1. 23 Mar, 2015 1 commit
  2. 19 Mar, 2015 5 commits
  3. 17 Mar, 2015 2 commits
  4. 14 Mar, 2015 1 commit
    • Catalin Marinas's avatar
      arm64: Invalidate the TLB corresponding to intermediate page table levels · 285994a6
      Catalin Marinas authored
      The ARM architecture allows the caching of intermediate page table
      levels and page table freeing requires a sequence like:
      
      	pmd_clear()
      	TLB invalidation
      	pte page freeing
      
      With commit 5e5f6dc1 (arm64: mm: enable HAVE_RCU_TABLE_FREE logic),
      the page table freeing batching was moved from tlb_remove_page() to
      tlb_remove_table(). The former takes care of TLB invalidation as this is
      also shared with pte clearing and page cache page freeing. The latter,
      however, does not invalidate the TLBs for intermediate page table levels
      as it probably relies on the architecture code to do it if required.
      When the mm->mm_users < 2, tlb_remove_table() does not do any batching
      and page table pages are freed before tlb_finish_mmu() which performs
      the actual TLB invalidation.
      
      This patch introduces __tlb_flush_pgtable() for arm64 and calls it from
      the {pte,pmd,pud}_free_tlb() directly without relying on deferred page
      table freeing.
      
      Fixes: 5e5f6dc1
      
       arm64: mm: enable HAVE_RCU_TABLE_FREE logic
      Reported-by: default avatarJon Masters <jcm@redhat.com>
      Tested-by: default avatarJon Masters <jcm@redhat.com>
      Tested-by: default avatarSteve Capper <steve.capper@linaro.org>
      Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      285994a6
  5. 27 Feb, 2015 2 commits
    • Lorenzo Pieralisi's avatar
      arm64: cpuidle: add asm/proc-fns.h inclusion · af4819af
      Lorenzo Pieralisi authored
      
      
      ARM64 CPUidle driver requires the cpu_do_idle function so that it can
      be used to enter the shallowest idle state, and it is declared in
      asm/proc-fns.h.
      
      The current ARM64 CPUidle driver does not include asm/proc-fns.h
      explicitly and it has so far relied on implicit inclusion from other
      header files.
      
      Owing to some header dependencies reshuffling this currently triggers
      build failures when CONFIG_ARM64_64K_PAGES=y:
      
      drivers/cpuidle/cpuidle-arm64.c: In function "arm64_enter_idle_state"
      drivers/cpuidle/cpuidle-arm64.c:42:3: error: implicit declaration of
      function "cpu_do_idle" [-Werror=implicit-function-declaration]
         cpu_do_idle();
         ^
      
      This patch adds the explicit inclusion of the asm/proc-fns.h header file
      in the arm64 asm/cpuidle.h header file, so that the build breakage is fixed
      and the required header inclusion is added to the appropriate arch back-end
      CPUidle header, already included by the CPUidle arm64 driver, where
      CPUidle arch related function declarations belong.
      Reported-by: default avatarLaura Abbott <lauraa@codeaurora.org>
      Signed-off-by: default avatarLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
      Acked-by: default avatarWill Deacon <will.deacon@arm.com>
      Tested-by: default avatarMark Rutland <mark.rutland@arm.com>
      Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      af4819af
    • Catalin Marinas's avatar
      arm64: Increase the swiotlb buffer size 64MB · a1e50a82
      Catalin Marinas authored
      With commit 3690951f
      
       (arm64: Use swiotlb late initialisation), the
      swiotlb buffer size is limited to MAX_ORDER_NR_PAGES. However, there are
      platforms with 32-bit only devices that require bounce buffering via
      swiotlb. This patch changes the swiotlb initialisation to an early 64MB
      memblock allocation. In order to get the swiotlb buffer correctly
      allocated (via memblock_virt_alloc_low_nopanic), this patch also defines
      ARCH_LOW_ADDRESS_LIMIT to the maximum physical address capable of 32-bit
      DMA.
      Reported-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
      Tested-by: default avatarKefeng Wang <wangkefeng.wang@huawei.com>
      Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      a1e50a82
  6. 26 Feb, 2015 2 commits
  7. 23 Feb, 2015 2 commits
  8. 12 Feb, 2015 1 commit
    • Andy Lutomirski's avatar
      all arches, signal: move restart_block to struct task_struct · f56141e3
      Andy Lutomirski authored
      
      
      If an attacker can cause a controlled kernel stack overflow, overwriting
      the restart block is a very juicy exploit target.  This is because the
      restart_block is held in the same memory allocation as the kernel stack.
      
      Moving the restart block to struct task_struct prevents this exploit by
      making the restart_block harder to locate.
      
      Note that there are other fields in thread_info that are also easy
      targets, at least on some architectures.
      
      It's also a decent simplification, since the restart code is more or less
      identical on all architectures.
      
      [james.hogan@imgtec.com: metag: align thread_info::supervisor_stack]
      Signed-off-by: default avatarAndy Lutomirski <luto@amacapital.net>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Kees Cook <keescook@chromium.org>
      Cc: David Miller <davem@davemloft.net>
      Acked-by: default avatarRichard Weinberger <richard@nod.at>
      Cc: Richard Henderson <rth@twiddle.net>
      Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      Cc: Matt Turner <mattst88@gmail.com>
      Cc: Vineet Gupta <vgupta@synopsys.com>
      Cc: Russell King <rmk@arm.linux.org.uk>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
      Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
      Cc: Steven Miao <realmz6@gmail.com>
      Cc: Mark Salter <msalter@redhat.com>
      Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
      Cc: Mikael Starvik <starvik@axis.com>
      Cc: Jesper Nilsson <jesper.nilsson@axis.com>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Richard Kuo <rkuo@codeaurora.org>
      Cc: "Luck, Tony" <tony.luck@intel.com>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Michal Simek <monstr@monstr.eu>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
      Cc: Helge Deller <deller@gmx.de>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
      Tested-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Chen Liqin <liqin.linux@gmail.com>
      Cc: Lennox Wu <lennox.wu@gmail.com>
      Cc: Chris Metcalf <cmetcalf@ezchip.com>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Chris Zankel <chris@zankel.net>
      Cc: Max Filippov <jcmvbkbc@gmail.com>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Guenter Roeck <linux@roeck-us.net>
      Signed-off-by: default avatarJames Hogan <james.hogan@imgtec.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      f56141e3
  9. 11 Feb, 2015 1 commit
  10. 10 Feb, 2015 1 commit
  11. 06 Feb, 2015 1 commit
    • Paolo Bonzini's avatar
      kvm: add halt_poll_ns module parameter · f7819512
      Paolo Bonzini authored
      
      
      This patch introduces a new module parameter for the KVM module; when it
      is present, KVM attempts a bit of polling on every HLT before scheduling
      itself out via kvm_vcpu_block.
      
      This parameter helps a lot for latency-bound workloads---in particular
      I tested it with O_DSYNC writes with a battery-backed disk in the host.
      In this case, writes are fast (because the data doesn't have to go all
      the way to the platters) but they cannot be merged by either the host or
      the guest.  KVM's performance here is usually around 30% of bare metal,
      or 50% if you use cache=directsync or cache=writethrough (these
      parameters avoid that the guest sends pointless flush requests, and
      at the same time they are not slow because of the battery-backed cache).
      The bad performance happens because on every halt the host CPU decides
      to halt itself too.  When the interrupt comes, the vCPU thread is then
      migrated to a new physical CPU, and in general the latency is horrible
      because the vCPU thread has to be scheduled back in.
      
      With this patch performance reaches 60-65% of bare metal and, more
      important, 99% of what you get if you use idle=poll in the guest.  This
      means that the tunable gets rid of this particular bottleneck, and more
      work can be done to improve performance in the kernel or QEMU.
      
      Of course there is some price to pay; every time an otherwise idle vCPUs
      is interrupted by an interrupt, it will poll unnecessarily and thus
      impose a little load on the host.  The above results were obtained with
      a mostly random value of the parameter (500000), and the load was around
      1.5-2.5% CPU usage on one of the host's core for each idle guest vCPU.
      
      The patch also adds a new stat, /sys/kernel/debug/kvm/halt_successful_poll,
      that can be used to tune the parameter.  It counts how many HLT
      instructions received an interrupt during the polling period; each
      successful poll avoids that Linux schedules the VCPU thread out and back
      in, and may also avoid a likely trip to C1 and back for the physical CPU.
      
      While the VM is idle, a Linux 4 VCPU VM halts around 10 times per second.
      Of these halts, almost all are failed polls.  During the benchmark,
      instead, basically all halts end within the polling period, except a more
      or less constant stream of 50 per second coming from vCPUs that are not
      running the benchmark.  The wasted time is thus very low.  Things may
      be slightly different for Windows VMs, which have a ~10 ms timer tick.
      
      The effect is also visible on Marcelo's recently-introduced latency
      test for the TSC deadline timer.  Though of course a non-RT kernel has
      awful latency bounds, the latency of the timer is around 8000-10000 clock
      cycles compared to 20000-120000 without setting halt_poll_ns.  For the TSC
      deadline timer, thus, the effect is both a smaller average latency and
      a smaller variance.
      Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      f7819512
  12. 02 Feb, 2015 1 commit
  13. 29 Jan, 2015 4 commits
  14. 28 Jan, 2015 1 commit
  15. 27 Jan, 2015 3 commits
    • Lorenzo Pieralisi's avatar
      arm64: kernel: remove ARM64_CPU_SUSPEND config option · af3cfdbf
      Lorenzo Pieralisi authored
      
      
      ARM64_CPU_SUSPEND config option was introduced to make code providing
      context save/restore selectable only on platforms requiring power
      management capabilities.
      
