[Intel-gfx] [PATCH 2/3] drm/i915: deprecate _SHIFT in favor of FIELD_GET() and _MASK

Jani Nikula jani.nikula at intel.com
Wed Oct 3 16:05:22 UTC 2018


bitfield.h defines FIELD_GET() and FIELD_PREP() macros to access
bitfields using the mask alone, with no need for separate shift. Indeed,
the shift is redundant.

For the most part, FIELD_GET() is shorter than masking followed by
shift, and arguably has more clarity.

FIELD_PREP() can get more verbose than simply shifting in place, but it
does provide masking to ensure we don't overflow the mask, something we
usually don't bother with currently.

Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula at intel.com>
---
 drivers/gpu/drm/i915/i915_reg.h   | 21 ++++++--------------
 drivers/gpu/drm/i915/intel_dp.c   | 40 ++++++++++++++++-----------------------
 drivers/gpu/drm/i915/intel_lvds.c | 40 ++++++++++++++++++---------------------
 3 files changed, 40 insertions(+), 61 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index ac9258769435..dce4a6ac394c 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -25,6 +25,7 @@
 #ifndef _I915_REG_H_
 #define _I915_REG_H_
 
+#include <linux/bitfield.h>
 #include <linux/bits.h>
 
 /**
@@ -61,11 +62,11 @@
  * significant to least significant bit. Indent the register content macros
  * using two extra spaces between ``#define`` and the macro name.
  *
- * For bit fields, define a ``_MASK`` and a ``_SHIFT`` macro. Use
- * ``REG_FIELD_MASK()`` to define _MASK. Define bit field contents so that they
- * are already shifted in place, and can be directly OR'd. For convenience,
- * function-like macros may be used to define bit fields, but do note that the
- * macros may be needed to read as well as write the register contents.
+ * Define bit fields using ``REG_FIELD_MASK(h, l)``. Define bit field contents
+ * so that they are already shifted in place, and can be directly OR'd. For
+ * convenience, function-like macros may be used to define bit fields, but do
+ * note that the macros may be needed to read as well as write the register
+ * contents.
  *
  * Define bits using ``REG_BIT(N)``. Do **not** add ``_BIT`` suffix to the name.
  *
@@ -107,7 +108,6 @@
  *  #define FOO(pipe)                   _MMIO_PIPE(pipe, _FOO_A, _FOO_B)
  *  #define   FOO_ENABLE                REG_BIT(31)
  *  #define   FOO_MODE_MASK             REG_FIELD_MASK(19, 16)
- *  #define   FOO_MODE_SHIFT            16
  *  #define   FOO_MODE_BAR              (0 << 16)
  *  #define   FOO_MODE_BAZ              (1 << 16)
  *  #define   FOO_MODE_QUX_SNB          (2 << 16)
@@ -4636,7 +4636,6 @@ enum {
 #define   PP_SEQUENCE_NONE		(0 << 28)
 #define   PP_SEQUENCE_POWER_UP		(1 << 28)
 #define   PP_SEQUENCE_POWER_DOWN	(2 << 28)
-#define   PP_SEQUENCE_SHIFT		28
 #define   PP_CYCLE_DELAY_ACTIVE		REG_BIT(27)
 #define   PP_SEQUENCE_STATE_MASK	REG_FIELD_MASK(3, 0)
 #define   PP_SEQUENCE_STATE_OFF_IDLE	(0x0 << 0)
@@ -4654,7 +4653,6 @@ enum {
 #define  PANEL_UNLOCK_MASK		REG_FIELD_MASK(31, 16)
 #define  PANEL_UNLOCK_REGS		(0xabcd << 16)
 #define  BXT_POWER_CYCLE_DELAY_MASK	REG_FIELD_MASK(8, 4)
-#define  BXT_POWER_CYCLE_DELAY_SHIFT	4
 #define  EDP_FORCE_VDD			REG_BIT(3)
 #define  EDP_BLC_ENABLE			REG_BIT(2)
 #define  PANEL_POWER_RESET		REG_BIT(1)
@@ -4662,7 +4660,6 @@ enum {
 
