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Diffstat (limited to 'arch/alpha/include/asm/fpu.h')
| -rw-r--r-- | arch/alpha/include/asm/fpu.h | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/arch/alpha/include/asm/fpu.h b/arch/alpha/include/asm/fpu.h new file mode 100644 index 000000000000..ecb17a72acc3 --- /dev/null +++ b/arch/alpha/include/asm/fpu.h @@ -0,0 +1,193 @@ +#ifndef __ASM_ALPHA_FPU_H +#define __ASM_ALPHA_FPU_H + +/* + * Alpha floating-point control register defines: + */ +#define FPCR_DNOD (1UL<<47) /* denorm INV trap disable */ +#define FPCR_DNZ (1UL<<48) /* denorms to zero */ +#define FPCR_INVD (1UL<<49) /* invalid op disable (opt.) */ +#define FPCR_DZED (1UL<<50) /* division by zero disable (opt.) */ +#define FPCR_OVFD (1UL<<51) /* overflow disable (optional) */ +#define FPCR_INV (1UL<<52) /* invalid operation */ +#define FPCR_DZE (1UL<<53) /* division by zero */ +#define FPCR_OVF (1UL<<54) /* overflow */ +#define FPCR_UNF (1UL<<55) /* underflow */ +#define FPCR_INE (1UL<<56) /* inexact */ +#define FPCR_IOV (1UL<<57) /* integer overflow */ +#define FPCR_UNDZ (1UL<<60) /* underflow to zero (opt.) */ +#define FPCR_UNFD (1UL<<61) /* underflow disable (opt.) */ +#define FPCR_INED (1UL<<62) /* inexact disable (opt.) */ +#define FPCR_SUM (1UL<<63) /* summary bit */ + +#define FPCR_DYN_SHIFT 58 /* first dynamic rounding mode bit */ +#define FPCR_DYN_CHOPPED (0x0UL << FPCR_DYN_SHIFT) /* towards 0 */ +#define FPCR_DYN_MINUS (0x1UL << FPCR_DYN_SHIFT) /* towards -INF */ +#define FPCR_DYN_NORMAL (0x2UL << FPCR_DYN_SHIFT) /* towards nearest */ +#define FPCR_DYN_PLUS (0x3UL << FPCR_DYN_SHIFT) /* towards +INF */ +#define FPCR_DYN_MASK (0x3UL << FPCR_DYN_SHIFT) + +#define FPCR_MASK 0xffff800000000000L + +/* + * IEEE trap enables are implemented in software. These per-thread + * bits are stored in the "ieee_state" field of "struct thread_info". + * Thus, the bits are defined so as not to conflict with the + * floating-point enable bit (which is architected). On top of that, + * we want to make these bits compatible with OSF/1 so + * ieee_set_fp_control() etc. can be implemented easily and + * compatibly. The corresponding definitions are in + * /usr/include/machine/fpu.h under OSF/1. + */ +#define IEEE_TRAP_ENABLE_INV (1UL<<1) /* invalid op */ +#define IEEE_TRAP_ENABLE_DZE (1UL<<2) /* division by zero */ +#define IEEE_TRAP_ENABLE_OVF (1UL<<3) /* overflow */ +#define IEEE_TRAP_ENABLE_UNF (1UL<<4) /* underflow */ +#define IEEE_TRAP_ENABLE_INE (1UL<<5) /* inexact */ +#define IEEE_TRAP_ENABLE_DNO (1UL<<6) /* denorm */ +#define IEEE_TRAP_ENABLE_MASK (IEEE_TRAP_ENABLE_INV | IEEE_TRAP_ENABLE_DZE |\ + IEEE_TRAP_ENABLE_OVF | IEEE_TRAP_ENABLE_UNF |\ + IEEE_TRAP_ENABLE_INE | IEEE_TRAP_ENABLE_DNO) + +/* Denorm and Underflow flushing */ +#define IEEE_MAP_DMZ (1UL<<12) /* Map denorm inputs to zero */ +#define IEEE_MAP_UMZ (1UL<<13) /* Map underflowed outputs to zero */ + +#define IEEE_MAP_MASK (IEEE_MAP_DMZ | IEEE_MAP_UMZ) + +/* status bits coming from fpcr: */ +#define IEEE_STATUS_INV (1UL<<17) +#define IEEE_STATUS_DZE (1UL<<18) +#define IEEE_STATUS_OVF (1UL<<19) +#define IEEE_STATUS_UNF (1UL<<20) +#define IEEE_STATUS_INE (1UL<<21) +#define IEEE_STATUS_DNO (1UL<<22) + +#define IEEE_STATUS_MASK (IEEE_STATUS_INV | IEEE_STATUS_DZE | \ + IEEE_STATUS_OVF | IEEE_STATUS_UNF | \ + IEEE_STATUS_INE | IEEE_STATUS_DNO) + +#define IEEE_SW_MASK (IEEE_TRAP_ENABLE_MASK | \ + IEEE_STATUS_MASK | IEEE_MAP_MASK) + +#define IEEE_CURRENT_RM_SHIFT 32 +#define IEEE_CURRENT_RM_MASK (3UL<<IEEE_CURRENT_RM_SHIFT) + +#define IEEE_STATUS_TO_EXCSUM_SHIFT 16 + +#define IEEE_INHERIT (1UL<<63) /* inherit on thread create? */ + +/* + * Convert the software IEEE trap enable and status bits into the + * hardware fpcr format. + * + * Digital Unix engineers receive my thanks for not defining the + * software bits identical to the hardware bits. The chip designers + * receive my thanks for making all the not-implemented fpcr bits + * RAZ forcing us to use system calls to read/write this value. + */ + +static inline unsigned long +ieee_swcr_to_fpcr(unsigned long sw) +{ + unsigned long fp; + fp = (sw & IEEE_STATUS_MASK) << 35; + fp |= (sw & IEEE_MAP_DMZ) << 36; + fp |= (sw & IEEE_STATUS_MASK ? FPCR_SUM : 0); + fp |= (~sw & (IEEE_TRAP_ENABLE_INV + | IEEE_TRAP_ENABLE_DZE + | IEEE_TRAP_ENABLE_OVF)) << 48; + fp |= (~sw & (IEEE_TRAP_ENABLE_UNF | IEEE_TRAP_ENABLE_INE)) << 57; + fp |= (sw & IEEE_MAP_UMZ ? FPCR_UNDZ | FPCR_UNFD : 0); + fp |= (~sw & IEEE_TRAP_ENABLE_DNO) << 41; + return fp; +} + +static inline unsigned long +ieee_fpcr_to_swcr(unsigned long fp) +{ + unsigned long sw; + sw = (fp >> 35) & IEEE_STATUS_MASK; + sw |= (fp >> 36) & IEEE_MAP_DMZ; + sw |= (~fp >> 48) & (IEEE_TRAP_ENABLE_INV + | IEEE_TRAP_ENABLE_DZE + | IEEE_TRAP_ENABLE_OVF); + sw |= (~fp >> 57) & (IEEE_TRAP_ENABLE_UNF | IEEE_TRAP_ENABLE_INE); + sw |= (fp >> 47) & IEEE_MAP_UMZ; + sw |= (~fp >> 41) & IEEE_TRAP_ENABLE_DNO; + return sw; +} + +#ifdef __KERNEL__ + +/* The following two functions don't need trapb/excb instructions + around the mf_fpcr/mt_fpcr instructions because (a) the kernel + never generates arithmetic faults and (b) call_pal instructions + are implied trap barriers. */ + +static inline unsigned long +rdfpcr(void) +{ + unsigned long tmp, ret; + +#if defined(CONFIG_ALPHA_EV6) || defined(CONFIG_ALPHA_EV67) + __asm__ __volatile__ ( + "ftoit $f0,%0\n\t" + "mf_fpcr $f0\n\t" + "ftoit $f0,%1\n\t" + "itoft %0,$f0" + : "=r"(tmp), "=r"(ret)); +#else + __asm__ __volatile__ ( + "stt $f0,%0\n\t" + "mf_fpcr $f0\n\t" + "stt $f0,%1\n\t" + "ldt $f0,%0" + : "=m"(tmp), "=m"(ret)); +#endif + + return ret; +} + +static inline void +wrfpcr(unsigned long val) +{ + unsigned long tmp; + +#if defined(CONFIG_ALPHA_EV6) || defined(CONFIG_ALPHA_EV67) + __asm__ __volatile__ ( + "ftoit $f0,%0\n\t" + "itoft %1,$f0\n\t" + "mt_fpcr $f0\n\t" + "itoft %0,$f0" + : "=&r"(tmp) : "r"(val)); +#else + __asm__ __volatile__ ( + "stt $f0,%0\n\t" + "ldt $f0,%1\n\t" + "mt_fpcr $f0\n\t" + "ldt $f0,%0" + : "=m"(tmp) : "m"(val)); +#endif +} + +static inline unsigned long +swcr_update_status(unsigned long swcr, unsigned long fpcr) +{ + /* EV6 implements most of the bits in hardware. Collect + the acrued exception bits from the real fpcr. */ + if (implver() == IMPLVER_EV6) { + swcr &= ~IEEE_STATUS_MASK; + swcr |= (fpcr >> 35) & IEEE_STATUS_MASK; + } + return swcr; +} + +extern unsigned long alpha_read_fp_reg (unsigned long reg); +extern void alpha_write_fp_reg (unsigned long reg, unsigned long val); +extern unsigned long alpha_read_fp_reg_s (unsigned long reg); +extern void alpha_write_fp_reg_s (unsigned long reg, unsigned long val); + +#endif /* __KERNEL__ */ + +#endif /* __ASM_ALPHA_FPU_H */ |