[ARM SMP] Add support for shared memory attribute
We need to set the shared memory attribute in the page tables
on SMP systems to allow the cache coherency to operate.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mm/mm-armv.c b/arch/arm/mm/mm-armv.c
index fb5b402..9e50127 100644
--- a/arch/arm/mm/mm-armv.c
+++ b/arch/arm/mm/mm-armv.c
@@ -354,7 +354,7 @@
{
struct cachepolicy *cp;
unsigned int cr = get_cr();
- unsigned int user_pgprot;
+ unsigned int user_pgprot, kern_pgprot;
int cpu_arch = cpu_architecture();
int i;
@@ -381,7 +381,7 @@
}
cp = &cache_policies[cachepolicy];
- user_pgprot = cp->pte;
+ kern_pgprot = user_pgprot = cp->pte;
/*
* ARMv6 and above have extended page tables.
@@ -393,6 +393,7 @@
*/
mem_types[MT_MEMORY].prot_sect &= ~PMD_BIT4;
mem_types[MT_ROM].prot_sect &= ~PMD_BIT4;
+
/*
* Mark cache clean areas and XIP ROM read only
* from SVC mode and no access from userspace.
@@ -412,32 +413,47 @@
* (iow, non-global)
*/
user_pgprot |= L_PTE_ASID;
+
+#ifdef CONFIG_SMP
+ /*
+ * Mark memory with the "shared" attribute for SMP systems
+ */
+ user_pgprot |= L_PTE_SHARED;
+ kern_pgprot |= L_PTE_SHARED;
+ mem_types[MT_MEMORY].prot_sect |= PMD_SECT_S;
+#endif
}
+ for (i = 0; i < 16; i++) {
+ unsigned long v = pgprot_val(protection_map[i]);
+ v = (v & ~(L_PTE_BUFFERABLE|L_PTE_CACHEABLE)) | user_pgprot;
+ protection_map[i] = __pgprot(v);
+ }
+
+ mem_types[MT_LOW_VECTORS].prot_pte |= kern_pgprot;
+ mem_types[MT_HIGH_VECTORS].prot_pte |= kern_pgprot;
+
if (cpu_arch >= CPU_ARCH_ARMv5) {
- mem_types[MT_LOW_VECTORS].prot_pte |= cp->pte & PTE_CACHEABLE;
- mem_types[MT_HIGH_VECTORS].prot_pte |= cp->pte & PTE_CACHEABLE;
+#ifndef CONFIG_SMP
+ /*
+ * Only use write-through for non-SMP systems
+ */
+ mem_types[MT_LOW_VECTORS].prot_pte &= ~L_PTE_BUFFERABLE;
+ mem_types[MT_HIGH_VECTORS].prot_pte &= ~L_PTE_BUFFERABLE;
+#endif
} else {
- mem_types[MT_LOW_VECTORS].prot_pte |= cp->pte;
- mem_types[MT_HIGH_VECTORS].prot_pte |= cp->pte;
mem_types[MT_MINICLEAN].prot_sect &= ~PMD_SECT_TEX(1);
}
+ pgprot_kernel = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG |
+ L_PTE_DIRTY | L_PTE_WRITE |
+ L_PTE_EXEC | kern_pgprot);
+
mem_types[MT_LOW_VECTORS].prot_l1 |= ecc_mask;
mem_types[MT_HIGH_VECTORS].prot_l1 |= ecc_mask;
mem_types[MT_MEMORY].prot_sect |= ecc_mask | cp->pmd;
mem_types[MT_ROM].prot_sect |= cp->pmd;
- for (i = 0; i < 16; i++) {
- unsigned long v = pgprot_val(protection_map[i]);
- v = (v & ~(PTE_BUFFERABLE|PTE_CACHEABLE)) | user_pgprot;
- protection_map[i] = __pgprot(v);
- }
-
- pgprot_kernel = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG |
- L_PTE_DIRTY | L_PTE_WRITE |
- L_PTE_EXEC | cp->pte);
-
switch (cp->pmd) {
case PMD_SECT_WT:
mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_WT;
diff --git a/arch/arm/mm/proc-v6.S b/arch/arm/mm/proc-v6.S
index 9bb5fff..a39d8fa 100644
--- a/arch/arm/mm/proc-v6.S
+++ b/arch/arm/mm/proc-v6.S
@@ -112,6 +112,9 @@
ENTRY(cpu_v6_switch_mm)
mov r2, #0
ldr r1, [r1, #MM_CONTEXT_ID] @ get mm->context.id
+#ifdef CONFIG_SMP
+ orr r0, r0, #2 @ set shared pgtable
+#endif
mcr p15, 0, r2, c7, c5, 6 @ flush BTAC/BTB
mcr p15, 0, r2, c7, c10, 4 @ drain write buffer
mcr p15, 0, r0, c2, c0, 0 @ set TTB 0
@@ -140,7 +143,7 @@
ENTRY(cpu_v6_set_pte)
str r1, [r0], #-2048 @ linux version
- bic r2, r1, #0x000007f0
+ bic r2, r1, #0x000003f0
bic r2, r2, #0x00000003
orr r2, r2, #PTE_EXT_AP0 | 2
@@ -198,6 +201,9 @@
mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
mcr p15, 0, r0, c8, c7, 0 @ invalidate I + D TLBs
mcr p15, 0, r0, c2, c0, 2 @ TTB control register
+#ifdef CONFIG_SMP
+ orr r4, r4, #2 @ set shared pgtable
+#endif
mcr p15, 0, r4, c2, c0, 1 @ load TTB1
#ifdef CONFIG_VFP
mrc p15, 0, r0, c1, c0, 2