Commit 12c125cb authored by Eric Blake's avatar Eric Blake Committed by Kevin Wolf
Browse files

sd: Switch to byte-based block access 



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: default avatarEric Blake <eblake@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent 098e732d

hw/sd/sd.c

+4 −47
Original line number Diff line number Diff line
@@ -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) {

    if (!sd->blk || blk_pwrite(sd->blk, addr, sd->data, len, 0) < 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");

        }

    }

}
@@ -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);

    }