From 02cea3958664723a5d2236f0f0058de97c7e4693 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 5 Feb 2015 14:06:23 +0100 Subject: genirq: Provide disable_hardirq() For things like netpoll there is a need to disable an interrupt from atomic context. Currently netpoll uses disable_irq() which will sleep-wait on threaded handlers and thus forced_irqthreads breaks things. Provide disable_hardirq(), which uses synchronize_hardirq() to only wait for active hardirq handlers; also change synchronize_hardirq() to return the status of threaded handlers. This will allow one to try-disable an interrupt from atomic context, or in case of request_threaded_irq() to only wait for the hardirq part. Suggested-by: Sabrina Dubroca Signed-off-by: Peter Zijlstra (Intel) Cc: Arnd Bergmann Cc: David Miller Cc: Eyal Perry Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Quentin Lambert Cc: Randy Dunlap Cc: Russell King Link: http://lkml.kernel.org/r/20150205130623.GH5029@twins.programming.kicks-ass.net [ Fixed typos and such. ] Signed-off-by: Ingo Molnar --- include/linux/interrupt.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/interrupt.h') diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index d9b05b5bf8c7..3bb01b9a379c 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -184,6 +184,7 @@ extern void devm_free_irq(struct device *dev, unsigned int irq, void *dev_id); #endif extern void disable_irq_nosync(unsigned int irq); +extern bool disable_hardirq(unsigned int irq); extern void disable_irq(unsigned int irq); extern void disable_percpu_irq(unsigned int irq); extern void enable_irq(unsigned int irq); -- cgit v1.3-14-g43fede From 737eb0301f296d55c22350c6968ff1ef51bacb5f Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Fri, 20 Feb 2015 14:53:46 +0000 Subject: genirq / PM: better describe IRQF_NO_SUSPEND semantics The IRQF_NO_SUSPEND flag is intended to be used for interrupts required to be enabled during the suspend-resume cycle. This mostly consists of IPIs and timer interrupts, potentially including chained irqchip interrupts if these are necessary to handle timers or IPIs. If an interrupt does not fall into one of the aforementioned categories, requesting it with IRQF_NO_SUSPEND is likely incorrect. Using IRQF_NO_SUSPEND does not guarantee that the interrupt can wake the system from a suspended state. For an interrupt to be able to trigger a wakeup, it may be necessary to program various components of the system. In these cases it is necessary to use {enable,disabled}_irq_wake. Unfortunately, several drivers assume that IRQF_NO_SUSPEND ensures that an IRQ can wake up the system, and the documentation can be read ambiguously w.r.t. this property. This patch updates the documentation regarding IRQF_NO_SUSPEND to make this caveat explicit, hopefully making future misuse rarer. Cleanup of existing misuse will occur as part of later patch series. Signed-off-by: Mark Rutland Acked-by: Peter Zijlstra (Intel) Signed-off-by: Rafael J. Wysocki --- Documentation/power/suspend-and-interrupts.txt | 6 ++++-- include/linux/interrupt.h | 4 +++- 2 files changed, 7 insertions(+), 3 deletions(-) (limited to 'include/linux/interrupt.h') diff --git a/Documentation/power/suspend-and-interrupts.txt b/Documentation/power/suspend-and-interrupts.txt index 2f9c5a5fcb25..50493c9284b4 100644 --- a/Documentation/power/suspend-and-interrupts.txt +++ b/Documentation/power/suspend-and-interrupts.txt @@ -40,8 +40,10 @@ but also to IPIs and to some other special-purpose interrupts. The IRQF_NO_SUSPEND flag is used to indicate that to the IRQ subsystem when requesting a special-purpose interrupt. It causes suspend_device_irqs() to -leave the corresponding IRQ enabled so as to allow the interrupt to work all -the time as expected. +leave the corresponding IRQ enabled so as to allow the interrupt to work as +expected during the suspend-resume cycle, but