linux/drivers/iommu, branch v4.4

iommu/dma: Use correct offset in map_sg

2016-01-07T12:36:41Z

When mapping a non-page-aligned scatterlist entry, we copy the original offset to the output DMA address before aligning it to hand off to iommu_map_sg(), then later adding the IOVA page address portion to get the final mapped address. However, when the IOVA page size is smaller than the CPU page size, it is the offset within the IOVA page we want, not that within the CPU page, which can easily be larger than an IOVA page and thus result in an incorrect final address. Fix the bug by taking only the IOVA-aligned part of the offset as the basis of the DMA address, not the whole thing. Signed-off-by: Robin Murphy Signed-off-by: Joerg Roedel

iommu/ipmmu-vmsa: Don't truncate ttbr if LPAE is not enabled

2015-12-28T16:10:52Z

If CONFIG_PHYS_ADDR_T_64BIT=n: drivers/iommu/ipmmu-vmsa.c: In function 'ipmmu_domain_init_context': drivers/iommu/ipmmu-vmsa.c:434:2: warning: right shift count >= width of type ipmmu_ctx_write(domain, IMTTUBR0, ttbr >> 32); ^ As io_pgtable_cfg.arm_lpae_s1_cfg.ttbr[] is an array of u64s, assigning it to a phys_addr_t may truncates it. Make ttbr u64 to fix this. Signed-off-by: Geert Uytterhoeven Signed-off-by: Joerg Roedel

iommu/dma: Avoid unlikely high-order allocations

2015-12-28T16:06:26Z

Doug reports that the equivalent page allocator on 32-bit ARM exhibits particularly pathalogical behaviour under memory pressure when fragmentation is high, where allocating a 4MB buffer takes tens of seconds and the number of calls to alloc_pages() is over 9000![1] We can drastically improve that situation without losing the other benefits of high-order allocations when they would succeed, by assuming memory pressure is relatively constant over the course of an allocation, and not retrying allocations at orders we know to have failed before. This way, the best-case behaviour remains unchanged, and in the worst case we should see at most a dozen or so (MAX_ORDER - 1) failed attempts before falling back to single pages for the remainder of the buffer. [1]:http://lists.infradead.org/pipermail/linux-arm-kernel/2015-December/394660.html Reported-by: Douglas Anderson Signed-off-by: Robin Murphy Signed-off-by: Joerg Roedel

iommu/dma: Add some missing #includes

2015-12-28T16:03:34Z

dma-iommu.c was naughtily relying on an implicit transitive #include of linux/vmalloc.h, which is apparently not present on some architectures. Add that, plus a couple more headers for other functions which are used similarly. Reported-by: kbuild test robot Signed-off-by: Robin Murphy Signed-off-by: Joerg Roedel

Merge tag 'iommu-fixes-v4.4-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu

2015-12-18T20:38:35Z

Pull IOMMU fixes from Joerg Roedel: "Two similar fixes for the Intel and AMD IOMMU drivers to add proper access checks before calling handle_mm_fault" * tag 'iommu-fixes-v4.4-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: iommu/vt-d: Do access checks before calling handle_mm_fault() iommu/amd: Do proper access checking before calling handle_mm_fault()

Revert "scatterlist: use sg_phys()"

2015-12-15T20:54:06Z

commit db0fa0cb0157 "scatterlist: use sg_phys()" did replacements of the form: phys_addr_t phys = page_to_phys(sg_page(s)); phys_addr_t phys = sg_phys(s) & PAGE_MASK; However, this breaks platforms where sizeof(phys_addr_t) > sizeof(unsigned long). Revert for 4.3 and 4.4 to make room for a combined helper in 4.5. Cc: Cc: Jens Axboe Cc: Christoph Hellwig Cc: Russell King Cc: David Woodhouse Cc: Andrew Morton Fixes: db0fa0cb0157 ("scatterlist: use sg_phys()") Suggested-by: Joerg Roedel Reported-by: Vitaly Lavrov Signed-off-by: Dan Williams

iommu/vt-d: Do access checks before calling handle_mm_fault()

2015-12-14T14:37:55Z

Not doing so is a bug and might trigger a BUG_ON in handle_mm_fault(). So add the proper permission checks before calling into mm code. Reviewed-by: Jesse Barnes Acked-By: David Woodhouse Signed-off-by: Joerg Roedel

iommu/amd: Do proper access checking before calling handle_mm_fault()

2015-12-14T14:37:47Z

The handle_mm_fault function expects the caller to do the access checks. Not doing so and calling the function with wrong permissions is a bug (catched by a BUG_ON). So fix this bug by adding proper access checking to the io page-fault code in the AMD IOMMUv2 driver. Reviewed-by: Jesse Barnes Acked-By: David Woodhouse Signed-off-by: Joerg Roedel

s390/pci_dma: handle dma table failures

2015-11-09T08:10:49Z

We use lazy allocation for translation table entries but don't handle allocation (and other) failures during translation table updates. Handle these failures and undo translation table updates when it's meaningful. Signed-off-by: Sebastian Ott Reviewed-by: Gerald Schaefer Signed-off-by: Martin Schwidefsky

mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd

2015-11-07T01:50:42Z

__GFP_WAIT has been used to identify atomic context in callers that hold spinlocks or are in interrupts. They are expected to be high priority and have access one of two watermarks lower than "min" which can be referred to as the "atomic reserve". __GFP_HIGH users get access to the first lower watermark and can be called the "high priority reserve". Over time, callers had a requirement to not block when fallback options were available. Some have abused __GFP_WAIT leading to a situation where an optimisitic allocation with a fallback option can access atomic reserves. This patch uses __GFP_ATOMIC to identify callers that are truely atomic, cannot sleep and have no alternative. High priority users continue to use __GFP_HIGH. __GFP_DIRECT_RECLAIM identifies callers that can sleep and are willing to enter direct reclaim. __GFP_KSWAPD_RECLAIM to identify callers that want to wake kswapd for background reclaim. __GFP_WAIT is redefined as a caller that is willing to enter direct reclaim and wake kswapd for background reclaim. This patch then converts a number of sites o __GFP_ATOMIC is used by callers that are high priority and have memory pools for those requests. GFP_ATOMIC uses this flag. o Callers that have a limited mempool to guarantee forward progress clear __GFP_DIRECT_RECLAIM but keep __GFP_KSWAPD_RECLAIM. bio allocations fall into this category where kswapd will still be woken but atomic reserves are not used as there is a one-entry mempool to guarantee progress. o Callers that are checking if they are non-blocking should use the helper gfpflags_allow_blocking() where possible. This is because checking for __GFP_WAIT as was done historically now can trigger false positives. Some exceptions like dm-crypt.c exist where the code intent is clearer if __GFP_DIRECT_RECLAIM is used instead of the helper due to flag manipulations. o Callers that built their own GFP flags instead of starting with GFP_KERNEL and friends now also need to specify __GFP_KSWAPD_RECLAIM. The first key hazard to watch out for is callers that removed __GFP_WAIT and was depending on access to atomic reserves for inconspicuous reasons. In some cases it may be appropriate for them to use __GFP_HIGH. The second key hazard is callers that assembled their own combination of GFP flags instead of starting with something like GFP_KERNEL. They may now wish to specify __GFP_KSWAPD_RECLAIM. It's almost certainly harmless if it's missed in most cases as other activity will wake kswapd. Signed-off-by: Mel Gorman Acked-by: Vlastimil Babka Acked-by: Michal Hocko Acked-by: Johannes Weiner Cc: Christoph Lameter Cc: David Rientjes Cc: Vitaly Wool Cc: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds