[Qemu-devel] [PULL 2/6] macio: switch over to new byte-aligned DMA helpers

[John Snow <jsnow@redhat.com>]

From: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>

Now that the DMA helpers are byte-aligned they can be called directly from
the macio routines rather than emulating byte-aligned accesses via multiple
block-level accesses.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-Id: 1476445266-27503-3-git-send-email-mark.cave-ayland@ilande.co.uk
Signed-off-by: John Snow <jsnow@redhat.com>
---
 hw/ide/macio.c | 213 ++++++++-------------------------------------------------
 1 file changed, 28 insertions(+), 185 deletions(-)

diff --git a/hw/ide/macio.c b/hw/ide/macio.c
index 76f97c2..9742c00 100644
--- a/hw/ide/macio.c
+++ b/hw/ide/macio.c
@@ -52,187 +52,6 @@ static const int debug_macio = 0;
 
 #define MACIO_PAGE_SIZE 4096
 
-/*
- * Unaligned DMA read/write access functions required for OS X/Darwin which
- * don't perform DMA transactions on sector boundaries. These functions are
- * modelled on bdrv_co_preadv()/bdrv_co_pwritev() and so should be easy to
- * remove if the unaligned block APIs are ever exposed.
- */
-
-static void pmac_dma_read(BlockBackend *blk,
-                          int64_t offset, unsigned int bytes,
-                          void (*cb)(void *opaque, int ret), void *opaque)
-{
-    DBDMA_io *io = opaque;
-    MACIOIDEState *m = io->opaque;
-    IDEState *s = idebus_active_if(&m->bus);
-    dma_addr_t dma_addr;
-    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);
-
-    sector_num = (offset >> 9);
-    nsector = (io->len >> 9);
-
-    MACIO_DPRINTF("--- DMA read transfer (0x%" HWADDR_PRIx ",0x%x): "
-                  "sector_num: %" PRId64 ", nsector: %d\n", io->addr, io->len,
-                  sector_num, nsector);
-
-    dma_addr = io->addr;
-    io->dir = DMA_DIRECTION_FROM_DEVICE;
-    io->dma_len = io->len;
-    io->dma_mem = dma_memory_map(&address_space_memory, dma_addr, &io->dma_len,
-                                 io->dir);
-
-    if (offset & (align - 1)) {
-        head_bytes = offset & (align - 1);
-
-        MACIO_DPRINTF("--- DMA unaligned head: sector %" PRId64 ", "
-                      "discarding %zu bytes\n", sector_num, head_bytes);
-
-        qemu_iovec_add(&io->iov, &io->head_remainder, head_bytes);
-
-        bytes += offset & (align - 1);
-        offset = offset & ~(align - 1);
-    }
-
-    qemu_iovec_add(&io->iov, io->dma_mem, io->len);
-
-    if ((offset + bytes) & (align - 1)) {
-        tail_bytes = (offset + bytes) & (align - 1);
-
-        MACIO_DPRINTF("--- DMA unaligned tail: sector %" PRId64 ", "
-                      "discarding bytes %zu\n", sector_num, tail_bytes);
-
-        qemu_iovec_add(&io->iov, &io->tail_remainder, align - tail_bytes);
-        bytes = ROUND_UP(bytes, align);
-    }
-
-    s->io_buffer_size -= io->len;
-    s->io_buffer_index += io->len;
-
-    io->len = 0;
-
-    MACIO_DPRINTF("--- Block read transfer - sector_num: %" PRIx64 "  "
-                  "nsector: %x\n", (offset >> 9), (bytes >> 9));
-
-    s->bus->dma->aiocb = blk_aio_preadv(blk, offset, &io->iov, 0, cb, io);
-}
-
-static void pmac_dma_write(BlockBackend *blk,
-                         int64_t offset, int bytes,
-                         void (*cb)(void *opaque, int ret), void *opaque)
-{
-    DBDMA_io *io = opaque;
-    MACIOIDEState *m = io->opaque;
-    IDEState *s = idebus_active_if(&m->bus);
-    dma_addr_t dma_addr;
