RE: [Linux-ia64] RE: [PATCH] head.S fix for unusual load addrs

["Luck, Tony" <tony.luck@intel.com>]

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Patch in previous post is incomplete ... here's the
full version.

-Tony

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diff -ru l2569-mosberger/arch/ia64/kernel/ivt.S l2569-reloc/arch/ia64/kernel/ivt.S
--- l2569-mosberger/arch/ia64/kernel/ivt.S	Mon May 19 09:40:04 2003
+++ l2569-reloc/arch/ia64/kernel/ivt.S	Wed May 28 09:37:02 2003
@@ -122,12 +122,9 @@
 	shr.u r18=r22,PGDIR_SHIFT		// get bits 33-63 of the faulting address
 	;;
 (p7)	dep r17=r17,r19,(PAGE_SHIFT-3),3	// put region number bits in place
-	.global ia64_ivt_patch1
-ia64_ivt_patch1:
-{	.mlx // we patch this bundle to include physical address of swapper_pg_dir
-	srlz.d					// ensure "rsm psr.dt" has taken effect
-(p6)	movl r19=swapper_pg_dir			// region 5 is rooted at swapper_pg_dir
-}
+
+	LOAD_PHYSICAL(srlz.d, p6, r19, swapper_pg_dir)	// region 5 is rooted at swapper_pg_dir
+
 	.pred.rel "mutex", p6, p7
 (p6)	shr.u r21=r21,PGDIR_SHIFT+PAGE_SHIFT
 (p7)	shr.u r21=r21,PGDIR_SHIFT+PAGE_SHIFT-3
@@ -420,12 +417,9 @@
 	shr.u r18=r16,PGDIR_SHIFT		// get bits 33-63 of faulting address
 	;;
 (p7)	dep r17=r17,r19,(PAGE_SHIFT-3),3	// put region number bits in place
-	.global ia64_ivt_patch2
-ia64_ivt_patch2:
-{	.mlx // we patch this bundle to include physical address of swapper_pg_dir
-	srlz.d					// ensure "rsm psr.dt" has taken effect
-(p6)	movl r19=swapper_pg_dir			// region 5 is rooted at swapper_pg_dir
-}
+
+	LOAD_PHYSICAL(srlz.d, p6, r19, swapper_pg_dir)	// region 5 is rooted at swapper_pg_dir
+
 	.pred.rel "mutex", p6, p7
 (p6)	shr.u r21=r21,PGDIR_SHIFT+PAGE_SHIFT
 (p7)	shr.u r21=r21,PGDIR_SHIFT+PAGE_SHIFT-3
diff -ru l2569-mosberger/arch/ia64/kernel/setup.c l2569-reloc/arch/ia64/kernel/setup.c
--- l2569-mosberger/arch/ia64/kernel/setup.c	Wed May 28 13:03:29 2003
+++ l2569-reloc/arch/ia64/kernel/setup.c	Wed May 28 12:02:43 2003
@@ -348,43 +348,51 @@
 }
 
 /*
- * There are two places in the performance critical path of
- * the exception handling code where we need to know the physical
- * address of the swapper_pg_dir structure.  This routine
- * patches the "movl" instructions to load the value needed.
+ * We need sometimes to load the physical address of a kernel
+ * object.  Often we can convert the virtual address to physical
+ * at execution time, but sometimes (either for performance reasons
+ * or during error recovery) we cannot to this.  Patch the marked
+ * bundles to load the physical address.
+ * The 64-bit value in a "movl reg=value" is scattered between the
+ * two words of the bundle like this:
+ *
+ * 6  6         5         4         3         2         1
+ * 3210987654321098765432109876543210987654321098765432109876543210
+ * ABBBBBBBBBBBBBBBBBBBBBBBCCCCCCCCCCCCCCCCCCDEEEEEFFFFFFFFFGGGGGGG
+ *
+ * CCCCCCCCCCCCCCCCCCxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
+ * xxxxAFFFFFFFFFEEEEEDxGGGGGGGxxxxxxxxxxxxxBBBBBBBBBBBBBBBBBBBBBBB
  */
 static void __init
-patch_ivt_with_phys_swapper_pg_dir(void)
+patch_physical(void)
 {
-	extern char ia64_ivt_patch1[], ia64_ivt_patch2[];
-	unsigned long spd = ia64_tpa((__u64)swapper_pg_dir);
-	unsigned long *p;
-
-	p = (unsigned long *)ia64_imva(ia64_ivt_patch1);
-
-	*p = (*p & 0x3fffffffffffUL) |
-		((spd & 0x000000ffffc00000UL)<<24);
-	p++;
-	*p = (*p & 0xf000080fff800000UL) |
-		((spd & 0x8000000000000000UL) >> 4)  |
-		((spd & 0x7fffff0000000000UL) >> 40) |
-		((spd & 0x00000000001f0000UL) << 29) |
-		((spd & 0x0000000000200000UL) << 23) |
-		((spd & 0x000000000000ff80UL) << 43) |
-		((spd & 0x000000000000007fUL) << 36);
-
-	p = (unsigned long *)ia64_imva(ia64_ivt_patch2);
-
-	*p = (*p & 0x3fffffffffffUL) |
-		((spd & 0x000000ffffc00000UL)<<24);
-	p++;
-	*p = (*p & 0xf000080fff800000UL) |
-		((spd & 0x8000000000000000UL) >> 4)  |
-		((spd & 0x7fffff0000000000UL) >> 40) |
-		((spd & 0x00000000001f0000UL) << 29) |
-		((spd & 0x0000000000200000UL) << 23) |
-		((spd & 0x000000000000ff80UL) << 43) |
-		((spd & 0x000000000000007fUL) << 36);
+	extern unsigned long *__start___vtop_patchlist[], *__end____vtop_patchlist[];
+	unsigned long **e, *p, paddr, vaddr;
+
+	for (e = __start___vtop_patchlist; e < __end____vtop_patchlist; e++) {
+		p = *e;
+
+		vaddr = ((p[1] & 0x0800000000000000UL) << 4)  | /*A*/
+			((p[1] & 0x00000000007fffffUL) << 40) | /*B*/
+			((p[0] & 0xffffc00000000000UL) >> 24) | /*C*/
+			((p[1] & 0x0000100000000000UL) >> 23) | /*D*/
+			((p[1] & 0x0003e00000000000UL) >> 29) | /*E*/
+			((p[1] & 0x07fc000000000000UL) >> 43) | /*F*/
+			((p[1] & 0x000007f000000000UL) >> 36);  /*G*/
+
+		paddr = ia64_tpa(vaddr);
+
+		*p = (*p & 0x3fffffffffffUL) |
+			((paddr & 0x000000ffffc00000UL)<<24);	/*C*/
+		p++;
+		*p = (*p & 0xf000080fff800000UL) |
+			((paddr & 0x8000000000000000UL) >> 4)  | /*A*/
+			((paddr & 0x7fffff0000000000UL) >> 40) | /*B*/
+			((paddr & 0x0000000000200000UL) << 23) | /*D*/
+			((paddr & 0x00000000001f0000UL) << 29) | /*E*/
+			((paddr & 0x000000000000ff80UL) << 43) | /*F*/
+			((paddr & 0x000000000000007fUL) << 36);  /*G*/
+	}
 }
 
 
@@ -396,7 +404,7 @@
 
 	unw_init();
 
-	patch_ivt_with_phys_swapper_pg_dir();
+	patch_physical();
 
 	*cmdline_p = __va(ia64_boot_param->command_line);
 	strncpy(saved_command_line, *cmdline_p, sizeof(saved_command_line));
@@ -779,8 +787,6 @@
 	/* Clear the stack memory reserved for pt_regs: */
 	memset(ia64_task_regs(current), 0, sizeof(struct pt_regs));
 
-	ia64_set_kr(IA64_KR_FPU_OWNER, 0);
-
 	/*
 	 * Initialize default control register to defer all speculative faults.  The
 	 * kernel MUST NOT depend on a particular setting of these bits (in other words,
diff -ru l2569-mosberger/arch/ia64/vmlinux.lds.S l2569-reloc/arch/ia64/vmlinux.lds.S
--- l2569-mosberger/arch/ia64/vmlinux.lds.S	Mon May 19 09:40:03 2003
+++ l2569-reloc/arch/ia64/vmlinux.lds.S	Wed May 28 09:52:44 2003
@@ -55,6 +55,13 @@
 	  __stop___ex_table = .;
 	}
 
+  __vtop_patchlist : AT(ADDR(__vtop_patchlist) - LOAD_OFFSET)
+	{
+	  __start___vtop_patchlist = .;
+	  *(__vtop_patchlist)
+	  __end____vtop_patchlist = .;
+	}
+
   __mckinley_e9_bundles : AT(ADDR(__mckinley_e9_bundles) - LOAD_OFFSET)
 	{
 	  __start___mckinley_e9_bundles = .;
diff -ru l2569-mosberger/include/asm-ia64/asmmacro.h l2569-reloc/include/asm-ia64/asmmacro.h
--- l2569-mosberger/include/asm-ia64/asmmacro.h	Mon May 19 09:41:01 2003
+++ l2569-reloc/include/asm-ia64/asmmacro.h	Wed May 28 09:48:20 2003
@@ -51,6 +51,22 @@
   [99:]	x
 
 /*
+ * Mark instructions that need a load of a virtual address patched to be
+ * a load of a physical address.  We use this either in critical performance
+ * path (ivt.S - TLB miss processing) or in places where it might not be
+ * safe to use a "tpa" instruction (mca_asm.S - error recovery).
+ */
+	.section "__vtop_patchlist", "a"	// declare section & section attributes
+	.previous
+
+#define	LOAD_PHYSICAL(op, preg, reg, obj)	\
+1: {	.mlx;					\
+	op;					\
+(preg)	movl reg = obj;				\
+   };						\
+	.xdata8 "__vtop_patchlist", 1b
+
+/*
  * For now, we always put in the McKinley E9 workaround.  On CPUs that don't need it,
  * we'll patch out the work-around bundles with NOPs, so their impact is minimal.
  */