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2017-10-06powerpc/powernv: Make opal_event_shutdown() callable from IRQ contextMichael Ellerman1-1/+7
In opal_event_shutdown() we free all the IRQs hanging off the opal_event_irqchip. However it's not safe to do so if we're called from IRQ context, because free_irq() wants to synchronise versus IRQ context. This can lead to warnings and a stuck system. For example from sysrq-b: Trying to free IRQ 17 from IRQ context! ------------[ cut here ]------------ WARNING: CPU: 0 PID: 0 at kernel/irq/manage.c:1461 __free_irq+0x398/0x8d0 ... NIP __free_irq+0x398/0x8d0 LR __free_irq+0x394/0x8d0 Call Trace: __free_irq+0x394/0x8d0 (unreliable) free_irq+0xa4/0x140 opal_event_shutdown+0x128/0x180 opal_shutdown+0x1c/0xb0 pnv_shutdown+0x20/0x40 machine_restart+0x38/0x90 emergency_restart+0x28/0x40 sysrq_handle_reboot+0x24/0x40 __handle_sysrq+0x198/0x590 hvc_poll+0x48c/0x8c0 hvc_handle_interrupt+0x1c/0x50 __handle_irq_event_percpu+0xe8/0x6e0 handle_irq_event_percpu+0x34/0xe0 handle_irq_event+0xc4/0x210 handle_level_irq+0x250/0x770 generic_handle_irq+0x5c/0xa0 opal_handle_events+0x11c/0x240 opal_interrupt+0x38/0x50 __handle_irq_event_percpu+0xe8/0x6e0 handle_irq_event_percpu+0x34/0xe0 handle_irq_event+0xc4/0x210 handle_fasteoi_irq+0x174/0xa10 generic_handle_irq+0x5c/0xa0 __do_irq+0xbc/0x4e0 call_do_irq+0x14/0x24 do_IRQ+0x18c/0x540 hardware_interrupt_common+0x158/0x180 We can avoid that by using disable_irq_nosync() rather than free_irq(). Although it doesn't fully free the IRQ, it should be sufficient when we're shutting down, particularly in an emergency. Add an in_interrupt() check and use free_irq() when we're shutting down normally. It's probably OK to use disable_irq_nosync() in that case too, but for now it's safer to leave that behaviour as-is. Fixes: 9f0fd0499d30 ("powerpc/powernv: Add a virtual irqchip for opal events") Reported-by: Anton Blanchard <anton@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2017-02-09powerpc/opal-irqchip: Use interrupt names if presentBenjamin Herrenschmidt1-13/+42
Recent versions of OPAL can provide names for the various OPAL interrupts, so let's use them. This also modernises the code that fetches the interrupt array to use the helpers provided by the generic code instead of hand-parsing the property. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [mpe: Free irqs on error, check allocation of names, consolidate error handling, whitespace.] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-20powerpc: Remove all usages of NO_IRQMichael Ellerman1-2/+2
NO_IRQ has been == 0 on powerpc for just over ten years (since commit 0ebfff1491ef ("[POWERPC] Add new interrupt mapping core and change platforms to use it")). It's also 0 on most other arches. Although it's fairly harmless, every now and then it causes confusion when a driver is built on powerpc and another arch which doesn't define NO_IRQ. There's at least 6 definitions of NO_IRQ in drivers/, at least some of which are to work around that problem. So we'd like to remove it. This is fairly trivial in the arch code, we just convert: if (irq == NO_IRQ) to if (!irq) if (irq != NO_IRQ) to if (irq) irq = NO_IRQ; to irq = 0; return NO_IRQ; to return 0; And a few other odd cases as well. At least for now we keep the #define NO_IRQ, because there is driver code that uses NO_IRQ and the fixes to remove those will go via other trees. Note we also change some occurrences in PPC sound drivers, drivers/ps3, and drivers/macintosh. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-08-09powerpc/xics: Properly set Edge/Level type and enable resendBenjamin Herrenschmidt1-1/+2
