[PATCH 1/2] drm/i915: add multi-threaded forcewake support
Keith Packard
keithp at keithp.com
Fri Nov 18 20:39:01 PST 2011
On IVB C0+ with newer BIOSes, the forcewake handshake has changed. There's
now a bitfield for different driver components to keep the GT powered
on. On Linux, we centralize forcewake handling in one place, so we
still just need a single bit, but we need to use the new registers if MT
forcewake is enabled.
This needs testing on affected machines. Please reply with your
tested-by if you had problems after a BIOS upgrade and this patch fixes
them.
v2: force MT mode. shift by 16
v3: set MT force wake bits then check ECOBUS
Tested-by: Keith Packard <keithp at keithp.com>
Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org>
Signed-off-by: Keith Packard <keithp at keithp.com>
---
drivers/gpu/drm/i915/i915_drv.c | 35 ++++++++++++++++++++++++++++--=
---
drivers/gpu/drm/i915/i915_drv.h | 13 ++++++++++-
drivers/gpu/drm/i915/i915_reg.h | 4 +++
drivers/gpu/drm/i915/intel_display.c | 22 +++++++++++++++++++++
4 files changed, 66 insertions(+), 8 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_dr=
v.c
index 13488be..bd82ef0 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -327,7 +327,7 @@ void intel_detect_pch(struct drm_device *dev)
}
}
=20
-static void __gen6_gt_force_wake_get(struct drm_i915_private *dev_priv)
+void __gen6_gt_force_wake_get(struct drm_i915_private *dev_priv)
{
int count;
=20
@@ -343,6 +343,22 @@ static void __gen6_gt_force_wake_get(struct drm_i915_p=
rivate *dev_priv)
udelay(10);
}
=20
+void __gen6_gt_force_wake_mt_get(struct drm_i915_private *dev_priv)
+{
+ int count;
+
+ count =3D 0;
+ while (count++ < 50 && (I915_READ_NOTRACE(FORCEWAKE_MT_ACK) & 1))
+ udelay(10);
+
+ I915_WRITE_NOTRACE(FORCEWAKE_MT, (1<<16) | 1);
+ POSTING_READ(FORCEWAKE_MT);
+
+ count =3D 0;
+ while (count++ < 50 && (I915_READ_NOTRACE(FORCEWAKE_MT_ACK) & 1) =3D=3D 0=
)
+ udelay(10);
+}
+
/*
* Generally this is called implicitly by the register read function. Howe=
ver,
* if some sequence requires the GT to not power down then this function s=
hould
@@ -355,15 +371,21 @@ void gen6_gt_force_wake_get(struct drm_i915_private *=
dev_priv)
=20
/* Forcewake is atomic in case we get in here without the lock */
if (atomic_add_return(1, &dev_priv->forcewake_count) =3D=3D 1)
- __gen6_gt_force_wake_get(dev_priv);
+ dev_priv->display.force_wake_get(dev_priv);
}
=20
-static void __gen6_gt_force_wake_put(struct drm_i915_private *dev_priv)
+void __gen6_gt_force_wake_put(struct drm_i915_private *dev_priv)
{
I915_WRITE_NOTRACE(FORCEWAKE, 0);
POSTING_READ(FORCEWAKE);
}
=20
+void __gen6_gt_force_wake_mt_put(struct drm_i915_private *dev_priv)
+{
+ I915_WRITE_NOTRACE(FORCEWAKE_MT, (1<<16) | 0);
+ POSTING_READ(FORCEWAKE_MT);
+}
+
/*
* see gen6_gt_force_wake_get()
*/
@@ -372,7 +394,7 @@ void gen6_gt_force_wake_put(struct drm_i915_private *de=
v_priv)
WARN_ON(!mutex_is_locked(&dev_priv->dev->struct_mutex));
=20
if (atomic_dec_and_test(&dev_priv->forcewake_count))
- __gen6_gt_force_wake_put(dev_priv);
+ dev_priv->display.force_wake_put(dev_priv);
}
=20
void __gen6_gt_wait_for_fifo(struct drm_i915_private *dev_priv)
@@ -902,8 +924,9 @@ MODULE_LICENSE("GPL and additional rights");
/* We give fast paths for the really cool registers */
#define NEEDS_FORCE_WAKE(dev_priv, reg) \
(((dev_priv)->info->gen >=3D 6) && \
- ((reg) < 0x40000) && \
- ((reg) !=3D FORCEWAKE))
+ ((reg) < 0x40000) && \
+ ((reg) !=3D FORCEWAKE) && \
+ ((reg) !=3D ECOBUS))
=20
