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* treewide: Make remaining source files non-executableJoe Perches2016-12-135-0/+0
| | | | | | | | | | | | .c and .h source files should not be executable, change the permissions to 0644. [ This would normally go through Andrew Morton, but his ancient patch-based toolchain doesn't do permission changes ] Signed-off-by: Joe Perches <joe@perches.com> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'irq-core-for-linus' of ↵Linus Torvalds2016-12-1325-572/+518
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq updates from Thomas Gleixner: "The irq department provides: - a major update to the auto affinity management code, which is used by multi-queue devices - move of the microblaze irq chip driver into the common driver code so it can be shared between microblaze, powerpc and MIPS - a series of updates to the ARM GICV3 interrupt controller - the usual pile of fixes and small improvements all over the place" * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (25 commits) powerpc/virtex: Use generic xilinx irqchip driver irqchip/xilinx: Try to fall back if xlnx,kind-of-intr not provided irqchip/xilinx: Add support for parent intc irqchip/xilinx: Rename get_irq to xintc_get_irq irqchip/xilinx: Restructure and use jump label api irqchip/xilinx: Clean up print messages microblaze/irqchip: Move intc driver to irqchip ARM: virt: Select ARM_GIC_V3_ITS ARM: gic-v3-its: Add 32bit support to GICv3 ITS irqchip/gic-v3-its: Specialise readq and writeq accesses irqchip/gic-v3-its: Specialise flush_dcache operation irqchip/gic-v3-its: Narrow down Entry Size when used as a divider irqchip/gic-v3-its: Change unsigned types for AArch32 compatibility irqchip/gic-v3: Use nops macro for Cavium ThunderX erratum 23154 irqchip/gic-v3: Convert arm64 GIC accessors to {read,write}_sysreg_s genirq/msi: Drop artificial PCI dependency irqchip/bcm7038-l1: Implement irq_cpu_offline() callback genirq/affinity: Use default affinity mask for reserved vectors genirq/affinity: Take reserved vectors into account when spreading irqs PCI: Remove the irq_affinity mask from struct pci_dev ...
| * Merge tag 'irqchip-4.10' of ↵Thomas Gleixner2016-11-2919-489/+376
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core Pull irqchip updates for 4.10 from Marc Zyngier: - xylinx interrupt controller made architecture agnostic (microblaze, ppc, mips) - GICv3 ITS now supported on 32bit ARM (mostly useful for virtual machines) - Some arm64 GICv3 cleanups
| | * powerpc/virtex: Use generic xilinx irqchip driverZubair Lutfullah Kakakhel2016-11-297-213/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Xilinx interrupt controller driver is now available in drivers/irqchip. Switch to using that driver. Acked-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
| | * irqchip/xilinx: Try to fall back if xlnx,kind-of-intr not providedZubair Lutfullah Kakakhel2016-11-291-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The powerpc dts file does not have the xlnx,kind-of-intr property. Instead of erroring out, give a warning instead. And attempt to continue to probe the interrupt controller while assuming kind-of-intr is 0x0 as a fall back. Acked-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
| | * irqchip/xilinx: Add support for parent intcZubair Lutfullah Kakakhel2016-11-291-2/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The MIPS based xilfpga platform has the following IRQ structure Peripherals --> xilinx_intcontroller -> mips_cpu_int controller Add support for the driver to chain the irq handler Signed-off-by: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
| | * irqchip/xilinx: Rename get_irq to xintc_get_irqZubair Lutfullah Kakakhel2016-11-293-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that the driver is generic and used by multiple archs, get_irq is too generic. Rename get_irq to xintc_get_irq to avoid any conflicts Acked-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
| | * irqchip/xilinx: Restructure and use jump label apiZubair Lutfullah Kakakhel2016-11-291-52/+66
| | | | | | | | | | | | | | | | | | | | | | | | | | | Add a global structure to house various variables. And cleanup read/write handling by using jump label api. Tested-by; Michal Simek <michal.simek@xilinx.com> Signed-off-by: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
| | * irqchip/xilinx: Clean up print messagesZubair Lutfullah Kakakhel2016-11-291-9/+9
| | | | | | | | | | | | | | | | | | | | | | | | Remove __func__ and prefix irq-xilinx in various debug prints Acked-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
| | * microblaze/irqchip: Move intc driver to irqchipZubair Lutfullah Kakakhel2016-11-295-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Xilinx AXI Interrupt Controller IP block is used by the MIPS based xilfpga platform and a few PowerPC based platforms. Move the interrupt controller code out of arch/microblaze so that it can be used by everyone Tested-by: Michal Simek <michal.simek@xilinx.com> Signed-off-by: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
| | * ARM: virt: Select ARM_GIC_V3_ITSVladimir Murzin2016-11-291-0/+1
| | | | | | | | | | | | | | | | | | | | | This patch allows ARM guests to use GICv3 ITS on an arm64 host Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
| | * ARM: gic-v3-its: Add 32bit support to GICv3 ITSVladimir Murzin2016-11-291-7/+47
| | | | | | | | | | | | | | | | | | | | | | | | Wire-up flush_dcache, readq- and writeq-like gic-v3-its assessors, so GICv3 ITS gets all it needs to be built and run. Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
| | * irqchip/gic-v3-its: Specialise readq and writeq accessesVladimir Murzin2016-11-292-12/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | readq and writeq type of assessors are not supported in AArch32, so we need to specialise them and glue later with series of 32-bit accesses on AArch32 side. Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
| | * irqchip/gic-v3-its: Specialise flush_dcache operationVladimir Murzin2016-11-292-9/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | It'd be better to switch to CMA... but before that done redirect flush_dcache operation, so 32-bit implementation could be wired latter. Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
| | * irqchip/gic-v3-its: Narrow down Entry Size when used as a dividerVladimir Murzin2016-11-291-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | GITS_BASER<n>'s Entry Size is much smaller than 64-bit, but when it used as a divider it forces compiler to generate __aeabi_uldivmod if build in 32-bit mode. So, casting it to int (like it is done in other places) where used as a divider would give a hint to compiler that 32-bit division can be used. Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
| | * irqchip/gic-v3-its: Change unsigned types for AArch32 compatibilityVladimir Murzin2016-11-292-16/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | Make sure that constants which are supposed to be applied on 64-bit data is actually unsigned long long, so they won't be truncated when used in 32-bit mode. Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
| | * irqchip/gic-v3: Use nops macro for Cavium ThunderX erratum 23154Will Deacon2016-11-291-7/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The workaround for Cavium ThunderX erratum 23154 has a homebrew pipeflush built out of NOP sequences around the read of the IAR. This patch converts the code to use the new nops macro, which makes it a little easier to read. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
| | * irqchip/gic-v3: Convert arm64 GIC accessors to {read,write}_sysreg_sWill Deacon2016-11-291-28/+17
| |/ | | | | | | | | | | | | | | | | | | | | | | The GIC system registers are accessed using open-coded wrappers around the mrs_s/msr_s asm macros. This patch moves the code over to the {read,wrote}_sysreg_s accessors instead, reducing the amount of explicit asm blocks in the arch headers. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
| * genirq/msi: Drop artificial PCI dependencyMarc Zyngier2016-11-221-3/+1
| | | | | | | | | | | | | | | | | | | | | | The generic MSI layer doesn't have any PCI ties anymore, and the build hack should have been removed some time ago. Fixes: d9109698be6e ("genirq: Introduce msi_domain_alloc/free_irqs()") Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Link: http://lkml.kernel.org/r/1479806476-20801-1-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * irqchip/bcm7038-l1: Implement irq_cpu_offline() callbackFlorian Fainelli2016-11-181-0/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We did not implement an irq_cpu_offline callback for our irqchip, yet we support setting a given IRQ's affinity. This resulted in interrupts whose affinity mask included CPUs being taken offline not to work correctly once the CPU had been put offline. Fixes: 5f7f0317ed28 ("IRQCHIP: Add new driver for BCM7038-style level 1 interrupt controllers") Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Cc: linux-mips@linux-mips.org Cc: jason@lakedaemon.net Cc: marc.zyngier@arm.com Cc: cernekee@gmail.com Cc: jaedon.shin@gmail.com Cc: ralf@linux-mips.org Cc: justinpopo6@gmail.com Link: http://lkml.kernel.org/r/1477948656-12966-2-git-send-email-f.fainelli@gmail.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * genirq/affinity: Use default affinity mask for reserved vectorsThomas Gleixner2016-11-161-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The reserved vectors at the beginning and the end of the vector space get cpu_possible_mask assigned as their affinity mask. All other non-auto affine interrupts get the default irq affinity mask assigned. Using cpu_possible_mask breaks that rule. Treat them like any other interrupt and use irq_default_affinity as target mask. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Christoph Hellwig <hch@lst.de>
