kernel.git/arch/arm/mm, branch linux-3.19.y

mm/hugetlb: reduce arch dependent code around follow_huge_*

2015-04-29T08:23:47Z

commit 61f77eda9bbf0d2e922197ed2dcf88638a639ce5 upstream. Currently we have many duplicates in definitions around follow_huge_addr(), follow_huge_pmd(), and follow_huge_pud(), so this patch tries to remove the m. The basic idea is to put the default implementation for these functions in mm/hugetlb.c as weak symbols (regardless of CONFIG_ARCH_WANT_GENERAL_HUGETL B), and to implement arch-specific code only when the arch needs it. For follow_huge_addr(), only powerpc and ia64 have their own implementation, and in all other architectures this function just returns ERR_PTR(-EINVAL). So this patch sets returning ERR_PTR(-EINVAL) as default. As for follow_huge_(pmd|pud)(), if (pmd|pud)_huge() is implemented to always return 0 in your architecture (like in ia64 or sparc,) it's never called (the callsite is optimized away) no matter how implemented it is. So in such architectures, we don't need arch-specific implementation. In some architecture (like mips, s390 and tile,) their current arch-specific follow_huge_(pmd|pud)() are effectively identical with the common code, so this patch lets these architecture use the common code. One exception is metag, where pmd_huge() could return non-zero but it expects follow_huge_pmd() to always return NULL. This means that we need arch-specific implementation which returns NULL. This behavior looks strange to me (because non-zero pmd_huge() implies that the architecture supports PMD-based hugepage, so follow_huge_pmd() can/should return some relevant value,) but that's beyond this cleanup patch, so let's keep it. Justification of non-trivial changes: - in s390, follow_huge_pmd() checks !MACHINE_HAS_HPAGE at first, and this patch removes the check. This is OK because we can assume MACHINE_HAS_HPAGE is true when follow_huge_pmd() can be called (note that pmd_huge() has the same check and always returns 0 for !MACHINE_HAS_HPAGE.) - in s390 and mips, we use HPAGE_MASK instead of PMD_MASK as done in common code. This patch forces these archs use PMD_MASK, but it's OK because they are identical in both archs. In s390, both of HPAGE_SHIFT and PMD_SHIFT are 20. In mips, HPAGE_SHIFT is defined as (PAGE_SHIFT + PAGE_SHIFT - 3) and PMD_SHIFT is define as (PAGE_SHIFT + PAGE_SHIFT + PTE_ORDER - 3), but PTE_ORDER is always 0, so these are identical. [n-horiguchi@ah.jp.nec.com: resolve conflict to apply to v3.19.1] Signed-off-by: Naoya Horiguchi Acked-by: Hugh Dickins Cc: James Hogan Cc: David Rientjes Cc: Mel Gorman Cc: Johannes Weiner Cc: Michal Hocko Cc: Rik van Riel Cc: Andrea Arcangeli Cc: Luiz Capitulino Cc: Nishanth Aravamudan Cc: Lee Schermerhorn Cc: Steve Capper Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

Merge branch 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm

2015-02-04T17:42:55Z

Pull ARM fixes from Russell King: "A number of ARM fixes, the biggest is fixing a regression caused by appended DT blobs exceeding 64K, causing the decompressor fixup code to fail to patch the DT blob. Another important fix is for the ASID allocator from Will Deacon which prevents some rare crashes seen on some systems. Lastly, there's a build fix for v7M systems when printk support is disabled. The last two remaining fixes are more cosmetic - the IOMMU one prevents an annoying harmless warning message, and we disable the kernel strict memory permissions on non-MMU which can't support it anyway" * 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm: ARM: 8299/1: mm: ensure local active ASID is marked as allocated on rollover ARM: 8298/1: ARM_KERNMEM_PERMS only works with MMU enabled ARM: 8295/1: fix v7M build for !CONFIG_PRINTK ARM: 8294/1: ATAG_DTB_COMPAT: remove the DT workspace's hardcoded 64KB size ARM: 8288/1: dma-mapping: don't detach devices without an IOMMU during teardown

