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2014-04-08Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull second set of arm64 updates from Catalin Marinas: "A second pull request for this merging window, mainly with fixes and docs clarification: - Documentation clarification on CPU topology and booting requirements - Additional cache flushing during boot (needed in the presence of external caches or under virtualisation) - DMA range invalidation fix for non cache line aligned buffers - Build failure fix with !COMPAT - Kconfig update for STRICT_DEVMEM" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: Fix DMA range invalidation for cache line unaligned buffers arm64: Add missing Kconfig for CONFIG_STRICT_DEVMEM arm64: fix !CONFIG_COMPAT build failures Revert "arm64: virt: ensure visibility of __boot_cpu_mode" arm64: Relax the kernel cache requirements for boot arm64: Update the TCR_EL1 translation granule definitions for 16K pages ARM: topology: Make it clear that all CPUs need to be described
2014-04-07Merge branch 'akpm' (incoming from Andrew)Linus Torvalds
Merge second patch-bomb from Andrew Morton: - the rest of MM - zram updates - zswap updates - exit - procfs - exec - wait - crash dump - lib/idr - rapidio - adfs, affs, bfs, ufs - cris - Kconfig things - initramfs - small amount of IPC material - percpu enhancements - early ioremap support - various other misc things * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (156 commits) MAINTAINERS: update Intel C600 SAS driver maintainers fs/ufs: remove unused ufs_super_block_third pointer fs/ufs: remove unused ufs_super_block_second pointer fs/ufs: remove unused ufs_super_block_first pointer fs/ufs/super.c: add __init to init_inodecache() doc/kernel-parameters.txt: add early_ioremap_debug arm64: add early_ioremap support arm64: initialize pgprot info earlier in boot x86: use generic early_ioremap mm: create generic early_ioremap() support x86/mm: sparse warning fix for early_memremap lglock: map to spinlock when !CONFIG_SMP percpu: add preemption checks to __this_cpu ops vmstat: use raw_cpu_ops to avoid false positives on preemption checks slub: use raw_cpu_inc for incrementing statistics net: replace __this_cpu_inc in route.c with raw_cpu_inc modules: use raw_cpu_write for initialization of per cpu refcount. mm: use raw_cpu ops for determining current NUMA node percpu: add raw_cpu_ops slub: fix leak of 'name' in sysfs_slab_add ...
2014-04-07arm64: add early_ioremap supportMark Salter
Add support for early IO or memory mappings which are needed before the normal ioremap() is usable. This also adds fixmap support for permanent fixed mappings such as that used by the earlyprintk device register region. Signed-off-by: Mark Salter <msalter@redhat.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Borislav Petkov <borislav.petkov@amd.com> Cc: Dave Young <dyoung@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07arm64: initialize pgprot info earlier in bootMark Salter
Presently, paging_init() calls init_mem_pgprot() to initialize pgprot values used by macros such as PAGE_KERNEL, PAGE_KERNEL_EXEC, etc. The new fixmap and early_ioremap support also needs to use these macros before paging_init() is called. This patch moves the init_mem_pgprot() call out of paging_init() and into setup_arch() so that pgprot_default gets initialized in time for fixmap and early_ioremap. Signed-off-by: Mark Salter <msalter@redhat.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Borislav Petkov <borislav.petkov@amd.com> Cc: Dave Young <dyoung@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07Merge tag 'cpu-hotplug-3.15-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull CPU hotplug notifiers registration fixes from Rafael Wysocki: "The purpose of this single series of commits from Srivatsa S Bhat (with a small piece from Gautham R Shenoy) touching multiple subsystems that use CPU hotplug notifiers is to provide a way to register them that will not lead to deadlocks with CPU online/offline operations as described in the changelog of commit 93ae4f978ca7f ("CPU hotplug: Provide lockless versions of callback registration functions"). The first three commits in the series introduce the API and document it and the rest simply goes through the users of CPU hotplug notifiers and converts them to using the new method" * tag 'cpu-hotplug-3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (52 commits) net/iucv/iucv.c: Fix CPU hotplug callback registration net/core/flow.c: Fix CPU hotplug callback registration mm, zswap: Fix CPU hotplug callback registration mm, vmstat: Fix CPU hotplug callback registration profile: Fix CPU hotplug callback registration trace, ring-buffer: Fix CPU hotplug callback registration xen, balloon: Fix CPU hotplug callback registration hwmon, via-cputemp: Fix CPU hotplug callback registration hwmon, coretemp: Fix CPU hotplug callback registration thermal, x86-pkg-temp: Fix CPU hotplug callback registration octeon, watchdog: Fix CPU hotplug callback registration oprofile, nmi-timer: Fix CPU hotplug callback registration intel-idle: Fix CPU hotplug callback registration clocksource, dummy-timer: Fix CPU hotplug callback registration drivers/base/topology.c: Fix CPU hotplug callback registration acpi-cpufreq: Fix CPU hotplug callback registration zsmalloc: Fix CPU hotplug callback registration scsi, fcoe: Fix CPU hotplug callback registration scsi, bnx2fc: Fix CPU hotplug callback registration scsi, bnx2i: Fix CPU hotplug callback registration ...
