summaryrefslogtreecommitdiffstats
path: root/arch/arm/mm/dma-mapping.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2014-08-02 10:57:39 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-08-02 10:57:39 -0700
commit3f9c08f7ce2ca7b176dc7ee8dd287a82dfe53e60 (patch)
treec0813c7f6b9424aaf15ccd2ff227acb71e32d1ff /arch/arm/mm/dma-mapping.c
parent1f2609460c4a96ef19c6bd2dadea46ad47e6dfa1 (diff)
parent6bf755db4d5e7ccea61fb17727a183b9bd8945b1 (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.c11
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);
}
}