[Intel-gfx] [PATCH 3/4] drm/i915: HSW GT3 Slices: exec flag to warn kernel that userspace is using predication
Rodrigo Vivi
rodrigo.vivi at gmail.com
Tue Nov 5 23:44:15 CET 2013
If Userspace isn't using MI_PREDICATE all slices must be enabled for
backward compatibility.
If I915_EXEC_USE_PREDICATE isn't set and defaul is set to half, kernel will force
all slices on.
v2: fix the inverted logic for backwards compatibility
USE_PREDICATE unset force gt_full when defaul is half
instead of GT_FULL flag.
v3: Accepting Chris's suggestions: better variable names;
better logic around state_default x legacy_userspace_busy;
remove unecessary mutex;
v4: Accepting more suggestions from Chris:
* Send all LRIs in only one block and don't ignore if it fails.
* function name and cleaner code on forcing_full.
v5: fix mutex_lock use by Chris.
v6: change state machine logic to fix locks and use number of slices on (1,2) instead of 0
for half and 1 for full.
Init gt slices out of init_hw to avoid reseting values during execution.
CC: Chris Wilson <chris at chris-wilson.co.uk>
CC: Eric Anholt <eric at anholt.net>
CC: Kenneth Graunke <kenneth at whitecape.org>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi at gmail.com>
---
drivers/gpu/drm/i915/i915_drv.h | 14 ++++++
drivers/gpu/drm/i915/i915_gem.c | 4 +-
drivers/gpu/drm/i915/i915_gem_execbuffer.c | 68 ++++++++++++++++++++++++++++++
drivers/gpu/drm/i915/i915_reg.h | 11 +++++
drivers/gpu/drm/i915/intel_display.c | 7 +++
drivers/gpu/drm/i915/intel_drv.h | 1 +
drivers/gpu/drm/i915/intel_pm.c | 63 ++++++++++++++++++++++++---
include/uapi/drm/i915_drm.h | 8 +++-
8 files changed, 167 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 5bd8d6f..74284e6 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1272,6 +1272,18 @@ struct intel_pipe_crc {
wait_queue_head_t wq;
};
+enum gt_slices_state {
+ LEGACY_BUSY = 0,
+ ONE_SLICE,
+ TWO_SLICES,
+};
+
+struct i915_gt_slices {
+ u32 predicate_result_2; /* avoid reads and minimize mutex on execbuf */
+ enum gt_slices_state state;
+ struct mutex lock; /* locks access to slices state and registers */
+};
+
typedef struct drm_i915_private {
struct drm_device *dev;
struct kmem_cache *slab;
@@ -1474,6 +1486,8 @@ typedef struct drm_i915_private {
struct i915_package_c8 pc8;
+ struct i915_gt_slices gt_slices;
+
/* Old dri1 support infrastructure, beware the dragons ya fools entering
* here! */
struct i915_dri1_state dri1;
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index f9c32d1..cfb0687 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -4439,8 +4439,6 @@ i915_gem_init_hw(struct drm_device *dev)
if (dev_priv->ellc_size)
I915_WRITE(HSW_IDICR, I915_READ(HSW_IDICR) | IDIHASHMSK(0xf));
- intel_init_gt_slices(dev);
-
if (HAS_PCH_NOP(dev)) {
u32 temp = I915_READ(GEN7_MSG_CTL);
temp &= ~(WAIT_FOR_PCH_FLR_ACK | WAIT_FOR_PCH_RESET_ACK);
