ref: 1d4a36c69913f117516b0f062745fe95d35545ba
dir: /sys/src/9/teg2/softfpu.c/
#include "u.h" #include "../port/lib.h" #include "mem.h" #include "dat.h" #include "fns.h" int fpudevprocio(Proc* proc, void* a, long n, uintptr offset, int write) { /* * Called from procdevtab.read and procdevtab.write * allow user process access to the FPU registers. * This is the only FPU routine which is called directly * from the port code; it would be nice to have dynamic * creation of entries in the device file trees... */ USED(proc, a, n, offset, write); return 0; } void fpunotify(Ureg*) { /* * Called when a note is about to be delivered to a * user process, usually at the end of a system call. * Note handlers are not allowed to use the FPU so * the state is marked (after saving if necessary) and * checked in the Device Not Available handler. */ } void fpunoted(void) { /* * Called from sysnoted() via the machine-dependent * noted() routine. * Clear the flag set above in fpunotify(). */ } void fpuprocrestore(Proc*) { /* * The process has been rescheduled and is about to run. * Nothing to do here right now. If the process tries to use * the FPU again it will cause a Device Not Available * exception and the state will then be restored. */ } void fpuprocfork(Proc*) { /* * The current process has been forked, save and copy neccesary * state to child. Nothing to do here, child proc starts with FPinit. */ } void fpuprocsave(Proc*) { /* * Called from sched() and sleep() via the machine-dependent * procsave() routine. * About to go in to the scheduler. * If the process wasn't using the FPU * there's nothing to do. */ } void fpusysprocsetup(Proc*) { /* * Disable the FPU. * Called from sysexec() via sysprocsetup() to * set the FPU for the new process. */ } void fpuinit(void) { } int fpuemu(Ureg* ureg) { int nfp; if(waserror()){ splhi(); postnote(up, 1, up->errstr, NDebug); return 1; } spllo(); nfp = fpiarm(ureg); splhi(); poperror(); return nfp; } void fpon(void) { } void fpoff(void) { }