does not guarantee that the +interrupt will wake the system from a suspended state -- for such cases it is +necessary to use enable_irq_wake(). Note that the IRQF_NO_SUSPEND flag affects the entire IRQ and not just one user of it. Thus, if the IRQ is shared, all of the interrupt handlers installed diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index d9b05b5bf8c7..606771c7cac2 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -52,7 +52,9 @@ * IRQF_ONESHOT - Interrupt is not reenabled after the hardirq handler finished. * Used by threaded interrupts which need to keep the * irq line disabled until the threaded handler has been run. - * IRQF_NO_SUSPEND - Do not disable this IRQ during suspend + * IRQF_NO_SUSPEND - Do not disable this IRQ during suspend. Does not guarantee + * that this interrupt will wake the system from a suspended + * state. See Documentation/power/suspend-and-interrupts.txt * IRQF_FORCE_RESUME - Force enable it on resume even if IRQF_NO_SUSPEND is set * IRQF_NO_THREAD - Interrupt cannot be threaded * IRQF_EARLY_RESUME - Resume IRQ early during syscore instead of at device -- cgit v1.3-14-g43fede From 17f480342026e54000731acaa69bf32787ce46cb Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 27 Feb 2015 00:07:55 +0100 Subject: genirq / PM: Add flag for shared NO_SUSPEND interrupt lines It currently is required that all users of NO_SUSPEND interrupt lines pass the IRQF_NO_SUSPEND flag when requesting the IRQ or the WARN_ON_ONCE() in irq_pm_install_action() will trigger. That is done to warn about situations in which unprepared interrupt handlers may be run unnecessarily for suspended devices and may attempt to access those devices by mistake. However, it may cause drivers that have no technical reasons for using IRQF_NO_SUSPEND to set that flag just because they happen to share the interrupt line with something like a timer. Moreover, the generic handling of wakeup interrupts introduced by commit 9ce7a25849e8 (genirq: Simplify wakeup mechanism) only works for IRQs without any NO_SUSPEND users, so the drivers of wakeup devices needing to use shared NO_SUSPEND interrupt lines for signaling system wakeup generally have to detect wakeup in their interrupt handlers. Thus if they happen to share an interrupt line with a NO_SUSPEND user, they also need to request that their interrupt handlers be run after suspend_device_irqs(). In both cases the reason for using IRQF_NO_SUSPEND is not because the driver in question has a genuine need to run its interrupt handler after suspend_device_irqs(), but because it happens to share the line with some other NO_SUSPEND user. Otherwise, the driver would do without IRQF_NO_SUSPEND just fine. To make it possible to specify that condition explicitly, introduce a new IRQ action handler flag for shared IRQs, IRQF_COND_SUSPEND, that, when set, will indicate to the IRQ core that the interrupt user is generally fine with suspending the IRQ, but it also can tolerate handler invocations after suspend_device_irqs() and, in particular, it is capable of detecting system wakeup and triggering it as appropriate from its interrupt handler. That will allow us to work around a problem with a shared timer interrupt line on at91 platforms. Link: http://marc.info/?l=linux-kernel&m=142252777602084&w=2 Link: http://marc.info/?t=142252775300011&r=1&w=2 Link: https://lkml.org/lkml/2014/12/15/552 Reported-by: Boris Brezillon Signed-off-by: Rafael J. Wysocki Acked-by: Peter Zijlstra (Intel) Acked-by: Mark Rutland --- include/linux/interrupt.h | 5 +++++ include/linux/irqdesc.h | 1 + kernel/irq/manage.c | 7 ++++++- kernel/irq/pm.c | 7 ++++++- 4 files changed, 18 insertions(+), 2 deletions(-) (limited to 'include/linux/interrupt.h') diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index 606771c7cac2..2e88580194f0 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -59,6 +59,10 @@ * IRQF_NO_THREAD - Interrupt cannot be threaded * IRQF_EARLY_RESUME - Resume IRQ early during syscore instead of at device * resume time. + * IRQF_COND_SUSPEND - If the IRQ is shared with a NO_SUSPEND user, execute this + * interrupt handler after suspending interrupts. For system + * wakeup devices users need to implement wakeup detection in + * their interrupt handlers. */ #define IRQF_DISABLED 0x00000020 #define IRQF_SHARED 0x00000080 @@ -72,6 +76,7 @@ #define IRQF_FORCE_RESUME 0x00008000 #define IRQF_NO_THREAD 0x00010000 #define IRQF_EARLY_RESUME 0x00020000 +#define IRQF_COND_SUSPEND 0x00040000 #define IRQF_TIMER (__IRQF_TIMER | IRQF_NO_SUSPEND | IRQF_NO_THREAD) diff --git a/include/linux/irqdesc.h b/include/linux/irqdesc.h index faf433af425e..dd1109fb241e 100644 --- a/include/linux/irqdesc.h +++ b/include/linux/irqdesc.h @@ -78,6 +78,7 @@ struct irq_desc { #ifdef CONFIG_PM_SLEEP unsigned int nr_actions; unsigned int no_suspend_depth; + unsigned int cond_suspend_depth; unsigned int force_resume_depth; #endif #ifdef CONFIG_PROC_FS diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 196a06fbc122..886d09e691d5 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -1474,8 +1474,13 @@ int request_threaded_irq(unsigned int irq, irq_handler_t handler, * otherwise we'll have trouble later trying to figure out * which interrupt is which (messes up the interrupt freeing * logic etc). + * + * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and + * it cannot be set along with IRQF_NO_SUSPEND. */ - if ((irqflags & IRQF_SHARED) && !dev_id) + if (((irqflags & IRQF_SHARED) && !dev_id) || + (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) || + ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND))) return -EINVAL; desc = irq_to_desc(irq); diff --git a/kernel/irq/pm.c b/kernel/irq/pm.c index 3ca532592704..5204a6d1b985 100644 --- a/kernel/irq/pm.c +++ b/kernel/irq/pm.c @@ -43,9 +43,12 @@ void irq_pm_install_action(struct irq_desc *desc, struct irqaction *action) if (action->flags & IRQF_NO_SUSPEND) desc->no_suspend_depth++; + else if (action->flags & IRQF_COND_SUSPEND) + desc->cond_suspend_depth++; WARN_ON_ONCE(desc->no_suspend_depth && - desc->no_suspend_depth != desc->nr_actions); + (desc->no_suspend_depth + + desc->cond_suspend_depth) != desc->nr_actions); } /* @@ -61,6 +64,8 @@ void irq_pm_remove_action(struct irq_desc *desc, struct irqaction *action) if (action->flags & IRQF_NO_SUSPEND) desc->no_suspend_depth--; + else if (action->flags & IRQF_COND_SUSPEND) + desc->cond_suspend_depth--; } static bool suspend_device_irq(struct irq_desc *desc, int irq) -- cgit v1.3-14-g43fede From d8bf368d0631d4bc2612d8bf2e4e8e74e620d0cc Mon Sep 17 00:00:00 2001 From: Valentin Rothberg Date: Thu, 5 Mar 2015 15:23:08 +0100 Subject: genirq: Remove the deprecated 'IRQF_DISABLED' request_irq() flag entirely The IRQF_DISABLED flag is a NOOP and has been scheduled for removal since Linux v2.6.36 by commit 6932bf37bed4 ("genirq: Remove IRQF_DISABLED from core code"). According to commit e58aa3d2d0cc ("genirq: Run irq handlers with interrupts disabled"), running IRQ handlers with interrupts enabled can cause stack overflows when the interrupt line of the issuing device is still active. This patch ends the grace period for IRQF_DISABLED (i.e., SA_INTERRUPT in older versions of Linux) and removes the definition and all remaining usages of this flag. There's still a few non-functional references left in the kernel source: - The bigger hunk in Documentation/scsi/ncr53c8xx.txt is removed entirely as IRQF_DISABLED is gone now; the usage in older kernel versions (including the old SA_INTERRUPT flag) should be discouraged. The trouble of using IRQF_SHARED is a general problem and not specific to any driver. - I left the reference in Documentation/PCI/MSI-HOWTO.txt untouched since it has already been removed in linux-next. - All remaining