[PATCH v4 0/3] iommu/arm-smmu-v3: Parse out event records

[Pranjal Shrivastava <praan@google.com>]

Enhance the arm-smmu-v3 driver to parse out useful information from
event records into a structure for better event handling & logging.

As requested by Nicolin, some sample logs powered by QEMU:

[   85.410290] arm-smmu-v3 arm-smmu-v3.0.auto: Unexpected event received: F_PERMISSION
[   85.410290]  master: 0000:00:01.0 sid: 0x00000008.0x00000
[   85.410290]  iova = 0xffffc0d0 ipa = 0x0
[   85.410290]  Unpriv | Data | Write | S1 | Input address caused fault
[   85.410290]  STAG = 0x0 Stall = 0x0
[   85.411681] arm-smmu-v3 arm-smmu-v3.0.auto: event 0x13 received: master 0000:00:01.0:
[   85.412045] arm-smmu-v3 arm-smmu-v3.0.auto:  0x0000000800000013
[   85.412347] arm-smmu-v3 arm-smmu-v3.0.auto:  0x0000020000000000
[   85.412630] arm-smmu-v3 arm-smmu-v3.0.auto:  0x00000000ffffc0d0
[   85.412921] arm-smmu-v3 arm-smmu-v3.0.auto:  0x0000000000000000

..and a sample log for devices with a good name:

[   43.405187] arm-smmu-v3 arm-smmu-v3.0.auto: Unexpected event received: F_TRANSLATION
[   43.405187]  master: igb sid: 0x00000008.0x00000
[   43.405187]  iova = 0xfffff040 ipa = 0x0
[   43.405187]  Unpriv | Data | Write | S1 | CD fetch
[   43.405187]  STAG = 0x0 Stall = 0x0
[   43.406302] arm-smmu-v3 arm-smmu-v3.0.auto: event 0x10 received: master igb:
[   43.406622] arm-smmu-v3 arm-smmu-v3.0.auto:  0x0000000800000010
[   43.406875] arm-smmu-v3 arm-smmu-v3.0.auto:  0x0000000000000000
[   43.407131] arm-smmu-v3 arm-smmu-v3.0.auto:  0x00000000fffff040
[   43.407397] arm-smmu-v3 arm-smmu-v3.0.auto:  0x0000000000000000

v4
 * Re-arranged the series to first introduce struct arm_smmu_event
 * Improved the complex ternary expression that prints TTRnW info
 * Added consistent spacing to the logs & resized log strings
 * Moved ratelimiting within `arm_smmu_dump_event`
 * Refactored master_name printing by getting a ref to the device
 * Refactored `arm_smmu_handle_evt` to avoid redundant master lookup

v3
 https://lore.kernel.org/all/20240928005143.2378938-1-praan@google.com/
 * Fixed a potential race and null pointer deref for arm_smmu_master
 * Improved the logging approach by using multiple strings
 * Added logs for STAG & STALL fields for relevant events
 * Invoked the log function within `arm_smmu_handle_evt` routine
 * Rebased the changes

v2
 https://lore.kernel.org/linux-iommu/20240827193026.3993039-1-praan@google.com/
 * Addressed review comments
 * Introduced `struct arm_smmu_event` to hold relevant event fields
 * Broke out helper functions to populate & dump event info
 * Modified the event handler routines to use `struct arm_smmu_event`

v1
 https://lore.kernel.org/linux-iommu/20240816211722.1404070-1-praan@google.com/


Pranjal Shrivastava (3):
  iommu/arm-smmu-v3: Introduce struct arm_smmu_event
  iommu/arm-smmu-v3: Log better event records
  iommu/arm-smmu-v3: Avoid redundant master lookup in events

 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 174 ++++++++++++++++----
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h |  33 ++++
 2 files changed, 172 insertions(+), 35 deletions(-)

-- 
2.47.0.rc1.288.g06298d1525-goog