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2018-08-17ioremap: Update pgtable free interfaces with addrChintan Pandya
commit 785a19f9d1dd8a4ab2d0633be4656653bd3de1fc upstream. The following kernel panic was observed on ARM64 platform due to a stale TLB entry. 1. ioremap with 4K size, a valid pte page table is set. 2. iounmap it, its pte entry is set to 0. 3. ioremap the same address with 2M size, update its pmd entry with a new value. 4. CPU may hit an exception because the old pmd entry is still in TLB, which leads to a kernel panic. Commit b6bdb7517c3d ("mm/vmalloc: add interfaces to free unmapped page table") has addressed this panic by falling to pte mappings in the above case on ARM64. To support pmd mappings in all cases, TLB purge needs to be performed in this case on ARM64. Add a new arg, 'addr', to pud_free_pmd_page() and pmd_free_pte_page() so that TLB purge can be added later in seprate patches. [toshi.kani@hpe.com: merge changes, rewrite patch description] Fixes: 28ee90fe6048 ("x86/mm: implement free pmd/pte page interfaces") Signed-off-by: Chintan Pandya <cpandya@codeaurora.org> Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: mhocko@suse.com Cc: akpm@linux-foundation.org Cc: hpa@zytor.com Cc: linux-mm@kvack.org Cc: linux-arm-kernel@lists.infradead.org Cc: Will Deacon <will.deacon@arm.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: stable@vger.kernel.org Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20180627141348.21777-3-toshi.kani@hpe.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-03-28mm/vmalloc: add interfaces to free unmapped page tableToshi Kani
commit b6bdb7517c3d3f41f20e5c2948d6bc3f8897394e upstream. On architectures with CONFIG_HAVE_ARCH_HUGE_VMAP set, ioremap() may create pud/pmd mappings. A kernel panic was observed on arm64 systems with Cortex-A75 in the following steps as described by Hanjun Guo. 1. ioremap a 4K size, valid page table will build, 2. iounmap it, pte0 will set to 0; 3. ioremap the same address with 2M size, pgd/pmd is unchanged, then set the a new value for pmd; 4. pte0 is leaked; 5. CPU may meet exception because the old pmd is still in TLB, which will lead to kernel panic. This panic is not reproducible on x86. INVLPG, called from iounmap, purges all levels of entries associated with purged address on x86. x86 still has memory leak. The patch changes the ioremap path to free unmapped page table(s) since doing so in the unmap path has the following issues: - The iounmap() path is shared with vunmap(). Since vmap() only supports pte mappings, making vunmap() to free a pte page is an overhead for regular vmap users as they do not need a pte page freed up. - Checking if all entries in a pte page are cleared in the unmap path is racy, and serializing this check is expensive. - The unmap path calls free_vmap_area_noflush() to do lazy TLB purges. Clearing a pud/pmd entry before the lazy TLB purges needs extra TLB purge. Add two interfaces, pud_free_pmd_page() and pmd_free_pte_page(), which clear a given pud/pmd entry and free up a page for the lower level entries. This patch implements their stub functions on x86 and arm64, which work as workaround. [akpm@linux-foundation.org: fix typo in pmd_free_pte_page() stub] Link: http://lkml.kernel.org/r/20180314180155.19492-2-toshi.kani@hpe.com Fixes: e61ce6ade404e ("mm: change ioremap to set up huge I/O mappings") Reported-by: Lei Li <lious.lilei@hisilicon.com> Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Wang Xuefeng <wxf.wang@hisilicon.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Hanjun Guo <guohanjun@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Borislav Petkov <bp@suse.de> Cc: Matthew Wilcox <willy@infradead.org> Cc: Chintan Pandya <cpandya@codeaurora.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-14x86, mm: support huge KVA mappings on x86Toshi Kani
Implement huge KVA mapping interfaces on x86. On x86, MTRRs can override PAT memory types with a 4KB granularity. When using a huge page, MTRRs can override the memory type of the huge page, which may lead a performance penalty. The processor can also behave in an undefined manner if a huge page is mapped to a memory range that MTRRs have mapped with multiple different memory types. Therefore, the mapping code falls back to use a smaller page size toward 4KB when a mapping range is covered by non-WB type of MTRRs. The WB type of MTRRs has no affect on the PAT memory types. pud_set_huge() and pmd_set_huge() call mtrr_type_lookup() to see if a given range is covered by MTRRs. MTRR_TYPE_WRBACK indicates that the range is either covered by WB or not covered and the MTRR default value is set to WB. 0xFF indicates that MTRRs are disabled. HAVE_ARCH_HUGE_VMAP is selected when X86_64 or X86_32 with X86_PAE is set. X86_32 without X86_PAE is not supported since such config can unlikey be benefited from this feature, and there was an issue found in testing. [fengguang.wu@intel.com: ioremap_pud_capable can be static] Signed-off-by: Toshi Kani <toshi.kani@hp.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Robert Elliott <Elliott@hp.com> Signed-off-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14mm: change ioremap to set up huge I/O mappingsToshi Kani
ioremap_pud_range() and ioremap_pmd_range() are changed to create huge I/O mappings when their capability is enabled, and a request meets required conditions -- both virtual & physical addresses are aligned by their huge page size, and a requested range fufills their huge page size. When pud_set_huge() or pmd_set_huge() returns zero, i.e. no-operation is performed, the code simply falls back to the next level. The changes are only enabled when CONFIG_HAVE_ARCH_HUGE_VMAP is defined on the architecture. Signed-off-by: Toshi Kani <toshi.kani@hp.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Robert Elliott <Elliott@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-14lib/ioremap.c: add huge I/O map capability interfacesToshi Kani
Add ioremap_pud_enabled() and ioremap_pmd_enabled(), which return 1 when I/O mappings with pud/pmd are enabled on the kernel. ioremap_huge_init() calls arch_ioremap_pud_supported() and arch_ioremap_pmd_supported() to initialize the capabilities at boot-time. A new kernel option "nohugeiomap" is also added, so that user can disable the huge I/O map capabilities when necessary. Signed-off-by: Toshi Kani <toshi.kani@hp.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Robert Elliott <Elliott@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-07lib: reduce the use of module.h wherever possiblePaul Gortmaker
For files only using THIS_MODULE and/or EXPORT_SYMBOL, map them onto including export.h -- or if the file isn't even using those, then just delete the include. Fix up any implicit include dependencies that were being masked by module.h along the way. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-01-12ACPI, APEI, Generic Hardware Error Source POLL/IRQ/NMI notification type supportHuang Ying
Generic Hardware Error Source provides a way to report platform hardware errors (such as that from chipset). It works in so called "Firmware First" mode, that is, hardware errors are reported to firmware firstly, then reported to Linux by firmware. This way, some non-standard hardware error registers or non-standard hardware link can be checked by firmware to produce more valuable hardware error information for Linux. This patch adds POLL/IRQ/NMI notification types support. Because the memory area used to transfer hardware error information from BIOS to Linux can be determined only in NMI, IRQ or timer handler, but general ioremap can not be used in atomic context, so a special version of atomic ioremap is implemented for that. Known issue: - Error information can not be printed for recoverable errors notified via NMI, because printk is not NMI-safe. Will fix this via delay printing to IRQ context via irq_work or make printk NMI-safe. v2: - adjust printk format per comments. Signed-off-by: Huang Ying <ying.huang@intel.com> Reviewed-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
2010-07-09x86, ioremap: Fix incorrect physical address handling in PAE modeKenji Kaneshige
Current x86 ioremap() doesn't handle physical address higher than 32-bit properly in X86_32 PAE mode. When physical address higher than 32-bit is passed to ioremap(), higher 32-bits in physical address is cleared wrongly. Due to this bug, ioremap() can map wrong address to linear address space. In my case, 64-bit MMIO region was assigned to a PCI device (ioat device) on my system. Because of the ioremap()'s bug, wrong physical address (instead of MMIO region) was mapped to linear address space. Because of this, loading ioatdma driver caused unexpected behavior (kernel panic, kernel hangup, ...). Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> LKML-Reference: <4C1AE680.7090408@jp.fujitsu.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2007-10-17lib/ioremap.c should #include <linux/io.h>Adrian Bunk
Every file should include the headers containing the prototypes for its global functions (in this case ioremap_page_range()). Signed-off-by: Adrian Bunk <bunk@stusta.de> Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-21Detach sched.h from mm.hAlexey Dobriyan
First thing mm.h does is including sched.h solely for can_do_mlock() inline function which has "current" dereference inside. By dealing with can_do_mlock() mm.h can be detached from sched.h which is good. See below, why. This patch a) removes unconditional inclusion of sched.h from mm.h b) makes can_do_mlock() normal function in mm/mlock.c c) exports can_do_mlock() to not break compilation d) adds sched.h inclusions back to files that were getting it indirectly. e) adds less bloated headers to some files (asm/signal.h, jiffies.h) that were getting them indirectly Net result is: a) mm.h users would get less code to open, read, preprocess, parse, ... if they don't need sched.h b) sched.h stops being dependency for significant number of files: on x86_64 allmodconfig touching sched.h results in recompile of 4083 files, after patch it's only 3744 (-8.3%). Cross-compile tested on all arm defconfigs, all mips defconfigs, all powerpc defconfigs, alpha alpha-up arm i386 i386-up i386-defconfig i386-allnoconfig ia64 ia64-up m68k mips parisc parisc-up powerpc powerpc-up s390 s390-up sparc sparc-up sparc64 sparc64-up um-x86_64 x86_64 x86_64-up x86_64-defconfig x86_64-allnoconfig as well as my two usual configs. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2006-12-13[PATCH] uml problems with linux/io.hAl Viro
Remove useless includes of linux/io.h, don't even try to build iomap_copy on uml (it doesn't have readb() et.al., so...) Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Acked-by: Jeff Dike <jdike@addtoit.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01[PATCH] Generic ioremap_page_range: flush_cache_vmapHaavard Skinnemoen
The existing implementation of ioremap_page_range(), which was taken from i386, does this: flush_cache_all(); /* modify page tables */ flush_tlb_all(); I think this is a bit defensive, so this patch changes the generic implementation to do: /* modify page tables */ flush_cache_vmap(start, end); instead, which is similar to what vmalloc() does. This should still be correct because we never modify existing PTEs. According to James Bottomley: The problem the flush_tlb_all() is trying to solve is to avoid stale tlb entries in the ioremap area. We're just being conservative by flushing on both map and unmap. Technically what vmalloc/vfree does (only flush the tlb on unmap) is just fine because it means that the only tlb entries in the remap area must belong to in-use mappings. Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Mikael Starvik <starvik@axis.com> Cc: Andi Kleen <ak@suse.de> Cc: <linux-m32r@ml.linux-m32r.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Kyle McMartin <kyle@parisc-linux.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-01[PATCH] Generic ioremap_page_range: implementationHaavard Skinnemoen
This patch adds a generic implementation of ioremap_page_range() in lib/ioremap.c based on the i386 implementation. It differs from the i386 version in the following ways: * The PTE flags are passed as a pgprot_t argument and must be determined up front by the arch-specific code. No additional PTE flags are added. * Uses set_pte_at() instead of set_pte() [bunk@stusta.de: warning fix] ]dhowells@redhat.com: nommu build fix] Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Mikael Starvik <starvik@axis.com> Cc: Andi Kleen <ak@suse.de> Cc: <linux-m32r@ml.linux-m32r.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Kyle McMartin <kyle@parisc-linux.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>