diff mbox

[1/2] dma-helpers: explicitly pass alignment into dma-helpers

Message ID 1476031419-6805-2-git-send-email-mark.cave-ayland@ilande.co.uk (mailing list archive)
State New, archived
Headers show

Commit Message

Mark Cave-Ayland Oct. 9, 2016, 4:43 p.m. UTC
The hard-coded default alignment is BDRV_SECTOR_SIZE, however this is not
necessarily the case for all platforms. Use this as the default alignment for
all current callers.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
---
 dma-helpers.c        |   20 +++++++++++---------
 hw/block/nvme.c      |    6 ++++--
 hw/ide/ahci.c        |    2 ++
 hw/ide/core.c        |    6 +++---
 hw/scsi/scsi-disk.c  |    2 ++
 include/sysemu/dma.h |    6 +++---
 6 files changed, 25 insertions(+), 17 deletions(-)

Comments

Eric Blake Oct. 10, 2016, 4:34 p.m. UTC | #1
On 10/09/2016 11:43 AM, Mark Cave-Ayland wrote:
> The hard-coded default alignment is BDRV_SECTOR_SIZE, however this is not
> necessarily the case for all platforms. Use this as the default alignment for
> all current callers.
> 
> Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
> ---

> @@ -160,8 +161,8 @@ static void dma_blk_cb(void *opaque, int ret)
>          return;
>      }
>  
> -    if (dbs->iov.size & ~BDRV_SECTOR_MASK) {
> -        qemu_iovec_discard_back(&dbs->iov, dbs->iov.size & ~BDRV_SECTOR_MASK);
> +    if (dbs->iov.size & (dbs->align - 1)) {
> +        qemu_iovec_discard_back(&dbs->iov, dbs->iov.size & (dbs->align - 1));

Would it be any smarter to use osdep.h's QEMU_IS_ALIGNED(dbs->iov.size,
dbs->align) and QEMU_ALIGN_DOWN(dbs->iov.size, dbs->align)?
Semantically it is the same, but the macros make it obvious what the
bit-twiddling is doing.

Unless you think that needs a tweak,
Reviewed-by: Eric Blake <eblake@redhat.com>
Mark Cave-Ayland Oct. 10, 2016, 7:23 p.m. UTC | #2
On 10/10/16 17:34, Eric Blake wrote:

> On 10/09/2016 11:43 AM, Mark Cave-Ayland wrote:
>> The hard-coded default alignment is BDRV_SECTOR_SIZE, however this is not
>> necessarily the case for all platforms. Use this as the default alignment for
>> all current callers.
>>
>> Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
>> ---
> 
>> @@ -160,8 +161,8 @@ static void dma_blk_cb(void *opaque, int ret)
>>          return;
>>      }
>>  
>> -    if (dbs->iov.size & ~BDRV_SECTOR_MASK) {
>> -        qemu_iovec_discard_back(&dbs->iov, dbs->iov.size & ~BDRV_SECTOR_MASK);
>> +    if (dbs->iov.size & (dbs->align - 1)) {
>> +        qemu_iovec_discard_back(&dbs->iov, dbs->iov.size & (dbs->align - 1));
> 
> Would it be any smarter to use osdep.h's QEMU_IS_ALIGNED(dbs->iov.size,
> dbs->align) and QEMU_ALIGN_DOWN(dbs->iov.size, dbs->align)?
> Semantically it is the same, but the macros make it obvious what the
> bit-twiddling is doing.
> 
> Unless you think that needs a tweak,
> Reviewed-by: Eric Blake <eblake@redhat.com>

I can't say I feel too strongly about it since there are plenty of other
examples of this style in the codebase, so I'm happy to go with whatever
John/Paolo are most happy with.


ATB,

Mark.
John Snow Oct. 11, 2016, 3:47 p.m. UTC | #3
On 10/10/2016 03:23 PM, Mark Cave-Ayland wrote:
> On 10/10/16 17:34, Eric Blake wrote:
>
>> On 10/09/2016 11:43 AM, Mark Cave-Ayland wrote:
>>> The hard-coded default alignment is BDRV_SECTOR_SIZE, however this is not
>>> necessarily the case for all platforms. Use this as the default alignment for
>>> all current callers.
>>>
>>> Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
>>> ---
>>
>>> @@ -160,8 +161,8 @@ static void dma_blk_cb(void *opaque, int ret)
>>>          return;
>>>      }
>>>
>>> -    if (dbs->iov.size & ~BDRV_SECTOR_MASK) {
>>> -        qemu_iovec_discard_back(&dbs->iov, dbs->iov.size & ~BDRV_SECTOR_MASK);
>>> +    if (dbs->iov.size & (dbs->align - 1)) {
>>> +        qemu_iovec_discard_back(&dbs->iov, dbs->iov.size & (dbs->align - 1));
>>
>> Would it be any smarter to use osdep.h's QEMU_IS_ALIGNED(dbs->iov.size,
>> dbs->align) and QEMU_ALIGN_DOWN(dbs->iov.size, dbs->align)?
>> Semantically it is the same, but the macros make it obvious what the
>> bit-twiddling is doing.
>>
>> Unless you think that needs a tweak,
>> Reviewed-by: Eric Blake <eblake@redhat.com>
>
> I can't say I feel too strongly about it since there are plenty of other
> examples of this style in the codebase, so I'm happy to go with whatever
> John/Paolo are most happy with.
>
>
> ATB,
>
> Mark.
>

I can't pretend I am consistent, but when in doubt use the macro. Not 
worth a respin IMO, but I think this falls out of my jurisdiction :)

Acked-by: John Snow <jsnow@redhat.com>
Kevin Wolf Oct. 12, 2016, 10:22 a.m. UTC | #4
Am 11.10.2016 um 17:47 hat John Snow geschrieben:
> On 10/10/2016 03:23 PM, Mark Cave-Ayland wrote:
> >On 10/10/16 17:34, Eric Blake wrote:
> >
> >>On 10/09/2016 11:43 AM, Mark Cave-Ayland wrote:
> >>>The hard-coded default alignment is BDRV_SECTOR_SIZE, however this is not
> >>>necessarily the case for all platforms. Use this as the default alignment for
> >>>all current callers.
> >>>
> >>>Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
> >>>---
> >>
> >>>@@ -160,8 +161,8 @@ static void dma_blk_cb(void *opaque, int ret)
> >>>         return;
> >>>     }
> >>>
> >>>-    if (dbs->iov.size & ~BDRV_SECTOR_MASK) {
> >>>-        qemu_iovec_discard_back(&dbs->iov, dbs->iov.size & ~BDRV_SECTOR_MASK);
> >>>+    if (dbs->iov.size & (dbs->align - 1)) {
> >>>+        qemu_iovec_discard_back(&dbs->iov, dbs->iov.size & (dbs->align - 1));
> >>
> >>Would it be any smarter to use osdep.h's QEMU_IS_ALIGNED(dbs->iov.size,
> >>dbs->align) and QEMU_ALIGN_DOWN(dbs->iov.size, dbs->align)?
> >>Semantically it is the same, but the macros make it obvious what the
> >>bit-twiddling is doing.
> >>
> >>Unless you think that needs a tweak,
> >>Reviewed-by: Eric Blake <eblake@redhat.com>
> >
> >I can't say I feel too strongly about it since there are plenty of other
> >examples of this style in the codebase, so I'm happy to go with whatever
> >John/Paolo are most happy with.
> >
> >
> >ATB,
> >
> >Mark.
> >
> 
> I can't pretend I am consistent, but when in doubt use the macro.
> Not worth a respin IMO, but I think this falls out of my
> jurisdiction :)
> 
> Acked-by: John Snow <jsnow@redhat.com>

dma-helpers.c is officially unmaintained, and as the other patch is
clearly IDE, I think the series should go through your tree.

Kevin
John Snow Oct. 12, 2016, 4:04 p.m. UTC | #5
On 10/12/2016 06:22 AM, Kevin Wolf wrote:
> Am 11.10.2016 um 17:47 hat John Snow geschrieben:
>> On 10/10/2016 03:23 PM, Mark Cave-Ayland wrote:
>>> On 10/10/16 17:34, Eric Blake wrote:
>>>
>>>> On 10/09/2016 11:43 AM, Mark Cave-Ayland wrote:
>>>>> The hard-coded default alignment is BDRV_SECTOR_SIZE, however this is not
>>>>> necessarily the case for all platforms. Use this as the default alignment for
>>>>> all current callers.
>>>>>
>>>>> Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
>>>>> ---
>>>>
>>>>> @@ -160,8 +161,8 @@ static void dma_blk_cb(void *opaque, int ret)
>>>>>         return;
>>>>>     }
>>>>>
>>>>> -    if (dbs->iov.size & ~BDRV_SECTOR_MASK) {
>>>>> -        qemu_iovec_discard_back(&dbs->iov, dbs->iov.size & ~BDRV_SECTOR_MASK);
>>>>> +    if (dbs->iov.size & (dbs->align - 1)) {
>>>>> +        qemu_iovec_discard_back(&dbs->iov, dbs->iov.size & (dbs->align - 1));
>>>>
>>>> Would it be any smarter to use osdep.h's QEMU_IS_ALIGNED(dbs->iov.size,
>>>> dbs->align) and QEMU_ALIGN_DOWN(dbs->iov.size, dbs->align)?
>>>> Semantically it is the same, but the macros make it obvious what the
>>>> bit-twiddling is doing.
>>>>
>>>> Unless you think that needs a tweak,
>>>> Reviewed-by: Eric Blake <eblake@redhat.com>
>>>
>>> I can't say I feel too strongly about it since there are plenty of other
>>> examples of this style in the codebase, so I'm happy to go with whatever
>>> John/Paolo are most happy with.
>>>
>>>
>>> ATB,
>>>
>>> Mark.
>>>
>>
>> I can't pretend I am consistent, but when in doubt use the macro.
>> Not worth a respin IMO, but I think this falls out of my
>> jurisdiction :)
>>
>> Acked-by: John Snow <jsnow@redhat.com>
>
> dma-helpers.c is officially unmaintained, and as the other patch is
> clearly IDE, I think the series should go through your tree.
>
> Kevin
>

Oh! I was under the impression that Paolo had the dma-helpers. My 
mistake. I will test and stage this.

--js
diff mbox

Patch

diff --git a/dma-helpers.c b/dma-helpers.c
index 9defc10..3caa2ab 100644
--- a/dma-helpers.c
+++ b/dma-helpers.c
@@ -73,6 +73,7 @@  typedef struct {
     AioContext *ctx;
     BlockAIOCB *acb;
     QEMUSGList *sg;
+    uint32_t align;
     uint64_t offset;
     DMADirection dir;
     int sg_cur_index;
@@ -160,8 +161,8 @@  static void dma_blk_cb(void *opaque, int ret)
         return;
     }
 
-    if (dbs->iov.size & ~BDRV_SECTOR_MASK) {
-        qemu_iovec_discard_back(&dbs->iov, dbs->iov.size & ~BDRV_SECTOR_MASK);
+    if (dbs->iov.size & (dbs->align - 1)) {
+        qemu_iovec_discard_back(&dbs->iov, dbs->iov.size & (dbs->align - 1));
     }
 
     dbs->acb = dbs->io_func(dbs->offset, &dbs->iov,
@@ -199,7 +200,7 @@  static const AIOCBInfo dma_aiocb_info = {
 };
 
 BlockAIOCB *dma_blk_io(AioContext *ctx,
-    QEMUSGList *sg, uint64_t offset,
+    QEMUSGList *sg, uint64_t offset, uint32_t align,
     DMAIOFunc *io_func, void *io_func_opaque,
     BlockCompletionFunc *cb,
     void *opaque, DMADirection dir)
@@ -212,6 +213,7 @@  BlockAIOCB *dma_blk_io(AioContext *ctx,
     dbs->sg = sg;
     dbs->ctx = ctx;
     dbs->offset = offset;
+    dbs->align = align;
     dbs->sg_cur_index = 0;
     dbs->sg_cur_byte = 0;
     dbs->dir = dir;
@@ -234,11 +236,11 @@  BlockAIOCB *dma_blk_read_io_func(int64_t offset, QEMUIOVector *iov,
 }
 
