igt/gem_mmap_wc: Exercise mmap(wc) interface

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

lib/ioctl_wrappers.c

@@ -463,10 +463,91 @@ void *gem_mmap__gtt(int fd, uint32_t handle, int size, int prot)
 	ptr = mmap64(0, size, prot, MAP_SHARED, fd, mmap_arg.offset);
 	if (ptr == MAP_FAILED)
 		ptr = NULL;
+	else
+		errno = 0;
 
 	return ptr;
 }
 
+struct local_i915_gem_mmap_v2 {
+	uint32_t handle;
+	uint32_t pad;
+	uint64_t offset;
+	uint64_t size;
+	uint64_t addr_ptr;
+	uint64_t flags;
+#define I915_MMAP_WC 0x1
+};
+#define LOCAL_IOCTL_I915_GEM_MMAP_v2 DRM_IOWR(DRM_COMMAND_BASE + DRM_I915_GEM_MMAP, struct local_i915_gem_mmap_v2)
+
+bool gem_mmap__has_wc(int fd)
+{
+	static int has_wc = -1;
+
+	if (has_wc == -1) {
+		struct drm_i915_getparam gp;
+		int val = -1;
+
+		has_wc = 0;
+
+		memset(&gp, 0, sizeof(gp));
+		gp.param = 30; /* MMAP_VERSION */
+		gp.value = &val;
+
+		/* Do we have the new mmap_ioctl? */
+		ioctl(fd, DRM_IOCTL_I915_GETPARAM, &gp);
+		if (val >= 1) {
+			struct local_i915_gem_mmap_v2 arg;
+
+			/* Does this device support wc-mmaps ? */
+			memset(&arg, 0, sizeof(arg));
+			arg.handle = gem_create(fd, 4096);
+			arg.offset = 0;
+			arg.size = 4096;
+			arg.flags = I915_MMAP_WC;
+			has_wc = drmIoctl(fd, LOCAL_IOCTL_I915_GEM_MMAP_v2, &arg) == 0;
+			gem_close(fd, arg.handle);
+		}
+		errno = 0;
+	}
+
+	return has_wc > 0;
+}
+
+/**
+ * gem_mmap__wc:
+ * @fd: open i915 drm file descriptor
+ * @handle: gem buffer object handle
+ * @offset: offset in the gem buffer of te mmap arena
+ * @size: size of the mmap arena
+ * @prot: memory protection bits as used by mmap()
+ *
+ * This functions wraps up procedure to establish a memory mapping through
+ * direct cpu access, bypassing the gpu and cpu caches completely.
+ *
+ * Returns: A pointer to the created memory mapping.
+ */
+void *gem_mmap__wc(int fd, uint32_t handle, int offset, int size, int prot)
+{
+	struct local_i915_gem_mmap_v2 arg;
+
+	if (!gem_mmap__has_wc(fd)) {
+		errno = ENOSYS;
+		return NULL;
+	}
+
+	memset(&arg, 0, sizeof(arg));
+	arg.handle = handle;
+	arg.offset = offset;
+	arg.size = size;
+	arg.flags = I915_MMAP_WC;
+	if (drmIoctl(fd, LOCAL_IOCTL_I915_GEM_MMAP_v2, &arg))
+		return NULL;
+
+	errno = 0;
+	return (void *)(uintptr_t)arg.addr_ptr;
+}
+
 /**
  * gem_mmap__cpu:
  * @fd: open i915 drm file descriptor

lib/ioctl_wrappers.h

@@ -62,6 +62,11 @@ void gem_execbuf(int fd, struct drm_i915_gem_execbuffer2 *execbuf);
 
 void *gem_mmap__gtt(int fd, uint32_t handle, int size, int prot);
 void *gem_mmap__cpu(int fd, uint32_t handle, int offset, int size, int prot);
+
+bool gem_mmap__has_wc(int fd);
+void *gem_mmap__wc(int fd, uint32_t handle, int offset, int size, int prot);
+#define igt_require_mmap_wc(x) igt_require(gem_mmap__has_wc(x))
+
 /**
  * gem_mmap:
  *

tests/.gitignore

@@ -61,6 +61,7 @@ gem_madvise
 gem_media_fill
 gem_mmap
 gem_mmap_gtt
+gem_mmap_wc
 gem_mmap_offset_exhaustion
 gem_multi_bsd_sync_loop
 gem_non_secure_batch

tests/Makefile.am

@@ -60,6 +60,8 @@ gem_flink_race_CFLAGS = $(AM_CFLAGS) $(THREAD_CFLAGS)
 gem_flink_race_LDADD = $(LDADD) -lpthread
 gem_mmap_gtt_CFLAGS = $(AM_CFLAGS) $(THREAD_CFLAGS)
 gem_mmap_gtt_LDADD = $(LDADD) -lpthread
+gem_mmap_wc_CFLAGS = $(AM_CFLAGS) $(THREAD_CFLAGS)
+gem_mmap_wc_LDADD = $(LDADD) -lpthread
 gem_threaded_access_tiled_CFLAGS = $(AM_CFLAGS) $(THREAD_CFLAGS)
 gem_threaded_access_tiled_LDADD = $(LDADD) -lpthread
 gem_tiled_swapping_CFLAGS = $(AM_CFLAGS) $(THREAD_CFLAGS)

tests/Makefile.sources

@@ -42,6 +42,7 @@ TESTS_progs_M = \
 	gem_madvise \
 	gem_mmap \
 	gem_mmap_gtt \
+	gem_mmap_wc \
 	gem_partial_pwrite_pread \
 	gem_persistent_relocs \
 	gem_pipe_control_store_loop \