references are changelogs that I suggest to keep. Signed-off-by: Valentin Rothberg Cc: Afzal Mohammed Cc: Arnd Bergmann Cc: Brian Norris Cc: Christoph Hellwig Cc: Dan Carpenter Cc: David Woodhouse Cc: Ewan Milne Cc: Eyal Perry Cc: Felipe Balbi Cc: Greg Kroah-Hartman Cc: H. Peter Anvin Cc: Hannes Reinecke Cc: Hongliang Tao Cc: Huacai Chen Cc: Jiri Kosina Cc: Jonathan Corbet Cc: Keerthy Cc: Laurent Pinchart Cc: Linus Torvalds Cc: Nishanth Menon Cc: Paul Bolle Cc: Peter Ujfalusi Cc: Peter Zijlstra Cc: Quentin Lambert Cc: Rajendra Nayak Cc: Ralf Baechle Cc: Santosh Shilimkar Cc: Sricharan R Cc: Thomas Gleixner Cc: Tony Lindgren Cc: Zhou Wang Cc: iss_storagedev@hp.com Cc: linux-mips@linux-mips.org Cc: linux-mtd@lists.infradead.org Link: http://lkml.kernel.org/r/1425565425-12604-1-git-send-email-valentinrothberg@gmail.com Signed-off-by: Ingo Molnar --- Documentation/scsi/ncr53c8xx.txt | 25 ------------------------- Documentation/scsi/tmscsim.txt | 4 ---- arch/mips/loongson/loongson-3/hpet.c | 2 +- drivers/block/cpqarray.c | 4 ++-- drivers/bus/omap_l3_noc.c | 4 ++-- drivers/bus/omap_l3_smx.c | 10 ++++------ drivers/mtd/nand/hisi504_nand.c | 3 +-- drivers/usb/isp1760/isp1760-core.c | 3 +-- drivers/usb/isp1760/isp1760-udc.c | 4 ++-- include/linux/interrupt.h | 3 --- 10 files changed, 13 insertions(+), 49 deletions(-) (limited to 'include/linux/interrupt.h') diff --git a/Documentation/scsi/ncr53c8xx.txt b/Documentation/scsi/ncr53c8xx.txt index 1d508dcbf859..8586efff1e99 100644 --- a/Documentation/scsi/ncr53c8xx.txt +++ b/Documentation/scsi/ncr53c8xx.txt @@ -786,7 +786,6 @@ port address 0x1400. irqm:1 same as initial settings (assumed BIOS settings) irqm:2 always totem pole irqm:0x10 driver will not use IRQF_SHARED flag when requesting irq - irqm:0x20 driver will not use IRQF_DISABLED flag when requesting irq (Bits 0x10 and 0x20 can be combined with hardware irq mode option) @@ -1231,30 +1230,6 @@ they only refer to system buffers that are well aligned. So, a work around may only be needed under Linux when a scatter/gather list is not used and when the SCSI DATA IN phase is reentered after a phase mismatch. -14.5 IRQ sharing problems - -When an IRQ is shared by devices that are handled by different drivers, it -may happen that one driver complains about the request of the IRQ having -failed. Inder Linux-2.0, this may be due to one driver having requested the -IRQ using the IRQF_DISABLED flag but some other having requested the same IRQ -without this flag. Under both Linux-2.0 and linux-2.2, this may be caused by -one driver not having requested the IRQ with the IRQF_SHARED flag. - -By default, the ncr53c8xx and sym53c8xx drivers request IRQs with both the -IRQF_DISABLED and the IRQF_SHARED flag under Linux-2.0 and with only the IRQF_SHARED -flag under Linux-2.2. - -Under Linux-2.0, you can disable use of IRQF_DISABLED flag from the boot -command line by using the following option: - - ncr53c8xx=irqm:0x20 (for the generic ncr53c8xx driver) - sym53c8xx=irqm:0x20 (for the sym53c8xx driver) - -If this does not fix the problem, then you may want to check how all other -drivers are requesting the IRQ and report the problem. Note that if at least -a single driver does not request the IRQ with the IRQF_SHARED flag (share IRQ), -then the request of the IRQ obviously will not succeed for all the drivers. - 15. SCSI problem troubleshooting 15.1 Problem tracking diff --git a/Documentation/scsi/tmscsim.txt b/Documentation/scsi/tmscsim.txt index 0810132772a8..0e0322bf0020 100644 --- a/Documentation/scsi/tmscsim.txt +++ b/Documentation/scsi/tmscsim.txt @@ -107,10 +107,6 @@ produced errors and started to corrupt my disks. So don't do that! A 37.50 MHz PCI bus works for me, though, but I don't recommend using higher clocks than the 33.33 MHz being in the PCI spec. -If you want to share the IRQ with another device and the driver refuses to -do so, you