sync with 9

Reference: /n/patches.lsub.org/patch/plan9-20120424
Date: Tue Apr 24 20:36:22 CES 2012
Signed-off-by: nemo@lsub.org

--- /sys/src/9/pc/dat.h	Thu Apr 19 15:29:43 2012
+++ /sys/src/9/pc/dat.h	Tue Apr 24 19:46:06 2012
@@ -2,8 +2,7 @@
 typedef struct BIOS32ci	BIOS32ci;
 typedef struct Conf	Conf;
 typedef struct Confmem	Confmem;
-typedef union FPanystate FPanystate;
-typedef struct FPsave	FPsave;
+typedef union FPsave	FPsave;
 typedef struct FPssestate FPssestate;
 typedef struct FPstate	FPstate;
 typedef struct ISAConf	ISAConf;
@@ -87,7 +86,7 @@
 	uchar	regs[80];	/* floating point registers */
 };
 
-struct	FPssestate			/* SSE fp state */
+struct	FPssestate		/* SSE fp state */
 {
 	ushort	fcw;		/* control */
 	ushort	fsw;		/* status */
@@ -102,19 +101,18 @@
 	ulong	mxcsr;		/* MXCSR register state */
 	ulong	mxcsr_mask;	/* MXCSR mask register */
 	uchar	xregs[480];	/* extended registers */
+	uchar	alignpad[FPalign];
 };
 
-#define FPalign	16	/* required for FXSAVE */
-
-union FPanystate {
+/*
+ * the FP regs must be stored here, not somewhere pointed to from here.
+ * port code assumes this.
+ */
+union FPsave {
 	FPstate;
 	FPssestate;
 };
 
-struct FPsave {
-	FPanystate *addr;	/* addr of fp state if it is alloced */ 
-};
-
 struct Confmem
 {
 	ulong	base;
@@ -256,6 +254,7 @@
 	uvlong	tscticks;
 	int	pdballoc;
 	int	pdbfree;
+	FPsave	*fpsavalign;
 
 	vlong	mtrrcap;
 	vlong	mtrrdef;
--- /sys/src/9/pc/fns.h	Thu Apr 19 15:29:43 2012
+++ /sys/src/9/pc/fns.h	Tue Apr 24 19:46:06 2012
@@ -34,7 +34,9 @@
 void	(*fprestore)(FPsave*);
 void	(*fpsave)(FPsave*);
 void	fpsserestore(FPsave*);
+void	fpsserestore0(FPsave*);
 void	fpssesave(FPsave*);
+void	fpssesave0(FPsave*);
 ulong	fpstatus(void);
 void	fpx87restore(FPsave*);
 void	fpx87save(FPsave*);
--- /sys/src/9/pc/l.s	Thu Apr 19 15:29:43 2012
+++ /sys/src/9/pc/l.s	Tue Apr 24 19:46:06 2012
@@ -784,19 +784,15 @@
 	WAIT
 	RET
 
-/* fpx87save(&fpstateptr) */
 TEXT fpx87save(SB), $0				/* save state and disable */
 	MOVL	p+0(FP), AX			/* points to pointer */
-	MOVL	(AX), AX			/* now points to state buffer */
 	FSAVE	0(AX)				/* no WAIT */
 	FPOFF
 	RET
 
-/* fpx87restore(&fpstateptr) */
 TEXT fpx87restore(SB), $0			/* enable and restore state */
 	FPON
-	MOVL	p+0(FP), AX			/* points to pointer */
-	MOVL	(AX), AX			/* now points to state buffer */
+	MOVL	p+0(FP), AX
 	FRSTOR	0(AX)
 	WAIT
 	RET
@@ -805,10 +801,8 @@
 	FSTSW	AX
 	RET
 
-/* fpenv(&fpstateptr) */
 TEXT fpenv(SB), $0				/* save state without waiting */
-	MOVL	p+0(FP), AX			/* points to pointer */
-	MOVL	(AX), AX			/* now points to state buffer */
+	MOVL	p+0(FP), AX
 	FSTENV	0(AX)
 	RET
 
@@ -818,19 +812,15 @@
 	FPOFF
 	RET
 
-/* fpssesave(&fpstateptr) */
-TEXT fpssesave(SB), $0				/* save state and disable */
-	MOVL	p+0(FP), AX			/* points to pointer */
-	MOVL	(AX), AX			/* now points to state buffer */
+TEXT fpssesave0(SB), $0				/* save state and disable */
+	MOVL	p+0(FP), AX
 	FXSAVE					/* no WAIT */
 	FPOFF
 	RET
 
-/* fpsserestore(&fpstateptr) */
-TEXT fpsserestore(SB), $0				/* enable and restore state */
+TEXT fpsserestore0(SB), $0			/* enable and restore state */
 	FPON
-	MOVL	p+0(FP), AX			/* points to pointer */
-	MOVL	(AX), AX			/* now points to state buffer */
+	MOVL	p+0(FP), AX
 	FXRSTOR
 	WAIT
 	RET
--- /sys/src/9/pc/main.c	Thu Apr 19 15:29:43 2012
+++ /sys/src/9/pc/main.c	Thu Apr 26 11:32:46 2012
@@ -466,10 +466,10 @@
 };
 
 static void
-mathstate(ulong *status, ulong *pc, ulong *control)
+mathstate(ulong *stsp, ulong *pcp, ulong *ctlp)
 {
 	ulong sts, fpc, ctl;
-	FPanystate *f = (FPanystate *)up->fpsave.addr;
+	FPsave *f = &up->fpsave;
 