| * genirq/affinity: Take reserved vectors into account when spreading irqsChristoph Hellwig2016-11-161-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The recent addition of reserved vectors at the beginning or the end of the vector space did not take the reserved vectors at the beginning into account for the various loop exit conditions. As a consequence the last vectors of the spread area are not included into the spread algorithm and are treated like the reserved vectors at the end of the vector space and get the default affinity mask assigned. Sum up the affinity vectors and the reserved vectors at the beginning and use the sum as exit condition. [ tglx: Fixed all conditions instead of only one and massaged changelog ] Signed-off-by: Christoph Hellwig <hch@lst.de> Link: http://lkml.kernel.org/r/1479201178-29604-2-git-send-email-hch@lst.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * PCI: Remove the irq_affinity mask from struct pci_devChristoph Hellwig2016-11-091-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This has never been used, and now is totally unreferenced. Nuke it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Jens Axboe <axboe@kernel.dk> Cc: linux-block@vger.kernel.org Cc: linux-pci@vger.kernel.org Link: http://lkml.kernel.org/r/1478654107-7384-7-git-send-email-hch@lst.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * PCI/MSI: Provide pci_alloc_irq_vectors_affinity()Christoph Hellwig2016-11-092-12/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a variant of pci_alloc_irq_vectors() that allows passing a struct irq_affinity to provide fine-grained IRQ affinity control. For now this means being able to exclude vectors at the beginning or end of the MSI vector space, but it could also be used for any other quirks needed in the future (e.g. more vectors than CPUs, or excluding CPUs from the spreading). Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Jens Axboe <axboe@kernel.dk> Cc: linux-block@vger.kernel.org Cc: linux-pci@vger.kernel.org Link: http://lkml.kernel.org/r/1478654107-7384-6-git-send-email-hch@lst.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * PCI/MSI: Propagate IRQ affinity description through the MSI codeChristoph Hellwig2016-11-091-33/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | No API change yet, just pass it down all the way from pci_alloc_irq_vectors() to the core MSI code. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Jens Axboe <axboe@kernel.dk> Cc: linux-block@vger.kernel.org Cc: linux-pci@vger.kernel.org Link: http://lkml.kernel.org/r/1478654107-7384-5-git-send-email-hch@lst.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * genirq/affinity: Handle pre/post vectors in irq_create_affinity_masks()Christoph Hellwig2016-11-093-25/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Only calculate the affinity for the main I/O vectors, and skip the pre or post vectors specified by struct irq_affinity. Also remove the irq_affinity cpumask argument that has never been used. If we ever need it in the future we can pass it through struct irq_affinity. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Jens Axboe <axboe@kernel.dk> Cc: linux-block@vger.kernel.org Cc: linux-pci@vger.kernel.org Link: http://lkml.kernel.org/r/1478654107-7384-4-git-send-email-hch@lst.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * genirq/affinity: Handle pre/post vectors in irq_calc_affinity_vectors()Christoph Hellwig2016-11-093-20/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Only calculate the affinity for the main I/O vectors, and skip the pre or post vectors specified by struct irq_affinity. Also remove the irq_affinity cpumask argument that has never been used. If we ever need it in the future we can pass it through struct irq_affinity. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Acked-by: Jens Axboe <axboe@kernel.dk> Cc: linux-block@vger.kernel.org Cc: linux-pci@vger.kernel.org Link: http://lkml.kernel.org/r/1478654107-7384-3-git-send-email-hch@lst.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * genirq/affinity: Introduce struct irq_affinityChristoph Hellwig2016-11-091-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some drivers (various network and RDMA adapter for example) have a MSI-X vector layout where most of the vectors are used for I/O queues and should have CPU affinity assigned to them, but some (usually 1 but sometimes more) at the beginning or end are used for low-performance admin or configuration work and should not have any explicit affinity assigned to them. Add a new irq_affinity structure, which will be passed through a variant of pci_irq_alloc_vectors that allows to specify these requirements (and is extensible to any future quirks in that area) so that the core IRQ affinity algorithm can take this quirks into account. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Acked-by: Jens Axboe <axboe@kernel.dk> Cc: linux-block@vger.kernel.org Cc: linux-pci@vger.kernel.org Link: http://lkml.kernel.org/r/1478654107-7384-2-git-send-email-hch@lst.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | Merge branch 'timers-core-for-linus' of ↵Linus Torvalds2016-12-1361-1041/+1479
