[Qemu-devel] [PATCH 4/7] ide: factor dma handling helpers

[Christoph Hellwig <hch@lst.de>]

The DMA I/O path is duplicated between read and write commands, and
support for the TRIM command would add another copy.  Factor the
code into common helpers using the s->is_read flag added for the
macio ATA controller, and the newly added dma_bdrv_io function.

Signed-off-by: Christoph Hellwig <hch@lst.de>

Index: qemu/hw/ide/core.c
===================================================================
--- qemu.orig/hw/ide/core.c	2010-12-10 11:17:57.328254648 +0100
+++ qemu/hw/ide/core.c	2010-12-10 11:35:23.164005731 +0100
@@ -61,7 +61,8 @@ static inline int media_is_cd(IDEState *
     return (media_present(s) && s->nb_sectors <= CD_MAX_SECTORS);
 }
 
-static void ide_dma_start(IDEState *s, BlockDriverCompletionFunc *dma_cb);
+static void ide_dma_start(IDEState *s, BlockDriverCompletionFunc *dma_cb,
+       DMAIOFunc *io_func);
 static void ide_dma_restart(IDEState *s, int is_read);
 static void ide_atapi_cmd_read_dma_cb(void *opaque, int ret);
 static int ide_handle_rw_error(IDEState *s, int error, int op);
@@ -568,7 +569,7 @@ static int dma_buf_rw(BMDMAState *bm, in
     return 1;
 }
 
-static void ide_read_dma_cb(void *opaque, int ret)
+static void ide_dma_cb(void *opaque, int ret)
 {
     BMDMAState *bm = opaque;
     IDEState *s = bmdma_active_if(bm);
@@ -576,9 +577,12 @@ static void ide_read_dma_cb(void *opaque
     int64_t sector_num;
 
     if (ret < 0) {
-        if (ide_handle_rw_error(s, -ret,
-            BM_STATUS_DMA_RETRY | BM_STATUS_RETRY_READ))
-        {
+        int op = BM_STATUS_DMA_RETRY;
+
+        if (s->is_read)
+            op |= BM_STATUS_RETRY_READ;
+
+        if (ide_handle_rw_error(s, -ret, op)) {
             return;
         }
     }
@@ -586,7 +590,7 @@ static void ide_read_dma_cb(void *opaque
     n = s->io_buffer_size >> 9;
     sector_num = ide_get_sector(s);
     if (n > 0) {
-        dma_buf_commit(s, 1);
+        dma_buf_commit(s, s->is_read);
         sector_num += n;
         ide_set_sector(s, sector_num);
         s->nsector -= n;
@@ -596,32 +600,39 @@ static void ide_read_dma_cb(void *opaque
     if (s->nsector == 0) {
         s->status = READY_STAT | SEEK_STAT;
         ide_set_irq(s->bus);
-    eot:
-        bm->status |= BM_STATUS_INT;
-        ide_dma_set_inactive(bm);
-        return;
+        goto eot;
     }
 
     /* launch next transfer */
     n = s->nsector;
-    s->io_buffer_index = 0;
+    if (s->is_read)
+        s->io_buffer_index = 0;
     s->io_buffer_size = n * 512;
-    if (dma_buf_prepare(bm, 1) == 0)
+    if (dma_buf_prepare(bm, s->is_read) == 0)
         goto eot;
+
 #ifdef DEBUG_AIO
-    printf("aio_read: sector_num=%" PRId64 " n=%d\n", sector_num, n);
+    printf("ide_dma_cb: read: %d sector_num=%" PRId64 " n=%d\n",
+           s->is_read, sector_num, n);
 #endif
-    bm->aiocb = dma_bdrv_read(s->bs, &s->sg, sector_num, ide_read_dma_cb, bm);
-    ide_dma_submit_check(s, ide_read_dma_cb, bm);
+
+    bm->aiocb = dma_bdrv_io(s->bs, &s->sg, sector_num, bm->io_func,
+                            ide_dma_cb, bm, !s->is_read);
+    ide_dma_submit_check(s, ide_dma_cb, bm);
+    return;
+
+eot:
+    bm->status |= BM_STATUS_INT;
+    ide_dma_set_inactive(bm);
 }
 
-static void ide_sector_read_dma(IDEState *s)
+static void ide_sector_dma(IDEState *s, DMAIOFunc *io_func, bool is_read)
 {
     s->status = READY_STAT | SEEK_STAT | DRQ_STAT | BUSY_STAT;
     s->io_buffer_index = 0;
     s->io_buffer_size = 0;
-    s->is_read = 1;
-    ide_dma_start(s, ide_read_dma_cb);
+    s->is_read = is_read;
+    ide_dma_start(s, ide_dma_cb, io_func);
 }
 
 static void ide_sector_write_timer_cb(void *opaque)
@@ -714,58 +725,6 @@ void ide_dma_restart_cb(void *opaque, in
     }
 }
 
-static void ide_write_dma_cb(void *opaque, int ret)
-{
-    BMDMAState *bm = opaque;
-    IDEState *s = bmdma_active_if(bm);
-    int n;
-    int64_t sector_num;
-
-    if (ret < 0) {
-        if (ide_handle_rw_error(s, -ret,  BM_STATUS_DMA_RETRY))
-            return;
-    }
-
-    n = s->io_buffer_size >> 9;
-    sector_num = ide_get_sector(s);
-    if (n > 0) {
-        dma_buf_commit(s, 0);
-        sector_num += n;
-        ide_set_sector(s, sector_num);
-        s->nsector -= n;
-    }
-
-    /* end of transfer ? */
-    if (s->nsector == 0) {
-        s->status = READY_STAT | SEEK_STAT;
-        ide_set_irq(s->bus);
-    eot:
-        bm->status |= BM_STATUS_INT;
-        ide_dma_set_inactive(bm);
-        return;
-    }
-
-    n = s->nsector;
-    s->io_buffer_size = n * 512;
-    /* launch next transfer */
-    if (dma_buf_prepare(bm, 0) == 0)
-        goto eot;
-#ifdef DEBUG_AIO
-    printf("aio_write: sector_num=%" PRId64 " n=%d\n", sector_num, n);
-#endif
-    bm->aiocb = dma_bdrv_write(s->bs, &s->sg, sector_num, ide_write_dma_cb, bm);
-    ide_dma_submit_check(s, ide_write_dma_cb, bm);
-}
-
-static void ide_sector_write_dma(IDEState *s)
-{
-    s->status = READY_STAT | SEEK_STAT | DRQ_STAT | BUSY_STAT;
-    s->io_buffer_index = 0;
-    s->io_buffer_size = 0;
-    s->is_read = 0;
-    ide_dma_start(s, ide_write_dma_cb);
-}
-
 void ide_atapi_cmd_ok(IDEState *s)
 {
     s->error = 0;
@@ -1003,7 +962,7 @@ static void ide_atapi_cmd_reply(IDEState
 
     if (s->atapi_dma) {
     	s->status = READY_STAT | SEEK_STAT | DRQ_STAT;
-	ide_dma_start(s, ide_atapi_cmd_read_dma_cb);
+	ide_dma_start(s, ide_atapi_cmd_read_dma_cb, NULL);
     } else {
     	s->status = READY_STAT | SEEK_STAT;
     	ide_atapi_cmd_reply_end(s);
@@ -1111,7 +1070,7 @@ static void ide_atapi_cmd_read_dma(IDESt
 
