diff mbox

[v3] drm/i915/bdw: Fix the write setting up the WIZ hashing mode

Message ID 1418060031-4766-1-git-send-email-damien.lespiau@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Lespiau, Damien Dec. 8, 2014, 5:33 p.m. UTC
I was playing with clang and oh surprise! a warning trigerred by
-Wshift-overflow (gcc doesn't have this one):

    WA_SET_BIT_MASKED(GEN7_GT_MODE,
                      GEN6_WIZ_HASHING_MASK | GEN6_WIZ_HASHING_16x4);

    drivers/gpu/drm/i915/intel_ringbuffer.c:786:2: warning: signed shift result
      (0x28002000000) requires 43 bits to represent, but 'int' only has 32 bits
      [-Wshift-overflow]
        WA_SET_BIT_MASKED(GEN7_GT_MODE,
        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    drivers/gpu/drm/i915/intel_ringbuffer.c:737:15: note: expanded from macro
      'WA_SET_BIT_MASKED'
        WA_REG(addr, _MASKED_BIT_ENABLE(mask), (mask) & 0xffff)

Turned out GEN6_WIZ_HASHING_MASK was already shifted by 16, and we were
trying to shift it a bit more.

The other thing is that it's not the usual case of setting WA bits here, we
need to have separate mask and value.

To fix this, I've introduced a new _MASKED_FIELD() macro that takes both the
(unshifted) mask and the desired value and the rest of the patch ripples
through from it.

This bug was introduced when reworking the WA emission in:

  Commit 7225342ab501befdb64bcec76ded41f5897c0855
  Author: Mika Kuoppala <mika.kuoppala@linux.intel.com>
  Date:   Tue Oct 7 17:21:26 2014 +0300

      drm/i915: Build workaround list in ring initialization

v2: Invert the order of the mask and value arguments (Daniel Vetter)
    Rewrite _MASKED_BIT_ENABLE() and _MASKED_BIT_DISABLE() with
    _MASKED_FIELD() (Jani Nikula)
    Make sure we only evaluate 'a' once in _MASKED_BIT_ENABLE() (Dave Gordon)
    Add check to ensure the value is within the mask boundaries (Chris Wilson)

v3: Ensure the the value and mask are 16 bits (Dave Gordon)

Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Arun Siluvery <arun.siluvery@linux.intel.com>
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
---
 drivers/gpu/drm/i915/i915_reg.h         | 17 ++++++++++++++---
 drivers/gpu/drm/i915/intel_pm.c         |  6 +++---
 drivers/gpu/drm/i915/intel_ringbuffer.c |  8 ++++++--
 3 files changed, 23 insertions(+), 8 deletions(-)

Comments

Shuang He Dec. 9, 2014, 10:14 p.m. UTC | #1
Tested-By: PRC QA PRTS (Patch Regression Test System Contact: shuang.he@intel.com)
-------------------------------------Summary-------------------------------------
Platform          Delta          drm-intel-nightly          Series Applied
PNV                                  364/364              364/364
ILK              +1                 364/366              365/366
SNB                                  448/450              448/450
IVB                                  497/498              497/498
BYT                                  289/289              289/289
HSW                                  563/564              563/564
BDW                                  417/417              417/417
-------------------------------------Detailed-------------------------------------
Platform  Test                                drm-intel-nightly          Series Applied
 ILK  igt_kms_flip_wf_vblank-ts-check      DMESG_WARN(1, M26)PASS(9, M26M37)      PASS(1, M37)
Note: You need to pay more attention to line start with '*'
Jani Nikula Dec. 10, 2014, 9:42 a.m. UTC | #2
On Mon, 08 Dec 2014, Damien Lespiau <damien.lespiau@intel.com> wrote:
> I was playing with clang and oh surprise! a warning trigerred by
> -Wshift-overflow (gcc doesn't have this one):
>
>     WA_SET_BIT_MASKED(GEN7_GT_MODE,
>                       GEN6_WIZ_HASHING_MASK | GEN6_WIZ_HASHING_16x4);
>
>     drivers/gpu/drm/i915/intel_ringbuffer.c:786:2: warning: signed shift result
>       (0x28002000000) requires 43 bits to represent, but 'int' only has 32 bits
>       [-Wshift-overflow]
>         WA_SET_BIT_MASKED(GEN7_GT_MODE,
>         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>     drivers/gpu/drm/i915/intel_ringbuffer.c:737:15: note: expanded from macro
>       'WA_SET_BIT_MASKED'
>         WA_REG(addr, _MASKED_BIT_ENABLE(mask), (mask) & 0xffff)
>
> Turned out GEN6_WIZ_HASHING_MASK was already shifted by 16, and we were
> trying to shift it a bit more.
>
> The other thing is that it's not the usual case of setting WA bits here, we
> need to have separate mask and value.
>
> To fix this, I've introduced a new _MASKED_FIELD() macro that takes both the
> (unshifted) mask and the desired value and the rest of the patch ripples
> through from it.
>
> This bug was introduced when reworking the WA emission in:
>
>   Commit 7225342ab501befdb64bcec76ded41f5897c0855
>   Author: Mika Kuoppala <mika.kuoppala@linux.intel.com>
>   Date:   Tue Oct 7 17:21:26 2014 +0300
>
>       drm/i915: Build workaround list in ring initialization
>
> v2: Invert the order of the mask and value arguments (Daniel Vetter)
>     Rewrite _MASKED_BIT_ENABLE() and _MASKED_BIT_DISABLE() with
>     _MASKED_FIELD() (Jani Nikula)
>     Make sure we only evaluate 'a' once in _MASKED_BIT_ENABLE() (Dave Gordon)
>     Add check to ensure the value is within the mask boundaries (Chris Wilson)
>
> v3: Ensure the the value and mask are 16 bits (Dave Gordon)
>
> Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
> Cc: Arun Siluvery <arun.siluvery@linux.intel.com>
> Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>

