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2019-11-11MIPS: Drop CPU_SUPPORTS_UNCACHED_ACCELERATEDJiaxun Yang
CPU_SUPPORTS_UNCACHED_ACCELERATED was introduced when kernel can't handle writecombine remap well. Nowadays drivers can try writecombine remap by themselves so this function is nolonger needed. Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com> Signed-off-by: Paul Burton <paulburton@kernel.org> Cc: linux-mips@vger.kernel.org Cc: chenhe@lemote.com
2019-09-24mm: consolidate pgtable_cache_init() and pgd_cache_init()Mike Rapoport
Both pgtable_cache_init() and pgd_cache_init() are used to initialize kmem cache for page table allocations on several architectures that do not use PAGE_SIZE tables for one or more levels of the page table hierarchy. Most architectures do not implement these functions and use __weak default NOP implementation of pgd_cache_init(). Since there is no such default for pgtable_cache_init(), its empty stub is duplicated among most architectures. Rename the definitions of pgd_cache_init() to pgtable_cache_init() and drop empty stubs of pgtable_cache_init(). Link: http://lkml.kernel.org/r/1566457046-22637-1-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Will Deacon <will@kernel.org> [arm64] Acked-by: Thomas Gleixner <tglx@linutronix.de> [x86] Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-09-03MIPS: Select R3k-style TLB in KconfigPaul Burton
Currently areas where we need to determine whether the TLB is R3k-style need to check for either of CONFIG_CPU_R3000 || CONFIG_CPU_TX39XX. Introduce a new CONFIG_CPU_R3K_TLB & select it from both of the above, allowing us to simplify checks for R3k-style TLBs by only checking for this new Kconfig option. Signed-off-by: Paul Burton <paul.burton@mips.com> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Cc: linux-mips@vger.kernel.org
2019-07-21MIPS: pte_special()/pte_mkspecial() supportDmitry Korotin
Add support for pte_special() & pte_mkspecial(), replacing our previous stubs with functional implementations. Signed-off-by: Dmitry Korotin <dkorotin@wavecomp.com> [paul.burton@mips.com: - Fix for CONFIG_PHYS_ADDR_T_64BIT && CONFIG_CPU_MIPS32. - Rewrite commit message.] Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: linux-mips@vger.kernel.org
2019-07-12MIPS: use the generic get_user_pages_fast codeChristoph Hellwig
The mips code is mostly equivalent to the generic one, minus various bugfixes and an arch override for gup_fast_permitted. Note that this defines ARCH_HAS_PTE_SPECIAL for mips as mips has pte_special and pte_mkspecial implemented and used in the existing gup code. They are no-op stubs, though which makes me a little unsure if this is really right thing to do. Note that this also adds back a missing cpu_has_dc_aliases check for __get_user_pages_fast, which the old code was only doing for get_user_pages_fast. This clearly looks like an oversight, as any condition that makes get_user_pages_fast unsafe also applies to __get_user_pages_fast. [hch@lst.de: MIPS: don't select ARCH_HAS_PTE_SPECIAL] Link: http://lkml.kernel.org/r/20190701151818.32227-3-hch@lst.de Link: http://lkml.kernel.org/r/20190625143715.1689-5-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Tested-by: Guenter Roeck <linux@roeck-us.net> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Miller <davem@davemloft.net> Cc: James Hogan <jhogan@kernel.org> Cc: Khalid Aziz <khalid.aziz@oracle.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Rich Felker <dalias@libc.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-02-06MIPS: Fix set_pte() for Netlogic XLR using cmpxchg64()Paul Burton
Commit 46011e6ea392 ("MIPS: Make set_pte() SMP safe.") introduced an open-coded version of cmpxchg() within set_pte(), that always operated on a value the size of an unsigned long. That is, it used ll/sc instructions when CONFIG_32BIT=y or lld/scd instructions when CONFIG_64BIT=y. This was broken for configurations in which pte_t is larger than an unsigned long (with the exception of XPA configurations which have a different implementation of set_pte()), because we no longer update the whole PTE. Indeed commit 46011e6ea392 ("MIPS: Make set_pte() SMP safe.") notes: > The case of CONFIG_64BIT_PHYS_ADDR && CONFIG_CPU_MIPS32 is *not* > handled. In practice this affects Netlogic XLR/XLS systems including nlm_xlr_defconfig. Commit 82f4f66ddf11 ("MIPS: Remove open-coded cmpxchg() in set_pte()") then replaced this open-coded version of cmpxchg() with an actual call to cmpxchg(). Unfortunately the configurations mentioned above then fail to build because cmpxchg() can only operate on values 32 bits or smaller in size, resulting in: arch/mips/include/asm/cmpxchg.h:166:11: error: call to '__cmpxchg_called_with_bad_pointer' declared with attribute error: Bad argument size for cmpxchg One option that would fix the build failure & restore the previous behaviour would be to cast the pte pointer to a pointer to unsigned long, so that cmpxchg() would operate on just 32 bits of the PTE as it has been since commit 46011e6ea392 ("MIPS: Make set_pte() SMP safe."). That feels like an ugly hack though, and the behaviour of set_pte() is likely a little broken. Instead we take advantage of the fact that the affected configurations already know at compile time that the CPU will support 64 bits (ie. have hardcoded cpu_has_64bits in cpu-feature-overrides.h) in order to allow cmpxchg64() to be used in these configurations. set_pte() then makes use of cmpxchg64() when necessary. Signed-off-by: Paul Burton <paul.burton@mips.com> Fixes: 46011e6ea392 ("MIPS: Make set_pte() SMP safe.") Fixes: 82f4f66ddf11 ("MIPS: Remove open-coded cmpxchg() in set_pte()")
2019-02-04MIPS: Remove open-coded cmpxchg() in set_pte()Paul Burton
set_pte() contains an open coded version of cmpxchg() - it atomically replaces the buddy pte's value if it is currently zero. Simplify the code considerably by just using cmpxchg() instead of reinventing it. Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: linux-mips@vger.kernel.org
2018-11-09MIPS: Avoid using .set mips0 to restore ISAPaul Burton
We currently have 2 commonly used methods for switching ISA within assembly code, then restoring the original ISA. 1) Using a pair of .set push & .set pop directives. For example: .set push .set mips32r2 <some_insn> .set pop 2) Using .set mips0 to restore the ISA originally specified on the command line. For example: .set mips32r2 <some_insn> .set mips0 Unfortunately method 2 does not work with nanoMIPS toolchains, where the assembler rejects the .set mips0 directive like so: Error: cannot change ISA from nanoMIPS to mips0 In preparation for supporting nanoMIPS builds, switch all instances of method 2 in generic non-platform-specific code to use push & pop as in method 1 instead. The .set push & .set pop is arguably cleaner anyway, and if nothing else it's good to consistently use one method. Signed-off-by: Paul Burton <paul.burton@mips.com> Patchwork: https://patchwork.linux-mips.org/patch/21037/ Cc: linux-mips@linux-mips.org
2018-01-31mips: use generic_pmdp_establish as pmdp_establishKirill A. Shutemov
MIPS doesn't support hardware dirty/accessed bits. generic_pmdp_establish() is suitable in this case. Link: http://lkml.kernel.org/r/20171213105756.69879-6-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: David Daney <david.daney@cavium.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-11-29mm: switch to 'define pmd_write' instead of __HAVE_ARCH_PMD_WRITEDan Williams
In response to compile breakage introduced by a series that added the pud_write helper to x86, Stephen notes: did you consider using the other paradigm: In arch include files: #define pud_write pud_write static inline int pud_write(pud_t pud) ..... Then in include/asm-generic/pgtable.h: #ifndef pud_write tatic inline int pud_write(pud_t pud) { .... } #endif If you had, then the powerpc code would have worked ... ;-) and many of the other interfaces in include/asm-generic/pgtable.h are protected that way ... Given that some architecture already define pmd_write() as a macro, it's a net reduction to drop the definition of __HAVE_ARCH_PMD_WRITE. Link: http://lkml.kernel.org/r/151129126721.37405.13339850900081557813.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams <dan.j.williams@intel.com> Suggested-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Oliver OHalloran <oliveroh@au1.ibm.com> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-07mm: move phys_mem_access_prot_allowed() declaration to pgtable.hBaoyou Xie
We get 1 warning when building kernel with W=1: drivers/char/mem.c:220:12: warning: no previous prototype for 'phys_mem_access_prot_allowed' [-Wmissing-prototypes] int __weak phys_mem_access_prot_allowed(struct file *file, In fact, its declaration is spreading to several header files in different architecture, but need to be declare in common header file. So this patch moves phys_mem_access_prot_allowed() to pgtable.h. Link: http://lkml.kernel.org/r/1473751597-12139-1-git-send-email-baoyou.xie@linaro.org Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-04tree-wide: replace config_enabled() with IS_ENABLED()Masahiro Yamada
The use of config_enabled() against config options is ambiguous. In practical terms, config_enabled() is equivalent to IS_BUILTIN(), but the author might have used it for the meaning of IS_ENABLED(). Using IS_ENABLED(), IS_BUILTIN(), IS_MODULE() etc. makes the intention clearer. This commit replaces config_enabled() with IS_ENABLED() where possible. This commit is only touching bool config options. I noticed two cases where config_enabled() is used against a tristate option: - config_enabled(CONFIG_HWMON) [ drivers/net/wireless/ath/ath10k/thermal.c ] - config_enabled(CONFIG_BACKLIGHT_CLASS_DEVICE) [ drivers/gpu/drm/gma500/opregion.c ] I did not touch them because they should be converted to IS_BUILTIN() in order to keep the logic, but I was not sure it was the authors' intention. Link: http://lkml.kernel.org/r/1465215656-20569-1-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Stas Sergeev <stsp@list.ru> Cc: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Joshua Kinard <kumba@gentoo.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Borislav Petkov <bp@suse.de> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: "Dmitry V. Levin" <ldv@altlinux.org> Cc: yu-cheng yu <yu-cheng.yu@intel.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Brian Gerst <brgerst@gmail.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Will Drewry <wad@chromium.org> Cc: Nikolay Martynov <mar.kolya@gmail.com> Cc: Huacai Chen <chenhc@lemote.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> Cc: Rafal Milecki <zajec5@gmail.com> Cc: James Cowgill <James.Cowgill@imgtec.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Alex Smith <alex.smith@imgtec.com> Cc: Adam Buchbinder <adam.buchbinder@gmail.com> Cc: Qais Yousef <qais.yousef@imgtec.com> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Mikko Rapeli <mikko.rapeli@iki.fi> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Brian Norris <computersforpeace@gmail.com> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: "Luis R. Rodriguez" <mcgrof@do-not-panic.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Roland McGrath <roland@hack.frob.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Kalle Valo <kvalo@qca.qualcomm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Tony Wu <tung7970@gmail.com> Cc: Huaitong Han <huaitong.han@intel.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Juergen Gross <jgross@suse.com> Cc: Jason Cooper <jason@lakedaemon.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrea Gelmini <andrea.gelmini@gelma.net> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Rabin Vincent <rabin@rab.in> Cc: "Maciej W. Rozycki" <macro@imgtec.com> Cc: David Daney <david.daney@cavium.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-06MIPS: Fix page table corruption on THP permission changes.David Daney
