[igt-dev] [i-g-t] lib/ioctl_wrappers: Keep IGT working without pread/pwrite ioctls
Dave Airlie
airlied at linux.ie
Mon Jan 11 20:46:55 UTC 2021
> The general direction at this time is to phase out pread/write ioctls
> and not support them in future products. This means IGT must handle
> the absence of these ioctls. This patch does this by modifying
> gem_read() and gem_write() to do the read/write using the pread/pwrite
> ioctls first but when these ioctls are unavailable fall back to doing
> the read/write using a combination of mmap and memcpy.
>
> Callers who must absolutely use the pread/pwrite ioctls (such as tests
> which test these ioctls or must otherwise only use the pread/pwrite
> ioctls) must use gem_require_pread_pwrite() to skip when these ioctls
> are not available.
>
> v1: Removed __gem_pread, gem_pread, __gem_pwrite and gem_pwrite
> introduced previously since they are not necessary,
> gem_require_pread_pwrite is sufficient
> v2: Fix CI failures in gem_advise and gen9_exec_parse by introducing
> gem_require_pread_pwrite
> v3: Skip mmap for 0 length read/write's
> v4: Remove redundant igt_assert's
> v5: Re-run
> v6: s/EOPNOTSUPP/-EOPNOTSUPP/
There appears to be some push back on landing this,
Acked-by: Dave Airlie <airlied at redhat.com>
If there are testing reasons for keeping pread/pwrite then they should
be done with a test interface via debugfs or hidden behind a big
unstable testing trapdoor, not a uAPI for other userpsace to use.
Dave.
>
> Reviewed-by: Zbigniew Kempczyński <zbigniew.kempczynski at intel.com>
> Signed-off-by: Ashutosh Dixit <ashutosh.dixit at intel.com>
> ---
> lib/ioctl_wrappers.c | 135 +++++++++++++++++++-
> lib/ioctl_wrappers.h | 3 +
> tests/i915/gem_madvise.c | 2 +
> tests/i915/gem_partial_pwrite_pread.c | 1 +
> tests/i915/gem_pread.c | 1 +
> tests/i915/gem_pread_after_blit.c | 1 +
> tests/i915/gem_pwrite.c | 1 +
> tests/i915/gem_pwrite_snooped.c | 1 +
> tests/i915/gem_readwrite.c | 1 +
> tests/i915/gem_set_tiling_vs_pwrite.c | 1 +
> tests/i915/gem_tiled_partial_pwrite_pread.c | 1 +
> tests/i915/gem_tiled_pread_basic.c | 1 +
> tests/i915/gem_tiled_pread_pwrite.c | 1 +
> tests/i915/gem_userptr_blits.c | 2 +
> tests/i915/gen9_exec_parse.c | 4 +-
> 15 files changed, 149 insertions(+), 7 deletions(-)
>
> diff --git a/lib/ioctl_wrappers.c b/lib/ioctl_wrappers.c
> index edac50f0f..ac77b3eb6 100644
> --- a/lib/ioctl_wrappers.c
> +++ b/lib/ioctl_wrappers.c
> @@ -55,6 +55,7 @@
> #include "igt_debugfs.h"
> #include "igt_sysfs.h"
> #include "config.h"
> +#include "i915/gem_mman.h"
>
> #ifdef HAVE_VALGRIND
> #include <valgrind/valgrind.h>
> @@ -323,6 +324,70 @@ void gem_close(int fd, uint32_t handle)
> do_ioctl(fd, DRM_IOCTL_GEM_CLOSE, &close_bo);
> }
>
> +static bool is_cache_coherent(int fd, uint32_t handle)
> +{
> + return gem_get_caching(fd, handle) != I915_CACHING_NONE;
> +}
> +
> +static void mmap_write(int fd, uint32_t handle, uint64_t offset,
> + const void *buf, uint64_t length)
> +{
> + void *map = NULL;
> +
> + if (!length)
