From 517aaffe0c1b54b4f732e872a89681c650d3527f Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Tue, 23 Jan 2018 21:04:12 +0000 Subject: [PATCH] drm/i915/execlists: Inhibit context save/restore for the fake preempt context We only use the preempt context to inject an idle point into execlists. We never need to reference its logical state, so tell the GPU never to load it or save it. v2: BIT(2) for save-inhibit. N.B. Daniele mentioned this bit mbz for ICL, and has been moved into the submission process rather than the context image. Suggested-by: Daniele Ceraolo Spurio Signed-off-by: Chris Wilson Cc: Michal Winiarski Cc: Michel Thierry Cc: Michal Wajdeczko Cc: Tvrtko Ursulin Cc: Mika Kuoppala Cc: Daniele Ceraolo Spurio Reviewed-by: Michel Thierry Link: https://patchwork.freedesktop.org/patch/msgid/20180123210412.17653-1-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/intel_lrc.c | 4 ++++ drivers/gpu/drm/i915/intel_lrc.h | 1 + 2 files changed, 5 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index ec3012623697..89e92defbcfe 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -2237,6 +2237,10 @@ populate_lr_context(struct i915_gem_context *ctx, if (!engine->default_state) regs[CTX_CONTEXT_CONTROL + 1] |= _MASKED_BIT_ENABLE(CTX_CTRL_ENGINE_CTX_RESTORE_INHIBIT); + if (ctx->hw_id == PREEMPT_ID) + regs[CTX_CONTEXT_CONTROL + 1] |= + _MASKED_BIT_ENABLE(CTX_CTRL_ENGINE_CTX_RESTORE_INHIBIT | + CTX_CTRL_ENGINE_CTX_SAVE_INHIBIT); i915_gem_object_unpin_map(ctx_obj); diff --git a/drivers/gpu/drm/i915/intel_lrc.h b/drivers/gpu/drm/i915/intel_lrc.h index 6d4f9b995a11..636ced41225d 100644 --- a/drivers/gpu/drm/i915/intel_lrc.h +++ b/drivers/gpu/drm/i915/intel_lrc.h @@ -37,6 +37,7 @@ #define CTX_CTRL_INHIBIT_SYN_CTX_SWITCH (1 << 3) #define CTX_CTRL_ENGINE_CTX_RESTORE_INHIBIT (1 << 0) #define CTX_CTRL_RS_CTX_ENABLE (1 << 1) +#define CTX_CTRL_ENGINE_CTX_SAVE_INHIBIT (1 << 2) #define RING_CONTEXT_STATUS_BUF_BASE(engine) _MMIO((engine)->mmio_base + 0x370) #define RING_CONTEXT_STATUS_BUF_LO(engine, i) _MMIO((engine)->mmio_base + 0x370 + (i) * 8) #define RING_CONTEXT_STATUS_BUF_HI(engine, i) _MMIO((engine)->mmio_base + 0x370 + (i) * 8 + 4) -- 2.30.2