 #define _PP_ON_DELAYS			0x61208
 #define PP_ON_DELAYS(pps_idx)		_MMIO_PPS(pps_idx, _PP_ON_DELAYS)
-#define  PANEL_PORT_SELECT_SHIFT	30
 #define  PANEL_PORT_SELECT_MASK		REG_FIELD_MASK(31, 30)
 #define  PANEL_PORT_SELECT_LVDS		(0 << 30)
 #define  PANEL_PORT_SELECT_DPA		(1 << 30)
@@ -4670,23 +4667,17 @@ enum {
 #define  PANEL_PORT_SELECT_DPD		(3 << 30)
 #define  PANEL_PORT_SELECT_VLV(port)	((port) << 30)
 #define  PANEL_POWER_UP_DELAY_MASK	REG_FIELD_MASK(28, 16)
-#define  PANEL_POWER_UP_DELAY_SHIFT	16
 #define  PANEL_LIGHT_ON_DELAY_MASK	REG_FIELD_MASK(12, 0)
-#define  PANEL_LIGHT_ON_DELAY_SHIFT	0
 
 #define _PP_OFF_DELAYS			0x6120C
 #define PP_OFF_DELAYS(pps_idx)		_MMIO_PPS(pps_idx, _PP_OFF_DELAYS)
 #define  PANEL_POWER_DOWN_DELAY_MASK	REG_FIELD_MASK(28, 16)
-#define  PANEL_POWER_DOWN_DELAY_SHIFT	16
 #define  PANEL_LIGHT_OFF_DELAY_MASK	REG_FIELD_MASK(12, 0)
-#define  PANEL_LIGHT_OFF_DELAY_SHIFT	0
 
 #define _PP_DIVISOR			0x61210
 #define PP_DIVISOR(pps_idx)		_MMIO_PPS(pps_idx, _PP_DIVISOR)
 #define  PP_REFERENCE_DIVIDER_MASK	REG_FIELD_MASK(31, 8)
-#define  PP_REFERENCE_DIVIDER_SHIFT	8
 #define  PANEL_POWER_CYCLE_DELAY_MASK	REG_FIELD_MASK(4, 0)
-#define  PANEL_POWER_CYCLE_DELAY_SHIFT	0
 
 /* Panel fitting */
 #define PFIT_CONTROL	_MMIO(dev_priv->info.display_mmio_offset + 0x61230)
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 31eef9b0e33b..848ce42d7770 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -5767,25 +5767,16 @@ intel_pps_readout_hw_state(struct intel_dp *intel_dp, struct edp_power_seq *seq)
 	}
 
 	/* Pull timing values out of registers */
-	seq->t1_t3 = (pp_on & PANEL_POWER_UP_DELAY_MASK) >>
-		     PANEL_POWER_UP_DELAY_SHIFT;
-
-	seq->t8 = (pp_on & PANEL_LIGHT_ON_DELAY_MASK) >>
-		  PANEL_LIGHT_ON_DELAY_SHIFT;
-
-	seq->t9 = (pp_off & PANEL_LIGHT_OFF_DELAY_MASK) >>
-		  PANEL_LIGHT_OFF_DELAY_SHIFT;
-
-	seq->t10 = (pp_off & PANEL_POWER_DOWN_DELAY_MASK) >>
-		   PANEL_POWER_DOWN_DELAY_SHIFT;
+	seq->t1_t3 = FIELD_GET(PANEL_POWER_UP_DELAY_MASK, pp_on);
+	seq->t8 = FIELD_GET(PANEL_LIGHT_ON_DELAY_MASK, pp_on);
+	seq->t9 = FIELD_GET(PANEL_LIGHT_OFF_DELAY_MASK, pp_off);
+	seq->t10 = FIELD_GET(PANEL_POWER_DOWN_DELAY_MASK, pp_off);
 
 	if (IS_GEN9_LP(dev_priv) || HAS_PCH_CNP(dev_priv) ||
 	    HAS_PCH_ICP(dev_priv)) {
-		seq->t11_t12 = ((pp_ctl & BXT_POWER_CYCLE_DELAY_MASK) >>
-				BXT_POWER_CYCLE_DELAY_SHIFT) * 1000;
+		seq->t11_t12 = FIELD_GET(BXT_POWER_CYCLE_DELAY_MASK, pp_ctl) * 1000;
 	} else {
-		seq->t11_t12 = ((pp_div & PANEL_POWER_CYCLE_DELAY_MASK) >>
-		       PANEL_POWER_CYCLE_DELAY_SHIFT) * 1000;
+		seq->t11_t12 = FIELD_GET(PANEL_POWER_CYCLE_DELAY_MASK, pp_div) * 1000;
 	}
 }
 
@@ -5945,22 +5936,23 @@ intel_dp_init_panel_power_sequencer_registers(struct intel_dp *intel_dp,
 		I915_WRITE(regs.pp_ctrl, pp);
 	}
 
-	pp_on = (seq->t1_t3 << PANEL_POWER_UP_DELAY_SHIFT) |
-		(seq->t8 << PANEL_LIGHT_ON_DELAY_SHIFT);
-	pp_off = (seq->t9 << PANEL_LIGHT_OFF_DELAY_SHIFT) |
-		 (seq->t10 << PANEL_POWER_DOWN_DELAY_SHIFT);
+	pp_on = FIELD_PREP(PANEL_POWER_UP_DELAY_MASK, seq->t1_t3) |
+		FIELD_PREP(PANEL_LIGHT_ON_DELAY_MASK, seq->t8);
+	pp_off = FIELD_PREP(PANEL_LIGHT_OFF_DELAY_MASK, seq->t9) |
+		FIELD_PREP(PANEL_POWER_DOWN_DELAY_MASK, seq->t10);
 	/* Compute the divisor for the pp clock, simply match the Bspec
 	 * formula. */
 	if (IS_GEN9_LP(dev_priv) || HAS_PCH_CNP(dev_priv) ||
 	    HAS_PCH_ICP(dev_priv)) {
 		pp_div = I915_READ(regs.pp_ctrl);
 		pp_div &= ~BXT_POWER_CYCLE_DELAY_MASK;
-		pp_div |= (DIV_ROUND_UP(seq->t11_t12, 1000)
-				<< BXT_POWER_CYCLE_DELAY_SHIFT);
+		pp_div |= FIELD_PREP(BXT_POWER_CYCLE_DELAY_MASK,
+				     DIV_ROUND_UP(seq->t11_t12, 1000));
 	} else {
-		pp_div = ((100 * div)/2 - 1) << PP_REFERENCE_DIVIDER_SHIFT;
-		pp_div |= (DIV_ROUND_UP(seq->t11_t12, 1000)
-				<< PANEL_POWER_CYCLE_DELAY_SHIFT);
+		pp_div = FIELD_PREP(PP_REFERENCE_DIVIDER_MASK,
+				    (100 * div) / 2 - 1);
+		pp_div |= FIELD_PREP(PANEL_POWER_CYCLE_DELAY_MASK,
+				     DIV_ROUND_UP(seq->t11_t12, 1000));
 	}
 
 	/* Haswell doesn't have any port selection bits for the panel
diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c
index f9f3b0885ba5..285aee9e58f1 100644
--- a/drivers/gpu/drm/i915/intel_lvds.c
+++ b/drivers/gpu/drm/i915/intel_lvds.c
@@ -160,24 +160,17 @@ static void intel_lvds_pps_get_hw_state(struct drm_i915_private *dev_priv,
 	pps->powerdown_on_reset = I915_READ(PP_CONTROL(0)) & PANEL_POWER_RESET;
 
