Re: [igt-dev] [i-g-t] lib/ioctl_wrappers: Keep IGT working without pread/pwrite ioctls
From: Dave Airlie <hidden>
Date: 2021-01-11 20:57:58
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@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.
quoted hunk ↗ jump to hunk
Reviewed-by: Zbigniew Kempczyński <redacted> Signed-off-by: Ashutosh Dixit <redacted> --- 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);