| /* | |
| * Save/restore floating point context for signal handlers. | |
| * | |
| * This file is subject to the terms and conditions of the GNU General Public | |
| * License. See the file "COPYING" in the main directory of this archive | |
| * for more details. | |
| * | |
| * Copyright (C) 1999, 2000 Kaz Kojima & Niibe Yutaka | |
| * Copyright (C) 2006 ST Microelectronics Ltd. (denorm support) | |
| * | |
| * FIXME! These routines have not been tested for big endian case. | |
| */ | |
| #include <linux/sched.h> | |
| #include <linux/signal.h> | |
| #include <linux/io.h> | |
| #include <cpu/fpu.h> | |
| #include <asm/processor.h> | |
| #include <asm/fpu.h> | |
| #include <asm/traps.h> | |
| /* The PR (precision) bit in the FP Status Register must be clear when | |
| * an frchg instruction is executed, otherwise the instruction is undefined. | |
| * Executing frchg with PR set causes a trap on some SH4 implementations. | |
| */ | |
| #define FPSCR_RCHG 0x00000000 | |
| extern unsigned long long float64_div(unsigned long long a, | |
| unsigned long long b); | |
| extern unsigned long int float32_div(unsigned long int a, unsigned long int b); | |
| extern unsigned long long float64_mul(unsigned long long a, | |
| unsigned long long b); | |
| extern unsigned long int float32_mul(unsigned long int a, unsigned long int b); | |
| extern unsigned long long float64_add(unsigned long long a, | |
| unsigned long long b); | |
| extern unsigned long int float32_add(unsigned long int a, unsigned long int b); | |
| extern unsigned long long float64_sub(unsigned long long a, | |
| unsigned long long b); | |
| extern unsigned long int float32_sub(unsigned long int a, unsigned long int b); | |
| extern unsigned long int float64_to_float32(unsigned long long a); | |
| static unsigned int fpu_exception_flags; | |
| /* | |
| * Save FPU registers onto task structure. | |
| */ | |
| void save_fpu(struct task_struct *tsk) | |
| { | |
| unsigned long dummy; | |
| enable_fpu(); | |
| asm volatile ("sts.l fpul, @-%0\n\t" | |
| "sts.l fpscr, @-%0\n\t" | |
| "lds %2, fpscr\n\t" | |
| "frchg\n\t" | |
| "fmov.s fr15, @-%0\n\t" | |
| "fmov.s fr14, @-%0\n\t" | |
| "fmov.s fr13, @-%0\n\t" | |
| "fmov.s fr12, @-%0\n\t" | |
| "fmov.s fr11, @-%0\n\t" | |
| "fmov.s fr10, @-%0\n\t" | |
| "fmov.s fr9, @-%0\n\t" | |
| "fmov.s fr8, @-%0\n\t" | |
| "fmov.s fr7, @-%0\n\t" | |
| "fmov.s fr6, @-%0\n\t" | |
| "fmov.s fr5, @-%0\n\t" | |
| "fmov.s fr4, @-%0\n\t" | |
| "fmov.s fr3, @-%0\n\t" | |
| "fmov.s fr2, @-%0\n\t" | |
| "fmov.s fr1, @-%0\n\t" | |
| "fmov.s fr0, @-%0\n\t" | |
| "frchg\n\t" | |
| "fmov.s fr15, @-%0\n\t" | |
| "fmov.s fr14, @-%0\n\t" | |
| "fmov.s fr13, @-%0\n\t" | |
| "fmov.s fr12, @-%0\n\t" | |
| "fmov.s fr11, @-%0\n\t" | |
| "fmov.s fr10, @-%0\n\t" | |
| "fmov.s fr9, @-%0\n\t" | |
| "fmov.s fr8, @-%0\n\t" | |
| "fmov.s fr7, @-%0\n\t" | |
| "fmov.s fr6, @-%0\n\t" | |
| "fmov.s fr5, @-%0\n\t" | |
| "fmov.s fr4, @-%0\n\t" | |
| "fmov.s fr3, @-%0\n\t" | |
| "fmov.s fr2, @-%0\n\t" | |
| "fmov.s fr1, @-%0\n\t" | |
| "fmov.s fr0, @-%0\n\t" | |
| "lds %3, fpscr\n\t":"=r" (dummy) | |
| :"0"((char *)(&tsk->thread.xstate->hardfpu.status)), | |
| "r"(FPSCR_RCHG), "r"(FPSCR_INIT) | |
| :"memory"); | |
| disable_fpu(); | |
| } | |
| void restore_fpu(struct task_struct *tsk) | |
| { | |
| unsigned long dummy; | |
| enable_fpu(); | |
| asm volatile ("lds %2, fpscr\n\t" | |
| "fmov.s @%0+, fr0\n\t" | |
| "fmov.s @%0+, fr1\n\t" | |
| "fmov.s @%0+, fr2\n\t" | |
| "fmov.s @%0+, fr3\n\t" | |
| "fmov.s @%0+, fr4\n\t" | |
| "fmov.s @%0+, fr5\n\t" | |
| "fmov.s @%0+, fr6\n\t" | |
| "fmov.s @%0+, fr7\n\t" | |
| "fmov.s @%0+, fr8\n\t" | |
| "fmov.s @%0+, fr9\n\t" | |
| "fmov.s @%0+, fr10\n\t" | |
| "fmov.s @%0+, fr11\n\t" | |
| "fmov.s @%0+, fr12\n\t" | |
| "fmov.s @%0+, fr13\n\t" | |
| "fmov.s @%0+, fr14\n\t" | |
| "fmov.s @%0+, fr15\n\t" | |
| "frchg\n\t" | |
| "fmov.s @%0+, fr0\n\t" | |
| "fmov.s @%0+, fr1\n\t" | |
| "fmov.s @%0+, fr2\n\t" | |
| "fmov.s @%0+, fr3\n\t" | |
| "fmov.s @%0+, fr4\n\t" | |
| "fmov.s @%0+, fr5\n\t" | |
| "fmov.s @%0+, fr6\n\t" | |
| "fmov.s @%0+, fr7\n\t" | |
| "fmov.s @%0+, fr8\n\t" | |
| "fmov.s @%0+, fr9\n\t" | |
| "fmov.s @%0+, fr10\n\t" | |
| "fmov.s @%0+, fr11\n\t" | |
| "fmov.s @%0+, fr12\n\t" | |
| "fmov.s @%0+, fr13\n\t" | |
| "fmov.s @%0+, fr14\n\t" | |
| "fmov.s @%0+, fr15\n\t" | |
| "frchg\n\t" | |
| "lds.l @%0+, fpscr\n\t" | |
| "lds.l @%0+, fpul\n\t" | |
| :"=r" (dummy) | |
| :"0" (tsk->thread.xstate), "r" (FPSCR_RCHG) | |
| :"memory"); | |
| disable_fpu(); | |
| } | |
| /** | |
| * denormal_to_double - Given denormalized float number, | |
| * store double float | |
| * | |
| * @fpu: Pointer to sh_fpu_hard structure | |
| * @n: Index to FP register | |
| */ | |
| static void denormal_to_double(struct sh_fpu_hard_struct *fpu, int n) | |
| { | |
| unsigned long du, dl; | |
| unsigned long x = fpu->fpul; | |
| int exp = 1023 - 126; | |
| if (x != 0 && (x & 0x7f800000) == 0) { | |
| du = (x & 0x80000000); | |
| while ((x & 0x00800000) == 0) { | |
| x <<= 1; | |
| exp--; | |
| } | |
| x &= 0x007fffff; | |
| du |= (exp << 20) | (x >> 3); | |
| dl = x << 29; | |
| fpu->fp_regs[n] = du; | |
| fpu->fp_regs[n + 1] = dl; | |
| } | |
| } | |
| /** | |
| * ieee_fpe_handler - Handle denormalized number exception | |
| * | |
| * @regs: Pointer to register structure | |
| * | |
| * Returns 1 when it's handled (should not cause exception). | |
| */ | |
| static int ieee_fpe_handler(struct pt_regs *regs) | |
| { | |
| unsigned short insn = *(unsigned short *)regs->pc; | |
| unsigned short finsn; | |
| unsigned long nextpc; | |
| int nib[4] = { | |
| (insn >> 12) & 0xf, | |
| (insn >> 8) & 0xf, | |
| (insn >> 4) & 0xf, | |
| insn & 0xf | |
| }; | |
| if (nib[0] == 0xb || (nib[0] == 0x4 && nib[2] == 0x0 && nib[3] == 0xb)) | |
| regs->pr = regs->pc + 4; /* bsr & jsr */ | |
| if (nib[0] == 0xa || nib[0] == 0xb) { | |
| /* bra & bsr */ | |
| nextpc = regs->pc + 4 + ((short)((insn & 0xfff) << 4) >> 3); | |
| finsn = *(unsigned short *)(regs->pc + 2); | |
| } else if (nib[0] == 0x8 && nib[1] == 0xd) { | |
| /* bt/s */ | |
| if (regs->sr & 1) | |
| nextpc = regs->pc + 4 + ((char)(insn & 0xff) << 1); | |
| else | |
| nextpc = regs->pc + 4; | |
| finsn = *(unsigned short *)(regs->pc + 2); | |
| } else if (nib[0] == 0x8 && nib[1] == 0xf) { | |
| /* bf/s */ | |
| if (regs->sr & 1) | |
| nextpc = regs->pc + 4; | |
| else | |
| nextpc = regs->pc + 4 + ((char)(insn & 0xff) << 1); | |
| finsn = *(unsigned short *)(regs->pc + 2); | |
| } else if (nib[0] == 0x4 && nib[3] == 0xb && | |
| (nib[2] == 0x0 || nib[2] == 0x2)) { | |
| /* jmp & jsr */ | |
| nextpc = regs->regs[nib[1]]; | |
| finsn = *(unsigned short *)(regs->pc + 2); | |
| } else if (nib[0] == 0x0 && nib[3] == 0x3 && | |
| (nib[2] == 0x0 || nib[2] == 0x2)) { | |
| /* braf & bsrf */ | |
| nextpc = regs->pc + 4 + regs->regs[nib[1]]; | |
| finsn = *(unsigned short *)(regs->pc + 2); | |
| } else if (insn == 0x000b) { | |
| /* rts */ | |
| nextpc = regs->pr; | |
| finsn = *(unsigned short *)(regs->pc + 2); | |
| } else { | |
| nextpc = regs->pc + instruction_size(insn); | |
| finsn = insn; | |
| } | |
| if ((finsn & 0xf1ff) == 0xf0ad) { | |
| /* fcnvsd */ | |
| struct task_struct *tsk = current; | |
| if ((tsk->thread.xstate->hardfpu.fpscr & FPSCR_CAUSE_ERROR)) | |
| /* FPU error */ | |
| denormal_to_double(&tsk->thread.xstate->hardfpu, | |
| (finsn >> 8) & 0xf); | |
| else | |
| return 0; | |
| regs->pc = nextpc; | |
| return 1; | |
| } else if ((finsn & 0xf00f) == 0xf002) { | |
| /* fmul */ | |
| struct task_struct *tsk = current; | |
| int fpscr; | |
| int n, m, prec; | |
| unsigned int hx, hy; | |
| n = (finsn >> 8) & 0xf; | |
| m = (finsn >> 4) & 0xf; | |
| hx = tsk->thread.xstate->hardfpu.fp_regs[n]; | |
| hy = tsk->thread.xstate->hardfpu.fp_regs[m]; | |
| fpscr = tsk->thread.xstate->hardfpu.fpscr; | |
| prec = fpscr & FPSCR_DBL_PRECISION; | |
| if ((fpscr & FPSCR_CAUSE_ERROR) | |
| && (prec && ((hx & 0x7fffffff) < 0x00100000 | |
| || (hy & 0x7fffffff) < 0x00100000))) { | |
| long long llx, lly; | |
