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ARM: 6407/1: mmu: Setup MT_MEMORY and MT_MEMORY_NONCACHED L1 entries
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This patch populates the L1 entries for MT_MEMORY and MT_MEMORY_NONCACHED
types so that at boot-up, we can map memories outside system memory
at page level granularity

Previously the mapping was limiting to section level, which creates
unnecessary additional mapping for which physical memory may not
present. On the newer ARM with speculation, this is dangerous and can
result in untraceable aborts.

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Santosh Shilimkar authored and Russell King committed Sep 25, 2010
1 parent f933b87 commit f1a2481
Showing 1 changed file with 15 additions and 2 deletions.
17 changes: 15 additions & 2 deletions arch/arm/mm/mmu.c
Original file line number Diff line number Diff line change
Expand Up @@ -247,6 +247,9 @@ static struct mem_type mem_types[] = {
.domain = DOMAIN_USER,
},
[MT_MEMORY] = {
.prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
L_PTE_USER | L_PTE_EXEC,
.prot_l1 = PMD_TYPE_TABLE,
.prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE,
.domain = DOMAIN_KERNEL,
},
Expand All @@ -255,6 +258,9 @@ static struct mem_type mem_types[] = {
.domain = DOMAIN_KERNEL,
},
[MT_MEMORY_NONCACHED] = {
.prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
L_PTE_USER | L_PTE_EXEC | L_PTE_MT_BUFFERABLE,
.prot_l1 = PMD_TYPE_TABLE,
.prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE,
.domain = DOMAIN_KERNEL,
},
Expand Down Expand Up @@ -412,9 +418,12 @@ static void __init build_mem_type_table(void)
* Enable CPU-specific coherency if supported.
* (Only available on XSC3 at the moment.)
*/
if (arch_is_coherent() && cpu_is_xsc3())
if (arch_is_coherent() && cpu_is_xsc3()) {
mem_types[MT_MEMORY].prot_sect |= PMD_SECT_S;

mem_types[MT_MEMORY].prot_pte |= L_PTE_SHARED;
mem_types[MT_MEMORY_NONCACHED].prot_sect |= PMD_SECT_S;
mem_types[MT_MEMORY_NONCACHED].prot_pte |= L_PTE_SHARED;
}
/*
* ARMv6 and above have extended page tables.
*/
Expand All @@ -439,7 +448,9 @@ static void __init build_mem_type_table(void)
mem_types[MT_DEVICE_CACHED].prot_sect |= PMD_SECT_S;
mem_types[MT_DEVICE_CACHED].prot_pte |= L_PTE_SHARED;
mem_types[MT_MEMORY].prot_sect |= PMD_SECT_S;
mem_types[MT_MEMORY].prot_pte |= L_PTE_SHARED;
mem_types[MT_MEMORY_NONCACHED].prot_sect |= PMD_SECT_S;
mem_types[MT_MEMORY_NONCACHED].prot_pte |= L_PTE_SHARED;
#endif
}

Expand Down Expand Up @@ -476,6 +487,8 @@ static void __init build_mem_type_table(void)
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_MEMORY].prot_pte |= kern_pgprot;
mem_types[MT_MEMORY_NONCACHED].prot_sect |= ecc_mask;
mem_types[MT_ROM].prot_sect |= cp->pmd;

switch (cp->pmd) {
Expand Down

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