[Intel-gfx] [PATCH v2 01/21] drm/i915/gt: Ignore TLB invalidations on idle engines
Andi Shyti
andi.shyti at linux.intel.com
Fri Jul 22 11:56:36 UTC 2022
Hi Mauro,
On Thu, Jul 14, 2022 at 01:06:06PM +0100, Mauro Carvalho Chehab wrote:
> From: Chris Wilson <chris.p.wilson at intel.com>
>
> Check if the device is powered down prior to any engine activity,
> as, on such cases, all the TLBs were already invalidated, so an
> explicit TLB invalidation is not needed, thus reducing the
> performance regression impact due to it.
>
> This becomes more significant with GuC, as it can only do so when
> the connection to the GuC is awake.
>
> Cc: stable at vger.kernel.org
> Fixes: 7938d61591d3 ("drm/i915: Flush TLBs before releasing backing store")
> Signed-off-by: Chris Wilson <chris.p.wilson at intel.com>
> Cc: Fei Yang <fei.yang at intel.com>
> Cc: Andi Shyti <andi.shyti at linux.intel.com>
> Cc: Thomas Hellström <thomas.hellstrom at linux.intel.com>
> Signed-off-by: Mauro Carvalho Chehab <mchehab at kernel.org>
For me it's good, but please, sort out with Tvrtko about his
doubts:
Reviewed-by: Andi Shyti <andi.shyti at linux.intel.com>
Andi
> ---
>
> To avoid mailbombing on a large number of people, only mailing lists were C/C on the cover.
> See [PATCH v2 00/21] at: https://lore.kernel.org/all/cover.1657800199.git.mchehab@kernel.org/
>
> drivers/gpu/drm/i915/gem/i915_gem_pages.c | 10 ++++++----
> drivers/gpu/drm/i915/gt/intel_gt.c | 17 ++++++++++-------
> drivers/gpu/drm/i915/gt/intel_gt_pm.h | 3 +++
> 3 files changed, 19 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_pages.c b/drivers/gpu/drm/i915/gem/i915_gem_pages.c
> index 97c820eee115..6835279943df 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_pages.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_pages.c
> @@ -6,14 +6,15 @@
>
> #include <drm/drm_cache.h>
>
> +#include "gt/intel_gt.h"
> +#include "gt/intel_gt_pm.h"
> +
> #include "i915_drv.h"
> #include "i915_gem_object.h"
> #include "i915_scatterlist.h"
> #include "i915_gem_lmem.h"
> #include "i915_gem_mman.h"
>
> -#include "gt/intel_gt.h"
> -
> void __i915_gem_object_set_pages(struct drm_i915_gem_object *obj,
> struct sg_table *pages,
> unsigned int sg_page_sizes)
> @@ -217,10 +218,11 @@ __i915_gem_object_unset_pages(struct drm_i915_gem_object *obj)
>
> if (test_and_clear_bit(I915_BO_WAS_BOUND_BIT, &obj->flags)) {
> struct drm_i915_private *i915 = to_i915(obj->base.dev);
> + struct intel_gt *gt = to_gt(i915);
> intel_wakeref_t wakeref;
>
> - with_intel_runtime_pm_if_active(&i915->runtime_pm, wakeref)
> - intel_gt_invalidate_tlbs(to_gt(i915));
> + with_intel_gt_pm_if_awake(gt, wakeref)
> + intel_gt_invalidate_tlbs(gt);
> }
>
> return pages;
> diff --git a/drivers/gpu/drm/i915/gt/intel_gt.c b/drivers/gpu/drm/i915/gt/intel_gt.c
> index 68c2b0d8f187..c4d43da84d8e 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gt.c
> +++ b/drivers/gpu/drm/i915/gt/intel_gt.c
> @@ -12,6 +12,7 @@
>
> #include "i915_drv.h"
> #include "intel_context.h"
> +#include "intel_engine_pm.h"
> #include "intel_engine_regs.h"
> #include "intel_ggtt_gmch.h"
> #include "intel_gt.h"
> @@ -924,6 +925,7 @@ void intel_gt_invalidate_tlbs(struct intel_gt *gt)
> struct drm_i915_private *i915 = gt->i915;
> struct intel_uncore *uncore = gt->uncore;
> struct intel_engine_cs *engine;
> + intel_engine_mask_t awake, tmp;
> enum intel_engine_id id;
> const i915_reg_t *regs;
> unsigned int num = 0;
> @@ -947,26 +949,31 @@ void intel_gt_invalidate_tlbs(struct intel_gt *gt)
>
> GEM_TRACE("\n");
>
> - assert_rpm_wakelock_held(&i915->runtime_pm);
> -
> mutex_lock(>->tlb_invalidate_lock);
> intel_uncore_forcewake_get(uncore, FORCEWAKE_ALL);
>
> spin_lock_irq(&uncore->lock); /* serialise invalidate with GT reset */
>
> + awake = 0;
> for_each_engine(engine, gt, id) {
> struct reg_and_bit rb;
>
> + if (!intel_engine_pm_is_awake(engine))
> + continue;
> +
> rb = get_reg_and_bit(engine, regs == gen8_regs, regs, num);
> if (!i915_mmio_reg_offset(rb.reg))
> continue;
>
> intel_uncore_write_fw(uncore, rb.reg, rb.bit);
> + awake |= engine->mask;
> }
>
> spin_unlock_irq(&uncore->lock);
>
> - for_each_engine(engine, gt, id) {
> + for_each_engine_masked(engine, gt, awake, tmp) {
> + struct reg_and_bit rb;
> +
> /*
> * HW architecture suggest typical invalidation time at 40us,
> * with pessimistic cases up to 100us and a recommendation to
> @@ -974,12 +981,8 @@ void intel_gt_invalidate_tlbs(struct intel_gt *gt)
> */
> const unsigned int timeout_us = 100;
> const unsigned int timeout_ms = 4;
> - struct reg_and_bit rb;
>
> rb = get_reg_and_bit(engine, regs == gen8_regs, regs, num);
> - if (!i915_mmio_reg_offset(rb.reg))
> - continue;
> -
> if (__intel_wait_for_register_fw(uncore,
> rb.reg, rb.bit, 0,
> timeout_us, timeout_ms,
> diff --git a/drivers/gpu/drm/i915/gt/intel_gt_pm.h b/drivers/gpu/drm/i915/gt/intel_gt_pm.h
> index bc898df7a48c..a334787a4939 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gt_pm.h
> +++ b/drivers/gpu/drm/i915/gt/intel_gt_pm.h
> @@ -55,6 +55,9 @@ static inline void intel_gt_pm_might_put(struct intel_gt *gt)
> for (tmp = 1, intel_gt_pm_get(gt); tmp; \
> intel_gt_pm_put(gt), tmp = 0)
>
> +#define with_intel_gt_pm_if_awake(gt, wf) \
> + for (wf = intel_gt_pm_get_if_awake(gt); wf; intel_gt_pm_put_async(gt), wf = 0)
> +
> static inline int intel_gt_pm_wait_for_idle(struct intel_gt *gt)
> {
> return intel_wakeref_wait_for_idle(>->wakeref);
> --
> 2.36.1
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