[Intel-gfx] [PATCH 1/5] igt/gem_mmap_wc: Exercise mmap(wc) interface

Daniel Vetter daniel at ffwll.ch
Mon Nov 17 19:36:34 CET 2014


On Mon, Nov 17, 2014 at 11:37:19AM +0000, Chris Wilson wrote:
> +/**
> + * 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.

Nit: Since this is the same for gtt wc mappings shouldn't we mention that
this bypasses "all cpu caches and also the gpu system agent (used by gtt
mmaps)"? Otherwise awesome and it looks like Akash has not time to supply
the ioctl(invalid) == -EINVAL tests and take a look at this too and then
I'll pull it all in.
-Daniel

> + *
> + * 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
> diff --git a/lib/ioctl_wrappers.h b/lib/ioctl_wrappers.h
> index d13408c..9e7edad 100644
> --- a/lib/ioctl_wrappers.h
> +++ b/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:
>   *
> diff --git a/tests/.gitignore b/tests/.gitignore
> index 6e6ab58..07d3b5a 100644
> --- a/tests/.gitignore
> +++ b/tests/.gitignore
> @@ -58,6 +58,7 @@ 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
> diff --git a/tests/Makefile.am b/tests/Makefile.am
> index 3762737..78cbe04 100644
> --- a/tests/Makefile.am
> +++ b/tests/Makefile.am
> @@ -58,6 +58,8 @@ 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)
> diff --git a/tests/Makefile.sources b/tests/Makefile.sources
> index 2677bf7..97aab02 100644
> --- a/tests/Makefile.sources
> +++ b/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 \
> diff --git a/tests/gem_mmap_wc.c b/tests/gem_mmap_wc.c
> new file mode 100644
> index 0000000..87140ff
> --- /dev/null
> +++ b/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 at 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);
> +}
> -- 
> 1.9.1
> 
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> Intel-gfx at lists.freedesktop.org
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-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch



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