2014-04-06arm64: fix !CONFIG_COMPAT build failuresMark Salter
Recent arm64 builds using CONFIG_ARM64_64K_PAGES are failing with: arch/arm64/kernel/perf_regs.c: In function ‘perf_reg_abi’: arch/arm64/kernel/perf_regs.c:41:2: error: implicit declaration of function ‘is_compat_thread’ arch/arm64/kernel/perf_event.c:1398:2: error: unknown type name ‘compat_uptr_t’ This is due to some recent arm64 perf commits with compat support: commit 23c7d70d55c6d9: ARM64: perf: add support for frame pointer unwinding in compat mode commit 2ee0d7fd36a3f8: ARM64: perf: add support for perf registers API Those patches make the arm64 kernel unbuildable if CONFIG_COMPAT is not defined and CONFIG_ARM64_64K_PAGES depends on !CONFIG_COMPAT. This patch allows the arm64 kernel to build with and without CONFIG_COMPAT. Signed-off-by: Mark Salter <msalter@redhat.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-04-05arm64: Relax the kernel cache requirements for bootCatalin Marinas
With system caches for the host OS or architected caches for guest OS we cannot easily guarantee that there are no dirty or stale cache lines for the areas of memory written by the kernel during boot with the MMU off (therefore non-cacheable accesses). This patch adds the necessary cache maintenance during boot and relaxes the booting requirements. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-03-31Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull ARM64 updates from Catalin Marinas: - KGDB support for arm64 - PCI I/O space extended to 16M (in preparation of PCIe support patches) - Dropping ZONE_DMA32 in favour of ZONE_DMA (we only need one for the time being), together with swiotlb late initialisation to correctly setup the bounce buffer - DMA API cache maintenance support (not all ARMv8 platforms have hardware cache coherency) - Crypto extensions advertising via ELF_HWCAP2 for compat user space - Perf support for dwarf unwinding in compat mode - asm/tlb.h converted to the generic mmu_gather code - asm-generic rwsem implementation - Code clean-up * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (42 commits) arm64: Remove pgprot_dmacoherent() arm64: Support DMA_ATTR_WRITE_COMBINE arm64: Implement custom mmap functions for dma mapping arm64: Fix __range_ok macro arm64: Fix duplicated Kconfig entries arm64: mm: Route pmd thp functions through pte equivalents arm64: rwsem: use asm-generic rwsem implementation asm-generic: rwsem: de-PPCify rwsem.h arm64: enable generic CPU feature modalias matching for this architecture arm64: smp: make local symbol static arm64: debug: make local symbols static ARM64: perf: support dwarf unwinding in compat mode ARM64: perf: add support for frame pointer unwinding in compat mode ARM64: perf: add support for perf registers API arm64: Add boot time configuration of Intermediate Physical Address size arm64: Do not synchronise I and D caches for special ptes arm64: Make DMA coherent and strongly ordered mappings not executable arm64: barriers: add dmb barrier arm64: topology: Implement basic CPU topology support arm64: advertise ARMv8 extensions to 32-bit compat ELF binaries ...