| /* FPU error because of denormal (doubles) */ | |
| llx = ((long long)hx << 32) | |
| | tsk->thread.xstate->hardfpu.fp_regs[n + 1]; | |
| lly = ((long long)hy << 32) | |
| | tsk->thread.xstate->hardfpu.fp_regs[m + 1]; | |
| llx = float64_mul(llx, lly); | |
| tsk->thread.xstate->hardfpu.fp_regs[n] = llx >> 32; | |
| tsk->thread.xstate->hardfpu.fp_regs[n + 1] = llx & 0xffffffff; | |
| } else if ((fpscr & FPSCR_CAUSE_ERROR) | |
| && (!prec && ((hx & 0x7fffffff) < 0x00800000 | |
| || (hy & 0x7fffffff) < 0x00800000))) { | |
| /* FPU error because of denormal (floats) */ | |
| hx = float32_mul(hx, hy); | |
| tsk->thread.xstate->hardfpu.fp_regs[n] = hx; | |
| } else | |
| return 0; | |
| regs->pc = nextpc; | |
| return 1; | |
| } else if ((finsn & 0xf00e) == 0xf000) { | |
| /* fadd, fsub */ | |
| struct task_struct *tsk = current; | |
| int fpscr; | |
| int n, m, prec; | |
| unsigned int hx, hy; | |
| n = (finsn >> 8) & 0xf; | |
| m = (finsn >> 4) & 0xf; | |
| hx = tsk->thread.xstate->hardfpu.fp_regs[n]; | |
| hy = tsk->thread.xstate->hardfpu.fp_regs[m]; | |
| fpscr = tsk->thread.xstate->hardfpu.fpscr; | |
| prec = fpscr & FPSCR_DBL_PRECISION; | |
| if ((fpscr & FPSCR_CAUSE_ERROR) | |
| && (prec && ((hx & 0x7fffffff) < 0x00100000 | |
| || (hy & 0x7fffffff) < 0x00100000))) { | |
| long long llx, lly; | |
| /* FPU error because of denormal (doubles) */ | |
| llx = ((long long)hx << 32) | |
| | tsk->thread.xstate->hardfpu.fp_regs[n + 1]; | |
| lly = ((long long)hy << 32) | |
| | tsk->thread.xstate->hardfpu.fp_regs[m + 1]; | |
| if ((finsn & 0xf00f) == 0xf000) | |
| llx = float64_add(llx, lly); | |
| else | |
| llx = float64_sub(llx, lly); | |
| tsk->thread.xstate->hardfpu.fp_regs[n] = llx >> 32; | |
| tsk->thread.xstate->hardfpu.fp_regs[n + 1] = llx & 0xffffffff; | |
| } else if ((fpscr & FPSCR_CAUSE_ERROR) | |
| && (!prec && ((hx & 0x7fffffff) < 0x00800000 | |
| || (hy & 0x7fffffff) < 0x00800000))) { | |
| /* FPU error because of denormal (floats) */ | |
| if ((finsn & 0xf00f) == 0xf000) | |
| hx = float32_add(hx, hy); | |
| else | |
| hx = float32_sub(hx, hy); | |
| tsk->thread.xstate->hardfpu.fp_regs[n] = hx; | |
| } else | |
| return 0; | |
| regs->pc = nextpc; | |
| return 1; | |
| } else if ((finsn & 0xf003) == 0xf003) { | |
| /* fdiv */ | |
| struct task_struct *tsk = current; | |
| int fpscr; | |
| int n, m, prec; | |
| unsigned int hx, hy; | |
| n = (finsn >> 8) & 0xf; | |
| m = (finsn >> 4) & 0xf; | |
| hx = tsk->thread.xstate->hardfpu.fp_regs[n]; | |
| hy = tsk->thread.xstate->hardfpu.fp_regs[m]; | |
| fpscr = tsk->thread.xstate->hardfpu.fpscr; | |
| prec = fpscr & FPSCR_DBL_PRECISION; | |
| if ((fpscr & FPSCR_CAUSE_ERROR) | |
| && (prec && ((hx & 0x7fffffff) < 0x00100000 | |
| || (hy & 0x7fffffff) < 0x00100000))) { | |
| long long llx, lly; | |
| /* FPU error because of denormal (doubles) */ | |
| llx = ((long long)hx << 32) | |
| | tsk->thread.xstate->hardfpu.fp_regs[n + 1]; | |
| lly = ((long long)hy << 32) | |
| | tsk->thread.xstate->hardfpu.fp_regs[m + 1]; | |
| llx = float64_div(llx, lly); | |
| tsk->thread.xstate->hardfpu.fp_regs[n] = llx >> 32; | |
| tsk->thread.xstate->hardfpu.fp_regs[n + 1] = llx & 0xffffffff; | |
| } else if ((fpscr & FPSCR_CAUSE_ERROR) | |
| && (!prec && ((hx & 0x7fffffff) < 0x00800000 | |
| || (hy & 0x7fffffff) < 0x00800000))) { | |
| /* FPU error because of denormal (floats) */ | |
| hx = float32_div(hx, hy); | |
| tsk->thread.xstate->hardfpu.fp_regs[n] = hx; | |
| } else | |
| return 0; | |
| regs->pc = nextpc; | |
| return 1; | |
| } else if ((finsn & 0xf0bd) == 0xf0bd) { | |
| /* fcnvds - double to single precision convert */ | |
| struct task_struct *tsk = current; | |
| int m; | |
| unsigned int hx; | |
| m = (finsn >> 8) & 0x7; | |
| hx = tsk->thread.xstate->hardfpu.fp_regs[m]; | |
| if ((tsk->thread.xstate->hardfpu.fpscr & FPSCR_CAUSE_ERROR) | |
| && ((hx & 0x7fffffff) < 0x00100000)) { | |
| /* subnormal double to float conversion */ | |
| long long llx; | |
| llx = ((long long)tsk->thread.xstate->hardfpu.fp_regs[m] << 32) | |
| | tsk->thread.xstate->hardfpu.fp_regs[m + 1]; | |
| tsk->thread.xstate->hardfpu.fpul = float64_to_float32(llx); | |
| } else | |
| return 0; | |
| regs->pc = nextpc; | |
| return 1; | |
| } | |
| return 0; | |
| } | |
| void float_raise(unsigned int flags) | |
| { | |
| fpu_exception_flags |= flags; | |
| } | |
| int float_rounding_mode(void) | |
| { | |
| struct task_struct *tsk = current; | |
| int roundingMode = FPSCR_ROUNDING_MODE(tsk->thread.xstate->hardfpu.fpscr); | |
| return roundingMode; | |
| } | |
| BUILD_TRAP_HANDLER(fpu_error) | |
| { | |
| struct task_struct *tsk = current; | |
| TRAP_HANDLER_DECL; | |
| __unlazy_fpu(tsk, regs); | |
| fpu_exception_flags = 0; | |
| if (ieee_fpe_handler(regs)) { | |
| tsk->thread.xstate->hardfpu.fpscr &= | |
| ~(FPSCR_CAUSE_MASK | FPSCR_FLAG_MASK); | |
| tsk->thread.xstate->hardfpu.fpscr |= fpu_exception_flags; | |
| /* Set the FPSCR flag as well as cause bits - simply | |
| * replicate the cause */ | |
| tsk->thread.xstate->hardfpu.fpscr |= (fpu_exception_flags >> 10); | |
| grab_fpu(regs); | |
| restore_fpu(tsk); | |
| task_thread_info(tsk)->status |= TS_USEDFPU; | |
| if ((((tsk->thread.xstate->hardfpu.fpscr & FPSCR_ENABLE_MASK) >> 7) & | |
| (fpu_exception_flags >> 2)) == 0) { | |
| return; | |
| } | |
| } | |
| force_sig(SIGFPE, tsk); | |
| } |