drm/i915/selftests: Use a random engine for GEM coherency tests

Select a random user accessible engine for checking coherency results.
While we should check all engines, we use a random selection so that
over repeated runs we cover all.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191027225808.19437-4-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_coherency.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_coherency.c
index 0877ef4..0a195e5 100644 (file)
--- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_coherency.c
+++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_coherency.c
@@ -13,9 +13,12 @@
 #include "i915_selftest.h"
 #include "selftests/i915_random.h"
 
-static int cpu_set(struct drm_i915_gem_object *obj,
-                  unsigned long offset,
-                  u32 v)
+struct context {
+       struct drm_i915_gem_object *obj;
+       struct intel_engine_cs *engine;
+};
+
+static int cpu_set(struct context *ctx, unsigned long offset, u32 v)
 {
        unsigned int needs_clflush;
        struct page *page;
@@ -23,11 +26,11 @@ static int cpu_set(struct drm_i915_gem_object *obj,
        u32 *cpu;
        int err;
 
-       err = i915_gem_object_prepare_write(obj, &needs_clflush);
+       err = i915_gem_object_prepare_write(ctx->obj, &needs_clflush);
        if (err)
                return err;
 
-       page = i915_gem_object_get_page(obj, offset >> PAGE_SHIFT);
+       page = i915_gem_object_get_page(ctx->obj, offset >> PAGE_SHIFT);
        map = kmap_atomic(page);
        cpu = map + offset_in_page(offset);
 
@@ -40,14 +43,12 @@ static int cpu_set(struct drm_i915_gem_object *obj,
                drm_clflush_virt_range(cpu, sizeof(*cpu));
 
        kunmap_atomic(map);
-       i915_gem_object_finish_access(obj);
+       i915_gem_object_finish_access(ctx->obj);
 
        return 0;
 }
 
-static int cpu_get(struct drm_i915_gem_object *obj,
-                  unsigned long offset,
-                  u32 *v)
+static int cpu_get(struct context *ctx, unsigned long offset, u32 *v)
 {
        unsigned int needs_clflush;
        struct page *page;
@@ -55,11 +56,11 @@ static int cpu_get(struct drm_i915_gem_object *obj,
        u32 *cpu;
        int err;
 
-       err = i915_gem_object_prepare_read(obj, &needs_clflush);
+       err = i915_gem_object_prepare_read(ctx->obj, &needs_clflush);
        if (err)
                return err;
 
-       page = i915_gem_object_get_page(obj, offset >> PAGE_SHIFT);
+       page = i915_gem_object_get_page(ctx->obj, offset >> PAGE_SHIFT);
        map = kmap_atomic(page);
        cpu = map + offset_in_page(offset);
 
@@ -69,26 +70,24 @@ static int cpu_get(struct drm_i915_gem_object *obj,
        *v = *cpu;
 
        kunmap_atomic(map);
-       i915_gem_object_finish_access(obj);
+       i915_gem_object_finish_access(ctx->obj);
 
        return 0;
 }
 
-static int gtt_set(struct drm_i915_gem_object *obj,
-                  unsigned long offset,
-                  u32 v)
+static int gtt_set(struct context *ctx, unsigned long offset, u32 v)
 {
        struct i915_vma *vma;
        u32 __iomem *map;
        int err = 0;
 
-       i915_gem_object_lock(obj);
-       err = i915_gem_object_set_to_gtt_domain(obj, true);
-       i915_gem_object_unlock(obj);
+       i915_gem_object_lock(ctx->obj);
+       err = i915_gem_object_set_to_gtt_domain(ctx->obj, true);
+       i915_gem_object_unlock(ctx->obj);
        if (err)
                return err;
 
-       vma = i915_gem_object_ggtt_pin(obj, NULL, 0, 0, PIN_MAPPABLE);
+       vma = i915_gem_object_ggtt_pin(ctx->obj, NULL, 0, 0, PIN_MAPPABLE);
        if (IS_ERR(vma))
                return PTR_ERR(vma);
 
