diff --git a/arch/mips/include/asm/elf.h b/arch/mips/include/asm/elf.h index 1d38fe0edd2d..9343529db7bc 100644 --- a/arch/mips/include/asm/elf.h +++ b/arch/mips/include/asm/elf.h @@ -269,6 +269,8 @@ do { \ else \ set_thread_flag(TIF_32BIT_FPREGS); \ \ + clear_thread_flag(TIF_HYBRID_FPREGS); \ + \ if (personality(current->personality) != PER_LINUX) \ set_personality(PER_LINUX); \ \ @@ -325,6 +327,7 @@ do { \ \ clear_thread_flag(TIF_32BIT_REGS); \ clear_thread_flag(TIF_32BIT_FPREGS); \ + clear_thread_flag(TIF_HYBRID_FPREGS); \ clear_thread_flag(TIF_32BIT_ADDR); \ \ if ((ex).e_ident[EI_CLASS] == ELFCLASS32) \ diff --git a/arch/mips/include/asm/fpu.h b/arch/mips/include/asm/fpu.h index dd562414cd5e..994d21939676 100644 --- a/arch/mips/include/asm/fpu.h +++ b/arch/mips/include/asm/fpu.h @@ -36,14 +36,16 @@ extern void _restore_fp(struct task_struct *); /* * This enum specifies a mode in which we want the FPU to operate, for cores - * which implement the Status.FR bit. Note that FPU_32BIT & FPU_64BIT - * purposefully have the values 0 & 1 respectively, so that an integer value - * of Status.FR can be trivially casted to the corresponding enum fpu_mode. + * which implement the Status.FR bit. Note that the bottom bit of the value + * purposefully matches the desired value of the Status.FR bit. */ enum fpu_mode { FPU_32BIT = 0, /* FR = 0 */ - FPU_64BIT, /* FR = 1 */ + FPU_64BIT, /* FR = 1, FRE = 0 */ FPU_AS_IS, + FPU_HYBRID, /* FR = 1, FRE = 1 */ + +#define FPU_FR_MASK 0x1 }; static inline int __enable_fpu(enum fpu_mode mode) @@ -57,6 +59,14 @@ static inline int __enable_fpu(enum fpu_mode mode) enable_fpu_hazard(); return 0; + case FPU_HYBRID: + if (!cpu_has_fre) + return SIGFPE; + + /* set FRE */ + write_c0_config5(read_c0_config5() | MIPS_CONF5_FRE); + goto fr_common; + case FPU_64BIT: #if !(defined(CONFIG_CPU_MIPS32_R2) || defined(CONFIG_64BIT)) /* we only have a 32-bit FPU */ @@ -64,8 +74,11 @@ static inline int __enable_fpu(enum fpu_mode mode) #endif /* fall through */ case FPU_32BIT: + /* clear FRE */ + write_c0_config5(read_c0_config5() & ~MIPS_CONF5_FRE); +fr_common: /* set CU1 & change FR appropriately */ - fr = (int)mode; + fr = (int)mode & FPU_FR_MASK; change_c0_status(ST0_CU1 | ST0_FR, ST0_CU1 | (fr ? ST0_FR : 0)); enable_fpu_hazard(); @@ -102,13 +115,17 @@ static inline int __own_fpu(void) enum fpu_mode mode; int ret; - mode = !test_thread_flag(TIF_32BIT_FPREGS); + if (test_thread_flag(TIF_HYBRID_FPREGS)) + mode = FPU_HYBRID; + else + mode = !test_thread_flag(TIF_32BIT_FPREGS); + ret = __enable_fpu(mode); if (ret) return ret; KSTK_STATUS(current) |= ST0_CU1; - if (mode == FPU_64BIT) + if (mode == FPU_64BIT || mode == FPU_HYBRID) KSTK_STATUS(current) |= ST0_FR; else /* mode == FPU_32BIT */ KSTK_STATUS(current) &= ~ST0_FR; @@ -166,8 +183,24 @@ static inline int init_fpu(void) if (cpu_has_fpu) { ret = __own_fpu(); - if (!ret) + if (!ret) { + unsigned int config5 = read_c0_config5(); + + /* + * Ensure FRE is clear whilst running _init_fpu, since + * single precision FP instructions are used. If FRE + * was set then we'll just end up initialising all 32 + * 64b registers. + */ + write_c0_config5(config5 & ~MIPS_CONF5_FRE); + enable_fpu_hazard(); + _init_fpu(); + + /* Restore FRE */ + write_c0_config5(config5); + enable_fpu_hazard(); + } } else fpu_emulator_init_fpu(); diff --git a/arch/mips/include/asm/thread_info.h b/arch/mips/include/asm/thread_info.h index 7de865805deb..99eea59604e9 100644 --- a/arch/mips/include/asm/thread_info.h +++ b/arch/mips/include/asm/thread_info.h @@ -116,6 +116,7 @@ static inline struct thread_info *current_thread_info(void) #define TIF_LOAD_WATCH 25 /* If set, load watch registers */ #define TIF_SYSCALL_TRACEPOINT 26 /* syscall tracepoint instrumentation */ #define TIF_32BIT_FPREGS 27 /* 32-bit floating point registers */ +#define TIF_HYBRID_FPREGS 28 /* 64b FP registers, odd singles in bits 63:32 of even doubles */ #define TIF_USEDMSA 29 /* MSA has been used this quantum */ #define TIF_MSA_CTX_LIVE 30 /* MSA context must be preserved */ #define TIF_SYSCALL_TRACE 31 /* syscall trace active */ @@ -135,6 +136,7 @@ static inline struct thread_info *current_thread_info(void) #define _TIF_FPUBOUND (1<cp0_epc = old_epc; + regs->regs[31] = old_ra; + + /* Save the FP context to struct thread_struct */ + lose_fpu(1); + + /* Run the emulator */ + sig = fpu_emulator_cop1Handler(regs, ¤t->thread.fpu, 1, + &fault_addr); + + /* If something went wrong, signal */ + process_fpemu_return(sig, fault_addr); + + /* Restore the hardware register state */ + own_fpu(1); + + return 0; +} + /* * XXX Delayed fp exceptions when doing a lazy ctx switch XXX */ @@ -1016,6 +1060,9 @@ asmlinkage void do_ri(struct pt_regs *regs) if (status < 0) status = simulate_sync(regs, opcode); + + if (status < 0) + status = simulate_fp(regs, opcode, old_epc, old31); } if (status < 0) diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c index cac529a405b8..9dfcd7fc1bc3 100644 --- a/arch/mips/math-emu/cp1emu.c +++ b/arch/mips/math-emu/cp1emu.c @@ -643,9 +643,14 @@ static inline int cop1_64bit(struct pt_regs *xcp) return !test_thread_flag(TIF_32BIT_FPREGS); } +static inline bool hybrid_fprs(void) +{ + return test_thread_flag(TIF_HYBRID_FPREGS); +} + #define SIFROMREG(si, x) \ do { \ - if (cop1_64bit(xcp)) \ + if (cop1_64bit(xcp) && !hybrid_fprs()) \ (si) = (int)get_fpr32(&ctx->fpr[x], 0); \ else \ (si) = (int)get_fpr32(&ctx->fpr[(x) & ~1], (x) & 1); \ @@ -653,7 +658,7 @@ do { \ #define SITOREG(si, x) \ do { \ - if (cop1_64bit(xcp)) { \ + if (cop1_64bit(xcp) && !hybrid_fprs()) { \ unsigned i; \ set_fpr32(&ctx->fpr[x], 0, si); \ for (i = 1; i < ARRAY_SIZE(ctx->fpr[x].val32); i++) \