linux/arch/powerpc/math-emu/math.c
James Yang cc7059b5ea powerpc/math-emu: Fix load/store indexed emulation
Load/store indexed instructions where the index register RA=R0, such
as "lfdx f1,0,r3", are not illegal.

Load/store indexed with update instructions where the index register
RA=R0, such as "lfdux f1,0,r3", are invalid, and, to be consistent
with existing math-emu behavior for other invalid instruction forms,
will signal as illegal.

Signed-off-by: James Yang <James.Yang@freescale.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-08-14 14:59:57 +10:00

461 lines
11 KiB
C

/*
* Copyright (C) 1999 Eddie C. Dost (ecd@atecom.com)
*/
#include <linux/types.h>
#include <linux/sched.h>
#include <asm/uaccess.h>
#include <asm/reg.h>
#include <asm/switch_to.h>
#include <asm/sfp-machine.h>
#include <math-emu/double.h>
#define FLOATFUNC(x) extern int x(void *, void *, void *, void *)
/* The instructions list which may be not implemented by a hardware FPU */
FLOATFUNC(fre);
FLOATFUNC(frsqrtes);
FLOATFUNC(fsqrt);
FLOATFUNC(fsqrts);
FLOATFUNC(mtfsf);
FLOATFUNC(mtfsfi);
#ifdef CONFIG_MATH_EMULATION_HW_UNIMPLEMENTED
#undef FLOATFUNC(x)
#define FLOATFUNC(x) static inline int x(void *op1, void *op2, void *op3, \
void *op4) { }
#endif
FLOATFUNC(fadd);
FLOATFUNC(fadds);
FLOATFUNC(fdiv);
FLOATFUNC(fdivs);
FLOATFUNC(fmul);
FLOATFUNC(fmuls);
FLOATFUNC(fsub);
FLOATFUNC(fsubs);
FLOATFUNC(fmadd);
FLOATFUNC(fmadds);
FLOATFUNC(fmsub);
FLOATFUNC(fmsubs);
FLOATFUNC(fnmadd);
FLOATFUNC(fnmadds);
FLOATFUNC(fnmsub);
FLOATFUNC(fnmsubs);
FLOATFUNC(fctiw);
FLOATFUNC(fctiwz);
FLOATFUNC(frsp);
FLOATFUNC(fcmpo);
FLOATFUNC(fcmpu);
FLOATFUNC(mcrfs);
FLOATFUNC(mffs);
FLOATFUNC(mtfsb0);
FLOATFUNC(mtfsb1);
FLOATFUNC(lfd);
FLOATFUNC(lfs);
FLOATFUNC(stfd);
FLOATFUNC(stfs);
FLOATFUNC(stfiwx);
FLOATFUNC(fabs);
FLOATFUNC(fmr);
FLOATFUNC(fnabs);
FLOATFUNC(fneg);
/* Optional */
FLOATFUNC(fres);
FLOATFUNC(frsqrte);
FLOATFUNC(fsel);
#define OP31 0x1f /* 31 */
#define LFS 0x30 /* 48 */
#define LFSU 0x31 /* 49 */
#define LFD 0x32 /* 50 */
#define LFDU 0x33 /* 51 */
#define STFS 0x34 /* 52 */
#define STFSU 0x35 /* 53 */
#define STFD 0x36 /* 54 */
#define STFDU 0x37 /* 55 */
#define OP59 0x3b /* 59 */
#define OP63 0x3f /* 63 */
/* Opcode 31: */
/* X-Form: */
#define LFSX 0x217 /* 535 */
#define LFSUX 0x237 /* 567 */
#define LFDX 0x257 /* 599 */
#define LFDUX 0x277 /* 631 */
#define STFSX 0x297 /* 663 */
#define STFSUX 0x2b7 /* 695 */
#define STFDX 0x2d7 /* 727 */
#define STFDUX 0x2f7 /* 759 */
#define STFIWX 0x3d7 /* 983 */
/* Opcode 59: */
/* A-Form: */
#define FDIVS 0x012 /* 18 */
#define FSUBS 0x014 /* 20 */
#define FADDS 0x015 /* 21 */
#define FSQRTS 0x016 /* 22 */
#define FRES 0x018 /* 24 */
#define FMULS 0x019 /* 25 */
#define FRSQRTES 0x01a /* 26 */
#define FMSUBS 0x01c /* 28 */
#define FMADDS 0x01d /* 29 */
#define FNMSUBS 0x01e /* 30 */
#define FNMADDS 0x01f /* 31 */
/* Opcode 63: */
/* A-Form: */
#define FDIV 0x012 /* 18 */
#define FSUB 0x014 /* 20 */
#define FADD 0x015 /* 21 */
#define FSQRT 0x016 /* 22 */
#define FSEL 0x017 /* 23 */
#define FRE 0x018 /* 24 */
#define FMUL 0x019 /* 25 */
#define FRSQRTE 0x01a /* 26 */
#define FMSUB 0x01c /* 28 */
#define FMADD 0x01d /* 29 */
#define FNMSUB 0x01e /* 30 */
#define FNMADD 0x01f /* 31 */
/* X-Form: */
#define FCMPU 0x000 /* 0 */
#define FRSP 0x00c /* 12 */
#define FCTIW 0x00e /* 14 */
#define FCTIWZ 0x00f /* 15 */
#define FCMPO 0x020 /* 32 */
#define MTFSB1 0x026 /* 38 */
#define FNEG 0x028 /* 40 */
#define MCRFS 0x040 /* 64 */
#define MTFSB0 0x046 /* 70 */
#define FMR 0x048 /* 72 */
#define MTFSFI 0x086 /* 134 */
#define FNABS 0x088 /* 136 */
#define FABS 0x108 /* 264 */
#define MFFS 0x247 /* 583 */
#define MTFSF 0x2c7 /* 711 */
#define AB 2
#define AC 3
#define ABC 4
#define D 5
#define DU 6
#define X 7
#define XA 8
#define XB 9
#define XCR 11
#define XCRB 12
#define XCRI 13
#define XCRL 16
#define XE 14
#define XEU 15
#define XFLB 10
static int
record_exception(struct pt_regs *regs, int eflag)
{
u32 fpscr;
fpscr = __FPU_FPSCR;
if (eflag) {
fpscr |= FPSCR_FX;
if (eflag & EFLAG_OVERFLOW)
fpscr |= FPSCR_OX;
if (eflag & EFLAG_UNDERFLOW)
fpscr |= FPSCR_UX;
if (eflag & EFLAG_DIVZERO)
fpscr |= FPSCR_ZX;
if (eflag & EFLAG_INEXACT)
fpscr |= FPSCR_XX;
if (eflag & EFLAG_INVALID)
fpscr |= FPSCR_VX;
if (eflag & EFLAG_VXSNAN)
fpscr |= FPSCR_VXSNAN;
if (eflag & EFLAG_VXISI)
fpscr |= FPSCR_VXISI;
if (eflag & EFLAG_VXIDI)
fpscr |= FPSCR_VXIDI;
if (eflag & EFLAG_VXZDZ)
fpscr |= FPSCR_VXZDZ;
if (eflag & EFLAG_VXIMZ)
fpscr |= FPSCR_VXIMZ;
if (eflag & EFLAG_VXVC)
fpscr |= FPSCR_VXVC;
if (eflag & EFLAG_VXSOFT)
fpscr |= FPSCR_VXSOFT;
if (eflag & EFLAG_VXSQRT)
fpscr |= FPSCR_VXSQRT;
if (eflag & EFLAG_VXCVI)
fpscr |= FPSCR_VXCVI;
}
// fpscr &= ~(FPSCR_VX);
if (fpscr & (FPSCR_VXSNAN | FPSCR_VXISI | FPSCR_VXIDI |
FPSCR_VXZDZ | FPSCR_VXIMZ | FPSCR_VXVC |
FPSCR_VXSOFT | FPSCR_VXSQRT | FPSCR_VXCVI))
fpscr |= FPSCR_VX;
fpscr &= ~(FPSCR_FEX);
if (((fpscr & FPSCR_VX) && (fpscr & FPSCR_VE)) ||
((fpscr & FPSCR_OX) && (fpscr & FPSCR_OE)) ||
((fpscr & FPSCR_UX) && (fpscr & FPSCR_UE)) ||
((fpscr & FPSCR_ZX) && (fpscr & FPSCR_ZE)) ||
((fpscr & FPSCR_XX) && (fpscr & FPSCR_XE)))
fpscr |= FPSCR_FEX;
__FPU_FPSCR = fpscr;
return (fpscr & FPSCR_FEX) ? 1 : 0;
}
int
do_mathemu(struct pt_regs *regs)
{
void *op0 = 0, *op1 = 0, *op2 = 0, *op3 = 0;
unsigned long pc = regs->nip;
signed short sdisp;
u32 insn = 0;
int idx = 0;
int (*func)(void *, void *, void *, void *);
int type = 0;
int eflag, trap;
if (get_user(insn, (u32 *)pc))
return -EFAULT;
switch (insn >> 26) {
case LFS: func = lfs; type = D; break;
