[Beignet] [PATCH] intel: Export pooled EU and min no. of eus in a pool.

[Chris Wilson]

On Wed, Jul 13, 2016 at 11:44:09AM +0100, Arun Siluvery wrote:
> On 06/07/2016 05:51, Yang Rong wrote:
> >Update kernel interface with new I915_GETPARAM ioctl entries for
> >pooled EU and min no. of eus in a pool. Add a wrapping function
> >for each parameter. Userspace drivers need these values when decide
> >the thread count. This kernel enabled pooled eu by default for BXT
> >and for fused down 2x6 parts it is advised to turn it off.
> >
> >But there is another HW issue in these parts (fused
> >down 2x6 parts) before C0 that requires Pooled EU to be enabled as a
> >workaround. In this case the pool configuration changes depending upon
> >which subslice is disabled and the no. of eus in a pool is different,
> >So userspace need to know min no. of eus in a pool.
> >
> >Signed-off-by: Yang Rong <rong.r.yang at intel.com>
> >---
> 
> Could you check this and give comments/ACK to merge this to libdrm?
> Kernel changes are merged in drm-intel.
> 
> regards
> Arun
> 
> >  include/drm/i915_drm.h   |  2 ++
> >  intel/intel_bufmgr.h     |  3 +++
> >  intel/intel_bufmgr_gem.c | 32 ++++++++++++++++++++++++++++++++
> >  3 files changed, 37 insertions(+)
> >
> >diff --git a/include/drm/i915_drm.h b/include/drm/i915_drm.h
> >index c4ce6b2..eb611a7 100644
> >--- a/include/drm/i915_drm.h
> >+++ b/include/drm/i915_drm.h
> >@@ -357,6 +357,8 @@ typedef struct drm_i915_irq_wait {
> >  #define I915_PARAM_HAS_GPU_RESET	 35
> >  #define I915_PARAM_HAS_RESOURCE_STREAMER 36
> >  #define I915_PARAM_HAS_EXEC_SOFTPIN	 37
> >+#define I915_PARAM_HAS_POOLED_EU         38
> >+#define I915_PARAM_MIN_EU_IN_POOL        39
> >
> >  typedef struct drm_i915_getparam {
> >  	__s32 param;
> >diff --git a/intel/intel_bufmgr.h b/intel/intel_bufmgr.h
> >index a1abbcd..8370694 100644
> >--- a/intel/intel_bufmgr.h
> >+++ b/intel/intel_bufmgr.h
> >@@ -273,6 +273,9 @@ int drm_intel_get_reset_stats(drm_intel_context *ctx,
> >  int drm_intel_get_subslice_total(int fd, unsigned int *subslice_total);
> >  int drm_intel_get_eu_total(int fd, unsigned int *eu_total);
> >
> >+int drm_intel_get_pooled_eu(int fd, unsigned int *has_pooled_eu);
> >+int drm_intel_get_min_eu_in_pool(int fd, unsigned int *min_eu);

Do we export more than 2 billion eu? Or more than 2 billion states for
the bool has_pooled_eu?

Could we not just use

int drm_intel_get_pooled_eu(int fd);

ret < 0 => error occurred / unknown
ret == 0 => no
ret > 0 => yes

and same for get_min_eu.

> >+
> >  /** @{ Compatibility defines to keep old code building despite the symbol rename
> >   * from dri_* to drm_intel_*
> >   */
> >diff --git a/intel/intel_bufmgr_gem.c b/intel/intel_bufmgr_gem.c
> >index 0a4012b..b8bb654 100644
> >--- a/intel/intel_bufmgr_gem.c
> >+++ b/intel/intel_bufmgr_gem.c
> >@@ -3237,6 +3237,38 @@ drm_intel_get_eu_total(int fd, unsigned int *eu_total)
> >  	return 0;
> >  }
> >
> >+int
> >+drm_intel_get_pooled_eu(int fd, unsigned int *has_pooled_eu)
> >+{
> >+	drm_i915_getparam_t gp;
> >+	int ret;
> >+
> >+	memclear(gp);
> >+	gp.value = (int*)has_pooled_eu;
> >+	gp.param = I915_PARAM_HAS_POOLED_EU;
> >+	ret = drmIoctl(fd, DRM_IOCTL_I915_GETPARAM, &gp);
> >+	if (ret)

save a few electrons....

int drm_intel_get_pooled_eu(int fd)
{
	drm_i915_getparam_t gp;
	int ret;

	memclear(gp);
	gp.param = I915_PARAM_HAS_POOLED_EU;
	gp.value = &ret;
	if (drmIoctl(fd, DRM_IOCTL_I915_GETPARAM, &gp))
		return -errno;

	return ret;
}

(save a few more by calling this int __getparam(int fd, unsigned name))
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre