From cd21dfcfbb5c43de54f6be795dde07397da2bc2f Mon Sep 17 00:00:00 2001 From: Ralf Baechle Date: Thu, 28 Apr 2005 13:39:10 +0000 Subject: [PATCH] Fix preemption and SMP problems in the FP emulator code. Signed-off-by: Ralf Baechle --- arch/mips/kernel/traps.c | 19 +++- arch/mips/math-emu/cp1emu.c | 41 +++++--- arch/mips/math-emu/dp_sqrt.c | 2 +- arch/mips/math-emu/ieee754.c | 4 - arch/mips/math-emu/ieee754.h | 175 +++++++++++++++-------------------- 5 files changed, 122 insertions(+), 119 deletions(-) diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c index 15fed02021..b3ecd02757 100644 --- a/arch/mips/kernel/traps.c +++ b/arch/mips/kernel/traps.c @@ -551,6 +551,14 @@ asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31) preempt_disable(); +#ifdef CONFIG_PREEMPT + if (!is_fpu_owner()) { + /* We might lose fpu before disabling preempt... */ + own_fpu(); + BUG_ON(!used_math()); + restore_fp(current); + } +#endif /* * Unimplemented operation exception. If we've got the full * software emulator on-board, let's use it... @@ -562,11 +570,18 @@ asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31) * a bit extreme for what should be an infrequent event. */ save_fp(current); + /* Ensure 'resume' not overwrite saved fp context again. */ + lose_fpu(); + + preempt_enable(); /* Run the emulator */ sig = fpu_emulator_cop1Handler (0, regs, ¤t->thread.fpu.soft); + preempt_disable(); + + own_fpu(); /* Using the FPU again. */ /* * We can't allow the emulated instruction to leave any of * the cause bit set in $fcr31. @@ -712,6 +727,8 @@ asmlinkage void do_cpu(struct pt_regs *regs) set_used_math(); } + preempt_enable(); + if (!cpu_has_fpu) { int sig = fpu_emulator_cop1Handler(0, regs, ¤t->thread.fpu.soft); @@ -719,8 +736,6 @@ asmlinkage void do_cpu(struct pt_regs *regs) force_sig(sig, current); } - preempt_enable(); - return; case 2: diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c index c70f25f588..6fed6ce43c 100644 --- a/arch/mips/math-emu/cp1emu.c +++ b/arch/mips/math-emu/cp1emu.c @@ -79,7 +79,17 @@ struct mips_fpu_emulator_private fpuemuprivate; /* Convert Mips rounding mode (0..3) to IEEE library modes. */ static const unsigned char ieee_rm[4] = { - IEEE754_RN, IEEE754_RZ, IEEE754_RU, IEEE754_RD + [FPU_CSR_RN] = IEEE754_RN, + [FPU_CSR_RZ] = IEEE754_RZ, + [FPU_CSR_RU] = IEEE754_RU, + [FPU_CSR_RD] = IEEE754_RD, +}; +/* Convert IEEE library modes to Mips rounding mode (0..3). */ +static const unsigned char mips_rm[4] = { + [IEEE754_RN] = FPU_CSR_RN, + [IEEE754_RZ] = FPU_CSR_RZ, + [IEEE754_RD] = FPU_CSR_RD, + [IEEE754_RU] = FPU_CSR_RU, }; #if __mips >= 4 @@ -368,6 +378,7 @@ static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_soft_struct *ctx) } if (MIPSInst_RD(ir) == FPCREG_CSR) { value = ctx->fcr31; + value = (value & ~0x3) | mips_rm[value & 0x3]; #ifdef CSRTRACE printk("%p gpr[%d]<-csr=%08x\n", (void *) (xcp->cp0_epc), @@ -400,11 +411,10 @@ static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_soft_struct *ctx) (void *) (xcp->cp0_epc), MIPSInst_RT(ir), value); #endif - ctx->fcr31 = value; - /* copy new rounding mode and - flush bit to ieee library state! */ - ieee754_csr.nod = (ctx->fcr31 & 0x1000000) != 