1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ 2 #ifndef _UAPI__ASM_ALPHA_FPU_H 3 #define _UAPI__ASM_ALPHA_FPU_H 4 5 6 /* 7 * Alpha floating-point control register defines: 8 */ 9 #define FPCR_DNOD (1UL<<47) /* denorm INV trap disable */ 10 #define FPCR_DNZ (1UL<<48) /* denorms to zero */ 11 #define FPCR_INVD (1UL<<49) /* invalid op disable (opt.) */ 12 #define FPCR_DZED (1UL<<50) /* division by zero disable (opt.) */ 13 #define FPCR_OVFD (1UL<<51) /* overflow disable (optional) */ 14 #define FPCR_INV (1UL<<52) /* invalid operation */ 15 #define FPCR_DZE (1UL<<53) /* division by zero */ 16 #define FPCR_OVF (1UL<<54) /* overflow */ 17 #define FPCR_UNF (1UL<<55) /* underflow */ 18 #define FPCR_INE (1UL<<56) /* inexact */ 19 #define FPCR_IOV (1UL<<57) /* integer overflow */ 20 #define FPCR_UNDZ (1UL<<60) /* underflow to zero (opt.) */ 21 #define FPCR_UNFD (1UL<<61) /* underflow disable (opt.) */ 22 #define FPCR_INED (1UL<<62) /* inexact disable (opt.) */ 23 #define FPCR_SUM (1UL<<63) /* summary bit */ 24 25 #define FPCR_DYN_SHIFT 58 /* first dynamic rounding mode bit */ 26 #define FPCR_DYN_CHOPPED (0x0UL << FPCR_DYN_SHIFT) /* towards 0 */ 27 #define FPCR_DYN_MINUS (0x1UL << FPCR_DYN_SHIFT) /* towards -INF */ 28 #define FPCR_DYN_NORMAL (0x2UL << FPCR_DYN_SHIFT) /* towards nearest */ 29 #define FPCR_DYN_PLUS (0x3UL << FPCR_DYN_SHIFT) /* towards +INF */ 30 #define FPCR_DYN_MASK (0x3UL << FPCR_DYN_SHIFT) 31 32 #define FPCR_MASK 0xffff800000000000L 33 34 /* 35 * IEEE trap enables are implemented in software. These per-thread 36 * bits are stored in the "ieee_state" field of "struct thread_info". 37 * Thus, the bits are defined so as not to conflict with the 38 * floating-point enable bit (which is architected). On top of that, 39 * we want to make these bits compatible with OSF/1 so 40 * ieee_set_fp_control() etc. can be implemented easily and 41 * compatibly. The corresponding definitions are in 42 * /usr/include/machine/fpu.h under OSF/1. 43 */ 44 #define IEEE_TRAP_ENABLE_INV (1UL<<1) /* invalid op */ 45 #define IEEE_TRAP_ENABLE_DZE (1UL<<2) /* division by zero */ 46 #define IEEE_TRAP_ENABLE_OVF (1UL<<3) /* overflow */ 47 #define IEEE_TRAP_ENABLE_UNF (1UL<<4) /* underflow */ 48 #define IEEE_TRAP_ENABLE_INE (1UL<<5) /* inexact */ 49 #define IEEE_TRAP_ENABLE_DNO (1UL<<6) /* denorm */ 50 #define IEEE_TRAP_ENABLE_MASK (IEEE_TRAP_ENABLE_INV | IEEE_TRAP_ENABLE_DZE |\ 51 IEEE_TRAP_ENABLE_OVF | IEEE_TRAP_ENABLE_UNF |\ 52 IEEE_TRAP_ENABLE_INE | IEEE_TRAP_ENABLE_DNO) 53 54 /* Denorm and Underflow flushing */ 55 #define IEEE_MAP_DMZ (1UL<<12) /* Map denorm inputs to zero */ 56 #define IEEE_MAP_UMZ (1UL<<13) /* Map underflowed outputs to zero */ 57 58 #define IEEE_MAP_MASK (IEEE_MAP_DMZ | IEEE_MAP_UMZ) 59 60 /* status bits coming from fpcr: */ 61 #define IEEE_STATUS_INV (1UL<<17) 62 #define IEEE_STATUS_DZE (1UL<<18) 63 #define IEEE_STATUS_OVF (1UL<<19) 64 #define IEEE_STATUS_UNF (1UL<<20) 65 #define IEEE_STATUS_INE (1UL<<21) 66 #define IEEE_STATUS_DNO (1UL<<22) 67 68 #define IEEE_STATUS_MASK (IEEE_STATUS_INV | IEEE_STATUS_DZE | \ 69 IEEE_STATUS_OVF | IEEE_STATUS_UNF | \ 70 IEEE_STATUS_INE | IEEE_STATUS_DNO) 71 72 #define IEEE_SW_MASK (IEEE_TRAP_ENABLE_MASK | \ 73 IEEE_STATUS_MASK | IEEE_MAP_MASK) 74 75 #define IEEE_CURRENT_RM_SHIFT 32 76 #define IEEE_CURRENT_RM_MASK (3UL<<IEEE_CURRENT_RM_SHIFT) 77 78 #define IEEE_STATUS_TO_EXCSUM_SHIFT 16 79 80 #define IEEE_INHERIT (1UL<<63) /* inherit on thread create? */ 81 82 /* 83 * Convert the software IEEE trap enable and status bits into the 84 * hardware fpcr format. 85 * 86 * Digital Unix engineers receive my thanks for not defining the 87 * software bits identical to the hardware bits. The chip designers 88 * receive my thanks for making all the not-implemented fpcr bits 89 * RAZ forcing us to use system calls to read/write this value. 90 */ 91 92 static inline unsigned long 93 ieee_swcr_to_fpcr(unsigned long sw) 94 { 95 unsigned long fp; 96 fp = (sw & IEEE_STATUS_MASK) << 35; 97 fp |= (sw & IEEE_MAP_DMZ) << 36; 98 fp |= (sw & IEEE_STATUS_MASK ? FPCR_SUM : 0); 99 fp |= (~sw & (IEEE_TRAP_ENABLE_INV 100 | IEEE_TRAP_ENABLE_DZE 101 | IEEE_TRAP_ENABLE_OVF)) << 48; 102 fp |= (~sw & (IEEE_TRAP_ENABLE_UNF | IEEE_TRAP_ENABLE_INE)) << 57; 103 fp |= (sw & IEEE_MAP_UMZ ? FPCR_UNDZ | FPCR_UNFD : 0); 104 fp |= (~sw & IEEE_TRAP_ENABLE_DNO) << 41; 105 return fp; 106 } 107 108 static inline unsigned long 109 ieee_fpcr_to_swcr(unsigned long fp) 110 { 111 unsigned long sw; 112 sw = (fp >> 35) & IEEE_STATUS_MASK; 113 sw |= (fp >> 36) & IEEE_MAP_DMZ; 114 sw |= (~fp >> 48) & (IEEE_TRAP_ENABLE_INV 115 | IEEE_TRAP_ENABLE_DZE 116 | IEEE_TRAP_ENABLE_OVF); 117 sw |= (~fp >> 57) & (IEEE_TRAP_ENABLE_UNF | IEEE_TRAP_ENABLE_INE); 118 sw |= (fp >> 47) & IEEE_MAP_UMZ; 119 sw |= (~fp >> 41) & IEEE_TRAP_ENABLE_DNO; 120 return sw; 121 } 122 123 124 #endif /* _UAPI__ASM_ALPHA_FPU_H */ 125