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

diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
index 0a111b281578ba0fc95b7902923e44ed2ae894bf..7413c11fb562e9f37215e9ea6a10ee3155c4a496 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);
+                       }
                }
        }