| Message ID | 1426676484-21812-2-git-send-email-marc.zyngier@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Mar 18, 2015 at 4:01 AM, Marc Zyngier <marc.zyngier@arm.com> wrote: > 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. > > Reviewed-by: Bjorn Andersson <bjorn.andersson@sonymobile.com> > Tested-by: Bjorn Andersson <bjorn.andersson@sonymobile.com> > Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> > --- Sorry for bothering you Thomas, but we have a couple of driver for the Qualcomm platforms that depends on this patch (the line level part). Could you please have a look at it? Thanks, Bjorn -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 08/04/15 18:48, Bjorn Andersson wrote: > On Wed, Mar 18, 2015 at 4:01 AM, Marc Zyngier <marc.zyngier@arm.com> wrote: >> 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. >> >> Reviewed-by: Bjorn Andersson <bjorn.andersson@sonymobile.com> >> Tested-by: Bjorn Andersson <bjorn.andersson@sonymobile.com> >> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> >> --- > > Sorry for bothering you Thomas, but we have a couple of driver for the > Qualcomm platforms that depends on this patch (the line level part). +1 Couple of Qualcomm board support are left incomplete due to missing drivers using these patches. Would be nice to get this patch mainlined sooner. -srini > Could you please have a look at it? > > Thanks, > Bjorn > -- > To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 13/04/15 17:18, Srinivas Kandagatla wrote: > > > On 08/04/15 18:48, