diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-08-02 10:57:39 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-08-02 10:57:39 -0700 |
commit | 3f9c08f7ce2ca7b176dc7ee8dd287a82dfe53e60 (patch) | |
tree | c0813c7f6b9424aaf15ccd2ff227acb71e32d1ff /arch/arm/mm/dma-mapping.c | |
parent | 1f2609460c4a96ef19c6bd2dadea46ad47e6dfa1 (diff) | |
parent | 6bf755db4d5e7ccea61fb17727a183b9bd8945b1 (diff) |
Merge branch 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm
Pull ARM fixes from Russell King:
"A few fixes for ARM. Some of these are correctness issues:
- TLBs must be flushed after the old mappings are removed by the DMA
mapping code, but before the new mappings are established.
- An off-by-one entry error in the Keystone LPAE setup code.
Fixes include:
- ensuring that the identity mapping for LPAE does not remove the
kernel image from the identity map.
- preventing userspace from trapping into kgdb.
- fixing a preemption issue in the Intel iwmmxt code.
- fixing a build error with nommu.
Other changes include:
- Adding a note about which areas of memory are expected to be
accessible while the identity mapping tables are in place"
* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
ARM: 8124/1: don't enter kgdb when userspace executes a kgdb break instruction
ARM: idmap: add identity mapping usage note
ARM: 8115/1: LPAE: reduce damage caused by idmap to virtual memory layout
ARM: fix alignment of keystone page table fixup
ARM: 8112/1: only select ARM_PATCH_PHYS_VIRT if MMU is enabled
ARM: 8100/1: Fix preemption disable in iwmmxt_task_enable()
ARM: DMA: ensure that old section mappings are flushed from the TLB
Diffstat (limited to 'arch/arm/mm/dma-mapping.c')
-rw-r--r-- | arch/arm/mm/dma-mapping.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 4c88935654c..1f88db06b13 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -461,12 +461,21 @@ void __init dma_contiguous_remap(void) map.type = MT_MEMORY_DMA_READY; /* - * Clear previous low-memory mapping + * Clear previous low-memory mapping to ensure that the + * TLB does not see any conflicting entries, then flush + * the TLB of the old entries before creating new mappings. + * + * This ensures that any speculatively loaded TLB entries + * (even though they may be rare) can not cause any problems, + * and ensures that this code is architecturally compliant. */ for (addr = __phys_to_virt(start); addr < __phys_to_virt(end); addr += PMD_SIZE) pmd_clear(pmd_off_k(addr)); + flush_tlb_kernel_range(__phys_to_virt(start), + __phys_to_virt(end)); + iotable_init(&map, 1); } } |