4 files changed, 52 insertions, 1 deletions

diff --git a/lib/igt_rand.c b/lib/igt_rand.c
index 664a4764..16a6ba9b 100644
--- a/lib/igt_rand.c
+++ b/lib/igt_rand.c
@@ -23,6 +23,14 @@ uint32_t hars_petruska_f54_1_random(uint32_t *s)
 #undef rol
 }
 
+uint64_t hars_petruska_f54_1_random64(uint32_t *s)
+{
+	uint32_t l = hars_petruska_f54_1_random(s);
+	uint32_t h = hars_petruska_f54_1_random(s);
+
+	return (uint64_t)h << 32 | l;
+}
+
 uint32_t hars_petruska_f54_1_random_unsafe(void)
 {
 	return hars_petruska_f54_1_random(&global);
diff --git a/lib/igt_rand.h b/lib/igt_rand.h
index c9cb3243..00156804 100644
--- a/lib/igt_rand.h
+++ b/lib/igt_rand.h
@@ -27,6 +27,7 @@
 #include <stdint.h>
 
 uint32_t hars_petruska_f54_1_random(uint32_t *state);
+uint64_t hars_petruska_f54_1_random64(uint32_t *s);
 
 uint32_t hars_petruska_f54_1_random_seed(uint32_t seed);
 uint32_t hars_petruska_f54_1_random_unsafe(void);
diff --git a/tests/i915/gem_pwrite.c b/tests/i915/gem_pwrite.c
index 69f823d5..20e9728b 100644
--- a/tests/i915/gem_pwrite.c
+++ b/tests/i915/gem_pwrite.c
@@ -25,7 +25,6 @@
  *
  */
 
-#include "igt.h"
 #include <unistd.h>
 #include <stdlib.h>
 #include <stdint.h>
@@ -37,8 +36,12 @@
 #include <sys/stat.h>
 #include <sys/ioctl.h>
 #include <sys/time.h>
+
 #include "drm.h"
 
+#include "igt.h"
+#include "igt_rand.h"
+
 #define MiB(x) ((x) * 1024 * 1024)
 
 typedef void *(*mmap_fn_t)(int, uint32_t, uint64_t, uint64_t, unsigned int);
@@ -238,6 +241,41 @@ static void test_big_gtt(int fd, int scale, unsigned flags)
 	gem_close(fd, handle);
 }
 
+static void test_random(int fd)
+{
+	uint32_t prng = 0xdeadbeef;
+	unsigned long count;
+	uint32_t handle;
+	uint64_t *map;
+	uint64_t size;
+
+	gem_require_mmap_wc(fd);
+
+	size = min(intel_get_total_ram_mb() / 2,
+		    gem_mappable_aperture_size() + 4096);
+	intel_require_memory(1, size, CHECK_RAM);
+
+	handle = gem_create(fd, size);
+	map = gem_mmap__wc(fd, handle, 0, size, PROT_WRITE);
+
+	count = 0;
+	igt_until_timeout(5) {
+		uint64_t a = hars_petruska_f54_1_random64(&prng) % (size / sizeof(uint64_t));
+		uint64_t x = hars_petruska_f54_1_random64(&prng);
+
+		gem_write(fd, handle, a * sizeof(x), &x, sizeof(x));
+
+		gem_set_domain(fd, handle, I915_GEM_DOMAIN_WC, 0);
+		igt_assert_eq_u64(map[a], x);
+
+		count++;
+	}
+	igt_info("Completed %lu cycles\n", count);
+
+	munmap(map, handle);
+	gem_close(fd, handle);
+}
+
 uint32_t *src, dst;
 uint32_t *src_user, dst_stolen;
 int fd;
@@ -369,6 +407,9 @@ igt_main_args("s:", NULL, help_str, opt_handler, NULL)
 		gem_close(fd, dst_stolen);
 	}
 
+	igt_subtest_f("basic-random")
+		test_random(fd);
+
 	{
 		const struct mode {
 			const char *name;
diff --git a/tests/intel-ci/blacklist.txt b/tests/intel-ci/blacklist.txt
index 390e4fa0..8085719f 100644
--- a/tests/intel-ci/blacklist.txt
+++ b/tests/intel-ci/blacklist.txt
@@ -44,6 +44,7 @@ igt@gem_lut_handle(@.*)?
 igt@gem_mmap_gtt@.*(huge|swap|clflush|forked).*
 igt@gem_mmap@.*(swap|huge).*
 igt@gem_pread_after_blit(@.*)?
+igt@gem_pwrite@(?!.*basic).*
 igt@gem_read_read_speed(@.*)?
 igt@gem_render_linear_blits@(?!.*basic).*
 igt@gem_render_tiled_blits@(?!.*basic).*