might succeed with changing the DC390_IRQ type in tmscsim.c to -IRQF_SHARED | IRQF_DISABLED. - 3.Features ---------- diff --git a/arch/mips/loongson/loongson-3/hpet.c b/arch/mips/loongson/loongson-3/hpet.c index e898d68668a9..5c21cd3bd339 100644 --- a/arch/mips/loongson/loongson-3/hpet.c +++ b/arch/mips/loongson/loongson-3/hpet.c @@ -162,7 +162,7 @@ static irqreturn_t hpet_irq_handler(int irq, void *data) static struct irqaction hpet_irq = { .handler = hpet_irq_handler, - .flags = IRQF_DISABLED | IRQF_NOBALANCING | IRQF_TIMER, + .flags = IRQF_NOBALANCING | IRQF_TIMER, .name = "hpet", }; diff --git a/drivers/block/cpqarray.c b/drivers/block/cpqarray.c index 2b9440384536..f749df9e15cd 100644 --- a/drivers/block/cpqarray.c +++ b/drivers/block/cpqarray.c @@ -405,8 +405,8 @@ static int cpqarray_register_ctlr(int i, struct pci_dev *pdev) goto Enomem4; } hba[i]->access.set_intr_mask(hba[i], 0); - if (request_irq(hba[i]->intr, do_ida_intr, - IRQF_DISABLED|IRQF_SHARED, hba[i]->devname, hba[i])) + if (request_irq(hba[i]->intr, do_ida_intr, IRQF_SHARED, + hba[i]->devname, hba[i])) { printk(KERN_ERR "cpqarray: Unable to get irq %d for %s\n", hba[i]->intr, hba[i]->devname); diff --git a/drivers/bus/omap_l3_noc.c b/drivers/bus/omap_l3_noc.c index 029bc73de001..11f7982cbdb3 100644 --- a/drivers/bus/omap_l3_noc.c +++ b/drivers/bus/omap_l3_noc.c @@ -284,7 +284,7 @@ static int omap_l3_probe(struct platform_device *pdev) */ l3->debug_irq = platform_get_irq(pdev, 0); ret = devm_request_irq(l3->dev, l3->debug_irq, l3_interrupt_handler, - IRQF_DISABLED, "l3-dbg-irq", l3); + 0x0, "l3-dbg-irq", l3); if (ret) { dev_err(l3->dev, "request_irq failed for %d\n", l3->debug_irq); @@ -293,7 +293,7 @@ static int omap_l3_probe(struct platform_device *pdev) l3->app_irq = platform_get_irq(pdev, 1); ret = devm_request_irq(l3->dev, l3->app_irq, l3_interrupt_handler, - IRQF_DISABLED, "l3-app-irq", l3); + 0x0, "l3-app-irq", l3); if (ret) dev_err(l3->dev, "request_irq failed for %d\n", l3->app_irq); diff --git a/drivers/bus/omap_l3_smx.c b/drivers/bus/omap_l3_smx.c index 597fdaee7315..360a5c0a4ee0 100644 --- a/drivers/bus/omap_l3_smx.c +++ b/drivers/bus/omap_l3_smx.c @@ -251,18 +251,16 @@ static int omap3_l3_probe(struct platform_device *pdev) } l3->debug_irq = platform_get_irq(pdev, 0); - ret = request_irq(l3->debug_irq, omap3_l3_app_irq, - IRQF_DISABLED | IRQF_TRIGGER_RISING, - "l3-debug-irq", l3); + ret = request_irq(l3->debug_irq, omap3_l3_app_irq, IRQF_TRIGGER_RISING, + "l3-debug-irq", l3); if (ret) { dev_err(&pdev->dev, "couldn't request debug irq\n"); goto err1; } l3->app_irq = platform_get_irq(pdev, 1); - ret = request_irq(l3->app_irq, omap3_l3_app_irq, - IRQF_DISABLED | IRQF_TRIGGER_RISING, - "l3-app-irq", l3); + ret = request_irq(l3->app_irq, omap3_l3_app_irq, IRQF_TRIGGER_RISING, + "l3-app-irq", l3); if (ret) { dev_err(&pdev->dev, "couldn't request app irq\n"); goto err2; diff --git a/drivers/mtd/nand/hisi504_nand.c b/drivers/mtd/nand/hisi504_nand.c index 289ad3ac3e80..8dcc7b8fee40 100644 --- a/drivers/mtd/nand/hisi504_nand.c +++ b/drivers/mtd/nand/hisi504_nand.c @@ -758,8 +758,7 @@ static int hisi_nfc_probe(struct platform_device *pdev) hisi_nfc_host_init(host); - ret = devm_request_irq(dev, irq, hinfc_irq_handle, IRQF_DISABLED, - "nandc", host); + ret = devm_request_irq(dev, irq, hinfc_irq_handle, 0x0, "nandc", host); if (ret) { dev_err(dev, "failed to request IRQ\n"); goto err_res; diff --git a/drivers/usb/isp1760/isp1760-core.c b/drivers/usb/isp1760/isp1760-core.c index b9827556455f..5c37f40f6122 100644 --- a/drivers/usb/isp1760/isp1760-core.c +++ b/drivers/usb/isp1760/isp1760-core.c @@ -151,8 +151,7 @@ int isp1760_register(struct resource *mem, int irq, unsigned long irqflags, } if (IS_ENABLED(CONFIG_USB_ISP1761_UDC) && !udc_disabled) { - ret = isp1760_udc_register(isp, irq, irqflags | IRQF_SHARED | - IRQF_DISABLED); + ret = isp1760_udc_register(isp, irq, irqflags | IRQF_SHARED); if (ret < 0) { isp1760_hcd_unregister(&isp->hcd); return ret; diff --git a/drivers/usb/isp1760/isp1760-udc.c b/drivers/usb/isp1760/isp1760-udc.c index 9612d7990565..0b46ff01299f 100644 --- a/drivers/usb/isp1760/isp1760-udc.c +++ b/drivers/usb/isp1760/isp1760-udc.c @@ -1451,8 +1451,8 @@ int isp1760_udc_register(struct isp1760_device *isp, int irq, sprintf(udc->irqname, "%s (udc)", devname); - ret = request_irq(irq, isp1760_udc_irq, IRQF_SHARED | IRQF_DISABLED | - irqflags, udc->irqname, udc); + ret = request_irq(irq, isp1760_udc_irq, IRQF_SHARED | irqflags, + udc->irqname, udc); if (ret < 0) goto error; diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index 3bb01b9a379c..2cee1761c77d 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -39,8 +39,6 @@ * These flags used only by the kernel as part of the * irq handling routines. * - * IRQF_DISABLED - keep irqs disabled when calling the action handler. - * DEPRECATED. This flag is a NOOP and scheduled to be removed * IRQF_SHARED - allow sharing the irq among several devices * IRQF_PROBE_SHARED - set by callers when they expect sharing mismatches to occur * IRQF_TIMER - Flag to mark this interrupt as timer interrupt @@ -58,7 +56,6 @@ * IRQF_EARLY_RESUME - Resume IRQ early during syscore instead of at device * resume time. */ -#define IRQF_DISABLED 0x00000020 #define IRQF_SHARED 0x00000080 #define IRQF_PROBE_SHARED 0x00000100 #define __IRQF_TIMER 0x00000200 -- cgit v1.3-14-g43fede From 1b7047edfcfb257f69e306c9afbab150cb987717 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Wed, 18 Mar 2015 11:01:22 +0000 Subject: genirq: Allow the irqchip state of an IRQ to be save/restored There is a number of cases where a kernel subsystem may want to introspect the state of an interrupt at the irqchip level: - When a peripheral is shared between virtual machines, its interrupt state becomes part of the guest's state, and must be switched accordingly. KVM on arm/arm64 requires this for its guest-visible timer - Some GPIO controllers seem to require peeking into the interrupt controller they are connected to to report their internal state This seem to be a pattern that is common enough for the core code to try and support this without too many horrible hacks. Introduce a pair of accessors (irq_get_irqchip_state/irq_set_irqchip_state) to retrieve the bits that can be of interest to another subsystem: pending, active, and masked. - irq_get_irqchip_state returns the state of the interrupt according to a parameter set to IRQCHIP_STATE_PENDING, IRQCHIP_STATE_ACTIVE, IRQCHIP_STATE_MASKED or IRQCHIP_STATE_LINE_LEVEL. - irq_set_irqchip_state similarly sets the state of the interrupt. Signed-off-by: Marc Zyngier Reviewed-by: Bjorn Andersson Tested-by: Bjorn Andersson Cc: linux-arm-kernel@lists.infradead.org Cc: Abhijeet Dharmapurikar Cc: Stephen Boyd Cc: Phong Vo Cc: Linus Walleij Cc: Tin Huynh Cc: Y Vo Cc: Toan Le Cc: Bjorn Andersson Cc: Jason Cooper Cc: Arnd Bergmann Link: http://lkml.kernel.org/r/1426676484-21812-2-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner --- include/linux/interrupt.h | 14 ++++++++ include/linux/irq.h | 6 ++++ kernel/irq/manage.c | 91 +++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 111 insertions(+) (limited to 'include/linux/interrupt.h') diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index 150dde04cf4f..950ae4501826 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -361,6 +361,20 @@ static inline int disable_irq_wake(unsigned int irq) return irq_set_irq_wake(irq, 0); } +/* + * irq_get_irqchip_state/irq_set_irqchip_state specific flags + */ +enum irqchip_irq_state { + IRQCHIP_STATE_PENDING, /* Is interrupt pending? */ + IRQCHIP_STATE_ACTIVE, /* Is interrupt in progress? */ + IRQCHIP_STATE_MASKED, /* Is interrupt masked? */ + IRQCHIP_STATE_LINE_LEVEL, /* Is IRQ line high? */ +}; + +extern