[Intel-gfx] [PATCH 07/19] drm/i915/icl: Mind the SFC units when resetting VD or VEBox engines
Tvrtko Ursulin
tvrtko.ursulin at linux.intel.com
Wed Dec 12 14:36:27 UTC 2018
On 12/12/2018 13:41, Chris Wilson wrote:
> From: Oscar Mateo <oscar.mateo at intel.com>
>
> SFC (Scaler & Format Converter) units are shared between VD and VEBoxes.
> They also happen to have separate reset bits. So, whenever we want to reset
> one or more of the media engines, we have to make sure the SFCs do not
> change owner in the process and, if this owner happens to be one of the
> engines being reset, we need to reset the SFC as well.
>
> This happens in 4 steps:
>
> 1) Tell the engine that a software reset is going to happen. The engine
> will then try to force lock the SFC (if currently locked, it will
> remain so; if currently unlocked, it will ignore this and all new lock
> requests).
>
> 2) Poll the ack bit to make sure the hardware has received the forced
> lock from the driver. Once this bit is set, it indicates SFC status
> (lock or unlock) will not change anymore (until we tell the engine it
> is safe to unlock again).
>
> 3) Check the usage bit to see if the SFC has ended up being locked to
> the engine we want to reset. If this is the case, we have to reset
> the SFC as well.
>
> 4) Unlock all the SFCs once the reset sequence is completed.
>
> Obviously, if we are resetting the whole GPU, we don't have to worry
> about all of this.
>
> BSpec: 10989
> BSpec: 10990
> BSpec: 10954
> BSpec: 10955
> BSpec: 10956
> BSpec: 19212
>
> Signed-off-by: Tomasz Lis <tomasz.lis at intel.com>
> Signed-off-by: Oscar Mateo <oscar.mateo at intel.com>
> Signed-off-by: Michel Thierry <michel.thierry at intel.com>
> Cc: Michel Thierry <michel.thierry at intel.com>
> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
> drivers/gpu/drm/i915/i915_reg.h | 18 +++++
> drivers/gpu/drm/i915/intel_uncore.c | 115 ++++++++++++++++++++++++++--
> 2 files changed, 128 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 0a7d60509ca7..0796526dc10f 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -347,6 +347,24 @@ static inline bool i915_mmio_reg_valid(i915_reg_t reg)
> #define GEN11_GRDOM_MEDIA4 (1 << 8)
> #define GEN11_GRDOM_VECS (1 << 13)
> #define GEN11_GRDOM_VECS2 (1 << 14)
> +#define GEN11_GRDOM_SFC0 (1 << 17)
> +#define GEN11_GRDOM_SFC1 (1 << 18)
> +
> +#define GEN11_VCS_SFC_RESET_BIT(instance) (GEN11_GRDOM_SFC0 << ((instance) >> 1))
> +#define GEN11_VECS_SFC_RESET_BIT(instance) (GEN11_GRDOM_SFC0 << (instance))
> +
> +#define GEN11_VCS_SFC_FORCED_LOCK(engine) _MMIO((engine)->mmio_base + 0x88C)
> +#define GEN11_VCS_SFC_FORCED_LOCK_BIT (1 << 0)
> +#define GEN11_VCS_SFC_LOCK_STATUS(engine) _MMIO((engine)->mmio_base + 0x890)
> +#define GEN11_VCS_SFC_USAGE_BIT (1 << 0)
> +#define GEN11_VCS_SFC_LOCK_ACK_BIT (1 << 1)
> +
> +#define GEN11_VECS_SFC_FORCED_LOCK(engine) _MMIO((engine)->mmio_base + 0x201C)
> +#define GEN11_VECS_SFC_FORCED_LOCK_BIT (1 << 0)
> +#define GEN11_VECS_SFC_LOCK_ACK(engine) _MMIO((engine)->mmio_base + 0x2018)
> +#define GEN11_VECS_SFC_LOCK_ACK_BIT (1 << 0)
> +#define GEN11_VECS_SFC_USAGE(engine) _MMIO((engine)->mmio_base + 0x2014)
> +#define GEN11_VECS_SFC_USAGE_BIT (1 << 0)
>
> #define RING_PP_DIR_BASE(engine) _MMIO((engine)->mmio_base + 0x228)
> #define RING_PP_DIR_BASE_READ(engine) _MMIO((engine)->mmio_base + 0x518)
> diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
> index 9289515108c3..408692b88c98 100644
> --- a/drivers/gpu/drm/i915/intel_uncore.c
> +++ b/drivers/gpu/drm/i915/intel_uncore.c
> @@ -1931,6 +1931,103 @@ static int gen6_reset_engines(struct drm_i915_private *dev_priv,
> return gen6_hw_domain_reset(dev_priv, hw_mask);
> }
>
> +static u32 gen11_lock_sfc(struct drm_i915_private *dev_priv,
> + struct intel_engine_cs *engine)
> +{
> + u8 vdbox_sfc_access = INTEL_INFO(dev_priv)->vdbox_sfc_access;
Only a single use site so could get away with a local copy.
