1*3c35731bSJani Nikula /* SPDX-License-Identifier: MIT */ 2*3c35731bSJani Nikula /* Copyright © 2026 Intel Corporation */ 3*3c35731bSJani Nikula 4*3c35731bSJani Nikula #ifndef _PICK_H_ 5*3c35731bSJani Nikula #define _PICK_H_ 6*3c35731bSJani Nikula 7*3c35731bSJani Nikula /* 8*3c35731bSJani Nikula * Given the first two numbers __a and __b of arbitrarily many evenly spaced 9*3c35731bSJani Nikula * numbers, pick the 0-based __index'th value. 10*3c35731bSJani Nikula * 11*3c35731bSJani Nikula * Always prefer this over _PICK() if the numbers are evenly spaced. 12*3c35731bSJani Nikula */ 13*3c35731bSJani Nikula #define _PICK_EVEN(__index, __a, __b) ((__a) + (__index) * ((__b) - (__a))) 14*3c35731bSJani Nikula 15*3c35731bSJani Nikula /* 16*3c35731bSJani Nikula * Like _PICK_EVEN(), but supports 2 ranges of evenly spaced address offsets. 17*3c35731bSJani Nikula * @__c_index corresponds to the index in which the second range starts to be 18*3c35731bSJani Nikula * used. Using math interval notation, the first range is used for indexes [ 0, 19*3c35731bSJani Nikula * @__c_index), while the second range is used for [ @__c_index, ... ). Example: 20*3c35731bSJani Nikula * 21*3c35731bSJani Nikula * #define _FOO_A 0xf000 22*3c35731bSJani Nikula * #define _FOO_B 0xf004 23*3c35731bSJani Nikula * #define _FOO_C 0xf008 24*3c35731bSJani Nikula * #define _SUPER_FOO_A 0xa000 25*3c35731bSJani Nikula * #define _SUPER_FOO_B 0xa100 26*3c35731bSJani Nikula * #define FOO(x) _MMIO(_PICK_EVEN_2RANGES(x, 3, \ 27*3c35731bSJani Nikula * _FOO_A, _FOO_B, \ 28*3c35731bSJani Nikula * _SUPER_FOO_A, _SUPER_FOO_B)) 29*3c35731bSJani Nikula * 30*3c35731bSJani Nikula * This expands to: 31*3c35731bSJani Nikula * 0: 0xf000, 32*3c35731bSJani Nikula * 1: 0xf004, 33*3c35731bSJani Nikula * 2: 0xf008, 34*3c35731bSJani Nikula * 3: 0xa000, 35*3c35731bSJani Nikula * 4: 0xa100, 36*3c35731bSJani Nikula * 5: 0xa200, 37*3c35731bSJani Nikula * ... 38*3c35731bSJani Nikula */ 39*3c35731bSJani Nikula #define _PICK_EVEN_2RANGES(__index, __c_index, __a, __b, __c, __d) \ 40*3c35731bSJani Nikula (BUILD_BUG_ON_ZERO(!__is_constexpr(__c_index)) + \ 41*3c35731bSJani Nikula ((__index) < (__c_index) ? _PICK_EVEN(__index, __a, __b) : \ 42*3c35731bSJani Nikula _PICK_EVEN((__index) - (__c_index), __c, __d))) 43*3c35731bSJani Nikula 44*3c35731bSJani Nikula /* 45*3c35731bSJani Nikula * Given the arbitrary numbers in varargs, pick the 0-based __index'th number. 46*3c35731bSJani Nikula * 47*3c35731bSJani Nikula * Always prefer _PICK_EVEN() over this if the numbers are evenly spaced. 48*3c35731bSJani Nikula */ 49*3c35731bSJani Nikula #define _PICK(__index, ...) (((const u32 []){ __VA_ARGS__ })[__index]) 50*3c35731bSJani Nikula 51*3c35731bSJani Nikula #endif 52