| /* SPDX-License-Identifier: GPL-2.0-or-later */ |
| /* |
| * O32 interface for the 64 (or N32) ABI. |
| * |
| * Copyright (C) 2002, 2014 Maciej W. Rozycki |
| */ |
| |
| #include <asm/asm.h> |
| #include <asm/regdef.h> |
| |
| /* O32 register size. */ |
| #define O32_SZREG 4 |
| /* Maximum number of arguments supported. Must be even! */ |
| #define O32_ARGC 32 |
| /* Number of static registers we save. */ |
| #define O32_STATC 11 |
| /* Argument area frame size. */ |
| #define O32_ARGSZ (O32_SZREG * O32_ARGC) |
| /* Static register save area frame size. */ |
| #define O32_STATSZ (SZREG * O32_STATC) |
| /* Stack pointer register save area frame size. */ |
| #define O32_SPSZ SZREG |
| /* Combined area frame size. */ |
| #define O32_FRAMESZ (O32_ARGSZ + O32_SPSZ + O32_STATSZ) |
| /* Switched stack frame size. */ |
| #define O32_NFRAMESZ (O32_ARGSZ + O32_SPSZ) |
| |
| .text |
| |
| /* |
| * O32 function call dispatcher, for interfacing 32-bit ROM routines. |
| * |
| * The standard 64 (N32) calling sequence is supported, with a0 holding |
| * a function pointer, a1 a pointer to the new stack to call the |
| * function with or 0 if no stack switching is requested, a2-a7 -- the |
| * function call's first six arguments, and the stack -- the remaining |
| * arguments (up to O32_ARGC, including a2-a7). Static registers, gp |
| * and fp are preserved, v0 holds the result. This code relies on the |
| * called o32 function for sp and ra restoration and this dispatcher has |
| * to be placed in a KSEGx (or KUSEG) address space. Any pointers |
| * passed have to point to addresses within one of these spaces as well. |
| */ |
| NESTED(call_o32, O32_FRAMESZ, ra) |
| REG_SUBU sp,O32_FRAMESZ |
| |
| REG_S ra,O32_FRAMESZ-1*SZREG(sp) |
| REG_S fp,O32_FRAMESZ-2*SZREG(sp) |
| REG_S gp,O32_FRAMESZ-3*SZREG(sp) |
| REG_S s7,O32_FRAMESZ-4*SZREG(sp) |
| REG_S s6,O32_FRAMESZ-5*SZREG(sp) |
| REG_S s5,O32_FRAMESZ-6*SZREG(sp) |
| REG_S s4,O32_FRAMESZ-7*SZREG(sp) |
| REG_S s3,O32_FRAMESZ-8*SZREG(sp) |
| REG_S s2,O32_FRAMESZ-9*SZREG(sp) |
| REG_S s1,O32_FRAMESZ-10*SZREG(sp) |
| REG_S s0,O32_FRAMESZ-11*SZREG(sp) |
| |
| move jp,a0 |
| |
| move fp,sp |
| beqz a1,0f |
| REG_SUBU fp,a1,O32_NFRAMESZ |
| 0: |
| REG_S sp,O32_NFRAMESZ-1*SZREG(fp) |
| |
| sll a0,a2,zero |
| sll a1,a3,zero |
| sll a2,a4,zero |
| sll a3,a5,zero |
| sw a6,4*O32_SZREG(fp) |
| sw a7,5*O32_SZREG(fp) |
| |
| PTR_LA t0,O32_FRAMESZ(sp) |
| PTR_LA t1,6*O32_SZREG(fp) |
| li t2,O32_ARGC-6 |
| 1: |
| lw t3,(t0) |
| REG_ADDU t0,SZREG |
| sw t3,(t1) |
| REG_SUBU t2,1 |
| REG_ADDU t1,O32_SZREG |
| bnez t2,1b |
| |
| move sp,fp |
| |
| jalr jp |
| |
| REG_L sp,O32_NFRAMESZ-1*SZREG(sp) |
| |
| REG_L s0,O32_FRAMESZ-11*SZREG(sp) |
| REG_L s1,O32_FRAMESZ-10*SZREG(sp) |
| REG_L s2,O32_FRAMESZ-9*SZREG(sp) |
| REG_L s3,O32_FRAMESZ-8*SZREG(sp) |
| REG_L s4,O32_FRAMESZ-7*SZREG(sp) |
| REG_L s5,O32_FRAMESZ-6*SZREG(sp) |
| REG_L s6,O32_FRAMESZ-5*SZREG(sp) |
| REG_L s7,O32_FRAMESZ-4*SZREG(sp) |
| REG_L gp,O32_FRAMESZ-3*SZREG(sp) |
| REG_L fp,O32_FRAMESZ-2*SZREG(sp) |
| REG_L ra,O32_FRAMESZ-1*SZREG(sp) |
| |
| REG_ADDU sp,O32_FRAMESZ |
| jr ra |
| END(call_o32) |