ARM: 8299/1: mm: ensure local active ASID is marked as allocated on rollover

2015-02-03T12:57:33Z

Commit e1a5848e3398 ("ARM: 7924/1: mm: don't bother with reserved ttbr0 when running with LPAE") removed the use of the reserved TTBR0 value for LPAE systems, since the ASID is held in the TTBR and can be updated atomicly with the pgd of the next mm. Unfortunately, this patch forgot to update flush_context, which deliberately avoids marking the local active ASID as allocated, since we used to switch via ASID zero and didn't need to allocate the ASID of the previous mm. The side-effect of this is that we can allocate the same ASID to the next mm and, between flushing the local TLB and updating TTBR0, we can perform speculative TLB fills for userspace nG mappings using the page table of the previous mm. The consequence of this is that the next mm can erroneously hit some mappings of the previous mm. Note that this was made significantly harder to hit by a391263cd84e ("ARM: 8203/1: mm: try to re-use old ASID assignments following a rollover") but is still theoretically possible. This patch fixes the problem by removing the code from flush_context that forces the allocated ASID to zero for the local CPU. Many thanks to the Broadcom guys for tracking this one down. Fixes: e1a5848e3398 ("ARM: 7924/1: mm: don't bother with reserved ttbr0 when running with LPAE") Cc: # v3.14+ Reported-by: Raymond Ngun Tested-by: Raymond Ngun Reviewed-by: Gregory Fong Signed-off-by: Will Deacon Signed-off-by: Russell King

arm: dma-mapping: Set DMA IOMMU ops in arm_iommu_attach_device()

2015-01-29T18:56:27Z

Commit 4bb25789ed28228a ("arm: dma-mapping: plumb our iommu mapping ops into arch_setup_dma_ops") moved the setting of the DMA operations from arm_iommu_attach_device() to arch_setup_dma_ops() where the DMA operations to be used are selected based on whether the device is connected to an IOMMU. However, the IOMMU detection scheme requires the IOMMU driver to be ported to the new IOMMU of_xlate API. As no driver has been ported yet, this effectively breaks all IOMMU ARM users that depend on the IOMMU being handled transparently by the DMA mapping API. Fix this by restoring the setting of DMA IOMMU ops in arm_iommu_attach_device() and splitting the rest of the function into a new internal __arm_iommu_attach_device() function, called by arch_setup_dma_ops(). Signed-off-by: Laurent Pinchart Acked-by: Will Deacon Tested-by: Heiko Stuebner Signed-off-by: Olof Johansson

ARM: 8298/1: ARM_KERNMEM_PERMS only works with MMU enabled

2015-01-29T15:23:31Z

The recently added ARM_KERNMEM_PERMS feature works by manipulating the kernel page tables, which obviously requires an MMU. Trying to enable this feature when the MMU is disabled results in a lot of compile errors in mm/init.c, so let's add a Kconfig dependency to avoid that case. Signed-off-by: Arnd Bergmann Signed-off-by: Russell King

ARM: 8288/1: dma-mapping: don't detach devices without an IOMMU during teardown

2015-01-29T15:22:44Z

When tearing down the DMA ops for a device via of_dma_deconfigure, we unconditionally detach the device from its IOMMU domain. For devices that aren't actually behind an IOMMU, this produces a "Not attached" warning message on the console. This patch changes the teardown code so that we don't detach from the IOMMU domain when there isn't an IOMMU dma mapping to start with. Reported-by: Laurent Pinchart Signed-off-by: Will Deacon Signed-off-by: Russell King

ARM: 8275/1: mm: fix PMD_SECT_RDONLY undeclared compile error

2015-01-09T20:44:12Z

In v3.19-rc3 tree when CONFIG_ARM_LPAE and CONFIG_DEBUG_RODATA are enabled image failed to compile with the following error: arch/arm/mm/init.c:661:14: error: ‘PMD_SECT_RDONLY’ undeclared here (not in a function) It seems that '80d6b0c ARM: mm: allow text and rodata sections to be read-only' and 'ded9477 ARM: 8109/1: mm: Modify pte_write and pmd_write logic for LPAE' commits crossed. 80d6b0c uses PMD_SECT_RDONLY macro but ded9477 renames it and uses software bits L_PMD_SECT_RDONLY instead. Fix is to use L_PMD_SECT_RDONLY instead PMD_SECT_RDONLY as ded9477 does in another places. Signed-off-by: Victor Kamensky Acked-by: Will Deacon Signed-off-by: Russell King