0; - ieee754_csr.rm = ieee_rm[value & 0x3]; + value &= (FPU_CSR_FLUSH | FPU_CSR_ALL_E | FPU_CSR_ALL_S | 0x03); + ctx->fcr31 &= ~(FPU_CSR_FLUSH | FPU_CSR_ALL_E | FPU_CSR_ALL_S | 0x03); + /* convert to ieee library modes */ + ctx->fcr31 |= (value & ~0x3) | ieee_rm[value & 0x3]; } if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) { return SIGFPE; @@ -570,7 +580,7 @@ static const unsigned char cmptab[8] = { static ieee754##p fpemu_##p##_##name (ieee754##p r, ieee754##p s, \ ieee754##p t) \ { \ - struct ieee754_csr ieee754_csr_save; \ + struct _ieee754_csr ieee754_csr_save; \ s = f1 (s, t); \ ieee754_csr_save = ieee754_csr; \ s = f2 (s, r); \ @@ -699,8 +709,6 @@ static int fpux_emu(struct pt_regs *xcp, struct mips_fpu_soft_struct *ctx, rcsr |= FPU_CSR_INV_X | FPU_CSR_INV_S; ctx->fcr31 = (ctx->fcr31 & ~FPU_CSR_ALL_X) | rcsr; - if (ieee754_csr.nod) - ctx->fcr31 |= 0x1000000; if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) { /*printk ("SIGFPE: fpu csr = %08x\n", ctx->fcr31); */ @@ -1297,12 +1305,17 @@ int fpu_emulator_cop1Handler(int xcptno, struct pt_regs *xcp, if (insn == 0) xcp->cp0_epc += 4; /* skip nops */ else { - /* Update ieee754_csr. Only relevant if we have a - h/w FPU */ - ieee754_csr.nod = (ctx->fcr31 & 0x1000000) != 0; - ieee754_csr.rm = ieee_rm[ctx->fcr31 & 0x3]; - ieee754_csr.cx = (ctx->fcr31 >> 12) & 0x1f; + /* + * The 'ieee754_csr' is an alias of + * ctx->fcr31. No need to copy ctx->fcr31 to + * ieee754_csr. But ieee754_csr.rm is ieee + * library modes. (not mips rounding mode) + */ + /* convert to ieee library modes */ + ieee754_csr.rm = ieee_rm[ieee754_csr.rm]; sig = cop1Emulate(xcp, ctx); + /* revert to mips rounding mode */ + ieee754_csr.rm = mips_rm[ieee754_csr.rm]; } if (cpu_has_fpu) diff --git a/arch/mips/math-emu/dp_sqrt.c b/arch/mips/math-emu/dp_sqrt.c index c35e871ae9..032328c498 100644 --- a/arch/mips/math-emu/dp_sqrt.c +++ b/arch/mips/math-emu/dp_sqrt.c @@ -37,7 +37,7 @@ static const unsigned table[] = { ieee754dp ieee754dp_sqrt(ieee754dp x) { - struct ieee754_csr oldcsr; + struct _ieee754_csr oldcsr; ieee754dp y, z, t; unsigned scalx, yh; COMPXDP; diff --git a/arch/mips/math-emu/ieee754.c b/arch/mips/math-emu/ieee754.c index f0a364adbf..97a752fc30 100644 --- a/arch/mips/math-emu/ieee754.c +++ b/arch/mips/math-emu/ieee754.c @@ -50,10 +50,6 @@ const char *const ieee754_cname[] = { "SNaN", }; -/* the control status register -*/ -struct ieee754_csr ieee754_csr; - /* special constants */ diff --git a/arch/mips/math-emu/ieee754.h b/arch/mips/math-emu/ieee754.h index b8772f4697..5689b0cf01 100644 --- a/arch/mips/math-emu/ieee754.h +++ b/arch/mips/math-emu/ieee754.h @@ -1,13 +1,8 @@ -/* single and double precision fp ops - * missing extended precision. -*/ /* * MIPS floating point support * Copyright (C) 1994-2000 Algorithmics Ltd. * http://www.algor.co.uk * - * ######################################################################## - * * This program is free software; you can distribute it and/or modify it * under the terms of the GNU General Public License (Version 2) as * published by the Free Software Foundation. @@ -21,20 +16,16 @@ * with this program; if not, write to the Free Software