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ARM: ensure C page table setup code follows assembly code (part II)

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This does the same as the previous commit, but for the S bit, which also
needs to match the initial value which the assembly code used for the
same reasons.  Again, we add a check for SMP to ensure that the page
tables are correctly setup for SMP.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Russell King 2014-06-02 09:29:37 +01:00
parent ca8f0b0a54
commit 20e7e36433
1 changed files with 19 additions and 8 deletions
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27
arch/arm/mm/mmu.c
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@ -117,6 +117,8 @@ static struct cachepolicy cache_policies[] __initdata = {
};
#ifdef CONFIG_CPU_CP15
static unsigned long initial_pmd_value __initdata = 0;
/*
* Initialise the cache_policy variable with the initial state specified
* via the "pmd" value. This is used to ensure that on ARMv6 and later,
@ -128,6 +130,8 @@ void __init init_default_cache_policy(unsigned long pmd)
{
int i;
initial_pmd_value = pmd;
pmd &= PMD_SECT_TEX(1) | PMD_SECT_BUFFERABLE | PMD_SECT_CACHEABLE;
for (i = 0; i < ARRAY_SIZE(cache_policies); i++)
@ -414,9 +418,15 @@ static void __init build_mem_type_table(void)
ecc_mask = 0;
}
if (is_smp() && cachepolicy != CPOLICY_WRITEALLOC) {
pr_warn("Forcing write-allocate cache policy for SMP\n");
cachepolicy = CPOLICY_WRITEALLOC;
if (is_smp()) {
if (cachepolicy != CPOLICY_WRITEALLOC) {
pr_warn("Forcing write-allocate cache policy for SMP\n");
cachepolicy = CPOLICY_WRITEALLOC;
}
if (!(initial_pmd_value & PMD_SECT_S)) {
pr_warn("Forcing shared mappings for SMP\n");
initial_pmd_value |= PMD_SECT_S;
}
}
/*
@ -541,11 +551,12 @@ static void __init build_mem_type_table(void)
mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
#endif
if (is_smp()) {
/*
* Mark memory with the "shared" attribute
* for SMP systems
*/
/*
* If the initial page tables were created with the S bit
* set, then we need to do the same here for the same
* reasons given in early_cachepolicy().
*/
if (initial_pmd_value & PMD_SECT_S) {
user_pgprot |= L_PTE_SHARED;
kern_pgprot |= L_PTE_SHARED;
vecs_pgprot |= L_PTE_SHARED;