> + i915_reg_t sfc_forced_lock, sfc_forced_lock_ack;
> + u32 sfc_forced_lock_bit, sfc_forced_lock_ack_bit;
> + i915_reg_t sfc_usage;
> + u32 sfc_usage_bit;
> + u32 sfc_reset_bit;
> +
> + switch (engine->class) {
> + case VIDEO_DECODE_CLASS:
> + if ((BIT(engine->instance) & vdbox_sfc_access) == 0)
> + return 0;
> +
> + sfc_forced_lock = GEN11_VCS_SFC_FORCED_LOCK(engine);
> + sfc_forced_lock_bit = GEN11_VCS_SFC_FORCED_LOCK_BIT;
> +
> + sfc_forced_lock_ack = GEN11_VCS_SFC_LOCK_STATUS(engine);
> + sfc_forced_lock_ack_bit = GEN11_VCS_SFC_LOCK_ACK_BIT;
> +
> + sfc_usage = GEN11_VCS_SFC_LOCK_STATUS(engine);
> + sfc_usage_bit = GEN11_VCS_SFC_USAGE_BIT;
> + sfc_reset_bit = GEN11_VCS_SFC_RESET_BIT(engine->instance);
> + break;
> +
> + case VIDEO_ENHANCEMENT_CLASS:
> + sfc_forced_lock = GEN11_VECS_SFC_FORCED_LOCK(engine);
> + sfc_forced_lock_bit = GEN11_VECS_SFC_FORCED_LOCK_BIT;
> +
> + sfc_forced_lock_ack = GEN11_VECS_SFC_LOCK_ACK(engine);
> + sfc_forced_lock_ack_bit = GEN11_VECS_SFC_LOCK_ACK_BIT;
> +
> + sfc_usage = GEN11_VECS_SFC_USAGE(engine);
> + sfc_usage_bit = GEN11_VECS_SFC_USAGE_BIT;
> + sfc_reset_bit = GEN11_VECS_SFC_RESET_BIT(engine->instance);
> + break;
> +
> + default:
> + return 0;
> + }
> +
> + /*
> + * Tell the engine that a software reset is going to happen. The engine
> + * will then try to force lock the SFC (if currently locked, it will
> + * remain so until we tell the engine it is safe to unlock; if currently
> + * unlocked, it will ignore this and all new lock requests). If SFC
> + * ends up being locked to the engine we want to reset, we have to reset
> + * it as well (we will unlock it once the reset sequence is completed).
> + */
> + I915_WRITE_FW(sfc_forced_lock,
> + I915_READ_FW(sfc_forced_lock) | sfc_forced_lock_bit);
> +
> + if (__intel_wait_for_register_fw(dev_priv,
> + sfc_forced_lock_ack,
> + sfc_forced_lock_ack_bit,
> + sfc_forced_lock_ack_bit,
> + 1000, 0, NULL)) {
> + DRM_DEBUG_DRIVER("Wait for SFC forced lock ack failed\n");
> + return 0;
> + }
> +
> + if ((I915_READ_FW(sfc_usage) & sfc_usage_bit) == sfc_usage_bit)
"== sfc_usage_bit" parts is redundant.
