Add kernel support needed for the KSE-aware libpthread:
- Maintain fpu state across signals. - Save and restore FPU state properly in ucontext_t's. Reviewed by: bde, deischen, julian Approved by: -arch
This commit is contained in:
Jonathan Mini
parent
9ba1547929
commit
30abe507c0
@ -74,6 +74,7 @@
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#include <machine/resource.h>
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#include <machine/specialreg.h>
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#include <machine/segments.h>
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#include <machine/ucontext.h>
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#ifndef SMP
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#include <i386/isa/icu.h>
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@ -151,17 +152,11 @@ void stop_emulating(void);
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(cpu_fxsr ? \
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(thread)->td_pcb->pcb_save.sv_xmm.sv_env.en_sw : \
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(thread)->td_pcb->pcb_save.sv_87.sv_env.en_sw)
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#define GET_FPU_EXSW_PTR(pcb) \
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(cpu_fxsr ? \
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&(pcb)->pcb_save.sv_xmm.sv_ex_sw : \
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&(pcb)->pcb_save.sv_87.sv_ex_sw)
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#else /* CPU_ENABLE_SSE */
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#define GET_FPU_CW(thread) \
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(thread->td_pcb->pcb_save.sv_87.sv_env.en_cw)
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#define GET_FPU_SW(thread) \
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(thread->td_pcb->pcb_save.sv_87.sv_env.en_sw)
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#define GET_FPU_EXSW_PTR(pcb) \
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(&(pcb)->pcb_save.sv_87.sv_ex_sw)
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#endif /* CPU_ENABLE_SSE */
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typedef u_char bool_t;
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@ -190,6 +185,8 @@ static volatile u_int npx_intrs_while_probing;
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static volatile u_int npx_traps_while_probing;
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#endif
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static union savefpu npx_cleanstate;
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static bool_t npx_cleanstate_ready;
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static bool_t npx_ex16;
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static bool_t npx_exists;
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static bool_t npx_irq13;
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@ -461,6 +458,7 @@ npx_attach(dev)
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device_t dev;
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{
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int flags;
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register_t s;
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if (resource_int_value("npx", 0, "flags", &flags) != 0)
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flags = 0;
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@ -497,6 +495,14 @@ npx_attach(dev)
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}
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npxinit(__INITIAL_NPXCW__);
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if (npx_cleanstate_ready == 0) {
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s = intr_disable();
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stop_emulating();
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fpusave(&npx_cleanstate);
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start_emulating();
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npx_cleanstate_ready = 1;
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intr_restore(s);
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}
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#ifdef I586_CPU_XXX
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if (cpu_class == CPUCLASS_586 && npx_ex16 && npx_exists &&
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timezero("i586_bzero()", i586_bzero) <
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@ -543,8 +549,6 @@ npxinit(control)
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fninit();
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#endif
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fldcw(&control);
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if (PCPU_GET(curpcb) != NULL)
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fpusave(&PCPU_GET(curpcb)->pcb_save);
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start_emulating();
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intr_restore(savecrit);
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}
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@ -559,15 +563,14 @@ npxexit(td)
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register_t savecrit;
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savecrit = intr_disable();
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if (td == PCPU_GET(fpcurthread))
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if (curthread == PCPU_GET(fpcurthread))
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npxsave(&PCPU_GET(curpcb)->pcb_save);
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intr_restore(savecrit);
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#ifdef NPX_DEBUG
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if (npx_exists) {
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u_int masked_exceptions;
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masked_exceptions = PCPU_GET(curpcb)->pcb_save.sv_87.sv_env.en_cw
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& PCPU_GET(curpcb)->pcb_save.sv_87.sv_env.en_sw & 0x7f;
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masked_exceptions = GET_FPU_CW(td) & GET_FPU_SW(td) & 0x7f;
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/*
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* Log exceptions that would have trapped with the old
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* control word (overflow, divide by 0, and invalid operand).
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@ -581,6 +584,19 @@ npxexit(td)
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#endif
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}
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int
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npxformat()
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{
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if (!npx_exists)
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return (_MC_FPFMT_NODEV);
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#ifdef CPU_ENABLE_SSE
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if (cpu_fxsr)
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return (_MC_FPFMT_XMM);
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#endif
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return (_MC_FPFMT_387);
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}
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/*
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* The following mechanism is used to ensure that the FPE_... value
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* that is passed as a trapcode to the signal handler of the user
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@ -774,7 +790,6 @@ npxtrap()
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{
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register_t savecrit;
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u_short control, status;
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u_long *exstat;
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if (!npx_exists) {
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printf("npxtrap: fpcurthread = %p, curthread = %p, npx_exists = %d\n",
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@ -796,11 +811,7 @@ npxtrap()
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fnstsw(&status);
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}
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exstat = GET_FPU_EXSW_PTR(curthread->td_pcb);
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*exstat = status;
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if (PCPU_GET(fpcurthread) != curthread)
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GET_FPU_SW(curthread) &= ~0x80bf;
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else
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if (PCPU_GET(fpcurthread) == curthread)
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fnclex();
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intr_restore(savecrit);
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return (fpetable[status & ((~control & 0x3f) | 0x40)]);
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@ -813,17 +824,29 @@ npxtrap()
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* and not necessarily for every context switch, but it is too hard to
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* access foreign pcb's.
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*/
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static int err_count = 0;
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int
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npxdna()
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{
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u_long *exstat;
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struct pcb *pcb;
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register_t s;
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u_short control;
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if (!npx_exists)
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return (0);
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if (PCPU_GET(fpcurthread) == curthread) {
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printf("npxdna: fpcurthread == curthread %d times\n",
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++err_count);
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stop_emulating();
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return (1);
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}
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if (PCPU_GET(fpcurthread) != NULL) {
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printf("npxdna: fpcurthread = %p, curthread = %p\n",
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PCPU_GET(fpcurthread), curthread);
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printf("npxdna: fpcurthread = %p (%d), curthread = %p (%d)\n",
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PCPU_GET(fpcurthread),
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PCPU_GET(fpcurthread)->td_proc->p_pid,
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curthread, curthread->td_proc->p_pid);
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panic("npxdna");
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}
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s = intr_disable();
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@ -832,22 +855,35 @@ npxdna()
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* Record new context early in case frstor causes an IRQ13.
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*/
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PCPU_SET(fpcurthread, curthread);
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pcb = PCPU_GET(curpcb);
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exstat = GET_FPU_EXSW_PTR(PCPU_GET(curpcb));
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*exstat = 0;
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/*
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* The following frstor may cause an IRQ13 when the state being
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* restored has a pending error. The error will appear to have been
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* triggered by the current (npx) user instruction even when that
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* instruction is a no-wait instruction that should not trigger an
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* error (e.g., fnclex). On at least one 486 system all of the
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* no-wait instructions are broken the same as frstor, so our
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* treatment does not amplify the breakage. On at least one
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* 386/Cyrix 387 system, fnclex works correctly while frstor and
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* fnsave are broken, so our treatment breaks fnclex if it is the
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* first FPU instruction after a context switch.
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*/
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fpurstor(&PCPU_GET(curpcb)->pcb_save);
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if ((pcb->pcb_flags & PCB_NPXINITDONE) == 0) {
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/*
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* This is the first time this thread has used the FPU or
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* the PCB doesn't contain a clean FPU state. Explicitly
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* initialize the FPU and load the default control word.
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*/
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fninit();
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control = __INITIAL_NPXCW__;
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fldcw(&control);
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pcb->pcb_flags |= PCB_NPXINITDONE;
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} else {
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/*
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* The following frstor may cause an IRQ13 when the state
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* being restored has a pending error. The error will
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* appear to have been triggered by the current (npx) user
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* instruction even when that instruction is a no-wait
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* instruction that should not trigger an error (e.g.,
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* fnclex). On at least one 486 system all of the no-wait
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* instructions are broken the same as frstor, so our
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* treatment does not amplify the breakage. On at least
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* one 386/Cyrix 387 system, fnclex works correctly while
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* frstor and fnsave are broken, so our treatment breaks
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* fnclex if it is the first FPU instruction after a context
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* switch.
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*/
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fpurstor(&pcb->pcb_save);
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}
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intr_restore(s);
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return (1);
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@ -888,6 +924,87 @@ npxsave(addr)
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PCPU_SET(fpcurthread, NULL);
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}
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/*
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* This should be called with interrupts disabled and only when the owning
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* FPU thread is non-null.
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*/
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void
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npxdrop()
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{
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struct thread *td;
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td = PCPU_GET(fpcurthread);
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PCPU_SET(fpcurthread, NULL);
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td->td_pcb->pcb_flags &= ~PCB_NPXINITDONE;
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start_emulating();
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}
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/*
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* Get the state of the FPU without dropping ownership (if possible).
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* It returns the FPU ownership status.
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*/
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int
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npxgetregs(td, addr)
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struct thread *td;
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union savefpu *addr;
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{
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register_t s;
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if (!npx_exists)
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return (_MC_FPOWNED_NONE);
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if ((td->td_pcb->pcb_flags & PCB_NPXINITDONE) == 0) {
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if (npx_cleanstate_ready)
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bcopy(&npx_cleanstate, addr, sizeof(npx_cleanstate));
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else
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bzero(addr, sizeof(*addr));
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return (_MC_FPOWNED_NONE);
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}
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s = intr_disable();
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if (curthread == PCPU_GET(fpcurthread)) {
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fpusave(addr);
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#ifdef CPU_ENABLE_SSE
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if (!cpu_fxsr)
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#endif
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/*
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* fnsave initializes the FPU and destroys whatever
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* context it contains. Make sure the FPU owner
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* starts with a clean state next time.
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*/
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npxdrop();
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intr_restore(s);
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return (_MC_FPOWNED_FPU);
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} else {
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intr_restore(s);
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bcopy(&td->td_pcb->pcb_save, addr, sizeof(*addr));
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return (_MC_FPOWNED_PCB);
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}
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}
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/*
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* Set the state of the FPU.
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*/
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void
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npxsetregs(td, addr)
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struct thread *td;
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union savefpu *addr;
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{
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register_t s;
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if (!npx_exists)
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return;
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s = intr_disable();
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if (curthread == PCPU_GET(fpcurthread)) {
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fpurstor(addr);
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intr_restore(s);
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} else {
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intr_restore(s);
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bcopy(addr, &td->td_pcb->pcb_save, sizeof(*addr));
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}
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}
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static void
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fpusave(addr)
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union savefpu *addr;
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@ -74,6 +74,7 @@
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#include <machine/resource.h>
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#include <machine/specialreg.h>
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#include <machine/segments.h>
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#include <machine/ucontext.h>
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#ifndef SMP
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#include <i386/isa/icu.h>
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@ -151,17 +152,11 @@ void stop_emulating(void);
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(cpu_fxsr ? \
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(thread)->td_pcb->pcb_save.sv_xmm.sv_env.en_sw : \
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(thread)->td_pcb->pcb_save.sv_87.sv_env.en_sw)
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#define GET_FPU_EXSW_PTR(pcb) \
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(cpu_fxsr ? \
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&(pcb)->pcb_save.sv_xmm.sv_ex_sw : \
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&(pcb)->pcb_save.sv_87.sv_ex_sw)
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#else /* CPU_ENABLE_SSE */
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#define GET_FPU_CW(thread) \
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(thread->td_pcb->pcb_save.sv_87.sv_env.en_cw)
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#define GET_FPU_SW(thread) \
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(thread->td_pcb->pcb_save.sv_87.sv_env.en_sw)
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#define GET_FPU_EXSW_PTR(pcb) \
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(&(pcb)->pcb_save.sv_87.sv_ex_sw)
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#endif /* CPU_ENABLE_SSE */
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typedef u_char bool_t;
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@ -190,6 +185,8 @@ static volatile u_int npx_intrs_while_probing;
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static volatile u_int npx_traps_while_probing;
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#endif
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static union savefpu npx_cleanstate;
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static bool_t npx_cleanstate_ready;
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static bool_t npx_ex16;
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static bool_t npx_exists;
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static bool_t npx_irq13;
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@ -461,6 +458,7 @@ npx_attach(dev)
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device_t dev;
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{
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int flags;
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register_t s;
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if (resource_int_value("npx", 0, "flags", &flags) != 0)
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flags = 0;
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@ -497,6 +495,14 @@ npx_attach(dev)
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}
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npxinit(__INITIAL_NPXCW__);
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if (npx_cleanstate_ready == 0) {
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s = intr_disable();
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stop_emulating();
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fpusave(&npx_cleanstate);
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start_emulating();
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npx_cleanstate_ready = 1;
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intr_restore(s);
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}
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#ifdef I586_CPU_XXX
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if (cpu_class == CPUCLASS_586 && npx_ex16 && npx_exists &&
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timezero("i586_bzero()", i586_bzero) <
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@ -543,8 +549,6 @@ npxinit(control)
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fninit();
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#endif
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fldcw(&control);
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if (PCPU_GET(curpcb) != NULL)
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fpusave(&PCPU_GET(curpcb)->pcb_save);
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start_emulating();
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intr_restore(savecrit);
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}
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@ -559,15 +563,14 @@ npxexit(td)
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register_t savecrit;
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savecrit = intr_disable();
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if (td == PCPU_GET(fpcurthread))
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if (curthread == PCPU_GET(fpcurthread))
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npxsave(&PCPU_GET(curpcb)->pcb_save);
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intr_restore(savecrit);
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#ifdef NPX_DEBUG
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if (npx_exists) {
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u_int masked_exceptions;
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masked_exceptions = PCPU_GET(curpcb)->pcb_save.sv_87.sv_env.en_cw
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& PCPU_GET(curpcb)->pcb_save.sv_87.sv_env.en_sw & 0x7f;
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masked_exceptions = GET_FPU_CW(td) & GET_FPU_SW(td) & 0x7f;
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/*
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* Log exceptions that would have trapped with the old
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* control word (overflow, divide by 0, and invalid operand).