 BlockAIOCB *dma_blk_read(BlockBackend *blk,
-                         QEMUSGList *sg, uint64_t offset,
+                         QEMUSGList *sg, uint64_t offset, uint32_t align,
                          void (*cb)(void *opaque, int ret), void *opaque)
 {
-    return dma_blk_io(blk_get_aio_context(blk),
-                      sg, offset, dma_blk_read_io_func, blk, cb, opaque,
+    return dma_blk_io(blk_get_aio_context(blk), sg, offset, align,
+                      dma_blk_read_io_func, blk, cb, opaque,
                       DMA_DIRECTION_FROM_DEVICE);
 }
 
@@ -252,11 +254,11 @@  BlockAIOCB *dma_blk_write_io_func(int64_t offset, QEMUIOVector *iov,
 }
 
 BlockAIOCB *dma_blk_write(BlockBackend *blk,
-                          QEMUSGList *sg, uint64_t offset,
+                          QEMUSGList *sg, uint64_t offset, uint32_t align,
                           void (*cb)(void *opaque, int ret), void *opaque)
 {
-    return dma_blk_io(blk_get_aio_context(blk),
-                      sg, offset, dma_blk_write_io_func, blk, cb, opaque,
+    return dma_blk_io(blk_get_aio_context(blk), sg, offset, align,
+                      dma_blk_write_io_func, blk, cb, opaque,
                       DMA_DIRECTION_TO_DEVICE);
 }
 
diff --git a/hw/block/nvme.c b/hw/block/nvme.c
index cef3bb4..b380142 100644
--- a/hw/block/nvme.c
+++ b/hw/block/nvme.c
@@ -258,8 +258,10 @@  static uint16_t nvme_rw(NvmeCtrl *n, NvmeNamespace *ns, NvmeCmd *cmd,
     req->has_sg = true;
     dma_acct_start(n->conf.blk, &req->acct, &req->qsg, acct);
     req->aiocb = is_write ?
-        dma_blk_write(n->conf.blk, &req->qsg, data_offset, nvme_rw_cb, req) :
-        dma_blk_read(n->conf.blk, &req->qsg, data_offset, nvme_rw_cb, req);
+        dma_blk_write(n->conf.blk, &req->qsg, data_offset, BDRV_SECTOR_SIZE,
+                      nvme_rw_cb, req) :
+        dma_blk_read(n->conf.blk, &req->qsg, data_offset, BDRV_SECTOR_SIZE,
+                     nvme_rw_cb, req);
 
     return NVME_NO_COMPLETE;
 }
diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c
index 63ead21..3c19bda 100644
--- a/hw/ide/ahci.c
+++ b/hw/ide/ahci.c
@@ -1009,6 +1009,7 @@  static void execute_ncq_command(NCQTransferState *ncq_tfs)
                        &ncq_tfs->sglist, BLOCK_ACCT_READ);
         ncq_tfs->aiocb = dma_blk_read(ide_state->blk, &ncq_tfs->sglist,
                                       ncq_tfs->lba << BDRV_SECTOR_BITS,
+                                      BDRV_SECTOR_SIZE,
                                       ncq_cb, ncq_tfs);
         break;
     case WRITE_FPDMA_QUEUED:
@@ -1022,6 +1023,7 @@  static void execute_ncq_command(NCQTransferState *ncq_tfs)
                        &ncq_tfs->sglist, BLOCK_ACCT_WRITE);
         ncq_tfs->aiocb = dma_blk_write(ide_state->blk, &ncq_tfs->sglist,
                                        ncq_tfs->lba << BDRV_SECTOR_BITS,
+                                       BDRV_SECTOR_SIZE,
                                        ncq_cb, ncq_tfs);
         break;
     default:
diff --git a/hw/ide/core.c b/hw/ide/core.c
index 7291677..43709e5 100644
--- a/hw/ide/core.c
+++ b/hw/ide/core.c
@@ -882,15 +882,15 @@  static void ide_dma_cb(void *opaque, int ret)
     switch (s->dma_cmd) {
     case IDE_DMA_READ:
         s->bus->dma->aiocb = dma_blk_read(s->blk, &s->sg, offset,
-                                          ide_dma_cb, s);
+                                          BDRV_SECTOR_SIZE, ide_dma_cb, s);
         break;
     case IDE_DMA_WRITE:
         s->bus->dma->aiocb = dma_blk_write(s->blk, &s->sg, offset,
-                                           ide_dma_cb, s);
+                                           BDRV_SECTOR_SIZE, ide_dma_cb, s);
         break;
     case IDE_DMA_TRIM:
         s->bus->dma->aiocb = dma_blk_io(blk_get_aio_context(s->blk),
-                                        &s->sg, offset,
+                                        &s->sg, offset, BDRV_SECTOR_SIZE,
                                         ide_issue_trim, s->blk, ide_dma_cb, s,
                                         DMA_DIRECTION_TO_DEVICE);
         break;
diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c
index 88beaf4..a963191 100644
--- a/hw/scsi/scsi-disk.c
+++ b/hw/scsi/scsi-disk.c
@@ -341,6 +341,7 @@  static void scsi_do_read(SCSIDiskReq *r, int ret)
         r->req.resid -= r->req.sg->size;
         r->req.aiocb = dma_blk_io(blk_get_aio_context(s->qdev.conf.blk),
                                   r->req.sg, r->sector << BDRV_SECTOR_BITS,
+                                  BDRV_SECTOR_SIZE,
                                   sdc->dma_readv, r, scsi_dma_complete, r,
                                   DMA_DIRECTION_FROM_DEVICE);
     } else {
@@ -539,6 +540,7 @@  static void scsi_write_data(SCSIRequest *req)
         r->req.resid -= r->req.sg->size;
         r->req.aiocb = dma_blk_io(blk_get_aio_context(s->qdev.conf.blk),
                                   r->req.sg, r->sector << BDRV_SECTOR_BITS,
+                                  BDRV_SECTOR_SIZE,
                                   sdc->dma_writev, r, scsi_dma_complete, r,
                                   DMA_DIRECTION_TO_DEVICE);
     } else {
diff --git a/include/sysemu/dma.h b/include/sysemu/dma.h
index 34c8eaf..c228c66 100644
--- a/include/sysemu/dma.h
+++ b/include/sysemu/dma.h
@@ -199,14 +199,14 @@  typedef BlockAIOCB *DMAIOFunc(int64_t offset, QEMUIOVector *iov,
                               void *opaque);
 
 BlockAIOCB *dma_blk_io(AioContext *ctx,
-                       QEMUSGList *sg, uint64_t offset,
+                       QEMUSGList *sg, uint64_t offset, uint32_t align,
                        DMAIOFunc *io_func, void *io_func_opaque,
                        BlockCompletionFunc *cb, void *opaque, DMADirection dir);
 BlockAIOCB *dma_blk_read(BlockBackend *blk,
-                         QEMUSGList *sg, uint64_t offset,
+                         QEMUSGList *sg, uint64_t offset, uint32_t align,
                          BlockCompletionFunc *cb, void *opaque);
 BlockAIOCB *dma_blk_write(BlockBackend *blk,
-                          QEMUSGList *sg, uint64_t offset,
+                          QEMUSGList *sg, uint64_t offset, uint32_t align,
                           BlockCompletionFunc *cb, void *opaque);
 uint64_t dma_buf_read(uint8_t *ptr, int32_t len, QEMUSGList *sg);
 uint64_t dma_buf_write(uint8_t *ptr, int32_t len, QEMUSGList *sg);