kernel/linux.git/arch/powerpc/mm/mem.c, branch linux-4.4.y

powerpc: Ensure that swiotlb buffer is allocated from low memory

2020-01-12T10:22:48+00:00

[ Upstream commit 8fabc623238e68b3ac63c0dd1657bf86c1fa33af ] Some powerpc platforms (e.g. 85xx) limit DMA-able memory way below 4G. If a system has more physical memory than this limit, the swiotlb buffer is not addressable because it is allocated from memblock using top-down mode. Force memblock to bottom-up mode before calling swiotlb_init() to ensure that the swiotlb buffer is DMA-able. Reported-by: Christian Zigotzky Signed-off-by: Mike Rapoport Reviewed-by: Christoph Hellwig Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20191204123524.22919-1-rppt@kernel.org Signed-off-by: Sasha Levin

powerpc: Avoid code patching freed init sections

2019-05-16T17:44:50+00:00

commit 51c3c62b58b357e8d35e4cc32f7b4ec907426fe3 upstream. This stops us from doing code patching in init sections after they've been freed. In this chain: kvm_guest_init() -> kvm_use_magic_page() -> fault_in_pages_readable() -> __get_user() -> __get_user_nocheck() -> barrier_nospec(); We have a code patching location at barrier_nospec() and kvm_guest_init() is an init function. This whole chain gets inlined, so when we free the init section (hence kvm_guest_init()), this code goes away and hence should no longer be patched. We seen this as userspace memory corruption when using a memory checker while doing partition migration testing on powervm (this starts the code patching post migration via /sys/kernel/mobility/migration). In theory, it could also happen when using /sys/kernel/debug/powerpc/barrier_nospec. Signed-off-by: Michael Neuling Reviewed-by: Nicholas Piggin Reviewed-by: Christophe Leroy Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

Merge tag 'libnvdimm-for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

2015-09-08T21:35:59+00:00

Pull libnvdimm updates from Dan Williams: "This update has successfully completed a 0day-kbuild run and has appeared in a linux-next release. The changes outside of the typical drivers/nvdimm/ and drivers/acpi/nfit.[ch] paths are related to the removal of IORESOURCE_CACHEABLE, the introduction of memremap(), and the introduction of ZONE_DEVICE + devm_memremap_pages(). Summary: - Introduce ZONE_DEVICE and devm_memremap_pages() as a generic mechanism for adding device-driver-discovered memory regions to the kernel's direct map. This facility is used by the pmem driver to enable pfn_to_page() operations on the page frames returned by DAX ('direct_access' in 'struct block_device_operations'). For now, the 'memmap' allocation for these "device" pages comes from "System RAM". Support for allocating the memmap from device memory will arrive in a later kernel. - Introduce memremap() to replace usages of ioremap_cache() and ioremap_wt(). memremap() drops the __iomem annotation for these mappings to memory that do not have i/o side effects. The replacement of ioremap_cache() with memremap() is limited to the pmem driver to ease merging the api change in v4.3. Completion of the conversion is targeted for v4.4. - Similar to the usage of memcpy_to_pmem() + wmb_pmem() in the pmem driver, update the VFS DAX implementation and PMEM api to provide persistence guarantees for kernel operations on a DAX mapping. - Convert the ACPI NFIT 'BLK' driver to map the block apertures as cacheable to improve performance. - Miscellaneous updates and fixes to libnvdimm including support for issuing "address range scrub" commands, clarifying the optimal 'sector size' of pmem devices, a clarification of the usage of the ACPI '_STA' (status) property for DIMM devices, and other minor fixes" * tag 'libnvdimm-for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (34 commits) libnvdimm, pmem: direct map legacy pmem by default libnvdimm, pmem: 'struct page' for pmem libnvdimm, pfn: 'struct page' provider infrastructure x86, pmem: clarify that ARCH_HAS_PMEM_API implies PMEM mapped WB add devm_memremap_pages mm: ZONE_DEVICE for "device memory" mm: move __phys_to_pfn and __pfn_to_phys to asm/generic/memory_model.h dax: drop size parameter to ->direct_access() nd_blk: change aperture mapping from WC to WB nvdimm: change to use generic kvfree() pmem, dax: have direct_access use __pmem annotation dax: update I/O path to do proper PMEM flushing pmem: add copy_from_iter_pmem() and clear_pmem() pmem, x86: clean up conditional pmem includes pmem: remove layer when calling arch_has_wmb_pmem() pmem, x86: move x86 PMEM API to new pmem.h header libnvdimm, e820: make CONFIG_X86_PMEM_LEGACY a tristate option pmem: switch to devm_ allocations devres: add devm_memremap libnvdimm, btt: write and validate parent_uuid ...

