[Qemu-devel] [PATCH v4 06/14] sd: Switch to byte-based block access

[Eric Blake <eblake@redhat.com>]

Sector-based blk_write() should die; switch to byte-based
blk_pwrite() instead.  Likewise for blk_read().

Greatly simplifies the code, now that we let the block layer
take care of alignment and read-modify-write on our behalf :)

Signed-off-by: Eric Blake <eblake@redhat.com>
---
 hw/sd/sd.c | 46 +++-------------------------------------------
 1 file changed, 3 insertions(+), 43 deletions(-)

diff --git a/hw/sd/sd.c b/hw/sd/sd.c
index b66e5d2..3c2f2f1 100644
--- a/hw/sd/sd.c
+++ b/hw/sd/sd.c
@@ -1577,57 +1577,17 @@ send_response:

 static void sd_blk_read(SDState *sd, uint64_t addr, uint32_t len)
 {
-    uint64_t end = addr + len;
-
     DPRINTF("sd_blk_read: addr = 0x%08llx, len = %d\n",
             (unsigned long long) addr, len);
-    if (!sd->blk || blk_read(sd->blk, addr >> 9, sd->buf, 1) < 0) {
+    if (!sd->blk || blk_pread(sd->blk, addr, sd->data, len) < 0) {
         fprintf(stderr, "sd_blk_read: read error on host side\n");
-        return;
     }
-
-    if (end > (addr & ~511) + 512) {
-        memcpy(sd->data, sd->buf + (addr & 511), 512 - (addr & 511));
-
-        if (blk_read(sd->blk, end >> 9, sd->buf, 1) < 0) {
-            fprintf(stderr, "sd_blk_read: read error on host side\n");
-            return;
-        }
-        memcpy(sd->data + 512 - (addr & 511), sd->buf, end & 511);
-    } else
-        memcpy(sd->data, sd->buf + (addr & 511), len);
 }

 static void sd_blk_write(SDState *sd, uint64_t addr, uint32_t len)
 {
-    uint64_t end = addr + len;
-
-    if ((addr & 511) || len < 512)
-        if (!sd->blk || blk_read(sd->blk, addr >> 9, sd->buf, 1) < 0) {
-            fprintf(stderr, "sd_blk_write: read error on host side\n");
-            return;
-        }
-
-    if (end > (addr & ~511) + 512) {
-        memcpy(sd->buf + (addr & 511), sd->data, 512 - (addr & 511));
-        if (blk_write(sd->blk, addr >> 9, sd->buf, 1) < 0) {
-            fprintf(stderr, "sd_blk_write: write error on host side\n");
-            return;
-        }
-
-        if (blk_read(sd->blk, end >> 9, sd->buf, 1) < 0) {
-            fprintf(stderr, "sd_blk_write: read error on host side\n");
-            return;
-        }
-        memcpy(sd->buf, sd->data + 512 - (addr & 511), end & 511);
-        if (blk_write(sd->blk, end >> 9, sd->buf, 1) < 0) {
-            fprintf(stderr, "sd_blk_write: write error on host side\n");
-        }
-    } else {
-        memcpy(sd->buf + (addr & 511), sd->data, len);
-        if (!sd->blk || blk_write(sd->blk, addr >> 9, sd->buf, 1) < 0) {
-            fprintf(stderr, "sd_blk_write: write error on host side\n");
-        }
+    if (!sd->blk || blk_pwrite(sd->blk, addr, sd->buf, len, 0) < 0) {
+        fprintf(stderr, "sd_blk_write: write error on host side\n");
     }
 }

-- 
2.5.5