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* irqchip: armada-370-xp: fix IPI race conditionLior Amsalem2014-02-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit a6f089e95b1e08cdea9633d50ad20aa5d44ba64d upstream. In the Armada 370/XP driver, when we receive an IRQ 0, we read the list of doorbells that caused the interrupt from register ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS. This gives the list of IPIs that were generated. However, instead of acknowledging only the IPIs that were generated, we acknowledge *all* the IPIs, by writing ~IPI_DOORBELL_MASK in the ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS register. This creates a race condition: if a new IPI that isn't part of the ones read into the temporary "ipimask" variable is fired before we acknowledge all IPIs, then we will simply loose it. This is causing scheduling hangs on SMP intensive workloads. It is important to mention that this ARMADA_370_XP_IN_DRBEL_CAUSE_OFFS register has the following behavior: "A CPU write of 0 clears the bits in this field. A CPU write of 1 has no effect". This is what allows us to simply write ~ipimask to acknoledge the handled IPIs. Notice that the same problem is present in the MSI implementation, but it will be fixed as a separate patch, so that this IPI fix can be pushed to older stable versions as appropriate (all the way to 3.8), while the MSI code only appeared in 3.13. Signed-off-by: Lior Amsalem <alior@marvell.com> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Fixes: 344e873e5657e8dc0 'arm: mvebu: Add IPI support via doorbells' Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Jason Cooper <jason@lakedaemon.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge tag 'cleanup-for-linus-2' of ↵Linus Torvalds2013-05-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc Pull ARM SoC late cleanups from Arnd Bergmann: "These are cleanups and smaller changes that either depend on earlier feature branches or came in late during the development cycle. We normally try to get all cleanups early, so these are the exceptions: - A follow-up on the clocksource reworks, hopefully the last time we need to merge clocksource subsystem changes through arm-soc. A first set of patches was part of the original 3.10 arm-soc cleanup series because of interdependencies with timer drivers now moved out of arch/arm. - Migrating the SPEAr13xx platform away from using auxdata for DMA channel descriptions towards using information in device tree, based on the earlier SPEAr multiplatform series - A few follow-ups on the Atmel SAMA5 support and other changes for Atmel at91 based on the larger at91 reworks. - Moving the armada irqchip implementation to drivers/irqchip - Several OMAP cleanups following up on the larger series already merged in 3.10." * tag 'cleanup-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (50 commits) ARM: OMAP4: change the device names in usb_bind_phy ARM: OMAP2+: Fix mismerge for timer.c between ff931c82 and da4a686a ARM: SPEAr: conditionalize SMP code ARM: arch_timer: Silence debug preempt warnings ARM: OMAP: remove unused variable serial: amba-pl011: fix !CONFIG_DMA_ENGINE case ata: arasan: remove the need for platform_data ARM: at91/sama5d34ek.dts: remove not needed compatibility string ARM: at91: dts: add MCI DMA support ARM: at91: dts: add i2c dma support ARM: at91: dts: set #dma-cells to the correct value ARM: at91: suspend both memory controllers on at91sam9263 irqchip: armada-370-xp: slightly cleanup irq controller driver irqchip: armada-370-xp: move IRQ handler to avoid forward declaration irqchip: move IRQ driver for Armada 370/XP ARM: mvebu: move L2 cache initialization in init_early() devtree: add binding documentation for sp804 ARM: integrator-cp: convert use CLKSRC_OF for timer init ARM: versatile: use OF init for sp804 timer ARM: versatile: add versatile dtbs to dtbs target ...
* irqchip: armada-370-xp: slightly cleanup irq controller driverThomas Petazzoni2013-04-15
| | | | | | | | | | | | In preparation for the introduction of MSI support in the IRQ controller driver, we clarify the implementation of IPI using additional defines for the manipulation of doorbells. Just like IPIs are implemented using doorbells, MSIs will also use doorbells, so it makes sense to do this preparatory cleanup first. Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Tested-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com> Signed-off-by: Jason Cooper <jason@lakedaemon.net>
* irqchip: armada-370-xp: move IRQ handler to avoid forward declarationThomas Petazzoni2013-04-15
| | | | | | | | | | | | If we move the IRQ handler function above the initialization function, we avoid a forward declaration. This wasn't done as part of the previous commit, in order to increase the readibility of the previous commit, who was also moving the IRQ controller driver from arch/arm to drivers/irqchip. Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Tested-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com> Signed-off-by: Jason Cooper <jason@lakedaemon.net>
* irqchip: move IRQ driver for Armada 370/XPThomas Petazzoni2013-04-15
When the Marvell Armada 370/XP support was included in the kernel, the drivers/irqchip/ directory didn't exist and the minimal infrastructure in it also didn't exist. Now that we have those things in place, we move the Armada 370/XP IRQ controller driver from arch/arm/mach-mvebu/irq-armada-370-xp.c to drivers/irqchip/irq-armada-370-xp.c. Note in order to reduce code movement and therefore ease the review of this patch, we intentionally introduce a forward declaration of armada_370_xp_handle_irq(). It is in fact not needed because this handler can now simply be implemented before armada_370_xp_mpic_of_init(). That will be done in the next commit. Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Tested-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com> Signed-off-by: Jason Cooper <jason@lakedaemon.net>