@@ -109,21 +108,19 @@ out_rpm:
        return err;
 }
 
-static int gtt_get(struct drm_i915_gem_object *obj,
-                  unsigned long offset,
-                  u32 *v)
+static int gtt_get(struct context *ctx, unsigned long offset, u32 *v)
 {
        struct i915_vma *vma;
        u32 __iomem *map;
        int err = 0;
 
-       i915_gem_object_lock(obj);
-       err = i915_gem_object_set_to_gtt_domain(obj, false);
-       i915_gem_object_unlock(obj);
+       i915_gem_object_lock(ctx->obj);
+       err = i915_gem_object_set_to_gtt_domain(ctx->obj, false);
+       i915_gem_object_unlock(ctx->obj);
        if (err)
                return err;
 
-       vma = i915_gem_object_ggtt_pin(obj, NULL, 0, 0, PIN_MAPPABLE);
+       vma = i915_gem_object_ggtt_pin(ctx->obj, NULL, 0, 0, PIN_MAPPABLE);
        if (IS_ERR(vma))
                return PTR_ERR(vma);
 
@@ -144,73 +141,66 @@ out_rpm:
        return err;
 }
 
-static int wc_set(struct drm_i915_gem_object *obj,
-                 unsigned long offset,
-                 u32 v)
+static int wc_set(struct context *ctx, unsigned long offset, u32 v)
 {
        u32 *map;
        int err;
 
-       i915_gem_object_lock(obj);
-       err = i915_gem_object_set_to_wc_domain(obj, true);
-       i915_gem_object_unlock(obj);
+       i915_gem_object_lock(ctx->obj);
+       err = i915_gem_object_set_to_wc_domain(ctx->obj, true);
+       i915_gem_object_unlock(ctx->obj);
        if (err)
                return err;
 
-       map = i915_gem_object_pin_map(obj, I915_MAP_WC);
+       map = i915_gem_object_pin_map(ctx->obj, I915_MAP_WC);
        if (IS_ERR(map))
                return PTR_ERR(map);
 
        map[offset / sizeof(*map)] = v;
-       i915_gem_object_unpin_map(obj);
+       i915_gem_object_unpin_map(ctx->obj);
 
        return 0;
 }
 
-static int wc_get(struct drm_i915_gem_object *obj,
-                 unsigned long offset,
-                 u32 *v)
+static int wc_get(struct context *ctx, unsigned long offset, u32 *v)
 {
        u32 *map;
        int err;
 
-       i915_gem_object_lock(obj);
-       err = i915_gem_object_set_to_wc_domain(obj, false);
-       i915_gem_object_unlock(obj);
+       i915_gem_object_lock(ctx->obj);
+       err = i915_gem_object_set_to_wc_domain(ctx->obj, false);
+       i915_gem_object_unlock(ctx->obj);
        if (err)
                return err;
 
-       map = i915_gem_object_pin_map(obj, I915_MAP_WC);
+       map = i915_gem_object_pin_map(ctx->obj, I915_MAP_WC);
        if (IS_ERR(map))
                return PTR_ERR(map);
 
        *v = map[offset / sizeof(*map)];
-       i915_gem_object_unpin_map(obj);
+       i915_gem_object_unpin_map(ctx->obj);
 
        return 0;
 }
 
-static int gpu_set(struct drm_i915_gem_object *obj,
-                  unsigned long offset,
-                  u32 v)
+static int gpu_set(struct context *ctx, unsigned long offset, u32 v)
 {
-       struct drm_i915_private *i915 = to_i915(obj->base.dev);
        struct i915_request *rq;
        struct i915_vma *vma;
        u32 *cs;
        int err;
 
-       i915_gem_object_lock(obj);
-       err = i915_gem_object_set_to_gtt_domain(obj, true);
-       i915_gem_object_unlock(obj);
+       i915_gem_object_lock(ctx->obj);
+       err = i915_gem_object_set_to_gtt_domain(ctx->obj, true);
+       i915_gem_object_unlock(ctx->obj);
        if (err)
                return err;
 