tests/gem_mmap_wc.c

@@ -0,0 +1,370 @@
+/*
+ * Copyright © 2011 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ * Authors:
+ *    Chris Wilson <chris@chris-wilson.co.uk>
+ *
+ */
+
+#define _GNU_SOURCE
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <pthread.h>
+#include <errno.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include "drm.h"
+#include "ioctl_wrappers.h"
+#include "drmtest.h"
+#include "igt_debugfs.h"
+
+static int OBJECT_SIZE = 16*1024*1024;
+
+static void set_domain(int fd, uint32_t handle)
+{
+	gem_set_domain(fd, handle, I915_GEM_DOMAIN_GTT, I915_GEM_DOMAIN_GTT);
+}
+
+static void *
+mmap_bo(int fd, uint32_t handle)
+{
+	void *ptr;
+
+	ptr = gem_mmap__wc(fd, handle, 0, OBJECT_SIZE, PROT_READ | PROT_WRITE);
+	igt_assert(ptr && ptr != MAP_FAILED);
+
+	return ptr;
+}
+
+static void *
+create_pointer(int fd)
+{
+	uint32_t handle;
+	void *ptr;
+
+	handle = gem_create(fd, OBJECT_SIZE);
+
+	ptr = mmap_bo(fd, handle);
+	set_domain(fd, handle);
+
+	gem_close(fd, handle);
+
+	return ptr;
+}
+
+static void
+test_copy(int fd)
+{
+	void *src, *dst;
+
+	igt_require_mmap_wc(fd);
+
+	/* copy from a fresh src to fresh dst to force pagefault on both */
+	src = create_pointer(fd);
+	dst = create_pointer(fd);
+
+	memcpy(dst, src, OBJECT_SIZE);
+	memcpy(src, dst, OBJECT_SIZE);
+
+	munmap(dst, OBJECT_SIZE);
+	munmap(src, OBJECT_SIZE);
+}
+
+enum test_read_write {
+	READ_BEFORE_WRITE,
+	READ_AFTER_WRITE,
+};
+
+static void
+test_read_write(int fd, enum test_read_write order)
+{
+	uint32_t handle;
+	void *ptr;
+	volatile uint32_t val = 0;
+
+	handle = gem_create(fd, OBJECT_SIZE);
+	set_domain(fd, handle);
+
+	ptr = mmap_bo(fd, handle);
+	igt_assert(ptr != MAP_FAILED);
+
+	if (order == READ_BEFORE_WRITE) {
+		val = *(uint32_t *)ptr;
+		*(uint32_t *)ptr = val;
+	} else {
+		*(uint32_t *)ptr = val;
+		val = *(uint32_t *)ptr;
+	}
+
+	gem_close(fd, handle);
+	munmap(ptr, OBJECT_SIZE);
+}
+
+static void
+test_read_write2(int fd, enum test_read_write order)
+{
+	uint32_t handle;
+	void *r, *w;
+	volatile uint32_t val = 0;
+
+	igt_require_mmap_wc(fd);
+
+	handle = gem_create(fd, OBJECT_SIZE);
+	set_domain(fd, handle);
+
+	r = gem_mmap__wc(fd, handle, 0, OBJECT_SIZE, PROT_READ);
+	igt_assert(r != MAP_FAILED);
+
+	w = gem_mmap__wc(fd, handle, 0, OBJECT_SIZE, PROT_READ | PROT_WRITE);
+	igt_assert(w != MAP_FAILED);
+
+	if (order == READ_BEFORE_WRITE) {
+		val = *(uint32_t *)r;
+		*(uint32_t *)w = val;
+	} else {
+		*(uint32_t *)w = val;
+		val = *(uint32_t *)r;
+	}
+
+	gem_close(fd, handle);
+	munmap(r, OBJECT_SIZE);
+	munmap(w, OBJECT_SIZE);
+}
+
+static void
+test_write(int fd)
+{
+	void *src;
+	uint32_t dst;
+
+	igt_require_mmap_wc(fd);
+
+	/* copy from a fresh src to fresh dst to force pagefault on both */
+	src = create_pointer(fd);
+	dst = gem_create(fd, OBJECT_SIZE);
+
+	gem_write(fd, dst, 0, src, OBJECT_SIZE);
+
+	gem_close(fd, dst);
+	munmap(src, OBJECT_SIZE);
+}
+
+static void
+test_write_gtt(int fd)
+{
+	uint32_t dst;
+	char *dst_gtt;
+	void *src;
+
+	igt_require_mmap_wc(fd);
+
+	dst = gem_create(fd, OBJECT_SIZE);
+	set_domain(fd, dst);
+
+	/* prefault object into gtt */
+	dst_gtt = mmap_bo(fd, dst);
+	memset(dst_gtt, 0, OBJECT_SIZE);
+	munmap(dst_gtt, OBJECT_SIZE);
+
+	src = create_pointer(fd);
+
+	gem_write(fd, dst, 0, src, OBJECT_SIZE);
+
+	gem_close(fd, dst);
+	munmap(src, OBJECT_SIZE);
+}
+
+static void
+test_read(int fd)
+{
+	void *dst;
+	uint32_t src;
+
+	igt_require_mmap_wc(fd);
+
