From 23b2f8bb92feb83127679c53633def32d3108e70 Mon Sep 17 00:00:00 2001 From: Jesse Barnes Date: Tue, 28 Jun 2011 13:04:16 -0700 Subject: drm/i915: load a ring frequency scaling table v3 The ring frequency scaling table tells the PCU to treat certain GPU frequencies as if they were a given CPU frequency for purposes of scaling the ring frequency. Normally the PCU will scale the ring frequency based on the CPU P-state, but with the table present, it will also take the GPU frequency into account. The main downside of keeping the ring frequency high while the CPU is at a low frequency (or asleep altogether) is increased power consumption. But then if you're keeping your GPU busy, you probably want the extra performance. v2: - add units to debug table header (from Eric) - use tsc_khz as a fallback if the cpufreq driver doesn't give us a freq (from Chris) v3: - fix comments & debug output - remove unneeded force wake get/put Reviewed-by: Ben Widawsky Tested-by: Eric Anholt Reviewed-by: Eric Anholt Signed-off-by: Jesse Barnes Signed-off-by: Keith Packard diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c index 4d46441..8a5a032 100644 --- a/drivers/gpu/drm/i915/i915_debugfs.c +++ b/drivers/gpu/drm/i915/i915_debugfs.c @@ -1123,6 +1123,44 @@ static int i915_emon_status(struct seq_file *m, void *unused) return 0; } +static int i915_ring_freq_table(struct seq_file *m, void *unused) +{ + struct drm_info_node *node = (struct drm_info_node *) m->private; + struct drm_device *dev = node->minor->dev; + drm_i915_private_t *dev_priv = dev->dev_private; + int ret; + int gpu_freq, ia_freq; + + if (!IS_GEN6(dev)) { + seq_printf(m, "unsupported on this chipset\n"); + return 0; + } + + ret = mutex_lock_interruptible(&dev->struct_mutex); + if (ret) + return ret; + + seq_printf(m, "GPU freq (MHz)\tEffective CPU freq (MHz)\n"); + + for (gpu_freq = dev_priv->min_delay; gpu_freq <= dev_priv->max_delay; + gpu_freq++) { + I915_WRITE(GEN6_PCODE_DATA, gpu_freq); + I915_WRITE(GEN6_PCODE_MAILBOX, GEN6_PCODE_READY | + GEN6_PCODE_READ_MIN_FREQ_TABLE); + if (wait_for((I915_READ(GEN6_PCODE_MAILBOX) & + GEN6_PCODE_READY) == 0, 10)) { + DRM_ERROR("pcode read of freq table timed out\n"); + continue; + } + ia_freq = I915_READ(GEN6_PCODE_DATA); + seq_printf(m, "%d\t\t%d\n", gpu_freq * 50, ia_freq * 100); + } + + mutex_unlock(&dev->struct_mutex); + + return 0; +} + static int i915_gfxec(struct seq_file *m, void *unused) { struct drm_info_node *node = (struct drm_info_node *) m->private; @@ -1426,6 +1464,7 @@ static struct drm_info_list i915_debugfs_list[] = { {"i915_inttoext_table", i915_inttoext_table, 0}, {"i915_drpc_info", i915_drpc_info, 0}, {"i915_emon_status", i915_emon_status, 0}, + {"i915_ring_freq_table", i915_ring_freq_table, 0}, {"i915_gfxec", i915_gfxec, 0}, {"i915_fbc_status", i915_fbc_status, 0}, {"i915_sr_status", i915_sr_status, 0}, diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index 5d5def7..4a446b1 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -3434,7 +3434,9 @@ #define GEN6_PCODE_MAILBOX 0x138124 #define GEN6_PCODE_READY (1<<31) #define GEN6_READ_OC_PARAMS 0xc -#define GEN6_PCODE_WRITE_MIN_FREQ_TABLE 0x9 +#define GEN6_PCODE_WRITE_MIN_FREQ_TABLE 0x8 +#define GEN6_PCODE_READ_MIN_FREQ_TABLE 0x9 #define GEN6_PCODE_DATA 0x138128 +#define GEN6_PCODE_FREQ_IA_RATIO_SHIFT 8 #endif /* _I915_REG_H_ */ diff --git a/drivers/gpu/drm/i915/i915_suspend.c b/drivers/gpu/drm/i915/i915_suspend.c index e8152d2..6fbd997 100644 --- a/drivers/gpu/drm/i915/i915_suspend.c +++ b/drivers/gpu/drm/i915/i915_suspend.c @@ -875,8 +875,10 @@ int i915_restore_state(struct drm_device *dev) intel_init_emon(dev); } - if (IS_GEN6(dev)) + if (IS_GEN6(dev)) { gen6_enable_rps(dev_priv); + gen6_update_ring_freq(dev_priv); + } /* Cache mode state */ I915_WRITE (CACHE_MODE_0, dev_priv->saveCACHE_MODE_0 | 0xffff0000); diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index e58627f..804ac4d 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -24,6 +24,7 @@ * Eric Anholt */ +#include #include #include #include @@ -7273,6 +7274,59 @@ void gen6_enable_rps(struct drm_i915_private *dev_priv) mutex_unlock(&dev_priv->dev->struct_mutex); } +void gen6_update_ring_freq(struct drm_i915_private *dev_priv) +{ + int min_freq = 15; + int gpu_freq, ia_freq, max_ia_freq; + int scaling_factor = 180; + + max_ia_freq = cpufreq_quick_get_max(0); + /* + * Default to measured freq if none found, PCU will ensure we don't go + * over + */ + if (!max_ia_freq) + max_ia_freq = tsc_khz; + + /* Convert from kHz to MHz */ + max_ia_freq /= 1000; + + mutex_lock(&dev_priv->dev->struct_mutex); + + /* + * For each potential GPU frequency, load a ring frequency we'd like + * to use for memory access. We do this by specifying the IA frequency + * the PCU should use as a reference to determine the ring frequency. + */ + for (gpu_freq = dev_priv->max_delay; gpu_freq >= dev_priv->min_delay; + gpu_freq--) { + int diff = dev_priv->max_delay - gpu_freq; + + /* + * For GPU frequencies less than 750MHz, just use the lowest + * ring freq. + */ + if (gpu_freq < min_freq) + ia_freq = 800; + else + ia_freq = max_ia_freq - ((diff * scaling_factor) / 2); + ia_freq = DIV_ROUND_CLOSEST(ia_freq, 100); + + I915_WRITE(GEN6_PCODE_DATA, + (ia_freq << GEN6_PCODE_FREQ_IA_RATIO_SHIFT) | + gpu_freq); + I915_WRITE(GEN6_PCODE_MAILBOX, GEN6_PCODE_READY | + GEN6_PCODE_WRITE_MIN_FREQ_TABLE); + if (wait_for((I915_READ(GEN6_PCODE_MAILBOX) & + GEN6_PCODE_READY) == 0, 10)) { + DRM_ERROR("pcode write of freq table timed out\n"); + continue; + } + } + + mutex_unlock(&dev_priv->dev->struct_mutex); +} + static void ironlake_init_clock_gating(struct drm_device *dev) { struct drm_i915_private *dev_priv = dev->dev_private; @@ -7916,8 +7970,10 @@ void intel_modeset_init(struct drm_device *dev) intel_init_emon(dev); } - if (IS_GEN6(dev)) + if (IS_GEN6(dev)) { gen6_enable_rps(dev_priv); + gen6_update_ring_freq(dev_priv); + } INIT_WORK(&dev_priv->idle_work, intel_idle_update); setup_timer(&dev_priv->idle_timer, intel_gpu_idle_timer, diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h index 9ffa61e..8ac3bd8 100644 --- a/drivers/gpu/drm/i915/intel_drv.h +++ b/drivers/gpu/drm/i915/intel_drv.h @@ -317,6 +317,7 @@ extern void intel_enable_clock_gating(struct drm_device *dev); extern void ironlake_enable_drps(struct drm_device *dev); extern void ironlake_disable_drps(struct drm_device *dev); extern void gen6_enable_rps(struct drm_i915_private *dev_priv); +extern void gen6_update_ring_freq(struct drm_i915_private *dev_priv); extern void gen6_disable_rps(struct drm_device *dev); extern void intel_init_emon(struct drm_device *dev); -- cgit v0.10.2