case LFSU: func = lfs; type = DU; break;
case LFD: func = lfd; type = D; break;
case LFDU: func = lfd; type = DU; break;
case STFS: func = stfs; type = D; break;
case STFSU: func = stfs; type = DU; break;
case STFD: func = stfd; type = D; break;
case STFDU: func = stfd; type = DU; break;
case OP31:
switch ((insn >> 1) & 0x3ff) {
case LFSX: func = lfs; type = XE; break;
case LFSUX: func = lfs; type = XEU; break;
case LFDX: func = lfd; type = XE; break;
case LFDUX: func = lfd; type = XEU; break;
case STFSX: func = stfs; type = XE; break;
case STFSUX: func = stfs; type = XEU; break;
case STFDX: func = stfd; type = XE; break;
case STFDUX: func = stfd; type = XEU; break;
case STFIWX: func = stfiwx; type = XE; break;
default:
goto illegal;
}
break;
case OP59:
switch ((insn >> 1) & 0x1f) {
case FDIVS: func = fdivs; type = AB; break;
case FSUBS: func = fsubs; type = AB; break;
case FADDS: func = fadds; type = AB; break;
case FSQRTS: func = fsqrts; type = XB; break;
case FRES: func = fres; type = XB; break;
case FMULS: func = fmuls; type = AC; break;
case FRSQRTES: func = frsqrtes;type = XB; break;
case FMSUBS: func = fmsubs; type = ABC; break;
case FMADDS: func = fmadds; type = ABC; break;
case FNMSUBS: func = fnmsubs; type = ABC; break;
case FNMADDS: func = fnmadds; type = ABC; break;
default:
goto illegal;
}
break;
case OP63:
if (insn & 0x20) {
switch ((insn >> 1) & 0x1f) {
case FDIV: func = fdiv; type = AB; break;
case FSUB: func = fsub; type = AB; break;
case FADD: func = fadd; type = AB; break;
case FSQRT: func = fsqrt; type = XB; break;
case FRE: func = fre; type = XB; break;
case FSEL: func = fsel; type = ABC; break;
case FMUL: func = fmul; type = AC; break;
case FRSQRTE: func = frsqrte; type = XB; break;
case FMSUB: func = fmsub; type = ABC; break;
case FMADD: func = fmadd; type = ABC; break;
case FNMSUB: func = fnmsub; type = ABC; break;
case FNMADD: func = fnmadd; type = ABC; break;
default:
goto illegal;
}
break;
}
switch ((insn >> 1) & 0x3ff) {
case FCMPU: func = fcmpu; type = XCR; break;
case FRSP: func = frsp; type = XB; break;
case FCTIW: func = fctiw; type = XB; break;
case FCTIWZ: func = fctiwz; type = XB; break;
case FCMPO: func = fcmpo; type = XCR; break;
case MTFSB1: func = mtfsb1; type = XCRB; break;
case FNEG: func = fneg; type = XB; break;
case MCRFS: func = mcrfs; type = XCRL; break;
case MTFSB0: func = mtfsb0; type = XCRB; break;
case FMR: func = fmr; type = XB; break;
case MTFSFI: func = mtfsfi; type = XCRI; break;
case FNABS: func = fnabs; type = XB; break;
case FABS: func = fabs; type = XB; break;
case MFFS: func = mffs; type = X; break;
case MTFSF: func = mtfsf; type = XFLB; break;
default:
goto illegal;
}
break;
default:
goto illegal;
}
switch (type) {
case AB:
op0 = (void *)&current->thread.TS_FPR((insn >> 21) & 0x1f);
op1 = (void *)&current->thread.TS_FPR((insn >> 16) & 0x1f);
op2 = (void *)&current->thread.TS_FPR((insn >> 11) & 0x1f);
break;
case AC:
op0 = (void *)&current->thread.TS_FPR((insn >> 21) & 0x1f);
op1 = (void *)&current->thread.TS_FPR((insn >> 16) & 0x1f);
op2 = (void *)&current->thread.TS_FPR((insn >> 6) & 0x1f);
break;
case ABC:
op0 = (void *)&current->thread.TS_FPR((insn >> 21) & 0x1f);
op1 = (void *)&current->thread.TS_FPR((insn >> 16) & 0x1f);
op2 = (void *)&current->thread.TS_FPR((insn >> 11) & 0x1f);
op3 = (void *)&current->thread.TS_FPR((insn >> 6) & 0x1f);
break;
case D:
idx = (insn >> 16) & 0x1f;
sdisp = (insn & 0xffff);
op0 = (void *)&current->thread.TS_FPR((insn >> 21) & 0x1f);
op1 = (void *)((idx ? regs->gpr[idx] : 0) + sdisp);
break;
case DU:
idx = (insn >> 16) & 0x1f;
if (!idx)
goto illegal;
sdisp = (insn & 0xffff);
op0 = (void *)&current->thread.TS_FPR((insn >> 21) & 0x1f);
op1 = (void *)(regs->gpr[idx] + sdisp);
break;
case X:
op0 = (void *)&current->thread.TS_FPR((insn >> 21) & 0x1f);
break;
case XA:
op0 = (void *)&current->thread.TS_FPR((insn >> 21) & 0x1f);
op1 = (void *)&current->thread.TS_FPR((insn >> 16) & 0x1f);
break;
case XB:
op0 = (void *)&current->thread.TS_FPR((insn >> 21) & 0x1f);
op1 = (void *)&current->thread.TS_FPR((insn >> 11) & 0x1f);
break;
case XE:
idx = (insn >> 16) & 0x1f;
op0 = (void *)&current->thread.TS_FPR((insn >> 21) & 0x1f);
op1 = (void *)((idx ? regs->gpr[idx] : 0)
+ regs->gpr[(insn >> 11) & 0x1f]);
break;
case XEU:
idx = (insn >> 16) & 0x1f;
if (!idx)
goto illegal;
op0 = (void *)&current->thread.TS_FPR((insn >> 21) & 0x1f);
op1 = (void *)(regs->gpr[idx]
+ regs->gpr[(insn >> 11) & 0x1f]);
break;
case XCR:
op0 = (void *)&regs->ccr;
op1 = (void *)((insn >> 23) & 0x7);
op2 = (void *)&current->thread.TS_FPR((insn >> 16) & 0x1f);
op3 = (void *)&current->thread.TS_FPR((insn >> 11) & 0x1f);
break;
case XCRL:
op0 = (void *)&regs->ccr;
op1 = (void *)((insn >> 23) & 0x7);
op2 = (void *)((insn >> 18) & 0x7);
break;
case XCRB:
op0 = (void *)((insn >> 21) & 0x1f);
break;
case XCRI:
op0 = (void *)((insn >> 23) & 0x7);
op1 = (void *)((insn >> 12) & 0xf);
break;
case XFLB:
op0 = (void *)((insn >> 17) & 0xff);
op1 = (void *)&current->thread.TS_FPR((insn >> 11) & 0x1f);
break;
default:
goto illegal;
}
/*
* If we support a HW FPU, we need to ensure the FP state
* is flushed into the thread_struct before attempting
* emulation
*/
flush_fp_to_thread(current);
eflag = func(op0, op1, op2, op3);
if (insn & 1) {
regs->ccr &= ~(0x0f000000);
regs->ccr |= (__FPU_FPSCR >> 4) & 0x0f000000;
}
trap = record_exception(regs, eflag);
if (trap)
return 1;
switch (type) {
case DU:
case XEU:
regs->gpr[idx] = (unsigned long)op1;
break;
default:
break;
}
regs->nip += 4;
return 0;
illegal:
return -ENOSYS;
}