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@ -581,6 +584,19 @@ npxexit(td)
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#endif
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}
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int
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npxformat()
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{
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if (!npx_exists)
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return (_MC_FPFMT_NODEV);
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#ifdef CPU_ENABLE_SSE
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if (cpu_fxsr)
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return (_MC_FPFMT_XMM);
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#endif
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return (_MC_FPFMT_387);
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}
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/*
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* The following mechanism is used to ensure that the FPE_... value
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* that is passed as a trapcode to the signal handler of the user
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@ -774,7 +790,6 @@ npxtrap()
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{
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register_t savecrit;
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u_short control, status;
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u_long *exstat;
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if (!npx_exists) {
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printf("npxtrap: fpcurthread = %p, curthread = %p, npx_exists = %d\n",
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@ -796,11 +811,7 @@ npxtrap()
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fnstsw(&status);
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}
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exstat = GET_FPU_EXSW_PTR(curthread->td_pcb);
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*exstat = status;
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if (PCPU_GET(fpcurthread) != curthread)
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GET_FPU_SW(curthread) &= ~0x80bf;
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else
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if (PCPU_GET(fpcurthread) == curthread)
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fnclex();
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intr_restore(savecrit);
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return (fpetable[status & ((~control & 0x3f) | 0x40)]);
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@ -813,17 +824,29 @@ npxtrap()
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* and not necessarily for every context switch, but it is too hard to
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* access foreign pcb's.
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*/
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static int err_count = 0;
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int
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npxdna()
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{
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u_long *exstat;
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struct pcb *pcb;
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register_t s;
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u_short control;
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if (!npx_exists)
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return (0);
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if (PCPU_GET(fpcurthread) == curthread) {
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printf("npxdna: fpcurthread == curthread %d times\n",
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++err_count);
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stop_emulating();
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return (1);
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}
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if (PCPU_GET(fpcurthread) != NULL) {
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printf("npxdna: fpcurthread = %p, curthread = %p\n",
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PCPU_GET(fpcurthread), curthread);
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printf("npxdna: fpcurthread = %p (%d), curthread = %p (%d)\n",
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PCPU_GET(fpcurthread),
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PCPU_GET(fpcurthread)->td_proc->p_pid,
|
||||
curthread, curthread->td_proc->p_pid);
|
||||
panic("npxdna");
|
||||
}
|
||||
s = intr_disable();
|
||||
@ -832,22 +855,35 @@ npxdna()
|
||||
* Record new context early in case frstor causes an IRQ13.
|
||||
*/
|
||||
PCPU_SET(fpcurthread, curthread);
|
||||
pcb = PCPU_GET(curpcb);
|
||||
|
||||
exstat = GET_FPU_EXSW_PTR(PCPU_GET(curpcb));
|
||||
*exstat = 0;
|
||||
/*
|
||||
* The following frstor may cause an IRQ13 when the state being
|
||||
* restored has a pending error. The error will appear to have been
|
||||
* triggered by the current (npx) user instruction even when that
|
||||
* instruction is a no-wait instruction that should not trigger an
|
||||
* error (e.g., fnclex). On at least one 486 system all of the
|
||||
* no-wait instructions are broken the same as frstor, so our
|
||||
* treatment does not amplify the breakage. On at least one
|
||||
* 386/Cyrix 387 system, fnclex works correctly while frstor and
|
||||
* fnsave are broken, so our treatment breaks fnclex if it is the
|
||||
* first FPU instruction after a context switch.
|
||||
*/
|
||||
fpurstor(&PCPU_GET(curpcb)->pcb_save);
|
||||
if ((pcb->pcb_flags & PCB_NPXINITDONE) == 0) {
|
||||
/*
|
||||
* This is the first time this thread has used the FPU or
|
||||
* the PCB doesn't contain a clean FPU state. Explicitly
|
||||
* initialize the FPU and load the default control word.
|
||||
*/
|
||||
fninit();
|
||||
control = __INITIAL_NPXCW__;
|
||||
fldcw(&control);
|
||||
pcb->pcb_flags |= PCB_NPXINITDONE;
|
||||
} else {
|
||||
/*
|
||||
* The following frstor may cause an IRQ13 when the state
|
||||
* being restored has a pending error. The error will
|
||||
* appear to have been triggered by the current (npx) user
|
||||
* instruction even when that instruction is a no-wait
|
||||
* instruction that should not trigger an error (e.g.,
|
||||
* fnclex). On at least one 486 system all of the no-wait
|
||||
* instructions are broken the same as frstor, so our
|
||||
* treatment does not amplify the breakage. On at least
|
||||
* one 386/Cyrix 387 system, fnclex works correctly while
|
||||
* frstor and fnsave are broken, so our treatment breaks
|
||||
* fnclex if it is the first FPU instruction after a context
|
||||
* switch.
|
||||
*/
|
||||
fpurstor(&pcb->pcb_save);
|
||||
}
|
||||
intr_restore(s);
|
||||
|
||||
return (1);
|
||||
@ -888,6 +924,87 @@ npxsave(addr)
|
||||
PCPU_SET(fpcurthread, NULL);
|
||||
}
|
||||
|
||||
/*
|
||||
* This should be called with interrupts disabled and only when the owning
|
||||
* FPU thread is non-null.
|
||||
*/
|
||||
void
|
||||
npxdrop()
|
||||
{
|
||||
struct thread *td;
|
||||
|
||||
td = PCPU_GET(fpcurthread);
|
||||
PCPU_SET(fpcurthread, NULL);
|
||||
td->td_pcb->pcb_flags &= ~PCB_NPXINITDONE;
|
||||
start_emulating();
|
||||
}
|
||||
|
||||
/*
|
||||
* Get the state of the FPU without dropping ownership (if possible).
|
||||
* It returns the FPU ownership status.
|
||||
*/
|
||||
int
|
||||
npxgetregs(td, addr)
|
||||
struct thread *td;
|
||||
union savefpu *addr;
|
||||
{
|
||||
register_t s;
|
||||
|
||||
if (!npx_exists)
|
||||
return (_MC_FPOWNED_NONE);
|
||||
|
||||
if ((td->td_pcb->pcb_flags & PCB_NPXINITDONE) == 0) {
|
||||
if (npx_cleanstate_ready)
|
||||
bcopy(&npx_cleanstate, addr, sizeof(npx_cleanstate));
|
||||
else
|
||||
bzero(addr, sizeof(*addr));
|
||||
return (_MC_FPOWNED_NONE);
|
||||
}
|
||||
|
||||
s = intr_disable();
|
||||
if (curthread == PCPU_GET(fpcurthread)) {
|
||||
fpusave(addr);
|
||||
#ifdef CPU_ENABLE_SSE
|
||||
if (!cpu_fxsr)
|
||||
#endif
|
||||
/*
|
||||
* fnsave initializes the FPU and destroys whatever
|
||||
* context it contains. Make sure the FPU owner
|
||||
* starts with a clean state next time.
|
||||
*/
|
||||
npxdrop();
|
||||
intr_restore(s);
|
||||
return (_MC_FPOWNED_FPU);
|
||||
} else {
|
||||
intr_restore(s);
|
||||
bcopy(&td->td_pcb->pcb_save, addr, sizeof(*addr));
|
||||
return (_MC_FPOWNED_PCB);
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* Set the state of the FPU.