-       vma = i915_gem_object_ggtt_pin(obj, NULL, 0, 0, 0);
+       vma = i915_gem_object_ggtt_pin(ctx->obj, NULL, 0, 0, 0);
        if (IS_ERR(vma))
                return PTR_ERR(vma);
 
-       rq = i915_request_create(i915->engine[RCS0]->kernel_context);
+       rq = i915_request_create(ctx->engine->kernel_context);
        if (IS_ERR(rq)) {
                i915_vma_unpin(vma);
                return PTR_ERR(rq);
@@ -223,12 +213,12 @@ static int gpu_set(struct drm_i915_gem_object *obj,
                return PTR_ERR(cs);
        }
 
-       if (INTEL_GEN(i915) >= 8) {
+       if (INTEL_GEN(ctx->engine->i915) >= 8) {
                *cs++ = MI_STORE_DWORD_IMM_GEN4 | 1 << 22;
                *cs++ = lower_32_bits(i915_ggtt_offset(vma) + offset);
                *cs++ = upper_32_bits(i915_ggtt_offset(vma) + offset);
                *cs++ = v;
-       } else if (INTEL_GEN(i915) >= 4) {
+       } else if (INTEL_GEN(ctx->engine->i915) >= 4) {
                *cs++ = MI_STORE_DWORD_IMM_GEN4 | MI_USE_GGTT;
                *cs++ = 0;
                *cs++ = i915_ggtt_offset(vma) + offset;
@@ -253,32 +243,29 @@ static int gpu_set(struct drm_i915_gem_object *obj,
        return err;
 }
 
-static bool always_valid(struct drm_i915_private *i915)
+static bool always_valid(struct context *ctx)
 {
        return true;
 }
 
-static bool needs_fence_registers(struct drm_i915_private *i915)
+static bool needs_fence_registers(struct context *ctx)
 {
-       return !intel_gt_is_wedged(&i915->gt);
+       return !intel_gt_is_wedged(ctx->engine->gt);
 }
 
-static bool needs_mi_store_dword(struct drm_i915_private *i915)
+static bool needs_mi_store_dword(struct context *ctx)
 {
-       if (intel_gt_is_wedged(&i915->gt))
-               return false;
-
-       if (!HAS_ENGINE(i915, RCS0))
+       if (intel_gt_is_wedged(ctx->engine->gt))
                return false;
 
-       return intel_engine_can_store_dword(i915->engine[RCS0]);
+       return intel_engine_can_store_dword(ctx->engine);
 }
 
 static const struct igt_coherency_mode {
        const char *name;
-       int (*set)(struct drm_i915_gem_object *, unsigned long offset, u32 v);
-       int (*get)(struct drm_i915_gem_object *, unsigned long offset, u32 *v);
-       bool (*valid)(struct drm_i915_private *i915);
+       int (*set)(struct context *ctx, unsigned long offset, u32 v);
+       int (*get)(struct context *ctx, unsigned long offset, u32 *v);
+       bool (*valid)(struct context *ctx);
 } igt_coherency_mode[] = {
        { "cpu", cpu_set, cpu_get, always_valid },
        { "gtt", gtt_set, gtt_get, needs_fence_registers },
@@ -287,18 +274,37 @@ static const struct igt_coherency_mode {
        { },
 };
 
+static struct intel_engine_cs *
+random_engine(struct drm_i915_private *i915, struct rnd_state *prng)
+{
+       struct intel_engine_cs *engine;
+       unsigned int count;
+
+       count = 0;
+       for_each_uabi_engine(engine, i915)
+               count++;
+
+       count = i915_prandom_u32_max_state(count, prng);
+       for_each_uabi_engine(engine, i915)
+               if (count-- == 0)
+                       return engine;
+
+       return NULL;
+}
+
 static int igt_gem_coherency(void *arg)
 {
        const unsigned int ncachelines = PAGE_SIZE/64;
-       I915_RND_STATE(prng);
        struct drm_i915_private *i915 = arg;
        const struct igt_coherency_mode *read, *write, *over;
-       struct drm_i915_gem_object *obj;
        unsigned long count, n;
        u32 *offsets, *values;
+       I915_RND_STATE(prng);
+       struct context ctx;
        int err = 0;
 