      Currently ARM64_CPU_SUSPEND depends on the PM_SLEEP config option which
      in turn is set by the SUSPEND config option.
      
      The introduction of CPU_IDLE for arm64 requires that code configured
      by ARM64_CPU_SUSPEND (context save/restore) should be compiled in
      in order to enable the CPU idle driver to rely on CPU operations
      carrying out context save/restore.
      
      The ARM64_CPUIDLE config option (ARM64 generic idle driver) is therefore
      forced to select ARM64_CPU_SUSPEND, even if there may be (ie PM_SLEEP)
      failed dependencies, which is not a clean way of handling the kernel
      configuration option.
      
      For these reasons, this patch removes the ARM64_CPU_SUSPEND config option
      and makes the context save/restore dependent on CPU_PM, which is selected
      whenever either SUSPEND or CPU_IDLE are configured, cleaning up dependencies
      in the process.
      
      This way, code previously configured through ARM64_CPU_SUSPEND is
      compiled in whenever a power management subsystem requires it to be
      present in the kernel (SUSPEND || CPU_IDLE), which is the behaviour
      expected on ARM64 kernels.
      
      The cpu_suspend and cpu_init_idle CPU operations are added only if
      CPU_IDLE is selected, since they are CPU_IDLE specific methods and
      should be grouped and defined accordingly.
      
      PSCI CPU operations are updated to reflect the introduced changes.
      Signed-off-by: default avatarLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
      Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
      Cc: Mark Rutland <mark.rutland@arm.com>
      Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      af3cfdbf
    • Catalin Marinas's avatar
      arm64: Remove asm/syscalls.h · 96486069
      Catalin Marinas authored
      
      
      This patch moves the sys_rt_sigreturn_wrapper prototype to
      arch/arm64/kernel/sys.c and removes the asm/syscalls.h header.
      Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      96486069
    • Catalin Marinas's avatar
      arm64: Implement the compat_sys_call_table in C · 0156411b
      Catalin Marinas authored
      
      
      Unlike the sys_call_table[], the compat one was implemented in sys32.S
      making it impossible to notice discrepancies between the number of
      compat syscalls and the __NR_compat_syscalls macro, the latter having to
      be defined in asm/unistd.h as including asm/unistd32.h would cause
      conflicts on __NR_* definitions. With this patch, incorrect
      __NR_compat_syscalls values will result in a build-time error.
      Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      Suggested-by: default avatarMark Rutland <mark.rutland@arm.com>
      Acked-by: default avatarMark Rutland <mark.rutland@arm.com>
      0156411b
  16. 23 Jan, 2015 7 commits
    • Will Deacon's avatar
      arm64: uapi: expose our struct ucontext to the uapi headers · 33b36543
      Will Deacon authored
      
      
      arm64 defines its own ucontext structure which is incompatible with the
      struct defined (and exposed to userspace by) the asm-generic headers.
      
      glibc carries its own struct definition that is compatible with the
      arm64 definition, but we should expose our format in the uapi headers in
      case other libraries want to make use of the ucontext pushed as part of
      an arm64 sigframe.
      
      This patch moves the arm64 asm/ucontext.h to the uapi headers, along
      with the necessary #include of linux/types.h.
      
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Marcus Shawcroft <marcus.shawcroft@arm.com>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      33b36543
    • Jiang Liu's avatar
      smp, ARM64: Kill SMP single function call interrupt · 0aaf0dae
      Jiang Liu authored
      Commit 9a46ad6d
      
       "smp: make smp_call_function_many() use logic
      similar to smp_call_function_single()" has unified the way to handle
      single and multiple cross-CPU function calls. Now only one interrupt
      is needed for architecture specific code to support generic SMP function
      call interfaces, so kill the redundant single function call interrupt.
      Signed-off-by: default avatarJiang Liu <jiang.liu@linux.intel.com>
      Acked-by: default avatarWill Deacon <will.deacon@arm.com>
      Cc: linux-arm-kernel@lists.infradead.org
      Cc: Arnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      0aaf0dae
    • Suzuki K. Poulose's avatar
      arm64: Emulate SETEND for AArch32 tasks · 2d888f48
      Suzuki K. Poulose authored
      
      
      Emulate deprecated 'setend' instruction for AArch32 bit tasks.
      
      	setend [le/be] - Sets the endianness of EL0
      
      On systems with CPUs which support mixed endian at EL0, the hardware
      support for the instruction can be enabled by setting the SCTLR_EL1.SED
      bit. Like the other emulated instructions it is controlled by an entry in
      /proc/sys/abi/. For more information see :
      	Documentation/arm64/legacy_instructions.txt
      
      The instruction is emulated by setting/clearing the SPSR_EL1.E bit, which
      will be reflected in the PSTATE.E in AArch32 context.
      
