We currently using GuC as a proxy to the hardware. When Guc is used in such mode, it consumes the bit 20 of the hw_id to indicate that the workload was submitted by proxy.
So far we probably haven't seen the issue because we need to allocate 1048576+ contexts to hit this issue. Still, we should avoid allocating the hw_id on that bit and restriction to bits [0:19] (i.e 20bits instead of 21). v2: Leave the max hw_id computation in i915_gem_context.c (Michel) Signed-off-by: Lionel Landwerlin <[email protected]> BSpec: 1237 --- drivers/gpu/drm/i915/i915_drv.h | 1 + drivers/gpu/drm/i915/i915_gem_context.c | 14 +++++++++++--- drivers/gpu/drm/i915/intel_lrc.c | 2 +- 3 files changed, 13 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 38157df6ff5c..7088a1c3b6ad 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -1841,6 +1841,7 @@ struct drm_i915_private { */ struct ida hw_ida; #define MAX_CONTEXT_HW_ID (1<<21) /* exclusive */ +#define MAX_GUC_CONTEXT_HW_ID (1<<20) /* exclusive */ #define GEN11_MAX_CONTEXT_HW_ID (1<<11) /* exclusive */ } contexts; diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c index 81f086397d10..fa732592e221 100644 --- a/drivers/gpu/drm/i915/i915_gem_context.c +++ b/drivers/gpu/drm/i915/i915_gem_context.c @@ -208,10 +208,18 @@ static int assign_hw_id(struct drm_i915_private *dev_priv, unsigned *out) int ret; unsigned int max; - if (INTEL_GEN(dev_priv) >= 11) + if (INTEL_GEN(dev_priv) >= 11) { max = GEN11_MAX_CONTEXT_HW_ID; - else - max = MAX_CONTEXT_HW_ID; + } else { + /* + * When using GuC in proxy submission, GuC consumes the + * highest bit in the context id to indicate proxy submission. + */ + max = USES_GUC_SUBMISSION(dev_priv) ? + MAX_GUC_CONTEXT_HW_ID : + MAX_CONTEXT_HW_ID; + } + ret = ida_simple_get(&dev_priv->contexts.hw_ida, 0, max, GFP_KERNEL); diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index 517e92c6a70b..d09d2b79552f 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -200,7 +200,7 @@ static inline bool need_preempt(const struct intel_engine_cs *engine, * * bits 0-11: flags, GEN8_CTX_* (cached in ctx->desc_template) * bits 12-31: LRCA, GTT address of (the HWSP of) this context - * bits 32-52: ctx ID, a globally unique tag + * bits 32-52: ctx ID, a globally unique tag (highest bit used by GuC) * bits 53-54: mbz, reserved for use by hardware * bits 55-63: group ID, currently unused and set to 0 * -- 2.17.1 _______________________________________________ Intel-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