-       /* We repeatedly write, overwrite and read from a sequence of
+       /*
+        * We repeatedly write, overwrite and read from a sequence of
         * cachelines in order to try and detect incoherency (unflushed writes
         * from either the CPU or GPU). Each setter/getter uses our cache
         * domain API which should prevent incoherency.
@@ -312,31 +318,35 @@ static int igt_gem_coherency(void *arg)
 
        values = offsets + ncachelines;
 
+       ctx.engine = random_engine(i915, &prng);
+       GEM_BUG_ON(!ctx.engine);
+       pr_info("%s: using %s\n", __func__, ctx.engine->name);
+
        for (over = igt_coherency_mode; over->name; over++) {
                if (!over->set)
                        continue;
 
-               if (!over->valid(i915))
+               if (!over->valid(&ctx))
                        continue;
 
                for (write = igt_coherency_mode; write->name; write++) {
                        if (!write->set)
                                continue;
 
-                       if (!write->valid(i915))
+                       if (!write->valid(&ctx))
                                continue;
 
                        for (read = igt_coherency_mode; read->name; read++) {
                                if (!read->get)
                                        continue;
 
-                               if (!read->valid(i915))
+                               if (!read->valid(&ctx))
                                        continue;
 
                                for_each_prime_number_from(count, 1, ncachelines) {
-                                       obj = i915_gem_object_create_internal(i915, PAGE_SIZE);
-                                       if (IS_ERR(obj)) {
-                                               err = PTR_ERR(obj);
+                                       ctx.obj = i915_gem_object_create_internal(i915, PAGE_SIZE);
+                                       if (IS_ERR(ctx.obj)) {
+                                               err = PTR_ERR(ctx.obj);
                                                goto free;
                                        }
 
@@ -345,7 +355,7 @@ static int igt_gem_coherency(void *arg)
                                                values[n] = prandom_u32_state(&prng);
 
                                        for (n = 0; n < count; n++) {
-                                               err = over->set(obj, offsets[n], ~values[n]);
+                                               err = over->set(&ctx, offsets[n], ~values[n]);
                                                if (err) {
                                                        pr_err("Failed to set stale value[%ld/%ld] in object using %s, err=%d\n",
                                                               n, count, over->name, err);
@@ -354,7 +364,7 @@ static int igt_gem_coherency(void *arg)
                                        }
 
                                        for (n = 0; n < count; n++) {
-                                               err = write->set(obj, offsets[n], values[n]);
+                                               err = write->set(&ctx, offsets[n], values[n]);
                                                if (err) {
                                                        pr_err("Failed to set value[%ld/%ld] in object using %s, err=%d\n",
                                                               n, count, write->name, err);
@@ -365,7 +375,7 @@ static int igt_gem_coherency(void *arg)
                                        for (n = 0; n < count; n++) {
                                                u32 found;
 
-                                               err = read->get(obj, offsets[n], &found);
+                                               err = read->get(&ctx, offsets[n], &found);
                                                if (err) {
                                                        pr_err("Failed to get value[%ld/%ld] in object using %s, err=%d\n",
                                                               n, count, read->name, err);
@@ -383,7 +393,7 @@ static int igt_gem_coherency(void *arg)
                                                }
                                        }
 
-                                       i915_gem_object_put(obj);
+                                       i915_gem_object_put(ctx.obj);
                                }
                        }
                }
@@ -393,7 +403,7 @@ free:
        return err;
 
 put_object:
-       i915_gem_object_put(obj);
+       i915_gem_object_put(ctx.obj);
        goto free;
 }