     /* XXX: check if BUSY_STAT should be set */
     s->status = READY_STAT | SEEK_STAT | DRQ_STAT | BUSY_STAT;
-    ide_dma_start(s, ide_atapi_cmd_read_dma_cb);
+    ide_dma_start(s, ide_atapi_cmd_read_dma_cb, NULL);
 }
 
 static void ide_atapi_cmd_read(IDEState *s, int lba, int nb_sectors,
@@ -1968,7 +1927,7 @@ void ide_ioport_write(void *opaque, uint
             if (!s->bs)
                 goto abort_cmd;
 	    ide_cmd_lba48_transform(s, lba48);
-            ide_sector_read_dma(s);
+            ide_sector_dma(s, bdrv_aio_readv, 1);
             break;
 	case WIN_WRITEDMA_EXT:
 	    lba48 = 1;
@@ -1977,7 +1936,7 @@ void ide_ioport_write(void *opaque, uint
             if (!s->bs)
                 goto abort_cmd;
 	    ide_cmd_lba48_transform(s, lba48);
-            ide_sector_write_dma(s);
+            ide_sector_dma(s, bdrv_aio_writev, 0);
             s->media_changed = 1;
             break;
         case WIN_READ_NATIVE_MAX_EXT:
@@ -2912,13 +2871,15 @@ const VMStateDescription vmstate_ide_bus
 /***********************************************************/
 /* PCI IDE definitions */
 
-static void ide_dma_start(IDEState *s, BlockDriverCompletionFunc *dma_cb)
+static void ide_dma_start(IDEState *s, BlockDriverCompletionFunc *dma_cb,
+       DMAIOFunc *io_func)
 {
     BMDMAState *bm = s->bus->bmdma;
     if(!bm)
         return;
     bm->unit = s->unit;
     bm->dma_cb = dma_cb;
+    bm->io_func = io_func;
     bm->cur_prd_last = 0;
     bm->cur_prd_addr = 0;
     bm->cur_prd_len = 0;
@@ -2936,15 +2897,11 @@ static void ide_dma_restart(IDEState *s,
     s->io_buffer_index = 0;
     s->io_buffer_size = 0;
     s->nsector = bm->nsector;
+    s->is_read = is_read;
     bm->cur_addr = bm->addr;
 
-    if (is_read) {
-        bm->dma_cb = ide_read_dma_cb;
-    } else {
-        bm->dma_cb = ide_write_dma_cb;
-    }
-
-    ide_dma_start(s, bm->dma_cb);
+    bm->dma_cb = ide_dma_cb;
+    ide_dma_start(s, bm->dma_cb, bm->io_func);
 }
 
 void ide_dma_cancel(BMDMAState *bm)
Index: qemu/hw/ide/internal.h
===================================================================
--- qemu.orig/hw/ide/internal.h	2010-12-10 11:17:57.348254927 +0100
+++ qemu/hw/ide/internal.h	2010-12-10 11:33:41.444006150 +0100
@@ -433,7 +433,6 @@ struct IDEState {
     uint32_t mdata_size;
     uint8_t *mdata_storage;
     int media_changed;
-    /* for pmac */
     int is_read;
     /* SMART */
     uint8_t smart_enabled;
@@ -493,6 +492,7 @@ struct BMDMAState {
     uint8_t unit;
     BlockDriverCompletionFunc *dma_cb;
     BlockDriverAIOCB *aiocb;
+    DMAIOFunc *io_func;
     struct iovec iov;
     QEMUIOVector qiov;
     int64_t sector_num;
Index: qemu/hw/ide/macio.c
===================================================================
--- qemu.orig/hw/ide/macio.c	2010-12-10 11:17:57.357254927 +0100
+++ qemu/hw/ide/macio.c	2010-12-10 11:19:00.936260584 +0100
@@ -146,12 +146,8 @@ static void pmac_ide_transfer_cb(void *o
     io->addr += io->len;
     io->len = 0;
 
-    if (s->is_read)
-        m->aiocb = dma_bdrv_read(s->bs, &s->sg, sector_num,
-		                 pmac_ide_transfer_cb, io);
-    else
-        m->aiocb = dma_bdrv_write(s->bs, &s->sg, sector_num,
-		                  pmac_ide_transfer_cb, io);
+    m->aiocb = dma_bdrv_io(s->bs, &s->sg, sector_num, s->io_func,
+		           pmac_ide_transfer_cb, io, !s->is_read);
     if (!m->aiocb)
         pmac_ide_transfer_cb(io, -1);
 }