> + return sfc_reset_bit;
> +
> + return 0;
> +}
> +
> +static void gen11_unlock_sfc(struct drm_i915_private *dev_priv,
> + struct intel_engine_cs *engine)
> +{
> + u8 vdbox_sfc_access = INTEL_INFO(dev_priv)->vdbox_sfc_access;
> + i915_reg_t sfc_forced_lock;
> + u32 sfc_forced_lock_bit;
> +
> + switch (engine->class) {
> + case VIDEO_DECODE_CLASS:
> + if ((BIT(engine->instance) & vdbox_sfc_access) == 0)
> + return;
> +
> + sfc_forced_lock = GEN11_VCS_SFC_FORCED_LOCK(engine);
> + sfc_forced_lock_bit = GEN11_VCS_SFC_FORCED_LOCK_BIT;
> + break;
> +
> + case VIDEO_ENHANCEMENT_CLASS:
> + sfc_forced_lock = GEN11_VECS_SFC_FORCED_LOCK(engine);
> + sfc_forced_lock_bit = GEN11_VECS_SFC_FORCED_LOCK_BIT;
> + break;
> +
> + default:
> + return;
> + }
> +
> + I915_WRITE_FW(sfc_forced_lock,
> + I915_READ_FW(sfc_forced_lock) & ~sfc_forced_lock_bit);
> +}
> +
> /**
> * gen11_reset_engines - reset individual engines
> * @dev_priv: i915 device
> @@ -1947,7 +2044,6 @@ static int gen6_reset_engines(struct drm_i915_private *dev_priv,
> static int gen11_reset_engines(struct drm_i915_private *dev_priv,
> unsigned int engine_mask)
> {
> - struct intel_engine_cs *engine;
> const u32 hw_engine_mask[I915_NUM_ENGINES] = {
> [RCS] = GEN11_GRDOM_RENDER,
> [BCS] = GEN11_GRDOM_BLT,
> @@ -1958,21 +2054,30 @@ static int gen11_reset_engines(struct drm_i915_private *dev_priv,
> [VECS] = GEN11_GRDOM_VECS,
> [VECS2] = GEN11_GRDOM_VECS2,
> };
> + struct intel_engine_cs *engine;
> + unsigned int tmp;
> u32 hw_mask;
> + int ret;
>
> BUILD_BUG_ON(VECS2 + 1 != I915_NUM_ENGINES);
>
> if (engine_mask == ALL_ENGINES) {
> hw_mask = GEN11_GRDOM_FULL;
> } else {
> - unsigned int tmp;
> -
> hw_mask = 0;
> - for_each_engine_masked(engine, dev_priv, engine_mask, tmp)
> + for_each_engine_masked(engine, dev_priv, engine_mask, tmp) {
> hw_mask |= hw_engine_mask[engine->id];
> + hw_mask |= gen11_lock_sfc(dev_priv, engine);
Presumably point No. 3 from the commit message does not mean there is a
separate way to reset the SFC, just that the act of resetting the engine
to which the SFC is locked to, will reset SFC as well?
> + }
> }
>
> - return gen6_hw_domain_reset(dev_priv, hw_mask);
> + ret = gen6_hw_domain_reset(dev_priv, hw_mask);
> +
> + if (engine_mask != ALL_ENGINES)
> + for_each_engine_masked(engine, dev_priv, engine_mask, tmp)
> + gen11_unlock_sfc(dev_priv, engine);
And this presumably means it is okay to unlock engines which we haven't
lock in the previous loop?
> +
> + return ret;
> }
>
> /**
>
I'll go to look for answers to the commit message question before
applying the r-b.
Regards,
Tvrtko
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