Pushed to drm-intel-next-fixes, replacing the old version. Thanks for
the patch.

Now the question is, do we want [1] for 3.19 or 3.20?

BR,
Jani.


http://mid.gmane.org/1418060138-5004-1-git-send-email-damien.lespiau@intel.com


> ---
>  drivers/gpu/drm/i915/i915_reg.h         | 17 ++++++++++++++---
>  drivers/gpu/drm/i915/intel_pm.c         |  6 +++---
>  drivers/gpu/drm/i915/intel_ringbuffer.c |  8 ++++++--
>  3 files changed, 23 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index dc03fac..454a3a3 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -34,8 +34,19 @@
>  #define _PORT3(port, a, b, c) ((port) == PORT_A ? (a) : \
>  			       (port) == PORT_B ? (b) : (c))
>  
> -#define _MASKED_BIT_ENABLE(a) (((a) << 16) | (a))
> -#define _MASKED_BIT_DISABLE(a) ((a) << 16)
> +#define _MASKED_FIELD(mask, value) ({					   \
> +	if (__builtin_constant_p(mask))					   \
> +		BUILD_BUG_ON_MSG(((mask) & 0xffff0000), "Incorrect mask"); \
> +	if (__builtin_constant_p(value))				   \
> +		BUILD_BUG_ON_MSG((value) & 0xffff0000, "Incorrect value"); \
> +	if (__builtin_constant_p(mask) && __builtin_constant_p(value))	   \
> +		BUILD_BUG_ON_MSG((value) & ~(mask),			   \
> +				 "Incorrect value for mask");		   \
> +	(mask) << 16 | (value); })
> +#define _MASKED_BIT_ENABLE(a)	({ typeof(a) _a = (a); _MASKED_FIELD(_a, _a); })
> +#define _MASKED_BIT_DISABLE(a)	(_MASKED_FIELD((a), 0))
> +
> +
>  
>  /* PCI config space */
>  
> @@ -1284,7 +1295,7 @@ enum punit_power_well {
>  #define   GEN6_WIZ_HASHING_8x8				GEN6_WIZ_HASHING(0, 0)
>  #define   GEN6_WIZ_HASHING_8x4				GEN6_WIZ_HASHING(0, 1)
>  #define   GEN6_WIZ_HASHING_16x4				GEN6_WIZ_HASHING(1, 0)
> -#define   GEN6_WIZ_HASHING_MASK				(GEN6_WIZ_HASHING(1, 1) << 16)
> +#define   GEN6_WIZ_HASHING_MASK				GEN6_WIZ_HASHING(1, 1)
>  #define   GEN6_TD_FOUR_ROW_DISPATCH_DISABLE		(1 << 5)
>  
>  #define GFX_MODE	0x02520
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index 78911e2..0f2febd 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -6389,7 +6389,7 @@ static void gen6_init_clock_gating(struct drm_device *dev)
>  	 * to keep in mind (see 3DSTATE_PS and 3DSTATE_WM).
>  	 */
>  	I915_WRITE(GEN6_GT_MODE,
> -		   GEN6_WIZ_HASHING_MASK | GEN6_WIZ_HASHING_16x4);
> +		   _MASKED_FIELD(GEN6_WIZ_HASHING_MASK, GEN6_WIZ_HASHING_16x4));
>  
>  	ilk_init_lp_watermarks(dev);
>  
> @@ -6587,7 +6587,7 @@ static void haswell_init_clock_gating(struct drm_device *dev)
>  	 * to keep in mind (see 3DSTATE_PS and 3DSTATE_WM).
>  	 */
>  	I915_WRITE(GEN7_GT_MODE,
> -		   GEN6_WIZ_HASHING_MASK | GEN6_WIZ_HASHING_16x4);
> +		   _MASKED_FIELD(GEN6_WIZ_HASHING_MASK, GEN6_WIZ_HASHING_16x4));
>  
>  	/* WaSwitchSolVfFArbitrationPriority:hsw */
>  	I915_WRITE(GAM_ECOCHK, I915_READ(GAM_ECOCHK) | HSW_ECOCHK_ARB_PRIO_SOL);
> @@ -6684,7 +6684,7 @@ static void ivybridge_init_clock_gating(struct drm_device *dev)
>  	 * to keep in mind (see 3DSTATE_PS and 3DSTATE_WM).
>  	 */
>  	I915_WRITE(GEN7_GT_MODE,
> -		   GEN6_WIZ_HASHING_MASK | GEN6_WIZ_HASHING_16x4);
> +		   _MASKED_FIELD(GEN6_WIZ_HASHING_MASK, GEN6_WIZ_HASHING_16x4));
>  
>  	snpcr = I915_READ(GEN6_MBCUNIT_SNPCR);
>  	snpcr &= ~GEN6_MBC_SNPCR_MASK;
> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
> index 79b4ca5..9deb152 100644
> --- a/drivers/gpu/drm/i915/intel_ringbuffer.c
> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
> @@ -739,6 +739,9 @@ static int wa_add(struct drm_i915_private *dev_priv,
>  #define WA_CLR_BIT_MASKED(addr, mask) \
>  	WA_REG(addr, _MASKED_BIT_DISABLE(mask), (mask) & 0xffff)
>  
> +#define WA_SET_FIELD_MASKED(addr, mask, value) \
> +	WA_REG(addr, _MASKED_FIELD(mask, value), mask)
> +
>  #define WA_SET_BIT(addr, mask) WA_REG(addr, I915_READ(addr) | (mask), mask)
>  #define WA_CLR_BIT(addr, mask) WA_REG(addr, I915_READ(addr) & ~(mask), mask)
>  
> @@ -783,8 +786,9 @@ static int bdw_init_workarounds(struct intel_engine_cs *ring)
>  	 * disable bit, which we don't touch here, but it's good
>  	 * to keep in mind (see 3DSTATE_PS and 3DSTATE_WM).
>  	 */
> -	WA_SET_BIT_MASKED(GEN7_GT_MODE,
> -			  GEN6_WIZ_HASHING_MASK | GEN6_WIZ_HASHING_16x4);
> +	WA_SET_FIELD_MASKED(GEN7_GT_MODE,
> +			    GEN6_WIZ_HASHING_MASK,
> +			    GEN6_WIZ_HASHING_16x4);
>  
>  	return 0;
>  }
> -- 
> 1.8.3.1
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
Lespiau, Damien Dec. 10, 2014, 12:03 p.m. UTC | #3
On Wed, Dec 10, 2014 at 11:42:13AM +0200, Jani Nikula wrote:
> Pushed to drm-intel-next-fixes, replacing the old version. Thanks for
> the patch.
> 
> Now the question is, do we want [1] for 3.19 or 3.20?
> 
> [1] http://mid.gmane.org/1418060138-5004-1-git-send-email-damien.lespiau@intel.com

I think that one is for 3.20, not really fixing a bug.
Daniel Vetter Dec. 10, 2014, 1:55 p.m. UTC | #4
On Wed, Dec 10, 2014 at 12:03:20PM +0000, Damien Lespiau wrote:
> On Wed, Dec 10, 2014 at 11:42:13AM +0200, Jani Nikula wrote:
> > Pushed to drm-intel-next-fixes, replacing the old version. Thanks for
> > the patch.
> > 
> > Now the question is, do we want [1] for 3.19 or 3.20?
> > 
> > [1] http://mid.gmane.org/1418060138-5004-1-git-send-email-damien.lespiau@intel.com
> 
> I think that one is for 3.20, not really fixing a bug.

I suggested 3.19/dinf because it'll make merging easier. And it's
expressingly ok for Linus to merge cleanup stuff even in the merge
window/-rc1 if it makes things easier (as long as it's just obvious
refactoring without any functional change).
-Daniel
diff mbox

Patch

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index dc03fac..454a3a3 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -34,8 +34,19 @@ 
 #define _PORT3(port, a, b, c) ((port) == PORT_A ? (a) : \
 			       (port) == PORT_B ? (b) : (c))
 
-#define _MASKED_BIT_ENABLE(a) (((a) << 16) | (a))
-#define _MASKED_BIT_DISABLE(a) ((a) << 16)
+#define _MASKED_FIELD(mask, value) ({					   \
+	if (__builtin_constant_p(mask))					   \
+		BUILD_BUG_ON_MSG(((mask) & 0xffff0000), "Incorrect mask"); \
+	if (__builtin_constant_p(value))				   \
+		BUILD_BUG_ON_MSG((value) & 0xffff0000, "Incorrect value"); \
+	if (__builtin_constant_p(mask) && __builtin_constant_p(value))	   \
+		BUILD_BUG_ON_MSG((value) & ~(mask),			   \
+				 "Incorrect value for mask");		   \
+	(mask) << 16 | (value); })
+#define _MASKED_BIT_ENABLE(a)	({ typeof(a) _a = (a); _MASKED_FIELD(_a, _a); })
+#define _MASKED_BIT_DISABLE(a)	(_MASKED_FIELD((a), 0))
+
+
 
 /* PCI config space */
 
@@ -1284,7 +1295,7 @@  enum punit_power_well {
 #define   GEN6_WIZ_HASHING_8x8				GEN6_WIZ_HASHING(0, 0)
 #define   GEN6_WIZ_HASHING_8x4				GEN6_WIZ_HASHING(0, 1)
 #define   GEN6_WIZ_HASHING_16x4				GEN6_WIZ_HASHING(1, 0)
-#define   GEN6_WIZ_HASHING_MASK				(GEN6_WIZ_HASHING(1, 1) << 16)
+#define   GEN6_WIZ_HASHING_MASK				GEN6_WIZ_HASHING(1, 1)
 #define   GEN6_TD_FOUR_ROW_DISPATCH_DISABLE		(1 << 5)
 
 #define GFX_MODE	0x02520
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 78911e2..0f2febd 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -6389,7 +6389,7 @@  static void gen6_init_clock_gating(struct drm_device *dev)
 	 * to keep in mind (see 3DSTATE_PS and 3DSTATE_WM).
 	 */
 	I915_WRITE(GEN6_GT_MODE,
-		   GEN6_WIZ_HASHING_MASK | GEN6_WIZ_HASHING_16x4);
+		   _MASKED_FIELD(GEN6_WIZ_HASHING_MASK, GEN6_WIZ_HASHING_16x4));
 
 	ilk_init_lp_watermarks(dev);
 
@@ -6587,7 +6587,7 @@  static void haswell_init_clock_gating(struct drm_device *dev)
 	 * to keep in mind (see 3DSTATE_PS and 3DSTATE_WM).
 	 */
 	I915_WRITE(GEN7_GT_MODE,
-		   GEN6_WIZ_HASHING_MASK | GEN6_WIZ_HASHING_16x4);
+		   _MASKED_FIELD(GEN6_WIZ_HASHING_MASK, GEN6_WIZ_HASHING_16x4));
 
 	/* WaSwitchSolVfFArbitrationPriority:hsw */
 	I915_WRITE(GAM_ECOCHK, I915_READ(GAM_ECOCHK) | HSW_ECOCHK_ARB_PRIO_SOL);
@@ -6684,7 +6684,7 @@  static void ivybridge_init_clock_gating(struct drm_device *dev)
 	 * to keep in mind (see 3DSTATE_PS and 3DSTATE_WM).
 	 */
 	I915_WRITE(GEN7_GT_MODE,
-		   GEN6_WIZ_HASHING_MASK | GEN6_WIZ_HASHING_16x4);
+		   _MASKED_FIELD(GEN6_WIZ_HASHING_MASK, GEN6_WIZ_HASHING_16x4));
 
 	snpcr = I915_READ(GEN6_MBCUNIT_SNPCR);
 	snpcr &= ~GEN6_MBC_SNPCR_MASK;
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 79b4ca5..9deb152 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -739,6 +739,9 @@  static int wa_add(struct drm_i915_private *dev_priv,
 #define WA_CLR_BIT_MASKED(addr, mask) \
 	WA_REG(addr, _MASKED_BIT_DISABLE(mask), (mask) & 0xffff)
 
+#define WA_SET_FIELD_MASKED(addr, mask, value) \
+	WA_REG(addr, _MASKED_FIELD(mask, value), mask)
+
 #define WA_SET_BIT(addr, mask) WA_REG(addr, I915_READ(addr) | (mask), mask)
 #define WA_CLR_BIT(addr, mask) WA_REG(addr, I915_READ(addr) & ~(mask), mask)
 
@@ -783,8 +786,9 @@  static int bdw_init_workarounds(struct intel_engine_cs *ring)
 	 * disable bit, which we don't touch here, but it's good
 	 * to keep in mind (see 3DSTATE_PS and 3DSTATE_WM).
 	 */
-	WA_SET_BIT_MASKED(GEN7_GT_MODE,
-			  GEN6_WIZ_HASHING_MASK | GEN6_WIZ_HASHING_16x4);
+	WA_SET_FIELD_MASKED(GEN7_GT_MODE,
+			    GEN6_WIZ_HASHING_MASK,
+			    GEN6_WIZ_HASHING_16x4);
 
 	return 0;
 }