[Qemu-devel] [PATCH] macio: handle non-block ATAPI DMA transfers

[Qemu-devel] [PATCH] macio: handle non-block ATAPI DMA transfers

[Mark Cave-Ayland]

Currently the macio DMA routines assume that all DMA requests are for read/write
block transfers. This is not always the case for ATAPI, for example when
requesting a TOC where the response is generated directly in the IDE buffer.

Detect these non-block ATAPI DMA transfers (where no lba is specified in the
command) and copy the results directly into RAM as indicated by the DBDMA
descriptor. This fixes CDROM access under MorphOS.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
---
 hw/ide/macio.c |   21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/hw/ide/macio.c b/hw/ide/macio.c
index 1c20616..af57168 100644
--- a/hw/ide/macio.c
+++ b/hw/ide/macio.c
@@ -337,6 +337,27 @@ static void pmac_ide_transfer(DBDMA_io *io)
 
     s->io_buffer_size = 0;
     if (s->drive_kind == IDE_CD) {
+
+        /* Handle non-block ATAPI DMA transfers */
+        if (s->lba == -1) {
+            s->io_buffer_size = MIN(io->len, s->packet_transfer_size);
+            bdrv_acct_start(s->bs, &s->acct, s->io_buffer_size,
+                            BDRV_ACCT_READ);
+            MACIO_DPRINTF("non-block ATAPI DMA transfer size: %d\n",
+                          s->io_buffer_size);
+
+            /* Copy ATAPI buffer directly to RAM and finish */
+            cpu_physical_memory_write(io->addr, s->io_buffer,
+                                      s->io_buffer_size);
+            ide_atapi_cmd_ok(s);
+            m->dma_active = false;
+
+            MACIO_DPRINTF("end of non-block ATAPI DMA transfer\n");
+            bdrv_acct_done(s->bs, &s->acct);
+            io->dma_end(io);
+            return;
+        }
+
         bdrv_acct_start(s->bs, &s->acct, io->len, BDRV_ACCT_READ);
         pmac_ide_atapi_transfer_cb(io, 0);
         return;
-- 
1.7.10.4

Re: [Qemu-devel] [PATCH] macio: handle non-block ATAPI DMA transfers

[Alexander Graf]

On 18.05.14 14:20, Mark Cave-Ayland wrote:
> Currently the macio DMA routines assume that all DMA requests are for read/write
> block transfers. This is not always the case for ATAPI, for example when
> requesting a TOC where the response is generated directly in the IDE buffer.
>
> Detect these non-block ATAPI DMA transfers (where no lba is specified in the
> command) and copy the results directly into RAM as indicated by the DBDMA
> descriptor. This fixes CDROM access under MorphOS.
>
> Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>

Thanks, applied to ppc-next.


Alex