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2016-03-25arch, ftrace: for KASAN put hard/soft IRQ entries into separate sectionsAlexander Potapenko1-0/+1
KASAN needs to know whether the allocation happens in an IRQ handler. This lets us strip everything below the IRQ entry point to reduce the number of unique stack traces needed to be stored. Move the definition of __irq_entry to <linux/interrupt.h> so that the users don't need to pull in <linux/ftrace.h>. Also introduce the __softirq_entry macro which is similar to __irq_entry, but puts the corresponding functions to the .softirqentry.text section. Signed-off-by: Alexander Potapenko <[email protected]> Acked-by: Steven Rostedt <[email protected]> Cc: Christoph Lameter <[email protected]> Cc: Pekka Enberg <[email protected]> Cc: David Rientjes <[email protected]> Cc: Joonsoo Kim <[email protected]> Cc: Andrey Konovalov <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Andrey Ryabinin <[email protected]> Cc: Konstantin Serebryany <[email protected]> Cc: Dmitry Chernenkov <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
2016-03-17Merge tag 'gpio-v4.6-1' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio Pull GPIO updates from Linus Walleij: "This is the bulk of GPIO changes for kernel v4.6. There is quite a lot of interesting stuff going on. The patches to other subsystems and arch-wide are ACKed as far as possible, though I consider things like per-arch <asm/gpio.h> as essentially a part of the GPIO subsystem so it should not be needed. Core changes: - The gpio_chip is now a *real device*. Until now the gpio chips were just piggybacking the parent device or (gasp) floating in space outside of the device model. We now finally make GPIO chips devices. The gpio_chip will create a gpio_device which contains a struct device, and this gpio_device struct is kept private. Anything that needs to be kept private from the rest of the kernel will gradually be moved over to the gpio_device. - As a result of making the gpio_device a real device, we have added resource management, so devm_gpiochip_add_data() will cut down on overhead and reduce code lines. A huge slew of patches convert almost all drivers in the subsystem to use this. - Building on making the GPIO a real device, we add the first step of a new userspace ABI: the GPIO character device. We take small steps here, so we first add a pure *information* ABI and the tool "lsgpio" that will list all GPIO devices on the system and all lines on these devices. We can now discover GPIOs properly from userspace. We still have not come up with a way to actually *use* GPIOs from userspace. - To encourage people to use the character device for the future, we have it always-enabled when using GPIO. The old sysfs ABI is still opt-in (and can be used in parallel), but is marked as deprecated. We will keep it around for the foreseeable future, but it will not be extended to cover ever more use cases. Cleanup: - Bjorn Helgaas removed a whole slew of per-architecture <asm/gpio.h> includes. This dates back to when GPIO was an opt-in feature and no shared library even existed: just a header file with proper prototypes was provided and all semantics were up to the arch to implement. These patches make the GPIO chip even more a proper device and cleans out leftovers of the old in-kernel API here and there. Still some cruft is left but it's very little now. - There is still some clamping of return values for .get() going on, but we now return sane values in the vast majority of drivers and the errorpath is sanitized. Some patches for powerpc, blackfin and unicore still drop in. - We continue to switch the ARM, MIPS, blackfin, m68k local GPIO implementations to use gpiochip_add_data() and cut down on code lines. - MPC8xxx is converted to use the generic GPIO helpers. - ATH79 is converted to use the generic GPIO helpers. New drivers: - WinSystems WS16C48 - Acces 104-DIO-48E - F81866 (a F7188x variant) - Qoric (a MPC8xxx variant) - TS-4800 - SPI serializers (pisosr): simple 74xx shift registers connected to SPI to obtain a dirt-cheap output-only GPIO expander. - Texas Instruments TPIC2810 - Texas Instruments TPS65218 - Texas Instruments TPS65912 - X-Gene (ARM64) standby GPIO controller" * tag 'gpio-v4.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (194 commits) Revert "Share upstreaming patches" gpio: mcp23s08: Fix clearing of interrupt. gpiolib: Fix comment referring to gpio_*() in gpiod_*() gpio: pca953x: Fix pca953x_gpio_set_multiple() on 64-bit gpio: xgene: Fix kconfig for standby GIPO contoller gpio: Add generic serializer DT binding gpio: uapi: use 0xB4 as ioctl() major gpio: tps65912: fix bad merge Revert "gpio: lp3943: Drop pin_used and lp3943_gpio_request/lp3943_gpio_free" gpio: omap: drop dev field from gpio_bank structure gpio: mpc8xxx: Slightly update the code for better readability gpio: mpc8xxx: Remove *read_reg and *write_reg from struct mpc8xxx_gpio_chip gpio: mpc8xxx: Fixup setting gpio direction output gpio: mcp23s08: Add support for mcp23s18 dt-bindings: gpio: altera: Fix altr,interrupt-type property gpio: add driver for MEN 16Z127 GPIO controller gpio: lp3943: Drop pin_used and lp3943_gpio_request/lp3943_gpio_free gpio: timberdale: Switch to devm_ioremap_resource() gpio: ts4800: Add IMX51 dependency gpiolib: rewrite gpiodev_add_to_list ...
2016-03-15Merge branch 'smp-hotplug-for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull cpu hotplug updates from Thomas Gleixner: "This is the first part of the ongoing cpu hotplug rework: - Initial implementation of the state machine - Runs all online and prepare down callbacks on the plugged cpu and not on some random processor - Replaces busy loop waiting with completions - Adds tracepoints so the states can be followed" More detailed commentary on this work from an earlier email: "What's wrong with the current cpu hotplug infrastructure? - Asymmetry The hotplug notifier mechanism is asymmetric versus the bringup and teardown. This is mostly caused by the notifier mechanism. - Largely undocumented dependencies While some notifiers use explicitely defined notifier priorities, we have quite some notifiers which use numerical priorities to express dependencies without any documentation why. - Control processor driven Most of the bringup/teardown of a cpu is driven by a control processor. While it is understandable, that preperatory steps, like idle thread creation, memory allocation for and initialization of essential facilities needs to be done before a cpu can boot, there is no reason why everything else must run on a control processor. Before this patch series, bringup looks like this: Control CPU Booting CPU do preparatory steps kick cpu into life do low level init sync with booting cpu sync with control cpu bring the rest up - All or nothing approach There is no way to do partial bringups. That's something which is really desired because we waste e.g. at boot substantial amount of time just busy waiting that the cpu comes to life. That's stupid as we could very well do preparatory steps and the initial IPI for other cpus and then go back and do the necessary low level synchronization with the freshly booted cpu. - Minimal debuggability Due to the notifier based design, it's impossible to switch between two stages of the bringup/teardown back and forth in order to test the correctness. So in many hotplug notifiers the cancel mechanisms are either not existant or completely untested. - Notifier [un]registering is tedious To [un]register notifiers we need to protect against hotplug at every callsite. There is no mechanism that bringup/teardown callbacks are issued on the online cpus, so every caller needs to do it itself. That also includes error rollback. What's the new design? The base of the new design is a symmetric state machine, where both the control processor and the booting/dying cpu execute a well defined set of states. Each state is symmetric in the end, except for some well defined exceptions, and the bringup/teardown can be stopped and reversed at almost all states. So the bringup of a cpu will look like this in the future: Control CPU Booting CPU do preparatory steps kick cpu into life do low level init sync with booting cpu sync with control cpu bring itself up The synchronization step does not require the control cpu to wait. That mechanism can be done asynchronously via a worker or some other mechanism. The teardown can be made very similar, so that the dying cpu cleans up and brings itself down. Cleanups which need to be done after the cpu is gone, can be scheduled asynchronously as well. There is a long way to this, as we need to refactor the notion when a cpu is available. Today we set the cpu online right after it comes out of the low level bringup, which is not really correct. The proper mechanism is to set it to available, i.e. cpu local threads, like softirqd, hotplug thread etc. can be scheduled on that cpu, and once it finished all booting steps, it's set to online, so general workloads can be scheduled on it. The reverse happens on teardown. First thing to do is to forbid scheduling of general workloads, then teardown all the per cpu resources and finally shut it off completely. This patch series implements the basic infrastructure for this at the core level. This includes the following: - Basic state machine implementation with well defined states, so ordering and prioritization can be expressed. - Interfaces to [un]register state callbacks This invokes the bringup/teardown callback on all online cpus with the proper protection in place and [un]installs the callbacks in the state machine array. For callbacks which have no particular ordering requirement we have a dynamic state space, so that drivers don't have to register an explicit hotplug state. If a callback fails, the code automatically does a rollback to the previous state. - Sysfs interface to drive the state machine to a particular step. This is only partially functional today. Full functionality and therefor testability will be achieved once we converted all existing hotplug notifiers over to the new scheme. - Run all CPU_ONLINE/DOWN_PREPARE notifiers on the booting/dying processor: Control CPU Booting CPU do preparatory steps kick cpu into life do low level init sync with booting cpu sync with control cpu wait for boot bring itself up Signal completion to control cpu In a previous step of this work we've done a full tree mechanical conversion of all hotplug notifiers to the new scheme. The balance is a net removal of about 4000 lines of code. This is not included in this series, as we decided to take a different approach. Instead of mechanically converting everything over, we will do a proper overhaul of the usage sites one by one so they nicely fit into the symmetric callback scheme. I decided to do that after I looked at the ugliness of some of the converted sites and figured out that their hotplug mechanism is completely buggered anyway. So there is no point to do a mechanical conversion first as we need to go through the usage sites one by one again in order to achieve a full symmetric and testable behaviour" * 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits) cpu/hotplug: Document states better cpu/hotplug: Fix smpboot thread ordering cpu/hotplug: Remove redundant state check cpu/hotplug: Plug death reporting race rcu: Make CPU_DYING_IDLE an explicit call cpu/hotplug: Make wait for dead cpu completion based cpu/hotplug: Let upcoming cpu bring itself fully up arch/hotplug: Call into idle with a proper state cpu/hotplug: Move online calls to hotplugged cpu cpu/hotplug: Create hotplug threads cpu/hotplug: Split out the state walk into functions cpu/hotplug: Unpark smpboot threads from the state machine cpu/hotplug: Move scheduler cpu_online notifier to hotplug core cpu/hotplug: Implement setup/removal interface cpu/hotplug: Make target state writeable cpu/hotplug: Add sysfs state interface cpu/hotplug: Hand in target state to _cpu_up/down cpu/hotplug: Convert the hotplugged cpu work to a state machine cpu/hotplug: Convert to a state machine for the control processor cpu/hotplug: Add tracepoints ...
2016-03-15Merge branch 'irq-core-for-linus' of ↵Linus Torvalds5-6/+141
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq updates from Thomas Gleixner: "The 4.6 pile of irq updates contains: - Support for IPI irqdomains to support proper integration of IPIs to and from coprocessors. The first user of this new facility is MIPS. The relevant MIPS patches come with the core to avoid merge ordering issues and have been acked by Ralf. - A new command line option to set the default interrupt affinity mask at boot time. - Support for some more new ARM and MIPS interrupt controllers: tango, alpine-msix and bcm6345-l1 - Two small cleanups for x86/apic which we merged into irq/core to avoid yet another branch in x86 with two tiny commits. - The usual set of updates, cleanups in drivers/irqchip. Mostly in the area of ARM-GIC, arada-37-xp and atmel chips. Nothing outstanding here" * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (56 commits) irqchip/irq-alpine-msi: Release the correct domain on error irqchip/mxs: Fix error check of of_io_request_and_map() irqchip/sunxi-nmi: Fix error check of of_io_request_and_map() genirq: Export IRQ functions for module use irqchip/gic/realview: Support more RealView DCC variants Documentation/bindings: Document the Alpine MSIX driver irqchip: Add the Alpine MSIX interrupt controller irqchip/gic-v3: Always return IRQ_SET_MASK_OK_DONE in gic_set_affinity irqchip/gic-v3-its: Mark its_init() and its children as __init irqchip/gic-v3: Remove gic_root_node variable from the ITS code irqchip/gic-v3: ACPI: Add redistributor support via GICC structures irqchip/gic-v3: Add ACPI support for GICv3/4 initialization irqchip/gic-v3: Refactor gic_of_init() for GICv3 driver x86/apic: Deinline _flat_send_IPI_mask, save ~150 bytes x86/apic: Deinline __default_send_IPI_*, save ~200 bytes dt-bindings: interrupt-controller: Add SoC-specific compatible string to Marvell ODMI irqchip/mips-gic: Add new DT property to reserve IPIs MIPS: Delete smp-gic.c MIPS: Make smp CMP, CPS and MT use the new generic IPI functions MIPS: Add generic SMP IPI support ...
2016-03-14Merge branch 'core-resources-for-linus' of ↵Linus Torvalds1-4/+6
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull ram resource handling changes from Ingo Molnar: "Core kernel resource handling changes to support NVDIMM error injection. This tree introduces a new I/O resource type, IORESOURCE_SYSTEM_RAM, for System RAM while keeping the current IORESOURCE_MEM type bit set for all memory-mapped ranges (including System RAM) for backward compatibility. With this resource flag it no longer takes a strcmp() loop through the resource tree to find "System RAM" resources. The new resource type is then used to extend ACPI/APEI error injection facility to also support NVDIMM" * 'core-resources-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: ACPI/EINJ: Allow memory error injection to NVDIMM resource: Kill walk_iomem_res() x86/kexec: Remove walk_iomem_res() call with GART type x86, kexec, nvdimm: Use walk_iomem_res_desc() for iomem search resource: Add walk_iomem_res_desc() memremap: Change region_intersects() to take @flags and @desc arm/samsung: Change s3c_pm_run_res() to use System RAM type resource: Change walk_system_ram() to use System RAM type drivers: Initialize resource entry to zero xen, mm: Set IORESOURCE_SYSTEM_RAM to System RAM kexec: Set IORESOURCE_SYSTEM_RAM for System RAM arch: Set IORESOURCE_SYSTEM_RAM flag for System RAM ia64: Set System RAM type and descriptor x86/e820: Set System RAM type and descriptor resource: Add I/O resource descriptor resource: Handle resource flags properly resource: Add System RAM resource type
2016-03-13MIPS: smp.c: Fix uninitialised temp_foreign_mapJames Hogan1-0/+1
When calculate_cpu_foreign_map() recalculates the cpu_foreign_map cpumask it uses the local variable temp_foreign_map without initialising it to zero. Since the calculation only ever sets bits in this cpumask any existing bits at that memory location will remain set and find their way into cpu_foreign_map too. This could potentially lead to cache operations suboptimally doing smp calls to multiple VPEs in the same core, even though the VPEs share primary caches. Therefore initialise temp_foreign_map using cpumask_clear() before use. Fixes: cccf34e9411c ("MIPS: c-r4k: Fix cache flushing for MT cores") Signed-off-by: James Hogan <[email protected]> Cc: Paul Burton <[email protected]> Cc: [email protected] Patchwork: https://patchwork.linux-mips.org/patch/12759/ Signed-off-by: Ralf Baechle <[email protected]>
2016-03-08Merge branch 'linus' into irq/core, to pick up fixesIngo Molnar11-34/+23
Signed-off-by: Ingo Molnar <[email protected]>
2016-03-04MIPS: traps: Fix SIGFPE information leak from `do_ov' and `do_trap_or_bp'Maciej W. Rozycki1-7/+6
Avoid sending a partially initialised `siginfo_t' structure along SIGFPE signals issued from `do_ov' and `do_trap_or_bp', leading to information leaking from the kernel stack. Signed-off-by: Maciej W. Rozycki <[email protected]> Cc: [email protected] Signed-off-by: Ralf Baechle <[email protected]>
2016-03-04Merge tag 'v4.5-rc6' into core/resources, to resolve conflictIngo Molnar9-25/+15
Signed-off-by: Ingo Molnar <[email protected]>
2016-03-01arch/hotplug: Call into idle with a proper stateThomas Gleixner1-1/+1
Let the non boot cpus call into idle with the corresponding hotplug state, so the hotplug core can handle the further bringup. That's a first step to convert the boot side of the hotplugged cpus to do all the synchronization with the other side through the state machine. For now it'll only start the hotplug thread and kick the full bringup of the cpu. Signed-off-by: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: Rik van Riel <[email protected]> Cc: Rafael Wysocki <[email protected]> Cc: "Srivatsa S. Bhat" <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Arjan van de Ven <[email protected]> Cc: Sebastian Siewior <[email protected]> Cc: Rusty Russell <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Tejun Heo <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Paul McKenney <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Paul Turner <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Thomas Gleixner <[email protected]>
2016-02-29MIPS: Avoid variant of .type unsupported by LLVM AssemblerDaniel Sanders2-2/+2
The target independent parts of the LLVM Lexer considers 'fault@function' to be a single token representing the 'fault' symbol with a 'function' modifier. However, this is not the case in the .type directive where 'function' refers to STT_FUNC from the ELF standard. Although GAS accepts it, '.type symbol@function' is an undocumented form of this directive. The documentation specifies a comma between the symbol and '@function'. Signed-off-by: Scott Egerton <[email protected]> Signed-off-by: Daniel Sanders <[email protected]> Reviewed-by: Maciej W. Rozycki <[email protected]> Cc: Paul Burton <[email protected]> Cc: Leonid Yegoshin <[email protected]> Cc: [email protected] Patchwork: https://patchwork.linux-mips.org/patch/12587/ Signed-off-by: Ralf Baechle <[email protected]>
2016-02-25MIPS: Delete smp-gic.cQais Yousef1-1/+0
We now have a generic IPI layer that will use GIC automatically if it's compiled in. Signed-off-by: Qais Yousef <[email protected]> Acked-by: Ralf Baechle <[email protected]> Cc: <[email protected]> Cc: <[email protected]> Cc: <[email protected]> Cc: <[email protected]> Cc: <[email protected]> Cc: Qais Yousef <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Thomas Gleixner <[email protected]>
2016-02-25MIPS: Make smp CMP, CPS and MT use the new generic IPI functionsQais Yousef3-5/+5
This commit does several things to avoid breaking bisectability. 1- Remove IPI init code from irqchip/mips-gic 2- Implement the new irqchip->send_ipi() in irqchip/mips-gic 3- Select GENERIC_IRQ_IPI Kconfig symbol for MIPS_GIC 4- Change MIPS SMP to use the generic IPI implementation Only the SMP variants that use GIC were converted as it's the only irqchip that will have the support for generic IPI for now. Signed-off-by: Qais Yousef <[email protected]> Acked-by: Ralf Baechle <[email protected]> Cc: <[email protected]> Cc: <[email protected]> Cc: <[email protected]> Cc: <[email protected]> Cc: <[email protected]> Cc: Qais Yousef <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Thomas Gleixner <[email protected]>
