@@ -2577,7 +2577,8 @@ static int xen_exchange_memory(unsigned long extents_in, unsigned int order_in,
unsigned long extents_out,
unsigned int order_out,
unsigned long *mfns_out,
- unsigned int address_bits)
+ unsigned int address_bits,
+ bool size_align)
{
long rc;
int success;
@@ -2599,7 +2600,8 @@ static int xen_exchange_memory(unsigned long extents_in, unsigned int order_in,
};
BUG_ON(extents_in << order_in != extents_out << order_out);
-
+ if (size_align)
+ exchange.out.address_bits |= XENMEMF_align_size;
rc = HYPERVISOR_memory_op(XENMEM_exchange, &exchange);
success = (exchange.nr_exchanged == extents_in);
@@ -2611,7 +2613,7 @@ static int xen_exchange_memory(unsigned long extents_in, unsigned int order_in,
int xen_create_contiguous_region(phys_addr_t pstart, unsigned int order,
unsigned int address_bits,
- dma_addr_t *dma_handle)
+ dma_addr_t *dma_handle, bool size_align)
{
unsigned long *in_frames = discontig_frames, out_frame;
unsigned long flags;
@@ -2641,7 +2643,7 @@ int xen_create_contiguous_region(phys_addr_t pstart, unsigned int order,
out_frame = virt_to_pfn(vstart);
success = xen_exchange_memory(1UL << order, 0, in_frames,
1, order, &out_frame,
- address_bits);
+ address_bits, size_align);
/* 3. Map the new extent in place of old pages. */
if (success)
@@ -2682,7 +2684,7 @@ void xen_destroy_contiguous_region(phys_addr_t pstart, unsigned int order)
/* 3. Do the exchange for non-contiguous MFNs. */
success = xen_exchange_memory(1, order, &in_frame, 1UL << order,
- 0, out_frames, 0);
+ 0, out_frames, 0, false);
/* 4. Map new pages in place of old pages. */
if (success)
@@ -173,7 +173,7 @@ xen_swiotlb_fixup(void *buf, size_t size, unsigned long nslabs)
rc = xen_create_contiguous_region(
p + (i << IO_TLB_SHIFT),
get_order(slabs << IO_TLB_SHIFT),
- dma_bits, &dma_handle);
+ dma_bits, &dma_handle, false);
} while (rc && dma_bits++ < max_dma_bits);
if (rc)
return rc;
@@ -334,7 +334,7 @@ xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
*dma_handle = dev_addr;
else {
if (xen_create_contiguous_region(phys, order,
- fls64(dma_mask), dma_handle) != 0) {
+ fls64(dma_mask), dma_handle, true) != 0) {
xen_free_coherent_pages(hwdev, size, ret, (dma_addr_t)phys, attrs);
return NULL;
}
@@ -19,6 +19,16 @@
#define XENMEM_increase_reservation 0
#define XENMEM_decrease_reservation 1
#define XENMEM_populate_physmap 6
+/*
+ * Maximum # bits addressable by the user of the allocated region (e.g., I/O
+ * devices often have a 32-bit limitation even in 64-bit systems). If zero
+ * then the user has no addressing restriction. This field is not used by
+ * XENMEM_decrease_reservation.
+ */
+
+/* Flag to indicate the allocation to be size aligned. */
+#define XENMEMF_align_size (1U<<19)
+
struct xen_memory_reservation {
/*
@@ -36,7 +36,7 @@ int xen_setup_shutdown_event(void);
extern unsigned long *xen_contiguous_bitmap;
int xen_create_contiguous_region(phys_addr_t pstart, unsigned int order,
unsigned int address_bits,
- dma_addr_t *dma_handle);
+ dma_addr_t *dma_handle, bool size_align);
void xen_destroy_contiguous_region(phys_addr_t pstart, unsigned int order);
The dma_alloc_coherent() API specifies that: [...] The CPU virtual address and the DMA address are both guaranteed to be aligned to the smallest PAGE_SIZE order which is greater than or equal to the requested size. This invariant exists (for example) to guarantee that if you allocate a chunk which is smaller than or equal to 64 kilobytes, the extent of the buffer you receive will not cross a 64K boundary." This change, along with the XENMEMF_align_size in the hypervisor allows us to provide DMA buffers that are size aligned. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> --- arch/x86/xen/mmu.c | 12 +++++++----- drivers/xen/swiotlb-xen.c | 4 ++-- include/xen/interface/memory.h | 10 ++++++++++ include/xen/xen-ops.h | 2 +- 4 files changed, 20 insertions(+), 8 deletions(-)