diff --git a/arch/mips/include/asm/cpu-info.h b/arch/mips/include/asm/cpu-info.h index c3f4f2d2e108..e7dc785a91ca 100644 --- a/arch/mips/include/asm/cpu-info.h +++ b/arch/mips/include/asm/cpu-info.h @@ -49,6 +49,8 @@ struct cpuinfo_mips { unsigned int udelay_val; unsigned int processor_id; unsigned int fpu_id; + unsigned int fpu_csr31; + unsigned int fpu_msk31; unsigned int msa_id; unsigned int cputype; int isa_level; diff --git a/arch/mips/include/asm/elf.h b/arch/mips/include/asm/elf.h index 535f196ffe02..612cf519bd88 100644 --- a/arch/mips/include/asm/elf.h +++ b/arch/mips/include/asm/elf.h @@ -11,6 +11,9 @@ #include #include +#include +#include + /* ELF header e_flags defines. */ /* MIPS architecture level. */ #define EF_MIPS_ARCH_1 0x00000000 /* -mips1 code. */ @@ -297,6 +300,8 @@ do { \ mips_set_personality_fp(state); \ \ current->thread.abi = &mips_abi; \ + \ + current->thread.fpu.fcr31 = current_cpu_data.fpu_csr31; \ } while (0) #endif /* CONFIG_32BIT */ @@ -356,6 +361,8 @@ do { \ else \ current->thread.abi = &mips_abi; \ \ + current->thread.fpu.fcr31 = current_cpu_data.fpu_csr31; \ + \ p = personality(current->personality); \ if (p != PER_LINUX32 && p != PER_LINUX) \ set_personality(PER_LINUX); \ diff --git a/arch/mips/include/asm/fpu.h b/arch/mips/include/asm/fpu.h index dd083e999b08..83d50d563a0f 100644 --- a/arch/mips/include/asm/fpu.h +++ b/arch/mips/include/asm/fpu.h @@ -30,7 +30,7 @@ struct sigcontext; struct sigcontext32; -extern void _init_fpu(void); +extern void _init_fpu(unsigned int); extern void _save_fp(struct task_struct *); extern void _restore_fp(struct task_struct *); @@ -182,6 +182,7 @@ static inline void lose_fpu(int save) static inline int init_fpu(void) { + unsigned int fcr31 = current->thread.fpu.fcr31; int ret = 0; if (cpu_has_fpu) { @@ -192,7 +193,7 @@ static inline int init_fpu(void) return ret; if (!cpu_has_fre) { - _init_fpu(); + _init_fpu(fcr31); return 0; } @@ -206,7 +207,7 @@ static inline int init_fpu(void) config5 = clear_c0_config5(MIPS_CONF5_FRE); enable_fpu_hazard(); - _init_fpu(); + _init_fpu(fcr31); /* Restore FRE */ write_c0_config5(config5); diff --git a/arch/mips/include/asm/fpu_emulator.h b/arch/mips/include/asm/fpu_emulator.h index bfcc5c64b7b0..2f021cdfba4f 100644 --- a/arch/mips/include/asm/fpu_emulator.h +++ b/arch/mips/include/asm/fpu_emulator.h @@ -88,8 +88,6 @@ static inline void fpu_emulator_init_fpu(void) struct task_struct *t = current; int i; - t->thread.fpu.fcr31 = 0; - for (i = 0; i < 32; i++) set_fpr64(&t->thread.fpu.fpr[i], 0, SIGNALLING_NAN); } diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c index ca9b9c62c6ea..2911ad5977d7 100644 --- a/arch/mips/kernel/cpu-probe.c +++ b/arch/mips/kernel/cpu-probe.c @@ -32,6 +32,35 @@ #include #include +/* + * Determine the FCSR mask for FPU hardware. + */ +static inline void cpu_set_fpu_fcsr_mask(struct cpuinfo_mips *c) +{ + unsigned long sr, mask, fcsr, fcsr0, fcsr1; + + mask = FPU_CSR_ALL_X | FPU_CSR_ALL_E | FPU_CSR_ALL_S | FPU_CSR_RM; + + sr = read_c0_status(); + __enable_fpu(FPU_AS_IS); + + fcsr = read_32bit_cp1_register(CP1_STATUS); + + fcsr0 = fcsr & mask; + write_32bit_cp1_register(CP1_STATUS, fcsr0); + fcsr0 = read_32bit_cp1_register(CP1_STATUS); + + fcsr1 = fcsr | ~mask; + write_32bit_cp1_register(CP1_STATUS, fcsr1); + fcsr1 = read_32bit_cp1_register(CP1_STATUS); + + write_32bit_cp1_register(CP1_STATUS, fcsr); + + write_c0_status(sr); + + c->fpu_msk31 = ~(fcsr0 ^ fcsr1) & ~mask; +} + /* * Set the FIR feature flags for the FPU emulator. */ @@ -50,11 +79,15 @@ static void cpu_set_nofpu_id(struct cpuinfo_mips *c) c->fpu_id = value; } +/* Determined FPU emulator mask to use for the boot CPU with "nofpu". */ +static unsigned int mips_nofpu_msk31; + static int mips_fpu_disabled; static int __init fpu_disable(char *s) { boot_cpu_data.options &= ~MIPS_CPU_FPU; + boot_cpu_data.fpu_msk31 = mips_nofpu_msk31; cpu_set_nofpu_id(&boot_cpu_data); mips_fpu_disabled = 1; @@ -597,6 +630,7 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu) case PRID_IMP_R2000: c->cputype = CPU_R2000; __cpu_name[cpu] = "R2000"; + c->fpu_msk31 |= FPU_CSR_CONDX | FPU_CSR_FS; c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE | MIPS_CPU_NOFPUEX; if (__cpu_has_fpu()) @@ -616,6 +650,7 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu) c->cputype = CPU_R3000; __cpu_name[cpu] = "R3000"; } + c->fpu_msk31 |= FPU_CSR_CONDX | FPU_CSR_FS; c->options = MIPS_CPU_TLB | MIPS_CPU_3K_CACHE | MIPS_CPU_NOFPUEX; if (__cpu_has_fpu()) @@ -664,6 +699,7 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu) } set_isa(c, MIPS_CPU_ISA_III); + c->fpu_msk31 |= FPU_CSR_CONDX; c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR | MIPS_CPU_WATCH | MIPS_CPU_VCE | MIPS_CPU_LLSC; @@ -671,6 +707,7 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu) break; case PRID_IMP_VR41XX: set_isa(c, MIPS_CPU_ISA_III); + c->fpu_msk31 |= FPU_CSR_CONDX; c->options = R4K_OPTS; c->tlbsize = 32; switch (c->processor_id & 0xf0) { @@ -712,6 +749,7 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu) c->cputype = CPU_R4300; __cpu_name[cpu] = "R4300"; set_isa(c, MIPS_CPU_ISA_III); + c->fpu_msk31 |= FPU_CSR_CONDX; c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR | MIPS_CPU_LLSC; c->tlbsize = 32; @@ -720,6 +758,7 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu) c->cputype = CPU_R4600; __cpu_name[cpu] = "R4600"; set_isa(c, MIPS_CPU_ISA_III); + c->fpu_msk31 |= FPU_CSR_CONDX; c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR | MIPS_CPU_LLSC; c->tlbsize = 48; @@ -735,11 +774,13 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu) c->cputype = CPU_R4650; __cpu_name[cpu] = "R4650"; set_isa(c, MIPS_CPU_ISA_III); + c->fpu_msk31 |= FPU_CSR_CONDX; c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_LLSC; c->tlbsize = 48; break; #endif case PRID_IMP_TX39: + c->fpu_msk31 |= FPU_CSR_CONDX | FPU_CSR_FS; c->options = MIPS_CPU_TLB | MIPS_CPU_TX39_CACHE; if ((c->processor_id & 0xf0) == (PRID_REV_TX3927 & 0xf0)) { @@ -765,6 +806,7 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu) c->cputype = CPU_R4700; __cpu_name[cpu] = "R4700"; set_isa(c, MIPS_CPU_ISA_III); + c->fpu_msk31 |= FPU_CSR_CONDX; c->options = R4K_OPTS | MIPS_CPU_FPU | MIPS_CPU_32FPR | MIPS_CPU_LLSC; c->tlbsize = 48; @@ -773,6 +815,7 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu) c->cputype = CPU_TX49XX; __cpu_name[cpu] = "R49XX"; set_isa(c, MIPS_CPU_ISA_III); + c->fpu_msk31 |= FPU_CSR_CONDX; c->options = R4K_OPTS | MIPS_CPU_LLSC; if (!(c->processor_id & 0x08)) c->options |= MIPS_CPU_FPU | MIPS_CPU_32FPR; @@ -814,6 +857,7 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu) c->cputype = CPU_R6000; __cpu_name[cpu] = "R6000"; set_isa(c, MIPS_CPU_ISA_II); + c->fpu_msk31 |= FPU_CSR_CONDX | FPU_CSR_FS; c->options = MIPS_CPU_TLB | MIPS_CPU_FPU | MIPS_CPU_LLSC; c->tlbsize = 32; @@ -822,6 +866,7 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu) c->cputype = CPU_R6000A; __cpu_name[cpu] = "R6000A"; set_isa(c, MIPS_CPU_ISA_II); + c->fpu_msk31 |= FPU_CSR_CONDX | FPU_CSR_FS; c->options = MIPS_CPU_TLB | MIPS_CPU_FPU | MIPS_CPU_LLSC; c->tlbsize = 32; @@ -893,12 +938,14 @@ static inline void cpu_probe_legacy(struct cpuinfo_mips *c, unsigned int cpu) __cpu_name[cpu] = "ICT Loongson-2"; set_elf_platform(cpu, "loongson2e"); set_isa(c, MIPS_CPU_ISA_III); + c->fpu_msk31 |= FPU_CSR_CONDX; break; case PRID_REV_LOONGSON2F: c->cputype = CPU_LOONGSON2; __cpu_name[cpu] = "ICT Loongson-2"; set_elf_platform(cpu, "loongson2f"); set_isa(c, MIPS_CPU_ISA_III); + c->fpu_msk31 |= FPU_CSR_CONDX; break; case PRID_REV_LOONGSON3A: c->cputype = CPU_LOONGSON3; @@ -1335,6 +1382,9 @@ void cpu_probe(void) c->cputype = CPU_UNKNOWN; c->writecombine = _CACHE_UNCACHED; + c->fpu_csr31 = FPU_CSR_RN; + c->fpu_msk31 = FPU_CSR_RSVD | FPU_CSR_ABS2008 | FPU_CSR_NAN2008; + c->processor_id = read_c0_prid(); switch (c->processor_id & PRID_COMP_MASK) { case PRID_COMP_LEGACY: @@ -1393,6 +1443,7 @@ void cpu_probe(void) if (c->options & MIPS_CPU_FPU) { c->fpu_id = cpu_get_fpu_id(); + mips_nofpu_msk31 = c->fpu_msk31; if (c->isa_level & (MIPS_CPU_ISA_M32R1 | MIPS_CPU_ISA_M64R1 | MIPS_CPU_ISA_M32R2 | MIPS_CPU_ISA_M64R2 | @@ -1402,6 +1453,8 @@ void cpu_probe(void) if (c->fpu_id & MIPS_FPIR_FREP) c->options |= MIPS_CPU_FRE; } + + cpu_set_fpu_fcsr_mask(c); } else cpu_set_nofpu_id(c); diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c index 510452812594..6d1e3f8005f7 100644 --- a/arch/mips/kernel/ptrace.c +++ b/arch/mips/kernel/ptrace.c @@ -32,6 +32,7 @@ #include #include +#include #include #include #include @@ -137,6 +138,9 @@ int ptrace_setfpregs(struct task_struct *child, __u32 __user *data) { union fpureg *fregs; u64 fpr_val; + u32 fcr31; + u32 value; + u32 mask; int i; if (!access_ok(VERIFY_READ, data, 33 * 8)) @@ -149,8 +153,10 @@ int ptrace_setfpregs(struct task_struct *child, __u32 __user *data) set_fpr64(&fregs[i], 0, fpr_val); } - __get_user(child->thread.fpu.fcr31, data + 64); - child->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X; + __get_user(value, data + 64); + fcr31 = child->thread.fpu.fcr31; + mask = current_cpu_data.fpu_msk31; + child->thread.fpu.fcr31 = (value & ~mask) | (fcr31 & mask); /* FIR may not be written. */ diff --git a/arch/mips/kernel/r2300_switch.S b/arch/mips/kernel/r2300_switch.S index 435ea652f5fa..5087a4b72e6b 100644 --- a/arch/mips/kernel/r2300_switch.S +++ b/arch/mips/kernel/r2300_switch.S @@ -115,11 +115,9 @@ LEAF(_restore_fp) * the property that no matter whether considered as single or as double * precision represents signaling NANS. * - * We initialize fcr31 to rounding to nearest, no exceptions. + * The value to initialize fcr31 to comes in $a0. */ -#define FPU_DEFAULT 0x00000000 - .set push SET_HARDFLOAT @@ -129,8 +127,7 @@ LEAF(_init_fpu) or t0, t1 mtc0 t0, CP0_STATUS - li t1, FPU_DEFAULT - ctc1 t1, fcr31 + ctc1 a0, fcr31 li t0, -1 diff --git a/arch/mips/kernel/r4k_switch.S b/arch/mips/kernel/r4k_switch.S index 3b1a36f13a7d..04cbbde3521b 100644 --- a/arch/mips/kernel/r4k_switch.S +++ b/arch/mips/kernel/r4k_switch.S @@ -165,11 +165,9 @@ LEAF(_init_msa_upper) * the property that no matter whether considered as single or as double * precision represents signaling NANS. * - * We initialize fcr31 to rounding to nearest, no exceptions. + * The value to initialize fcr31 to comes in $a0. */ -#define FPU_DEFAULT 0x00000000 - .set push SET_HARDFLOAT @@ -180,8 +178,7 @@ LEAF(_init_fpu) mtc0 t0, CP0_STATUS enable_fpu_hazard - li t1, FPU_DEFAULT - ctc1 t1, fcr31 + ctc1 a0, fcr31 li t1, -1 # SNaN diff --git a/arch/mips/loongson/loongson-3/cop2-ex.c b/arch/mips/loongson/loongson-3/cop2-ex.c index b03e37d2071a..ea13764d0a03 100644 --- a/arch/mips/loongson/loongson-3/cop2-ex.c +++ b/arch/mips/loongson/loongson-3/cop2-ex.c @@ -43,7 +43,7 @@ static int loongson_cu2_call(struct notifier_block *nfb, unsigned long action, if (!fpu_owned) { set_thread_flag(TIF_USEDFPU); if (!used_math()) { - _init_fpu(); + _init_fpu(current->thread.fpu.fcr31); set_used_math(); } else _restore_fp(current); diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c index 3a90170a6277..d31c537ace1d 100644 --- a/arch/mips/math-emu/cp1emu.c +++ b/arch/mips/math-emu/cp1emu.c @@ -908,6 +908,7 @@ static inline void cop1_ctc(struct pt_regs *xcp, struct mips_fpu_struct *ctx, { u32 fcr31 = ctx->fcr31; u32 value; + u32 mask; if (MIPSInst_RT(ir) == 0) value = 0; @@ -919,9 +920,9 @@ static inline void cop1_ctc(struct pt_regs *xcp, struct mips_fpu_struct *ctx, pr_debug("%p gpr[%d]->csr=%08x\n", (void *)xcp->cp0_epc, MIPSInst_RT(ir), value); - /* Don't write unsupported bits. */ - fcr31 = value & - ~(FPU_CSR_RSVD | FPU_CSR_ABS2008 | FPU_CSR_NAN2008); + /* Preserve read-only bits. */ + mask = current_cpu_data.fpu_msk31; + fcr31 = (value & ~mask) | (fcr31 & mask); break; case FPCREG_FENR: