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author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-07-01 11:02:25 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-07-01 11:02:25 -0700 |
commit | ca24a145573124732152daff105ba68cc9a2b545 (patch) | |
tree | 14c32a9f4d73228aa10d58776286a31d55a62f9e | |
parent | 6887a4131da3adaab011613776d865f4bcfb5678 (diff) | |
parent | 19b52abe3c5d759661500a1dc810924369b2ad46 (diff) | |
download | op-kernel-dev-ca24a145573124732152daff105ba68cc9a2b545.zip op-kernel-dev-ca24a145573124732152daff105ba68cc9a2b545.tar.gz |
Merge branch 'fixes' of git://git.linaro.org/people/rmk/linux-arm
Pull two ARM fixes from Russell King:
"It's been fairly quiet with the fixes. Just two this time. One fixes
a long standing problem with KALLSYMS needing an additional pass, and
the other sorts a problem with the vmalloc space interacting with
static IO mappings."
* 'fixes' of git://git.linaro.org/people/rmk/linux-arm:
ARM: 7438/1: fill possible PMD empty section gaps
ARM: 7428/1: Prevent KALLSYM size mismatch on ARM.
-rw-r--r-- | arch/arm/kernel/vmlinux.lds.S | 2 | ||||
-rw-r--r-- | arch/arm/mm/mmu.c | 74 |
2 files changed, 76 insertions, 0 deletions
diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S index 43a31fb..36ff15b 100644 --- a/arch/arm/kernel/vmlinux.lds.S +++ b/arch/arm/kernel/vmlinux.lds.S @@ -183,7 +183,9 @@ SECTIONS } #endif +#ifdef CONFIG_SMP PERCPU_SECTION(L1_CACHE_BYTES) +#endif #ifdef CONFIG_XIP_KERNEL __data_loc = ALIGN(4); /* location in binary */ diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index e5dad60..cf4528d 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -791,6 +791,79 @@ void __init iotable_init(struct map_desc *io_desc, int nr) } } +#ifndef CONFIG_ARM_LPAE + +/* + * The Linux PMD is made of two consecutive section entries covering 2MB + * (see definition in include/asm/pgtable-2level.h). However a call to + * create_mapping() may optimize static mappings by using individual + * 1MB section mappings. This leaves the actual PMD potentially half + * initialized if the top or bottom section entry isn't used, leaving it + * open to problems if a subsequent ioremap() or vmalloc() tries to use + * the virtual space left free by that unused section entry. + * + * Let's avoid the issue by inserting dummy vm entries covering the unused + * PMD halves once the static mappings are in place. + */ + +static void __init pmd_empty_section_gap(unsigned long addr) +{ + struct vm_struct *vm; + + vm = early_alloc_aligned(sizeof(*vm), __alignof__(*vm)); + vm->addr = (void *)addr; + vm->size = SECTION_SIZE; + vm->flags = VM_IOREMAP | VM_ARM_STATIC_MAPPING; + vm->caller = pmd_empty_section_gap; + vm_area_add_early(vm); +} + +static void __init fill_pmd_gaps(void) +{ + struct vm_struct *vm; + unsigned long addr, next = 0; + pmd_t *pmd; + + /* we're still single threaded hence no lock needed here */ + for (vm = vmlist; vm; vm = vm->next) { + if (!(vm->flags & VM_ARM_STATIC_MAPPING)) + continue; + addr = (unsigned long)vm->addr; + if (addr < next) + continue; + + /* + * Check if this vm starts on an odd section boundary. + * If so and the first section entry for this PMD is free + * then we block the corresponding virtual address. + */ + if ((addr & ~PMD_MASK) == SECTION_SIZE) { + pmd = pmd_off_k(addr); + if (pmd_none(*pmd)) + pmd_empty_section_gap(addr & PMD_MASK); + } + + /* + * Then check if this vm ends on an odd section boundary. + * If so and the second section entry for this PMD is empty + * then we block the corresponding virtual address. + */ + addr += vm->size; + if ((addr & ~PMD_MASK) == SECTION_SIZE) { + pmd = pmd_off_k(addr) + 1; + if (pmd_none(*pmd)) + pmd_empty_section_gap(addr); + } + + /* no need to look at any vm entry until we hit the next PMD */ + next = (addr + PMD_SIZE - 1) & PMD_MASK; + } +} + +#else +#define fill_pmd_gaps() do { } while (0) +#endif + static void * __initdata vmalloc_min = (void *)(VMALLOC_END - (240 << 20) - VMALLOC_OFFSET); @@ -1072,6 +1145,7 @@ static void __init devicemaps_init(struct machine_desc *mdesc) */ if (mdesc->map_io) mdesc->map_io(); + fill_pmd_gaps(); /* * Finally flush the caches and tlb to ensure that we're in a |