 	val = I915_READ(PP_ON_DELAYS(0));
-	pps->port = (val & PANEL_PORT_SELECT_MASK) >>
-		    PANEL_PORT_SELECT_SHIFT;
-	pps->t1_t2 = (val & PANEL_POWER_UP_DELAY_MASK) >>
-		     PANEL_POWER_UP_DELAY_SHIFT;
-	pps->t5 = (val & PANEL_LIGHT_ON_DELAY_MASK) >>
-		  PANEL_LIGHT_ON_DELAY_SHIFT;
+	pps->port = FIELD_GET(PANEL_PORT_SELECT_MASK, val);
+	pps->t1_t2 = FIELD_GET(PANEL_POWER_UP_DELAY_MASK, val);
+	pps->t5 = FIELD_GET(PANEL_LIGHT_ON_DELAY_MASK, val);
 
 	val = I915_READ(PP_OFF_DELAYS(0));
-	pps->t3 = (val & PANEL_POWER_DOWN_DELAY_MASK) >>
-		  PANEL_POWER_DOWN_DELAY_SHIFT;
-	pps->tx = (val & PANEL_LIGHT_OFF_DELAY_MASK) >>
-		  PANEL_LIGHT_OFF_DELAY_SHIFT;
+	pps->t3 = FIELD_GET(PANEL_POWER_DOWN_DELAY_MASK, val);
+	pps->tx = FIELD_GET(PANEL_LIGHT_OFF_DELAY_MASK, val);
 
 	val = I915_READ(PP_DIVISOR(0));
-	pps->divider = (val & PP_REFERENCE_DIVIDER_MASK) >>
-		       PP_REFERENCE_DIVIDER_SHIFT;
-	val = (val & PANEL_POWER_CYCLE_DELAY_MASK) >>
-	      PANEL_POWER_CYCLE_DELAY_SHIFT;
+	pps->divider = FIELD_GET(PP_REFERENCE_DIVIDER_MASK, val);
+	val = FIELD_GET(PANEL_POWER_CYCLE_DELAY_MASK, val);
 	/*
 	 * Remove the BSpec specified +1 (100ms) offset that accounts for a
 	 * too short power-cycle delay due to the asynchronous programming of
@@ -217,15 +210,18 @@ static void intel_lvds_pps_init_hw(struct drm_i915_private *dev_priv,
 		val |= PANEL_POWER_RESET;
 	I915_WRITE(PP_CONTROL(0), val);
 
-	I915_WRITE(PP_ON_DELAYS(0), (pps->port << PANEL_PORT_SELECT_SHIFT) |
-				    (pps->t1_t2 << PANEL_POWER_UP_DELAY_SHIFT) |
-				    (pps->t5 << PANEL_LIGHT_ON_DELAY_SHIFT));
-	I915_WRITE(PP_OFF_DELAYS(0), (pps->t3 << PANEL_POWER_DOWN_DELAY_SHIFT) |
-				     (pps->tx << PANEL_LIGHT_OFF_DELAY_SHIFT));
+	val = FIELD_PREP(PANEL_PORT_SELECT_MASK, pps->port) |
+		FIELD_PREP(PANEL_POWER_UP_DELAY_MASK, pps->t1_t2) |
+		FIELD_PREP(PANEL_LIGHT_ON_DELAY_MASK, pps->t5);
+	I915_WRITE(PP_ON_DELAYS(0), val);
 
-	val = pps->divider << PP_REFERENCE_DIVIDER_SHIFT;
-	val |= (DIV_ROUND_UP(pps->t4, 1000) + 1) <<
-	       PANEL_POWER_CYCLE_DELAY_SHIFT;
+	val = FIELD_PREP(PANEL_POWER_DOWN_DELAY_MASK, pps->t3) |
+		FIELD_PREP(PANEL_LIGHT_OFF_DELAY_MASK, pps->tx);
+	I915_WRITE(PP_OFF_DELAYS(0), val);
+
+	val = FIELD_PREP(PP_REFERENCE_DIVIDER_MASK, pps->divider) |
+		FIELD_PREP(PANEL_POWER_CYCLE_DELAY_MASK,
+			   DIV_ROUND_UP(pps->t4, 1000) + 1);
 	I915_WRITE(PP_DIVISOR(0), val);
 }
 
-- 
2.11.0



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