2014-03-20arm64, debug-monitors: Fix CPU hotplug callback registrationSrivatsa S. Bhat
Subsystems that want to register CPU hotplug callbacks, as well as perform initialization for the CPUs that are already online, often do it as shown below: get_online_cpus(); for_each_online_cpu(cpu) init_cpu(cpu); register_cpu_notifier(&foobar_cpu_notifier); put_online_cpus(); This is wrong, since it is prone to ABBA deadlocks involving the cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently with CPU hotplug operations). Instead, the correct and race-free way of performing the callback registration is: cpu_notifier_register_begin(); for_each_online_cpu(cpu) init_cpu(cpu); /* Note the use of the double underscored version of the API */ __register_cpu_notifier(&foobar_cpu_notifier); cpu_notifier_register_done(); Fix the debug-monitors code in arm64 by using this latter form of callback registration. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Ingo Molnar <mingo@kernel.org> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-03-20arm64, hw_breakpoint.c: Fix CPU hotplug callback registrationSrivatsa S. Bhat
Subsystems that want to register CPU hotplug callbacks, as well as perform initialization for the CPUs that are already online, often do it as shown below: get_online_cpus(); for_each_online_cpu(cpu) init_cpu(cpu); register_cpu_notifier(&foobar_cpu_notifier); put_online_cpus(); This is wrong, since it is prone to ABBA deadlocks involving the cpu_add_remove_lock and the cpu_hotplug.lock (when running concurrently with CPU hotplug operations). Instead, the correct and race-free way of performing the callback registration is: cpu_notifier_register_begin(); for_each_online_cpu(cpu) init_cpu(cpu); /* Note the use of the double underscored version of the API */ __register_cpu_notifier(&foobar_cpu_notifier); cpu_notifier_register_done(); Fix the hw-breakpoint code in arm64 by using this latter form of callback registration. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com> Cc: Ingo Molnar <mingo@kernel.org> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-03-13arm64: smp: make local symbol staticJingoo Han
Make smp_spin_table_cpu_postboot() static, because this function is used only in this file. Signed-off-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-03-13arm64: debug: make local symbols staticJingoo Han
Make local symbols static, because these are used only in this file. Signed-off-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-03-13ARM64: perf: add support for frame pointer unwinding in compat modeJean Pihet
When profiling a 32-bit application, user space callchain unwinding using the frame pointer is performed in compat mode. The code is taken over from the AARCH32 code and adapted to work on AARCH64. Signed-off-by: Jean Pihet <jean.pihet@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-03-13ARM64: perf: add support for perf registers APIJean Pihet
This patch implements the functions required for the perf registers API, allowing the perf tool to interface kernel register dumps with libunwind in order to provide userspace backtracing. Compat mode is also supported. Only the general purpose user space registers are exported, i.e.: PERF_REG_ARM_X0, ... PERF_REG_ARM_X28, PERF_REG_ARM_FP, PERF_REG_ARM_LR, PERF_REG_ARM_SP, PERF_REG_ARM_PC and not the PERF_REG_ARM_V* registers. Signed-off-by: Jean Pihet <jean.pihet@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-03-11Merge branch 'sched/urgent' into sched/coreIngo Molnar
Pick up fixes before queueing up new changes. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-03-04arm64: topology: Implement basic CPU topology supportMark Brown
Add basic CPU topology support to arm64, based on the existing pre-v8 code and some work done by Mark Hambleton. This patch does not implement any topology discovery support since that should be based on information from firmware, it merely implements the scaffolding for integration of topology support in the architecture. No locking of the topology data is done since it is only modified during CPU bringup with external serialisation from the SMP code. The goal is to separate the architecture hookup for providing topology information from the DT parsing in order to ease review and avoid blocking the architecture code (which will be built on by other work) with the DT code review by providing something simple and basic. Following patches will implement support for interpreting topology information from MPIDR and for parsing the DT topology bindings for ARM, similar patches will be needed for ACPI. Signed-off-by: Mark Brown <broonie@linaro.org> Acked-by: Mark Rutland <mark.rutland@arm.com> [catalin.marinas@arm.com: removed CONFIG_CPU_TOPOLOGY, always on if SMP] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-03-04arm64: advertise ARMv8 extensions to 32-bit compat ELF binariesArd Biesheuvel
This adds support for advertising the presence of ARMv8 Crypto Extensions in the Aarch32 execution state to 32-bit ELF binaries running in 32-bit compat mode under the arm64 kernel. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-03-04arm64: add AT_HWCAP2 support for 32-bit compatArd Biesheuvel
Add support for the ELF auxv entry AT_HWCAP2 when running 32-bit ELF binaries in compat mode. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-28arm64: remove return value form psci_init()Vladimir Murzin
psci_init() is written to return err code if something goes wrong. However, the single user, setup_arch(), doesn't care about it. Moreover, every error path is supplied with a clear message which is enough for pleasant debugging. Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-28arm64: remove redundant "psci:" prefixesVladimir Murzin
Since 652af899799354049b273af897b798b8f03fdd88 "arm64: factor out spin-table boot method" psci prefix's been introduced. We have a common pr_fmt, so clean them up. Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-26arm64: vdso: clean up vdso_pagelist initializationNathan Lynch
Remove some unnecessary bits that were apparently carried over from another architecture's implementation: - No need to get_page() the vdso text/data - these are part of the kernel image. - No need for ClearPageReserved on the vdso text. - No need to vmap the first text page to check the ELF header - this can be done through &vdso_start. Also some minor cleanup: - Use kcalloc for vdso_pagelist array allocation. - Don't print on allocation failure, slab/slub will do that for us. Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-26arm64: Fix the soft_restart routineGeoff Levand
Change the soft_restart() routine to call cpu_reset() at its identity mapped physical address. The cpu_reset() routine must be called at its identity mapped physical address so that when the MMU is turned off the instruction pointer will be at the correct location in physical memory. Signed-off-by: Geoff Levand <geoff@infradead.org> for Huawei, Linaro Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-26arm64: Extend the idmap to the whole kernel imageCatalin Marinas
This patch changes the idmap page table creation during boot to cover the whole kernel image, allowing functions like cpu_reset() to be safely called with the physical address. This patch also simplifies the create_block_map asm macro to no longer take an idmap argument and always use the phys/virt/end parameters. For the idmap case, phys == virt. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-26arm64: enable processor debug state for secondary cpusVijaya Kumar K
processor debug state PSTATE.D is unmasked in smp call clear_os_lock for secondary cpus. So debug state is still masked in normal kernel context. With this patch, unmask debug state on secondary boot for the cpus in normal kernel context. Now kgdb tests passed with multicore. Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@caviumnetworks.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-26arm64: KGDB: Add step debugging supportVijaya Kumar K
Add KGDB software step debugging support for EL1 debug in AArch64 mode. KGDB registers step debug handler with debug monitor. On receiving 'step' command from GDB tool, target enables software step debugging and step address is updated in ELR. Software Step debugging is disabled when 'continue' command is received Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@caviumnetworks.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-26arm64: KGDB: Add Basic KGDB supportVijaya Kumar K
Add KGDB debug support for kernel debugging. With this patch, basic KGDB debugging is possible.GDB register layout is updated and GDB tool can establish connection with target and can set/clear breakpoints. Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@caviumnetworks.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-26arm64: Add macros to manage processor debug stateVijaya Kumar K
Add macros to enable and disable to manage PSTATE.D for debugging. The macros local_dbg_save and local_dbg_restore are moved to irqflags.h file KGDB boot tests fail because of PSTATE.D is masked. unmask it for debugging support Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@caviumnetworks.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-22cpuidle/arm64: Remove redundant cpuidle_idle_call()Nicolas Pitre
The core idle loop now takes care of it. Signed-off-by: Nicolas Pitre <nico@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Deepthi Dharwar <deepthi@linux.vnet.ibm.com> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Cc: linux-pm@vger.kernel.org Cc: linaro-kernel@lists.linaro.org Link: http://lkml.kernel.org/n/tip-wk9vpc8dsn46s12pl602ljpo@git.kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-02-17ARM64: unwind: Fix PC calculationOlof Johansson
The frame PC value in the unwind code used to just take the saved LR value and use that. That's incorrect as a stack trace, since it shows the return path stack, not the call path stack. In particular, it shows faulty information in case the bl is done as the very last instruction of one label, since the return point will be in the next label. That can easily be seen with tail calls to panic(), which is marked __noreturn and thus doesn't have anything useful after it. Easiest here is to just correct the unwind code and do a -4, to get the actual call site for the backtrace instead of the return site. Signed-off-by: Olof Johansson <olof@lixom.net> Cc: stable@vger.kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-07arm64: atomics: fix use of acquire + release for full barrier semanticsWill Deacon
Linux requires a number of atomic operations to provide full barrier semantics, that is no memory accesses after the operation can be observed before any accesses up to and including the operation in program order. On arm64, these operations have been incorrectly implemented as follows: // A, B, C are independent memory locations <Access [A]> // atomic_op (B) 1: ldaxr x0, [B] // Exclusive load with acquire <op(B)> stlxr w1, x0, [B] // Exclusive store with release cbnz w1, 1b <Access [C]> The assumption here being that two half barriers are equivalent to a full barrier, so the only permitted ordering would be A -> B -> C (where B is the atomic operation involving both a load and a store). Unfortunately, this is not the case by the letter of the architecture and, in fact, the accesses to A and C are permitted to pass their nearest half barrier resulting in orderings such as Bl -> A -> C -> Bs or Bl -> C -> A -> Bs (where Bl is the load-acquire on B and Bs is the store-release on B). This is a clear violation of the full barrier requirement. The simple way to fix this is to implement the same algorithm as ARMv7 using explicit barriers: <Access [A]> // atomic_op (B) dmb ish // Full barrier 1: ldxr x0, [B] // Exclusive load <op(B)> stxr w1, x0, [B] // Exclusive store cbnz w1, 1b dmb ish // Full barrier <Access [C]> but this has the undesirable effect of introducing *two* full barrier instructions. A better approach is actually the following, non-intuitive sequence: <Access [A]> // atomic_op (B) 1: ldxr x0, [B] // Exclusive load <op(B)> stlxr w1, x0, [B] // Exclusive store with release cbnz w1, 1b dmb ish // Full barrier <Access [C]> The simple observations here are: - The dmb ensures that no subsequent accesses (e.g. the access to C) can enter or pass the atomic sequence. - The dmb also ensures that no prior accesses (e.g. the access to A) can pass the atomic sequence. - Therefore, no prior access can pass a subsequent access, or vice-versa (i.e. A is strictly ordered before C). - The stlxr ensures that no prior access can pass the store component of the atomic operation. The only tricky part remaining is the ordering between the ldxr and the access to A, since the absence of the first dmb means that we're now permitting re-ordering between the ldxr and any prior accesses. From an (arbitrary) observer's point of view, there are two scenarios: 1. We have observed the ldxr. This means that if we perform a store to [B], the ldxr will still return older data. If we can observe the ldxr, then we can potentially observe the permitted re-ordering with the access to A, which is clearly an issue when compared to the dmb variant of the code. Thankfully, the exclusive monitor will save us here since it will be cleared as a result of the store and the ldxr will retry. Notice that any use of a later memory observation to imply observation of the ldxr will also imply observation of the access to A, since the stlxr/dmb ensure strict ordering. 2. We have not observed the ldxr. This means we can perform a store and influence the later ldxr. However, that doesn't actually tell us anything about the access to [A], so we've not lost anything here either when compared to the dmb variant. This patch implements this solution for our barriered atomic operations, ensuring that we satisfy the full barrier requirements where they are needed. Cc: <stable@vger.kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-05arm64: vdso: update wtm fields for CLOCK_MONOTONIC_COARSENathan Lynch
Update wall-to-monotonic fields in the VDSO data page unconditionally. These are used to service CLOCK_MONOTONIC_COARSE, which is not guarded by use_syscall. Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com> Acked-by: Will Deacon <will.deacon@arm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-05arm64: vdso: fix coarse clock handlingNathan Lynch
When __kernel_clock_gettime is called with a CLOCK_MONOTONIC_COARSE or CLOCK_REALTIME_COARSE clock id, it returns incorrectly to whatever the caller has placed in x2 ("ret x2" to return from the fast path). Fix this by saving x30/LR to x2 only in code that will call __do_get_tspec, restoring x30 afterward, and using a plain "ret" to return from the routine. Also: while the resulting tv_nsec value for CLOCK_REALTIME and CLOCK_MONOTONIC must be computed using intermediate values that are left-shifted by cs_shift (x12, set by __do_get_tspec), the results for coarse clocks should be calculated using unshifted values (xtime_coarse_nsec is in units of actual nanoseconds). The current code shifts intermediate values by x12 unconditionally, but x12 is uninitialized when servicing a coarse clock. Fix this by setting x12 to 0 once we know we are dealing with a coarse clock id. Signed-off-by: Nathan Lynch <nathan_lynch@mentor.com> Acked-by: Will Deacon <will.deacon@arm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-04arm64: vdso: prevent ld from aligning PT_LOAD segments to 64kWill Deacon
Whilst the text segment for our VDSO is marked as PT_LOAD in the ELF headers, it is mapped by the kernel and not actually subject to demand-paging. ld doesn't realise this, and emits a p_align field of 64k (the maximum supported page size), which conflicts with the load address picked by the kernel on 4k systems, which will be 4k aligned. This causes GDB to fail with "Failed to read a valid object file image from memory" when attempting to load the VDSO. This patch passes the -n option to ld, which prevents it from aligning PT_LOAD segments to the maximum page size. Cc: <stable@vger.kernel.org> Reported-by: Kyle McMartin <kyle@redhat.com> Acked-by: Kyle McMartin <kyle@redhat.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-01-31Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pyll ARM64 patches from Catalin Marinas: - Build fix with DMA_CMA enabled - Introduction of PTE_WRITE to distinguish between writable but clean and truly read-only pages - FIQs enabling/disabling clean-up (they aren't used on arm64) - CPU resume fix for the per-cpu offset restoring - Code comment typos * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: mm: Introduce PTE_WRITE arm64: mm: Remove PTE_BIT_FUNC macro arm64: FIQs are unused arm64: mm: fix the function name in comment of cpu_do_switch_mm arm64: fix build error if DMA_CMA is enabled arm64: kernel: fix per-cpu offset restore on resume arm64: mm: fix the function name in comment of __flush_dcache_area arm64: mm: use ubfm for dcache_line_size
2014-01-30arm64: FIQs are unusedNicolas Pitre
So any FIQ handling is superfluous at the moment. The functions to disable/enable FIQs is kept around if ever someone needs them in the future, but existing calling sites including arch_cpu_idle_prepare() may go for now. Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-01-24arm64: kernel: fix per-cpu offset restore on resumeLorenzo Pieralisi
The introduction of percpu offset optimisation through tpidr_el1 in: Commit id :7158627686f02319c50c8d9d78f75d4c8 "arm64: percpu: implement optimised pcpu access using tpidr_el1" requires cpu_{suspend/resume} to restore the tpidr_el1 register upon resume so that percpu variables can be addressed correctly when a CPU comes out of reset from warm-boot. This patch fixes cpu_{suspend}/{resume} tpidr_el1 restoration on resume, by calling the set_my_cpu_offset C API, as it is done on primary and secondary CPUs on cold boot, so that, even if the register used to store the percpu offset is changed, the save and restore of general purpose registers does not have to be updated. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-01-20Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull ARM64 updates from Catalin Marinas: - CPU suspend support on top of PSCI (firmware Power State Coordination Interface) - jump label support - CMA can now be enabled on arm64 - HWCAP bits for crypto and CRC32 extensions - optimised percpu using tpidr_el1 register - code cleanup * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (42 commits) arm64: fix typo in entry.S arm64: kernel: restore HW breakpoint registers in cpu_suspend jump_label: use defined macros instead of hard-coding for better readability arm64, jump label: optimize jump label implementation arm64, jump label: detect %c support for ARM64 arm64: introduce aarch64_insn_gen_{nop|branch_imm}() helper functions arm64: move encode_insn_immediate() from module.c to insn.c arm64: introduce interfaces to hotpatch kernel and module code arm64: introduce basic aarch64 instruction decoding helpers arm64: dts: Reduce size of virtio block device for foundation model arm64: Remove unused __data_loc variable arm64: Enable CMA arm64: Warn on NULL device structure for dma APIs arm64: Add hwcaps for crypto and CRC32 extensions. arm64: drop redundant macros from read_cpuid() arm64: Remove outdated comment arm64: cmpxchg: update macros to prevent warnings arm64: support single-step and breakpoint handler hooks ARM64: fix framepointer check in unwind_frame ARM64: check stack pointer in get_wchan ...
2014-01-13arm64: fix typo in entry.SNeil Zhang
Commit 64681787 (arm64: let the core code deal with preempt_count) changed the code, but left the comments unchanged, fix it. Signed-off-by: Neil Zhang <zhangwm@marvell.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-01-10arm64: kernel: restore HW breakpoint registers in cpu_suspendLorenzo Pieralisi
When a CPU resumes from low-power, it restores HW breakpoint and watchpoint slots through a CPU PM notifier. Since we want to enable debugging as early as possible in the resume path, the mdscr content is restored along the general purpose registers in the cpu_suspend API and debug exceptions are reenabled when cpu_suspend returns. Since the CPU PM notifier is run after a CPU has been resumed, we cannot expect HW breakpoint registers to contain sane values till the notifier is run, since the HW breakpoints registers content is unknown at reset; this means that the CPU might run with debug exceptions enabled, mdscr restored but HW breakpoint registers containing junk values that can trigger spurious debug exceptions. This patch fixes current HW breakpoints restore by moving the HW breakpoints registers restoration to the cpu_suspend API, before the debug exceptions are enabled. This way, as soon as the cpu_suspend function returns the kernel can resume debugging with sane values in HW breakpoint registers. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-01-08arm64, jump label: optimize jump label implementationJiang Liu
Optimize jump label implementation for ARM64 by dynamically patching kernel text. Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Jiang Liu <liuj97@gmail.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-01-08arm64: introduce aarch64_insn_gen_{nop|branch_imm}() helper functionsJiang Liu
Introduce aarch64_insn_gen_{nop|branch_imm}() helper functions, which will be used to implement jump label on ARM64. Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Jiang Liu <liuj97@gmail.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-01-08arm64: move encode_insn_immediate() from module.c to insn.cJiang Liu
Function encode_insn_immediate() will be used by other instruction manipulate related functions, so move it into insn.c and rename it as aarch64_insn_encode_immediate(). Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Jiang Liu <liuj97@gmail.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-01-08arm64: introduce interfaces to hotpatch kernel and module codeJiang Liu
Introduce three interfaces to patch kernel and module code: aarch64_insn_patch_text_nosync(): patch code without synchronization, it's caller's responsibility to synchronize all CPUs if needed. aarch64_insn_patch_text_sync(): patch code and always synchronize with stop_machine() aarch64_insn_patch_text(): patch code and synchronize with stop_machine() if needed Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Jiang Liu <liuj97@gmail.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-01-08arm64: introduce basic aarch64 instruction decoding helpersJiang Liu
Introduce basic aarch64 instruction decoding helper aarch64_get_insn_class() and aarch64_insn_hotpatch_safe(). Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Jiang Liu <liuj97@gmail.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-12-20arm64: Remove unused __data_loc variableGeoff Levand
The __data_loc variable is an unused left over from the 32 bit arm implementation. Remove that variable and adjust the __mmap_switched startup routine accordingly. Signed-off-by: Geoff Levand <geoff@infradead.org> for Huawei, Linaro Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-12-19Merge tag 'arm64-suspend' of git://linux-arm.org/linux-2.6-lp into upstreamCatalin Marinas
* tag 'arm64-suspend' of git://linux-arm.org/linux-2.6-lp: arm64: add CPU power management menu/entries arm64: kernel: add PM build infrastructure arm64: kernel: add CPU idle call arm64: enable generic clockevent broadcast arm64: kernel: implement HW breakpoints CPU PM notifier arm64: kernel: refactor code to install/uninstall breakpoints arm: kvm: implement CPU PM notifier arm64: kernel: implement fpsimd CPU PM notifier arm64: kernel: cpu_{suspend/resume} implementation arm64: kernel: suspend/resume registers save/restore arm64: kernel: build MPIDR_EL1 hash function data structure arm64: kernel: add MPIDR_EL1 accessors macros Conflicts: arch/arm64/Kconfig
2013-12-19arm64: Add hwcaps for crypto and CRC32 extensions.Steve Capper
Advertise the optional cryptographic and CRC32 instructions to user space where present. Several hwcap bits [3-7] are allocated. Signed-off-by: Steve Capper <steve.capper@linaro.org> [bit 2 is taken now so use bits 3-7 instead] Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-12-19arm64: Remove outdated commentLiviu Dudau
Code referenced in the comment has moved to arch/arm64/kernel/cputable.c Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-12-19arm64: support single-step and breakpoint handler hooksSandeepa Prabhu
AArch64 Single Steping and Breakpoint debug exceptions will be used by multiple debug framworks like kprobes & kgdb. This patch implements the hooks for those frameworks to register their own handlers for handling breakpoint and single step events. Reworked the debug exception handler in entry.S: do_dbg to route software breakpoint (BRK64) exception to do_debug_exception() Signed-off-by: Sandeepa Prabhu <sandeepa.prabhu@linaro.org> Signed-off-by: Deepak Saxena <dsaxena@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-12-19ARM64: fix framepointer check in unwind_frameKonstantin Khlebnikov
We need at least 24 bytes above frame pointer. Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>