+	/* copy from a fresh src to fresh dst to force pagefault on both */
+	dst = create_pointer(fd);
+	src = gem_create(fd, OBJECT_SIZE);
+
+	gem_read(fd, src, 0, dst, OBJECT_SIZE);
+
+	gem_close(fd, src);
+	munmap(dst, OBJECT_SIZE);
+}
+
+static void
+test_write_cpu_read_wc(int fd)
+{
+	uint32_t handle;
+	uint32_t *src, *dst;
+
+	igt_require_mmap_wc(fd);
+
+	handle = gem_create(fd, OBJECT_SIZE);
+
+	dst = gem_mmap__wc(fd, handle, 0, OBJECT_SIZE, PROT_READ);
+	igt_assert(dst != (uint32_t *)MAP_FAILED);
+
+	src = gem_mmap__cpu(fd, handle, 0, OBJECT_SIZE, PROT_WRITE);
+	igt_assert(src != (uint32_t *)MAP_FAILED);
+
+	gem_close(fd, handle);
+
+	memset(src, 0xaa, OBJECT_SIZE);
+	set_domain(fd, handle);
+	igt_assert(memcmp(dst, src, OBJECT_SIZE) == 0);
+
+	munmap(src, OBJECT_SIZE);
+	munmap(dst, OBJECT_SIZE);
+}
+
+static void
+test_write_gtt_read_wc(int fd)
+{
+	uint32_t handle;
+	uint32_t *src, *dst;
+
+	igt_require_mmap_wc(fd);
+
+	handle = gem_create(fd, OBJECT_SIZE);
+	set_domain(fd, handle);
+
+	dst = gem_mmap__wc(fd, handle, 0, OBJECT_SIZE, PROT_READ);
+	igt_assert(dst != (uint32_t *)MAP_FAILED);
+
+	src = gem_mmap__gtt(fd, handle, OBJECT_SIZE, PROT_WRITE);
+	igt_assert(src != (uint32_t *)MAP_FAILED);
+
+	gem_close(fd, handle);
+
+	memset(src, 0xaa, OBJECT_SIZE);
+	igt_assert(memcmp(dst, src, OBJECT_SIZE) == 0);
+
+	munmap(src, OBJECT_SIZE);
+	munmap(dst, OBJECT_SIZE);
+}
+
+struct thread_fault_concurrent {
+	pthread_t thread;
+	int id;
+	uint32_t **ptr;
+};
+
+static void *
+thread_fault_concurrent(void *closure)
+{
+	struct thread_fault_concurrent *t = closure;
+	uint32_t val = 0;
+	int n;
+
+	for (n = 0; n < 32; n++) {
+		if (n & 1)
+			*t->ptr[(n + t->id) % 32] = val;
+		else
+			val = *t->ptr[(n + t->id) % 32];
+	}
+
+	return NULL;
+}
+
+static void
+test_fault_concurrent(int fd)
+{
+	uint32_t *ptr[32];
+	struct thread_fault_concurrent thread[64];
+	int n;
+
+	igt_require_mmap_wc(fd);
+
+	for (n = 0; n < 32; n++) {
+		ptr[n] = create_pointer(fd);
+	}
+
+	for (n = 0; n < 64; n++) {
+		thread[n].ptr = ptr;
+		thread[n].id = n;
+		pthread_create(&thread[n].thread, NULL, thread_fault_concurrent, &thread[n]);
+	}
+
+	for (n = 0; n < 64; n++)
+		pthread_join(thread[n].thread, NULL);
+
+	for (n = 0; n < 32; n++) {
+		munmap(ptr[n], OBJECT_SIZE);
+	}
+}
+
+static void
+run_without_prefault(int fd,
+			void (*func)(int fd))
+{
+	igt_disable_prefault();
+	func(fd);
+	igt_enable_prefault();
+}
+
+int fd;
+
+igt_main
+{
+	if (igt_run_in_simulation())
+		OBJECT_SIZE = 1 * 1024 * 1024;
+
+	igt_fixture
+		fd = drm_open_any();
+
+	igt_subtest("copy")
+		test_copy(fd);
+	igt_subtest("read")
+		test_read(fd);
+	igt_subtest("write")
+		test_write(fd);
+	igt_subtest("write-gtt")
+		test_write_gtt(fd);
+	igt_subtest("read-write")
+		test_read_write(fd, READ_BEFORE_WRITE);
+	igt_subtest("write-read")
+		test_read_write(fd, READ_AFTER_WRITE);
+	igt_subtest("read-write-distinct")
+		test_read_write2(fd, READ_BEFORE_WRITE);
+	igt_subtest("write-read-distinct")
+		test_read_write2(fd, READ_AFTER_WRITE);
+	igt_subtest("fault-concurrent")
+		test_fault_concurrent(fd);
+	igt_subtest("read-no-prefault")
+		run_without_prefault(fd, test_read);
+	igt_subtest("write-no-prefault")
+		run_without_prefault(fd, test_write);
+	igt_subtest("write-gtt-no-prefault")
+		run_without_prefault(fd, test_write_gtt);
+	igt_subtest("write-cpu-read-wc")
+		test_write_cpu_read_wc(fd);
+	igt_subtest("write-gtt-read-wc")
+		test_write_gtt_read_wc(fd);
+
+	igt_fixture
+		close(fd);
+}