svn commit: r367416 - in head/sys/powerpc: include powerpc
Alfredo Dal'Ava Junior
alfredo at FreeBSD.org
Fri Nov 6 13:34:31 UTC 2020
Author: alfredo
Date: Fri Nov 6 13:34:30 2020
New Revision: 367416
URL: https://svnweb.freebsd.org/changeset/base/367416
Log:
[POWERPC] Floating-Point Exception trap support
Add support for Floating-Point Exception traps on 32 and 64 bit platforms.
Also make sure to clean FPSCR on EXEC and thread exit
Author of initial version: Renato Riolino <renato.riolino at eldorad.org.br>
Reviewed by: jhibbits
Sponsored by: Eldorado Research Institute (eldorado.org.br)
Differential Revision: https://reviews.freebsd.org/D23623
Modified:
head/sys/powerpc/include/cpufunc.h
head/sys/powerpc/include/fpu.h
head/sys/powerpc/include/psl.h
head/sys/powerpc/powerpc/exec_machdep.c
head/sys/powerpc/powerpc/fpu.c
head/sys/powerpc/powerpc/trap.c
Modified: head/sys/powerpc/include/cpufunc.h
==============================================================================
--- head/sys/powerpc/include/cpufunc.h Fri Nov 6 07:16:21 2020 (r367415)
+++ head/sys/powerpc/include/cpufunc.h Fri Nov 6 13:34:30 2020 (r367416)
@@ -163,6 +163,25 @@ mttb(u_quad_t time)
mtspr(TBR_TBWL, (uint32_t)(time & 0xffffffff));
}
+
+static __inline register_t
+mffs(void)
+{
+ register_t value;
+
+ __asm __volatile ("mffs 0; stfd 0,0(%0)"
+ :: "b"(&value));
+
+ return (value);
+}
+
+static __inline void
+mtfsf(register_t value)
+{
+ __asm __volatile ("lfd 0,0(%0); mtfsf 0xff,0"
+ :: "b"(&value));
+}
+
static __inline void
eieio(void)
{
Modified: head/sys/powerpc/include/fpu.h
==============================================================================
--- head/sys/powerpc/include/fpu.h Fri Nov 6 07:16:21 2020 (r367415)
+++ head/sys/powerpc/include/fpu.h Fri Nov 6 13:34:30 2020 (r367416)
@@ -75,6 +75,8 @@
void enable_fpu(struct thread *);
void save_fpu(struct thread *);
void save_fpu_nodrop(struct thread *);
+void cleanup_fpscr(void);
+u_int get_fpu_exception(struct thread *);
#endif /* _KERNEL */
Modified: head/sys/powerpc/include/psl.h
==============================================================================
--- head/sys/powerpc/include/psl.h Fri Nov 6 07:16:21 2020 (r367415)
+++ head/sys/powerpc/include/psl.h Fri Nov 6 13:34:30 2020 (r367416)
@@ -88,7 +88,7 @@
#define PSL_FE_NONREC PSL_FE1 /* imprecise non-recoverable */
#define PSL_FE_REC PSL_FE0 /* imprecise recoverable */
#define PSL_FE_PREC (PSL_FE0 | PSL_FE1) /* precise */
-#define PSL_FE_DFLT PSL_FE_DIS /* default == none */
+#define PSL_FE_DFLT PSL_FE_PREC /* default == precise */
#ifndef LOCORE
extern register_t psl_kernset; /* Default MSR values for kernel */
Modified: head/sys/powerpc/powerpc/exec_machdep.c
==============================================================================
--- head/sys/powerpc/powerpc/exec_machdep.c Fri Nov 6 07:16:21 2020 (r367415)
+++ head/sys/powerpc/powerpc/exec_machdep.c Fri Nov 6 13:34:30 2020 (r367416)
@@ -239,11 +239,14 @@ sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask
usfp = (void *)((sp - rndfsize) & ~0xFul);
}
- /*
- * Save the floating-point state, if necessary, then copy it.
+ /*
+ * Set Floating Point facility to "Ignore Exceptions Mode" so signal
+ * handler can run.
*/
- /* XXX */
+ if (td->td_pcb->pcb_flags & PCB_FPU)
+ tf->srr1 = tf->srr1 & ~(PSL_FE0 | PSL_FE1);
+
/*
* Set up the registers to return to sigcode.