@@ -4495,6 +4493,8 @@ int i915_gem_init(struct drm_device *dev)
return ret;
}
+ intel_init_gt_slices(dev);
+
/* Allow hardware batchbuffers unless told otherwise, but not for KMS. */
if (!drm_core_check_feature(dev, DRIVER_MODESET))
dev_priv->dri1.allow_batchbuffer = 1;
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 0ce0d47..4911690 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -922,6 +922,62 @@ i915_reset_gen7_sol_offsets(struct drm_device *dev,
return 0;
}
+static int gt_legacy_userspace_busy(struct intel_ring_buffer *ring)
+{
+ drm_i915_private_t *dev_priv = ring->dev->dev_private;
+ int ret;
+
+ ret = intel_ring_begin(ring, 18);
+ if (ret)
+ return ret;
+
+ intel_ring_emit(ring, MI_LOAD_REGISTER_IMM(1));
+ intel_ring_emit(ring, HSW_GT_SLICE_INFO);
+ intel_ring_emit(ring, SLICE_SEL_BOTH);
+
+ intel_ring_emit(ring, MI_LOAD_REGISTER_IMM(1));
+ intel_ring_emit(ring, MI_PREDICATE_RESULT_2);
+ intel_ring_emit(ring, LOWER_SLICE_ENABLED);
+ dev_priv->gt_slices.predicate_result_2 = LOWER_SLICE_ENABLED;
+
+ intel_ring_emit(ring, MI_LOAD_REGISTER_IMM(1));
+ intel_ring_emit(ring, HSW_SLICESHUTDOWN);
+ intel_ring_emit(ring, ~SLICE_SHUTDOWN);
+
+ intel_ring_emit(ring, MI_LOAD_REGISTER_IMM(1));
+ intel_ring_emit(ring, RC_IDLE_MAX_COUNT);
+ intel_ring_emit(ring, CS_IDLE_COUNT_1US);
+
+ intel_ring_emit(ring, MI_LOAD_REGISTER_IMM(1));
+ intel_ring_emit(ring, WAIT_FOR_RC6_EXIT);
+ intel_ring_emit(ring, _MASKED_BIT_ENABLE(WAIT_RC6_EXIT));
+
+ intel_ring_emit(ring, MI_LOAD_REGISTER_IMM(1));
+ intel_ring_emit(ring, RC_IDLE_MAX_COUNT);
+ intel_ring_emit(ring, CS_IDLE_COUNT_5US);
+
+ intel_ring_advance(ring);
+
+ return 0;
+}
+
+static bool gt_legacy_userspace(struct intel_ring_buffer *ring,
+ struct drm_i915_gem_execbuffer2 *args)
+{
+ drm_i915_private_t *dev_priv = ring->dev->dev_private;
+
+ if (ring->id == BCS)
+ return false;
+
+ if (!HAS_SLICE_SHUTDOWN(ring->dev))
+ return false;
+
+ if (dev_priv->gt_slices.predicate_result_2 == LOWER_SLICE_ENABLED)
+ return false;
+
+ return (args->flags & I915_EXEC_USE_PREDICATE) == 0;
+}
+
static int
i915_gem_do_execbuffer(struct drm_device *dev, void *data,
struct drm_file *file,
@@ -999,6 +1055,18 @@ i915_gem_do_execbuffer(struct drm_device *dev, void *data,
return -EINVAL;
}
+ if (gt_legacy_userspace(ring, args)) {
+ mutex_lock(&dev_priv->gt_slices.lock);
+ if (dev_priv->gt_slices.state == ONE_SLICE) {
+ ret = gt_legacy_userspace_busy(ring);
+ if (ret == 0)
+ dev_priv->gt_slices.state = LEGACY_BUSY;
+ }
+ mutex_unlock(&dev_priv->gt_slices.lock);
+ if (ret)
+ return ret;
+ }
+
mode = args->flags & I915_EXEC_CONSTANTS_MASK;
mask = I915_EXEC_CONSTANTS_MASK;
switch (mode) {
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index a2e7deb..4617880 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -278,6 +278,17 @@
#define SLICE_STATUS_MAIN_ON (2<<0)
#define SLICE_STATUS_BOTH_ON (3<<0)
+#define HSW_SLICESHUTDOWN 0xA190
+#define SLICE_SHUTDOWN (1<<0)
+
+#define RC_IDLE_MAX_COUNT 0x2054
+#define CS_IDLE_COUNT_1US (1<<1)
+#define CS_IDLE_COUNT_5US (1<<3)
+
+#define WAIT_FOR_RC6_EXIT 0x20CC
+#define WAIT_RC6_EXIT (1<<0)
+#define MASK_WAIT_RC6_EXIT (1<<16)
+
/*
* 3D instructions used by the kernel
*/
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index f34252d..55f2a6e 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -7878,6 +7878,13 @@ void intel_mark_idle(struct drm_device *dev)
if (dev_priv->info->gen >= 6)
gen6_rps_idle(dev->dev_private);
+
+ mutex_lock(&dev_priv->gt_slices.lock);
+ if (dev_priv->gt_slices.state == LEGACY_BUSY) {
+ dev_priv->gt_slices.state = ONE_SLICE;
+ intel_set_gt_half_async(dev);
+ }
+ mutex_unlock(&dev_priv->gt_slices.lock);
}
void intel_mark_fb_busy(struct drm_i915_gem_object *obj,
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index cf37741..deb9464 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -837,6 +837,7 @@ void intel_enable_gt_powersave(struct drm_device *dev);
void intel_disable_gt_powersave(struct drm_device *dev);
void ironlake_teardown_rc6(struct drm_device *dev);
int intel_set_gt_slices(struct drm_device *dev, int slices);
+void intel_set_gt_half_async(struct drm_device *dev);
void intel_init_gt_slices(struct drm_device *dev);
void gen6_update_ring_freq(struct drm_device *dev);
void gen6_rps_idle(struct drm_i915_private *dev_priv);
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 40ab76a..643ab05 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3877,18 +3877,22 @@ static int intel_set_gt_full(struct drm_device *dev)
/* Slices are enabled on RC6 exit */
gen6_gt_force_wake_get(dev_priv);
-
if (wait_for(((I915_READ(HSW_GT_SLICE_INFO) & SLICE_STATUS_MASK) ==
SLICE_STATUS_BOTH_ON), 2000)) {
DRM_ERROR("Timeout enabling full gt slices\n");
+
I915_WRITE(HSW_GT_SLICE_INFO, ~SLICE_SEL_BOTH);
I915_WRITE(MI_PREDICATE_RESULT_2, LOWER_SLICE_DISABLED);
+ dev_priv->gt_slices.predicate_result_2 = LOWER_SLICE_DISABLED;
+
gen6_gt_force_wake_put(dev_priv);
return -ETIMEDOUT;
}
+
I915_WRITE(MI_PREDICATE_RESULT_2, LOWER_SLICE_ENABLED);
- gen6_gt_force_wake_put(dev_priv);
+ dev_priv->gt_slices.predicate_result_2 = LOWER_SLICE_ENABLED;
+ gen6_gt_force_wake_put(dev_priv);
return 0;
}
@@ -3904,28 +3908,71 @@ static int intel_set_gt_half(struct drm_device *dev)
if (wait_for(((I915_READ(HSW_GT_SLICE_INFO) & SLICE_STATUS_MASK) ==
SLICE_STATUS_MAIN_ON), 2000)) {
DRM_ERROR("Timed out disabling half gt slices\n");
+
I915_WRITE(HSW_GT_SLICE_INFO, SLICE_SEL_BOTH);
I915_WRITE(MI_PREDICATE_RESULT_2, LOWER_SLICE_ENABLED);
+ dev_priv->gt_slices.predicate_result_2 = LOWER_SLICE_ENABLED;
+
gen6_gt_force_wake_put(dev_priv);
return -ETIMEDOUT;
}
+
I915_WRITE(MI_PREDICATE_RESULT_2, LOWER_SLICE_DISABLED);
+ dev_priv->gt_slices.predicate_result_2 = LOWER_SLICE_DISABLED;
