summaryrefslogtreecommitdiffstats
path: root/arch
Commit message (Collapse)AuthorAgeFilesLines
* ARM: convert arm/arm64 arch timer to use CLKSRC_OF initRob Herring2013-04-1116-67/+19
| | | | | | | | | | | | | | | | | | | | | | | | This converts arm and arm64 to use CLKSRC_OF DT based initialization for the arch timer. A new function arch_timer_arch_init is added to allow for arch specific setup. This has a side effect of enabling sched_clock on omap5 and exynos5. There should not be any reason not to use the arch timers for sched_clock. Signed-off-by: Rob Herring <rob.herring@calxeda.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Kukjin Kim <kgene.kim@samsung.com> Cc: Tony Lindgren <tony@atomide.com> Cc: Simon Horman <horms@verge.net.au> Cc: Magnus Damm <magnus.damm@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-samsung-soc@vger.kernel.org Cc: linux-omap@vger.kernel.org Cc: linux-sh@vger.kernel.org Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
* ARM: make machine_desc->init_time default to clocksource_of_initArnd Bergmann2013-04-111-1/+6
| | | | | | | | | | | | Originally from a default machine descriptor patch from Arnd, pull out just the default call to clocksource_of_init part. This is needed so that platforms can simply remove .init_time calls as they are converted to use clocksource_of_init. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Signed-off-by: Rob Herring <rob.herring@calxeda.com>
* ARM: arch_timer: use full 64-bit counter for sched_clockRob Herring2013-04-111-5/+13
| | | | | | | | | Only 32-bits of the arch timer were being used and wrapping was needlessly being done in s/w. By using the full counter (56-64 bits), we don't need to deal with wrapping and can simplify the implementation when using arch timer. Signed-off-by: Rob Herring <rob.herring@calxeda.com>
* ARM: make sched_clock just call a function pointerRob Herring2013-04-102-1/+10
| | | | | | | | This converts sched_clock to simply a call to a function pointer in order to allow overriding it. This will allow for use with 64-bit counters where overflow handling is not needed. Signed-off-by: Rob Herring <rob.herring@calxeda.com>
* ARM: sched_clock: allow changing to higher frequency counterRob Herring2013-04-101-1/+5
| | | | | | | Allow multiple calls to setup_sched_clock and switch to the new counter if it is higher frequency. Signed-off-by: Rob Herring <rob.herring@calxeda.com>
* ARM: smp_twd: convert to use CLKSRC_OF initRob Herring2013-03-119-34/+17
| | | | | | | | | | | | | | | | | | | | | | Now that we have OF based init with CLKSRC_OF, convert smp_twd init function to use it and covert all callers of twd_local_timer_of_register. Signed-off-by: Rob Herring <rob.herring@calxeda.com> Cc: Shawn Guo <shawn.guo@linaro.org> Cc: Sascha Hauer <kernel@pengutronix.de> Cc: Russell King <linux@arm.linux.org.uk> Cc: Viresh Kumar <viresh.linux@gmail.com> Cc: Shiraz Hashim <shiraz.hashim@st.com> Cc: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com> Cc: John Stultz <johnstul@us.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-omap@vger.kernel.org Cc: spear-devel@list.st.com Reviewed-by: Stephen Warren <swarren@nvidia.com> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Linus Walleij <linus.walleij@linaro.org>
* Merge branch 'for-linus' of ↵Linus Torvalds2013-03-093-0/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull namespace bugfixes from Eric Biederman: "This is three simple fixes against 3.9-rc1. I have tested each of these fixes and verified they work correctly. The userns oops in key_change_session_keyring and the BUG_ON triggered by proc_ns_follow_link were found by Dave Jones. I am including the enhancement for mount to only trigger requests of filesystem modules here instead of delaying this for the 3.10 merge window because it is both trivial and the kind of change that tends to bit-rot if left untouched for two months." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: proc: Use nd_jump_link in proc_ns_follow_link fs: Limit sys_mount to only request filesystem modules (Part 2). fs: Limit sys_mount to only request filesystem modules. userns: Stop oopsing in key_change_session_keyring
| * fs: Limit sys_mount to only request filesystem modules.Eric W. Biederman2013-03-033-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Modify the request_module to prefix the file system type with "fs-" and add aliases to all of the filesystems that can be built as modules to match. A common practice is to build all of the kernel code and leave code that is not commonly needed as modules, with the result that many users are exposed to any bug anywhere in the kernel. Looking for filesystems with a fs- prefix limits the pool of possible modules that can be loaded by mount to just filesystems trivially making things safer with no real cost. Using aliases means user space can control the policy of which filesystem modules are auto-loaded by editing /etc/modprobe.d/*.conf with blacklist