*
@@ -333,6 +336,13 @@ sys_sigreturn(struct thread *td, struct sigreturn_args
kern_sigprocmask(td, SIG_SETMASK, &uc.uc_sigmask, NULL, 0);
+ /*
+ * Save FPU state if needed. User may have changed it on
+ * signal handler
+ */
+ if (uc.uc_mcontext.mc_srr1 & PSL_FP)
+ save_fpu(td);
+
CTR3(KTR_SIG, "sigreturn: return td=%p pc=%#x sp=%#x",
td, uc.uc_mcontext.mc_srr0, uc.uc_mcontext.mc_gpr[1]);
@@ -556,6 +566,8 @@ cleanup_power_extras(struct thread *td)
mtspr(SPR_FSCR, 0);
if (pcb_flags & PCB_CDSCR)
mtspr(SPR_DSCRP, 0);
+
+ cleanup_fpscr();
}
/*
@@ -825,6 +837,14 @@ freebsd32_sigreturn(struct thread *td, struct freebsd3
return (error);
kern_sigprocmask(td, SIG_SETMASK, &uc.uc_sigmask, NULL, 0);
+
+ /*
+ * Save FPU state if needed. User may have changed it on
+ * signal handler
+ */
+ if (uc.uc_mcontext.mc_srr1 & PSL_FP)
+ save_fpu(td);
+
CTR3(KTR_SIG, "sigreturn: return td=%p pc=%#x sp=%#x",
td, uc.uc_mcontext.mc_srr0, uc.uc_mcontext.mc_gpr[1]);
Modified: head/sys/powerpc/powerpc/fpu.c
==============================================================================
--- head/sys/powerpc/powerpc/fpu.c Fri Nov 6 07:16:21 2020 (r367415)
+++ head/sys/powerpc/powerpc/fpu.c Fri Nov 6 13:34:30 2020 (r367416)
@@ -48,7 +48,7 @@ __FBSDID("$FreeBSD$");
static void
save_fpu_int(struct thread *td)
{
- int msr;
+ register_t msr;
struct pcb *pcb;
pcb = td->td_pcb;
@@ -102,7 +102,7 @@ save_fpu_int(struct thread *td)
void
enable_fpu(struct thread *td)
{
- int msr;
+ register_t msr;
struct pcb *pcb;
struct trapframe *tf;
@@ -208,3 +208,58 @@ save_fpu_nodrop(struct thread *td)
if (td == PCPU_GET(fputhread))
save_fpu_int(td);
}
+
+
+/*
+ * Clear Floating-Point Status and Control Register
+ */
+void
+cleanup_fpscr()
+{
+ register_t msr;
+ msr = mfmsr();
+ mtmsr(msr | PSL_FP | PSL_VSX);
+
+ mtfsf(0);
+
+ isync();
+ mtmsr(msr);
+}
+
+
+/*
+ * * Returns the current fp exception
+ * */
+u_int
+get_fpu_exception(struct thread *td)
+{
+ register_t msr;
+ u_int ucode;
+ register_t reg;
+
+ critical_enter();
+
+ msr = mfmsr();
+ mtmsr(msr | PSL_FP);
+
+ reg = mffs();
+
+ isync();
+ mtmsr(msr);
+
+ critical_exit();
+
+ if (reg & FPSCR_ZX)
+ ucode = FPE_FLTDIV;
+ else if (reg & FPSCR_OX)
+ ucode = FPE_FLTOVF;
+ else if (reg & FPSCR_UX)
+ ucode = FPE_FLTUND;
+ else if (reg & FPSCR_XX)
+ ucode = FPE_FLTRES;
+ else
+ ucode = FPE_FLTINV;
+
+ return ucode;
+}
+
Modified: head/sys/powerpc/powerpc/trap.c
==============================================================================
--- head/sys/powerpc/powerpc/trap.c Fri Nov 6 07:16:21 2020 (r367415)
+++ head/sys/powerpc/powerpc/trap.c Fri Nov 6 13:34:30 2020 (r367416)
@@ -405,16 +405,24 @@ trap(struct trapframe *frame)
#endif
sig = SIGTRAP;
ucode = TRAP_BRKPT;
- } else {
+ break;
+ }
+
+ if ((frame->srr1 & EXC_PGM_FPENABLED) &&
+ (td->td_pcb->pcb_flags & PCB_FPU))
+ sig = SIGFPE;
+ else
sig = ppc_instr_emulate(frame, td);
- if (sig == SIGILL) {
- if (frame->srr1 & EXC_PGM_PRIV)
- ucode = ILL_PRVOPC;
- else if (frame->srr1 & EXC_PGM_ILLEGAL)
- ucode = ILL_ILLOPC;
- } else if (sig == SIGFPE)
- ucode = FPE_FLTINV; /* Punt for now, invalid operation. */
+
+ if (sig == SIGILL) {
+ if (frame->srr1 & EXC_PGM_PRIV)
+ ucode = ILL_PRVOPC;
+ else if (frame->srr1 & EXC_PGM_ILLEGAL)
+ ucode = ILL_ILLOPC;
+ } else if (sig == SIGFPE) {
+ ucode = get_fpu_exception(td);
}
+
break;
case EXC_MCHK:
@@ -964,7 +972,7 @@ fix_unaligned(struct thread *td, struct trapframe *fra
static void
normalize_inputs(void)
{
- unsigned long msr;
+ register_t msr;
/* enable VSX */
msr = mfmsr();
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