ide: commonize io_buffer_index initialization

Resetting the io_buffer_index to 0 is commonized,
with the exception of the case within ide_atapi_cmd_reply,
where we need to reset this index to 0 prior to the
ide_atapi_cmd_reply_end call.

Note that not all calls to ide_atapi_cmd_reply_end
expect the index to be 0, so setting it there is
not appropriate.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJohn Snow <jsnow@redhat.com>
Message-id: 1424708286-16483-12-git-send-email-jsnow@redhat.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

hw/ide/atapi.c

@@ -252,7 +252,6 @@ static void ide_atapi_cmd_reply(IDEState *s, int size, int max_size)
     s->packet_transfer_size = size;
     s->io_buffer_size = size;    /* dma: send the reply data as one chunk */
     s->elementary_transfer_size = 0;
-    s->io_buffer_index = 0;
 
     if (s->atapi_dma) {
         block_acct_start(blk_get_stats(s->blk), &s->acct, size,
@@ -261,6 +260,7 @@ static void ide_atapi_cmd_reply(IDEState *s, int size, int max_size)
         ide_start_dma(s, ide_atapi_cmd_read_dma_cb);
     } else {
         s->status = READY_STAT | SEEK_STAT;
+        s->io_buffer_index = 0;
         ide_atapi_cmd_reply_end(s);
     }
 }
@@ -368,7 +368,6 @@ static void ide_atapi_cmd_read_dma(IDEState *s, int lba, int nb_sectors,
 {
     s->lba = lba;
     s->packet_transfer_size = nb_sectors * sector_size;
-    s->io_buffer_index = 0;
     s->io_buffer_size = 0;
     s->cd_sector_size = sector_size;
 

hw/ide/core.c

@@ -780,7 +780,6 @@ eot:
 static void ide_sector_start_dma(IDEState *s, enum ide_dma_cmd dma_cmd)
 {
     s->status = READY_STAT | SEEK_STAT | DRQ_STAT | BUSY_STAT;
-    s->io_buffer_index = 0;
     s->io_buffer_size = 0;
     s->dma_cmd = dma_cmd;
 
@@ -802,6 +801,7 @@ static void ide_sector_start_dma(IDEState *s, enum ide_dma_cmd dma_cmd)
 
 void ide_start_dma(IDEState *s, BlockCompletionFunc *cb)
 {
+    s->io_buffer_index = 0;
     s->bus->retry_unit = s->unit;
     s->bus->retry_sector_num = ide_get_sector(s);
     s->bus->retry_nsector = s->nsector;
@@ -2341,7 +2341,6 @@ static void ide_restart_dma(IDEState *s, enum ide_dma_cmd dma_cmd)
     ide_set_sector(s, s->bus->retry_sector_num);
     s->nsector = s->bus->retry_nsector;
     s->bus->dma->ops->restart_dma(s->bus->dma);
-    s->io_buffer_index = 0;
     s->io_buffer_size = 0;
     s->dma_cmd = dma_cmd;
     ide_start_dma(s, ide_dma_cb);