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

Luck, Tony
2003-05-28T20:05:56Z

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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.
*/