From: r.sricharan@ti•com (R Sricharan)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH V5] ARM: LPAE: Fix mapping in alloc_init_section for unaligned addresses
Date: Mon, 11 Feb 2013 14:40:19 +0530 [thread overview]
Message-ID: <5118B57B.2050105@ti.com> (raw)
In-Reply-To: <CANOGCgMEdae53GGGNxU6eHqrNLOhZ1wUyXfADEooLkmZ3bC7Og@mail.gmail.com>
On Friday 08 February 2013 08:13 PM, Christoffer Dall wrote:
> On Fri, Feb 8, 2013 at 6:30 AM, R Sricharan <r.sricharan@ti•com> wrote:
>> 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@ti•com>
>> Cc: Catalin Marinas <catalin.marinas@arm•com>
>> Cc: Christoffer Dall <chris@cloudcar•com>
>> Cc: Russell King <linux@arm•linux.org.uk>
>> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti•com>
>> Tested-by: Christoffer Dall <chris@cloudcar•com>
>
> I don't think that I've tested this version of the patch, but ok.
>
>> ---
>> [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.
>>
>> arch/arm/mm/mmu.c | 66 ++++++++++++++++++++++++++++++++---------------------
>> 1 file changed, 40 insertions(+), 26 deletions(-)
>>
>> diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
>> index ce328c7..a89df2b 100644
>> --- a/arch/arm/mm/mmu.c
>> +++ b/arch/arm/mm/mmu.c
>> @@ -576,39 +576,53 @@ 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,
>> +static void __init map_init_section(pmd_t *pmd, unsigned long addr,
>> + unsigned long end, phys_addr_t phys,
>> + const struct mem_type *type)
>> +{
>> +#ifndef CONFIG_ARM_LPAE
>> + if (addr & SECTION_SIZE)
>> + pmd++;
>> +#endif
>
> I still think this one deserves a comment.
Ok, added it in updated version. In fact i was getting
little verbose in describing this, but not sure if there
is much simpler way.
>
>> + do {
>> + *pmd = __pmd(phys | type->prot_sect);
>> + phys += SECTION_SIZE;
>> + } while (pmd++, addr += SECTION_SIZE, addr != end);
>> +
>> + flush_pmd_entry(pmd);
>> +}
>> +
>> +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;
>>
>> - /*
>> - * 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.
>> - */
>> - if (type->prot_sect && ((addr | end | phys) & ~SECTION_MASK) == 0) {
>> - pmd_t *p = pmd;
>> -
>> -#ifndef CONFIG_ARM_LPAE
>> - if (addr & SECTION_SIZE)
>> - pmd++;
>> -#endif
>> -
>> - do {
>> - *pmd = __pmd(phys | type->prot_sect);
>> - phys += SECTION_SIZE;
>> - } while (pmd++, addr += SECTION_SIZE, addr != end);
>> + do {
>> + /*
>> + * With LPAE, we may be required to loop in, to map
>
> nit: "loop in" should just be loop. Also, I would not say that we may
> be required to loop in the LPAE case, but that for LPAE we must loop
> over all the PMDs for the given range.
ok. correct.
>
>> + * all the pmds for the given range.
>> + */
>> + next = pmd_addr_end(addr, end);
>>
>> - flush_pmd_entry(p);
>> - } else {
>> /*
>> - * No need to loop; pte's aren't interested in the
>> - * individual L1 entries.
>> + * 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.
>
> This is not true for LPAE, so now when we're changing the comment, we
> should be more specific.
yes, probably the second line of the comment is not common.
i am using it to describe this block now.
#ifndef CONFIG_ARM_LPAE
if (addr & SECTION_SIZE)
pmd++;
#endif
Regards,
Sricharan
next prev parent reply other threads:[~2013-02-11 9:10 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-08 11:30 [PATCH V5] ARM: LPAE: Fix mapping in alloc_init_section for unaligned addresses R Sricharan
2013-02-08 14:43 ` Christoffer Dall
2013-02-08 14:49 ` Santosh Shilimkar
2013-02-11 9:09 ` R Sricharan
2013-02-11 9:10 ` R Sricharan [this message]
2013-02-08 15:21 ` Catalin Marinas
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