IOMMU map/unmap traces become hard to decode i.e., it becomes hard
to associate the map/unmap events with the particular device from
the iova/paddr/size parameters alone when there are multiple
devices attached. So it is useful to add the device name to iommu
trace events which can be used to filter out map/unmap traces for
a particular device when we are debugging iommu faults such as
context faults where we are interested with the map/unmap traces
for a specific device.

Before:
  map: IOMMU: iova=0x0000000ffff36000 paddr=0x00000001164d8000 size=4096
  unmap: IOMMU: iova=0x0000000ffff36000 size=4096 unmapped_size=4096

After:
  map: IOMMU: dev=1d84000.ufshc iova=0x0000000fffa88000 
paddr=0x00000001063db000 size=4096
  unmap: IOMMU: dev=1d84000.ufshc iova=0x0000000fffa88000 size=4096 
unmapped_size=4096

Signed-off-by: Sai Prakash Ranjan <saiprakash.ran...@codeaurora.org>
---
 drivers/iommu/iommu.c        |  8 +++++---
 include/linux/iommu.h        |  1 +
 include/trace/events/iommu.h | 20 ++++++++++++--------
 3 files changed, 18 insertions(+), 11 deletions(-)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index d0b0a15dba84..37081b745f38 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1947,8 +1947,10 @@ static int __iommu_attach_device(struct iommu_domain 
*domain,
                return -ENODEV;
 
        ret = domain->ops->attach_dev(domain, dev);
-       if (!ret)
+       if (!ret) {
                trace_attach_device_to_domain(dev);
+               strscpy(domain->dev_name, dev_name(dev), 
sizeof(domain->dev_name));
+       }
        return ret;
 }
 
@@ -2440,7 +2442,7 @@ static int __iommu_map(struct iommu_domain *domain, 
unsigned long iova,
        if (ret)
                iommu_unmap(domain, orig_iova, orig_size - size);
        else
-               trace_map(orig_iova, orig_paddr, orig_size);
+               trace_map(orig_iova, orig_paddr, orig_size, domain->dev_name);
 
        return ret;
 }
@@ -2523,7 +2525,7 @@ static size_t __iommu_unmap(struct iommu_domain *domain,
                unmapped += unmapped_page;
        }
 
-       trace_unmap(orig_iova, size, unmapped);
+       trace_unmap(orig_iova, size, unmapped, domain->dev_name);
        return unmapped;
 }
 
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 5e7fe519430a..6064187d9bb6 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -87,6 +87,7 @@ struct iommu_domain {
        void *handler_token;
        struct iommu_domain_geometry geometry;
        void *iova_cookie;
+       char dev_name[32];
 };
 
 enum iommu_cap {
diff --git a/include/trace/events/iommu.h b/include/trace/events/iommu.h
index 72b4582322ff..44e48fb8b677 100644
--- a/include/trace/events/iommu.h
+++ b/include/trace/events/iommu.h
@@ -85,47 +85,51 @@ DEFINE_EVENT(iommu_device_event, detach_device_from_domain,
 
 TRACE_EVENT(map,
 
-       TP_PROTO(unsigned long iova, phys_addr_t paddr, size_t size),
+       TP_PROTO(unsigned long iova, phys_addr_t paddr, size_t size, const char 
*dev_name),
 
-       TP_ARGS(iova, paddr, size),
+       TP_ARGS(iova, paddr, size, dev_name),
 
        TP_STRUCT__entry(
                __field(u64, iova)
                __field(u64, paddr)
                __field(size_t, size)
+               __string(dev_name, dev_name)
        ),
 
        TP_fast_assign(
                __entry->iova = iova;
                __entry->paddr = paddr;
                __entry->size = size;
+               __assign_str(dev_name, dev_name);
        ),
 
-       TP_printk("IOMMU: iova=0x%016llx paddr=0x%016llx size=%zu",
-                       __entry->iova, __entry->paddr, __entry->size
+       TP_printk("IOMMU: dev=%s iova=0x%016llx paddr=0x%016llx size=%zu",
+                 __get_str(dev_name), __entry->iova, __entry->paddr, 
__entry->size
        )
 );
 
 TRACE_EVENT(unmap,
 
-       TP_PROTO(unsigned long iova, size_t size, size_t unmapped_size),
+       TP_PROTO(unsigned long iova, size_t size, size_t unmapped_size, const 
char *dev_name),
 
-       TP_ARGS(iova, size, unmapped_size),
+       TP_ARGS(iova, size, unmapped_size, dev_name),
 
        TP_STRUCT__entry(
                __field(u64, iova)
                __field(size_t, size)
                __field(size_t, unmapped_size)
+               __string(dev_name, dev_name)
        ),
 
        TP_fast_assign(
                __entry->iova = iova;
                __entry->size = size;
                __entry->unmapped_size = unmapped_size;
+               __assign_str(dev_name, dev_name);
        ),
 
-       TP_printk("IOMMU: iova=0x%016llx size=%zu unmapped_size=%zu",
-                       __entry->iova, __entry->size, __entry->unmapped_size
+       TP_printk("IOMMU: dev=%s iova=0x%016llx size=%zu unmapped_size=%zu",
+                 __get_str(dev_name), __entry->iova, __entry->size, 
__entry->unmapped_size
        )
 );
 
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation

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