Foundation, Inc., * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA. * - * ######################################################################## - */ - -/************************************************************************** * Nov 7, 2000 * Modification to allow integration with Linux kernel * * Kevin D. Kissell, kevink@mips.com and Carsten Langgard, carstenl@mips.com * Copyright (C) 2000 MIPS Technologies, Inc. All rights reserved. - *************************************************************************/ + */ -#ifdef __KERNEL__ -/* Going from Algorithmics to Linux native environment, add this */ +#include #include +#include /* * Not very pretty, but the Linux kernel's normal va_list definition @@ -44,18 +35,7 @@ #include #endif -#else - -/* Note that __KERNEL__ is taken to mean Linux kernel */ - -#if #system(OpenBSD) -#include -#endif -#include - -#endif /* __KERNEL__ */ - -#if (defined(BYTE_ORDER) && BYTE_ORDER == LITTLE_ENDIAN) || defined(__MIPSEL__) +#ifdef __LITTLE_ENDIAN struct ieee754dp_konst { unsigned mantlo:32; unsigned manthi:20; @@ -86,13 +66,14 @@ typedef union _ieee754sp { } ieee754sp; #endif -#if (defined(BYTE_ORDER) && BYTE_ORDER == BIG_ENDIAN) || defined(__MIPSEB__) +#ifdef __BIG_ENDIAN struct ieee754dp_konst { unsigned sign:1; unsigned bexp:11; unsigned manthi:20; unsigned mantlo:32; }; + typedef union _ieee754dp { struct ieee754dp_konst oparts; struct { @@ -251,93 +232,109 @@ extern const char *const ieee754_cname[]; /* "normal" comparisons */ -static __inline int ieee754sp_eq(ieee754sp x, ieee754sp y) +static inline int ieee754sp_eq(ieee754sp x, ieee754sp y) { return ieee754sp_cmp(x, y, IEEE754_CEQ, 0); } -static __inline int ieee754sp_ne(ieee754sp x, ieee754sp y) +static inline int ieee754sp_ne(ieee754sp x, ieee754sp y) { return ieee754sp_cmp(x, y, IEEE754_CLT | IEEE754_CGT | IEEE754_CUN, 0); } -static __inline int ieee754sp_lt(ieee754sp x, ieee754sp y) +static inline int ieee754sp_lt(ieee754sp x, ieee754sp y) { return ieee754sp_cmp(x, y, IEEE754_CLT, 0); } -static __inline int ieee754sp_le(ieee754sp x, ieee754sp y) +static inline int ieee754sp_le(ieee754sp x, ieee754sp y) { return ieee754sp_cmp(x, y, IEEE754_CLT | IEEE754_CEQ, 0); } -static __inline int ieee754sp_gt(ieee754sp x, ieee754sp y) +static inline int ieee754sp_gt(ieee754sp x, ieee754sp y) { return ieee754sp_cmp(x, y, IEEE754_CGT, 0); } -static __inline int ieee754sp_ge(ieee754sp x, ieee754sp y) +static inline int ieee754sp_ge(ieee754sp x, ieee754sp y) { return ieee754sp_cmp(x, y, IEEE754_CGT | IEEE754_CEQ, 0); } -static __inline int ieee754dp_eq(ieee754dp x, ieee754dp y) +static inline int ieee754dp_eq(ieee754dp x, ieee754dp y) { return ieee754dp_cmp(x, y, IEEE754_CEQ, 0); } -static __inline int ieee754dp_ne(ieee754dp x, ieee754dp y) +static inline int ieee754dp_ne(ieee754dp x, ieee754dp y) { return ieee754dp_cmp(x, y, IEEE754_CLT | IEEE754_CGT | IEEE754_CUN, 0); } -static __inline int ieee754dp_lt(ieee754dp x, ieee754dp y) +static inline int ieee754dp_lt(ieee754dp x, ieee754dp y) { return ieee754dp_cmp(x, y, IEEE754_CLT, 0); } -static __inline int ieee754dp_le(ieee754dp x, ieee754dp y) +static inline int ieee754dp_le(ieee754dp x, ieee754dp