f387..8ee33c5edded 100644
--- a/arch/x86/include/asm/xen/page-coherent.h
+++ b/arch/x86/include/asm/xen/page-coherent.h
@@ -5,22 +5,6 @@
 #include 
 #include 
 
-static inline void *xen_alloc_coherent_pages(struct device *hwdev, size_t size,
-   dma_addr_t *dma_handle, gfp_t flags,
-   unsigned long attrs)
-{
-   void *vstart = (void*)__get_free_pages(flags, get_order(size));
-   *dma_handle = virt_to_phys(vstart);
-   return vstart;
-}
-
-static inline void xen_free_coherent_pages(struct device *hwdev, size_t size,
-   void *cpu_addr, dma_addr_t dma_handle,
-   unsigned long attrs)
-{
-   free_pages((unsigned long) cpu_addr, get_order(size));
-}
-
 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, unsigned long attrs) { }
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index b8808677ae1d..f9dd4cb6e4b3 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -299,8 +299,7 @@ xen_swiotlb_alloc_coherent(struct device *hwdev, size_t 
size,
 * address. In fact on ARM virt_to_phys only works for kernel direct
 * mapped RAM memory. Also see comment below.
 */
-   ret = xen_alloc_coherent_pages(hwdev, size, dma_handle, flags, attrs);
-
+   ret = dma_direct_alloc(hwdev, size, dma_handle, flags, attrs);
if (!ret)
return ret;
 
@@ -319,7 +318,7 @@ xen_swiotlb_alloc_coherent(struct device *hwdev, size_t 
size,
else {
if (xen_create_contiguous_region(phys, order,
 fls64(dma_mask), dma_handle) 
!= 0) {
-   xen_free_coherent_pages(hwdev, size, ret, 
(dma_addr_t)phys, attrs);
+   dma_direct_free(hwdev, size, ret, (dma_addr_t)phys, 
attrs);
return NULL;
}
SetPageXenRemapped(virt_to_page(ret));
@@ -351,7 +350,7 @@ xen_swiotlb_free_coherent(struct device *hwdev, size_t 
size, void *vaddr,
TestClearPageXenRemapped(virt_to_page(vaddr)))
xen_destroy_contiguous_region(phys, order);
 
-   xen_free_coherent_pages(hwdev, size, vaddr, (dma_addr_t)phys, attrs);
+   dma_direct_free(hwdev, size, vaddr, (dma_addr_t)phys, attrs);
 }
 
 /*
diff --git a/include/xen/arm/page-coherent.h b/include/xen/arm/page-coherent.h
index a840d6949a87..0e244f4fec1a 100644
--- a/include/xen/arm/page-coherent.h
+++ b/include/xen/arm/page-coherent.h
@@ -16,18 +16,6 @@ void __xen_dma_sync_single_for_cpu(struct device *hwdev,
 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, unsigned long attrs)
-{
-   return dma_direct_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, unsigned long attrs)
-{
-   dma_direct_free(hwdev, size, cpu_addr, dma_handle, 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)
 {
-- 
2.20.1