From mboxrd@z Thu Jan 1 00:00:00 1970 From: r.sricharan@ti.com (Sricharan R) Date: Mon, 18 Mar 2013 16:24:16 +0530 Subject: [PATCH V6] ARM: LPAE: Fix mapping in alloc_init_section for unaligned addresses In-Reply-To: <20130318104542.GF4977@n2100.arm.linux.org.uk> References: <1363496741-3427-1-git-send-email-r.sricharan@ti.com> <5146AB37.9060307@ti.com> <20130318104542.GF4977@n2100.arm.linux.org.uk> Message-ID: <5146F258.2010905@ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Russell, On Monday 18 March 2013 04:15 PM, Russell King - ARM Linux wrote: > On Mon, Mar 18, 2013 at 11:20:47AM +0530, Sricharan R wrote: >> Hi Russell, >> >> On Monday 18 March 2013 01:22 AM, Christoffer Dall wrote: >>> On Sat, Mar 16, 2013 at 10:05 PM, Sricharan R wrote: >>>> From: R Sricharan >>>> >>>> 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 >>>> Cc: Catalin Marinas >>>> Cc: Christoffer Dall >>>> Cc: Russell King >>>> Cc: Santosh Shilimkar >>>> Tested-by: Laura Abbott >>>> Acked-by: Catalin Marinas >>>> --- >>>> [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 >> >> 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 ? > > The mailing list and my site are two entirely separate and independent > sites. In fact now, the mailing list is hosted by a separate > individual. ok, Thanks. Got registered separately now. Regards, Sricharan