From 18258f7239a61d8929b8e0c7b6d46c446459074c Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sat, 15 Feb 2014 00:55:18 +0000 Subject: genirq: Provide synchronize_hardirq() synchronize_irq() waits for hard irq and threaded handlers to complete before returning. For some special cases we only need to make sure that the hard interrupt part of the irq line is not in progress when we disabled the - possibly shared - interrupt at the device level. A proper use case for this was provided by Russell. The sdhci driver requires some irq triggered functions to be run in thread context. The current implementation of the thread context is a sdio private kthread construct, which has quite some shortcomings. These can be avoided when the thread is directly associated to the device interrupt via the generic threaded irq infrastructure. Though there is a corner case related to run time power management where one side disables the device interrupts at the device level and needs to make sure, that an already running hard interrupt handler has completed before proceeding further. Though that hard interrupt handler might wake the associated thread, which in turn can request the runtime PM to reenable the device. Using synchronize_irq() leads to an immediate deadlock of the irq thread waiting for the PM lock and the synchronize_irq() waiting for the irq thread to complete. Due to the fact that it is sufficient for this case to ensure that no hard irq handler is executing a new function which avoids the check for the thread is required. Add a function, which just monitors the hard irq parts and ignores the threaded handlers. Signed-off-by: Thomas Gleixner Tested-by: Russell King Cc: Chris Ball Acked-by: Peter Zijlstra Link: http://lkml.kernel.org/r/20140215003823.653236081@linutronix.de --- include/linux/hardirq.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h index 12d5f972f23f..cba442ec3c66 100644 --- a/include/linux/hardirq.h +++ b/include/linux/hardirq.h @@ -9,6 +9,7 @@ extern void synchronize_irq(unsigned int irq); +extern void synchronize_hardirq(unsigned int irq); #if defined(CONFIG_TINY_RCU) -- cgit From a92444c6b2225a9115d661c950cb48a22aeace20 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sat, 15 Feb 2014 00:55:19 +0000 Subject: genirq: Provide irq_wake_thread() In course of the sdhci/sdio discussion with Russell about killing the sdio kthread hackery we discovered the need to be able to wake an interrupt thread from software. The rationale for this is, that sdio hardware can lack proper interrupt support for certain features. So the driver needs to poll the status registers, but at the same time it needs to be woken up by an hardware interrupt. To be able to get rid of the home brewn kthread construct of sdio we need a way to wake an irq thread independent of an actual hardware interrupt. Provide an irq_wake_thread() function which wakes up the thread which is associated to a given dev_id. This allows sdio to invoke the irq thread from the hardware irq handler via the IRQ_WAKE_THREAD return value and provides a possibility to wake it via a timer for the polling scenarios. That allows to simplify the sdio logic significantly. Signed-off-by: Thomas Gleixner Cc: Russell King Cc: Chris Ball Acked-by: Peter Zijlstra Link: http://lkml.kernel.org/r/20140215003823.772565780@linutronix.de --- include/linux/interrupt.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index a2678d35b5a2..c7bfac1c4a7b 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -188,6 +188,7 @@ extern void disable_irq(unsigned int irq); extern void disable_percpu_irq(unsigned int irq); extern void enable_irq(unsigned int irq); extern void enable_percpu_irq(unsigned int irq, unsigned int type); +extern void irq_wake_thread(unsigned int irq, void *dev_id); /* The following three functions are for the core kernel use only. */ extern void suspend_device_irqs(void); -- cgit From 792d0018a5fe31ef8ef9d07a7a02081d4abdf6b7 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sun, 23 Feb 2014 21:40:14 +0000 Subject: genirq: Add a kstat helper to increment irq stats There is a common pattern all over the place: kstat_incr_irqs_this_cpu(irq, irq_to_desc(irq)); This results in a call to core code anyway. So provide a function which does the same thing in core. While at it, replace the butt ugly macro with an inline. Signed-off-by: Thomas Gleixner Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20140223212737.422068876@linutronix.de Signed-off-by: Thomas Gleixner --- include/linux/kernel_stat.h | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) (limited to 'include/linux') diff --git a/include/linux/kernel_stat.h b/include/linux/kernel_stat.h index 51c72be4a7c3..54ec7e0a7d72 100644 --- a/include/linux/kernel_stat.h +++ b/include/linux/kernel_stat.h @@ -54,11 +54,13 @@ extern unsigned long long nr_context_switches(void); #include extern unsigned int kstat_irqs_cpu(unsigned int irq, int cpu); -#define kstat_incr_irqs_this_cpu(irqno, DESC) \ -do { \ - __this_cpu_inc(*(DESC)->kstat_irqs); \ - __this_cpu_inc(kstat.irqs_sum); \ -} while (0) +static inline void kstat_incr_irqs_this_cpu(unsigned int irq, struct irq_desc *desc) +{ + __this_cpu_inc(*desc->kstat_irqs); + __this_cpu_inc(kstat.irqs_sum); +} + +extern void kstat_incr_irq_this_cpu(unsigned int irq); static inline void kstat_incr_softirqs_this_cpu(unsigned int irq) { -- cgit From 8f945a3325bbe0dd651e2f496a53df9b06fc6d07 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sun, 