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25 #include <linux/prime_numbers.h>
27 #include "../i915_selftest.h"
28 #include "i915_random.h"
30 static int cpu_set(struct drm_i915_gem_object *obj,
34 unsigned int needs_clflush;
39 err = i915_gem_obj_prepare_shmem_write(obj, &needs_clflush);
43 page = i915_gem_object_get_page(obj, offset >> PAGE_SHIFT);
44 map = kmap_atomic(page);
45 if (needs_clflush & CLFLUSH_BEFORE)
46 clflush(map+offset_in_page(offset) / sizeof(*map));
47 map[offset_in_page(offset) / sizeof(*map)] = v;
48 if (needs_clflush & CLFLUSH_AFTER)
49 clflush(map+offset_in_page(offset) / sizeof(*map));
52 i915_gem_obj_finish_shmem_access(obj);
56 static int cpu_get(struct drm_i915_gem_object *obj,
60 unsigned int needs_clflush;
65 err = i915_gem_obj_prepare_shmem_read(obj, &needs_clflush);
69 page = i915_gem_object_get_page(obj, offset >> PAGE_SHIFT);
70 map = kmap_atomic(page);
71 if (needs_clflush & CLFLUSH_BEFORE)
72 clflush(map+offset_in_page(offset) / sizeof(*map));
73 *v = map[offset_in_page(offset) / sizeof(*map)];
76 i915_gem_obj_finish_shmem_access(obj);
80 static int gtt_set(struct drm_i915_gem_object *obj,
88 err = i915_gem_object_set_to_gtt_domain(obj, true);
92 vma = i915_gem_object_ggtt_pin(obj, NULL, 0, 0, PIN_MAPPABLE);
96 map = i915_vma_pin_iomap(vma);
101 iowrite32(v, &map[offset / sizeof(*map)]);
102 i915_vma_unpin_iomap(vma);
107 static int gtt_get(struct drm_i915_gem_object *obj,
108 unsigned long offset,
111 struct i915_vma *vma;
115 err = i915_gem_object_set_to_gtt_domain(obj, false);
119 vma = i915_gem_object_ggtt_pin(obj, NULL, 0, 0, PIN_MAPPABLE);
123 map = i915_vma_pin_iomap(vma);
128 *v = ioread32(&map[offset / sizeof(*map)]);
129 i915_vma_unpin_iomap(vma);
134 static int wc_set(struct drm_i915_gem_object *obj,
135 unsigned long offset,
141 err = i915_gem_object_set_to_wc_domain(obj, true);
145 map = i915_gem_object_pin_map(obj, I915_MAP_WC);
149 map[offset / sizeof(*map)] = v;
150 i915_gem_object_unpin_map(obj);
155 static int wc_get(struct drm_i915_gem_object *obj,
156 unsigned long offset,
162 err = i915_gem_object_set_to_wc_domain(obj, false);
166 map = i915_gem_object_pin_map(obj, I915_MAP_WC);
170 *v = map[offset / sizeof(*map)];
171 i915_gem_object_unpin_map(obj);
176 static int gpu_set(struct drm_i915_gem_object *obj,
177 unsigned long offset,
180 struct drm_i915_private *i915 = to_i915(obj->base.dev);
181 struct i915_request *rq;
182 struct i915_vma *vma;
186 err = i915_gem_object_set_to_gtt_domain(obj, true);
190 vma = i915_gem_object_ggtt_pin(obj, NULL, 0, 0, 0);
194 rq = i915_request_alloc(i915->engine[RCS], i915->kernel_context);
200 cs = intel_ring_begin(rq, 4);
202 i915_request_add(rq);
207 if (INTEL_GEN(i915) >= 8) {
208 *cs++ = MI_STORE_DWORD_IMM_GEN4 | 1 << 22;
209 *cs++ = lower_32_bits(i915_ggtt_offset(vma) + offset);
210 *cs++ = upper_32_bits(i915_ggtt_offset(vma) + offset);
212 } else if (INTEL_GEN(i915) >= 4) {
213 *cs++ = MI_STORE_DWORD_IMM_GEN4 | MI_USE_GGTT;
215 *cs++ = i915_ggtt_offset(vma) + offset;
218 *cs++ = MI_STORE_DWORD_IMM | MI_MEM_VIRTUAL;
219 *cs++ = i915_ggtt_offset(vma) + offset;
223 intel_ring_advance(rq, cs);
225 err = i915_vma_move_to_active(vma, rq, EXEC_OBJECT_WRITE);
228 i915_request_add(rq);