      This patch also restores the native endianness for the execution of signal
      handlers, since the process could have changed the endianness.
      
      Note: All CPUs on the system must have mixed endian support at EL0. Once the
      handler is registered, hotplugging a CPU which doesn't support mixed endian,
      could lead to unexpected results/behavior in applications.
      Signed-off-by: default avatarSuzuki K. Poulose <suzuki.poulose@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Punit Agrawal <punit.agrawal@arm.com>
      Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      2d888f48
    • Suzuki K. Poulose's avatar
      arm64: Consolidate hotplug notifier for instruction emulation · 736d474f
      Suzuki K. Poulose authored
      
      
      As of now each insn_emulation has a cpu hotplug notifier that
      enables/disables the CPU feature bit for the functionality. This
      patch re-arranges the code, such that there is only one notifier
      that runs through the list of registered emulation hooks and runs
      their corresponding set_hw_mode.
      
      We do nothing when a CPU is dying as we will set the appropriate bits
      as it comes back online based on the state of the hooks.
      Signed-off-by: default avatarMark Rutland <mark.rutland@arm.com>
      Signed-off-by: default avatarSuzuki K. Poulose <suzuki.poulose@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Punit Agrawal <punit.agrawal@arm.com>
      [catalin.marinas@arm.com: fix pr_warn compilation error]
      [catalin.marinas@arm.com: remove unnecessary "insn" check]
      Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      736d474f
    • Suzuki K. Poulose's avatar
      arm64: Track system support for mixed endian EL0 · 04597a65
      Suzuki K. Poulose authored
      
      
      This patch keeps track of the mixed endian EL0 support across
      the system and provides helper functions to export it. The status
      is a boolean indicating whether all the CPUs on the system supports
      mixed endian at EL0.
      Signed-off-by: default avatarSuzuki K. Poulose <suzuki.poulose@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      04597a65
    • Catalin Marinas's avatar
      arm64: Combine coherent and non-coherent swiotlb dma_ops · 9d3bfbb4
      Catalin Marinas authored
      
      
      Since dev_archdata now has a dma_coherent state, combine the two
      coherent and non-coherent operations and remove their declaration,
      together with set_dma_ops, from the arch dma-mapping.h file.
      Acked-by: default avatarWill Deacon <will.deacon@arm.com>
      Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      9d3bfbb4
    • Mark Rutland's avatar
      arm64: Fix overlapping VA allocations · aa03c428
      Mark Rutland authored
      PCI IO space was intended to be 16MiB, at 32MiB below MODULES_VADDR, but
      commit d1e6dc91
      
       ("arm64: Add architectural support for PCI")
      extended this to cover the full 32MiB. The final 8KiB of this 32MiB is
      also allocated for the fixmap, allowing for potential clashes between
      the two.
      
      This change was masked by assumptions in mem_init and the page table
      dumping code, which assumed the I/O space to be 16MiB long through
      seaparte hard-coded definitions.
      
      This patch changes the definition of the PCI I/O space allocation to
      live in asm/memory.h, along with the other VA space allocations. As the
      fixmap allocation depends on the number of fixmap entries, this is moved
      below the PCI I/O space allocation. Both the fixmap and PCI I/O space
      are guarded with 2MB of padding. Sites assuming the I/O space was 16MiB
      are moved over use new PCI_IO_{START,END} definitions, which will keep
      in sync with the size of the IO space (now restored to 16MiB).
      
      As a useful side effect, the use of the new PCI_IO_{START,END}
      definitions prevents a build issue in the dumping code due to a (now
      redundant) missing include of io.h for PCI_IOBASE.
      Signed-off-by: default avatarMark Rutland <mark.rutland@arm.com>
      Cc: Kees Cook <keescook@chromium.org>
      Cc: Laura Abbott <lauraa@codeaurora.org>
      Cc: Liviu Dudau <liviu.dudau@arm.com>
      Cc: Steve Capper <steve.capper@linaro.org>
      Cc: Will Deacon <will.deacon@arm.com>
      [catalin.marinas@arm.com: reorder FIXADDR and PCI_IO address_markers_idx enum]
      Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      aa03c428
  17. 22 Jan, 2015 3 commits
  18. 20 Jan, 2015 2 commits