projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 33822afd BJ |
1 | /* |
| 2 | * 387 and 287 Numeric Coprocessor Extension (NPX) Driver. | |
| 3 | * @(#)npx.c 1.1 (Berkeley) %G% | |
| 4 | */ | |
| 5 | ||
| 6 | int npxprobe(), npxattach(), npxintr(); | |
| 7 | struct driver npxdriver = { | |
| 8 | npxprobe, npxattach, "npx", | |
| 9 | }; | |
| 10 | ||
| 11 | struct proc *npxproc; /* process who owns device, otherwise zero */ | |
| 12 | struct user *npxutl; /* owners user structure */ | |
| 13 | struct pte *Npxmap; /* kernel ptes mapping owner's user structure */ | |
| 14 | ||
| 15 | /* | |
| 16 | * Probe routine - look device, otherwise set emulator bit | |
| 17 | */ | |
| 18 | npxprobe(dvp) | |
| 19 | struct device *dvp; | |
| 20 | { | |
| 21 | register status; | |
| 22 | ||
| 23 | #ifdef lint | |
| 24 | npxintr(); | |
| 25 | #endif | |
| 26 | /* insure EM bit off */ | |
| 27 | asm(" fninit"); /* put device in known state */ | |
| 28 | ||
| 29 | /* check for a proper status of zero */ | |
| 30 | status = 0xa5a5; | |
| 31 | asm(" movw %1,%%ax ; fnstsw %%ax ; movw %%ax, %0" | |
| 32 | : "=g" (status) : "g" (status) : "ax"); | |
| 33 | ||
| 34 | if (status == 0) { | |
| 35 | register control; | |
| 36 | ||
| 37 | /* good, now check for a proper control word */ | |
| 38 | control = 0xa5a5; | |
| 39 | asm(" movw %1,%%ax ; fnstcw %%ax ; movw %%ax, %0" | |
| 40 | : "=g" (control) : "g" (control) : "ax"); | |
| 41 | ||
| 42 | if (control&0x103f == 0x3f) { | |
| 43 | /* then we have a numeric coprocessor */ | |
| 44 | /* XXX should force an exception here to generate an intr */ | |
| 45 | return (1); | |
| 46 | } | |
| 47 | } | |
| 48 | ||
| 49 | /* insure EM bit on */ | |
| 50 | return (0); | |
| 51 | } | |
| 52 | ||
| 53 | /* | |
| 54 | * Attach routine - announce which it is, and wire into system | |
| 55 | */ | |
| 56 | npxattach(dvp) | |
| 57 | struct device *dvp; | |
| 58 | { | |
| 59 | int unit = dvp->unit; | |
| 60 | ||
| 61 | npxinit(); | |
| 62 | /* check for ET bit to decide 387/287 */ | |
| 63 | INTREN(IRQ13); | |
| 64 | /*outb(0xb1,0); /* reset processor */ | |
| 65 | } | |
| 66 | ||
| 67 | /* | |
| 68 | * Initialize floating point unit, usually after an error | |
| 69 | */ | |
| 70 | npxinit() { | |
| 71 | register control; | |
| 72 | ||
| 73 | asm (" fninit"); | |
| 74 | control = XXX; | |
| 75 | asm(" movw %0,%%ax ; fldcw %%ax " | |
| 76 | : "g" (control) : "ax"); | |
| 77 | ||
| 78 | } | |
| 79 | ||
| 80 | /* | |
| 81 | * Load floating point context and record ownership to suite | |
| 82 | */ | |
| 83 | npxload() { | |
| 84 | ||
| 85 | if (npxproc) panic ("npxload"); | |
| 86 | npxproc = u.u_procp; | |
| 87 | uaccess(npxproc, Npxmap, &npxutl); | |
| 88 | asm(" frstor %0 " : "g" (u.u_pcb.pcb_savefpu) ); | |
| 89 | } | |
| 90 | ||
| 91 | /* | |
| 92 | * Unload floating point context and relinquish ownership | |
| 93 | */ | |
| 94 | npxunload() { | |
| 95 | ||
| 96 | if (npxproc == 0) panic ("npxunload"); | |
| 97 | asm(" fsave %0 " : "g" (npxutl.u_pcb.pcb_savefpu) ); | |
| 98 | npxproc = 0 ; | |
| 99 | } | |
| 100 | ||
| 101 | /* | |
| 102 | * Record information needed in processing an exception and clear status word | |
| 103 | */ | |
| 104 | npxexcept() { | |
| 105 | ||
| 106 | /* save state in appropriate user structure */ | |
| 107 | if (npxproc == 0) panic ("npxexcept"); | |
| 108 | asm (" fsave %0 " : "g" (npxutl.u_pcb.pcb_savefpu) ); | |
| 109 | ||
| 110 | /* | |
| 111 | * encode the appropriate u_code for detailed information | |
| 112 | * on this exception | |
| 113 | */ | |
| 114 | ||
| 115 | /* signal appropriate process */ | |
| 116 | psignal (npxproc, SIGFPE); | |
| 117 | ||
| 118 | /* clear the exception so we can catch others like it */ | |
| 119 | asm (" fnclex"); | |
| 120 | } | |
| 121 | ||
| 122 | /* | |
| 123 | * Catch AT/386 interrupt used to signal exception, and simulate trap() | |
| 124 | */ | |
| 125 | npxintr() { | |
| 126 | outb(0xf0,0); | |
| 127 | pg("npxintr"); | |
| 128 | } | |
| 129 | ||
| 130 | /* | |
| 131 | * Implement device not available (DNA) exception | |
| 132 | */ | |
| 133 | npxdna() { | |
| 134 | } |