23 Feb 2014 21:40:23 +0000 Subject: genirq: Move kstat_incr_irqs_this_cpu() to core No more users outside the core code. Put it into the poison cabinet. That also gets rid of the linux/irq.h include in kernel_stat.h Signed-off-by: Thomas Gleixner Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20140223212739.124207133@linutronix.de Signed-off-by: Thomas Gleixner --- include/linux/kernel_stat.h | 8 -------- 1 file changed, 8 deletions(-) (limited to 'include/linux') diff --git a/include/linux/kernel_stat.h b/include/linux/kernel_stat.h index 54ec7e0a7d72..c3fbda7690d6 100644 --- a/include/linux/kernel_stat.h +++ b/include/linux/kernel_stat.h @@ -51,15 +51,7 @@ DECLARE_PER_CPU(struct kernel_cpustat, kernel_cpustat); extern unsigned long long nr_context_switches(void); -#include extern unsigned int kstat_irqs_cpu(unsigned int irq, int cpu); - -static inline void kstat_incr_irqs_this_cpu(unsigned int irq, struct irq_desc *desc) -{ - __this_cpu_inc(*desc->kstat_irqs); - __this_cpu_inc(kstat.irqs_sum); -} - extern void kstat_incr_irq_this_cpu(unsigned int irq); static inline void kstat_incr_softirqs_this_cpu(unsigned int irq) -- cgit From c1bacbae8192dd2a9ebadd22d793b68054f6c6e5 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sat, 8 Mar 2014 08:59:58 +0100 Subject: genirq: Provide irq_request/release_resources chip callbacks For certain irq types, e.g. gpios, it's necessary to request resources before starting up the irq. This might fail so we cannot use the irq_startup() callback because we might call the irq_set_type() callback before that which does not make sense when the resource is not available. Calling irq_startup() before irq_set_type() can lead to spurious interrupts which is not desired either. Signed-off-by: Thomas Gleixner Cc: Jean-Jacques Hiblot Cc: Grant Likely Cc: linux-arm-kernel@lists.infradead.org Reviewed-by: Linus Walleij Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1403080857160.18573@ionos.tec.linutronix.de Signed-off-by: Thomas Gleixner --- include/linux/irq.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/linux') diff --git a/include/linux/irq.h b/include/linux/irq.h index 7dc10036eff5..e675971bdc3f 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -303,6 +303,10 @@ static inline irq_hw_number_t irqd_to_hwirq(struct irq_data *d) * @irq_pm_shutdown: function called from core code on shutdown once per chip * @irq_calc_mask: Optional function to set irq_data.mask for special cases * @irq_print_chip: optional to print special chip info in show_interrupts + * @irq_request_resources: optional to request resources before calling + * any other callback related to this irq + * @irq_release_resources: optional to release resources acquired with + * irq_request_resources * @flags: chip specific flags */ struct irq_chip { @@ -336,6 +340,8 @@ struct irq_chip { void (*irq_calc_mask)(struct irq_data *data); void (*irq_print_chip)(struct irq_data *data, struct seq_file *p); + int (*irq_request_resources)(struct irq_data *data); + void (*irq_release_resources)(struct irq_data *data); unsigned long flags; }; -- cgit From 4f6e4f71c9d39cf49e0cb1be5b7721db5fbe92ac Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 13 Mar 2014 15:32:47 +0100 Subject: genirq: Document IRQCHIP_ONESHOT_SAFE flag Add missing documentation of the flag. Signed-off-by: Thomas Gleixner --- include/linux/irq.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/irq.h b/include/linux/irq.h index e675971bdc3f..67ace7aa7947 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -355,6 +355,7 @@ struct irq_chip { * IRQCHIP_ONOFFLINE_ENABLED: Only call irq_on/off_line callbacks * when irq enabled * IRQCHIP_SKIP_SET_WAKE: Skip chip.irq_set_wake(), for this irq chip + * IRQCHIP_ONESHOT_SAFE: One shot does not require mask/unmask */ enum { IRQCHIP_SET_TYPE_MASKED = (1 << 0), -- cgit From 328a4978df833249b099c9875738d7b72042ffe1 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 13 Mar 2014 19:03:51 +0100 Subject: genirq: Add a new IRQCHIP_EOI_THREADED flag The flag is necessary for interrupt chips which require an ACK/EOI after the handler has run. In case of threaded handlers this needs to happen after the threaded handler has completed before the unmask of the interrupt. The flag is only unseful in combination with the handle_fasteoi_irq flow control handler. It can be combined with the flag IRQCHIP_EOI_IF_HANDLED, so the EOI is not issued when the interrupt is disabled or in progress. Tested-by: Hans de Goede Reviewed-by: Hans de Goede Cc: linux-arm-kernel@lists.infradead.org Cc: linux-sunxi@googlegroups.com Cc: Maxime Ripard Link: http://lkml.kernel.org/r/1394733834-26839-2-git-send-email-hdegoede@redhat.com Signed-off-by: Thomas Gleixner --- include/linux/irq.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux') diff --git a/include/linux/irq.h b/include/linux/irq.h index 67ace7aa7947..d278838908cb 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -356,6 +356,7 @@ struct irq_chip { * when irq enabled * IRQCHIP_SKIP_SET_WAKE: Skip chip.irq_set_wake(), for this irq chip * IRQCHIP_ONESHOT_SAFE: One shot does not require mask/unmask + * IRQCHIP_EOI_THREADED: Chip requires eoi() on unmask in threaded mode */ enum { IRQCHIP_SET_TYPE_MASKED = (1 << 0), @@ -364,6 +365,7 @@ enum { IRQCHIP_ONOFFLINE_ENABLED = (1 << 3), IRQCHIP_SKIP_SET_WAKE = (1 << 4), IRQCHIP_ONESHOT_SAFE = (1 << 5), + IRQCHIP_EOI_THREADED = (1 << 6), }; /* This include will go away once we isolated irq_desc usage to core code */ -- cgit