diff options
Diffstat (limited to 'arch/mips')
| -rw-r--r-- | arch/mips/include/asm/mipsregs.h | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/arch/mips/include/asm/mipsregs.h b/arch/mips/include/asm/mipsregs.h index 7a59ad6..ac70613 100644 --- a/arch/mips/include/asm/mipsregs.h +++ b/arch/mips/include/asm/mipsregs.h @@ -1181,6 +1181,89 @@ static inline int mm_insn_16bit(u16 insn) #endif /* + * parse_r var, r - Helper assembler macro for parsing register names. + * + * This converts the register name in $n form provided in \r to the + * corresponding register number, which is assigned to the variable \var. It is + * needed to allow explicit encoding of instructions in inline assembly where + * registers are chosen by the compiler in $n form, allowing us to avoid using + * fixed register numbers. + * + * It also allows newer instructions (not implemented by the assembler) to be + * transparently implemented using assembler macros, instead of needing separate + * cases depending on toolchain support. + * + * Simple usage example: + * __asm__ __volatile__("parse_r __rt, %0\n\t" + * ".insn\n\t" + * "# di %0\n\t" + * ".word (0x41606000 | (__rt << 16))" + * : "=r" (status); + */ + +/* Match an individual register number and assign to \var */ +#define _IFC_REG(n) \ + ".ifc \\r, $" #n "\n\t" \ + "\\var = " #n "\n\t" \ + ".endif\n\t" + +__asm__(".macro parse_r var r\n\t" + "\\var = -1\n\t" + _IFC_REG(0) _IFC_REG(1) _IFC_REG(2) _IFC_REG(3) + _IFC_REG(4) _IFC_REG(5) _IFC_REG(6) _IFC_REG(7) + _IFC_REG(8) _IFC_REG(9) _IFC_REG(10) _IFC_REG(11) + _IFC_REG(12) _IFC_REG(13) _IFC_REG(14) _IFC_REG(15) + _IFC_REG(16) _IFC_REG(17) _IFC_REG(18) _IFC_REG(19) + _IFC_REG(20) _IFC_REG(21) _IFC_REG(22) _IFC_REG(23) + _IFC_REG(24) _IFC_REG(25) _IFC_REG(26) _IFC_REG(27) + _IFC_REG(28) _IFC_REG(29) _IFC_REG(30) _IFC_REG(31) + ".iflt \\var\n\t" + ".error \"Unable to parse register name \\r\"\n\t" + ".endif\n\t" + ".endm"); + +#undef _IFC_REG + +/* + * C macros for generating assembler macros for common instruction formats. + * + * The names of the operands can be chosen by the caller, and the encoding of + * register operand \<Rn> is assigned to __<Rn> where it can be accessed from + * the ENC encodings. + */ + +/* Instructions with no operands */ +#define _ASM_MACRO_0(OP, ENC) \ + __asm__(".macro " #OP "\n\t" \ + ENC \ + ".endm") + +/* Instructions with 2 register operands */ +#define _ASM_MACRO_2R(OP, R1, R2, ENC) \ + __asm__(".macro " #OP " " #R1 ", " #R2 "\n\t" \ + "parse_r __" #R1 ", \\" #R1 "\n\t" \ + "parse_r __" #R2 ", \\" #R2 "\n\t" \ + ENC \ + ".endm") + +/* Instructions with 3 register operands */ +#define _ASM_MACRO_3R(OP, R1, R2, R3, ENC) \ + __asm__(".macro " #OP " " #R1 ", " #R2 ", " #R3 "\n\t" \ + "parse_r __" #R1 ", \\" #R1 "\n\t" \ + "parse_r __" #R2 ", \\" #R2 "\n\t" \ + "parse_r __" #R3 ", \\" #R3 "\n\t" \ + ENC \ + ".endm") + +/* Instructions with 2 register operands and 1 optional select operand */ +#define _ASM_MACRO_2R_1S(OP, R1, R2, SEL3, ENC) \ + __asm__(".macro " #OP " " #R1 ", " #R2 ", " #SEL3 " = 0\n\t" \ + "parse_r __" #R1 ", \\" #R1 "\n\t" \ + "parse_r __" #R2 ", \\" #R2 "\n\t" \ + ENC \ + ".endm") + +/* * TLB Invalidate Flush */ static inline void tlbinvf(void) |
