[PATCH v5 07/13] xen: make xen_create_contiguous_region return the dma address

From: Stefano Stabellini
Date: Thu Aug 29 2013 - 14:34:19 EST


Modify xen_create_contiguous_region to return the dma address of the
newly contiguous buffer.

Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
Reviewed-by: David Vrabel <david.vrabel@xxxxxxxxxx>


Changes in v4:
- use virt_to_machine instead of virt_to_bus.
---
arch/x86/xen/mmu.c | 4 +++-
drivers/xen/swiotlb-xen.c | 6 +++---
include/xen/xen-ops.h | 3 ++-
3 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index fdc3ba2..6c34d7c 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -2329,7 +2329,8 @@ static int xen_exchange_memory(unsigned long extents_in, unsigned int order_in,
}

int xen_create_contiguous_region(unsigned long vstart, unsigned int order,
- unsigned int address_bits)
+ unsigned int address_bits,
+ dma_addr_t *dma_handle)
{
unsigned long *in_frames = discontig_frames, out_frame;
unsigned long flags;
@@ -2368,6 +2369,7 @@ int xen_create_contiguous_region(unsigned long vstart, unsigned int order,

spin_unlock_irqrestore(&xen_reservation_lock, flags);

+ *dma_handle = virt_to_machine(vstart).maddr;
return success ? 0 : -ENOMEM;
}
EXPORT_SYMBOL_GPL(xen_create_contiguous_region);
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 1b2277c..b72f31c 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -126,6 +126,7 @@ xen_swiotlb_fixup(void *buf, size_t size, unsigned long nslabs)
{
int i, rc;
int dma_bits;
+ dma_addr_t dma_handle;

dma_bits = get_order(IO_TLB_SEGSIZE << IO_TLB_SHIFT) + PAGE_SHIFT;

@@ -137,7 +138,7 @@ xen_swiotlb_fixup(void *buf, size_t size, unsigned long nslabs)
rc = xen_create_contiguous_region(
(unsigned long)buf + (i << IO_TLB_SHIFT),
get_order(slabs << IO_TLB_SHIFT),
- dma_bits);
+ dma_bits, &dma_handle);
} while (rc && dma_bits++ < max_dma_bits);
if (rc)
return rc;
@@ -294,11 +295,10 @@ xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
*dma_handle = dev_addr;
else {
if (xen_create_contiguous_region(vstart, order,
- fls64(dma_mask)) != 0) {
+ fls64(dma_mask), dma_handle) != 0) {
free_pages(vstart, order);
return NULL;
}
- *dma_handle = virt_to_machine(ret).maddr;
}
memset(ret, 0, size);
return ret;
diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h
index d6fe062..9ef704d 100644
--- a/include/xen/xen-ops.h
+++ b/include/xen/xen-ops.h
@@ -20,7 +20,8 @@ int xen_setup_shutdown_event(void);

extern unsigned long *xen_contiguous_bitmap;
int xen_create_contiguous_region(unsigned long vstart, unsigned int order,
- unsigned int address_bits);
+ unsigned int address_bits,
+ dma_addr_t *dma_handle);

void xen_destroy_contiguous_region(unsigned long vstart, unsigned int order);

--
1.7.2.5

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