On 05/31/2015 04:05 PM, Mark Cave-Ayland wrote:
> For better handling of unaligned block device accesses.
>
> Signed-off-by: Mark Cave-Ayland <mark.cave-ayl...@ilande.co.uk>
> ---
> hw/ide/macio.c | 102
> ++++++++++++++++++++++----------------------------------
> 1 file changed, 40 insertions(+), 62 deletions(-)
>
> diff --git a/hw/ide/macio.c b/hw/ide/macio.c
> index 585a27b..f1ac001 100644
> --- a/hw/ide/macio.c
> +++ b/hw/ide/macio.c
> @@ -52,7 +52,7 @@ static const int debug_macio = 0;
> #define MACIO_PAGE_SIZE 4096
>
> static void pmac_dma_read(BlockBackend *blk,
> - int64_t sector_num, int nb_sectors,
> + int64_t offset, unsigned int bytes,
> void (*cb)(void *opaque, int ret), void *opaque)
> {
> DBDMA_io *io = opaque;
> @@ -60,76 +60,48 @@ static void pmac_dma_read(BlockBackend *blk,
> IDEState *s = idebus_active_if(&m->bus);
> dma_addr_t dma_addr, dma_len;
> void *mem;
> - int nsector, remainder;
> + int64_t sector_num;
> + int nsector;
> + uint64_t align = BDRV_SECTOR_SIZE;
> + size_t head_bytes, tail_bytes;
>
> qemu_iovec_destroy(&io->iov);
> qemu_iovec_init(&io->iov, io->len / MACIO_PAGE_SIZE + 1);
>
> - if (io->remainder_len > 0) {
> - /* Return remainder of request */
> - int transfer = MIN(io->remainder_len, io->len);
> + sector_num = (offset >> 9);
> + nsector = (io->len >> 9);
>
> - MACIO_DPRINTF("--- DMA read pop - bounce addr: %p addr: %"
> - HWADDR_PRIx " remainder_len: %x\n",
> - &io->remainder + (0x200 - transfer), io->addr,
> - io->remainder_len);
> + MACIO_DPRINTF("--- DMA read transfer (0x%" HWADDR_PRIx ",0x%x): "
> + "sector_num: %ld, nsector: %d\n", io->addr, io->len,
> + sector_num, nsector);
>
> - cpu_physical_memory_write(io->addr,
> - &io->remainder + (0x200 - transfer),
> - transfer);
> + dma_addr = io->addr;
> + dma_len = io->len;
> + mem = dma_memory_map(&address_space_memory, dma_addr, &dma_len,
> + DMA_DIRECTION_FROM_DEVICE);
>
> - io->remainder_len -= transfer;
> - io->len -= transfer;
> - io->addr += transfer;
> + if (offset & (align - 1)) {
> + head_bytes = offset & (align - 1);
>
> - s->io_buffer_index += transfer;
> - s->io_buffer_size -= transfer;
> + MACIO_DPRINTF("--- DMA unaligned head: sector %ld, "
> + "discarding %ld bytes\n", sector_num, head_bytes);
>
> - if (io->remainder_len != 0) {
> - /* Still waiting for remainder */
> - return;
> - }
> + qemu_iovec_add(&io->iov, &io->remainder, head_bytes);
>
> - if (io->len == 0) {
> - MACIO_DPRINTF("--- finished all read processing; go and
> finish\n");
> - cb(opaque, 0);
> - return;
> - }
> + bytes += offset & (align - 1);
> + offset = offset & ~(align - 1);
> }
>
> - if (s->drive_kind == IDE_CD) {
> - sector_num = (int64_t)(s->lba << 2) + (s->io_buffer_index >> 9);
> - } else {
> - sector_num = ide_get_sector(s) + (s->io_buffer_index >> 9);
> - }
> + qemu_iovec_add(&io->iov, mem, io->len);
>
> - nsector = ((io->len + 0x1ff) >> 9);
> - remainder = (nsector << 9) - io->len;
> + if ((offset + bytes) & (align - 1)) {
> + tail_bytes = (offset + bytes) & (align - 1);
>
> - MACIO_DPRINTF("--- DMA read transfer - addr: %" HWADDR_PRIx " len: %x\n",
> - io->addr, io->len);
> -
> - dma_addr = io->addr;
> - dma_len = io->len;
> - mem = dma_memory_map(&address_space_memory, dma_addr, &dma_len,
> - DMA_DIRECTION_FROM_DEVICE);
> + MACIO_DPRINTF("--- DMA unaligned tail: sector %ld, "
> + "discarding bytes %ld\n", sector_num, tail_bytes);
>
> - if (!remainder) {
> - MACIO_DPRINTF("--- DMA read aligned - addr: %" HWADDR_PRIx
> - " len: %x\n", io->addr, io->len);
> - qemu_iovec_add(&io->iov, mem, io->len);
> - } else {
> - MACIO_DPRINTF("--- DMA read unaligned - addr: %" HWADDR_PRIx
> - " len: %x\n", io->addr, io->len);
> - qemu_iovec_add(&io->iov, mem, io->len);
> -
> - MACIO_DPRINTF("--- DMA read push - bounce addr: %p "
> - "remainder_len: %x\n",
> - &io->remainder + 0x200 - remainder, remainder);
> - qemu_iovec_add(&io->iov, &io->remainder + 0x200 - remainder,
> - remainder);
> -
> - io->remainder_len = remainder;
> + qemu_iovec_add(&io->iov, &io->remainder, align - tail_bytes);
> + bytes = ROUND_UP(bytes, align);
> }
>
> s->io_buffer_size -= io->len;
> @@ -137,11 +109,11 @@ static void pmac_dma_read(BlockBackend *blk,
>
> io->len = 0;
>
> - MACIO_DPRINTF("--- Block read transfer - sector_num: %"PRIx64" "
> - "nsector: %x\n",
> - sector_num, nsector);
> + MACIO_DPRINTF("--- Block read transfer - sector_num: %" PRIx64 " "
> + "nsector: %x\n", (offset >> 9), (bytes >> 9));
>
> - m->aiocb = blk_aio_readv(blk, sector_num, &io->iov, nsector, cb, io);
> + m->aiocb = blk_aio_readv(blk, (offset >> 9), &io->iov, (bytes >> 9),
> + cb, io);
> }
>
> static void pmac_dma_write(BlockBackend *blk,
> @@ -246,6 +218,7 @@ static void pmac_ide_atapi_transfer_cb(void *opaque, int
> ret)
> IDEState *s = idebus_active_if(&m->bus);
> int64_t sector_num;
> int nsector, remainder;
> + int64_t offset;
>
> MACIO_DPRINTF("\ns is %p\n", s);
> MACIO_DPRINTF("io_buffer_index: %x\n", s->io_buffer_index);
> @@ -294,10 +267,13 @@ static void pmac_ide_atapi_transfer_cb(void *opaque,
> int ret)
> nsector = (io->len + 0x1ff) >> 9;
> remainder = io->len & 0x1ff;
>
> + /* Calculate current offset */
> + offset = (int64_t)(s->lba << 11) + s->io_buffer_index;
> +
Bike shedding: Worth an ATAPI_BLOCK_SIZE_BITS define or similar? I guess
we don't really currently try to avoid magic constants for 512, 2048,
etc etc anywhere else, so ... nevermind. Just a project for a different
day. Forget I said anything.
> MACIO_DPRINTF("nsector: %d remainder: %x\n", nsector, remainder);
> MACIO_DPRINTF("sector: %"PRIx64" %zx\n", sector_num, io->iov.size /
> 512);
>
> - pmac_dma_read(s->blk, sector_num, nsector, pmac_ide_atapi_transfer_cb,
> io);
> + pmac_dma_read(s->blk, offset, io->len, pmac_ide_atapi_transfer_cb, io);
> return;
>
> done:
> @@ -315,6 +291,7 @@ static void pmac_ide_transfer_cb(void *opaque, int ret)
> IDEState *s = idebus_active_if(&m->bus);
> int64_t sector_num;
> int nsector, remainder;
> + int64_t offset;
>
> MACIO_DPRINTF("pmac_ide_transfer_cb\n");
>
> @@ -349,6 +326,7 @@ static void pmac_ide_transfer_cb(void *opaque, int ret)
>
> /* Calculate number of sectors */
> sector_num = ide_get_sector(s) + (s->io_buffer_index >> 9);
> + offset = (ide_get_sector(s) << 9) + s->io_buffer_index;
> nsector = (io->len + 0x1ff) >> 9;
> remainder = io->len & 0x1ff;
>
> @@ -359,7 +337,7 @@ static void pmac_ide_transfer_cb(void *opaque, int ret)
>
> switch (s->dma_cmd) {
> case IDE_DMA_READ:
> - pmac_dma_read(s->blk, sector_num, nsector, pmac_ide_transfer_cb, io);
> + pmac_dma_read(s->blk, offset, io->len, pmac_ide_transfer_cb, io);
> break;
> case IDE_DMA_WRITE:
> pmac_dma_write(s->blk, sector_num, nsector, pmac_ide_transfer_cb,
> io);
>