ARM: 8253/1: mm: use phys_addr_t type in map_lowmem() for kernel mem region

2015-01-07T20:33:34Z

Now local variables kernel_x_start and kernel_x_end defined using 'unsigned long' type which is wrong because they represent physical memory range and will be calculated wrongly if LPAE is enabled. As result, all following code in map_lowmem() will not work correctly. For example, Keystone 2 boot is broken because kernel_x_start == 0x0000 0000 kernel_x_end == 0x0080 0000 instead of kernel_x_start == 0x0000 0008 0000 0000 kernel_x_end == 0x0000 0008 0080 0000 and as result whole low memory will be mapped with MT_MEMORY_RW permissions by code (start > kernel_x_end): } else if (start >= kernel_x_end) { map.pfn = __phys_to_pfn(start); map.virtual = __phys_to_virt(start); map.length = end - start; map.type = MT_MEMORY_RW; create_mapping(&map); } Hence, fix it by using phys_addr_t type for variables kernel_x_start and kernel_x_end. Tested-by: Murali Karicheri Signed-off-by: Grygorii Strashko Signed-off-by: Russell King

ARM: 8249/1: mm: dump: don't skip regions

2015-01-07T20:33:33Z

Currently the arm page table dumping code starts dumping page tables from USER_PGTABLES_CEILING. This is unnecessary for skipping any entries related to userspace as the swapper_pg_dir does not contain such entries, and results in a couple of unfortuante side effects. Firstly, any kernel mappings which might exist below USER_PGTABLES_CEILING will not be accounted in the dump output. This masks any entries erroneously created below this address. Secondly, if the final page table entry walked is part of a valid mapping the page table dumping code will not log the region this entry is part of, as the final note_page call in walk_pgd will trigger an early return when 0 < USER_PGTABLES_CEILING. Luckily this isn't seen on contemporary systems as they typically don't have enough RAM to extend the linear mapping right to the end of the address space. Due to the way addr is constructed in the walk_* functions, it can never be less than USER_PGTABLES_CEILING when walking the page tables, so it is not necessary to avoid dereferencing invalid table addresses. The existing checks for st->current_prot and st->marker[1].start_address are sufficient to ensure we will not print and/or dereference garbage when trying to log information. This patch removes both problematic uses of USER_PGTABLES_CEILING from the arm page table dumping code, preventing both of these issues. We will now report any low mappings, and the final note_page call will not return early, ensuring all regions are logged. Signed-off-by: Mark Rutland Cc: Steve Capper Cc: Kees Cook Cc: Will Deacon Signed-off-by: Russell King

Merge tag 'iommu-config-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

2014-12-16T22:53:01Z

Pull ARM SoC/iommu configuration update from Arnd Bergmann: "The iomm-config branch contains work from Will Deacon, quoting his description: This series adds automatic IOMMU and DMA-mapping configuration for OF-based DMA masters described using the generic IOMMU devicetree bindings. Although there is plenty of future work around splitting up iommu_ops, adding default IOMMU domains and sorting out automatic IOMMU group creation for the platform_bus, this is already useful enough for people to port over their IOMMU drivers and start using the new probing infrastructure (indeed, Marek has patches queued for the Exynos IOMMU). The branch touches core ARM and IOMMU driver files, and the respective maintainers (Russell King and Joerg Roedel) agreed to have the contents merged through the arm-soc tree. The final version was ready just before the merge window, so we ended up delaying it a bit longer than the rest, but we don't expect to see regressions because this is just additional infrastructure that will get used in drivers starting in 3.20 but is unused so far" * tag 'iommu-config-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: iommu: store DT-probed IOMMU data privately arm: dma-mapping: plumb our iommu mapping ops into arch_setup_dma_ops arm: call iommu_init before of_platform_populate dma-mapping: detect and configure IOMMU in of_dma_configure iommu: fix initialization without 'add_device' callback iommu: provide helper function to configure an IOMMU for an of master iommu: add new iommu_ops callback for adding an OF device dma-mapping: replace set_arch_dma_coherent_ops with arch_setup_dma_ops iommu: provide early initialisation hook for IOMMU drivers