 	if(fpsave == fpx87save){
 		sts = f->status;
@@ -480,12 +480,12 @@
 		fpc = f->fpuip;
 		ctl = f->fcw;
 	}
-	if(status)
-		*status = sts;
-	if(pc)
-		*pc = fpc;
-	if(control)
-		*control = ctl;
+	if(stsp)
+		*stsp = sts;
+	if(pcp)
+		*pcp = fpc;
+	if(ctlp)
+		*ctlp = ctl;
 }
 
 static void
@@ -517,28 +517,46 @@
 		}else
 			msg = "invalid operation";
 	}
-	snprint(note, sizeof note, "sys: fp: %s fppc=0x%lux status=0x%lux",
+	snprint(note, sizeof note, "sys: fp: %s fppc=%#lux status=%#lux",
 		msg, pc, status);
 	postnote(up, 1, note, NDebug);
 }
 
-static void
-fpexit(void)
+/*
+ * sse fp save and restore buffers have to be 16-byte (FPalign) aligned,
+ * so we shuffle the data up and down as needed or make copies.
+ */
+
+void
+fpssesave(FPsave *fps)
 {
-	free(up->fpsave.addr);
-	up->fpsave.addr = nil;
+	FPsave *afps;
+
+	afps = (FPsave *)ROUND(((uintptr)fps), FPalign);
+	fpssesave0(afps);
+	if (fps != afps)  /* not aligned? shuffle down from aligned buffer */
+		memmove(fps, afps, sizeof(FPssestate) - FPalign);
 }
 
-static void*
-fpalloc(void)
+void
+fpsserestore(FPsave *fps)
 {
-	if(up->fpsave.addr == nil) {
-		up->fpsave.addr = fpsave == fpx87save? smalloc(sizeof(FPstate)):
-			mallocalign(sizeof(FPssestate), FPalign, 0, 0);
-		if (up->fpsave.addr)
-			up->fpexit = fpexit;
-	}
-	return up->fpsave.addr;
+	FPsave *afps;
+
+	afps = (FPsave *)ROUND(((uintptr)fps), FPalign);
+	if (fps != afps) {
+		if (m->fpsavalign == nil)
+			m->fpsavalign = mallocalign(sizeof(FPssestate),
+				FPalign, 0, 0);
+		if (m->fpsavalign)
+			afps = m->fpsavalign;
+		/* copy or shuffle up to make aligned */
+		memmove(afps, fps, sizeof(FPssestate) - FPalign);
+	}
+	fpsserestore0(afps);
+	/* if we couldn't make a copy, shuffle regs back down */
+	if (fps != afps && afps != m->fpsavalign)
+		memmove(fps, afps, sizeof(FPssestate) - FPalign);
 }
 
 /*
@@ -556,8 +574,6 @@
 	if(!(m->cpuiddx & 0x01))
 		outb(0xF0, 0xFF);
 
-	fpalloc();
-
 	/*
 	 *  save floating point state to check out error
 	 */
@@ -585,7 +601,6 @@
 	}
 	switch(up->fpstate){
 	case FPinit:
-		fpalloc();
 		fpinit();
 		up->fpstate = FPactive;
 		break;
@@ -606,7 +621,7 @@
 		up->fpstate = FPactive;
 		break;
 	case FPactive:
-		panic("math emu pid %ld %s pc 0x%lux", 
+		panic("math emu pid %ld %s pc %#lux",
 			up->pid, up->text, ureg->pc);
 		break;
 	}
@@ -674,8 +689,7 @@
 			 * until the process runs again and generates an
 			 * emulation fault to activate the FPU.
 			 */
-			if(p->fpsave.addr != nil)
-				fpsave(&p->fpsave);
+			fpsave(&p->fpsave);
 		}
 		p->fpstate = FPinactive;
 	}
--- /sys/src/9/pc/mem.h	Thu Apr 12 12:25:06 2012
+++ /sys/src/9/pc/mem.h	Tue Apr 24 19:46:07 2012
@@ -20,6 +20,7 @@
 #define	PGROUND(s)	ROUND(s, BY2PG)
 #define CACHELINESZ	32			/* pentium & later */
 #define	BLOCKALIGN	8
+#define FPalign		16			/* required for FXSAVE */
 
 /*
  * In 32-bit mode, the MAXMACH limit is 32 without
--- /sys/src/9/port/portdat.h	Thu Apr 19 15:29:43 2012
+++ /sys/src/9/port/portdat.h	Tue Apr 24 19:46:07 2012
@@ -707,7 +707,6 @@
 	void	*kparg;
 
 	FPsave	fpsave;		/* address of this is known by db */
-	void	(*fpexit)(void); /* if non-nil, called by pexit */
 	int	scallnr;	/* sys call number - known by db */
 	Sargs	s;		/* address of this is known by db */
 	int	nerrlab;
--- /sys/src/9/port/proc.c	Thu Apr 19 15:29:43 2012
+++ /sys/src/9/port/proc.c	Tue Apr 24 19:46:07 2012
@@ -1047,9 +1047,6 @@
 
 	if(up->syscalltrace)
 		free(up->syscalltrace);
-	up->fpstate = FPinit;
-	if(up->fpexit)
-		up->fpexit();
 	up->alarm = 0;
 	if (up->tt)
 		timerdel(up);