Slightly verbose, but does away with hand rolled shifts. Ties the field
values with the mask defining the field.
Unfortunately we have to make a local copy of FIELD_PREP() to evaluate
to a integer constant expression. But with this, we can ensure the mask
is non-zero, power of 2, fits u32, and the value fits the mask (when the
value is a constant expression).
Convert power sequencer registers as an example.
v4:
- rebase
v3:
- rename the macro to REG_FIELD_PREP to avoid underscore prefix and to
be in line with kernel macros (Chris)
- rename power of 2 check macro (Chris)
v2:
- add build-time checks with BUILD_BUG_ON_ZERO()
- rename to just _FIELD() due to regmap.h REG_FIELD() clash
Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx>
Cc: Michal Wajdeczko <michal.wajdeczko@xxxxxxxxx>
Cc: Mika Kuoppala <mika.kuoppala@xxxxxxxxxxxxxxx>
Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
Reviewed-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
---
drivers/gpu/drm/i915/i915_reg.h | 69 +++++++++++++++++++--------------
1 file changed, 39 insertions(+), 30 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 31a3020e369d..477dfda38fc7 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -62,11 +62,11 @@
* significant to least significant bit. Indent the register content macros
* using two extra spaces between ``#define`` and the macro name.
*
- * Define bit fields using ``REG_GENMASK(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 bit fields using ``REG_GENMASK(h, l)``. Define bit field contents
+ * using ``REG_FIELD_PREP(mask, value)``. This will define the values already
+ * shifted in place, so they can be directly OR'd together. 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.
*
@@ -108,9 +108,9 @@
* #define FOO(pipe) _MMIO_PIPE(pipe, _FOO_A, _FOO_B)
* #define FOO_ENABLE REG_BIT(31)
* #define FOO_MODE_MASK REG_GENMASK(19, 16)
- * #define FOO_MODE_BAR (0 << 16)
- * #define FOO_MODE_BAZ (1 << 16)
- * #define FOO_MODE_QUX_SNB (2 << 16)
+ * #define FOO_MODE_BAR REG_FIELD_PREP(FOO_MODE_MASK, 0)
+ * #define FOO_MODE_BAZ REG_FIELD_PREP(FOO_MODE_MASK, 1)
+ * #define FOO_MODE_QUX_SNB REG_FIELD_PREP(FOO_MODE_MASK, 2)
*
* #define BAR _MMIO(0xb000)
* #define GEN8_BAR _MMIO(0xb888)
@@ -144,17 +144,27 @@
__builtin_constant_p(__low) && \
((__low) < 0 || (__high) > 31 || (__low) > (__high)))))
+/*
+ * Local integer constant expression version of is_power_of_2().
+ */
+#define IS_POWER_OF_2(__x) ((__x) && (((__x) & ((__x) - 1)) == 0))
+
/**
* REG_FIELD_PREP() - Prepare a u32 bitfield value
* @__mask: shifted mask defining the field's length and position
* @__val: value to put in the field
- * Local wrapper for FIELD_PREP() to force u32 and for consistency with
- * REG_FIELD_GET(), REG_BIT() and REG_GENMASK().
+ * Local copy of FIELD_PREP() to generate an integer constant expression, force
+ * u32 and for consistency with REG_FIELD_GET(), REG_BIT() and REG_GENMASK().
*
* @return: @__val masked and shifted into the field defined by @__mask.
