diff options
Diffstat (limited to 'drivers/block/xen-blkback/common.h')
| -rw-r--r-- | drivers/block/xen-blkback/common.h | 25 |
1 files changed, 17 insertions, 8 deletions
diff --git a/drivers/block/xen-blkback/common.h b/drivers/block/xen-blkback/common.h index 45a044a53..c929ae227 100644 --- a/drivers/block/xen-blkback/common.h +++ b/drivers/block/xen-blkback/common.h @@ -39,6 +39,7 @@ #include <asm/pgalloc.h> #include <asm/hypervisor.h> #include <xen/grant_table.h> +#include <xen/page.h> #include <xen/xenbus.h> #include <xen/interface/io/ring.h> #include <xen/interface/io/blkif.h> @@ -51,12 +52,20 @@ extern unsigned int xen_blkif_max_ring_order; */ #define MAX_INDIRECT_SEGMENTS 256 -#define SEGS_PER_INDIRECT_FRAME \ - (PAGE_SIZE/sizeof(struct blkif_request_segment)) +/* + * Xen use 4K pages. The guest may use different page size (4K or 64K) + * Number of Xen pages per segment + */ +#define XEN_PAGES_PER_SEGMENT (PAGE_SIZE / XEN_PAGE_SIZE) + +#define XEN_PAGES_PER_INDIRECT_FRAME \ + (XEN_PAGE_SIZE/sizeof(struct blkif_request_segment)) +#define SEGS_PER_INDIRECT_FRAME \ + (XEN_PAGES_PER_INDIRECT_FRAME / XEN_PAGES_PER_SEGMENT) + #define MAX_INDIRECT_PAGES \ ((MAX_INDIRECT_SEGMENTS + SEGS_PER_INDIRECT_FRAME - 1)/SEGS_PER_INDIRECT_FRAME) -#define INDIRECT_PAGES(_segs) \ - ((_segs + SEGS_PER_INDIRECT_FRAME - 1)/SEGS_PER_INDIRECT_FRAME) +#define INDIRECT_PAGES(_segs) DIV_ROUND_UP(_segs, XEN_PAGES_PER_INDIRECT_FRAME) /* Not a real protocol. Used to generate ring structs which contain * the elements common to all protocols only. This way we get a @@ -399,8 +408,8 @@ static inline void blkif_get_x86_32_req(struct blkif_request *dst, struct blkif_x86_32_request *src) { int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST, j; - dst->operation = src->operation; - switch (src->operation) { + dst->operation = READ_ONCE(src->operation); + switch (dst->operation) { case BLKIF_OP_READ: case BLKIF_OP_WRITE: case BLKIF_OP_WRITE_BARRIER: @@ -447,8 +456,8 @@ static inline void blkif_get_x86_64_req(struct blkif_request *dst, struct blkif_x86_64_request *src) { int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST, j; - dst->operation = src->operation; - switch (src->operation) { + dst->operation = READ_ONCE(src->operation); + switch (dst->operation) { case BLKIF_OP_READ: case BLKIF_OP_WRITE: case BLKIF_OP_WRITE_BARRIER: |