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sd: Switch to byte-based block access

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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 :)
In fact, we no longer need to include 'buf' in the migration
stream (although we do have to ensure that the stream remains
compatible).

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Eric Blake 2016-05-06 10:26:39 -06:00 committed by Kevin Wolf
parent 098e732dbe
commit 12c125cba9
1 changed files with 4 additions and 47 deletions
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51
hw/sd/sd.c
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@ -123,7 +123,6 @@ struct SDState {
qemu_irq readonly_cb;
qemu_irq inserted_cb;
BlockBackend *blk;
uint8_t *buf;
bool enable;
};
@ -551,7 +550,7 @@ static const VMStateDescription sd_vmstate = {
VMSTATE_UINT64(data_start, SDState),
VMSTATE_UINT32(data_offset, SDState),
VMSTATE_UINT8_ARRAY(data, SDState, 512),
VMSTATE_BUFFER_POINTER_UNSAFE(buf, SDState, 1, 512),
VMSTATE_UNUSED_V(1, 512),
VMSTATE_BOOL(enable, SDState),
VMSTATE_END_OF_LIST()
},
@ -1577,57 +1576,17 @@ 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->data, len, 0) < 0) {
fprintf(stderr, "sd_blk_write: write error on host side\n");
}
}
@ -1925,8 +1884,6 @@ static void sd_realize(DeviceState *dev, Error **errp)
return;
}
sd->buf = blk_blockalign(sd->blk, 512);
if (sd->blk) {
blk_set_dev_ops(sd->blk, &sd_block_ops, sd);
}