drm/amdgpu: use ktime rather than jiffies for benchmark results

To protect against wraparounds.

Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_benchmark.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_benchmark.c
index 0701b7dbf5f9032fa255f4c97c78a459779239b9..edc6377ec5ff2c7c534aa7b77da93ac55bbeab56 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_benchmark.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_benchmark.c
@@ -29,14 +29,13 @@
 #define AMDGPU_BENCHMARK_COMMON_MODES_N 17
 
 static int amdgpu_benchmark_do_move(struct amdgpu_device *adev, unsigned size,
-                                   uint64_t saddr, uint64_t daddr, int n)
+                                   uint64_t saddr, uint64_t daddr, int n, s64 *time_ms)
 {
-       unsigned long start_jiffies;
-       unsigned long end_jiffies;
+       ktime_t stime, etime;
        struct dma_fence *fence;
        int i, r;
 
-       start_jiffies = jiffies;
+       stime = ktime_get();
        for (i = 0; i < n; i++) {
                struct amdgpu_ring *ring = adev->mman.buffer_funcs_ring;
                r = amdgpu_copy_buffer(ring, saddr, daddr, size, NULL, &fence,
@@ -48,25 +47,28 @@ static int amdgpu_benchmark_do_move(struct amdgpu_device *adev, unsigned size,
                if (r)
                        goto exit_do_move;
        }
-       end_jiffies = jiffies;
-       r = jiffies_to_msecs(end_jiffies - start_jiffies);
 
 exit_do_move:
+       etime = ktime_get();
+       *time_ms = ktime_ms_delta(etime, stime);
+
        return r;
 }
 
 
 static void amdgpu_benchmark_log_results(struct amdgpu_device *adev,
                                         int n, unsigned size,
-                                        unsigned int time,
+                                        s64 time_ms,
                                         unsigned sdomain, unsigned ddomain,
                                         char *kind)
 {
-       unsigned int throughput = (n * (size >> 10)) / time;
+       s64 throughput = (n * (size >> 10));
+
+       throughput = div64_s64(throughput, time_ms);
 
        dev_info(adev->dev, "amdgpu: %s %u bo moves of %u kB from"
-                " %d to %d in %u ms, throughput: %u Mb/s or %u MB/s\n",
-                kind, n, size >> 10, sdomain, ddomain, time,
+                " %d to %d in %lld ms, throughput: %lld Mb/s or %lld MB/s\n",
+                kind, n, size >> 10, sdomain, ddomain, time_ms,
                 throughput * 8, throughput);
 }
 
@@ -76,6 +78,7 @@ static int amdgpu_benchmark_move(struct amdgpu_device *adev, unsigned size,
        struct amdgpu_bo *dobj = NULL;
        struct amdgpu_bo *sobj = NULL;
        uint64_t saddr, daddr;
+       s64 time_ms;
        int r, n;
 
        n = AMDGPU_BENCHMARK_ITERATIONS;
@@ -96,11 +99,11 @@ static int amdgpu_benchmark_move(struct amdgpu_device *adev, unsigned size,
                goto out_cleanup;
 
        if (adev->mman.buffer_funcs) {
-               r = amdgpu_benchmark_do_move(adev, size, saddr, daddr, n);
-               if (r < 0)
+               r = amdgpu_benchmark_do_move(adev, size, saddr, daddr, n, &time_ms);
+               if (r)
                        goto out_cleanup;
-               if (r > 0)
-                       amdgpu_benchmark_log_results(adev, n, size, r,
+               else
+                       amdgpu_benchmark_log_results(adev, n, size, time_ms,
                                                     sdomain, ddomain, "dma");
        }