--- /dev/null
+/*
+ * arch/sh/math-emu/math.c
+ *
+ * Copyright (C) 2006 Takashi YOSHII <takasi-y@ops.dti.ne.jp>
+ *
+ * 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.
+ */
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/sched.h>
+#include <linux/signal.h>
+
+#include <asm/system.h>
+#include <asm/uaccess.h>
+#include <asm/processor.h>
+#include <asm/io.h>
+
+#include "sfp-util.h"
+#include <math-emu/soft-fp.h>
+#include <math-emu/single.h>
+#include <math-emu/double.h>
+
+#define FPUL (fregs->fpul)
+#define FPSCR (fregs->fpscr)
+#define FPSCR_RM (FPSCR&3)
+#define FPSCR_DN ((FPSCR>>18)&1)
+#define FPSCR_PR ((FPSCR>>19)&1)
+#define FPSCR_SZ ((FPSCR>>20)&1)
+#define FPSCR_FR ((FPSCR>>21)&1)
+#define FPSCR_MASK 0x003fffffUL
+
+#define BANK(n) (n^(FPSCR_FR?16:0))
+#define FR ((unsigned long*)(fregs->fp_regs))
+#define FR0 (FR[BANK(0)])
+#define FRn (FR[BANK(n)])
+#define FRm (FR[BANK(m)])
+#define DR ((unsigned long long*)(fregs->fp_regs))
+#define DRn (DR[BANK(n)/2])
+#define DRm (DR[BANK(m)/2])
+
+#define XREG(n) (n^16)
+#define XFn (FR[BANK(XREG(n))])
+#define XFm (FR[BANK(XREG(m))])
+#define XDn (DR[BANK(XREG(n))/2])
+#define XDm (DR[BANK(XREG(m))/2])
+
+#define R0 (regs->regs[0])
+#define Rn (regs->regs[n])
+#define Rm (regs->regs[m])
+
+#define WRITE(d,a) ({if(put_user(d, (typeof (d)*)a)) return -EFAULT;})
+#define READ(d,a) ({if(get_user(d, (typeof (d)*)a)) return -EFAULT;})
+
+#define PACK_S(r,f) FP_PACK_SP(&r,f)
+#define UNPACK_S(f,r) FP_UNPACK_SP(f,&r)
+#define PACK_D(r,f) \
+ {u32 t[2]; FP_PACK_DP(t,f); ((u32*)&r)[0]=t[1]; ((u32*)&r)[1]=t[0];}
+#define UNPACK_D(f,r) \
+ {u32 t[2]; t[0]=((u32*)&r)[1]; t[1]=((u32*)&r)[0]; FP_UNPACK_DP(f,t);}
+
+// 2 args instructions.
+#define BOTH_PRmn(op,x) \
+ FP_DECL_EX; if(FPSCR_PR) op(D,x,DRm,DRn); else op(S,x,FRm,FRn);
+
+#define CMP_X(SZ,R,M,N) do{ \
+ FP_DECL_##SZ(Fm); FP_DECL_##SZ(Fn); \
+ UNPACK_##SZ(Fm, M); UNPACK_##SZ(Fn, N); \
+ FP_CMP_##SZ(R, Fn, Fm, 2); }while(0)
+#define EQ_X(SZ,R,M,N) do{ \
+ FP_DECL_##SZ(Fm); FP_DECL_##SZ(Fn); \
+ UNPACK_##SZ(Fm, M); UNPACK_##SZ(Fn, N); \
+ FP_CMP_EQ_##SZ(R, Fn, Fm); }while(0)
+#define CMP(OP) ({ int r; BOTH_PRmn(OP##_X,r); r; })
+
+static int
+fcmp_gt(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, int m, int n)
+{
+ if (CMP(CMP) > 0)
+ regs->sr |= 1;
+ else
+ regs->sr &= ~1;
+
+ return 0;
+}
+
+static int
+fcmp_eq(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, int m, int n)
+{
+ if (CMP(CMP /*EQ*/) == 0)
+ regs->sr |= 1;
+ else
+ regs->sr &= ~1;
+ return 0;
+}
+
+#define ARITH_X(SZ,OP,M,N) do{ \
+ FP_DECL_##SZ(Fm); FP_DECL_##SZ(Fn); FP_DECL_##SZ(Fr); \
+ UNPACK_##SZ(Fm, M); UNPACK_##SZ(Fn, N); \
+ FP_##OP##_##SZ(Fr, Fn, Fm); \
+ PACK_##SZ(N, Fr); }while(0)
+
+static int
+fadd(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, int m, int n)
+{
+ BOTH_PRmn(ARITH_X, ADD);
+ return 0;
+}
+
+static int
+fsub(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, int m, int n)
+{
+ BOTH_PRmn(ARITH_X, SUB);
+ return 0;
+}
+
+static int
+fmul(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, int m, int n)
+{
+ BOTH_PRmn(ARITH_X, MUL);
+ return 0;
+}
+
+static int
+fdiv(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, int m, int n)
+{
+ BOTH_PRmn(ARITH_X, DIV);
+ return 0;
+}
+
+static int
+fmac(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, int m, int n)
+{
+ FP_DECL_EX;
+ FP_DECL_S(Fr);
+ FP_DECL_S(Ft);
+ FP_DECL_S(F0);
+ FP_DECL_S(Fm);
+ FP_DECL_S(Fn);
+ UNPACK_S(F0, FR0);
+ UNPACK_S(Fm, FRm);
+ UNPACK_S(Fn, FRn);
+ FP_MUL_S(Ft, Fm, F0);
+ FP_ADD_S(Fr, Fn, Ft);
+ PACK_S(FRn, Fr);
+ return 0;
+}
+
+// to process fmov's extention (odd n for DR access XD).
+#define FMOV_EXT(x) if(x&1) x+=16-1
+
+static int
+fmov_idx_reg(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, int m,
+ int n)
+{
+ if (FPSCR_SZ) {
+ FMOV_EXT(n);
+ READ(FRn, Rm + R0 + 4);
+ n++;
+ READ(FRn, Rm + R0);
+ } else {
+ READ(FRn, Rm + R0);
+ }
+
+ return 0;
+}
+
+static int
+fmov_mem_reg(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, int m,
+ int n)
+{
+ if (FPSCR_SZ) {
+ FMOV_EXT(n);
+ READ(FRn, Rm + 4);
+ n++;
+ READ(FRn, Rm);
+ } else {
+ READ(FRn, Rm);
+ }
+
+ return 0;
+}
+
+static int
+fmov_inc_reg(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, int m,
+ int n)
+{
+ if (FPSCR_SZ) {
+ FMOV_EXT(n);
+ READ(FRn, Rm + 4);
+ n++;
+ READ(FRn, Rm);
+ Rm += 8;
+ } else {
+ READ(FRn, Rm);
+ Rm += 4;
+ }
+
+ return 0;
+}
+
+static int
+fmov_reg_idx(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, int m,
+ int n)
+{
+ if (FPSCR_SZ) {
+ FMOV_EXT(m);
+ WRITE(FRm, Rn + R0 + 4);
+ m++;
+ WRITE(FRm, Rn + R0);
+ } else {
+ WRITE(FRm, Rn + R0);
+ }
+
+ return 0;
+}
+
+static int
+fmov_reg_mem(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, int m,
+ int n)
+{
+ if (FPSCR_SZ) {
+ FMOV_EXT(m);
+ WRITE(FRm, Rn + 4);
+ m++;
+ WRITE(FRm, Rn);
+ } else {
+ WRITE(FRm, Rn);
+ }
+
+ return 0;
+}
+
+static int
+fmov_reg_dec(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, int m,
+ int n)
+{
+ if (FPSCR_SZ) {
+ FMOV_EXT(m);
+ Rn -= 8;
+ WRITE(FRm, Rn + 4);
+ m++;
+ WRITE(FRm, Rn);
+ } else {
+ Rn -= 4;
+ WRITE(FRm, Rn);
+ }
+
+ return 0;
+}
+
+static int
+fmov_reg_reg(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, int m,
+ int n)
+{
+ if (FPSCR_SZ) {
+ FMOV_EXT(m);
+ FMOV_EXT(n);
+ DRn = DRm;
+ } else {
+ FRn = FRm;
+ }
+
+ return 0;
+}
+
+static int
+fnop_mn(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, int m, int n)
+{
+ return -EINVAL;
+}
+
+// 1 arg instructions.
+#define NOTYETn(i) static int i(struct sh_fpu_soft_struct *fregs, int n) \
+ { printk( #i " not yet done.\n"); return 0; }
+
+NOTYETn(ftrv)
+NOTYETn(fsqrt)
+NOTYETn(fipr)
+NOTYETn(fsca)
+NOTYETn(fsrra)
+
+#define EMU_FLOAT_X(SZ,N) do { \
+ FP_DECL_##SZ(Fn); \
+ FP_FROM_INT_##SZ(Fn, FPUL, 32, int); \
+ PACK_##SZ(N, Fn); }while(0)
+static int ffloat(struct sh_fpu_soft_struct *fregs, int n)
+{
+ FP_DECL_EX;
+
+ if (FPSCR_PR)
+ EMU_FLOAT_X(D, DRn);
+ else
+ EMU_FLOAT_X(S, FRn);
+
+ return 0;
+}
+
+#define EMU_FTRC_X(SZ,N) do { \
+ FP_DECL_##SZ(Fn); \
+ UNPACK_##SZ(Fn, N); \
+ FP_TO_INT_##SZ(FPUL, Fn, 32, 1); }while(0)
+static int ftrc(struct sh_fpu_soft_struct *fregs, int n)
+{
+ FP_DECL_EX;
+
+ if (FPSCR_PR)
+ EMU_FTRC_X(D, DRn);
+ else
+ EMU_FTRC_X(S, FRn);
+
+ return 0;
+}
+
+static int fcnvsd(struct sh_fpu_soft_struct *fregs, int n)
+{
+ FP_DECL_EX;
+ FP_DECL_S(Fn);
+ FP_DECL_D(Fr);
+ UNPACK_S(Fn, FPUL);
+ FP_CONV(D, S, 2, 1, Fr, Fn);
+ PACK_D(DRn, Fr);
+ return 0;
+}
+
+static int fcnvds(struct sh_fpu_soft_struct *fregs, int n)
+{
+ FP_DECL_EX;
+ FP_DECL_D(Fn);
+ FP_DECL_S(Fr);
+ UNPACK_D(Fn, DRn);
+ FP_CONV(S, D, 1, 2, Fr, Fn);
+ PACK_S(FPUL, Fr);
+ return 0;
+}
+
+static int fxchg(struct sh_fpu_soft_struct *fregs, int flag)
+{
+ FPSCR ^= flag;
+ return 0;
+}
+
+static int fsts(struct sh_fpu_soft_struct *fregs, int n)
+{
+ FRn = FPUL;
+ return 0;
+}
+
+static int flds(struct sh_fpu_soft_struct *fregs, int n)
+{
+ FPUL = FRn;
+ return 0;
+}
+
+static int fneg(struct sh_fpu_soft_struct *fregs, int n)
+{
+ FRn ^= (1 << (_FP_W_TYPE_SIZE - 1));
+ return 0;
+}
+
+static int fabs(struct sh_fpu_soft_struct *fregs, int n)
+{
+ FRn &= ~(1 << (_FP_W_TYPE_SIZE - 1));
+ return 0;
+}
+
+static int fld0(struct sh_fpu_soft_struct *fregs, int n)
+{
+ FRn = 0;
+ return 0;
+}
+
+static int fld1(struct sh_fpu_soft_struct *fregs, int n)
+{
+ FRn = (_FP_EXPBIAS_S << (_FP_FRACBITS_S - 1));
+ return 0;
+}
+
+static int fnop_n(struct sh_fpu_soft_struct *fregs, int n)
+{
+ return -EINVAL;
+}
+
+/// Instruction decoders.
+
+static int id_fxfd(struct sh_fpu_soft_struct *, int);
+static int id_fnxd(struct sh_fpu_soft_struct *, struct pt_regs *, int, int);
+
+static int (*fnxd[])(struct sh_fpu_soft_struct *, int) = {
+ fsts, flds, ffloat, ftrc, fneg, fabs, fsqrt, fsrra,
+ fld0, fld1, fcnvsd, fcnvds, fnop_n, fnop_n, fipr, id_fxfd
+};
+
+static int (*fnmx[])(struct sh_fpu_soft_struct *, struct pt_regs *, int, int) = {
+ fadd, fsub, fmul, fdiv, fcmp_eq, fcmp_gt, fmov_idx_reg, fmov_reg_idx,
+ fmov_mem_reg, fmov_inc_reg, fmov_reg_mem, fmov_reg_dec,
+ fmov_reg_reg, id_fnxd, fmac, fnop_mn};
+
+static int id_fxfd(struct sh_fpu_soft_struct *fregs, int x)
+{
+ const int flag[] = { FPSCR_SZ, FPSCR_PR, FPSCR_FR, 0 };
+ switch (x & 3) {
+ case 3:
+ fxchg(fregs, flag[x >> 2]);
+ break;
+ case 1:
+ ftrv(fregs, x - 1);
+ break;
+ default:
+ fsca(fregs, x);
+ }
+ return 0;
+}
+
+static int
+id_fnxd(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, int x, int n)
+{
+ return (fnxd[x])(fregs, n);
+}
+
+static int
+id_fnmx(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, u16 code)
+{
+ int n = (code >> 8) & 0xf, m = (code >> 4) & 0xf, x = code & 0xf;
+ return (fnmx[x])(fregs, regs, m, n);
+}
+
+static int
+id_sys(struct sh_fpu_soft_struct *fregs, struct pt_regs *regs, u16 code)
+{
+ int n = ((code >> 8) & 0xf);
+ unsigned long *reg = (code & 0x0010) ? &FPUL : &FPSCR;
+
+ switch (code & 0xf0ff) {
+ case 0x005a:
+ case 0x006a:
+ Rn = *reg;
+ break;
+ case 0x405a:
+ case 0x406a:
+ *reg = Rn;
+ break;
+ case 0x4052:
+ case 0x4062:
+ Rn -= 4;
+ WRITE(*reg, Rn);
+ break;
+ case 0x4056:
+ case 0x4066:
+ READ(*reg, Rn);
+ Rn += 4;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int fpu_emulate(u16 code, struct sh_fpu_soft_struct *fregs, struct pt_regs *regs)
+{
+ if ((code & 0xf000) == 0xf000)
+ return id_fnmx(fregs, regs, code);
+ else
+ return id_sys(fregs, regs, code);
+}
+
+/**
+ * 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)) /* bsr & jsr */
+ regs->pr = regs->pc + 4;
+
+ 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 + 2;
+ finsn = insn;
+ }
+
+ if ((finsn & 0xf1ff) == 0xf0ad) { /* fcnvsd */
+ struct task_struct *tsk = current;
+
+ if ((tsk->thread.fpu.hard.fpscr & (1 << 17))) {
+ /* FPU error */
+ denormal_to_double (&tsk->thread.fpu.hard,
+ (finsn >> 8) & 0xf);
+ tsk->thread.fpu.hard.fpscr &=
+ ~(FPSCR_CAUSE_MASK | FPSCR_FLAG_MASK);
+ set_tsk_thread_flag(tsk, TIF_USEDFPU);
+ } else {
+ tsk->thread.trap_no = 11;
+ tsk->thread.error_code = 0;
+ force_sig(SIGFPE, tsk);
+ }
+
+ regs->pc = nextpc;
+ return 1;
+ }
+
+ return 0;
+}
+
+asmlinkage void do_fpu_error(unsigned long r4, unsigned long r5,
+ unsigned long r6, unsigned long r7,
+ struct pt_regs regs)
+{
+ struct task_struct *tsk = current;
+
+ if (ieee_fpe_handler (®s))
+ return;
+
+ regs.pc += 2;
+ tsk->thread.trap_no = 11;
+ tsk->thread.error_code = 0;
+ force_sig(SIGFPE, tsk);
+}
+
+/**
+ * fpu_init - Initialize FPU registers
+ * @fpu: Pointer to software emulated FPU registers.
+ */
+static void fpu_init(struct sh_fpu_soft_struct *fpu)
+{
+ int i;
+
+ fpu->fpscr = FPSCR_INIT;
+ fpu->fpul = 0;
+
+ for (i = 0; i < 16; i++) {
+ fpu->fp_regs[i] = 0;
+ fpu->xfp_regs[i]= 0;
+ }
+}
+
+/**
+ * do_fpu_inst - Handle reserved instructions for FPU emulation
+ * @inst: instruction code.
+ * @regs: registers on stack.
+ */
+int do_fpu_inst(unsigned short inst, struct pt_regs *regs)
+{
+ struct task_struct *tsk = current;
+ struct sh_fpu_soft_struct *fpu = &(tsk->thread.fpu.soft);
+
+ if (!test_tsk_thread_flag(tsk, TIF_USEDFPU)) {
+ /* initialize once. */
+ fpu_init(fpu);
+ set_tsk_thread_flag(tsk, TIF_USEDFPU);
+ }
+
+ return fpu_emulate(inst, fpu, regs);
+}
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