ref: c1d40df49550393f3afe53fb6e6d500dfa8eb7a8
dir: /sys/src/9/bcm64/fpu.c/
#include "u.h" #include "../port/lib.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "ureg.h" #include "sysreg.h" /* libc */ extern ulong getfcr(void); extern void setfcr(ulong fcr); extern ulong getfsr(void); extern void setfsr(ulong fsr); static FPsave fpsave0; static void fpsave(FPsave *p) { p->control = getfcr(); p->status = getfsr(); fpsaveregs(p->regs); fpoff(); } static void fprestore(FPsave *p) { fpon(); setfcr(p->control); setfsr(p->status); fploadregs(p->regs); } static void fpinit(void) { fprestore(&fpsave0); } void fpuinit(void) { m->fpstate = FPinit; m->fpsave = nil; fpoff(); } static FPsave* fpalloc(void) { FPsave *save; while((save = mallocalign(sizeof(FPsave), 16, 0, 0)) == nil){ spllo(); resrcwait("no memory for FPsave"); splhi(); } return save; } static void fpfree(FPsave *save) { free(save); } /* * Protect or save FPU state and setup new state * (lazily in the case of user process) for the kernel. * All syscalls, traps and interrupts (except mathtrap()!) * are handled between fpukenter() and fpukexit(), * so they can use floating point and vector instructions. */ FPsave* fpukenter(Ureg*) { if(up == nil){ switch(m->fpstate){ case FPactive: fpsave(m->fpsave); /* wet floor */ case FPinactive: m->fpstate = FPinit; return m->fpsave; } return nil; } switch(up->fpstate){ case FPactive: up->fpstate = FPprotected; fpoff(); /* wet floor */ case FPprotected: return nil; } switch(up->kfpstate){ case FPactive: fpsave(up->kfpsave); /* wet floor */ case FPinactive: up->kfpstate = FPinit; return up->kfpsave; } return nil; } void fpukexit(Ureg *ureg, FPsave *save) { if(up == nil){ switch(m->fpstate){ case FPactive: fpoff(); /* wet floor */ case FPinactive: fpfree(m->fpsave); m->fpstate = FPinit; } m->fpsave = save; if(save != nil) m->fpstate = FPinactive; return; } if(up->fpstate == FPprotected){ if(userureg(ureg)){ up->fpstate = FPactive; fpon(); } return; } switch(up->kfpstate){ case FPactive: fpoff(); /* wet floor */ case FPinactive: fpfree(up->kfpsave); up->kfpstate = FPinit; } up->kfpsave = save; if(save != nil) up->kfpstate = FPinactive; } void fpuprocsetup(Proc *p) { p->fpstate = FPinit; } void fpuprocfork(Proc *p) { int s; s = splhi(); switch(up->fpstate & ~FPillegal){ case FPprotected: fpon(); /* wet floor */ case FPactive: fpsave(up->fpsave); up->fpstate = FPinactive; /* wet floor */ case FPinactive: if(p->fpsave == nil) p->fpsave = fpalloc(); memmove(p->fpsave, up->fpsave, sizeof(FPsave)); p->fpstate = FPinactive; } splx(s); } void fpuprocsave(Proc *p) { if(p->state == Moribund){ if(p->fpstate == FPactive || p->kfpstate == FPactive) fpoff(); fpfree(p->fpsave); fpfree(p->kfpsave); p->fpsave = p->kfpsave = nil; p->fpstate = p->kfpstate = FPinit; return; } if(p->kfpstate == FPactive){ fpsave(p->kfpsave); p->kfpstate = FPinactive; return; } if(p->fpstate == FPprotected) fpon(); else if(p->fpstate != FPactive) return; fpsave(p->fpsave); p->fpstate = FPinactive; } void fpuprocrestore(Proc*) { /* * when the scheduler switches, * we can discard its fp state. */ switch(m->fpstate){ case FPactive: fpoff(); /* wet floor */ case FPinactive: fpfree(m->fpsave); m->fpsave = nil; m->fpstate = FPinit; } } void mathtrap(Ureg *ureg) { if(!userureg(ureg)){ if(up == nil){ switch(m->fpstate){ case FPinit: m->fpsave = fpalloc(); m->fpstate = FPactive; fpinit(); break; case FPinactive: fprestore(m->fpsave); m->fpstate = FPactive; break; default: panic("floating point error in irq"); } return; } if(up->fpstate == FPprotected){ fpon(); fpsave(up->fpsave); up->fpstate = FPinactive; } switch(up->kfpstate){ case FPinit: up->kfpsave = fpalloc(); up->kfpstate = FPactive; fpinit(); break; case FPinactive: fprestore(up->kfpsave); up->kfpstate = FPactive; break; default: panic("floating point error in trap"); } return; } if(up->fpstate & FPillegal){ postnote(up, 1, "sys: floating point in note handler", NDebug); return; } switch(up->fpstate){ case FPinit: if(up->fpsave == nil) up->fpsave = fpalloc(); up->fpstate = FPactive; fpinit(); break; case FPinactive: fprestore(up->fpsave); up->fpstate = FPactive; break; case FPprotected: up->fpstate = FPactive; fpon(); break; case FPactive: postnote(up, 1, "sys: floating point error", NDebug); break; } }