drm/v3d: Do not use intermediate storage when copying performance query results

Removing the intermediate buffer removes the last use of the
V3D_MAX_COUNTERS define, which will enable further driver cleanup.

While at it pull the 32 vs 64 bit copying decision outside the loop in
order to reduce the number of conditional instructions.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Reviewed-by: Maíra Canal <mcanal@igalia.com>
Signed-off-by: Maíra Canal <mcanal@igalia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240711135340.84617-9-tursulin@igalia.com

drivers/gpu/drm/v3d/v3d_sched.c

@@ -421,18 +421,23 @@ v3d_reset_timestamp_queries(struct v3d_cpu_job *job)
 	v3d_put_bo_vaddr(bo);
 }
 
-static void
-write_to_buffer(void *dst, u32 idx, bool do_64bit, u64 value)
+static void write_to_buffer_32(u32 *dst, unsigned int idx, u32 value)
 {
-	if (do_64bit) {
-		u64 *dst64 = (u64 *)dst;
+	dst[idx] = value;
+}
 
-		dst64[idx] = value;
-	} else {
-		u32 *dst32 = (u32 *)dst;
+static void write_to_buffer_64(u64 *dst, unsigned int idx, u64 value)
+{
+	dst[idx] = value;
+}
 
-		dst32[idx] = (u32)value;
-	}
+static void
+write_to_buffer(void *dst, unsigned int idx, bool do_64bit, u64 value)
+{
+	if (do_64bit)
+		write_to_buffer_64(dst, idx, value);
+	else
+		write_to_buffer_32(dst, idx, value);
 }
 
 static void
@@ -505,18 +510,24 @@ v3d_reset_performance_queries(struct v3d_cpu_job *job)
 }
 
 static void
-v3d_write_performance_query_result(struct v3d_cpu_job *job, void *data, u32 query)
+v3d_write_performance_query_result(struct v3d_cpu_job *job, void *data,
+				   unsigned int query)
 {
-	struct v3d_performance_query_info *performance_query = &job->performance_query;
-	struct v3d_copy_query_results_info *copy = &job->copy;
+	struct v3d_performance_query_info *performance_query =
+						&job->performance_query;
 	struct v3d_file_priv *v3d_priv = job->base.file->driver_priv;
+	struct v3d_performance_query *perf_query =
+			&performance_query->queries[query];
 	struct v3d_dev *v3d = job->base.v3d;
-	struct v3d_perfmon *perfmon;
-	u64 counter_values[V3D_MAX_COUNTERS];
+	unsigned int i, j, offset;
+
+	for (i = 0, offset = 0;
+	     i < performance_query->nperfmons;
+	     i++, offset += DRM_V3D_MAX_PERF_COUNTERS) {
+		struct v3d_perfmon *perfmon;
 
-	for (int i = 0; i < performance_query->nperfmons; i++) {
 		perfmon = v3d_perfmon_find(v3d_priv,
-					   performance_query->queries[query].kperfmon_ids[i]);
+					   perf_query->kperfmon_ids[i]);
 		if (!perfmon) {
 			DRM_DEBUG("Failed to find perfmon.");
 			continue;
@@ -524,14 +535,18 @@ v3d_write_performance_query_result(struct v3d_cpu_job *job, void *data, u32 quer
 
 		v3d_perfmon_stop(v3d, perfmon, true);
 
-		memcpy(&counter_values[i * DRM_V3D_MAX_PERF_COUNTERS], perfmon->values,
-		       perfmon->ncounters * sizeof(u64));
+		if (job->copy.do_64bit) {
+			for (j = 0; j < perfmon->ncounters; j++)
+				write_to_buffer_64(data, offset + j,
+						   perfmon->values[j]);
+		} else {
+			for (j = 0; j < perfmon->ncounters; j++)
+				write_to_buffer_32(data, offset + j,
+						   perfmon->values[j]);
+		}
 
 		v3d_perfmon_put(perfmon);
 	}
-
-	for (int i = 0; i < performance_query->ncounters; i++)
-		write_to_buffer(data, i, copy->do_64bit, counter_values[i]);
 }
 
 static void