2016-02-25MIPS: Add generic SMP IPI supportQais Yousef1-0/+136
Use the new generic IPI layer to provide generic SMP IPI support if the irqchip supports it. Signed-off-by: Qais Yousef <[email protected]> Acked-by: Ralf Baechle <[email protected]> Cc: <[email protected]> Cc: <[email protected]> Cc: <[email protected]> Cc: <[email protected]> Cc: <[email protected]> Cc: Qais Yousef <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Thomas Gleixner <[email protected]>
2016-02-19MIPS: txx9: switch to gpiochip_add_data()Linus Walleij1-2/+2
We're planning to remove the gpiochip_add() function to swith to gpiochip_add_data() with NULL for data argument. Cc: [email protected] Acked-by: Ralf Baechle <[email protected]> Signed-off-by: Linus Walleij <[email protected]>
2016-02-11mips: Differentiate between 32 and 64 bit ELF headerDaniel Wagner2-2/+2
Depending on the configuration either the 32 or 64 bit version of elf_check_arch() is defined. parse_crash_elf{32|64}_headers() does some basic verification of the ELF header via vmcore_elf{32|64}_check_arch() which happen to map to elf_check_arch(). Since the implementation 32 and 64 bit version of elf_check_arch() differ, we use the wrong type: In file included from include/linux/elf.h:4:0, from fs/proc/vmcore.c:13: fs/proc/vmcore.c: In function 'parse_crash_elf64_headers': >> arch/mips/include/asm/elf.h:228:23: error: initialization from incompatible pointer type [-Werror=incompatible-pointer-types] struct elfhdr *__h = (hdr); \ ^ include/linux/crash_dump.h:41:37: note: in expansion of macro 'elf_check_arch' #define vmcore_elf64_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x)) ^ fs/proc/vmcore.c:1015:4: note: in expansion of macro 'vmcore_elf64_check_arch' !vmcore_elf64_check_arch(&ehdr) || ^ Therefore, we rather define vmcore_elf{32|64}_check_arch() as a basic machine check and use it also in binfm_elf?32.c as well. Signed-off-by: Daniel Wagner <[email protected]> Suggested-by: Maciej W. Rozycki <[email protected]> Reviewed-by: Maciej W. Rozycki <[email protected]> Reported-by: Fengguang Wu <[email protected]> Cc: [email protected] Cc: [email protected] Patchwork: https://patchwork.linux-mips.org/patch/12529/ Signed-off-by: Ralf Baechle <[email protected]>
2016-02-09MIPS: Fix early CM probingPaul Burton1-0/+1
Commit c014d164f21d ("MIPS: Add platform callback before initializing the L2 cache") added a platform_early_l2_init function in order to allow platforms to probe for the CM before L2 initialisation is performed, so that CM GCRs are available to mips_sc_probe. That commit actually fails to do anything useful, since it checks mips_cm_revision to determine whether it should call mips_cm_probe but the result of mips_cm_revision will always be 0 until mips_cm_probe has been called. Thus the "early" mips_cm_probe call never occurs. Fix this & drop the useless weak platform_early_l2_init function by simply calling mips_cm_probe from setup_arch. For platforms that don't select CONFIG_MIPS_CM this will be a no-op, and for those that do it removes the requirement for them to call mips_cm_probe manually (although doing so isn't harmful for now). Signed-off-by: Paul Burton <[email protected]> Reviewed-by: Alexander Sverdlin <[email protected]> Cc: Andrzej Hajda <[email protected]> Cc: Aaro Koskinen <[email protected]> Cc: Masahiro Yamada <[email protected]> Cc: Rob Herring <[email protected]> Cc: Peter Hurley <[email protected]> Cc: Leonid Yegoshin <[email protected]> Cc: Jaedon Shin <[email protected]> Cc: James Hogan <[email protected]> Cc: Jonas Gorski <[email protected]> Cc: Markos Chandras <[email protected]> Cc: [email protected] Cc: [email protected] Patchwork: https://patchwork.linux-mips.org/patch/12475/ Signed-off-by: Ralf Baechle <[email protected]>
2016-02-05MIPS: Wire up copy_file_range syscall.Ralf Baechle4-0/+4
Signed-off-by: Ralf Baechle <[email protected]>
2016-02-02MIPS: traps.c: Correct microMIPS RDHWR emulationMaciej W. Rozycki1-4/+5
Fix the code to fetch and decode the whole 32-bit instruction. This only really matters with the `noulri' kernel parameter as all microMIPS processors are supposed to have all the hardware registers we support. Signed-off-by: Maciej W. Rozycki <[email protected]> Cc: [email protected] Patchwork: https://patchwork.linux-mips.org/patch/12281/ Signed-off-by: Ralf Baechle <[email protected]>
2016-02-02MIPS: traps.c: Don't emulate RDHWR in the CpU #0 exception handlerMaciej W. Rozycki1-15/+1
In the regular MIPS instruction set RDHWR is encoded with the SPECIAL3 (011111) major opcode. Therefore it cannot trigger the CpU (Coprocessor Unusable) exception, and certainly not for coprocessor 0, as the opcode does not overlap with any of the older ISA reservations, i.e. LWC0 (110000), SWC0 (111000), LDC0 (110100) or SDC0 (111100). The closest match might be SDC3 (111111), possibly causing a CpU #3 exception, however our code does not handle it anyway. A quick check with a MIPS I and a MIPS III processor: CPU0 revision is: 00000220 (R3000) CPU0 revision is: 00000440 (R4400SC) indeed indicates that the RI (Reserved Instruction) exception is triggered. It's only LL and SC that require emulation in the CpU #0 exception handler as they reuse the LWC0 and SWC0 opcodes respectively. In the microMIPS instruction set RDHWR is mandatory and triggering the RI exception is required on unimplemented or disabled register accesses. Therefore emulating the microMIPS instruction in the CpU #0 exception handler is not required either. Signed-off-by: Maciej W. Rozycki <[email protected]> Cc: [email protected] Patchwork: https://patchwork.linux-mips.org/patch/12280/ Signed-off-by: Ralf Baechle <[email protected]>
2016-02-01MIPS: Properly disable FPU in start_thread()James Hogan1-4/+2
start_thread() (called for execve(2)) clears the TIF_USEDFPU flag without atomically disabling the FPU. With a preemptive kernel, an unfortunately timed preemption after this could result in another task (or KVM guest) being scheduled in with the FPU still enabled, since lose_fpu_inatomic() only turns it off if TIF_USEDFPU is set. Use lose_fpu(0) instead of the separate FPU / MSA management, which should do the right thing (drop FPU properly and atomically without saving state) and will be more future proof. Signed-off-by: James Hogan <[email protected]> Reviewed-by: Paul Burton <[email protected]> Cc: [email protected] Patchwork: https://patchwork.linux-mips.org/patch/12302/ Signed-off-by: Ralf Baechle <[email protected]>
2016-01-30arch: Set IORESOURCE_SYSTEM_RAM flag for System RAMToshi Kani1-4/+6
Set IORESOURCE_SYSTEM_RAM in flags of resource ranges with "System RAM", "Kernel code", "Kernel data", and "Kernel bss". Note that: - IORESOURCE_SYSRAM (i.e. modifier bit) is set in flags when IORESOURCE_MEM is already set. IORESOURCE_SYSTEM_RAM is defined as (IORESOURCE_MEM|IORESOURCE_SYSRAM). - Some archs do not set 'flags' for children nodes, such as "Kernel code". This patch does not change 'flags' in this case. Signed-off-by: Toshi Kani <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Luis R. Rodriguez <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Toshi Kani <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: linux-mm <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
2016-01-24Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linusLinus Torvalds9-74/+291
Pull MIPS updates from Ralf Baechle: "This is the main pull request for MIPS for 4.5 plus some 4.4 fixes. The executive summary: - ATH79 platform improvments, use DT bindings for the ATH79 USB PHY. - Avoid useless rebuilds for zboot. - jz4780: Add NEMC, BCH and NAND device tree nodes - Initial support for the MicroChip's DT platform. As all the device drivers are missing this is still of limited use. - Some Loongson3 cleanups. - The unavoidable whitespace polishing. - Reduce clock skew when synchronizing the CPU cycle counters on CPU startup. - Add MIPS R6 fixes. - Lots of cleanups across arch/mips as fallout from KVM. - Lots of minor fixes and changes for IEEE 754-2008 support to the FPU emulator / fp-assist software. - Minor Ralink, BCM47xx and bcm963xx platform support improvments. - Support SMP on BCM63168" * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (84 commits) MIPS: zboot: Add support for serial debug using the PROM MIPS: zboot: Avoid useless rebuilds MIPS: BMIPS: Enable ARCH_WANT_OPTIONAL_GPIOLIB MIPS: bcm63xx: nvram: Remove unused bcm63xx_nvram_get_psi_size() function MIPS: bcm963xx: Update bcm_tag field image_sequence MIPS: bcm963xx: Move extended flash address to bcm_tag header file MIPS: bcm963xx: Move Broadcom BCM963xx image tag data structure MIPS: bcm63xx: nvram: Use nvram structure definition from header file MIPS: bcm963xx: Add Broadcom BCM963xx board nvram data structure MAINTAINERS: Add KVM for MIPS entry MIPS: KVM: Add missing newline to kvm_err() MIPS: Move KVM specific opcodes into asm/inst.h MIPS: KVM: Use cacheops.h definitions MIPS: Break down cacheops.h definitions MIPS: Use EXCCODE_ constants with set_except_vector() MIPS: Update trap codes MIPS: Move Cause.ExcCode trap codes to mipsregs.h MIPS: KVM: Make kvm_mips_{init,exit}() static MIPS: KVM: Refactor added offsetof()s MIPS: KVM: Convert EXPORT_SYMBOL to _GPL ...
2016-01-24Merge branch '4.4-fixes' into mips-for-linux-nextRalf Baechle2-1/+4
2016-01-24MIPS: Use EXCCODE_ constants with set_except_vector()James Hogan2-30/+30
The first argument to set_except_vector is the ExcCode, which we now have definitions for. Lets make use of them. Signed-off-by: James Hogan <[email protected]> Cc: Paolo Bonzini <[email protected]> Cc: Gleb Natapov <[email protected]> Cc: [email protected] Cc: [email protected] Patchwork: https://patchwork.linux-mips.org/patch/11894/ Signed-off-by: Ralf Baechle <[email protected]>
2016-01-24MIPS: ptrace: Drop cp0_tcstatus from regoffset_table[]James Hogan1-3/+0
The cp0_tcstatus member of struct pt_regs was removed along with the rest of SMTC in v3.16, commit b633648c5ad3 ("MIPS: MT: Remove SMTC support"), however recent uprobes support in v4.3 added back a reference to it in the regoffset_table[] in ptrace.c. Remove it. Signed-off-by: James Hogan <[email protected]> Fixes: 40e084a506eb ("MIPS: Add uprobes support.") Cc: [email protected] Patchwork: https://patchwork.linux-mips.org/patch/11920/ Signed-off-by: Ralf Baechle <[email protected]>
2016-01-24MIPS: TXx9: Be sure to clamp return valueLinus Walleij1-1/+1
As we want gpio_chip .get() calls to be able to return negative error codes and propagate to drivers, we need to go over all drivers and make sure their return values are clamped to [0,1]. We do this by using the ret = !!(val) design pattern. Signed-off-by: Linus Walleij <[email protected]> Cc: [email protected] Cc: [email protected] Patchwork: https://patchwork.linux-mips.org/patch/11923/ Signed-off-by: Ralf Baechle <[email protected]>
2016-01-24MIPS: Fix macro typoJaedon Shin1-1/+1
Change the CONFIG_MIPS_CMDLINE_EXTEND to CONFIG_MIPS_CMDLINE_DTB_EXTEND to resolve the EXTEND_WITH_PROM macro. Signed-off-by: Jaedon Shin <[email protected]> Fixes: 2024972ef533 ("MIPS: Make the kernel arguments from dtb available") Reviewed-by: Alexander Sverdlin <[email protected]> Cc: Jonas Gorski <[email protected]> Cc: Masahiro Yamada <[email protected]> Cc: Paul Burton <[email protected]> Cc: Aaro Koskinen <[email protected]> Cc: [email protected] Patchwork: https://patchwork.linux-mips.org/patch/11909/ Signed-off-by: Ralf Baechle <[email protected]>
2016-01-24MIPS: smp-cps: Ensure secondary cores start with EVA disabledMatt Redfearn1-0/+3
The kernel currently assumes that a core will start up in legacy mode using the exception base provided through the CM GCR registers. If a core has been configured in hardware to start in EVA mode, these assumptions will fail. This patch ensures that secondary cores are initialized to meet these assumptions. Signed-off-by: Matt Redfearn <[email protected]> Reviewed-by: Paul Burton <[email protected]> Cc: [email protected] Patchwork: https://patchwork.linux-mips.org/patch/11907/ Signed-off-by: Ralf Baechle <[email protected]>
2016-01-24MIPS: sync-r4k: reduce skew while synchronizationHuacai Chen1-24/+8
While synchronization, count register will go backwards for the master. If synchronise_count_master() runs before synchronise_count_slave(), skew becomes even more. The skew is very harmful for CPU hotplug (CPU0 do synchronization with CPU1, then CPU0 do synchronization with CPU2 and CPU0's count goes backwards, so it will be out of sync with CPU1). After the commit cf9bfe55f24973a8f40e2 (MIPS: Synchronize MIPS count one CPU at a time), we needn't evaluate count_reference at the beginning of synchronise_count_master() any more. Thus, we evaluate the initcount (It seems like count_reference is redundant) in the 2nd loop. Since we write the count register in the last loop, we don't need additional barriers (the existing memory barriers are enough). Moreover, I think we loop 3 times is enough to get a primed instruction cache, this can also get less skew than looping 5 times. Comments are also updated in this patch. Signed-off-by: Huacai Chen <[email protected]> Cc: Aurelien Jarno <[email protected]> Cc: Steven J. Hill <[email protected]> Cc: [email protected] Cc: Fuxin Zhang <[email protected]> Cc: Zhangjin Wu <[email protected]> Patchwork: https://patchwork.linux-mips.org/patch/12163/ Signed-off-by: Ralf Baechle <[email protected]>
2016-01-20MIPS: Add IEEE Std 754 conformance mode selectionMaciej W. Rozycki2-14/+103
Add an `ieee754=' kernel parameter to control IEEE Std 754 conformance mode. Use separate flags copied from the respective CPU feature flags, and adjusted according to the conformance mode selected, to make binaries requesting individual NaN encoding modes accepted or rejected as needed. Update the initial setting for FCSR and, in the full FPU emulation mode, its read-only mask accordingly. Accept the mode selection requested for legacy processors as well. As with the EF_MIPS_NAN2008 ELF file header flag adjust both ABS2008 and NAN2008 bits at the same time, to match the choice made for hardware currently implemented. Signed-off-by: Maciej W. Rozycki <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Matthew Fortune <[email protected]> Cc: [email protected] Cc: [email protected] Patchwork: https://patchwork.linux-mips.org/patch/11481/ Signed-off-by: Ralf Baechle <[email protected]>
2016-01-20MIPS: Determine the presence of IEEE Std 754-2008 featuresMaciej W. Rozycki1-2/+74
Determine the presence of and the amount of control available over IEEE Std 754-2008 features. In the case of a hardware FPU being used examine the FIR register for the presence of the HAS2008 bit and then the FCSR register for the writability of the ABS2008 and NAN2008 bits and the hardwired state of each of these bits if read-only. Update the initial FCSR contents used for threads and the FCSR writability mask accordingly. For full FPU emulation and MIPS32 or MIPS64 processors make the FCSR ABS2008 and NAN2008 bits writable. Signed-off-by: Maciej W. Rozycki <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Matthew Fortune <[email protected]> Cc: [email protected] Cc: [email protected] Patchwork: https://patchwork.linux-mips.org/patch/11480/ Signed-off-by: Ralf Baechle <[email protected]>
2016-01-20MIPS: ELF: Interpret the NAN2008 file header flagMaciej W. Rozycki1-0/+56
Handle the EF_MIPS_NAN2008 ELF file header flag and refuse execution where there is no support in the FPU for the NaN encoding mode requested by a binary invoked. Ensure that the setting of the bit in the binary matches one in any intepreter used. Set the thread's initial FCSR contents according to the value of the EF_MIPS_NAN2008. Set the values of the FCSR ABS2008 and NAN2008 bits both to the same value if possible, to take the approach taken with existing FPU hardware into account. As of now all implementations have both bits hardwired to the same value, that is both are fixed at 0 or both are fixed at 1, even though the architecture allows for implementations where the amount of control implemented with each of these two individual bits is independent of each other. Signed-off-by: Maciej W. Rozycki <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Matthew Fortune <[email protected]> Cc: [email protected] Cc: [email protected] Patchwork: https://patchwork.linux-mips.org/patch/11479/ Signed-off-by: Ralf Baechle <[email protected]>
2016-01-20ELF: Also pass any interpreter's file header to `arch_check_elf'Maciej W. Rozycki1-1/+1
Also pass any interpreter's file header to `arch_check_elf' so that any architecture handler can have a look at it if needed. Signed-off-by: Maciej W. Rozycki <[email protected]> Acked-by: Andrew Morton <[email protected]> Acked-by: Al Viro <[email protected]> Cc: Matthew Fortune <[email protected]> Cc: [email protected] Cc: [email protected] Patchwork: https://patchwork.linux-mips.org/patch/11478/ Signed-off-by: Ralf Baechle <[email protected]>
2016-01-20MIPS: math-emu: Add IEEE Std 754-2008 NaN encoding emulationMaciej W. Rozycki1-0/+2
Implement IEEE Std 754-2008 NaN encoding wired to the state of the FCSR.NAN2008 bit. Make the interpretation of the quiet bit in NaN data as follows: * in the legacy mode originally defined by the MIPS architecture the value of 1 denotes an sNaN whereas the value of 0 denotes a qNaN, * in the 2008 mode introduced with revision 5 of the MIPS architecture the value of 0 denotes an sNaN whereas the value of 1 denotes a qNaN, following the definition of the preferred NaN encoding introduced with IEEE Std 754-2008. In the 2008 mode, following the requirement of the said standard, quiet an sNaN where needed by setting the quiet bit to 1 and leaving all the NaN payload bits unchanged. Update format conversion operations according to the rules set by IEEE Std 754-2008 and the MIPS architecture. Specifically: * propagate NaN payload bits through conversions between floating-point formats such that as much information as possible is preserved and specifically a conversion from a narrower format to a wider format and then back to the original format does not change a qNaN payload in any way, * conversions from a floating-point to an integer format where the source is a NaN, infinity or a value that would convert to an integer outside the range of the result format produce, under the default exception handling, the respective values defined by the MIPS architecture. In full FPU emulation set the FIR.HAS2008 bit to 1, however do not make any further FCSR bits writable. Signed-off-by: Maciej W. Rozycki <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Matthew Fortune <[email protected]> Cc: [email protected] Cc: [email protected] Patchwork: https://patchwork.linux-mips.org/patch/11477/ Signed-off-by: Ralf Baechle <[email protected]>
2016-01-20MIPS: Define the legacy-NaN and 2008-NaN featuresMaciej W. Rozycki1-0/+2
Allocate CPU option bits and define macros for the legacy-NaN and 2008-NaN IEEE Std 754 MIPS architecture features. Unconditionally mark the legacy-NaN feature as present across hardware and emulated floating-point configurations. Signed-off-by: Maciej W. Rozycki <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Matthew Fortune <[email protected]> Cc: [email protected] Cc: [email protected] Patchwork: https://patchwork.linux-mips.org/patch/11475/ Signed-off-by: Ralf Baechle <[email protected]>
2016-01-20MIPS: Use a union to access the ELF file headerMaciej W. Rozycki1-14/+26
Rewrite `arch_elf_pt_proc' and `arch_check_elf' using a union to access the ELF file header. Signed-off-by: Maciej W. Rozycki <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Matthew Fortune <[email protected]> Cc: [email protected] Cc: [email protected] Patchwork: https://patchwork.linux-mips.org/patch/11474/ Signed-off-by: Ralf Baechle <[email protected]>
2016-01-14Merge branch 'for-linus' of ↵Linus Torvalds1-3/+3
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching Pull livepatching updates from Jiri Kosina: - RO/NX attribute fixes for patch module relocations from Josh Poimboeuf. As part of this effort, module.c has been cleaned up as well and livepatching is piggy-backing on this cleanup. Rusty is OK with this whole lot going through livepatching tree. - symbol disambiguation support from Chris J Arges. That series is also Reviewed-by: Miroslav Benes <[email protected]> but this came in only after I've alredy pushed out. Didn't want to rebase because of that, hence I am mentioning it here. - symbol lookup fix from Miroslav Benes * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching: livepatch: Cleanup module page permission changes module: keep percpu symbols in module's symtab module: clean up RO/NX handling. module: use a structure to encapsulate layout. gcov: use within_module() helper. module: Use the same logic for setting and unsetting RO/NX livepatch: function,sympos scheme in livepatch sysfs directory livepatch: add sympos as disambiguator field to klp_reloc livepatch: add old_sympos as disambiguator field to klp_func
2015-12-22MIPS: CPS: drop .set mips64r2 directivesPaul Burton1-2/+0
Commit 977e043d5ea1 ("MIPS: kernel: cps-vec: Replace mips32r2 ISA level with mips64r2") leads to .set mips64r2 directives being present in 32 bit (ie. CONFIG_32BIT=y) kernels. This is incorrect & leads to MIPS64 instructions being emitted by the assembler when expanding pseudo-instructions. For example the "move" instruction can legitimately be expanded to a "daddu". This causes problems when the kernel is run on a MIPS32 CPU, as CONFIG_32BIT kernels of course often are... Fix this by dropping the .set <ISA> directives entirely now that Kconfig should be ensuring that kernels including this code are built with a suitable -march= compiler flag. Signed-off-by: Paul Burton <[email protected]> Cc: Markos Chandras <[email protected]> Cc: James Hogan <[email protected]> Cc: <[email protected]> # 3.16+ Cc: [email protected] Cc: [email protected] Patchwork: https://patchwork.linux-mips.org/patch/10869/ Signed-off-by: Ralf Baechle <[email protected]>
2015-12-22MIPS: uaccess: Take EVA into account in [__]clear_userJames Hogan1-0/+2
__clear_user() (and clear_user() which uses it), always access the user mode address space, which results in EVA store instructions when EVA is enabled even if the current user address limit is KERNEL_DS. Fix this by adding a new symbol __bzero_kernel for the normal kernel address space bzero in EVA mode, and call that from __clear_user() if eva_kernel_access(). Signed-off-by: James Hogan <[email protected]> Cc: Markos Chandras <[email protected]> Cc: Paul Burton <[email protected]> Cc: Leonid Yegoshin <[email protected]> Cc: [email protected] Patchwork: https://patchwork.linux-mips.org/patch/10844/ Signed-off-by: Ralf Baechle <[email protected]>
2015-12-04module: use a structure to encapsulate layout.Rusty Russell1-3/+3
Makes it easier to handle init vs core cleanly, though the change is fairly invasive across random architectures. It simplifies the rbtree code immediately, however, while keeping the core data together in the same cachline (now iff the rbtree code is enabled). Acked-by: Peter Zijlstra <[email protected]> Reviewed-by: Josh Poimboeuf <[email protected]> Signed-off-by: Rusty Russell <[email protected]> Signed-off-by: Jiri Kosina <[email protected]>
2015-11-15Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linusLinus Torvalds22-173/+618
Pull MIPS updates from Ralf Baechle: "These are the highlists of the main MIPS pull request for 4.4: - Add latencytop support - Support appended DTBs - VDSO support and initially use it for gettimeofday. - Drop the .MIPS.abiflags and ELF NOTE sections from vmlinux - Support for the 5KE, an internal test core. - Switch all MIPS platfroms to libata drivers. - Improved support, cleanups for ralink and Lantiq platforms. - Support for the new xilfpga platform. - A number of DTB improvments for BMIPS. - Improved support for CM and CPS. - Minor JZ4740 and BCM47xx enhancements" * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (120 commits) MIPS: idle: add case for CPU_5KE MIPS: Octeon: Support APPENDED_DTB MIPS: vmlinux: create a section for appended DTB MIPS: Clean up compat_siginfo_t MIPS: Fix PAGE_MASK definition MIPS: BMIPS: Enable GZIP ramdisk and timed printks MIPS: Add xilfpga defconfig MIPS: xilfpga: Add mipsfpga platform code MIPS: xilfpga: Add xilfpga device tree files. dt-bindings: MIPS: Document xilfpga bindings and boot style MIPS: Make MIPS_CMDLINE_DTB default MIPS: Make the kernel arguments from dtb available MIPS: Use USE_OF as the guard for appended dtb MIPS: BCM63XX: Use pr_* instead of printk MIPS: Loongson: Cleanup CONFIG_LOONGSON_SUSPEND. MIPS: lantiq: Disable xbar fpi burst mode MIPS: lantiq: Force the crossbar to big endian MIPS: lantiq: Initialize the USB core on boot MIPS: lantiq: Return correct value for fpi clock on ar9 MIPS: ralink: Add missing clock on rt305x ...
2015-11-12Merge branch '4.3-fixes' into mips-for-linux-nextRalf Baechle3-3/+14
2015-11-12MIPS: idle: add case for CPU_5KEAurelien Jarno1-0/+1
While the 5KE processors have never been taped out, they exists though a CP0.PRId and experimental RTLs or QEMU implementations. Add a case entry in the idle code, as they can use the standard idle loop like the 5K processors. Signed-off-by: Aurelien Jarno <[email protected]> Cc: [email protected] Patchwork: https://patchwork.linux-mips.org/patch/11099/ Signed-off-by: Ralf Baechle <[email protected]>
2015-11-12MIPS: vmlinux: create a section for appended DTBAaro Koskinen2-0/+9
For bootloaders that support booting only ELF kernels and load only ELF segments to memory there is no easy way to supply DTB without kernel recompilation. For that purpose, create a section called .appended_dtb that can be later updated with board-specific DTB using binutils e.g. at kernel installation time. Signed-off-by: Aaro Koskinen <[email protected]> Cc: [email protected] Patchwork: https://patchwork.linux-mips.org/patch/11114/ Signed-off-by: Ralf Baechle <[email protected]>
2015-11-11MIPS: Make the kernel arguments from dtb availableJonas Gorski1-7/+17
Similar to how arm allows using selecting between bootloader arguments, dtb arguments and both, allow to select them on mips. But since we have less control over the place of the dtb do not modify it but instead use the boot_command_line for merging them. The default is "use bootloader arguments" to keep the current behaviour as default. Signed-off-by: Jonas Gorski <[email protected]> Cc: [email protected] Cc: Kevin Cernekee <[email protected]> Cc: Florian Fainelli <[email protected]> Cc: Zubair Lutfullah Kakakhel <[email protected]> Cc: James Hogan <[email protected]> Cc: John Crispin <[email protected]> Cc: Ganesan Ramalingam <[email protected]> Cc: Jayachandran C <[email protected]> Cc: Andrew Bresticker <[email protected]> Cc: James Hartley <[email protected]> Patchwork: https://patchwork.linux-mips.org/patch/11284/ Signed-off-by: Ralf Baechle <[email protected]>
2015-11-11MIPS: Add LATENCYTOP supportAaro Koskinen1-12/+15
Add LATENCYTOP support for MIPS. Tested on OCTEON. Signed-off-by: Aaro Koskinen <[email protected]> Cc: [email protected] Patchwork: https://patchwork.linux-mips.org/patch/11353/ Signed-off-by: Ralf Baechle <[email protected]>
2015-11-11MIPS: VDSO: Add implementations of gettimeofday() and clock_gettime()Alex Smith2-6/+109
Add user-mode implementations of gettimeofday() and clock_gettime() to the VDSO. This is currently usable with 2 clocksources: the CP0 count register, which is accessible to user-mode via RDHWR on R2 and later cores, or the MIPS Global Interrupt Controller (GIC) timer, which provides a "user-mode visible" section containing a mirror of its counter registers. This section must be mapped into user memory, which is done below the VDSO data page. When a supported clocksource is not in use, the VDSO functions will return -ENOSYS, which causes libc to fall back on the standard syscall path. When support for neither of these clocksources is compiled into the kernel at all, the VDSO still provides clock_gettime(), as the coarse realtime/monotonic clocks can still be implemented. However, gettimeofday() is not provided in this case as nothing can be done without a suitable clocksource. This causes the symbol lookup to fail in libc and it will then always use the standard syscall path. This patch includes a workaround for a bug in QEMU which results in RDHWR on the CP0 count register always returning a constant (incorrect) value. A fix for this has been submitted, and the workaround can be removed after the fix has been in stable releases for a reasonable amount of time. A simple performance test which calls gettimeofday() 1000 times in a loop and calculates the average execution time gives the following results on a Malta + I6400 (running at 20MHz): - Syscall: ~31000 ns - VDSO (GIC): ~15000 ns - VDSO (CP0): ~9500 ns [[email protected]: - Minor code re-arrangements in order for mappings to be made in the order they appear to the process' address space. - Move do_{monotonic, realtime} outside of the MIPS_CLOCK_VSYSCALL ifdef - Use gic_get_usm_range so we can do the GIC mapping in the arch/mips/kernel/vdso instead of the GIC irqchip driver] Signed-off-by: Alex Smith <[email protected]> Signed-off-by: Markos Chandras <[email protected]> Cc: [email protected] Cc: [email protected] Patchwork: https://patchwork.linux-mips.org/patch/11338/ Signed-off-by: Ralf Baechle <[email protected]>
2015-11-11MIPS: Initial implementation of a VDSOAlex Smith4-98/+86
Add an initial implementation of a proper (i.e. an ELF shared library) VDSO. With this commit it does not export any symbols, it only replaces the current signal return trampoline page. A later commit will add user implementations of gettimeofday()/clock_gettime(). To support both new toolchains and old ones which don't generate ABI flags section, we define its content manually and then use a tool (genvdso) to patch up the section to have the correct name and type. genvdso also extracts symbol offsets ({,rt_}sigreturn) needed by the kernel, and generates a C file containing a "struct mips_vdso_image" containing both the VDSO data and these offsets. This C file is compiled into the kernel. On 64-bit kernels we require a different VDSO for each supported ABI, so we may build up to 3 different VDSOs. The VDSO to use is selected by the mips_abi structure. A kernel/user shared data page is created and mapped below the VDSO image. This is currently empty, but will be used by the user time function implementations which are added later. [[email protected]: - Add more comments - Move abi detection in genvdso.h since it's the get_symbol function that needs it. - Add an R6 specific way to calculate the base address of VDSO in order to avoid the branch instruction which affects performance. - Do not patch .gnu.attributes since it's not needed for dynamic linking. - Simplify Makefile a little bit. - checkpatch fixes - Restrict VDSO support for binutils < 2.25 for pre-R6 - Include atomic64.h for O32 variant on MIPS64] Signed-off-by: Alex Smith <[email protected]> Signed-off-by: Markos Chandras <[email protected]> Cc: Matthew Fortune <[email protected]> Cc: [email protected] Patchwork: https://patchwork.linux-mips.org/patch/11337/ Signed-off-by: Ralf Baechle <[email protected]>
2015-11-11MIPS: Extend hardware table walking support to MIPS64Paul Burton1-2/+1
Extend the existing support for Hardware Table Walking (HTW) to MIPS64 systems by supporting PMDs & setting the pointer size bit in PWSize, then ceasing to blacklist HTW on MIPS64 systems. Signed-off-by: Paul Burton <[email protected]> Cc: [email protected] Cc: Steven J. Hill <[email protected]> Cc: Joshua Kinard <[email protected]> Cc: Leonid Yegoshin <[email protected]> Cc: Maciej W. Rozycki <[email protected]> Cc: Paul Gortmaker <[email protected]> Cc: [email protected] Cc: James Hogan <[email protected]> Cc: Markos Chandras <[email protected]> Patchwork: https://patchwork.linux-mips.org/patch/11224/ Signed-off-by: Ralf Baechle <[email protected]>