and alias directives. Allowing simple, safe, well understood work-arounds to known problematic software. This also addresses a rare but unfortunate problem where the filesystem name is not the same as it's module name and module auto-loading would not work. While writing this patch I saw a handful of such cases. The most significant being autofs that lives in the module autofs4. This is relevant to user namespaces because we can reach the request module in get_fs_type() without having any special permissions, and people get uncomfortable when a user specified string (in this case the filesystem type) goes all of the way to request_module. After having looked at this issue I don't think there is any particular reason to perform any filtering or permission checks beyond making it clear in the module request that we want a filesystem module. The common pattern in the kernel is to call request_module() without regards to the users permissions. In general all a filesystem module does once loaded is call register_filesystem() and go to sleep. Which means there is not much attack surface exposed by loading a filesytem module unless the filesystem is mounted. In a user namespace filesystems are not mounted unless .fs_flags = FS_USERNS_MOUNT, which most filesystems do not set today. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Acked-by: Kees Cook <keescook@chromium.org> Reported-by: Kees Cook <keescook@google.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* | Merge branch 'akpm' (fixes from Andrew)Linus Torvalds2013-03-081-0/+1
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge misc fixes from Andrew Morton. * emailed patches from Andrew Morton <akpm@linux-foundation.org>: alpha: boot: fix build breakage introduced by system.h disintegration memcg: initialize kmem-cache destroying work earlier Randy has moved ksm: fix m68k build: only NUMA needs pfn_to_nid dmi_scan: fix missing check for _DMI_ signature in smbios_present() Revert parts of "hlist: drop the node parameter from iterators" idr: remove WARN_ON_ONCE() on negative IDs mm/mempolicy.c: fix sp_node_init() argument ordering mm/mempolicy.c: fix wrong sp_node insertion ipc: don't allocate a copy larger than max ipc: fix potential oops when src msg > 4k w/ MSG_COPY
| * | alpha: boot: fix build breakage introduced by system.h disintegrationWill Deacon2013-03-081-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit ec2212088c42 ("Disintegrate asm/system.h for Alpha") removed the system.h include from boot/head.S, which puts the PAL_* asm constants out of scope. Include <asm/pal.h> so we can get building again. Signed-off-by: Will Deacon <will.deacon@arm.com> Cc: David Rusling <david.rusling@linaro.org> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge branch 'stable' of ↵Linus Torvalds2013-03-082-13/+32
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile Pull tile architecture fixes from Chris Metcalf: "This fixes the bug that Al Viro spotted with the compat llseek code. I also fixed the compat syscall definitions to use the new syscall define macros to properly sign-extend their arguments." * 'stable' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile: tile: properly use COMPAT_SYSCALL_DEFINEx tile: work around bug in the generic sys_llseek
| * | | tile: properly use COMPAT_SYSCALL_DEFINExChris Metcalf2013-03-041-16/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This was pointed out by Al Viro. Using the correct wrappers properly does sign extension as necessary on syscall arguments. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
| * | | tile: work around bug in the generic sys_llseekChris Metcalf2013-03-042-0/+16
| | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | sys_llseek should specify the high and low 32-bit seek values as "unsigned int" but instead it specifies "unsigned long". Since compat syscall arguments are always sign-extended on tile, this means that a seek value of 0xffffffff will be incorrectly interpreted as a value of -1ULL. To avoid the risk of breaking binary compatibility on architectures that already use sys_llseek this way, we follow the same path as MIPS and provide a wrapper override. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> Cc: stable@kernel.org [v3.6 onwards]
* | | Merge tag 'metag-for-v3.9-rc2' of ↵Linus Torvalds2013-03-082-3/+1
|\ \ \ | |_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag Pull metag bugfixes from James Hogan: "A couple of fairly minor arch/metag integration fixes from v3.9-rc1: - remove SET_PERSONALITY(): use default definition like other arches now do. - inhibit NUMA balancing: like SH, NUMA is used for memories with different latencies. ARCH_WANT_VARIABLE_LOCALITY has been added for this purpose." * tag 'metag-for-v3.9-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/metag: metag: Inhibit NUMA balancing. metag: remove SET_PERSONALITY()
| * | metag: Inhibit NUMA balancing.Paul Mundt2013-03-041-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | The metag NUMA implementation follows the SH model, using different nodes for memories with different latencies. As such, we ensure that automated balancing between nodes is inhibited, by way of the new ARCH_WANT_VARIABLE_LOCALITY. Signed-off-by: Paul Mundt <lethal@linux-sh.org> Signed-off-by: James Hogan <james.hogan@imgtec.com>
| * | metag: remove SET_PERSONALITY()James Hogan2013-03-041-3/+0
| |/ | | | | | | | | | | | | | | | | | | | | Commit e72837e3e7bae3f182c4ac63c9424e86f1158dd0 ("default SET_PERSONALITY() in linux/elf.h"). The above commit moved the common definition of SET_PERSONALITY() in a bunch of the arch headers to linux/elf.h. Metag shares that common definition so remove it from arch/metag/include/asm/elf.h too. Signed-off-by: James Hogan <james.hogan@imgtec.com>
* | Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds2013-03-075-9/+36
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Peter Anvin: "Several boot fixes (MacBook, legacy EFI bootloaders), another please-don't-brick fix, and some minor stuff." * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86: Do not try to sync identity map for non-mapped pages x86, doc: Be explicit about what the x86 struct boot_params requires x86: Don't clear efi_info even if the sentinel hits x86, mm: Make sure to find a 2M free block for the first mapped area x86: Fix 32-bit *_cpu_data initializers efivarfs: return accurate error code in efivarfs_fill_super() efivars: efivarfs_valid_name() should handle pstore syntax efi: be more paranoid about available space when creating variables iommu, x86: Add DMA remap fault reason x86, smpboot: Remove unused variable
| * | x86: Do not try to sync identity map for non-mapped pagesDave Hansen2013-03-071-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kernel_map_sync_memtype() is called from a variety of contexts. The pat.c code that calls it seems to ensure that it is not called for non-ram areas by checking via pat_pagerange_is_ram(). It is important that it only be called on the actual identity map because there *IS* no map to sync for highmem pages, or for memory holes. The ioremap.c uses are not as careful as those from pat.c, and call kernel_map_sync_memtype() on PCI space which is in the middle of the kernel identity map _range_, but is not actually mapped. This patch adds a check to kernel_map_sync_memtype() which probably duplicates some of the checks already in pat.c. But, it is necessary for the ioremap.c uses and shouldn't hurt other callers. I have reproduced this bug and this patch fixes it for me and the original bug reporter: https://lkml.org/lkml/2013/2/5/396 Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Link: http://lkml.kernel.org/r/20130307163151.D9B58C4E@kernel.stglabs.ibm.com Signed-off-by: Dave Hansen <dave@sr71.net> Tested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| * | x86, doc: Be explicit about what the x86 struct boot_params requiresPeter Jones2013-03-061-1/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the sentinel triggers, we do not want the boot loader authors to just poke it and make the error go away, we want them to actually fix the problem. This should help avoid making the incorrect change in non-compliant bootloaders. [ hpa: dropped the Documentation/x86/boot.txt hunk pending clarifications ] Signed-off-by: Peter Jones <pjones@redhat.com> Link: http://lkml.kernel.org/r/1362592823-28967-1-git-send-email-pjones@redhat.com Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| * | x86: Don't clear efi_info even if the sentinel hitsJosh Boyer2013-03-061-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When boot_params->sentinel is set, all we really know is that some undefined set of fields in struct boot_params contain garbage. In the particular case of efi_info, however, there is a private magic for that substructure, so it is generally safe to leave it even if the bootloader is broken. kexec (for which we did the initial analysis) did not initialize this field, but of course all the EFI bootloaders do, and most EFI bootloaders are broken in this respect (and should be fixed.) Reported-by: Robin Holt <holt@sgi.com> Link: http://lkml.kernel.org/r/CA%2B5PVA51-FT14p4CRYKbicykugVb=PiaEycdQ57CK2km_OQuRQ@mail.gmail.com Tested-by: Josh Boyer <jwboyer@gmail.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| * | x86, mm: Make sure to find a 2M free block for the first mapped areaYinghai Lu2013-03-061-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Henrik reported that his MacAir 3.1 would not boot with | commit 8d57470d8f859635deffe3919d7d4867b488b85a | Date: Fri Nov 16 19:38:58 2012 -0800 | | x86, mm: setup page table in top-down It turns out that we do not calculate the real_end properly: We try to get 2M size with 4K alignment, and later will round down to 2M, so we will get less then 2M for first mapping, in extreme case could be only 4K only. In Henrik's system it has (1M-32K) as last usable rage is [mem 0x7f9db000-0x7fef8fff]. The problem is exposed when EFI booting have several holes and it will force mapping to use PTE instead as we only map usable areas. To fix it, just make it be 2M aligned, so we can be guaranteed to be able to use large pages to map it. Reported-by: Henrik Rydberg <rydberg@euromail.se> Bisected-by: Henrik Rydberg <rydberg@euromail.se> Tested-by: Henrik Rydberg <rydberg@euromail.se> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Link: http://lkml.kernel.org/r/CAE9FiQX4nQ7_1kg5RL_vh56rmcSHXUi1ExrZX7CwED4NGMnHfg@mail.gmail.com Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| * | x86: Fix 32-bit *_cpu_data initializersKrzysztof Mazur2013-03-061-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The commit 27be457000211a6903968dfce06d5f73f051a217 ('x86 idle: remove 32-bit-only "no-hlt" parameter, hlt_works_ok flag') removed the hlt_works_ok flag from struct cpuinfo_x86, but boot_cpu_data and new_cpu_data initializers were not changed causing setting f00f_bug flag, instead of fdiv_bug. If CONFIG_X86_F00F_BUG is not set the f00f_bug flag is never cleared. To avoid such problems in future C99-style initialization is now used. Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net> Acked-by: Borislav Petkov <bp@suse.de> Cc: len.brown@intel.com Link: http://lkml.kernel.org/r/1362266082-2227-1-git-send-email-krzysiek@podlesie.net Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
| * | x86, smpboot: Remove unused variableBorislav Petkov2013-03-051-2/+1
| |/ | | | | | | | | | | | | | | | | | | | | | | | | The cpuinfo_x86 ptr is unused now. Drop it. Got obsolete by 69fb3676df33 ("x86 idle: remove mwait_idle() and "idle=mwait" cmdline param") removing its only user. [ hpa: fixes gcc warning ] Signed-off-by: Borislav Petkov <bp@suse.de> Link: http://lkml.kernel.org/r/1362428180-8865-2-git-send-email-bp@alien8.de Cc: Len Brown <len.brown@intel.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
* | Merge branch 'fixes' of git://git.linaro.org/people/rmk/linux-armLinus Torvalds2013-03-0721-109/+178
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull ARM fixes from Russell King: "Mainly a group of fixes, the only exception is the wiring up of the kcmp syscall now that those patches went in during the last merge window." * 'fixes' of git://git.linaro.org/people/rmk/linux-arm: ARM: 7668/1: fix memset-related crashes caused by recent GCC (4.7.2) optimizations ARM: 7667/1: perf: Fix section mismatch on armpmu_init() ARM: 7666/1: decompressor: add -mno-single-pic-base for building the decompressor ARM: 7665/1: Wire up kcmp syscall ARM: 7664/1: perf: remove erroneous semicolon from event initialisation ARM: 7663/1: perf: fix ARMv7 EVTYPE_MASK to include NSH bit ARM: 7662/1: hw_breakpoint: reset debug logic on secondary CPUs in s2ram resume ARM: 7661/1: mm: perform explicit branch predictor maintenance when required ARM: 7660/1: tlb: add branch predictor maintenance operations ARM: 7659/1: mm: make mm->context.id an atomic64_t variable ARM: 7658/1: mm: fix race updating mm->context.id on ASID rollover ARM: 7657/1: head: fix swapper and idmap population with LPAE and big-endian ARM: 7655/1: smp_twd: make twd_local_timer_of_register() no-op for nosmp ARM: 7652/1: mm: fix missing use of 'asid' to get asid value from mm->context.id ARM: 7642/1: netx: bump IRQ offset to 64
| * | ARM: 7668/1: fix memset-related crashes caused by recent GCC (4.7.2) ↵Ivan Djelic2013-03-071-41/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | optimizations Recent GCC versions (e.g. GCC-4.7.2) perform optimizations based on assumptions about the implementation of memset and similar functions. The current ARM optimized memset code does not return the value of its first argument, as is usually expected from standard implementations. For instance in the following function: void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter) { memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter)); waiter->magic = waiter; INIT_LIST_HEAD(&waiter->list); } compiled as: 800554d0 <debug_mutex_lock_common>: 800554d0: e92d4008 push {r3, lr} 800554d4: e1a00001 mov r0, r1 800554d8: e3a02010 mov r2, #16 ; 0x10 800554dc: e3a01011 mov r1, #17 ; 0x11 800554e0: eb04426e bl 80165ea0 <memset> 800554e4: e1a03000 mov r3, r0 800554e8: e583000c str r0, [r3, #12] 800554ec: e5830000 str r0, [r3] 800554f0: e5830004 str r0, [r3, #4] 800554f4: e8bd8008 pop {r3, pc} GCC assumes memset returns the value of pointer 'waiter' in register r0; causing register/memory corruptions. This patch fixes the return value of the assembly version of memset. It adds a 'mov' instruction and merges an additional load+store into existing load/store instructions. For ease of review, here is a breakdown of the patch into 4 simple steps: Step 1 ====== Perform the following substitutions: ip -> r8, then r0 -> ip, and insert 'mov ip, r0' as the first statement of the function. At this point, we have a memset() implementation returning the proper result, but corrupting r8 on some paths (the ones that were using ip). Step 2 ====== Make sure r8 is saved and restored when (! CALGN(1)+0) == 1: save r8: - str lr, [sp, #-4]! + stmfd sp!, {r8, lr} and restore r8 on both exit paths: - ldmeqfd sp!, {pc} @ Now <64 bytes to go. + ldmeqfd sp!, {r8, pc} @ Now <64 bytes to go. (...) tst r2, #16 stmneia ip!, {r1, r3, r8, lr} - ldr lr, [sp], #4 + ldmfd sp!, {r8, lr} Step 3 ====== Make sure r8 is saved and restored when (! CALGN(1)+0) == 0: save r8: - stmfd sp!, {r4-r7, lr} + stmfd sp!, {r4-r8, lr} and restore r8 on both exit paths: bgt 3b - ldmeqfd sp!, {r4-r7, pc} + ldmeqfd sp!, {r4-r8, pc} (...) tst r2, #16 stmneia ip!, {r4-r7} - ldmfd sp!, {r4-r7, lr} + ldmfd sp!, {r4-r8, lr} Step 4 ====== Rewrite register list "r4-r7, r8" as "r4-r8". Signed-off-by: Ivan Djelic <ivan.djelic@parrot.com> Reviewed-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Dirk Behme <dirk.behme@gmail.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| * | ARM: 7667/1: perf: Fix section mismatch on armpmu_init()Stephen Boyd2013-03-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | WARNING: vmlinux.o(.text+0xfb80): Section mismatch in reference from the function armpmu_register() to the function .init.text:armpmu_init() The function armpmu_register() references the function __init armpmu_init(). This is often because armpmu_register lacks a __init annotation or the annotation of armpmu_init is wrong. Just drop the __init marking on armpmu_init() because armpmu_register() no longer has an __init marking. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| * | ARM: 7666/1: decompressor: add -mno-single-pic-base for building the ↵Jonathan Austin2013-03-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | decompressor Before jumping to (position independent) C-code from the decompressor's assembler world we set-up the C environment. This setup currently does not set r9, which for arm-none-uclinux-uclibceabi toolchains is by default expected to be the PIC offset base register (IE should point to the beginning of the GOT). Currently, therefore, in order to build working kernels that use the decompressor it is necessary to use an arm-linux-gnueabi toolchain, or similar. uClinux toolchains cause a prefetch abort to occur at the beginning of the decompress_kernel function. This patch allows uClinux toolchains to build bootable zImages by forcing the -mno-single-pic-base option, which ensures that the location of the GOT is re-derived each time it is required, and r9 becomes free for use as a general purpose register. This has a small (4% in instruction terms) advantage over the alternative of setting r9 to point to the GOT before calling into the C-world. Signed-off-by: Jonathan Austin <jonathan.austin@arm.com> Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| * | ARM: 7665/1: Wire up kcmp syscallCyrill Gorcunov2013-03-032-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Wire up kcmp syscall for ability to proceed checkpoint/restore procedure on ARM platform. Signed-off-by: Alexander Kartashov <alekskartashov@parallels.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| * | ARM: 7664/1: perf: remove erroneous semicolon from event initialisationChen Gang2013-03-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 9dcbf466559f ("ARM: perf: simplify __hw_perf_event_init err handling") tidied up the error handling code for perf event initialisation on ARM, but a copy-and-paste error left a dangling semicolon at the end of an if statement. This patch removes the broken semicolon, restoring the old group validation semantics. Cc: Mark Rutland <mark.rutland@arm.com> Acked-by: Dirk Behme <dirk.behme@gmail.com> Signed-off-by: Chen Gang <gang.chen@asianux.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| * | ARM: 7663/1: perf: fix ARMv7 EVTYPE_MASK to include NSH bitWill Deacon2013-03-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Masked out PMXEVTYPER.NSH means that we can't enable profiling at PL2, regardless of the settings in the HDCR. This patch fixes the broken mask. Cc: <stable@vger.kernel.org> Reported-by: Christoffer Dall <cdall@cs.columbia.edu> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| * | ARM: 7662/1: hw_breakpoint: reset debug logic on secondary CPUs in s2ram resumeDietmar Eggemann2013-03-031-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We must mask out the CPU_TASKS_FROZEN bit so that reset_ctrl_regs is also called on a secondary CPU during s2ram resume, where only the boot CPU will receive the PM_EXIT notification. Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| * | ARM: 7661/1: mm: perform explicit branch predictor maintenance when requiredWill Deacon2013-03-034-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ARM ARM requires branch predictor maintenance if, for a given ASID, the instructions at a specific virtual address appear to change. From the kernel's point of view, that means: - Changing the kernel's view of memory (e.g. switching to the identity map) - ASID rollover (since ASIDs will be re-allocated to new tasks) This patch adds explicit branch predictor maintenance when either of the two conditions above are met. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| * | ARM: 7660/1: tlb: add branch predictor maintenance operationsWill Deacon2013-03-032-6/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ARM architecture requires explicit branch predictor maintenance when updating an instruction stream for a given virtual address. In reality, this isn't so much of a burden because the branch predictor is flushed during the cache maintenance required to make the new instructions visible to the I-side of the processor. However, there are still some cases where explicit flushing is required, so add a local_bp_flush_all operation to deal with this. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| * | ARM: 7659/1: mm: make mm->context.id an atomic64_t variableWill Deacon2013-03-034-14/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | mm->context.id is updated under asid_lock when a new ASID is allocated to an mm_struct. However, it is also read without the lock when a task is being scheduled and checking whether or not the current ASID generation is up-to-date. If two threads of the same process are being scheduled in parallel and the bottom bits of the generation in their mm->context.id match the current generation (that is, the mm_struct has not been used for ~2^24 rollovers) then the non-atomic, lockless access to mm->context.id may yield the incorrect ASID. This patch fixes this issue by making mm->context.id and atomic64_t, ensuring that the generation is always read consistently. For code that only requires access to the ASID bits (e.g. TLB flushing by mm), then the value is accessed directly, which GCC converts to an ldrb. Cc: <stable@vger.kernel.org> # 3.8 Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| * | ARM: 7658/1: mm: fix race updating mm->context.id on ASID rolloverWill Deacon2013-03-031-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a thread triggers an ASID rollover, other threads of the same process must be made to wait until the mm->context.id for the shared mm_struct has been updated to new generation and associated book-keeping (e.g. TLB invalidation) has ben performed. However, there is a *tiny* window where both mm->context.id and the relevant active_asids entry are updated to the new generation, but the TLB flush has not been performed, which could allow another thread to return to userspace with a dirty TLB, potentially leading to data corruption. In reality this will never occur because one CPU would need to perform a context-switch in the time it takes another to do a couple of atomic test/set operations but we should plug the race anyway. This patch moves the active_asids update until after the potential TLB flush on context-switch. Cc: <stable@vger.kernel.org> # 3.8 Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| * | ARM: 7657/1: head: fix swapper and idmap population with LPAE and big-endianWill Deacon2013-03-031-4/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The LPAE page table format uses 64-bit descriptors, so we need to take endianness into account when populating the swapper and idmap tables during early initialisation. This patch ensures that we store the two words making up each page table entry in the correct order when running big-endian. Cc: <stable@vger.kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| * | ARM: 7655/1: smp_twd: make twd_local_timer_of_register() no-op for nosmpShawn Guo2013-03-031-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When booting a SMP build kernel with nosmp on kernel cmdline, the following fat warning will be hit. ------------[ cut here ]------------ WARNING: at arch/arm/kernel/smp_twd.c:345 twd_local_timer_of_register+0x7c/0x90() twd_local_timer_of_register failed (-6) Modules linked in: Backtrace: [<80011f14>] (dump_backtrace+0x0/0x10c) from [<8044dd30>] (dump_stack+0x18/0x1c) r7:805e9f58 r6:805ba84c r5:80539331 r4:00000159 [<8044dd18>] (dump_stack+0x0/0x1c) from [<80020fbc>] (warn_slowpath_common+0x54/0x6c) [<80020f68>] (warn_slowpath_common+0x0/0x6c) from [<80021078>] (warn_slowpath_fmt+0x38/0x40) r9:412fc09a r8:8fffffff r7:ffffffff r6:00000001 r5:80633b8c r4:80b32da8 [<80021040>] (warn_slowpath_fmt+0x0/0x40) from [<805ba84] (twd_local_timer_of_register+0x7c/0x90) r3:fffffffa r2:8053934b [<805ba7d0>] (twd_local_timer_of_register+0x0/0x90) from [<805c0bec>] (imx6q_timer_init+0x18/0x4c) r5:80633800 r4:8053b701 [<805c0bd4>] (imx6q_timer_init+0x0/0x4c) from [<805ba4e8>] (time_init+0x28/0x38) r5:80633800 r4:805dc0f4 [<805ba4c0>] (time_init+0x0/0x38) from [<805b6854>] (start_kernel+0x1a0/0x310) [<805b66b4>] (start_kernel+0x0/0x310) from [<10008044>] (0x10008044) r8:1000406a r7:805f3f8c r6:805dc0c4 r5:805f0518 r4:10c5387d ---[ end trace 1b75b31a2719ed1c ]--- Check (!is_smp() || !setup_max_cpus) in twd_local_timer_of_register() to make it be a no-op for the conditions, thus avoid above warning. Reported-by: Dirk Behme <dirk.behme@de.bosch.com> Signed-off-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| * | ARM: 7652/1: mm: fix missing use of 'asid' to get asid value from mm->context.idBen Dooks2013-03-031-1/+1
| | | | | | | | | | | | | | | | | | | | | Fix missing use of the asid macro when getting the ASID from the mm->context.id field. Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| * | ARM: 7642/1: netx: bump IRQ offset to 64Linus Walleij2013-03-032-33/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Netx IRQs offset from zero, which is illegal, since Linux IRQ 0 is NO_IRQ. Acked-by: Sascha Hauer <s.hauer@pengutronix.de> Reviewed-by: Jamie Iles <jamie@jamieiles.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* | | powerpc: Set DSCR bit in FSCR setupMichael Neuling2013-03-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We support DSCR (Data Stream Control Register) so we should make sure we set it in the FSCR (Facility Status & Control Register) incase some firmwares don't set it. If we don't set this, we'll take a facility unavailable exception when using the DSCR. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* | | powerpc: Add DSCR FSCR register bit definitionMichael Neuling2013-03-051-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This sets the DSCR (Data Stream Control Register) in the FSCR (Facility Status & Control Register). Also harmonise TAR (Target Address Register) FSCR bit definition too. Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* | | powerpc: Fix setting FSCR for HV=0 and on secondary CPUsMichael Neuling2013-03-051-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently we only set the FSCR (Facility Status and Control Register) when HV=1 but this feature is available when HV=0 also. This patch sets FSCR when HV=0. Also, we currently only set the FSCR on the master CPU. This patch also sets the FSCR on secondary CPUs. Signed-off-by: Michael Neuling <mikey@neuling.org> cc: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* | | powerpc: Wireup the kcmp syscall to sys_niTony Breeds2013-03-053-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | Since kmp takes 2 unsigned long args there should be a compat wrapper. Since one isn't provided I think it's safer just to hook this up to not implemented. If we need it later we can do it properly then. Signed-off-by: Tony Breeds <tony@bakeyournoodle.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* | | powerpc: Remove unused BITOP_LE_SWIZZLE macroAkinobu Mita2013-03-051-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The BITOP_LE_SWIZZLE macro was used in the little-endian bitops functions for powerpc. But these functions were converted to generic bitops and the BITOP_LE_SWIZZLE is not used anymore. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* | | powerpc: Avoid link stack corruption in MMU on syscall entry pathMichael Neuling2013-03-051-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently we use the link register to branch up high in the early MMU on syscall entry path. Unfortunately, this trashes the link stack as the address we are going to is not associated with the earlier mflr. This patch simply converts us to used the count register (volatile over syscalls anyway) instead. This is much better at predicting in this scenario and doesn't trash link stack causing a bunch of additional branch mispredicts later. Benchmarking this on POWER8 saves a bunch of cycles on Anton's null syscall benchmark here: http://ozlabs.org/~anton/junkcode/null_syscall.c Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* | | powerpc/pseries/hvcserver: Fix strncpy buffer limit in location codeChen Gang2013-03-051-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | the dest buf len is 80 (HVCS_CLC_LENGTH + 1). the src buf len is PAGE_SIZE. if src buf string len is more than 80, it will cause issue. Signed-off-by: Chen Gang <gang.chen@asianux.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* | | powerpc: Fix compile of sha1-powerpc-asm.S on 32-bitTony Breeds2013-03-051-2/+2
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | When building with CRYPTO_SHA1_PPC enabled we fail with: powerpc/crypto/sha1-powerpc-asm.S: Assembler messages: powerpc/crypto/sha1-powerpc-asm.S:116: Error: can't resolve `0' {*ABS* section} - `STACKFRAMESIZE' {*UND* section} powerpc/crypto/sha1-powerpc-asm.S:116: Error: expression too complex powerpc/crypto/sha1-powerpc-asm.S:178: Error: unsupported relocation against STACKFRAMESIZE Use INT_FRAME_SIZE instead of STACKFRAMESIZE. Signed-off-by: Tony Breeds <tony@bakeyournoodle.com> Tested-by: Christian Kujau <lists@nerdbynature.de> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* | Merge tag 'stable/for-linus-3.9-rc1-tag' of ↵Linus Torvalds2013-03-032-1/+18
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen Pull Xen bug-fixes from Konrad Rzeszutek Wilk: - Update the Xen ACPI memory and CPU hotplug locking mechanism. - Fix PAT issues wherein various applications would not start - Fix handling of multiple MSI as AHCI now does it. - Fix ARM compile failures. * tag 'stable/for-linus-3.9-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: xenbus: fix compile failure on ARM with Xen enabled xen/pci: We don't do multiple MSI's. xen/pat: Disable PAT using pat_enabled value. xen/acpi: xen cpu hotplug minor updates xen/acpi: xen memory hotplug minor updates
| * xen/pci: We don't do multiple MSI's.Konrad Rzeszutek Wilk2013-03-011-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is no hypercall to setup multiple MSI per PCI device. As such with these two new commits: - 08261d87f7d1b6253ab3223756625a5c74532293 PCI/MSI: Enable multiple MSIs with pci_enable_msi_block_auto() - 5ca72c4f7c412c2002363218901eba5516c476b1 AHCI: Support multiple MSIs we would call the PHYSDEVOP_map_pirq 'nvec' times with the same contents of the PCI device. Sander discovered that we would get the same PIRQ value 'nvec' times and return said values to the caller. That of course meant that the device was configured only with one MSI and AHCI would fail with: ahci 0000:00:11.0: version 3.0 xen: registering gsi 19 triggering 0 polarity 1 xen: --> pirq=19 -> irq=19 (gsi=19) (XEN) [2013-02-27 19:43:07] IOAPIC[0]: Set PCI routing entry (6-19 -> 0x99 -> IRQ 19 Mode:1 Active:1) ahci 0000:00:11.0: AHCI 0001.0200 32 slots 4 ports 6 Gbps 0xf impl SATA mode ahci 0000:00:11.0: flags: 64bit ncq sntf ilck pm led clo pmp pio slum part ahci: probe of 0000:00:11.0 failed with error -22 That is b/c in ahci_host_activate the second call to devm_request_threaded_irq would return -EINVAL as we passed in (on the second run) an IRQ that was never initialized. CC: stable@vger.kernel.org Reported-and-Tested-by: Sander Eikelenboom <linux@eikelenboom.it> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| * xen/pat: Disable PAT using pat_enabled value.Konrad Rzeszutek Wilk2013-02-281-1/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The git commit 8eaffa67b43e99ae581622c5133e20b0f48bcef1 (xen/pat: Disable PAT support for now) explains in details why we want to disable PAT for right now. However that change was not enough and we should have also disabled the pat_enabled value. Otherwise we end up with: mmap-example:3481 map pfn expected mapping type write-back for [mem 0x00010000-0x00010fff], got uncached-minus ------------[ cut here ]------------ WARNING: at /build/buildd/linux-3.8.0/arch/x86/mm/pat.c:774 untrack_pfn+0xb8/0xd0() mem 0x00010000-0x00010fff], got uncached-minus ------------[ cut here ]------------ WARNING: at /build/buildd/linux-3.8.0/arch/x86/mm/pat.c:774 untrack_pfn+0xb8/0xd0() ... Pid: 3481, comm: mmap-example Tainted: GF 3.8.0-6-generic #13-Ubuntu Call Trace: [<ffffffff8105879f>] warn_slowpath_common+0x7f/0xc0 [<ffffffff810587fa>] warn_slowpath_null+0x1a/0x20 [<ffffffff8104bcc8>] untrack_pfn+0xb8/0xd0 [<ffffffff81156c1c>] unmap_single_vma+0xac/0x100 [<ffffffff81157459>] unmap_vmas+0x49/0x90 [<ffffffff8115f808>] exit_mmap+0x98/0x170 [<ffffffff810559a4>] mmput+0x64/0x100 [<ffffffff810560f5>] dup_mm+0x445/0x660 [<ffffffff81056d9f>] copy_process.part.22+0xa5f/0x1510 [<ffffffff81057931>] do_fork+0x91/0x350 [<ffffffff81057c76>] sys_clone+0x16/0x20 [<ffffffff816ccbf9>] stub_clone+0x69/0x90 [<ffffffff816cc89d>] ? system_call_fastpath+0x1a/0x1f ---[ end trace 4918cdd0a4c9fea4 ]--- (a similar message shows up if you end up launching 'mcelog') The call chain is (as analyzed by Liu, Jinsong): do_fork --> copy_process --> dup_mm --> dup_mmap --> copy_page_range --> track_pfn_copy --> reserve_pfn_range --> line 624: flags != want_flags It comes from different memory types of page table (_PAGE_CACHE_WB) and MTRR (_PAGE_CACHE_UC_MINUS). Stefan Bader dug in this deep and found out that: "That makes it clearer as this will do reserve_memtype(...) --> pat_x_mtrr_type --> mtrr_type_lookup --> __mtrr_type_lookup And that can return -1/0xff in case of MTRR not being enabled/initialized. Which is not the case (given there are no messages for it in dmesg). This is not equal to MTRR_TYPE_WRBACK and thus becomes _PAGE_CACHE_UC_MINUS. It looks like the problem starts early in reserve_memtype: if (!pat_enabled) { /* This is identical to page table setting without PAT */ if (new_type) { if (req_type == _PAGE_CACHE_WC) *new_type = _PAGE_CACHE_UC_MINUS; else *new_type = req_type & _PAGE_CACHE_MASK; } return 0; } This would be what we want, that is clearing the PWT and PCD flags from the supported flags - if pat_enabled is disabled." This patch does that - disabling PAT. CC: stable@vger.kernel.org # 3.3 and further Reported-by: Sander Eikelenboom <linux@eikelenboom.it> Reported-and-Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reported-and-Tested-by: Stefan Bader <stefan.bader@canonical.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>