-    int64_t sector_num;
-    int nsector;
-    uint64_t align = BDRV_SECTOR_SIZE;
-    size_t head_bytes, tail_bytes;
-    bool unaligned_head = false, unaligned_tail = false;
-
-    qemu_iovec_destroy(&io->iov);
-    qemu_iovec_init(&io->iov, io->len / MACIO_PAGE_SIZE + 1);
-
-    sector_num = (offset >> 9);
-    nsector = (io->len >> 9);
-
-    MACIO_DPRINTF("--- DMA write transfer (0x%" HWADDR_PRIx ",0x%x): "
-                  "sector_num: %" PRId64 ", nsector: %d\n", io->addr, io->len,
-                  sector_num, nsector);
-
-    dma_addr = io->addr;
-    io->dir = DMA_DIRECTION_TO_DEVICE;
-    io->dma_len = io->len;
-    io->dma_mem = dma_memory_map(&address_space_memory, dma_addr, &io->dma_len,
-                                 io->dir);
-
-    if (offset & (align - 1)) {
-        head_bytes = offset & (align - 1);
-        sector_num = ((offset & ~(align - 1)) >> 9);
-
-        MACIO_DPRINTF("--- DMA unaligned head: pre-reading head sector %"
-                      PRId64 "\n", sector_num);
-
-        blk_pread(s->blk, (sector_num << 9), &io->head_remainder, align);
-
-        qemu_iovec_add(&io->iov, &io->head_remainder, head_bytes);
-        qemu_iovec_add(&io->iov, io->dma_mem, io->len);
-
-        bytes += offset & (align - 1);
-        offset = offset & ~(align - 1);
-
-        unaligned_head = true;
-    }
-
-    if ((offset + bytes) & (align - 1)) {
-        tail_bytes = (offset + bytes) & (align - 1);
-        sector_num = (((offset + bytes) & ~(align - 1)) >> 9);
-
-        MACIO_DPRINTF("--- DMA unaligned tail: pre-reading tail sector %"
-                      PRId64 "\n", sector_num);
-
-        blk_pread(s->blk, (sector_num << 9), &io->tail_remainder, align);
-
-        if (!unaligned_head) {
-            qemu_iovec_add(&io->iov, io->dma_mem, io->len);
-        }
-
-        qemu_iovec_add(&io->iov, &io->tail_remainder + tail_bytes,
-                       align - tail_bytes);
-
-        bytes = ROUND_UP(bytes, align);
-
-        unaligned_tail = true;
-    }
-
-    if (!unaligned_head && !unaligned_tail) {
-        qemu_iovec_add(&io->iov, io->dma_mem, io->len);
-    }
-
-    s->io_buffer_size -= io->len;
-    s->io_buffer_index += io->len;
-
-    io->len = 0;
-
-    MACIO_DPRINTF("--- Block write transfer - sector_num: %" PRIx64 "  "
-                  "nsector: %x\n", (offset >> 9), (bytes >> 9));
-
-    s->bus->dma->aiocb = blk_aio_pwritev(blk, offset, &io->iov, 0, cb, io);
-}
-
-static void pmac_dma_trim(BlockBackend *blk,
-                        int64_t offset, int bytes,
-                        void (*cb)(void *opaque, int ret), void *opaque)
-{
-    DBDMA_io *io = opaque;
-    MACIOIDEState *m = io->opaque;
-    IDEState *s = idebus_active_if(&m->bus);
-    dma_addr_t dma_addr;
-
-    qemu_iovec_destroy(&io->iov);
-    qemu_iovec_init(&io->iov, io->len / MACIO_PAGE_SIZE + 1);
-
-    dma_addr = io->addr;
-    io->dir = DMA_DIRECTION_TO_DEVICE;
-    io->dma_len = io->len;
-    io->dma_mem = dma_memory_map(&address_space_memory, dma_addr, &io->dma_len,
-                                 io->dir);
-
-    qemu_iovec_add(&io->iov, io->dma_mem, io->len);
-    s->io_buffer_size -= io->len;
-    s->io_buffer_index += io->len;
-    io->len = 0;
-
-    s->bus->dma->aiocb = ide_issue_trim(offset, &io->iov, cb, io, blk);
-}
-
 static void pmac_ide_atapi_transfer_cb(void *opaque, int ret)
 {
     DBDMA_io *io = opaque;
@@ -244,6 +63,7 @@ static void pmac_ide_atapi_transfer_cb(void *opaque, int ret)
 
     if (ret < 0) {
         MACIO_DPRINTF("DMA error: %d\n", ret);
+        qemu_sglist_destroy(&s->sg);
         ide_atapi_io_error(s, ret);
         goto done;
     }
@@ -258,6 +78,7 @@ static void pmac_ide_atapi_transfer_cb(void *opaque, int ret)
 
     if (s->io_buffer_size <= 0) {
         MACIO_DPRINTF("End of IDE transfer\n");
+        qemu_sglist_destroy(&s->sg);
         ide_atapi_cmd_ok(s);
         m->dma_active = false;
         goto done;
@@ -282,7 +103,15 @@ static void pmac_ide_atapi_transfer_cb(void *opaque, int ret)
     /* Calculate current offset */
     offset = ((int64_t)s->lba << 11) + s->io_buffer_index;
 
-    pmac_dma_read(s->blk, offset, io->len, pmac_ide_atapi_transfer_cb, io);
+    qemu_sglist_init(&s->sg, DEVICE(m), io->len / MACIO_PAGE_SIZE + 1,
+                     &address_space_memory);
+    qemu_sglist_add(&s->sg, io->addr, io->len);
+    s->io_buffer_size -= io->len;
+    s->io_buffer_index += io->len;
+    io->len = 0;
+
+    s->bus->dma->aiocb = dma_blk_read(s->blk, &s->sg, offset, 0x1,
+                                      pmac_ide_atapi_transfer_cb, io);
     return;
 
 done:
@@ -310,6 +139,7 @@ static void pmac_ide_transfer_cb(void *opaque, int ret)
 
     if (ret < 0) {
         MACIO_DPRINTF("DMA error: %d\n", ret);
+        qemu_sglist_destroy(&s->sg);
         ide_dma_error(s);
         goto done;
     }
@@ -324,6 +154,7 @@ static void pmac_ide_transfer_cb(void *opaque, int ret)
 
     if (s->io_buffer_size <= 0) {
         MACIO_DPRINTF("End of IDE transfer\n");
+        qemu_sglist_destroy(&s->sg);
         s->status = READY_STAT | SEEK_STAT;
         ide_set_irq(s->bus);
         m->dma_active = false;
@@ -338,15 +169,27 @@ static void pmac_ide_transfer_cb(void *opaque, int ret)
     /* Calculate number of sectors */
     offset = (ide_get_sector(s) << 9) + s->io_buffer_index;
 
+    qemu_sglist_init(&s->sg, DEVICE(m), io->len / MACIO_PAGE_SIZE + 1,
+                     &address_space_memory);
+    qemu_sglist_add(&s->sg, io->addr, io->len);
+    s->io_buffer_size -= io->len;
+    s->io_buffer_index += io->len;
+    io->len = 0;
+
     switch (s->dma_cmd) {
     case IDE_DMA_READ:
-        pmac_dma_read(s->blk, offset, io->len, pmac_ide_transfer_cb, io);
+        s->bus->dma->aiocb = dma_blk_read(s->blk, &s->sg, offset, 0x1,
+                                          pmac_ide_atapi_transfer_cb, io);
         break;
     case IDE_DMA_WRITE:
-        pmac_dma_write(s->blk, offset, io->len, pmac_ide_transfer_cb, io);
+        s->bus->dma->aiocb = dma_blk_write(s->blk, &s->sg, offset, 0x1,
+                                           pmac_ide_transfer_cb, io);
         break;
     case IDE_DMA_TRIM:
-        pmac_dma_trim(s->blk, offset, io->len, pmac_ide_transfer_cb, io);
+        s->bus->dma->aiocb = dma_blk_io(blk_get_aio_context(s->blk), &s->sg,
+                                        offset, 0x1, ide_issue_trim, s->blk,
+                                        pmac_ide_transfer_cb, io,
+                                        DMA_DIRECTION_TO_DEVICE);
         break;
     default:
         abort();
-- 
2.7.4