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer updates from Thomas Gleixner: "The time/timekeeping/timer folks deliver with this update: - Fix a reintroduced signed/unsigned issue and cleanup the whole signed/unsigned mess in the timekeeping core so this wont happen accidentaly again. - Add a new trace clock based on boot time - Prevent injection of random sleep times when PM tracing abuses the RTC for storage - Make posix timers configurable for real tiny systems - Add tracepoints for the alarm timer subsystem so timer based suspend wakeups can be instrumented - The usual pile of fixes and updates to core and drivers" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits) timekeeping: Use mul_u64_u32_shr() instead of open coding it timekeeping: Get rid of pointless typecasts timekeeping: Make the conversion call chain consistently unsigned timekeeping_Force_unsigned_clocksource_to_nanoseconds_conversion alarmtimer: Add tracepoints for alarm timers trace: Update documentation for mono, mono_raw and boot clock trace: Add an option for boot clock as trace clock timekeeping: Add a fast and NMI safe boot clock timekeeping/clocksource_cyc2ns: Document intended range limitation timekeeping: Ignore the bogus sleep time if pm_trace is enabled selftests/timers: Fix spelling mistake "Asyncrhonous" -> "Asynchronous" clocksource/drivers/bcm2835_timer: Unmap region obtained by of_iomap clocksource/drivers/arm_arch_timer: Map frame with of_io_request_and_map() arm64: dts: rockchip: Arch counter doesn't tick in system suspend clocksource/drivers/arm_arch_timer: Don't assume clock runs in suspend posix-timers: Make them configurable posix_cpu_timers: Move the add_device_randomness() call to a proper place timer: Move sys_alarm from timer.c to itimer.c ptp_clock: Allow for it to be optional Kconfig: Regenerate *.c_shipped files after previous changes ...
| * | timekeeping: Use mul_u64_u32_shr() instead of open coding itThomas Gleixner2016-12-091-21/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The resume code must deal with a clocksource delta which is potentially big enough to overflow the 64bit mult. Replace the open coded handling with the proper function. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Parit Bhargava <prarit@redhat.com> Cc: Laurent Vivier <lvivier@redhat.com> Cc: "Christopher S. Hall" <christopher.s.hall@intel.com> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Liav Rehana <liavr@mellanox.com> Cc: John Stultz <john.stultz@linaro.org> Link: http://lkml.kernel.org/r/20161208204228.921674404@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | timekeeping: Get rid of pointless typecastsThomas Gleixner2016-12-091-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cycle_t is defined as u64, so casting it to u64 is a pointless and confusing exercise. cycle_t should simply go away and be replaced with a plain u64 to avoid further confusion. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Parit Bhargava <prarit@redhat.com> Cc: Laurent Vivier <lvivier@redhat.com> Cc: "Christopher S. Hall" <christopher.s.hall@intel.com> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Liav Rehana <liavr@mellanox.com> Cc: John Stultz <john.stultz@linaro.org> Link: http://lkml.kernel.org/r/20161208204228.844699737@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | timekeeping: Make the conversion call chain consistently unsignedThomas Gleixner2016-12-091-13/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Propagating a unsigned value through signed variables and functions makes absolutely no sense and is just prone to (re)introduce subtle signed vs. unsigned issues as happened recently. Clean it up. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Parit Bhargava <prarit@redhat.com> Cc: Laurent Vivier <lvivier@redhat.com> Cc: "Christopher S. Hall" <christopher.s.hall@intel.com> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Liav Rehana <liavr@mellanox.com> Cc: John Stultz <john.stultz@linaro.org> Link: http://lkml.kernel.org/r/20161208204228.765843099@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | timekeeping_Force_unsigned_clocksource_to_nanoseconds_conversionThomas Gleixner2016-12-091-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The clocksource delta to nanoseconds conversion is using signed math, but the delta is unsigned. This makes the conversion space smaller than necessary and in case of a multiplication overflow the conversion can become negative. The conversion is done with scaled math: s64 nsec_delta = ((s64)clkdelta * clk->mult) >> clk->shift; Shifting a signed integer right obvioulsy preserves the sign, which has interesting consequences: - Time jumps backwards - __iter_div_u64_rem() which is used in one of the calling code pathes will take forever to piecewise calculate the seconds/nanoseconds part. This has been reported by several people with different scenarios: David observed that when stopping a VM with a debugger: "It was essentially the stopped by debugger case. I forget exactly why, but the guest was being explicitly stopped from outside, it wasn't just scheduling lag. I think it was something in the vicinity of 10 minutes stopped." When lifting the stop the machine went dead. The stopped by debugger case is not really interesting, but nevertheless it would be a good thing not to die completely. But this was also observed on a live system by Liav: "When the OS is too overloaded, delta will get a high enough value for the msb of the sum delta * tkr->mult + tkr->xtime_nsec to be set, and so after the shift the nsec variable will gain a value similar to 0xffffffffff000000." Unfortunately this has been reintroduced recently with commit 6bd58f09e1d8 ("time: Add cycles to nanoseconds translation"). It had been fixed a year ago already in commit 35a4933a8959 ("time: Avoid signed overflow in timekeeping_get_ns()"). Though it's not surprising that the issue has been reintroduced because the function itself and the whole call chain uses s64 for the result and the propagation of it. The change in this recent commit is subtle: s64 nsec; - nsec = (d * m + n) >> s: + nsec = d * m + n; + nsec >>= s; d being type of cycle_t adds another level of obfuscation. This wouldn't have happened if the previous change to unsigned computation would have made the 'nsec' variable u64 right away and a follow up patch had cleaned up the whole call chain. There have been patches submitted which basically did a revert of the above patch leaving everything else unchanged as signed. Back to square one. This spawned a admittedly pointless discussion about potential users which rely on the unsigned behaviour until someone pointed out that it had been fixed before. The changelogs of said patches added further confusion as they made finally false claims about the consequences for eventual users which expect signed results. Despite delta being cycle_t, aka. u64, it's very well possible to hand in a signed negative value and the signed computation will happily return the correct result. But nobody actually sat down and analyzed the code which was added as user after the propably unintended signed conversion. Though in sensitive code like this it's better to analyze it proper and make sure that nothing relies on this than hunting the subtle wreckage half a year later. After analyzing all call chains it stands that no caller can hand in a negative value (which actually would work due to the s64 cast) and rely on the signed math to do the right thing. Change the conversion function to unsigned math. The conversion of all call chains is done in a follow up patch. This solves the starvation issue, which was caused by the negative result, but it does not solve the underlying problem. It merily procrastinates it. When the timekeeper update is deferred long enough that the unsigned multiplication overflows, then time going backwards is observable again. It does neither solve the issue of clocksources with a small counter width which will wrap around possibly several times and cause random time stamps to be generated. But those are usually not found on systems used for virtualization, so this is likely a non issue. I took the liberty to claim authorship for this simply because analyzing all callsites and writing the changelog took substantially more time than just making the simple s/s64/u64/ change and ignore the rest. Fixes: 6bd58f09e1d8 ("time: Add cycles to nanoseconds translation") Reported-by: David Gibson <david@gibson.dropbear.id.au> Reported-by: Liav Rehana <liavr@mellanox.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Parit Bhargava <prarit@redhat.com> Cc: Laurent Vivier <lvivier@redhat.com> Cc: "Christopher S. Hall" <christopher.s.hall@intel.com> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: John Stultz <john.stultz@linaro.org> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20161208204228.688545601@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | alarmtimer: Add tracepoints for alarm timersBaolin Wang2016-12-013-10/+144
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Alarm timers are one of the mechanisms to wake up a system from suspend, but there exist no tracepoints to analyse which process/thread armed an alarmtimer. Add tracepoints for start/cancel/expire of individual alarm timers and one for tracing the suspend time decision when to resume the system. The following trace excerpt illustrates the new mechanism: Binder:3292_2-3304 [000] d..2 149.981123: alarmtimer_cancel: alarmtimer:ffffffc1319a7800 type:REALTIME expires:1325463120000000000 now:1325376810370370245 Binder:3292_2-3304 [000] d..2 149.981136: alarmtimer_start: alarmtimer:ffffffc1319a7800 type:REALTIME expires:1325376840000000000 now:1325376810370384591 Binder:3292_9-3953 [000] d..2 150.212991: alarmtimer_cancel: alarmtimer:ffffffc1319a5a00 type:BOOTTIME