When the core THP code is modifying the permissions of a huge page it calls pmd_modify(), which unfortunately was clearing the _PAGE_HUGE bit of the page table entry. The result can be kernel messages like: mm/memory.c:397: bad pmd 000000040080004d. mm/memory.c:397: bad pmd 00000003ff00004d. mm/memory.c:397: bad pmd 000000040100004d. or: ------------[ cut here ]------------ WARNING: at mm/mmap.c:3200 exit_mmap+0x150/0x158() Modules linked in: ipv6 at24 octeon3_ethernet octeon_srio_nexus m25p80 CPU: 12 PID: 1295 Comm: pmderr Not tainted 3.10.87-rt80-Cavium-Octeon #4 Stack : 0000000040808000 0000000014009ce1 0000000000400004 ffffffff81076ba0 0000000000000000 0000000000000000 ffffffff85110000 0000000000000119 0000000000000004 0000000000000000 0000000000000119 43617669756d2d4f 0000000000000000 ffffffff850fda40 ffffffff85110000 0000000000000000 0000000000000000 0000000000000009 ffffffff809207a0 0000000000000c80 ffffffff80f1bf20 0000000000000001 000000ffeca36828 0000000000000001 0000000000000000 0000000000000001 000000ffeca7e700 ffffffff80886924 80000003fd7a0000 80000003fd7a39b0 80000003fdea8000 ffffffff80885780 80000003fdea8000 ffffffff80f12218 000000000000000c 000000000000050f 0000000000000000 ffffffff80865c4c 0000000000000000 0000000000000000 ... Call Trace: [<ffffffff80865c4c>] show_stack+0x6c/0xf8 [<ffffffff80885780>] warn_slowpath_common+0x78/0xa8 [<ffffffff809207a0>] exit_mmap+0x150/0x158 [<ffffffff80882d44>] mmput+0x5c/0x110 [<ffffffff8088b450>] do_exit+0x230/0xa68 [<ffffffff8088be34>] do_group_exit+0x54/0x1d0 [<ffffffff8088bfc0>] __wake_up_parent+0x0/0x18 ---[ end trace c7b38293191c57dc ]--- BUG: Bad rss-counter state mm:80000003fa168000 idx:1 val:1536 Fix by not clearing _PAGE_HUGE bit. Signed-off-by: David Daney <david.daney@cavium.com> Tested-by: Aaro Koskinen <aaro.koskinen@nokia.com> Cc: stable@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/13687/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-07-02MIPS: Fix possible corruption of cache mode by mprotect.Ralf Baechle
The following testcase may result in a page table entries with a invalid CCA field being generated: static void *bindstack; static int sysrqfd; static void protect_low(int protect) { mprotect(bindstack, BINDSTACK_SIZE, protect); } static void sigbus_handler(int signal, siginfo_t * info, void *context) { void *addr = info->si_addr; write(sysrqfd, "x", 1); printf("sigbus, fault address %p (should not happen, but might)\n", addr); abort(); } static void run_bind_test(void) { unsigned int *p = bindstack; p[0] = 0xf001f001; write(sysrqfd, "x", 1); /* Set trap on access to p[0] */ protect_low(PROT_NONE); write(sysrqfd, "x", 1); /* Clear trap on access to p[0] */ protect_low(PROT_READ | PROT_WRITE | PROT_EXEC); write(sysrqfd, "x", 1); /* Check the contents of p[0] */ if (p[0] != 0xf001f001) { write(sysrqfd, "x", 1); /* Reached, but shouldn't be */ printf("badness, shouldn't happen but does\n"); abort(); } } int main(void) { struct sigaction sa; sysrqfd = open("/proc/sysrq-trigger", O_WRONLY); if (sigprocmask(SIG_BLOCK, NULL, &sa.sa_mask)) { perror("sigprocmask"); return 0; } sa.sa_sigaction = sigbus_handler; sa.sa_flags = SA_SIGINFO | SA_NODEFER | SA_RESTART; if (sigaction(SIGBUS, &sa, NULL)) { perror("sigaction"); return 0; } bindstack = mmap(NULL, BINDSTACK_SIZE, PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); if (bindstack == MAP_FAILED) { perror("mmap bindstack"); return 0; } printf("bindstack: %p\n", bindstack); run_bind_test(); printf("done\n"); return 0; } There are multiple ingredients for this: 1) PAGE_NONE is defined to _CACHE_CACHABLE_NONCOHERENT, which is CCA 3 on all platforms except SB1 where it's CCA 5. 2) _page_cachable_default must have bits set which are not set _CACHE_CACHABLE_NONCOHERENT. 3) Either the defective version of pte_modify for XPA or the standard version must be in used. However pte_modify for the 36 bit address space support is no affected. In that case additional bits in the final CCA mode may generate an invalid value for the CCA field. On the R10000 system where this was tracked down for example a CCA 7 has been observed, which is Uncached Accelerated. Fixed by: 1) Using the proper CCA mode for PAGE_NONE just like for all the other PAGE_* pte/pmd bits. 2) Fix the two affected variants of pte_modify. Further code inspection also shows the same issue to exist in pmd_modify which would affect huge page systems. Issue in pte_modify tracked down by Alastair Bridgewater, PAGE_NONE and pmd_modify issue found by me. The history of this goes back beyond Linus' git history. Chris Dearman's commit 351336929ccf222ae38ff0cb7a8dd5fd5c6236a0 ("[MIPS] Allow setting of the cache attribute at run time.") missed the opportunity to fix this but it was originally introduced in lmo commit d523832cf12007b3242e50bb77d0c9e63e0b6518 ("Missing from last commit.") and 32cc38229ac7538f2346918a09e75413e8861f87 ("New configuration option CONFIG_MIPS_UNCACHED.") Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Reported-by: Alastair Bridgewater <alastair.bridgewater@gmail.com>
2016-05-19Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge updates from Andrew Morton: - fsnotify fix - poll() timeout fix - a few scripts/ tweaks - debugobjects updates - the (small) ocfs2 queue - Minor fixes to kernel/padata.c - Maybe half of the MM queue * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (117 commits) mm, page_alloc: restore the original nodemask if the fast path allocation failed mm, page_alloc: uninline the bad page part of check_new_page() mm, page_alloc: don't duplicate code in free_pcp_prepare mm, page_alloc: defer debugging checks of pages allocated from the PCP mm, page_alloc: defer debugging checks of freed pages until a PCP drain cpuset: use static key better and convert to new API mm, page_alloc: inline pageblock lookup in page free fast paths mm, page_alloc: remove unnecessary variable from free_pcppages_bulk mm, page_alloc: pull out side effects from free_pages_check mm, page_alloc: un-inline the bad part of free_pages_check mm, page_alloc: check multiple page fields with a single branch mm, page_alloc: remove field from alloc_context mm, page_alloc: avoid looking up the first zone in a zonelist twice mm, page_alloc: shortcut watermark checks for order-0 pages mm, page_alloc: reduce cost of fair zone allocation policy retry mm, page_alloc: shorten the page allocator fast path mm, page_alloc: check once if a zone has isolated pageblocks mm, page_alloc: move __GFP_HARDWALL modifications out of the fastpath mm, page_alloc: simplify last cpupid reset mm, page_alloc: remove unnecessary initialisation from __alloc_pages_nodemask() ...
2016-05-19arch: fix has_transparent_hugepage()Hugh Dickins
I've just discovered that the useful-sounding has_transparent_hugepage() is actually an architecture-dependent minefield: on some arches it only builds if CONFIG_TRANSPARENT_HUGEPAGE=y, on others it's also there when not, but on some of those (arm and arm64) it then gives the wrong answer; and on mips alone it's marked __init, which would crash if called later (but so far it has not been called later). Straighten this out: make it available to all configs, with a sensible default in asm-generic/pgtable.h, removing its definitions from those arches (arc, arm, arm64, sparc, tile) which are served by the default, adding #define has_transparent_hugepage has_transparent_hugepage to those (mips, powerpc, s390, x86) which need to override the default at runtime, and removing the __init from mips (but maybe that kind of code should be avoided after init: set a static variable the first time it's called). Signed-off-by: Hugh Dickins <hughd@google.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andres Lagar-Cavilla <andreslc@google.com> Cc: Yang Shi <yang.shi@linaro.org> Cc: Ning Qu <quning@gmail.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Vineet Gupta <vgupta@synopsys.com> [arch/arc] Acked-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> [arch/s390] Acked-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-13MIPS: mm: Fix MIPS32 36b physical addressing (alchemy, netlogic)Paul Burton
There are 2 distinct cases in which a kernel for a MIPS32 CPU (CONFIG_CPU_MIPS32=y) may use 64 bit physical addresses (CONFIG_PHYS_ADDR_T_64BIT=y): - 36 bit physical addressing as used by RMI Alchemy & Netlogic XLP/XLR CPUs. - MIPS32r5 eXtended Physical Addressing (XPA). These 2 cases are distinct in that they require different behaviour from the kernel - the EntryLo registers have different formats. Until Linux v4.1 we only supported the first case, with code conditional upon the 2 aforementioned Kconfig variables being set. Commit c5b367835cfc ("MIPS: Add support for XPA.") added support for the second case, but did so by modifying the code that existed for the first case rather than treating the 2 cases as distinct. Since the EntryLo registers have different formats this breaks the 36 bit Alchemy/XLP/XLR case. Fix this by splitting the 2 cases, with XPA cases now being conditional upon CONFIG_XPA and the non-XPA case matching the code as it existed prior to commit c5b367835cfc ("MIPS: Add support for XPA."). Signed-off-by: Paul Burton <paul.burton@imgtec.com> Reported-by: Manuel Lauss <manuel.lauss@gmail.com> Tested-by: Manuel Lauss <manuel.lauss@gmail.com> Fixes: c5b367835cfc ("MIPS: Add support for XPA.") Cc: James Hogan <james.hogan@imgtec.com> Cc: David Daney <david.daney@cavium.com> Cc: Huacai Chen <chenhc@lemote.com> Cc: Maciej W. Rozycki <macro@linux-mips.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: David Hildenbrand <dahi@linux.vnet.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Alex Smith <alex.smith@imgtec.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: stable@vger.kernel.org # v4.1+ Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13119/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13MIPS: mm: Standardise on _PAGE_NO_READ, drop _PAGE_READPaul Burton
Ever since support for RI/XI was implemented by commit 6dd9344cfc41 ("MIPS: Implement Read Inhibit/eXecute Inhibit") we've had a mixture of _PAGE_READ & _PAGE_NO_READ bits. Rather than keep both around, switch away from using _PAGE_READ to determine page presence & instead invert the use to _PAGE_NO_READ. Wherever we formerly had no definition for _PAGE_NO_READ, change what was _PAGE_READ to _PAGE_NO_READ. The end result is that we consistently use _PAGE_NO_READ to determine whether a page is readable, regardless of whether RI/XI is implemented. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Reviewed-by: James Hogan <james.hogan@imgtec.com> Cc: David Daney <david.daney@cavium.com> Cc: Huacai Chen <chenhc@lemote.com> Cc: Maciej W. Rozycki <macro@linux-mips.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Alex Smith <alex.smith@imgtec.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/13116/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13MIPS: Loongson: Add Loongson-3A R2 basic supportHuacai Chen
Loongson-3 CPU family: Code-name Brand-name PRId Loongson-3A R1 Loongson-3A1000 0x6305 Loongson-3A R2 Loongson-3A2000 0x6308 Loongson-3B R1 Loongson-3B1000 0x6306 Loongson-3B R2 Loongson-3B1500 0x6307 Features of R2 revision of Loongson-3A: - Primary cache includes I-Cache, D-Cache and V-Cache (Victim Cache). - I-Cache, D-Cache and V-Cache are 16-way set-associative, linesize is 64 bytes. - 64 entries of VTLB (classic TLB), 1024 entries of FTLB (8-way set-associative). - Supports DSP/DSPv2 instructions, UserLocal register and Read-Inhibit/ Execute-Inhibit. [ralf@linux-mips.org: Resolved merge conflicts.] Signed-off-by: Huacai Chen <chenhc@lemote.com> Cc: Aurelien Jarno <aurelien@aurel32.net> Cc: Steven J . Hill <sjhill@realitydiluted.com> Cc: Fuxin Zhang <zhangfx@lemote.com> Cc: Zhangjin Wu <wuzhangjin@gmail.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/12751/ Patchwork: https://patchwork.linux-mips.org/patch/13136/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-13MIPS: Sync icache & dcache in set_pte_atPaul Burton
It's possible for pages to become visible prior to update_mmu_cache running if a thread within the same address space preempts the current thread or runs simultaneously on another CPU. That is, the following scenario is possible: CPU0 CPU1 write to page flush_dcache_page flush_icache_page set_pte_at map page update_mmu_cache If CPU1 maps the page in between CPU0's set_pte_at, which marks it valid & visible, and update_mmu_cache where the dcache flush occurs then CPU1s icache will fill from stale data (unless it fills from the dcache, in which case all is good, but most MIPS CPUs don't have this property). Commit 4d46a67a3eb8 ("MIPS: Fix race condition in lazy cache flushing.") attempted to fix that by performing the dcache flush in flush_icache_page such that it occurs before the set_pte_at call makes the page visible. However it has the problem that not all code that writes to pages exposed to userland call flush_icache_page. There are many callers of set_pte_at under mm/ and only 2 of them do call flush_icache_page. Thus the race window between a page becoming visible & being coherent between the icache & dcache remains open in some cases. To illustrate some of the cases, a WARN was added to __update_cache with this patch applied that triggered in cases where a page about to be flushed from the dcache was not the last page provided to flush_icache_page. That is, backtraces were obtained for cases in which the race window is left open without this patch. The 2 standout examples follow. When forking a process: [ 15.271842] [<80417630>] __update_cache+0xcc/0x188 [ 15.277274] [<80530394>] copy_page_range+0x56c/0x6ac [ 15.282861] [<8042936c>] copy_process.part.54+0xd40/0x17ac [ 15.289028] [<80429f80>] do_fork+0xe4/0x420 [ 15.293747] [<80413808>] handle_sys+0x128/0x14c When exec'ing an ELF binary: [ 14.445964] [<80417630>] __update_cache+0xcc/0x188 [ 14.451369] [<80538d88>] move_page_tables+0x414/0x498 [ 14.457075] [<8055d848>] setup_arg_pages+0x220/0x318 [ 14.462685] [<805b0f38>] load_elf_binary+0x530/0x12a0 [ 14.468374] [<8055ec3c>] search_binary_handler+0xbc/0x214 [ 14.474444] [<8055f6c0>] do_execveat_common+0x43c/0x67c [ 14.480324] [<8055f938>] do_execve+0x38/0x44 [ 14.485137] [<80413808>] handle_sys+0x128/0x14c These code paths write into a page, call flush_dcache_page then call set_pte_at without flush_icache_page inbetween. The end result is that the icache can become corrupted & userland processes may execute unexpected or invalid code, typically resulting in a reserved instruction exception, a trap or a segfault. Fix this race condition fully by performing any cache maintenance required to keep the icache & dcache in sync in set_pte_at, before the page is made valid. This has the added bonus of ensuring the cache maintenance always happens in one location, rather than being duplicated in flush_icache_page & update_mmu_cache. It also matches the way other architectures solve the same problem (see arm, ia64 & powerpc). Signed-off-by: Paul Burton <paul.burton@imgtec.com> Reported-by: Ionela Voinescu <ionela.voinescu@imgtec.com> Cc: Lars Persson <lars.persson@axis.com> Fixes: 4d46a67a3eb8 ("MIPS: Fix race condition in lazy cache flushing.") Cc: Steven J. Hill <sjhill@realitydiluted.com> Cc: David Daney <david.daney@cavium.com> Cc: Huacai Chen <chenhc@lemote.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Cc: stable <stable@vger.kernel.org> # v4.1+ Patchwork: https://patchwork.linux-mips.org/patch/12722/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-09MIPS: Adjust set_pte() SMP fix to handle R10000_LLSC_WARJoshua Kinard
Update the recent changes to set_pte() that were added in 46011e6ea392 to handle R10000_LLSC_WAR, and format the assembly to match other areas of the MIPS tree using the same WAR. This also incorporates a patch recently sent in my Markos Chandras, "Remove local LL/SC preprocessor variants", so that patch doesn't need to be applied if this one is accepted. Signed-off-by: Joshua Kinard <kumba@gentoo.org> Fixes: 46011e6ea392 ("MIPS: Make set_pte() SMP safe.) Cc: David Daney <david.daney@cavium.com> Cc: Linux/MIPS <linux-mips@linux-mips.org> Patchwork: https://patchwork.linux-mips.org/patch/11103/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-05-09MIPS: Move definitions for 32/64-bit agonstic inline assembler to new file.Ralf Baechle
Inspired by Markos Chandras' patch. I just didn't want do pull bitsops.h into pgtable.h. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> References: https://patchwork.linux-mips.org/patch/11052/
2016-01-24Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linusLinus Torvalds
Pull MIPS updates from Ralf Baechle: "This is the main pull request for MIPS for 4.5 plus some 4.4 fixes. The executive summary: - ATH79 platform improvments, use DT bindings for the ATH79 USB PHY. - Avoid useless rebuilds for zboot. - jz4780: Add NEMC, BCH and NAND device tree nodes - Initial support for the MicroChip's DT platform. As all the device drivers are missing this is still of limited use. - Some Loongson3 cleanups. - The unavoidable whitespace polishing. - Reduce clock skew when synchronizing the CPU cycle counters on CPU startup. - Add MIPS R6 fixes. - Lots of cleanups across arch/mips as fallout from KVM. - Lots of minor fixes and changes for IEEE 754-2008 support to the FPU emulator / fp-assist software. - Minor Ralink, BCM47xx and bcm963xx platform support improvments. - Support SMP on BCM63168" * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (84 commits) MIPS: zboot: Add support for serial debug using the PROM MIPS: zboot: Avoid useless rebuilds MIPS: BMIPS: Enable ARCH_WANT_OPTIONAL_GPIOLIB MIPS: bcm63xx: nvram: Remove unused bcm63xx_nvram_get_psi_size() function MIPS: bcm963xx: Update bcm_tag field image_sequence MIPS: bcm963xx: Move extended flash address to bcm_tag header file MIPS: bcm963xx: Move Broadcom BCM963xx image tag data structure MIPS: bcm63xx: nvram: Use nvram structure definition from header file MIPS: bcm963xx: Add Broadcom BCM963xx board nvram data structure MAINTAINERS: Add KVM for MIPS entry MIPS: KVM: Add missing newline to kvm_err() MIPS: Move KVM specific opcodes into asm/inst.h MIPS: KVM: Use cacheops.h definitions MIPS: Break down cacheops.h definitions MIPS: Use EXCCODE_ constants with set_except_vector() MIPS: Update trap codes MIPS: Move Cause.ExcCode trap codes to mipsregs.h MIPS: KVM: Make kvm_mips_{init,exit}() static MIPS: KVM: Refactor added offsetof()s MIPS: KVM: Convert EXPORT_SYMBOL to _GPL ...
