[igt-dev] [PATCH i-g-t v4] lib/i915: Add a helper to read mmio registers via ioctl
Kamil Konieczny
kamil.konieczny at linux.intel.com
Fri Sep 15 17:55:58 UTC 2023
Hi Alan,
On 2023-09-14 at 20:29:14 -0700, Alan Previn wrote:
> Add a helper into existing ioctl_wrappers.c to call
> DRM_IOCTL_I915_REG_READ to read whitelisted registers.
>
> v4: - minor nits (Kamil).
> v3: - fix documentation for the new helpers and optimize
> the returning of value for i915_reg_read_ioctl (Kamil).
> v2: - move the new helper into ioctl_wrapper.c/h (Ashutosh)
> - follow the ioctl_wrapper convention where __foo
> is allowed to fail and foo will assert if fails (Kamil).
> - use a #define for the RENDER_RING_TIMESTAMP reg (Kamil).
>
> Signed-off-by: Alan Previn <alan.previn.teres.alexis at intel.com>
> ---
> lib/intel_reg.h | 3 ++
> lib/ioctl_wrappers.c | 49 ++++++++++++++++++++++++++++
> lib/ioctl_wrappers.h | 2 ++
> tests/intel/gem_reg_read.c | 28 ++++------------
> tests/intel/i915_pm_rpm.c | 10 +++---
> tools/i915-perf/i915_perf_recorder.c | 3 +-
> tools/intel_forcewaked.c | 4 ++-
> 7 files changed, 69 insertions(+), 30 deletions(-)
>
> diff --git a/lib/intel_reg.h b/lib/intel_reg.h
> index 3bf3676dc..04ea93eb6 100644
> --- a/lib/intel_reg.h
> +++ b/lib/intel_reg.h
> @@ -689,6 +689,9 @@ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
> #define GEN12_GFX_AUX_TABLE_BASE_ADDR 0x4200
> #define GEN12_VEBOX_AUX_TABLE_BASE_ADDR 0x4230
>
> +/* Command Streamer registers
> + */
> +#define RENDER_RING_TIMESTAMP 0x2358
>
> /* BitBlt Instructions
> *
> diff --git a/lib/ioctl_wrappers.c b/lib/ioctl_wrappers.c
> index 146973f0d..8ce95e915 100644
> --- a/lib/ioctl_wrappers.c
> +++ b/lib/ioctl_wrappers.c
> @@ -887,6 +887,55 @@ bool gem_engine_reset_enabled(int fd)
> return gem_gpu_reset_type(fd) > 1;
> }
>
> +/**
> + * __i915_reg_read_ioctl:
> + * @drmfd: device file descriptor
> + * @offset: mmio register to read from
> + * @value: ptr to fill with results from read
> + *
> + * This function uses DRM_IOCTL_I915_REG_READ to read the
> + * register.
> + *
> + * Return:
> + * 0 if successful, with *value filled
> + * otherwise -errno
> + */
> +int __i915_reg_read_ioctl(int drmfd, __u64 offset, __u64 *value)
> +{
> + struct drm_i915_reg_read reg_read = {0};
> + int ret = 0;
> +
> + reg_read.offset = offset;
> + if (igt_ioctl(drmfd, DRM_IOCTL_I915_REG_READ, ®_read))
> + ret = -errno;
> + else if (value)
> + *value = reg_read.val;
> +
> + return ret;
> +}
> +
> +/**
> + * i915_reg_read_ioctl:
> + * @drmfd: device file descriptor
> + * @offset: mmio register to read from
> + * @value: ptr to fill with results from read
> + *
> + * This function uses DRM_IOCTL_I915_REG_READ to read the
> + * register.
> + *
> + * Return:
> + * Register value.
> + *
> + */
> +__u64 i915_reg_read_ioctl(int drmfd, __u64 offset)
> +{
> + __u64 value;
> +
> + igt_assert_eq(__i915_reg_read_ioctl(drmfd, offset, &value), 0);
> + errno = 0;
--- ^
Delete this, you already checked errno in assert.
Put one empty line before return from function.
Rest looks good.
Regards,
Kamil
> + return value;
> +}
> +
> bool gem_has_llc(int fd)
> {
> int has_llc;
> diff --git a/lib/ioctl_wrappers.h b/lib/ioctl_wrappers.h
> index b7d7c2ad9..409fea370 100644
> --- a/lib/ioctl_wrappers.h
> +++ b/lib/ioctl_wrappers.h
> @@ -79,6 +79,8 @@ void gem_execbuf_wr(int fd, struct drm_i915_gem_execbuffer2 *execbuf);
> int __gem_execbuf_wr(int fd, struct drm_i915_gem_execbuffer2 *execbuf);
> void gem_execbuf(int fd, struct drm_i915_gem_execbuffer2 *execbuf);
> int __gem_execbuf(int fd, struct drm_i915_gem_execbuffer2 *execbuf);
> +int __i915_reg_read_ioctl(int drmfd, __u64 offset, __u64 *value);
> +__u64 i915_reg_read_ioctl(int drmfd, __u64 offset);
>
> #ifndef I915_GEM_DOMAIN_WC
> #define I915_GEM_DOMAIN_WC 0x80
> diff --git a/tests/intel/gem_reg_read.c b/tests/intel/gem_reg_read.c
> index de6788abe..4bf330df6 100644
> --- a/tests/intel/gem_reg_read.c
> +++ b/tests/intel/gem_reg_read.c
> @@ -32,6 +32,8 @@
> #include <sys/utsname.h>
> #include <time.h>
>
> +#include "lib/ioctl_wrappers.h"
> +
> /**
> * TEST: gem reg read
> * Feature: gem_core
> @@ -52,24 +54,6 @@ struct local_drm_i915_reg_read {
> __u64 val; /* Return value */
> };
>
> -#define REG_READ_IOCTL DRM_IOWR(DRM_COMMAND_BASE + 0x31, struct local_drm_i915_reg_read)
> -
> -#define RENDER_RING_TIMESTAMP 0x2358
> -
> -static int read_register(int fd, uint64_t offset, uint64_t * val)
> -{
> - int ret = 0;
> - struct local_drm_i915_reg_read reg_read;
> - reg_read.offset = offset;
> -
> - if (drmIoctl(fd, REG_READ_IOCTL, ®_read))
> - ret = -errno;
> -
> - *val = reg_read.val;
> -
> - return ret;
> -}
> -
> static bool check_kernel_x86_64(void)
> {
> int ret;
> @@ -87,9 +71,9 @@ static bool check_kernel_x86_64(void)
> static bool check_timestamp(int fd)
> {
> int ret;
> - uint64_t val;
> + __u64 val;
>
> - ret = read_register(fd, RENDER_RING_TIMESTAMP | 1, &val);
> + ret = __i915_reg_read_ioctl(fd, RENDER_RING_TIMESTAMP | 1, &val);
>
> return ret == 0;
> }
> @@ -103,7 +87,7 @@ static int timer_query(int fd, uint64_t * val)
> if (has_proper_timestamp)
> offset |= 1;
>
> - ret = read_register(fd, offset, val);
> + ret = __i915_reg_read_ioctl(fd, offset, (__u64 *)val);
>
> /*
> * When reading the timestamp register with single 64b read, we are observing
> @@ -168,7 +152,7 @@ igt_main
> }
>
> igt_subtest("bad-register")
> - igt_assert_eq(read_register(fd, 0x12345678, &val), -EINVAL);
> + igt_assert_eq(__i915_reg_read_ioctl(fd, 0x12345678, (__u64 *)&val), -EINVAL);
>
> igt_subtest("timestamp-moving") {
> igt_skip_on(timer_query(fd, &val) != 0);
> diff --git a/tests/intel/i915_pm_rpm.c b/tests/intel/i915_pm_rpm.c
> index 17413ffe5..f60accd39 100644
> --- a/tests/intel/i915_pm_rpm.c
> +++ b/tests/intel/i915_pm_rpm.c
> @@ -40,6 +40,10 @@
> #include <sys/mman.h>
> #include <sys/types.h>
> #include <sys/stat.h>
> +
> +#include "lib/ioctl_wrappers.h"
> +#include "lib/intel_reg.h"
> +
> /**
> * TEST: i915 pm rpm
> *
> @@ -1852,13 +1856,9 @@ static void gem_evict_pwrite_subtest(void)
> /* This also triggered WARNs on dmesg at some point. */
> static void reg_read_ioctl_subtest(void)
> {
> - struct drm_i915_reg_read rr = {
> - .offset = 0x2358, /* render ring timestamp */
> - };
> -
> disable_all_screens_and_wait(&ms_data);
>
> - do_ioctl(drm_fd, DRM_IOCTL_I915_REG_READ, &rr);
> + i915_reg_read_ioctl(drm_fd, RENDER_RING_TIMESTAMP);
>
> igt_assert(wait_for_suspended());
> }
> diff --git a/tools/i915-perf/i915_perf_recorder.c b/tools/i915-perf/i915_perf_recorder.c
> index ca4354832..1bf1553f4 100644
> --- a/tools/i915-perf/i915_perf_recorder.c
> +++ b/tools/i915-perf/i915_perf_recorder.c
> @@ -52,6 +52,7 @@
> #include "i915/perf_data.h"
>
> #include "i915_perf_recorder_commands.h"
> +#include "lib/intel_reg.h"
>
> #define ALIGN(v, a) (((v) + (a)-1) & ~((a)-1))
> #define ARRAY_SIZE(arr) (sizeof(arr)/sizeof((arr)[0]))
> @@ -623,8 +624,6 @@ get_correlation_timestamps(struct intel_perf_record_timestamp_correlation *corr,
> } attempts[3];
> uint32_t best = 0;
>
> -#define RENDER_RING_TIMESTAMP 0x2358
> -
> reg_read.offset = RENDER_RING_TIMESTAMP | I915_REG_READ_8B_WA;
>
> /* Gather 3 correlations. */
> diff --git a/tools/intel_forcewaked.c b/tools/intel_forcewaked.c
> index 87b26d43a..584358446 100644
> --- a/tools/intel_forcewaked.c
> +++ b/tools/intel_forcewaked.c
> @@ -38,6 +38,8 @@
> #include "intel_chipset.h"
> #include "drmtest.h"
>
> +#include "lib/intel_reg.h"
> +
> bool daemonized;
>
> #define INFO_PRINT(...) \
> @@ -59,7 +61,7 @@ help(char *prog) {
> static int
> is_alive(struct intel_mmio_data *mmio_data) {
> /* Read the timestamp, which should *almost* always be !0 */
> - return (intel_register_read(mmio_data, 0x2358) != 0);
> + return (intel_register_read(mmio_data, RENDER_RING_TIMESTAMP) != 0);
> }
>
> int main(int argc, char *argv[])
>
> base-commit: 099e058c5dfb7a49942edf03cae88a52a77077a3
> --
> 2.39.0
>
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