expires:179552000000 now:150154008122 Binder:3292_9-3953 [000] d..2 150.213006: alarmtimer_start: alarmtimer:ffffffc1319a5a00 type:BOOTTIME expires:179551000000 now:150154025622 system_server-3000 [002] ...1 162.701940: alarmtimer_suspend: alarmtimer type:REALTIME expires:1325376840000000000 The wakeup time which is selected at suspend time allows to map it back to the task arming the timer: Binder:3292_2. [ tglx: Store alarm timer expiry time instead of some useless RTC relative information, add proper type information for wakeups which are handled via the clock_nanosleep/freezer and massage the changelog. ] Signed-off-by: Baolin Wang <baolin.wang@linaro.org> Signed-off-by: John Stultz <john.stultz@linaro.org> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Link: http://lkml.kernel.org/r/1480372524-15181-5-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | trace: Update documentation for mono, mono_raw and boot clockJoel Fernandes2016-11-291-0/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Documentation was missing for mono and mono_raw, add them and also for the boot clock introduced in this series. Signed-off-by: Joel Fernandes <joelaf@google.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Link: http://lkml.kernel.org/r/1480372524-15181-8-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | trace: Add an option for boot clock as trace clockJoel Fernandes2016-11-291-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Unlike monotonic clock, boot clock as a trace clock will account for time spent in suspend useful for tracing suspend/resume. This uses earlier introduced infrastructure for using the fast boot clock. Signed-off-by: Joel Fernandes <joelaf@google.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Link: http://lkml.kernel.org/r/1480372524-15181-7-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | timekeeping: Add a fast and NMI safe boot clockJoel Fernandes2016-11-292-0/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This boot clock can be used as a tracing clock and will account for suspend time. To keep it NMI safe since we're accessing from tracing, we're not using a separate timekeeper with updates to monotonic clock and boot offset protected with seqlocks. This has the following minor side effects: (1) Its possible that a timestamp be taken after the boot offset is updated but before the timekeeper is updated. If this happens, the new boot offset is added to the old timekeeping making the clock appear to update slightly earlier: CPU 0 CPU 1 timekeeping_inject_sleeptime64() __timekeeping_inject_sleeptime(tk, delta); timestamp(); timekeeping_update(tk, TK_CLEAR_NTP...); (2) On 32-bit systems, the 64-bit boot offset (tk->offs_boot) may be partially updated. Since the tk->offs_boot update is a rare event, this should be a rare occurrence which postprocessing should be able to handle. Signed-off-by: Joel Fernandes <joelaf@google.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/1480372524-15181-6-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | timekeeping/clocksource_cyc2ns: Document intended range limitationChris Metcalf2016-11-291-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The "cycles" argument should not be an absolute clocksource cycle value, as the implementation's arithmetic will overflow relatively easily with wide (64 bit) clocksource counters. For performance, the implementation is simple and fast, since the function is intended for only relatively small delta values of clocksource cycles. [jstultz: Fixed up to merge against HEAD & commit message tweaks, also included rewording suggestion by Ingo] Signed-off-by: Chris Metcalf <cmetcalf@mellanox.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Link: http://lkml.kernel.org/r/1480372524-15181-4-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | timekeeping: Ignore the bogus sleep time if pm_trace is enabledChen Yu2016-11-295-1/+52
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Power management suspend/resume tracing (ab)uses the RTC to store suspend/resume information persistently. As a consequence the RTC value is clobbered when timekeeping is resumed and tries to inject the sleep time. Commit a4f8f6667f09 ("timekeeping: Cap array access in timekeeping_debug") plugged a out of bounds array access in the timekeeping debug code which was caused by the clobbered RTC value, but we still use the clobbered RTC value for sleep time injection into kernel timekeeping, which will result in random adjustments depending on the stored "hash" value. To prevent this keep track of the RTC clobbering and ignore the invalid RTC timestamp at resume. If the system resumed successfully clear the flag, which marks the RTC as unusable, warn the user about the RTC clobber and recommend to adjust the RTC with 'ntpdate' or 'rdate'. [jstultz: Fixed up pr_warn formating, and implemented suggestions from Ingo] [ tglx: Rewrote changelog ] Originally-from: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Chen Yu <yu.c.chen@intel.