[PATCH 3/7] prime_mmap: Add basic tests to write in a bo using CPU

[Daniel Vetter]

On Thu, Aug 13, 2015 at 11:26:57AM -0300, Tiago Vignatti wrote:
> On 08/13/2015 04:01 AM, Daniel Vetter wrote:
> >On Wed, Aug 12, 2015 at 08:29:16PM -0300, Tiago Vignatti wrote:
> >>This patch adds test_correct_cpu_write, which maps the texture buffer through a
> >>prime fd and then writes directly to it using the CPU. It stresses the driver
> >>to guarantee cache synchronization among the different domains.
> >>
> >>This test also adds test_forked_cpu_write, which creates the GEM bo in one
> >>process and pass the prime handle of the it to another process, which in turn
> >>uses the handle only to map and write. Grossly speaking this test simulates
> >>Chrome OS  architecture, where the Web content ("unpriviledged process") maps
> >>and CPU-draws a buffer, which was previously allocated in the GPU process
> >>("priviledged process").
> >>
> >>This requires kernel modifications (Daniel Thompson's "drm: prime: Honour
> >>O_RDWR during prime-handle-to-fd").
> >>
> >>Signed-off-by: Tiago Vignatti <tiago.vignatti at intel.com>
> >
> >Squash with previous patch?
> 
> why? if the whole point is to decrease the amount of patches, then I prefer
> to squash 2/7 with the 1/7 (although they're from different authors and
> would be nice to keep separately the changes from each). This patch here
> introduces this writing to mmap'ed dma-buf fd, a concept that is still in
> debate, requiring a kernel counter-part so that's why I preferred to keep it
> away.

Replied to the wrong patch, I meant merging patch 1&2 ofc ;-)
-Daniel

> 
> 
> >>---
> >>  lib/ioctl_wrappers.c |  5 +++-
> >>  tests/prime_mmap.c   | 65 ++++++++++++++++++++++++++++++++++++++++++++++++++++
> >>  2 files changed, 69 insertions(+), 1 deletion(-)
> >>
> >>diff --git a/lib/ioctl_wrappers.c b/lib/ioctl_wrappers.c
> >>index 53bd635..941fa66 100644
> >>--- a/lib/ioctl_wrappers.c
> >>+++ b/lib/ioctl_wrappers.c
> >>@@ -1125,6 +1125,9 @@ void gem_require_ring(int fd, int ring_id)
> >>
> >>  /* prime */
> >>
> >>+#ifndef DRM_RDWR
> >>+#define DRM_RDWR O_RDWR
> >>+#endif
> >>  /**
> >>   * prime_handle_to_fd:
> >>   * @fd: open i915 drm file descriptor
> >>@@ -1142,7 +1145,7 @@ int prime_handle_to_fd(int fd, uint32_t handle)
> >>
> >>  	memset(&args, 0, sizeof(args));
> >>  	args.handle = handle;
> >>-	args.flags = DRM_CLOEXEC;
> >>+	args.flags = DRM_CLOEXEC | DRM_RDWR;
> >
> >This needs to be optional otherwise all the existing prime tests start
> >falling over on older kernels. Probably need a
> >prime_handle_to_fd_with_mmap, which doesn an igt_skip if it fails.
> 
> true. Thank you.
> 
> 
> >-Daniel
> >
> >>  	args.fd = -1;
> >>
> >>  	do_ioctl(fd, DRM_IOCTL_PRIME_HANDLE_TO_FD, &args);
> >>diff --git a/tests/prime_mmap.c b/tests/prime_mmap.c
> >>index dc59e8f..ad91371 100644
> >>--- a/tests/prime_mmap.c
> >>+++ b/tests/prime_mmap.c
> >>@@ -22,6 +22,7 @@
> >>   *
> >>   * Authors:
> >>   *    Rob Bradford <rob at linux.intel.com>
> >>+ *    Tiago Vignatti <tiago.vignatti at intel.com>
> >>   *
> >>   */
> >>
> >>@@ -66,6 +67,12 @@ fill_bo(uint32_t handle, size_t size)
> >>  }
> >>
> >>  static void
> >>+fill_bo_cpu(char *ptr)
> >>+{
> >>+	memcpy(ptr, pattern, sizeof(pattern));
> >>+}
> >>+
> >>+static void
> >>  test_correct(void)
> >>  {
> >>  	int dma_buf_fd;
> >>@@ -180,6 +187,62 @@ test_forked(void)
> >>  	gem_close(fd, handle);
> >>  }
> >>
> >>+/* test CPU write. This has a rather big implication for the driver which must
> >>+ * guarantee cache synchronization when writing the bo using CPU. */
> >>+static void
> >>+test_correct_cpu_write(void)
> >>+{
> >>+	int dma_buf_fd;
> >>+	char *ptr;
> >>+	uint32_t handle;
> >>+
> >>+	handle = gem_create(fd, BO_SIZE);
> >>+
> >>+	dma_buf_fd = prime_handle_to_fd(fd, handle);
> >>+	igt_assert(errno == 0);
> >>+
> >>+	/* Check correctness of map using write protection (PROT_WRITE) */
> >>+	ptr = mmap(NULL, BO_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, dma_buf_fd, 0);
> >>+	igt_assert(ptr != MAP_FAILED);
> >>+
> >>+	/* Fill bo using CPU */
> >>+	fill_bo_cpu(ptr);
> >>+
> >>+	/* Check pattern correctness */
> >>+	igt_assert(memcmp(ptr, pattern, sizeof(pattern)) == 0);
> >>+
> >>+	munmap(ptr, BO_SIZE);
> >>+	close(dma_buf_fd);
> >>+	gem_close(fd, handle);
> >>+}
> >>+
> >>+/* map from another process and then write using CPU */
> >>+static void
> >>+test_forked_cpu_write(void)
> >>+{
> >>+	int dma_buf_fd;
> >>+	char *ptr;
> >>+	uint32_t handle;
> >>+
> >>+	handle = gem_create(fd, BO_SIZE);
> >>+
> >>+	dma_buf_fd = prime_handle_to_fd(fd, handle);
> >>+	igt_assert(errno == 0);
> >>+
> >>+	igt_fork(childno, 1) {
> >>+		ptr = mmap(NULL, BO_SIZE, PROT_READ | PROT_WRITE , MAP_SHARED, dma_buf_fd, 0);
> >>+		igt_assert(ptr != MAP_FAILED);
> >>+		fill_bo_cpu(ptr);
> >>+
> >>+		igt_assert(memcmp(ptr, pattern, sizeof(pattern)) == 0);
> >>+		munmap(ptr, BO_SIZE);
> >>+		close(dma_buf_fd);
> >>+	}
> >>+	close(dma_buf_fd);
> >>+	igt_waitchildren();
> >>+	gem_close(fd, handle);
> >>+}
> >>+
> >>  static void
> >>  test_refcounting(void)
> >>  {
> >>@@ -346,6 +409,8 @@ igt_main
> >>  		{ "test_map_unmap", test_map_unmap },
> >>  		{ "test_reprime", test_reprime },
> >>  		{ "test_forked", test_forked },
> >>+		{ "test_correct_cpu_write", test_correct_cpu_write },
> >>+		{ "test_forked_cpu_write", test_forked_cpu_write },
> >>  		{ "test_refcounting", test_refcounting },
> >>  		{ "test_dup", test_dup },
> >>  		{ "test_errors", test_errors },
> >>--
> >>2.1.0
> >>
> >
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch