iommu/dma: Trace bounce buffer usage when mapping buffers

commit a63c357b9fd56ad5fe64616f5b22835252c6a76a upstream.

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: stable@vger.kernel.org # v5.15+
Cc: Tom Murphy <murphyt7@tcd.ie>
Cc: Lu Baolu <baolu.lu@linux.intel.com>
Cc: Saravana Kannan <saravanak@google.com>
Signed-off-by: Isaac J. Manjarres <isaacmanjarres@google.com>
Link: https://lore.kernel.org/r/20231208234141.2356157-1-isaacmanjarres@google.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 4b1a88f..e5d087b 100644 (file)
--- 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"
 
@@ -1052,6 +1053,8 @@ 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);