2023-12-08 23:42:09

by Isaac J. Manjarres

Subject: [PATCH v1] iommu/dma: Trace bounce buffer usage when mapping buffers

When commit 82612d66d51d ("iommu: Allow the dma-iommu api to
use bounce buffers") was introduced, it did not add the logic
for tracing the bounce buffer usage from iommu_dma_map_page().

All of the users of swiotlb_tbl_map_single() trace their bounce
buffer usage, except iommu_dma_map_page(). This makes it difficult
to track SWIOTLB usage from that function. Thus, trace bounce buffer
usage from iommu_dma_map_page().

Fixes: 82612d66d51d ("iommu: Allow the dma-iommu api to use bounce buffers")
Cc: [email protected] # v5.15+
Cc: Tom Murphy <[email protected]>
Cc: Lu Baolu <[email protected]>
Cc: Saravana Kannan <[email protected]>
Signed-off-by: Isaac J. Manjarres <[email protected]>
---
drivers/iommu/dma-iommu.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 85163a83df2f..037fcf826407 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -29,6 +29,7 @@
#include <linux/spinlock.h>
#include <linux/swiotlb.h>
#include <linux/vmalloc.h>
+#include <trace/events/swiotlb.h>

#include "dma-iommu.h"

@@ -1156,6 +1157,8 @@ static dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page,
return DMA_MAPPING_ERROR;
}

+ trace_swiotlb_bounced(dev, phys, size);
+
aligned_size = iova_align(iovad, size);
phys = swiotlb_tbl_map_single(dev, phys, size, aligned_size,
iova_mask(iovad), dir, attrs);
--
2.43.0.472.g3155946c3a-goog

2023-12-15 08:05:06

by Joerg Roedel

Subject: Re: [PATCH v1] iommu/dma: Trace bounce buffer usage when mapping buffers

On Fri, Dec 08, 2023 at 03:41:40PM -0800, Isaac J. Manjarres wrote:
> drivers/iommu/dma-iommu.c | 3 +++
> 1 file changed, 3 insertions(+)

Applied, thanks.