From 6626a7076d39f0a18156cdd97d4e2cbef91ad701 Mon Sep 17 00:00:00 2001
From: Russell King <rmk@dyn-67.arm.linux.org.uk>
Date: Wed, 10 Aug 2005 16:18:35 +0100
Subject: [PATCH] [ARM] Control v6 'global' bit via Linux PTE entries
Unfortunately, we can't use the "user" bit in the page tables to
control whether a page table entry is "global" or "asid" specific,
since the vector page is mapped as "user" accessible but is not
process specific.
Therefore, give direct control of the ARMv6 "nG" (not global)
bit to the mm layers.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
arch/arm/mm/mm-armv.c | 17 ++++++++++++++---
arch/arm/mm/proc-v6.S | 4 ++--
include/asm-arm/pgtable.h | 2 ++
3 files changed, 18 insertions(+), 5 deletions(-)
diff --git a/arch/arm/mm/mm-armv.c b/arch/arm/mm/mm-armv.c
index e33fe4229d05..3c655c54e231 100644
--- a/arch/arm/mm/mm-armv.c
+++ b/arch/arm/mm/mm-armv.c
@@ -383,6 +383,7 @@ static void __init build_mem_type_table(void)
{
struct cachepolicy *cp;
unsigned int cr = get_cr();
+ unsigned int user_pgprot;
int cpu_arch = cpu_architecture();
int i;
@@ -408,6 +409,9 @@ static void __init build_mem_type_table(void)
}
}
+ cp = &cache_policies[cachepolicy];
+ user_pgprot = cp->pte;
+
/*
* ARMv6 and above have extended page tables.
*/
@@ -426,11 +430,18 @@ static void __init build_mem_type_table(void)
mem_types[MT_MINICLEAN].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
+ /*
+ * Mark the device area as "shared device"
+ */
mem_types[MT_DEVICE].prot_pte |= L_PTE_BUFFERABLE;
mem_types[MT_DEVICE].prot_sect |= PMD_SECT_BUFFERED;
- }
- cp = &cache_policies[cachepolicy];
+ /*
+ * User pages need to be mapped with the ASID
+ * (iow, non-global)
+ */
+ user_pgprot |= L_PTE_ASID;
+ }
if (cpu_arch >= CPU_ARCH_ARMv5) {
mem_types[MT_LOW_VECTORS].prot_pte |= cp->pte & PTE_CACHEABLE;
@@ -448,7 +459,7 @@ static void __init build_mem_type_table(void)
for (i = 0; i < 16; i++) {
unsigned long v = pgprot_val(protection_map[i]);
- v &= (~(PTE_BUFFERABLE|PTE_CACHEABLE)) | cp->pte;
+ v &= (~(PTE_BUFFERABLE|PTE_CACHEABLE)) | user_pgprot;
protection_map[i] = __pgprot(v);
}
diff --git a/arch/arm/mm/proc-v6.S b/arch/arm/mm/proc-v6.S
index 75e65522c8d2..3429ddcf65d1 100644
--- a/arch/arm/mm/proc-v6.S
+++ b/arch/arm/mm/proc-v6.S
@@ -133,7 +133,7 @@ ENTRY(cpu_v6_switch_mm)
ENTRY(cpu_v6_set_pte)
str r1, [r0], #-2048 @ linux version
- bic r2, r1, #0x00000ff0
+ bic r2, r1, #0x000007f0
bic r2, r2, #0x00000003
orr r2, r2, #PTE_EXT_AP0 | 2
@@ -142,7 +142,7 @@ ENTRY(cpu_v6_set_pte)
orreq r2, r2, #PTE_EXT_APX
tst r1, #L_PTE_USER
- orrne r2, r2, #PTE_EXT_AP1 | PTE_EXT_NG
+ orrne r2, r2, #PTE_EXT_AP1
tstne r2, #PTE_EXT_APX
bicne r2, r2, #PTE_EXT_APX | PTE_EXT_AP0
diff --git a/include/asm-arm/pgtable.h b/include/asm-arm/pgtable.h
index 8bd4c0faf230..478c49b56e18 100644
--- a/include/asm-arm/pgtable.h
+++ b/include/asm-arm/pgtable.h
@@ -230,6 +230,8 @@ extern void __pgd_error(const char *file, int line, unsigned long val);
#define L_PTE_WRITE (1 << 5)
#define L_PTE_EXEC (1 << 6)
#define L_PTE_DIRTY (1 << 7)
+#define L_PTE_SHARED (1 << 10) /* shared between CPUs (v6) */
+#define L_PTE_ASID (1 << 11) /* non-global (use ASID, v6) */
#ifndef __ASSEMBLY__
--
2.34.1