From: Ben Widawsky Date: Mon, 25 Apr 2011 18:23:07 +0000 (-0700) Subject: drm/i915: reference counted forcewake X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=fcca7926299944841569515da321bef9655b7703;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git drm/i915: reference counted forcewake Provide a reference count to track the forcewake state of the GPU and give a safe mechanism for userspace to wake the GT. This also potentially saves a UC read if the GT is known to be awake already. The reference count is atomic, but the register access and hardware wake sequence is protected by struct_mutex. Signed-off-by: Ben Widawsky Signed-off-by: Chris Wilson --- diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c index 52d2306249cb..3b1147d9023a 100644 --- a/drivers/gpu/drm/i915/i915_debugfs.c +++ b/drivers/gpu/drm/i915/i915_debugfs.c @@ -874,7 +874,7 @@ static int i915_cur_delayinfo(struct seq_file *m, void *unused) int max_freq; /* RPSTAT1 is in the GT power well */ - __gen6_gt_force_wake_get(dev_priv); + gen6_gt_force_wake_get(dev_priv); rpstat = I915_READ(GEN6_RPSTAT1); rpupei = I915_READ(GEN6_RP_CUR_UP_EI); @@ -919,7 +919,7 @@ static int i915_cur_delayinfo(struct seq_file *m, void *unused) seq_printf(m, "Max non-overclocked (RP0) frequency: %dMHz\n", max_freq * 50); - __gen6_gt_force_wake_put(dev_priv); + gen6_gt_force_wake_put(dev_priv); } else { seq_printf(m, "no P-state info available\n"); } diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c index c34a8dd31d02..52e52ce067e1 100644 --- a/drivers/gpu/drm/i915/i915_drv.c +++ b/drivers/gpu/drm/i915/i915_drv.c @@ -263,7 +263,7 @@ void intel_detect_pch (struct drm_device *dev) } } -void __gen6_gt_force_wake_get(struct drm_i915_private *dev_priv) +static void __gen6_gt_force_wake_get(struct drm_i915_private *dev_priv) { int count; @@ -279,12 +279,38 @@ void __gen6_gt_force_wake_get(struct drm_i915_private *dev_priv) udelay(10); } -void __gen6_gt_force_wake_put(struct drm_i915_private *dev_priv) +/* + * Generally this is called implicitly by the register read function. However, + * if some sequence requires the GT to not power down then this function should + * be called at the beginning of the sequence followed by a call to + * gen6_gt_force_wake_put() at the end of the sequence. + */ +void gen6_gt_force_wake_get(struct drm_i915_private *dev_priv) +{ + WARN_ON(!mutex_is_locked(&dev_priv->dev->struct_mutex)); + + /* Forcewake is atomic in case we get in here without the lock */ + if (atomic_add_return(1, &dev_priv->forcewake_count) == 1) + __gen6_gt_force_wake_get(dev_priv); +} + +static void __gen6_gt_force_wake_put(struct drm_i915_private *dev_priv) { I915_WRITE_NOTRACE(FORCEWAKE, 0); POSTING_READ(FORCEWAKE); } +/* + * see gen6_gt_force_wake_get() + */ +void gen6_gt_force_wake_put(struct drm_i915_private *dev_priv) +{ + WARN_ON(!mutex_is_locked(&dev_priv->dev->struct_mutex)); + + if (atomic_dec_and_test(&dev_priv->forcewake_count)) + __gen6_gt_force_wake_put(dev_priv); +} + void __gen6_gt_wait_for_fifo(struct drm_i915_private *dev_priv) { int loop = 500; diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 083644ef8f31..bafb387dd416 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -709,6 +709,8 @@ typedef struct drm_i915_private { struct intel_fbdev *fbdev; struct drm_property *broadcast_rgb_property; + + atomic_t forcewake_count; } drm_i915_private_t; enum i915_cache_level { @@ -1329,8 +1331,8 @@ extern void intel_display_print_error_state(struct seq_file *m, * must be set to prevent GT core from power down and stale values being * returned. */ -void __gen6_gt_force_wake_get(struct drm_i915_private *dev_priv); -void __gen6_gt_force_wake_put(struct drm_i915_private *dev_priv); +void gen6_gt_force_wake_get(struct drm_i915_private *dev_priv); +void gen6_gt_force_wake_put(struct drm_i915_private *dev_priv); void __gen6_gt_wait_for_fifo(struct drm_i915_private *dev_priv); /* We give fast paths for the really cool registers */ @@ -1343,15 +1345,16 @@ void __gen6_gt_wait_for_fifo(struct drm_i915_private *dev_priv); static inline u##x i915_read##x(struct drm_i915_private *dev_priv, u32 reg) { \ u##x val = 0; \ if (NEEDS_FORCE_WAKE((dev_priv), (reg))) { \ - __gen6_gt_force_wake_get(dev_priv); \ + gen6_gt_force_wake_get(dev_priv); \ val = read##y(dev_priv->regs + reg); \ - __gen6_gt_force_wake_put(dev_priv); \ + gen6_gt_force_wake_put(dev_priv); \ } else { \ val = read##y(dev_priv->regs + reg); \ } \ trace_i915_reg_rw(false, reg, val, sizeof(val)); \ return val; \ } + __i915_read(8, b) __i915_read(16, w) __i915_read(32, l) diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index 6225c336de30..edd208e47308 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -396,7 +396,6 @@ static void gen6_pm_irq_handler(struct drm_device *dev) I915_WRITE(GEN6_RP_INTERRUPT_LIMITS, I915_READ(GEN6_RP_INTERRUPT_LIMITS) & ~0x3f0000); } - } gen6_set_rps(dev, new_delay); diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index a38fb3998ad1..220c3e0ea0a6 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -1540,7 +1540,7 @@ static void sandybridge_blit_fbc_update(struct drm_device *dev) u32 blt_ecoskpd; /* Make sure blitter notifies FBC of writes */ - __gen6_gt_force_wake_get(dev_priv); + gen6_gt_force_wake_get(dev_priv); blt_ecoskpd = I915_READ(GEN6_BLITTER_ECOSKPD); blt_ecoskpd |= GEN6_BLITTER_FBC_NOTIFY << GEN6_BLITTER_LOCK_SHIFT; @@ -1551,7 +1551,7 @@ static void sandybridge_blit_fbc_update(struct drm_device *dev) GEN6_BLITTER_LOCK_SHIFT); I915_WRITE(GEN6_BLITTER_ECOSKPD, blt_ecoskpd); POSTING_READ(GEN6_BLITTER_ECOSKPD); - __gen6_gt_force_wake_put(dev_priv); + gen6_gt_force_wake_put(dev_priv); } static void ironlake_enable_fbc(struct drm_crtc *crtc, unsigned long interval) @@ -6973,7 +6973,7 @@ void gen6_enable_rps(struct drm_i915_private *dev_priv) * userspace... */ I915_WRITE(GEN6_RC_STATE, 0); - __gen6_gt_force_wake_get(dev_priv); + gen6_gt_force_wake_get(dev_priv); /* disable the counters and set deterministic thresholds */ I915_WRITE(GEN6_RC_CONTROL, 0); @@ -7074,7 +7074,7 @@ void gen6_enable_rps(struct drm_i915_private *dev_priv) /* enable all PM interrupts */ I915_WRITE(GEN6_PMINTRMSK, 0); - __gen6_gt_force_wake_put(dev_priv); + gen6_gt_force_wake_put(dev_priv); } void intel_enable_clock_gating(struct drm_device *dev)