int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which, + bool *state); +extern int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which, + bool state); #ifdef CONFIG_IRQ_FORCED_THREADING extern bool force_irqthreads; diff --git a/include/linux/irq.h b/include/linux/irq.h index d09ec7a1243e..77dd2e7f93f4 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -30,6 +30,7 @@ struct seq_file; struct module; struct msi_msg; +enum irqchip_irq_state; /* * IRQ line status. @@ -324,6 +325,8 @@ static inline irq_hw_number_t irqd_to_hwirq(struct irq_data *d) * irq_request_resources * @irq_compose_msi_msg: optional to compose message content for MSI * @irq_write_msi_msg: optional to write message content for MSI + * @irq_get_irqchip_state: return the internal state of an interrupt + * @irq_set_irqchip_state: set the internal state of a interrupt * @flags: chip specific flags */ struct irq_chip { @@ -363,6 +366,9 @@ struct irq_chip { void (*irq_compose_msi_msg)(struct irq_data *data, struct msi_msg *msg); void (*irq_write_msi_msg)(struct irq_data *data, struct msi_msg *msg); + int (*irq_get_irqchip_state)(struct irq_data *data, enum irqchip_irq_state which, bool *state); + int (*irq_set_irqchip_state)(struct irq_data *data, enum irqchip_irq_state which, bool state); + unsigned long flags; }; diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index c0a1100d911f..e68932bb308e 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -1798,3 +1798,94 @@ int request_percpu_irq(unsigned int irq, irq_handler_t handler, return retval; } + +/** + * irq_get_irqchip_state - returns the irqchip state of a interrupt. + * @irq: Interrupt line that is forwarded to a VM + * @which: One of IRQCHIP_STATE_* the caller wants to know about + * @state: a pointer to a boolean where the state is to be storeed + * + * This call snapshots the internal irqchip state of an + * interrupt, returning into @state the bit corresponding to + * stage @which + * + * This function should be called with preemption disabled if the + * interrupt controller has per-cpu registers. + */ +int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which, + bool *state) +{ + struct irq_desc *desc; + struct irq_data *data; + struct irq_chip *chip; + unsigned long flags; + int err = -EINVAL; + + desc = irq_get_desc_buslock(irq, &flags, 0); + if (!desc) + return err; + + data = irq_desc_get_irq_data(desc); + + do { + chip = irq_data_get_irq_chip(data); + if (chip->irq_get_irqchip_state) + break; +#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY + data = data->parent_data; +#else + data = NULL; +#endif + } while (data); + + if (data) + err = chip->irq_get_irqchip_state(data, which, state); + + irq_put_desc_busunlock(desc, flags); + return err; +} + +/** + * irq_set_irqchip_state - set the state of a forwarded interrupt. + * @irq: Interrupt line that is forwarded to a VM + * @which: State to be restored (one of IRQCHIP_STATE_*) + * @val: Value corresponding to @which + * + * This call sets the internal irqchip state of an interrupt, + * depending on the value of @which. + * + * This function should be called with preemption disabled if the + * interrupt controller has per-cpu registers. + */ +int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which, + bool val) +{ + struct irq_desc *desc; + struct irq_data *data; + struct irq_chip *chip; + unsigned long flags; + int err = -EINVAL; + + desc = irq_get_desc_buslock(irq, &flags, 0); + if (!desc) + return err; + + data = irq_desc_get_irq_data(desc); + + do { + chip = irq_data_get_irq_chip(data); + if (chip->irq_set_irqchip_state) + break; +#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY + data = data->parent_data; +#else + data = NULL; +#endif + } while (data); + + if (data) + err = chip->irq_set_irqchip_state(data, which, val); + + irq_put_desc_busunlock(desc, flags); + return err; +} -- cgit v1.3-14-g43fede