233 static bool always_valid(struct drm_i915_private *i915)
238 static bool needs_fence_registers(struct drm_i915_private *i915)
240 return !i915_terminally_wedged(&i915->gpu_error);
243 static bool needs_mi_store_dword(struct drm_i915_private *i915)
245 if (i915_terminally_wedged(&i915->gpu_error))
248 return intel_engine_can_store_dword(i915->engine[RCS]);
251 static const struct igt_coherency_mode {
253 int (*set)(struct drm_i915_gem_object *, unsigned long offset, u32 v);
254 int (*get)(struct drm_i915_gem_object *, unsigned long offset, u32 *v);
255 bool (*valid)(struct drm_i915_private *i915);
256 } igt_coherency_mode[] = {
257 { "cpu", cpu_set, cpu_get, always_valid },
258 { "gtt", gtt_set, gtt_get, needs_fence_registers },
259 { "wc", wc_set, wc_get, always_valid },
260 { "gpu", gpu_set, NULL, needs_mi_store_dword },
264 static int igt_gem_coherency(void *arg)
266 const unsigned int ncachelines = PAGE_SIZE/64;
267 I915_RND_STATE(prng);
268 struct drm_i915_private *i915 = arg;
269 const struct igt_coherency_mode *read, *write, *over;
270 struct drm_i915_gem_object *obj;
271 unsigned long count, n;
272 u32 *offsets, *values;
275 /* We repeatedly write, overwrite and read from a sequence of
276 * cachelines in order to try and detect incoherency (unflushed writes
277 * from either the CPU or GPU). Each setter/getter uses our cache
278 * domain API which should prevent incoherency.
281 offsets = kmalloc_array(ncachelines, 2*sizeof(u32), GFP_KERNEL);
284 for (count = 0; count < ncachelines; count++)
285 offsets[count] = count * 64 + 4 * (count % 16);
287 values = offsets + ncachelines;
289 mutex_lock(&i915->drm.struct_mutex);
290 for (over = igt_coherency_mode; over->name; over++) {
294 if (!over->valid(i915))
297 for (write = igt_coherency_mode; write->name; write++) {
301 if (!write->valid(i915))
304 for (read = igt_coherency_mode; read->name; read++) {
308 if (!read->valid(i915))
311 for_each_prime_number_from(count, 1, ncachelines) {
312 obj = i915_gem_object_create_internal(i915, PAGE_SIZE);
318 i915_random_reorder(offsets, ncachelines, &prng);
319 for (n = 0; n < count; n++)
320 values[n] = prandom_u32_state(&prng);
322 for (n = 0; n < count; n++) {
323 err = over->set(obj, offsets[n], ~values[n]);
325 pr_err("Failed to set stale value[%ld/%ld] in object using %s, err=%d\n",
326 n, count, over->name, err);
331 for (n = 0; n < count; n++) {
332 err = write->set(obj, offsets[n], values[n]);
334 pr_err("Failed to set value[%ld/%ld] in object using %s, err=%d\n",
335 n, count, write->name, err);
340 for (n = 0; n < count; n++) {
343 err = read->get(obj, offsets[n], &found);
345 pr_err("Failed to get value[%ld/%ld] in object using %s, err=%d\n",
346 n, count, read->name, err);
350 if (found != values[n]) {
351 pr_err("Value[%ld/%ld] mismatch, (overwrite with %s) wrote [%s] %x read [%s] %x (inverse %x), at offset %x\n",
352 n, count, over->name,
353 write->name, values[n],
355 ~values[n], offsets[n]);
361 __i915_gem_object_release_unless_active(obj);
367 mutex_unlock(&i915->drm.struct_mutex);
372 __i915_gem_object_release_unless_active(obj);
376 int i915_gem_coherency_live_selftests(struct drm_i915_private *i915)
378 static const struct i915_subtest tests[] = {
379 SUBTEST(igt_gem_coherency),
382 return i915_subtests(tests, i915);