diff options
| -rw-r--r-- | drivers/gpu/drm/i915/i915_reg_defs.h | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_reg_defs.h b/drivers/gpu/drm/i915/i915_reg_defs.h index be43580a6979..983c5aa3045b 100644 --- a/drivers/gpu/drm/i915/i915_reg_defs.h +++ b/drivers/gpu/drm/i915/i915_reg_defs.h @@ -120,6 +120,35 @@ #define _PICK_EVEN(__index, __a, __b) ((__a) + (__index) * ((__b) - (__a))) /* + * Like _PICK_EVEN(), but supports 2 ranges of evenly spaced address offsets. + * @__c_index corresponds to the index in which the second range starts to be + * used. Using math interval notation, the first range is used for indexes [ 0, + * @__c_index), while the second range is used for [ @__c_index, ... ). Example: + * + * #define _FOO_A 0xf000 + * #define _FOO_B 0xf004 + * #define _FOO_C 0xf008 + * #define _SUPER_FOO_A 0xa000 + * #define _SUPER_FOO_B 0xa100 + * #define FOO(x) _MMIO(_PICK_EVEN_2RANGES(x, 3, \ + * _FOO_A, _FOO_B, \ + * _SUPER_FOO_A, _SUPER_FOO_B)) + * + * This expands to: + * 0: 0xf000, + * 1: 0xf004, + * 2: 0xf008, + * 3: 0xa000, + * 4: 0xa100, + * 5: 0xa200, + * ... + */ +#define _PICK_EVEN_2RANGES(__index, __c_index, __a, __b, __c, __d) \ + (BUILD_BUG_ON_ZERO(!__is_constexpr(__c_index)) + \ + ((__index) < (__c_index) ? _PICK_EVEN(__index, __a, __b) : \ + _PICK_EVEN((__index) - (__c_index), __c, __d))) + +/* * Given the arbitrary numbers in varargs, pick the 0-based __index'th number. * * Always prefer _PICK_EVEN() over this if the numbers are evenly spaced. |