|
||||
*/
|
||||
void
|
||||
npxsetregs(td, addr)
|
||||
struct thread *td;
|
||||
union savefpu *addr;
|
||||
{
|
||||
register_t s;
|
||||
|
||||
if (!npx_exists)
|
||||
return;
|
||||
|
||||
s = intr_disable();
|
||||
if (curthread == PCPU_GET(fpcurthread)) {
|
||||
fpurstor(addr);
|
||||
intr_restore(s);
|
||||
} else {
|
||||
intr_restore(s);
|
||||
bcopy(addr, &td->td_pcb->pcb_save, sizeof(*addr));
|
||||
}
|
||||
}
|
||||
|
||||
static void
|
||||
fpusave(addr)
|
||||
union savefpu *addr;
|
||||
|
||||
@ -74,6 +74,7 @@
|
||||
#include <machine/resource.h>
|
||||
#include <machine/specialreg.h>
|
||||
#include <machine/segments.h>
|
||||
#include <machine/ucontext.h>
|
||||
|
||||
#ifndef SMP
|
||||
#include <i386/isa/icu.h>
|
||||
@ -151,17 +152,11 @@ void stop_emulating(void);
|
||||
(cpu_fxsr ? \
|
||||
(thread)->td_pcb->pcb_save.sv_xmm.sv_env.en_sw : \
|
||||
(thread)->td_pcb->pcb_save.sv_87.sv_env.en_sw)
|
||||
#define GET_FPU_EXSW_PTR(pcb) \
|
||||
(cpu_fxsr ? \
|
||||
&(pcb)->pcb_save.sv_xmm.sv_ex_sw : \
|
||||
&(pcb)->pcb_save.sv_87.sv_ex_sw)
|
||||
#else /* CPU_ENABLE_SSE */
|
||||
#define GET_FPU_CW(thread) \
|
||||
(thread->td_pcb->pcb_save.sv_87.sv_env.en_cw)
|
||||
#define GET_FPU_SW(thread) \
|
||||
(thread->td_pcb->pcb_save.sv_87.sv_env.en_sw)
|
||||
#define GET_FPU_EXSW_PTR(pcb) \
|
||||
(&(pcb)->pcb_save.sv_87.sv_ex_sw)
|
||||
#endif /* CPU_ENABLE_SSE */
|
||||
|
||||
typedef u_char bool_t;
|
||||
@ -190,6 +185,8 @@ static volatile u_int npx_intrs_while_probing;
|
||||
static volatile u_int npx_traps_while_probing;
|
||||
#endif
|
||||
|
||||
static union savefpu npx_cleanstate;
|
||||
static bool_t npx_cleanstate_ready;
|
||||
static bool_t npx_ex16;
|
||||
static bool_t npx_exists;
|
||||
static bool_t npx_irq13;
|
||||
@ -461,6 +458,7 @@ npx_attach(dev)
|
||||
device_t dev;
|
||||
{
|
||||
int flags;
|
||||
register_t s;
|
||||
|
||||
if (resource_int_value("npx", 0, "flags", &flags) != 0)
|
||||
flags = 0;
|
||||
@ -497,6 +495,14 @@ npx_attach(dev)
|
||||
}
|
||||
npxinit(__INITIAL_NPXCW__);
|
||||
|
||||
if (npx_cleanstate_ready == 0) {
|
||||
s = intr_disable();
|
||||
stop_emulating();
|
||||
fpusave(&npx_cleanstate);
|
||||
start_emulating();
|
||||
npx_cleanstate_ready = 1;
|
||||
intr_restore(s);
|
||||
}
|
||||
#ifdef I586_CPU_XXX
|
||||
if (cpu_class == CPUCLASS_586 && npx_ex16 && npx_exists &&
|
||||
timezero("i586_bzero()", i586_bzero) <
|
||||
@ -543,8 +549,6 @@ npxinit(control)
|
||||
fninit();
|
||||
#endif
|
||||
fldcw(&control);
|
||||
if (PCPU_GET(curpcb) != NULL)
|
||||
fpusave(&PCPU_GET(curpcb)->pcb_save);
|
||||
start_emulating();
|
||||
intr_restore(savecrit);
|
||||
}
|
||||
@ -559,15 +563,14 @@ npxexit(td)
|
||||
register_t savecrit;
|
||||
|
||||
savecrit = intr_disable();
|
||||
if (td == PCPU_GET(fpcurthread))
|
||||
if (curthread == PCPU_GET(fpcurthread))
|
||||
npxsave(&PCPU_GET(curpcb)->pcb_save);
|
||||
intr_restore(savecrit);
|
||||
#ifdef NPX_DEBUG
|
||||
if (npx_exists) {
|
||||
u_int masked_exceptions;
|
||||
|
||||
masked_exceptions = PCPU_GET(curpcb)->pcb_save.sv_87.sv_env.en_cw
|
||||
& PCPU_GET(curpcb)->pcb_save.sv_87.sv_env.en_sw & 0x7f;
|
||||
masked_exceptions = GET_FPU_CW(td) & GET_FPU_SW(td) & 0x7f;
|
||||
/*
|
||||
* Log exceptions that would have trapped with the old
|
||||
* control word (overflow, divide by 0, and invalid operand).
|
||||
@ -581,6 +584,19 @@ npxexit(td)
|
||||
#endif
|
||||
}
|
||||
|
||||
int
|
||||
npxformat()
|
||||
{
|
||||
|
||||
if (!npx_exists)
|
||||
return (_MC_FPFMT_NODEV);
|
||||
#ifdef CPU_ENABLE_SSE
|
||||
if (cpu_fxsr)
|
||||
return (_MC_FPFMT_XMM);
|
||||
#endif
|
||||
return (_MC_FPFMT_387);
|
||||
}
|
||||
|
||||
/*
|
||||
* The following mechanism is used to ensure that the FPE_... value
|
||||
* that is passed as a trapcode to the signal handler of the user
|
||||
@ -774,7 +790,6 @@ npxtrap()
|
||||
{
|
||||
register_t savecrit;
|
||||
u_short control, status;
|
||||
u_long *exstat;
|
||||
|
||||
if (!npx_exists) {
|
||||
printf("npxtrap: fpcurthread = %p, curthread = %p, npx_exists = %d\n",
|
||||
@ -796,11 +811,7 @@ npxtrap()
|
||||
fnstsw(&status);
|
||||
}
|
||||
|
||||
exstat = GET_FPU_EXSW_PTR(curthread->td_pcb);
|
||||
*exstat = status;
|
||||
if (PCPU_GET(fpcurthread) != curthread)
|
||||
GET_FPU_SW(curthread) &= ~0x80bf;
|
||||
else
|
||||
if (PCPU_GET(fpcurthread) == curthread)
|
||||
fnclex();
|
||||
intr_restore(savecrit);
|
||||
return (fpetable[status & ((~control & 0x3f) | 0x40)]);
|
||||
@ -813,17 +824,29 @@ npxtrap()
|
||||
* and not necessarily for every context switch, but it is too hard to
|
||||
* access foreign pcb's.
|
||||
*/
|
||||
|
||||
static int err_count = 0;
|
||||
|
||||
int
|
||||
npxdna()
|
||||
{
|
||||
u_long *exstat;
|
||||
struct pcb *pcb;
|
||||
register_t s;
|
||||
u_short control;
|
||||
|
||||
if (!npx_exists)
|
||||
return (0);
|
||||
if (PCPU_GET(fpcurthread) == curthread) {
|
||||
printf("npxdna: fpcurthread == curthread %d times\n",
|
||||
++err_count);
|
||||
stop_emulating();
|
||||
return (1);
|
||||
}
|
||||
if (PCPU_GET(fpcurthread) != NULL) {
|
||||
printf("npxdna: fpcurthread = %p, curthread = %p\n",
|
||||
PCPU_GET(fpcurthread), curthread);
|
||||
printf("npxdna: fpcurthread = %p (%d), curthread = %p (%d)\n",
|
||||
PCPU_GET(fpcurthread),
|
||||
PCPU_GET(fpcurthread)->td_proc->p_pid,
|
||||
curthread, curthread->td_proc->p_pid);
|
||||
panic("npxdna");
|
||||
}
|
||||
s = intr_disable();
|
||||
@ -832,22 +855,35 @@ npxdna()
|
||||
* Record new context early in case frstor causes an IRQ13.
|
||||
*/
|
||||
PCPU_SET(fpcurthread, curthread);
|
||||
pcb = PCPU_GET(curpcb);
|
||||
|
||||
exstat = GET_FPU_EXSW_PTR(PCPU_GET(curpcb));
|
||||
*exstat = 0;
|
||||
/*
|
||||
* The following frstor may cause an IRQ13 when the state being
|
||||
* restored has a pending error. The error will appear to have been
|
||||
* triggered by the current (npx) user instruction even when that
|
||||
* instruction is a no-wait instruction that should not trigger an
|
||||
* error (e.g., fnclex). On at least one 486 system all of the
|
||||
* no-wait instructions are broken the same as frstor, so our
|
||||
* treatment does not amplify the breakage. On at least one
|
||||
* 386/Cyrix 387 system, fnclex works correctly while frstor and
|
||||
* fnsave are broken, so our treatment breaks fnclex if it is the
|
||||
* first FPU instruction after a context switch.
|
||||
*/
|
||||
fpurstor(&PCPU_GET(curpcb)->pcb_save);
|
||||
if ((pcb->pcb_flags & PCB_NPXINITDONE) == 0) {
|
||||
/*
|
||||
* This is the first time this thread has used the FPU or
|
||||
* the PCB doesn't contain a clean FPU state. Explicitly
|
||||
* initialize the FPU and load the default control word.
|
||||
*/
|
||||
fninit();
|
||||
control = __INITIAL_NPXCW__;
|
||||
fldcw(&control);
|
||||
pcb->pcb_flags |= PCB_NPXINITDONE;
|
||||
} else {
|
||||
/*
|
||||
* The following frstor may cause an IRQ13 when the state
|
||||
* being restored has a pending error. The error will
|
||||
* appear to have been triggered by the current (npx) user
|
||||
* instruction even when that instruction is a no-wait
|
||||
* instruction that should not trigger an error (e.g.,
|
||||
* fnclex). On at least one 486 system all of the no-wait
|
||||
* instructions are broken the same as frstor, so our
|
||||
* treatment does not amplify the breakage. On at least
|
||||
* one 386/Cyrix 387 system, fnclex works correctly while
|
||||
* frstor and fnsave are broken, so our treatment breaks
|
||||
* fnclex if it is the first FPU instruction after a context
|
||||
* switch.
|
||||
*/
|
||||
fpurstor(&pcb->pcb_save);
|
||||
}
|
||||
intr_restore(s);
|
||||
|
||||
return (1);
|
||||
@ -888,6 +924,87 @@ npxsave(addr)
|
||||
PCPU_SET(fpcurthread, NULL);
|
||||
}
|
||||
|
||||
/*
|
||||
* This should be called with interrupts disabled and only when the owning
|
||||
* FPU thread is non-null.
|
||||
*/
|
||||
void
|
||||
npxdrop()
|
||||
{
|
||||
struct thread *td;
|
||||
|
||||
td = PCPU_GET(fpcurthread);
|
||||
PCPU_SET(fpcurthread, NULL);
|
||||
td->td_pcb->pcb_flags &= ~PCB_NPXINITDONE;
|
||||
start_emulating();
|
||||
}
|
||||
|
||||
/*
|
||||
* Get the state of the FPU without dropping ownership (if possible).
|
||||
* It returns the FPU ownership status.
|
||||
*/
|
||||
int
|
||||
npxgetregs(td, addr)
|
||||
struct thread *td;
|
||||
union savefpu *addr;
|
||||
{
|
||||
register_t s;
|
||||
|
||||
if (!npx_exists)
|
||||
return (_MC_FPOWNED_NONE);
|
||||
|
||||
if ((td->td_pcb->pcb_flags & PCB_NPXINITDONE) == 0) {
|
||||
if (npx_cleanstate_ready)
|
||||
bcopy(&npx_cleanstate, addr, sizeof(npx_cleanstate));
|
||||
else
|
||||
bzero(addr, sizeof(*addr));
|
||||
return (_MC_FPOWNED_NONE);
|
||||
}
|
||||
|
||||
s = intr_disable();
|
||||
if (curthread == PCPU_GET(fpcurthread)) {
|
||||
fpusave(addr);
|
||||
#ifdef CPU_ENABLE_SSE
|
||||
if (!cpu_fxsr)
|
||||
#endif
|
||||
/*
|
||||
* fnsave initializes the FPU and destroys whatever
|
||||
* context it contains. Make sure the FPU owner
|
||||
* starts with a clean state next time.
|
||||
*/
|
||||
npxdrop();
|
||||
intr_restore(s);
|
||||
return (_MC_FPOWNED_FPU);
|
||||
} else {
|
||||
intr_restore(s);
|
||||
bcopy(&td->td_pcb->pcb_save, addr, sizeof(*addr));
|
||||
return (_MC_FPOWNED_PCB);
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* Set the state of the FPU.
|
||||
*/
|
||||
void
|
||||
npxsetregs(td, addr)
|
||||
struct thread *td;
|
||||
union savefpu *addr;
|
||||
{
|
||||
register_t s;
|
||||
|
||||
if (!npx_exists)
|
||||
return;
|
||||
|
||||
s = intr_disable();
|
||||
if (curthread == PCPU_GET(fpcurthread)) {
|
||||
fpurstor(addr);
|
||||
intr_restore(s);
|
||||
} else {
|
||||
intr_restore(s);
|
||||
bcopy(addr, &td->td_pcb->pcb_save, sizeof(*addr));
|
||||
}
|
||||
}
|
||||
|
||||
static void
|
||||
fpusave(addr)
|
||||
union savefpu *addr;
|
||||
|
||||
Loading…
Reference in New Issue
Block a user