2016-01-24MIPS: Fix some missing CONFIG_CPU_MIPSR6 #ifdefsHuacai Chen
Commit be0c37c985eddc4 (MIPS: Rearrange PTE bits into fixed positions.) defines fixed PTE bits for MIPS R2. Then, commit d7b631419b3d230a4d383 (MIPS: pgtable-bits: Fix XPA damage to R6 definitions.) adds the MIPS R6 definitions in the same way as MIPS R2. But some R6 #ifdefs in the later commit are missing, so in this patch I fix that. Signed-off-by: Huacai Chen <chenhc@lemote.com> Cc: Aurelien Jarno <aurelien@aurel32.net> Cc: Steven J. Hill <Steven.Hill@imgtec.com> Cc: Fuxin Zhang <zhangfx@lemote.com> Cc: Zhangjin Wu <wuzhangjin@gmail.com> Cc: linux-mips@linux-mips.org Cc: stable@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/12164/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2016-01-15mips, thp: remove infrastructure for handling splitting PMDsKirill A. Shutemov
With new refcounting we don't need to mark PMDs splitting. Let's drop code to handle this. pmdp_splitting_flush() is not needed too: on splitting PMD we will do pmdp_clear_flush() + set_pte_at(). pmdp_clear_flush() will do IPI as needed for fast_gup. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Steve Capper <steve.capper@linaro.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-03MIPS: Fix definition of pgprot_writecombine()Alex Smith
If pgprot_writecombine is not #defined, asm-generic/pgtable.h will try to provide a default implementation by #defining it to pgprot_noncached. However our implementation is an inline function rather than a #define, so it was never actually used because of the #define in generic code. Add "#define pgprot_writecombine pgprot_writecombine" to prevent generic code from re-defining it. Signed-off-by: Alex Smith <alex.smith@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10767/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-08-05MIPS: Make set_pte() SMP safe.David Daney
On MIPS the GLOBAL bit of the PTE must have the same value in any aligned pair of PTEs. These pairs of PTEs are referred to as "buddies". In a SMP system is is possible for two CPUs to be calling set_pte() on adjacent PTEs at the same time. There is a race between setting the PTE and a different CPU setting the GLOBAL bit in its buddy PTE. This race can be observed when multiple CPUs are executing vmap()/vfree() at the same time. Make setting the buddy PTE's GLOBAL bit an atomic operation to close the race condition. The case of CONFIG_64BIT_PHYS_ADDR && CONFIG_CPU_MIPS32 is *not* handled. Signed-off-by: David Daney <david.daney@cavium.com> Cc: <stable@vger.kernel.org> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10835/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-06-24mm: clarify that the function operates on hugepage pteAneesh Kumar K.V
We have confusing functions to clear pmd, pmd_clear_* and pmd_clear. Add _huge_ to pmdp_clear functions so that we are clear that they operate on hugepage pte. We don't bother about other functions like pmdp_set_wrprotect, pmdp_clear_flush_young, because they operate on PTE bits and hence indicate they are operating on hugepage ptes Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-03-25Revert "MIPS: Remove race window in page fault handling"Lars Persson
Revert commit 2a4a8b1e5d9d ("MIPS: Remove race window in page fault handling") because it increased the number of flushed dcache pages and became a performance problem for some workloads. Signed-off-by: Lars Persson <larper@axis.com> Cc: linux-mips@linux-mips.org Cc: paul.burton@imgtec.com Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/9345/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-19MIPS: Add support for XPA.Steven J. Hill
Add support for extended physical addressing (XPA) so that 32-bit platforms can access equal to or greater than 40 bits of physical addresses. NOTE: 1) XPA and EVA are not the same and cannot be used simultaneously. 2) If you configure your kernel for XPA, the PTEs and all address sizes become 64-bit. 3) Your platform MUST have working HIGHMEM support. Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9355/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-18MIPS: Rearrange PTE bits into fixed positions.Steven J. Hill
This patch rearranges the PTE bits into fixed positions for R2 and later cores. In the past, the TLB handling code did runtime checking of RI/XI and adjusted the shifts and rotates in order to fit the largest PFN value into the PTE. The checking now occurs when building the TLB handler, thus eliminating those checks. These new arrangements also define the largest possible PFN value that can fit in the PTE. HUGE page support is only available for 64-bit cores. Layouts of the PTE bits are now: 64-bit, R1 or earlier: CCC D V G [S H] M A W R P 32-bit, R1 or earler: CCC D V G M A W R P 64-bit, R2 or later: CCC D V G RI/R XI [S H] M A W P 32-bit, R2 or later: CCC D V G RI/R XI M A W P [ralf@linux-mips.org: Fix another build error *rant* *rant*] Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9353/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-21Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linusLinus Torvalds
Pull MIPS updates from Ralf Baechle: "This is the main pull request for MIPS: - a number of fixes that didn't make the 3.19 release. - a number of cleanups. - preliminary support for Cavium's Octeon 3 SOCs which feature up to 48 MIPS64 R3 cores with FPU and hardware virtualization. - support for MIPS R6 processors. Revision 6 of the MIPS architecture is a major revision of the MIPS architecture which does away with many of original sins of the architecture such as branch delay slots. This and other changes in R6 require major changes throughout the entire MIPS core architecture code and make up for the lion share of this pull request. - finally some preparatory work for eXtendend Physical Address support, which allows support of up to 40 bit of physical address space on 32 bit processors" [ Ahh, MIPS can't leave the PAE brain damage alone. It's like every CPU architect has to make that mistake, but pee in the snow by changing the TLA. But whether it's called PAE, LPAE or XPA, it's horrid crud - Linus ] * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (114 commits) MIPS: sead3: Corrected get_c0_perfcount_int MIPS: mm: Remove dead macro definitions MIPS: OCTEON: irq: add CIB and other fixes MIPS: OCTEON: Don't do acknowledge operations for level triggered irqs. MIPS: OCTEON: More OCTEONIII support MIPS: OCTEON: Remove setting of processor specific CVMCTL icache bits. MIPS: OCTEON: Core-15169 Workaround and general CVMSEG cleanup. MIPS: OCTEON: Update octeon-model.h code for new SoCs. MIPS: OCTEON: Implement DCache errata workaround for all CN6XXX MIPS: OCTEON: Add little-endian support to asm/octeon/octeon.h MIPS: OCTEON: Implement the core-16057 workaround MIPS: OCTEON: Delete unused COP2 saving code MIPS: OCTEON: Use correct instruction to read 64-bit COP0 register MIPS: OCTEON: Save and restore CP2 SHA3 state MIPS: OCTEON: Fix FP context save. MIPS: OCTEON: Save/Restore wider multiply registers in OCTEON III CPUs MIPS: boot: Provide more uImage options MIPS: Remove unneeded #ifdef __KERNEL__ from asm/processor.h MIPS: ip22-gio: Remove legacy suspend/resume support mips: pci: Add ifdef around pci_proc_domain ...
2015-02-19MIPS: Usage and cosmetic cleanups of page table bits.Steven J. Hill
* Clean up white spaces and tabs. * Get rid of remaining hardcoded values for calculating shifts and masks. * Get rid of redundant macro values. * Do not use page table bits directly in #ifdef's. Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9287/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-16MIPS: HTW: Prevent accidental HTW start due to nested htw_{start, stop}Markos Chandras
activate_mm() and switch_mm() call get_new_mmu_context() which in turn can enable the HTW before the entryhi is changed with the new ASID. Since the latter will enable the HTW in local_flush_tlb_all(), then there is a small timing window where the HTW is running with the new ASID but with an old pgd since the TLBMISS_HANDLER_SETUP_PGD hasn't assigned a new one yet. In order to prevent that, we introduce a simple htw counter to avoid starting HTW accidentally due to nested htw_{start,stop}() sequences. Moreover, since various IPI calls can enforce TLB flushing operations on a different core, such an operation may interrupt another htw_{stop,start} in progress leading inconsistent updates of the htw_seq variable. In order to avoid that, we disable the interrupts whenever we update that variable. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: <stable@vger.kernel.org> # 3.17+ Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9118/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-16MIPS: asm: pgtable: Prevent HTW race when updating PTEsMarkos Chandras
Whenever we modify a page table entry, we need to ensure that the HTW will not fetch a stable entry. And for that to happen we need to ensure that HTW is stopped before we modify the said entry otherwise the HTW may already be in the process of reading that entry and fetching the old information. As a result of which, we replace the htw_reset() calls with htw_{stop,start} in more appropriate places. This also removes the remaining users of htw_reset() and as a result we drop that macro Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: <stable@vger.kernel.org> # 3.17+ Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9116/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-16MIPS: asm: pgtable: Add c0 hazards on HTW start/stop sequencesMarkos Chandras
When we use htw_{start,stop}() outside of htw_reset(), we need to ensure that c0 changes have been propagated properly before we attempt to continue with subsequence memory operations. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: <stable@vger.kernel.org> # 3.17+ Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/9114/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-02-10mips: drop _PAGE_FILE and pte_file()-related helpersKirill A. Shutemov
We've replaced remap_file_pages(2) implementation with emulation. Nobody creates non-linear mapping anymore. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-11-24MIPS: Cosmetic cleanups of page table headers.Steven J. Hill
* Clean up white spaces and tabs. * Remove _PAGE_R4KBUG which is no longer used. * Get rid of hardcoded values and calculate shifts and masks where possible. Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/8457/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24MIPS: Replace use of phys_t with phys_addr_t.Ralf Baechle
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-11-24MIPS: Replace MIPS-specific 64BIT_PHYS_ADDR with generic PHYS_ADDR_T_64BITRalf Baechle
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-09-22MIPS: pgtable.h: Implement the pgprot_writecombine function for MIPSMarkos Chandras
Previously, the pgprot_writecombine function was simply defined as pgprot_uncached in include/asm-generic/pgtable.h. This is not optimal for cores that can actually do write-combine memory writes so define this function to take into account the core's cache coherency attribute to achieve such behavior. Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/7403/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-08-19MIPS: Remove race window in page fault handlingLars Persson
Multicore MIPSes without I/D hardware coherency suffered from a race condition in the page fault handler. The page table entry was published before any pending lazy D-cache flush was committed, hence it allowed execution of stale page cache data by other VPEs in the system. To make the cache handling safe we need to perform flushing already in the set_pte_at function. MIPSes without coherent I-caches can get a small increase in flushes due to the unavailability of the execute flag in set_pte_at. [ralf@linux-mips.org: outlining set_pte_at() saves a good k in a test build, so I moved its definition from pgtable.h to cache.c.] Signed-off-by: Lars Persson <larper@axis.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/7511/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-08-02MIPS: mm: Use the Hardware Page Table Walker if the core supports itMarkos Chandras
The Hardware Page Table Walker aims to speed up TLB refill exceptions by handling them in the hardware level instead of having a software TLB refill handler. However, a TLB refill exception can still be thrown in certain cases such as, synchronus exceptions, or address translation or memory errors during the HTW operation. As a result of which, HTW must not be considered a complete replacement for the TLB refill software handler, but rather a fast-path for it. For HTW to work, the PWBase register must contain the task's page global directory address so the HTW will kick in on TLB refill exceptions. Due to HTW being a separate engine embedded deep in the CPU pipeline, we need to restart the HTW everytime a PTE changes to avoid HTW fetching a old entry from the page tables. It's also necessary to restart the HTW on context switches to prevent it from fetching a page from the previous process. Finally, since HTW is using the entryhi register to write the translations to the TLB, it's necessary to stop the HTW whenever the entryhi changes (eg for tlb probe perations) and enable it back afterwards. == Performance == The following trivial test was used to measure the performance of the HTW. Using the same root filesystem, the following command was used to measure the number of tlb refill handler executions with and without (using 'nohtw' kernel parameter) HTW support. The kernel was modified to use a scratch register as a counter for the TLB refill exceptions. find /usr -type f -exec ls -lh {} \; HTW Enabled: TLB refill exceptions: 12306 HTW Disabled: TLB refill exceptions: 17805 Signed-off-by: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-mips@linux-mips.org Cc: Markos Chandras <markos.chandras@imgtec.com> Patchwork: https://patchwork.linux-mips.org/patch/7336/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-05-28MIPS: add kmap_noncoherent to wire a cached non-coherent TLB entryPaul Burton
This is identical to kmap_coherent apart from the cache coherency attribute used for the TLB entry, so kmap_coherent is abstracted to kmap_prot which is then called for both kmap_coherent & kmap_noncoherent. This will be used by a subsequent patch. Suggested-by: Leonid Yegoshin <leonid.yegoshin@imgtec.com> Signed-off-by: Paul Burton <paul.burton@imgtec.com>
2013-06-29consolidate io_remap_pfn_range definitionsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-04-08MIPS: Add linux/mm_types.h to pgtable.hCorey Minyard
With the addition of transparent huge pages, pgtable.h uses struct page. However, it is possible to include pgtable.h without anything defining struct page. So add the include to get it. Signed-off-by: Corey Minyard <cminyard@mvista.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-02-01MIPS: Whitespace cleanup.Ralf Baechle
Having received another series of whitespace patches I decided to do this once and for all rather than dealing with this kind of patches trickling in forever. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2012-12-14Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linusLinus Torvalds
Pull MIPS updates from Ralf Baechle: "The MIPS bits for 3.8. This also includes a bunch fixes that were sitting in the linux-mips.org git tree for a long time. This pull request contains updates to several OCTEON drivers and the board support code for BCM47XX, BCM63XX, XLP, XLR, XLS, lantiq, Loongson1B, updates to the SSB bus support, MIPS kexec code and adds support for kdump. When pulling this, there are two expected merge conflicts in include/linux/bcma/bcma_driver_chipcommon.h which are trivial to resolve, just remove the conflict markers and keep both alternatives." * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (90 commits) MIPS: PMC-Sierra Yosemite: Remove support. VIDEO: Newport Fix console crashes MIPS: wrppmc: Fix build of PCI code. MIPS: IP22/IP28: Fix build of EISA code. MIPS: RB532: Fix build of prom code. MIPS: PowerTV: Fix build. MIPS: IP27: Correct fucked grammar in ops-bridge.c MIPS: Highmem: Fix build error if CONFIG_DEBUG_HIGHMEM is disabled MIPS: Fix potencial corruption MIPS: Fix for warning from FPU emulation code MIPS: Handle COP3 Unusable exception as COP1X for FP emulation MIPS: Fix poweroff failure when HOTPLUG_CPU configured. MIPS: MT: Fix build with CONFIG_UIDGID_STRICT_TYPE_CHECKS=y MIPS: Remove unused smvp.h MIPS/EDAC: Improve OCTEON EDAC support. MIPS: OCTEON: Add definitions for OCTEON memory contoller registers. MIPS: OCTEON: Add OCTEON family definitions to octeon-model.h ata: pata_octeon_cf: Use correct byte order for DMA in when built little-endian. MIPS/OCTEON/ata: Convert pata_octeon_cf.c to use device tree. MIPS: Remove usage of CEVT_R4K_LIB config option. ...
2012-12-12asm-generic, mm: pgtable: consolidate zero page helpersKirill A. Shutemov
We have two different implementation of is_zero_pfn() and my_zero_pfn() helpers: for architectures with and without zero page coloring. Let's consolidate them in <asm-generic/pgtable.h>. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-12MIPS: Transparent Huge Pages supportRalf Baechle
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>