diff mbox series

[v10,3/4] block: add a helper function to merge the segments

Message ID 1566995743-5614-4-git-send-email-yoshihiro.shimoda.uh@renesas.com (mailing list archive)
State New, archived
Headers show
Series treewide: improve R-Car SDHI performance | expand

Commit Message

Yoshihiro Shimoda Aug. 28, 2019, 12:35 p.m. UTC 
This patch adds a helper function whether a queue can merge
the segments by the DMA MAP layer (e.g. via IOMMU).

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au
---
 block/blk-settings.c   | 23 +++++++++++++++++++++++
 include/linux/blkdev.h |  2 ++
 2 files changed, 25 insertions(+)

Comments

Jens Axboe Sept. 2, 2019, 9:47 p.m. UTC | #1 
On 8/28/19 6:35 AM, Yoshihiro Shimoda wrote:
> This patch adds a helper function whether a queue can merge
> the segments by the DMA MAP layer (e.g. via IOMMU).

Reviewed-by: Jens Axboe <axboe@kernel.dk>
Yoshihiro Shimoda Sept. 3, 2019, 4:59 a.m. UTC | #2 
Hi Christoph,

Now this patch series got {Ack,Review}ed-by from each maintainer.
https://patchwork.kernel.org/project/linux-renesas-soc/list/?series=166501

So, would you pick this up through the dma-mapping tree as you said before?

> From: Jens Axboe, Sent: Tuesday, September 3, 2019 6:47 AM
> 
> On 8/28/19 6:35 AM, Yoshihiro Shimoda wrote:
> > This patch adds a helper function whether a queue can merge
> > the segments by the DMA MAP layer (e.g. via IOMMU).
> 
> Reviewed-by: Jens Axboe <axboe@kernel.dk>

Jens, thank you for your review!

Best regards,
Yoshihiro Shimoda
Christoph Hellwig Sept. 3, 2019, 6:33 a.m. UTC | #3 
On Tue, Sep 03, 2019 at 04:59:59AM +0000, Yoshihiro Shimoda wrote:
> Hi Christoph,
> 
> Now this patch series got {Ack,Review}ed-by from each maintainer.
> https://patchwork.kernel.org/project/linux-renesas-soc/list/?series=166501
> 
> So, would you pick this up through the dma-mapping tree as you said before?

I've applied it to the dma-mapping tree for 5.4 now, thanks a lot!
Yoshihiro Shimoda Sept. 3, 2019, 6:42 a.m. UTC | #4 
Hi Christoph,

> > Now this patch series got {Ack,Review}ed-by from each maintainer.
> > https://patchwork.kernel.org/project/linux-renesas-soc/list/?series=166501
> >
> > So, would you pick this up through the dma-mapping tree as you said before?
> 
> I've applied it to the dma-mapping tree for 5.4 now, thanks a lot!

Thank you very much for your support!

Best regards,
Yoshihiro Shimoda
diff mbox series

Patch

diff --git a/block/blk-settings.c b/block/blk-settings.c
index 2c18312..c3632fc 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -12,6 +12,7 @@ 
 #include <linux/lcm.h>
 #include <linux/jiffies.h>
 #include <linux/gfp.h>
+#include <linux/dma-mapping.h>
 
 #include "blk.h"
 #include "blk-wbt.h"
@@ -832,6 +833,28 @@  void blk_queue_write_cache(struct request_queue *q, bool wc, bool fua)
 }
 EXPORT_SYMBOL_GPL(blk_queue_write_cache);
 
+/**
+ * blk_queue_can_use_dma_map_merging - configure queue for merging segments.
+ * @q:		the request queue for the device
+ * @dev:	the device pointer for dma
+ *
+ * Tell the block layer about merging the segments by dma map of @q.
+ */
+bool blk_queue_can_use_dma_map_merging(struct request_queue *q,
+				       struct device *dev)
+{
+	unsigned long boundary = dma_get_merge_boundary(dev);
+
+	if (!boundary)
+		return false;
+
+	/* No need to update max_segment_size. see blk_queue_virt_boundary() */
+	blk_queue_virt_boundary(q, boundary);
+
+	return true;
+}
+EXPORT_SYMBOL_GPL(blk_queue_can_use_dma_map_merging);
+
 static int __init blk_settings_init(void)
 {
 	blk_max_low_pfn = max_low_pfn - 1;
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 1ac7901..d62d6e2 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1086,6 +1086,8 @@  extern void blk_queue_dma_alignment(struct request_queue *, int);
 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
 extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
 extern void blk_queue_write_cache(struct request_queue *q, bool enabled, bool fua);
+extern bool blk_queue_can_use_dma_map_merging(struct request_queue *q,
+					      struct device *dev);
 
 /*
  * Number of physical segments as sent to the device.