This sets the type of the interrupt appropriately. We set it as follow: - If not mapped from the device-tree, we use edge. This is the case of the virtual interrupts and PCI MSIs for example. - If mapped from the device-tree and #interrupt-cells is 2 (PAPR compliant), we use the second cell to set the appropriate type - If mapped from the device-tree and #interrupt-cells is 1 (current OPAL on P8 does that), we assume level sensitive since those are typically going to be the PSI LSIs which are level sensitive. Additionally, we mark the interrupts requested via the opal_interrupts property all level. This is a bit fishy but the best we can do until we fix OPAL to properly expose them with a complete descriptor. It is also correct for the current HW anyway as OPAL interrupts are currently PCI error and PSI interrupts which are level. Finally now that edge interrupts are properly identified, we can enable CONFIG_HARDIRQS_SW_RESEND which will make the core re-send them if they occur while masked, which some drivers rely upon. This fixes issues with lost interrupts on some Mellanox adapters. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-18powerpc/opal-irqchip: Fix deadlock introduced by "Fix double endian conversion"Alistair Popple1-1/+13
Commit 25642e1459ac ("powerpc/opal-irqchip: Fix double endian conversion") fixed an endian bug by calling opal_handle_events() in opal_event_unmask(). However this introduced a deadlock if we find an event is active during unmasking and call opal_handle_events() again. The bad call sequence is: opal_interrupt() -> opal_handle_events() -> generic_handle_irq() -> handle_level_irq() -> raw_spin_lock(&desc->lock) handle_irq_event(desc) unmask_irq(desc) -> opal_event_unmask() -> opal_handle_events() -> generic_handle_irq() -> handle_level_irq() -> raw_spin_lock(&desc->lock) (BOOM) When generating multiple opal events in quick succession this would lead to the following stall warnings: EEH: Fenced PHB#0 detected, location: U78C9.001.WZS09XA-P1-C32 INFO: rcu_sched detected stalls on CPUs/tasks: 12-...: (1 GPs behind) idle=68f/140000000000001/0 softirq=860/861 fqs=2065 15-...: (1 GPs behind) idle=be5/140000000000001/0 softirq=1142/1143 fqs=2065 (detected by 13, t=2102 jiffies, g=1325, c=1324, q=602) NMI watchdog: BUG: soft lockup - CPU#18 stuck for 22s! [irqbalance:2696] INFO: rcu_sched detected stalls on CPUs/tasks: 12-...: (1 GPs behind) idle=68f/140000000000001/0 softirq=860/861 fqs=8371 15-...: (1 GPs behind) idle=be5/140000000000001/0 softirq=1142/1143 fqs=8371 (detected by 20, t=8407 jiffies, g=1325, c=1324, q=1290) This patch corrects the problem by queuing the work if an event is active during unmasking, which is similar to the pre-endian fix behaviour. Fixes: 25642e1459ac ("powerpc/opal-irqchip: Fix double endian conversion") Signed-off-by: Alistair Popple <alistair@popple.id.au> Reported-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-12-08powerpc/opal-irqchip: Fix double endian conversionAlistair Popple1-29/+29
The OPAL event calls return a mask of events that are active in big endian format. This is checked when unmasking the events in the irqchip by comparison with a cached value. The cached value was stored in big endian format but should've been converted to CPU endian first. This bug leads to OPAL event delivery being delayed or dropped on some systems. Symptoms may include a non-functional console. The bug is fixed by calling opal_handle_events(...) instead of duplicating code in opal_event_unmask(...). Fixes: 9f0fd0499d30 ("powerpc/powernv: Add a virtual irqchip for opal events") Cc: stable@vger.kernel.org # v4.2+ Reported-by: Douglas L Lehr <dllehr@us.ibm.com> Signed-off-by: Alistair Popple <alistair@popple.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-10-13irqdomain: Use irq_domain_get_of_node() instead of direct field accessMarc Zyngier1-1/+1
The struct irq_domain contains a "struct device_node *" field (of_node) that is almost the only link between the irqdomain and the device tree infrastructure. In order to prepare for the removal of that field, convert all users to use irq_domain_get_of_node() instead. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-and-tested-by: Hanjun Guo <hanjun.guo@linaro.org> Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: <linux-arm-kernel@lists.infradead.org> Cc: Tomasz Nowicki <tomasz.nowicki@linaro.org> Cc: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com> Cc: Graeme Gregory <graeme@xora.org.uk> Cc: Jake Oshins <jakeo@microsoft.com> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Jason Cooper <jason@lakedaemon.net> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Link: http://lkml.kernel.org/r/1444737105-31573-2-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-07-30genirq/irqdomain: Allow irq domain aliasingMarc Zyngier1-1/+2
It is not uncommon (at least with the ARM stuff) to have a piece of hardware that implements different flavours of "interrupts". A typical example of this is the GICv3 ITS, which implements standard PCI/MSI support, but also some form of "generic MSI". So far, the PCI/MSI domain is registered using the ITS device_node, so that irq_find_host can return it. On the contrary, the raw MSI domain is not registered with an device_node, making it impossible to be looked up by another subsystem (obviously, using the same device_node twice would only result in confusion, as it is not defined which one irq_find_host would return). A solution to this is to "type" domains that may be aliasing, and to be able to lookup an device_node that matches a given type. For this, we introduce irq_find_matching_host() as a superset of irq_find_host: struct irq_domain *irq_find_matching_host(struct device_node *node, enum irq_domain_bus_token bus_token); where bus_token is the "type" we want to match the domain against (so far, only DOMAIN_BUS_ANY is defined). This result in some moderately invasive changes on the PPC side (which is the only user of the .match method). This has otherwise no functionnal change. Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Cc: <linux-arm-kernel@lists.infradead.org> Cc: Yijing Wang <wangyijing@huawei.com> Cc: Ma Jun <majun258@huawei.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Duc Dang <dhdang@apm.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Jason Cooper <jason@lakedaemon.net> Link: http://lkml.kernel.org/r/1438091186-10244-2-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-06-18powerpc/powernv: Increase opal-irqchip initcall priorityAlistair Popple1-0/+4
The eeh subsystem for powernv requires the opal event irqchip to be initialised prior to initialisation or the following errors are produced (and eeh doesn't work as expected): irq: XICS didn't like hwirq-0x9 to VIRQ17 mapping (rc=-22) pnv_eeh_post_init: Can't request OPAL event interrupt (0) On powernv eeh is initialised from a subsys_initcall due to a check for machine_is(powernv) in eeh_init(). This patch increases the initcall priority of opal_event_init() to an arch_initcall to ensure the opal event interface is initialised prior to any users of it. Signed-off-by: Alistair Popple <alistair@popple.id.au> Reported-by: Daniel Axtens <dja@axtens.net> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-05-22opal: Remove events notifierAlistair Popple1-10/+6
All users of the old opal events notifier have been converted over to the irq domain so remove the event notifier functions. Signed-off-by: Alistair Popple <alistair@popple.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-05-22powerpc/powernv: Add a virtual irqchip for opal eventsAlistair Popple1-0/+253
Whenever an interrupt is received for opal the linux kernel gets a bitfield indicating certain events that have occurred and need handling by the various device drivers. Currently this is handled using a notifier interface where we call every device driver that has registered to receive opal events. This approach has several drawbacks. For example each driver has to do its own checking to see if the event is relevant as well as event masking. There is also no easy method of recording the number of times we receive particular events. This patch solves these issues by exposing opal events via the standard interrupt APIs by adding a new interrupt chip and domain. Drivers can then register for the appropriate events using standard kernel calls such as irq_of_parse_and_map(). Signed-off-by: Alistair Popple <alistair@popple.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>