o Speedup syscalls. Now 816ns per syscall. Yes, nanoseconds and goodbye

   Pentium :-)
 o Little bit smarter handling of unimplemented exceptions.
 o Fix FPU context switches.
 o Fix reboot / halt.  Powerdown in software still doesn't work.
 o Fix the fix for handling of return values of interrupted syscalls.
 o Handling of the Indy second level cache now works as spec'ed.  Purely
   cosmentic, this was not causing any problems.

1 files changed, 31 insertions, 28 deletions

diff --git a/arch/mips/kernel/irixsig.c b/arch/mips/kernel/irixsig.c
index 88fca61f2..d0e286def 100644
--- a/arch/mips/kernel/irixsig.c
+++ b/arch/mips/kernel/irixsig.c
@@ -1,7 +1,9 @@
-/* $Id: irixsig.c,v 1.9 1998/03/17 00:59:35 ralf Exp $
+/*
  * irixsig.c: WHEEE, IRIX signals!  YOW, am I compatable or what?!?!
  *
  * Copyright (C) 1996 David S. Miller (dm@engr.sgi.com)
+ *
+ * $Id: irixsig.c,v 1.11 1998/03/26 07:39:09 ralf Exp $
  */
 
 #include <linux/kernel.h>
@@ -154,30 +156,27 @@ static inline void handle_signal(unsigned long sig, struct k_sigaction *ka,
 	}
 }
 
-static inline void syscall_restart(unsigned long r0, unsigned long or2,
-                                   unsigned long or7, struct pt_regs *regs,
-                                   struct sigaction *sa)
+static inline void syscall_restart(struct pt_regs *regs, struct k_sigaction *ka)
 {
-	switch(r0) {
+	switch(regs->regs[0]) {
 	case ERESTARTNOHAND:
-	no_system_call_restart:
-		regs->regs[0] = regs->regs[2] = EINTR;
+		regs->regs[2] = EINTR;
 		break;
 	case ERESTARTSYS:
-		if(!(sa->sa_flags & SA_RESTART))
-			goto no_system_call_restart;
+		if(!(ka->sa.sa_flags & SA_RESTART)) {
+			regs->regs[2] = EINTR;
+			break;
+		}
 	/* fallthrough */
-	case ERESTARTNOINTR:
-		regs->regs[0] = regs->regs[2] = or2;
-		regs->regs[7] = or7;
-	regs->cp0_epc -= 8;
+	case ERESTARTNOINTR:		/* Userland will reload $v0.  */
+		regs->cp0_epc -= 8;
 	}
+
+	regs->regs[0] = 0;		/* Don't deal with this again.  */
 }
 
 asmlinkage int do_irix_signal(sigset_t *oldset, struct pt_regs *regs)
 {
-	unsigned long r0 = regs->regs[0];
-	unsigned long r7 = regs->orig_reg7;
 	struct k_sigaction *ka;
 	siginfo_t info;
 
@@ -279,8 +278,8 @@ asmlinkage int do_irix_signal(sigset_t *oldset, struct pt_regs *regs)
 			}
 		}
 
-		if (r0)
-			syscall_restart(r0, regs->orig_reg2, r7, regs, &ka->sa);
+		if (regs->regs[0])
+			syscall_restart(regs, ka);
 		/* Whee!  Actually deliver the signal.  */
 		handle_signal(signr, ka, &info, oldset, regs);
 		return 1;
@@ -291,13 +290,12 @@ asmlinkage int do_irix_signal(sigset_t *oldset, struct pt_regs *regs)
 	 * dies here!!!  The li instruction, a single machine instruction,
 	 * must directly be followed by the syscall instruction.
 	 */
-	if (r0 &&
-	    (regs->regs[2] == ERESTARTNOHAND ||
-	     regs->regs[2] == ERESTARTSYS ||
-	     regs->regs[2] == ERESTARTNOINTR)) {
-		regs->regs[0] = regs->regs[2] = regs->orig_reg2;
-		regs->regs[7] = r7;
-		regs->cp0_epc -= 8;
+	if (regs->regs[0]) {
+		if (regs->regs[2] == ERESTARTNOHAND ||
+		    regs->regs[2] == ERESTARTSYS ||
+		    regs->regs[2] == ERESTARTNOINTR) {
+			regs->cp0_epc -= 8;
+		}
 	}
 	return 0;
 }
@@ -356,10 +354,15 @@ asmlinkage unsigned long irix_sigreturn(struct pt_regs *regs)
 	recalc_sigpending(current);
 	spin_unlock_irq(&current->sigmask_lock);
 
-	regs->orig_reg2 = -1;
-	__get_user(res, &context->regs[2]);
-
-	return res;
+	/*
+	 * Don't let your children do this ...
+	 */
+	__asm__ __volatile__(
+		"move\t$29,%0\n\t"
+		"j\tret_from_sys_call"
+		:/* no outputs */
+		:"r" (&regs));
+		/* Unreached */
 
 badframe:
 	lock_kernel();