*/
-#define REG_FIELD_PREP(__mask, __val) ((u32)FIELD_PREP(__mask, __val))
+#define REG_FIELD_PREP(__mask, __val) \
+ ((u32)((((typeof(__mask))(__val) << __bf_shf(__mask)) & (__mask)) + \
+ BUILD_BUG_ON_ZERO(!__builtin_constant_p(__mask)) + \
+ BUILD_BUG_ON_ZERO((__mask) == 0 || (__mask) > U32_MAX) + \
+ BUILD_BUG_ON_ZERO(!IS_POWER_OF_2((__mask) + (1ULL << __bf_shf(__mask)))) + \
+ BUILD_BUG_ON_ZERO(__builtin_choose_expr(__builtin_constant_p(__val), (~((__mask) >> __bf_shf(__mask)) & (__val)), 0))))
/**
* REG_FIELD_GET() - Extract a u32 bitfield value
@@ -4764,27 +4774,26 @@ enum {
*/
#define PP_READY REG_BIT(30)
#define PP_SEQUENCE_MASK REG_GENMASK(29, 28)
-#define PP_SEQUENCE_NONE (0 << 28)
-#define PP_SEQUENCE_POWER_UP (1 << 28)
-#define PP_SEQUENCE_POWER_DOWN (2 << 28)
+#define PP_SEQUENCE_NONE REG_FIELD_PREP(PP_SEQUENCE_MASK, 0)
+#define PP_SEQUENCE_POWER_UP REG_FIELD_PREP(PP_SEQUENCE_MASK, 1)
+#define PP_SEQUENCE_POWER_DOWN REG_FIELD_PREP(PP_SEQUENCE_MASK, 2)
#define PP_CYCLE_DELAY_ACTIVE REG_BIT(27)
#define PP_SEQUENCE_STATE_MASK REG_GENMASK(3, 0)
-#define PP_SEQUENCE_STATE_OFF_IDLE (0x0 << 0)
-#define PP_SEQUENCE_STATE_OFF_S0_1 (0x1 << 0)
-#define PP_SEQUENCE_STATE_OFF_S0_2 (0x2 << 0)
-#define PP_SEQUENCE_STATE_OFF_S0_3 (0x3 << 0)
-#define PP_SEQUENCE_STATE_ON_IDLE (0x8 << 0)
-#define PP_SEQUENCE_STATE_ON_S1_1 (0x9 << 0)
-#define PP_SEQUENCE_STATE_ON_S1_2 (0xa << 0)
-#define PP_SEQUENCE_STATE_ON_S1_3 (0xb << 0)
-#define PP_SEQUENCE_STATE_RESET (0xf << 0)
+#define PP_SEQUENCE_STATE_OFF_IDLE REG_FIELD_PREP(PP_SEQUENCE_STATE_MASK, 0x0)
+#define PP_SEQUENCE_STATE_OFF_S0_1 REG_FIELD_PREP(PP_SEQUENCE_STATE_MASK, 0x1)
+#define PP_SEQUENCE_STATE_OFF_S0_2 REG_FIELD_PREP(PP_SEQUENCE_STATE_MASK, 0x2)
+#define PP_SEQUENCE_STATE_OFF_S0_3 REG_FIELD_PREP(PP_SEQUENCE_STATE_MASK, 0x3)
+#define PP_SEQUENCE_STATE_ON_IDLE REG_FIELD_PREP(PP_SEQUENCE_STATE_MASK, 0x8)
+#define PP_SEQUENCE_STATE_ON_S1_1 REG_FIELD_PREP(PP_SEQUENCE_STATE_MASK, 0x9)
+#define PP_SEQUENCE_STATE_ON_S1_2 REG_FIELD_PREP(PP_SEQUENCE_STATE_MASK, 0xa)
+#define PP_SEQUENCE_STATE_ON_S1_3 REG_FIELD_PREP(PP_SEQUENCE_STATE_MASK, 0xb)
+#define PP_SEQUENCE_STATE_RESET REG_FIELD_PREP(PP_SEQUENCE_STATE_MASK, 0xf)
#define _PP_CONTROL 0x61204
#define PP_CONTROL(pps_idx) _MMIO_PPS(pps_idx, _PP_CONTROL)
#define PANEL_UNLOCK_MASK REG_GENMASK(31, 16)
-#define PANEL_UNLOCK_REGS (0xabcd << 16)
+#define PANEL_UNLOCK_REGS REG_FIELD_PREP(PANEL_UNLOCK_MASK, 0xabcd)
#define BXT_POWER_CYCLE_DELAY_MASK REG_GENMASK(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)
@@ -4793,11 +4802,11 @@ enum {
#define _PP_ON_DELAYS 0x61208
#define PP_ON_DELAYS(pps_idx) _MMIO_PPS(pps_idx, _PP_ON_DELAYS)
#define PANEL_PORT_SELECT_MASK REG_GENMASK(31, 30)
-#define PANEL_PORT_SELECT_LVDS (0 << 30)
-#define PANEL_PORT_SELECT_DPA (1 << 30)
-#define PANEL_PORT_SELECT_DPC (2 << 30)
-#define PANEL_PORT_SELECT_DPD (3 << 30)
-#define PANEL_PORT_SELECT_VLV(port) ((port) << 30)
+#define PANEL_PORT_SELECT_LVDS REG_FIELD_PREP(PANEL_PORT_SELECT_MASK, 0)
+#define PANEL_PORT_SELECT_DPA REG_FIELD_PREP(PANEL_PORT_SELECT_MASK, 1)
+#define PANEL_PORT_SELECT_DPC REG_FIELD_PREP(PANEL_PORT_SELECT_MASK, 2)
+#define PANEL_PORT_SELECT_DPD REG_FIELD_PREP(PANEL_PORT_SELECT_MASK, 3)
+#define PANEL_PORT_SELECT_VLV(port) REG_FIELD_PREP(PANEL_PORT_SELECT_MASK, port)
#define PANEL_POWER_UP_DELAY_MASK REG_GENMASK(28, 16)
#define PANEL_LIGHT_ON_DELAY_MASK REG_GENMASK(12, 0)
--
2.20.1
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