mm: ZONE_DEVICE for "device memory"

2015-08-27T23:40:58+00:00

While pmem is usable as a block device or via DAX mappings to userspace there are several usage scenarios that can not target pmem due to its lack of struct page coverage. In preparation for "hot plugging" pmem into the vmemmap add ZONE_DEVICE as a new zone to tag these pages separately from the ones that are subject to standard page allocations. Importantly "device memory" can be removed at will by userspace unbinding the driver of the device. Having a separate zone prevents allocation and otherwise marks these pages that are distinct from typical uniform memory. Device memory has different lifetime and performance characteristics than RAM. However, since we have run out of ZONES_SHIFT bits this functionality currently depends on sacrificing ZONE_DMA. Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Dave Hansen Cc: Rik van Riel Cc: Mel Gorman Cc: Jerome Glisse [hch: various simplifications in the arch interface] Signed-off-by: Christoph Hellwig Signed-off-by: Dan Williams

powerpc/mm: Don't call __flush_dcache_icache_phys() with PA>VA

2015-08-08T03:59:20+00:00

__flush_dcache_icache_phys() requires the ability to access the memory with the MMU disabled, which means that on a 32-bit system any memory above 4 GiB is inaccessible. In particular, mpc86xx is 32-bit and can have more than 4 GiB of RAM. Signed-off-by: Scott Wood

powerpc/mm: Use PFN_PHYS() in devmem_is_allowed()

2015-06-03T02:37:23+00:00

This function can run on systems where physical addresses don't fit in unsigned long, so make sure to use the macro that contains the proper cast. Signed-off-by: Scott Wood

powerpc: Replace mem_init_done with slab_is_available()

2015-04-10T10:02:48+00:00

We have a powerpc specific global called mem_init_done which is "set on boot once kmalloc can be called". But that's not *quite* true. We set it at the bottom of mem_init(), and rely on the fact that mm_init() calls kmem_cache_init() immediately after that, and nothing is running in parallel. So replace it with the generic and 100% correct slab_is_available(). Signed-off-by: Michael Ellerman

powerpc: Move sparse_init() into initmem_init

2014-11-09T22:59:26+00:00

We did part of sparse initialisation in setup_arch and part in initmem_init. Put them together. Signed-off-by: Anton Blanchard Tested-by: Emil Medve Signed-off-by: Michael Ellerman

powerpc: Remove bootmem allocator

2014-11-09T22:59:25+00:00

At the moment we transition from the memblock alloctor to the bootmem allocator. Gitting rid of the bootmem allocator removes a bunch of complicated code (most of which I owe the dubious honour of being responsible for writing). Signed-off-by: Anton Blanchard Tested-by: Emil Medve Signed-off-by: Michael Ellerman

powerpc: Remove ppc_md.remove_memory

2014-11-05T10:00:46+00:00

We have an extra level of indirection on memory hot remove which is not matched on memory hot add. Memory hotplug is book3s only, so there is no need for it. This also enables means remove_memory() (ie memory hot unplug) works on powernv. Signed-off-by: Anton Blanchard Signed-off-by: Michael Ellerman