y) { return ieee754dp_cmp(x, y, IEEE754_CLT | IEEE754_CEQ, 0); } -static __inline int ieee754dp_gt(ieee754dp x, ieee754dp y) +static inline int ieee754dp_gt(ieee754dp x, ieee754dp y) { return ieee754dp_cmp(x, y, IEEE754_CGT, 0); } -static __inline int ieee754dp_ge(ieee754dp x, ieee754dp y) +static inline int ieee754dp_ge(ieee754dp x, ieee754dp y) { return ieee754dp_cmp(x, y, IEEE754_CGT | IEEE754_CEQ, 0); } -/* like strtod -*/ +/* + * Like strtod + */ ieee754dp ieee754dp_fstr(const char *s, char **endp); char *ieee754dp_tstr(ieee754dp x, int prec, int fmt, int af); -/* the control status register -*/ -struct ieee754_csr { - unsigned pad:13; +/* + * The control status register + */ +struct _ieee754_csr { +#ifdef __BIG_ENDIAN + unsigned pad0:7; unsigned nod:1; /* set 1 for no denormalised numbers */ - unsigned cx:5; /* exceptions this operation */ + unsigned c:1; /* condition */ + unsigned pad1:5; + unsigned cx:6; /* exceptions this operation */ unsigned mx:5; /* exception enable mask */ unsigned sx:5; /* exceptions total */ unsigned rm:2; /* current rounding mode */ +#endif +#ifdef __LITTLE_ENDIAN + unsigned rm:2; /* current rounding mode */ + unsigned sx:5; /* exceptions total */ + unsigned mx:5; /* exception enable mask */ + unsigned cx:6; /* exceptions this operation */ + unsigned pad1:5; + unsigned c:1; /* condition */ + unsigned nod:1; /* set 1 for no denormalised numbers */ + unsigned pad0:7; +#endif }; -extern struct ieee754_csr ieee754_csr; +#define ieee754_csr (*(struct _ieee754_csr *)(¤t->thread.fpu.soft.fcr31)) -static __inline unsigned ieee754_getrm(void) +static inline unsigned ieee754_getrm(void) { return (ieee754_csr.rm); } -static __inline unsigned ieee754_setrm(unsigned rm) +static inline unsigned ieee754_setrm(unsigned rm) { return (ieee754_csr.rm = rm); } @@ -345,14 +342,14 @@ static __inline unsigned ieee754_setrm(unsigned rm) /* * get current exceptions */ -static __inline unsigned ieee754_getcx(void) +static inline unsigned ieee754_getcx(void) { return (ieee754_csr.cx); } /* test for current exception condition */ -static __inline int ieee754_cxtest(unsigned n) +static inline int ieee754_cxtest(unsigned n) { return (ieee754_csr.cx & n); } @@ -360,21 +357,21 @@ static __inline int ieee754_cxtest(unsigned n) /* * get sticky exceptions */ -static __inline unsigned ieee754_getsx(void) +static inline unsigned ieee754_getsx(void) { return (ieee754_csr.sx); } /* clear sticky conditions */ -static __inline unsigned ieee754_clrsx(void) +static inline unsigned ieee754_clrsx(void) { return (ieee754_csr.sx = 0); } /* test for sticky exception condition */ -static __inline int ieee754_sxtest(unsigned n) +static inline int ieee754_sxtest(unsigned n) { return (ieee754_csr.sx & n); } @@ -406,52 +403,34 @@ extern const struct ieee754sp_konst __ieee754sp_spcvals[]; #define ieee754dp_spcvals ((const ieee754dp *)__ieee754dp_spcvals) #define ieee754sp_spcvals ((const ieee754sp *)__ieee754sp_spcvals) -/* return infinity with given sign -*/ -#define ieee754dp_inf(sn) \ - (ieee754dp_spcvals[IEEE754_SPCVAL_PINFINITY+(sn)]) -#define ieee754dp_zero(sn) \ - (ieee754dp_spcvals[IEEE754_SPCVAL_PZERO+(sn)]) -#define ieee754dp_one(sn) \ - (ieee754dp_spcvals[IEEE754_SPCVAL_PONE+(sn)]) -#define ieee754dp_ten(sn) \ - (ieee754dp_spcvals[IEEE754_SPCVAL_PTEN+(sn)]) -#define ieee754dp_indef() \ - (ieee754dp_spcvals[IEEE754_SPCVAL_INDEF]) -#define ieee754dp_max(sn) \ - (ieee754dp_spcvals[IEEE754_SPCVAL_PMAX+(sn)]) -#define ieee754dp_min(sn) \ - (ieee754dp_spcvals[IEEE754_SPCVAL_PMIN+(sn)]) -#define ieee754dp_mind(sn) \ - (ieee754dp_spcvals[IEEE754_SPCVAL_PMIND+(sn)]) -#define ieee754dp_1e31() \ - (ieee754dp_spcvals[IEEE754_SPCVAL_P1E31]) -#define ieee754dp_1e63() \ - (ieee754dp_spcvals[IEEE754_SPCVAL_P1E63]) - -#define ieee754sp_inf(sn) \ - (ieee754sp_spcvals[IEEE754_SPCVAL_PINFINITY+(sn)]) -#define ieee754sp_zero(sn) \ - (ieee754sp_spcvals[IEEE754_SPCVAL_PZERO+(sn)]) -#define ieee754sp_one(sn) \ - (ieee754sp_spcvals[IEEE754_SPCVAL_PONE+(sn)]) -#define ieee754sp_ten(sn) \ - (ieee754sp_spcvals[IEEE754_SPCVAL_PTEN+(sn)]) -#define ieee754sp_indef() \ - (ieee754sp_spcvals[IEEE754_SPCVAL_INDEF]) -#define ieee754sp_max(sn) \ - (ieee754sp_spcvals[IEEE754_SPCVAL_PMAX+(sn)]) -#define ieee754sp_min(sn) \ - (ieee754sp_spcvals[IEEE754_SPCVAL_PMIN+(sn)]) -#define ieee754sp_mind(sn) \ - (ieee754sp_spcvals[IEEE754_SPCVAL_PMIND+(sn)]) -#define ieee754sp_1e31() \ - (ieee754sp_spcvals[IEEE754_SPCVAL_P1E31]) -#define ieee754sp_1e63() \ - (ieee754sp_spcvals[IEEE754_SPCVAL_P1E63]) - -/* indefinite integer value -*/ +/* + * Return infinity with given sign + */ +#define ieee754dp_inf(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PINFINITY+(sn)]) +#define ieee754dp_zero(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PZERO+(sn)]) +#define ieee754dp_one(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PONE+(sn)]) +#define ieee754dp_ten(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PTEN+(sn)]) +#define ieee754dp_indef() (ieee754dp_spcvals[IEEE754_SPCVAL_INDEF]) +#define ieee754dp_max(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PMAX+(sn)]) +#define ieee754dp_min(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PMIN+(sn)]) +#define ieee754dp_mind(sn) (ieee754dp_spcvals[IEEE754_SPCVAL_PMIND+(sn)]) +#define ieee754dp_1e31() (ieee754dp_spcvals[IEEE754_SPCVAL_P1E31]) +#define ieee754dp_1e63() (ieee754dp_spcvals[IEEE754_SPCVAL_P1E63]) + +#define ieee754sp_inf(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PINFINITY+(sn)]) +#define ieee754sp_zero(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PZERO+(sn)]) +#define ieee754sp_one(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PONE+(sn)]) +#define ieee754sp_ten(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PTEN+(sn)]) +#define ieee754sp_indef() (ieee754sp_spcvals[IEEE754_SPCVAL_INDEF]) +#define ieee754sp_max(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PMAX+(sn)]) +#define ieee754sp_min(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PMIN+(sn)]) +#define ieee754sp_mind(sn) (ieee754sp_spcvals[IEEE754_SPCVAL_PMIND+(sn)]) +#define ieee754sp_1e31() (ieee754sp_spcvals[IEEE754_SPCVAL_P1E31]) +#define ieee754sp_1e63() (ieee754sp_spcvals[IEEE754_SPCVAL_P1E63]) + +/* + * Indefinite integer value + */ #define ieee754si_indef() INT_MAX #ifdef LONG_LONG_MAX #define ieee754di_indef() LONG_LONG_MAX -- 2.39.5