[IA64-SGI] - New SN hardware support - ptc_fixes

Shub2 provides a much improved mechanism for issuing internode
TLB purges. Add code to support the newer mechanism. There is also 
some debug code (disabled) that is useful for testing.

Collect statistics on the number, type & duration of TLB purges.
This data will be useful for making future improvements in the algorithms.

Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

arch/ia64/sn/kernel/setup.c

@@ -403,6 +403,7 @@ static void __init sn_init_pdas(char **cmdline_p)
 		memset(nodepdaindr[cnode], 0, sizeof(nodepda_t));
 		memset(nodepdaindr[cnode]->phys_cpuid, -1,
 		    sizeof(nodepdaindr[cnode]->phys_cpuid));
+		spin_lock_init(&nodepdaindr[cnode]->ptc_lock);
 	}
 
 	/*

arch/ia64/sn/kernel/sn2/ptc_deadlock.S

@@ -3,15 +3,15 @@
  * License.  See the file "COPYING" in the main directory of this archive
  * for more details.
  *
- * Copyright (C) 2000-2004 Silicon Graphics, Inc. All rights reserved.
+ * Copyright (C) 2000-2005 Silicon Graphics, Inc. All rights reserved.
  */
 
 #include <asm/types.h>
 #include <asm/sn/shub_mmr.h>
 
 #define DEADLOCKBIT	SH_PIO_WRITE_STATUS_WRITE_DEADLOCK_SHFT
 #define WRITECOUNTMASK	SH_PIO_WRITE_STATUS_PENDING_WRITE_COUNT_MASK
-#define ALIAS_OFFSET	(SH1_PIO_WRITE_STATUS_0_ALIAS-SH1_PIO_WRITE_STATUS_0)
+#define ALIAS_OFFSET	8
 
 
 	.global	sn2_ptc_deadlock_recovery_core
@@ -36,13 +36,15 @@ sn2_ptc_deadlock_recovery_core:
 	extr.u	piowcphy=piowc,0,61;;	// Convert piowc to uncached physical address
 	dep	piowcphy=-1,piowcphy,63,1
 	movl	mask=WRITECOUNTMASK
+	mov	r8=r0
 
 1:
 	add	scr2=ALIAS_OFFSET,piowc	// Address of WRITE_STATUS alias register 
-	mov	scr1=7;;		// Clear DEADLOCK, WRITE_ERROR, MULTI_WRITE_ERROR
-	st8.rel	[scr2]=scr1;;
+	;;
+	ld8.acq	scr1=[scr2];;
 
 5:	ld8.acq	scr1=[piowc];;		// Wait for PIOs to complete.
+	hint	@pause
 	and	scr2=scr1,mask;;	// mask of writecount bits
 	cmp.ne	p6,p0=zeroval,scr2
 (p6)	br.cond.sptk 5b
@@ -57,6 +59,7 @@ sn2_ptc_deadlock_recovery_core:
 	st8.rel [ptc0]=data0		// Write PTC0 & wait for completion.
 
 5:	ld8.acq	scr1=[piowcphy];;	// Wait for PIOs to complete.
+	hint	@pause
 	and	scr2=scr1,mask;;	// mask of writecount bits
 	cmp.ne	p6,p0=zeroval,scr2
 (p6)	br.cond.sptk 5b;;
@@ -67,6 +70,7 @@ sn2_ptc_deadlock_recovery_core:
 (p7)	st8.rel [ptc1]=data1;;		// Now write PTC1.
 
 5:	ld8.acq	scr1=[piowcphy];;	// Wait for PIOs to complete.
+	hint	@pause
 	and	scr2=scr1,mask;;	// mask of writecount bits
 	cmp.ne	p6,p0=zeroval,scr2
 (p6)	br.cond.sptk 5b
@@ -77,6 +81,7 @@ sn2_ptc_deadlock_recovery_core:
 	srlz.i;;
 	////////////// END   PHYSICAL MODE ////////////////////
 
+(p8)	add	r8=1,r8
 (p8)	br.cond.spnt 1b;;		// Repeat if DEADLOCK occurred.
 
 	br.ret.sptk	rp