> + return;
> +
> + if (is_cache_coherent(fd, handle)) {
> + /* offset arg for mmap functions must be 0 */
> + map = __gem_mmap__cpu_coherent(fd, handle, 0, offset + length,
> + PROT_READ | PROT_WRITE);
> + if (map)
> + gem_set_domain(fd, handle,
> + I915_GEM_DOMAIN_CPU, I915_GEM_DOMAIN_CPU);
> + }
> +
> + if (!map) {
> + map = __gem_mmap_offset__wc(fd, handle, 0, offset + length,
> + PROT_READ | PROT_WRITE);
> + if (!map)
> + map = gem_mmap__wc(fd, handle, 0, offset + length,
> + PROT_READ | PROT_WRITE);
> + gem_set_domain(fd, handle,
> + I915_GEM_DOMAIN_WC, I915_GEM_DOMAIN_WC);
> + }
> +
> + memcpy(map + offset, buf, length);
> + munmap(map, offset + length);
> +}
> +
> +static void mmap_read(int fd, uint32_t handle, uint64_t offset, void *buf, uint64_t length)
> +{
> + void *map = NULL;
> +
> + if (!length)
> + return;
> +
> + if (gem_has_llc(fd) || is_cache_coherent(fd, handle)) {
> + /* offset arg for mmap functions must be 0 */
> + map = __gem_mmap__cpu_coherent(fd, handle, 0,
> + offset + length, PROT_READ);
> + if (map)
> + gem_set_domain(fd, handle, I915_GEM_DOMAIN_CPU, 0);
> + }
> +
> + if (!map) {
> + map = __gem_mmap_offset__wc(fd, handle, 0, offset + length,
> + PROT_READ);
> + if (!map)
> + map = gem_mmap__wc(fd, handle, 0, offset + length,
> + PROT_READ);
> + gem_set_domain(fd, handle, I915_GEM_DOMAIN_WC, 0);
> + }
> +
> + memcpy(buf, map + offset, length);
> + munmap(map, offset + length);
> +}
> +
> int __gem_write(int fd, uint32_t handle, uint64_t offset, const void *buf, uint64_t length)
> {
> struct drm_i915_gem_pwrite gem_pwrite;
> @@ -348,12 +413,18 @@ int __gem_write(int fd, uint32_t handle, uint64_t offset, const void *buf, uint6
> * @buf: pointer to the data to write into the buffer
> * @length: size of the subrange
> *
> - * This wraps the PWRITE ioctl, which is to upload a linear data to a subrange
> - * of a gem buffer object.
> + * Method to write to a gem object. Uses the PWRITE ioctl when it is
> + * available, else it uses mmap + memcpy to upload linear data to a
> + * subrange of a gem buffer object.
> */
> void gem_write(int fd, uint32_t handle, uint64_t offset, const void *buf, uint64_t length)
> {
> - igt_assert_eq(__gem_write(fd, handle, offset, buf, length), 0);
> + int ret = __gem_write(fd, handle, offset, buf, length);
> +
> + igt_assert(ret == 0 || ret == -EOPNOTSUPP);
> +
> + if (ret == -EOPNOTSUPP)
> + mmap_write(fd, handle, offset, buf, length);
> }
>
> int __gem_read(int fd, uint32_t handle, uint64_t offset, void *buf, uint64_t length)
> @@ -380,12 +451,64 @@ int __gem_read(int fd, uint32_t handle, uint64_t offset, void *buf, uint64_t len
> * @buf: pointer to the data to read into
> * @length: size of the subrange
> *
> - * This wraps the PREAD ioctl, which is to download a linear data to a subrange
> - * of a gem buffer object.
> + * Method to read from a gem object. Uses the PREAD ioctl when it is
> + * available, else it uses mmap + memcpy to download linear data from a
> + * subrange of a gem buffer object.
> */
> void gem_read(int fd, uint32_t handle, uint64_t offset, void *buf, uint64_t length)
> {
> - igt_assert_eq(__gem_read(fd, handle, offset, buf, length), 0);
> + int ret = __gem_read(fd, handle, offset, buf, length);
> +
> + igt_assert(ret == 0 || ret == -EOPNOTSUPP);
> +
> + if (ret == -EOPNOTSUPP)
> + mmap_read(fd, handle, offset, buf, length);
> +}
> +
> +/**
> + * gem_has_pwrite
> + * @fd: open i915 drm file descriptor
> + *
> + * Feature test macro to query whether pwrite ioctl is supported
> + */
> +bool gem_has_pwrite(int fd)
> +{
> + uint32_t handle = gem_create(fd, 4096);
> + int buf, ret;
> +
> + ret = __gem_write(fd, handle, 0, &buf, sizeof(buf));
> + gem_close(fd, handle);
> +
> + return ret != -EOPNOTSUPP;
> +}
> +
> +/**
> + * gem_has_pread
> + * @fd: open i915 drm file descriptor
> + *
> + * Feature test macro to query whether pread ioctl is supported
> + */
> +bool gem_has_pread(int fd)
> +{
> + uint32_t handle = gem_create(fd, 4096);
> + int buf, ret;
> +
> + ret = __gem_read(fd, handle, 0, &buf, sizeof(buf));
> + gem_close(fd, handle);
> +
> + return ret != -EOPNOTSUPP;
> +}
> +
> +/**
> + * gem_require_pread_pwrite
> + * @fd: open i915 drm file descriptor
> + *
> + * Feature test macro to query whether pread/pwrite ioctls are supported
> + * and skip if they are not
> + */
> +void gem_require_pread_pwrite(int fd)
> +{
> + igt_require(gem_has_pread(fd) && gem_has_pwrite(fd));
> }
>
> int __gem_set_domain(int fd, uint32_t handle, uint32_t read, uint32_t write)
> diff --git a/lib/ioctl_wrappers.h b/lib/ioctl_wrappers.h
> index b76bea564..81166000a 100644
> --- a/lib/ioctl_wrappers.h
> +++ b/lib/ioctl_wrappers.h
> @@ -71,6 +71,9 @@ int __gem_write(int fd, uint32_t handle, uint64_t offset, const void *buf, uint6
> void gem_write(int fd, uint32_t handle, uint64_t offset, const void *buf, uint64_t length);
> int __gem_read(int fd, uint32_t handle, uint64_t offset, void *buf, uint64_t length);
> void gem_read(int fd, uint32_t handle, uint64_t offset, void *buf, uint64_t length);
> +bool gem_has_pwrite(int fd);
> +bool gem_has_pread(int fd);
> +void gem_require_pread_pwrite(int fd);
> int __gem_set_domain(int fd, uint32_t handle, uint32_t read, uint32_t write);
> void gem_set_domain(int fd, uint32_t handle, uint32_t read, uint32_t write);
> int gem_wait(int fd, uint32_t handle, int64_t *timeout_ns);
> diff --git a/tests/i915/gem_madvise.c b/tests/i915/gem_madvise.c
> index 54c9befff..92e1c5192 100644
> --- a/tests/i915/gem_madvise.c
> +++ b/tests/i915/gem_madvise.c
> @@ -154,6 +154,7 @@ dontneed_before_pwrite(void)
> uint32_t bbe = MI_BATCH_BUFFER_END;
> uint32_t handle;
>
> + gem_require_pread_pwrite(fd);
> handle = gem_create(fd, OBJECT_SIZE);
> gem_madvise(fd, handle, I915_MADV_DONTNEED);
>
> @@ -170,6 +171,7 @@ dontneed_before_exec(void)
> struct drm_i915_gem_exec_object2 exec;