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Acked-by: Pavel Machek <pavel@ucw.cz> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Prarit Bhargava <prarit@redhat.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Xunlei Pang <xlpang@redhat.com> Cc: Len Brown <lenb@kernel.org> Link: http://lkml.kernel.org/r/1480372524-15181-3-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | selftests/timers: Fix spelling mistake "Asyncrhonous" -> "Asynchronous"Colin Ian King2016-11-291-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Trivial fix to spelling mistake Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Shuah Khan <shuah@kernel.org> Link: http://lkml.kernel.org/r/1480372524-15181-2-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | clocksource/drivers/bcm2835_timer: Unmap region obtained by of_iomapArvind Yadav2016-11-221-4/+10
| | | | | | | | | | | | | | | | | | | | | | | | Free memory mapping, if bcm2835_timer_init is not successful. Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
| * | clocksource/drivers/arm_arch_timer: Map frame with of_io_request_and_map()Stephen Boyd2016-11-211-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | Let's use the of_io_request_and_map() API so that the frame region is protected and shows up in /proc/iomem. Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com>
| * | arm64: dts: rockchip: Arch counter doesn't tick in system suspendBrian Norris2016-11-211-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The "arm,no-tick-in-suspend" property was introduced to note implementations where the system counter does not quite follow the ARM specification that it "must be implemented in an always-on power domain". Particularly, RK3399's counter stops ticking when we switch from the 24MHz clock to the 32KHz clock in low-power suspend, so let's mark it as such. Signed-off-by: Brian Norris <briannorris@chromium.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
| * | clocksource/drivers/arm_arch_timer: Don't assume clock runs in suspendBrian Norris2016-11-212-1/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ARM specifies that the system counter "must be implemented in an always-on power domain," and so we try to use the counter as a source of timekeeping across suspend/resume. Unfortunately, some SoCs (e.g., Rockchip's RK3399) do not keep the counter ticking properly when switched from their high-power clock to the lower-power clock used in system suspend. Support this quirk by adding a new device tree property. Signed-off-by: Brian Norris <briannorris@chromium.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
| * | posix-timers: Make them configurableNicolas Pitre2016-11-1615-13/+200
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some embedded systems have no use for them. This removes about 25KB from the kernel binary size when configured out. Corresponding syscalls are routed to a stub logging the attempt to use those syscalls which should be enough of a clue if they were disabled without proper consideration. They are: timer_create, timer_gettime: timer_getoverrun, timer_settime, timer_delete, clock_adjtime, setitimer, getitimer, alarm. The clock_settime, clock_gettime, clock_getres and clock_nanosleep syscalls are replaced by simple wrappers compatible with CLOCK_REALTIME, CLOCK_MONOTONIC and CLOCK_BOOTTIME only which should cover the vast majority of use cases with very little code. Signed-off-by: Nicolas Pitre <nico@linaro.org> Acked-by: Richard Cochran <richardcochran@gmail.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: John Stultz <john.stultz@linaro.org> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Cc: Paul Bolle <pebolle@tiscali.nl> Cc: linux-kbuild@vger.kernel.org Cc: netdev@vger.kernel.org Cc: Michal Marek <mmarek@suse.com> Cc: Edward Cree <ecree@solarflare.com> Link: http://lkml.kernel.org/r/1478841010-28605-7-git-send-email-nicolas.pitre@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | posix_cpu_timers: Move the add_device_randomness() call to a proper placeNicolas Pitre2016-11-162-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is no logical relation between add_device_randomness() and posix_cpu_timers_exit(). Let's move the former to where the later is called. This way, when posix-cpu-timers.c is compiled out, there is no need to worry about not losing a call to add_device_randomness(). Signed-off-by: Nicolas Pitre <nico@linaro.org> Acked-by: John Stultz <john.stultz@linaro.org> Cc: Paul Bolle <pebolle@tiscali.nl> Cc: linux-kbuild@vger.kernel.org Cc: netdev@vger.kernel.org Cc: Richard Cochran <richardcochran@gmail.