From: R Sricharan <r.sricharan at ti.com>
With LPAE enabled, alloc_init_section() does not map the entire
address space for unaligned addresses.
The issue also reproduced with CMA + LPAE. CMA tries to map 16MB
with page granularity mappings during boot. alloc_init_pte()
is called and out of 16MB, only 2MB gets mapped and rest remains
unaccessible.
Because of this OMAP5 boot is broken with CMA + LPAE enabled.
Fix the issue by ensuring that the entire addresses are
mapped.
Signed-off-by: R Sricharan <r.sricharan at ti.com>
Cc: Catalin Marinas <catalin.marinas at arm.com>
Cc: Christoffer Dall <chris at cloudcar.com>
Cc: Russell King <linux at arm.linux.org.uk>
Cc: Santosh Shilimkar <santosh.shilimkar at ti.com>
Tested-by: Laura Abbott <lauraa at codeaurora.org>
Acked-by: Catalin Marinas <catalin.marinas at arm.com>
---
[V2] Moved the loop to alloc_init_pte as per Russell's
feedback and changed the subject accordingly.
Using PMD_XXX instead of SECTION_XXX to avoid
different loop increments with/without LPAE.
[v3] Removed the dummy variable phys and updated
the commit log for CMA case.
[v4] Resending with updated change log and
updating the tags.
[v5] Renamed alloc_init_section to alloc_init_pmd
and moved the loop back there. Also introduced
map_init_section as per Catalin's comments.
[v6] Corrected tags and updated the comments for code.
arch/arm/mm/mmu.c | 73 ++++++++++++++++++++++++++++++++++-------------------
1 file changed, 47 insertions(+), 26 deletions(-)
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index e95a996..7897894 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -598,39 +598,60 @@ static void __init alloc_init_pte(pmd_t *pmd, unsigned long addr,
} while (pte++, addr += PAGE_SIZE, addr != end);
}
-static void __init alloc_init_section(pud_t *pud, unsigned long addr,
- unsigned long end, phys_addr_t phys,
- const struct mem_type *type)
+static void __init map_init_section(pmd_t *pmd, unsigned long addr,
+ unsigned long end, phys_addr_t phys,
+ const struct mem_type *type)
{
- pmd_t *pmd = pmd_offset(pud, addr);
-
+#ifndef CONFIG_ARM_LPAE
/*
- * Try a section mapping - end, addr and phys must all be aligned
- * to a section boundary. Note that PMDs refer to the individual
- * L1 entries, whereas PGDs refer to a group of L1 entries making
- * up one logical pointer to an L2 table.
+ * In classic MMU format, puds and pmds are folded in to
+ * the pgds. pmd_offset gives the PGD entry. PGDs refer to a
+ * group of L1 entries making up one logical pointer to
+ * an L2 table (2MB), where as PMDs refer to the individual
+ * L1 entries (1MB). Hence increment to get the correct
+ * offset for odd 1MB sections.
+ * (See arch/arm/include/asm/pgtable-2level.h)
*/
- if (type->prot_sect && ((addr | end | phys) & ~SECTION_MASK) == 0) {
- pmd_t *p = pmd;
-
-#ifndef CONFIG_ARM_LPAE
- if (addr & SECTION_SIZE)
- pmd++;
+ if (addr & SECTION_SIZE)
+ pmd++;
#endif
+ do {
+ *pmd = __pmd(phys | type->prot_sect);
+ phys += SECTION_SIZE;
+ } while (pmd++, addr += SECTION_SIZE, addr != end);
- do {
- *pmd = __pmd(phys | type->prot_sect);
- phys += SECTION_SIZE;
- } while (pmd++, addr += SECTION_SIZE, addr != end);
+ flush_pmd_entry(pmd);
+}
- flush_pmd_entry(p);
- } else {
+static void __init alloc_init_pmd(pud_t *pud, unsigned long addr,
+ unsigned long end, phys_addr_t phys,
+ const struct mem_type *type)
+{
+ pmd_t *pmd = pmd_offset(pud, addr);
+ unsigned long next;
+
+ do {
/*
- * No need to loop; pte's aren't interested in the
- * individual L1 entries.
+ * With LPAE, we must loop over to map
+ * all the pmds for the given range.
*/
- alloc_init_pte(pmd, addr, end, __phys_to_pfn(phys), type);
- }
+ next = pmd_addr_end(addr, end);
+
+ /*
+ * Try a section mapping - addr, next and phys must all be
+ * aligned to a section boundary.
+ */
+ if (type->prot_sect &&
+ ((addr | next | phys) & ~SECTION_MASK) == 0) {
+ map_init_section(pmd, addr, next, phys, type);
+ } else {
+ alloc_init_pte(pmd, addr, next,
+ __phys_to_pfn(phys), type);
+ }
+
+ phys += next - addr;
+
+ } while (pmd++, addr = next, addr != end);
}
static void __init alloc_init_pud(pgd_t *pgd, unsigned long addr,
@@ -641,7 +662,7 @@ static void __init alloc_init_pud(pgd_t *pgd, unsigned long addr,
do {
next = pud_addr_end(addr, end);
- alloc_init_section(pud, addr, next, phys, type);
+ alloc_init_pmd(pud, addr, next, phys, type);
phys += next - addr;
} while (pud++, addr = next, addr != end);
}
--
1.7.9.5