> uint32_t buf[] = { MI_BATCH_BUFFER_END, 0 };
>
> + gem_require_pread_pwrite(fd);
> memset(&execbuf, 0, sizeof(execbuf));
> memset(&exec, 0, sizeof(exec));
>
> diff --git a/tests/i915/gem_partial_pwrite_pread.c b/tests/i915/gem_partial_pwrite_pread.c
> index b10284721..fd7b19f31 100644
> --- a/tests/i915/gem_partial_pwrite_pread.c
> +++ b/tests/i915/gem_partial_pwrite_pread.c
> @@ -281,6 +281,7 @@ igt_main
> data.drm_fd = drm_open_driver(DRIVER_INTEL);
> igt_require_gem(data.drm_fd);
> gem_require_blitter(data.drm_fd);
> + gem_require_pread_pwrite(data.drm_fd);
>
> data.devid = intel_get_drm_devid(data.drm_fd);
> data.bops = buf_ops_create(data.drm_fd);
> diff --git a/tests/i915/gem_pread.c b/tests/i915/gem_pread.c
> index 6d12b8e9f..db1eacedc 100644
> --- a/tests/i915/gem_pread.c
> +++ b/tests/i915/gem_pread.c
> @@ -149,6 +149,7 @@ igt_main_args("s:", NULL, help_str, opt_handler, NULL)
>
> igt_fixture {
> fd = drm_open_driver(DRIVER_INTEL);
> + gem_require_pread_pwrite(fd);
>
> dst = gem_create(fd, object_size);
> src = malloc(object_size);
> diff --git a/tests/i915/gem_pread_after_blit.c b/tests/i915/gem_pread_after_blit.c
> index 81454c930..5c99d0887 100644
> --- a/tests/i915/gem_pread_after_blit.c
> +++ b/tests/i915/gem_pread_after_blit.c
> @@ -212,6 +212,7 @@ igt_main
> igt_fixture {
> fd = drm_open_driver(DRIVER_INTEL);
> igt_require_gem(fd);
> + gem_require_pread_pwrite(fd);
>
> bufmgr = drm_intel_bufmgr_gem_init(fd, 4096);
> drm_intel_bufmgr_gem_enable_reuse(bufmgr);
> diff --git a/tests/i915/gem_pwrite.c b/tests/i915/gem_pwrite.c
> index e491263fd..eea51f978 100644
> --- a/tests/i915/gem_pwrite.c
> +++ b/tests/i915/gem_pwrite.c
> @@ -317,6 +317,7 @@ igt_main_args("s:", NULL, help_str, opt_handler, NULL)
>
> igt_fixture {
> fd = drm_open_driver(DRIVER_INTEL);
> + gem_require_pread_pwrite(fd);
>
> dst = gem_create(fd, object_size);
> src = malloc(object_size);
> diff --git a/tests/i915/gem_pwrite_snooped.c b/tests/i915/gem_pwrite_snooped.c
> index 4a3395241..a2eca6afc 100644
> --- a/tests/i915/gem_pwrite_snooped.c
> +++ b/tests/i915/gem_pwrite_snooped.c
> @@ -132,6 +132,7 @@ igt_simple_main
> fd = drm_open_driver(DRIVER_INTEL);
> igt_require_gem(fd);
> gem_require_blitter(fd);
> + gem_require_pread_pwrite(fd);
>
> devid = intel_get_drm_devid(fd);
> bufmgr = drm_intel_bufmgr_gem_init(fd, 4096);
> diff --git a/tests/i915/gem_readwrite.c b/tests/i915/gem_readwrite.c
> index 6b2977c1c..ca31741c6 100644
> --- a/tests/i915/gem_readwrite.c
> +++ b/tests/i915/gem_readwrite.c
> @@ -83,6 +83,7 @@ igt_main
>
> igt_fixture {
> fd = drm_open_driver(DRIVER_INTEL);
> + gem_require_pread_pwrite(fd);
>
> handle = gem_create(fd, OBJECT_SIZE);
> }
> diff --git a/tests/i915/gem_set_tiling_vs_pwrite.c b/tests/i915/gem_set_tiling_vs_pwrite.c
> index 302ea24b6..8f38c9b9b 100644
> --- a/tests/i915/gem_set_tiling_vs_pwrite.c
> +++ b/tests/i915/gem_set_tiling_vs_pwrite.c