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Michal Marek <mmarek@suse.com> Cc: Edward Cree <ecree@solarflare.com> Link: http://lkml.kernel.org/r/1478841010-28605-6-git-send-email-nicolas.pitre@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | timer: Move sys_alarm from timer.c to itimer.cNicolas Pitre2016-11-163-16/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move the only user of alarm_setitimer to itimer.c where it is defined. This allows for making alarm_setitimer static, and dropping it from the build when __ARCH_WANT_SYS_ALARM is not defined. Signed-off-by: Nicolas Pitre <nico@linaro.org> Acked-by: John Stultz <john.stultz@linaro.org> Cc: Paul Bolle <pebolle@tiscali.nl> Cc: linux-kbuild@vger.kernel.org Cc: netdev@vger.kernel.org Cc: Richard Cochran <richardcochran@gmail.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Michal Marek <mmarek@suse.com> Cc: Edward Cree <ecree@solarflare.com> Link: http://lkml.kernel.org/r/1478841010-28605-5-git-send-email-nicolas.pitre@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | ptp_clock: Allow for it to be optionalNicolas Pitre2016-11-1618-50/+69
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to break the hard dependency between the PTP clock subsystem and ethernet drivers capable of being clock providers, this patch provides simple PTP stub functions to allow linkage of those drivers into the kernel even when the PTP subsystem is configured out. Drivers must be ready to accept NULL from ptp_clock_register() in that case. And to make it possible for PTP to be configured out, the select statement in those driver's Kconfig menu entries is converted to the new "imply" statement. This way the PTP subsystem may have Kconfig dependencies of its own, such as POSIX_TIMERS, without having to make those ethernet drivers unavailable if POSIX timers are cconfigured out. And when support for POSIX timers is selected again then the default config option for PTP clock support will automatically be adjusted accordingly. The pch_gbe driver is a bit special as it relies on extra code in drivers/ptp/ptp_pch.c. Therefore we let the make process descend into drivers/ptp/ even if PTP_1588_CLOCK is unselected. Signed-off-by: Nicolas Pitre <nico@linaro.org> Acked-by: Richard Cochran <richardcochran@gmail.com> Acked-by: Edward Cree <ecree@solarflare.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: John Stultz <john.stultz@linaro.org> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Cc: Paul Bolle <pebolle@tiscali.nl> Cc: linux-kbuild@vger.kernel.org Cc: netdev@vger.kernel.org Cc: Michal Marek <mmarek@suse.com> Link: http://lkml.kernel.org/r/1478841010-28605-4-git-send-email-nicolas.pitre@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | Kconfig: Regenerate *.c_shipped files after previous changesNicolas Pitre2016-11-162-858/+753
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Nicolas Pitre <nico@linaro.org> Cc: Paul Bolle <pebolle@tiscali.nl> Cc: linux-kbuild@vger.kernel.org Cc: netdev@vger.kernel.org Cc: Richard Cochran <richardcochran@gmail.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Michal Marek <mmarek@suse.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Edward Cree <ecree@solarflare.com> Link: http://lkml.kernel.org/r/1478841010-28605-3-git-send-email-nicolas.pitre@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
| * | Kconfig: Introduce the "imply" keywordNicolas Pitre2016-11-166-19/+108
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The "imply" keyword is a weak version of "select" where the target config symbol can still be turned off, avoiding those pitfalls that come with the "select" keyword. This is useful e.g. with multiple drivers that want to indicate their ability to hook into a secondary subsystem while allowing the user to configure that subsystem out without also having to unset these drivers. Currently, the same effect can almost be achieved with: config DRIVER_A tristate config DRIVER_B tristate config DRIVER_C tristate config DRIVER_D tristate [...] config SUBSYSTEM_X tristate default DRIVER_A || DRIVER_B || DRIVER_C || DRIVER_D || [...] This is unwieldy to maintain especially with a large number of drivers. Furthermore, there is no easy way to restrict the choice for SUBSYSTEM_X to y or n, excluding m, when some drivers are built-in. The "select" keyword allows for excluding m, but it excludes n as well. Hence this "imply" keyword. The above becomes: config DRIVER_A tristate imply SUBSYSTEM_X config DRIVER_B tristate imply SUBSYSTEM_X [...] config SUBSYSTEM_X tristate This is much cleaner, and way more flexible than "select". SUBSYSTEM_X can still be configured out, and it can be set as a module when none of the drivers are configured in or all of them are modular. Signed-off-by: Nicolas Pitre <nico@linaro.org> Acked-by: Richard Cochran <richardcochran@gmail.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: John Stultz <john.stultz@linaro.org> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Cc: Paul Bolle <pebolle@tiscali.nl> Cc: linux-kbuild@vger.kernel.org Cc: netdev@vger.kernel.org Cc: Michal Marek <mmarek@suse.com> Cc: Edward Cree <ecree@solarflare.com> Link: http://lkml.kernel.org/r/1478841010-28605-2-git-send-email-nicolas.pitre@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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