#define __i915_read(x, y) \
u##x i915_read##x(struct drm_i915_private *dev_priv, u32 reg) { \
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_dr=
v.h
index 4a9c1b9..8ba88cf 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -107,6 +107,7 @@ struct opregion_header;
struct opregion_acpi;
struct opregion_swsci;
struct opregion_asle;
+struct drm_i915_private;
=20
struct intel_opregion {
struct opregion_header *header;
@@ -221,6 +222,8 @@ struct drm_i915_display_funcs {
struct drm_i915_gem_object *obj);
int (*update_plane)(struct drm_crtc *crtc, struct drm_framebuffer *fb,
int x, int y);
+ void (*force_wake_get)(struct drm_i915_private *dev_priv);
+ void (*force_wake_put)(struct drm_i915_private *dev_priv);
/* clock updates for mode set */
/* cursor updates */
/* render clock increase/decrease */
@@ -1308,6 +1311,11 @@ extern void gen6_set_rps(struct drm_device *dev, u8 =
val);
extern void intel_detect_pch(struct drm_device *dev);
extern int intel_trans_dp_port_sel(struct drm_crtc *crtc);
=20
+extern void __gen6_gt_force_wake_get(struct drm_i915_private *dev_priv);
+extern void __gen6_gt_force_wake_mt_get(struct drm_i915_private *dev_priv)=
;
+extern void __gen6_gt_force_wake_put(struct drm_i915_private *dev_priv);
+extern void __gen6_gt_force_wake_mt_put(struct drm_i915_private *dev_priv)=
;
+
/* overlay */
#ifdef CONFIG_DEBUG_FS
extern struct intel_overlay_error_state *intel_overlay_capture_error_state=
(struct drm_device *dev);
@@ -1352,8 +1360,9 @@ void __gen6_gt_wait_for_fifo(struct drm_i915_private =
*dev_priv);
/* We give fast paths for the really cool registers */
#define NEEDS_FORCE_WAKE(dev_priv, reg) \
(((dev_priv)->info->gen >=3D 6) && \
- ((reg) < 0x40000) && \
- ((reg) !=3D FORCEWAKE))
+ ((reg) < 0x40000) && \
+ ((reg) !=3D FORCEWAKE) && \
+ ((reg) !=3D ECOBUS))
=20
#define __i915_read(x, y) \
u##x i915_read##x(struct drm_i915_private *dev_priv, u32 reg);
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_re=
g.h
index b080cc8..8990057 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -3449,6 +3449,10 @@
=20
#define FORCEWAKE 0xA18C
#define FORCEWAKE_ACK 0x130090
+#define FORCEWAKE_MT 0xa188 /* multi-threaded */
+#define FORCEWAKE_MT_ACK 0x130040
+#define ECOBUS 0xa180
+#define FORCEWAKE_MT_ENABLE (1<<5)
=20
#define GT_FIFO_FREE_ENTRIES 0x120008
#define GT_FIFO_NUM_RESERVED_ENTRIES 20
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/in=
tel_display.c
index e77a863..633c693 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -8491,6 +8491,28 @@ static void intel_init_display(struct drm_device *de=
v)
=20
/* For FIFO watermark updates */
if (HAS_PCH_SPLIT(dev)) {
+ dev_priv->display.force_wake_get =3D __gen6_gt_force_wake_get;
+ dev_priv->display.force_wake_put =3D __gen6_gt_force_wake_put;
+
+ /* IVB configs may use multi-threaded forcewake */
+ if (IS_IVYBRIDGE(dev)) {
+ u32 ecobus;
+
+ mutex_lock(&dev->struct_mutex);
+ __gen6_gt_force_wake_mt_get(dev_priv);
+ ecobus =3D I915_READ(ECOBUS);
+ __gen6_gt_force_wake_mt_put(dev_priv);
+ mutex_unlock(&dev->struct_mutex);
+
+ if (ecobus & FORCEWAKE_MT_ENABLE) {
+ DRM_DEBUG_KMS("Using MT version of forcewake\n");
+ dev_priv->display.force_wake_get =3D
+ __gen6_gt_force_wake_mt_get;
+ dev_priv->display.force_wake_put =3D
+ __gen6_gt_force_wake_mt_put;
+ }
+ }
+
if (HAS_PCH_IBX(dev))
dev_priv->display.init_pch_clock_gating =3D ibx_init_clock_gating;
else if (HAS_PCH_CPT(dev))
--=20
1.7.7.3
--=20
keith.packard at intel.com
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