> @@ -55,6 +55,7 @@ igt_simple_main
>
> fd = drm_open_driver(DRIVER_INTEL);
> igt_require(gem_available_fences(fd) > 0);
> + gem_require_pread_pwrite(fd);
>
> for (int i = 0; i < OBJECT_SIZE/4; i++)
> data[i] = i;
> diff --git a/tests/i915/gem_tiled_partial_pwrite_pread.c b/tests/i915/gem_tiled_partial_pwrite_pread.c
> index 7de5358b2..0c4545990 100644
> --- a/tests/i915/gem_tiled_partial_pwrite_pread.c
> +++ b/tests/i915/gem_tiled_partial_pwrite_pread.c
> @@ -270,6 +270,7 @@ igt_main
> igt_require_gem(fd);
> gem_require_mappable_ggtt(fd);
> gem_require_blitter(fd);
> + gem_require_pread_pwrite(fd);
>
> bufmgr = drm_intel_bufmgr_gem_init(fd, 4096);
> //drm_intel_bufmgr_gem_enable_reuse(bufmgr);
> diff --git a/tests/i915/gem_tiled_pread_basic.c b/tests/i915/gem_tiled_pread_basic.c
> index 7cb644104..f8f73c03a 100644
> --- a/tests/i915/gem_tiled_pread_basic.c
> +++ b/tests/i915/gem_tiled_pread_basic.c
> @@ -127,6 +127,7 @@ igt_simple_main
> igt_require(gem_available_fences(fd) > 0);
> handle = create_bo(fd);
> igt_require(gem_get_tiling(fd, handle, &tiling, &swizzle));
> + gem_require_pread_pwrite(fd);
>
> devid = intel_get_drm_devid(fd);
>
> diff --git a/tests/i915/gem_tiled_pread_pwrite.c b/tests/i915/gem_tiled_pread_pwrite.c
> index f58048faa..28490840f 100644
> --- a/tests/i915/gem_tiled_pread_pwrite.c
> +++ b/tests/i915/gem_tiled_pread_pwrite.c
> @@ -114,6 +114,7 @@ igt_simple_main
>
> fd = drm_open_driver(DRIVER_INTEL);
> igt_require(gem_available_fences(fd) > 0);
> + gem_require_pread_pwrite(fd);
>
> count = gem_available_fences(fd) + 1;
> intel_require_memory(2 * count, sizeof(linear), CHECK_RAM);
> diff --git a/tests/i915/gem_userptr_blits.c b/tests/i915/gem_userptr_blits.c
> index 268423dcd..0ccfdbd9c 100644
> --- a/tests/i915/gem_userptr_blits.c
> +++ b/tests/i915/gem_userptr_blits.c
> @@ -890,6 +890,7 @@ static int test_forbidden_ops(int fd)
> uint32_t handle;
> void *ptr;
>
> + gem_require_pread_pwrite(fd);
> igt_assert(posix_memalign(&ptr, PAGE_SIZE, PAGE_SIZE) == 0);
> gem_userptr(fd, ptr, PAGE_SIZE, 0, userptr_flags, &handle);
>
> @@ -1416,6 +1417,7 @@ static void test_readonly_pwrite(int i915)
> */
>
> igt_require(igt_setup_clflush());
> + gem_require_pread_pwrite(i915);
>
> sz = 16 << 12;
> pages = mmap(NULL, sz, PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0);
> diff --git a/tests/i915/gen9_exec_parse.c b/tests/i915/gen9_exec_parse.c
> index 7ddb5bf2b..cfb6de080 100644
> --- a/tests/i915/gen9_exec_parse.c
> +++ b/tests/i915/gen9_exec_parse.c
> @@ -1104,8 +1104,10 @@ igt_main
> -EINVAL);
> }
>
> - igt_subtest("batch-invalid-length")
> + igt_subtest("batch-invalid-length") {
> + gem_require_pread_pwrite(i915);
> test_invalid_length(i915, handle);
> + }
>
> igt_subtest("basic-rejected")
> test_rejected(i915, handle, false);
>
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