[PATCH V6] ARM: LPAE: Fix mapping in alloc_init_section for unaligned addresses
Sricharan R
r.sricharan at ti.com
Mon Mar 18 01:50:47 EDT 2013
Hi Russell,
On Monday 18 March 2013 01:22 AM, Christoffer Dall wrote:
> On Sat, Mar 16, 2013 at 10:05 PM, Sricharan R <r.sricharan at ti.com> wrote:
>> 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
>>
> Acked-by: Christoffer Dall <chris at cloudcar.com>
I am not able to add this in to the patch system because my login fails.
I was trying using the credentials registered with linux-arm-kernel
mailing list. Can you please help me here ?
Regards,
Sricharan
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