+
gen6_gt_force_wake_put(dev_priv);
return 0;
}
int intel_set_gt_slices(struct drm_device *dev, int slices)
{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ int ret = 0;
+
if (!HAS_SLICE_SHUTDOWN(dev))
return -ENODEV;
switch (slices) {
- case 1: return intel_set_gt_half(dev);
- case 2: return intel_set_gt_full(dev);
+ case 1:
+ mutex_lock(&dev_priv->gt_slices.lock);
+ if (dev_priv->gt_slices.state == TWO_SLICES) {
+ ret = intel_set_gt_half(dev);
+ if (ret == 0)
+ dev_priv->gt_slices.state = ONE_SLICE;
+ }
+ mutex_unlock(&dev_priv->gt_slices.lock);
+ return ret;
+ case 2:
+ mutex_lock(&dev_priv->gt_slices.lock);
+ if (dev_priv->gt_slices.state == ONE_SLICE) {
+ ret = intel_set_gt_full(dev);
+ if (ret == 0)
+ dev_priv->gt_slices.state = TWO_SLICES;
+ } else if (dev_priv->gt_slices.state == LEGACY_BUSY)
+ dev_priv->gt_slices.state = TWO_SLICES;
+ mutex_unlock(&dev_priv->gt_slices.lock);
+ return ret;
default: return -EINVAL;
}
}
+/**
+ * On Haswell, slices on/off transitions are done via RC6 sequence.
+ * This async function allows you to request slices shutdown without waiting.
+ * Slices will be disabled on next RC6 exit.
+ */
+void intel_set_gt_half_async(struct drm_device *dev)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+
+ if (!HAS_SLICE_SHUTDOWN(dev))
+ return;
+
+ I915_WRITE(HSW_GT_SLICE_INFO, ~SLICE_SEL_BOTH);
+ I915_WRITE(MI_PREDICATE_RESULT_2, LOWER_SLICE_DISABLED);
+ dev_priv->gt_slices.predicate_result_2 = LOWER_SLICE_DISABLED;
+}
+
void intel_init_gt_slices(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
@@ -3936,9 +3983,13 @@ void intel_init_gt_slices(struct drm_device *dev)
if (!HAS_SLICE_SHUTDOWN(dev))
return;
+ dev_priv->gt_slices.state = TWO_SLICES;
+ dev_priv->gt_slices.predicate_result_2 = LOWER_SLICE_ENABLED;
+ mutex_init(&dev_priv->gt_slices.lock);
+
if (i915_gt_slices == 1) {
- I915_WRITE(HSW_GT_SLICE_INFO, ~SLICE_SEL_BOTH);
- I915_WRITE(MI_PREDICATE_RESULT_2, LOWER_SLICE_DISABLED);
+ intel_set_gt_half_async(dev);
+ dev_priv->gt_slices.state = ONE_SLICE;
return;
}
diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
index 3a4e97b..3fa3e24 100644
--- a/include/uapi/drm/i915_drm.h
+++ b/include/uapi/drm/i915_drm.h
@@ -731,7 +731,13 @@ struct drm_i915_gem_execbuffer2 {
*/
#define I915_EXEC_HANDLE_LUT (1<<12)
-#define __I915_EXEC_UNKNOWN_FLAGS -(I915_EXEC_HANDLE_LUT<<1)
+/* If this flag is set userspace is using predicate and half slices can be
+ * let disabled for power saving. Otherwise use all slices even when disabled
+ * by boot parameter or via sysfs interface
+ */
+#define I915_EXEC_USE_PREDICATE (1<<13)
+
+#define __I915_EXEC_UNKNOWN_FLAGS -(I915_EXEC_USE_PREDICATE<<1)
#define I915_EXEC_CONTEXT_ID_MASK (0xffffffff)
#define i915_execbuffer2_set_context_id(eb2, context) \
--
1.7.11.7
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