drm/i915/perf: Consider OA buffer boundary when zeroing out reports

For reports that are not powers of 2, reports at the end of the OA
buffer may get split across the buffer boundary. When zeroing out such
reports, take the split into consideration.

v2: Use OA_BUFFER_SIZE (Ashutosh)

Fixes: 09a36015d9a0 ("drm/i915/perf: Clear out entire reports after reading if not power of 2 size")
Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230616173402.699776-1-umesh.nerlige.ramappa@intel.com
(cherry picked from commit 40b1588a750240cbe8a83117aa785d778749a77c)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
index 0a111b2..7413c11 100644 (file)
--- a/drivers/gpu/drm/i915/i915_perf.c
+++ b/drivers/gpu/drm/i915/i915_perf.c
@@ -868,8 +868,17 @@ static int gen8_append_oa_reports(struct i915_perf_stream *stream,
                        oa_report_id_clear(stream, report32);
                        oa_timestamp_clear(stream, report32);
                } else {
+                       u8 *oa_buf_end = stream->oa_buffer.vaddr +
+                                        OA_BUFFER_SIZE;
+                       u32 part = oa_buf_end - (u8 *)report32;
+
                        /* Zero out the entire report */
-                       memset(report32, 0, report_size);
+                       if (report_size <= part) {
+                               memset(report32, 0, report_size);
+                       } else {
+                               memset(report32, 0, part);
+                               memset(oa_buf_base, 0, report_size - part);
+                       }
                }
        }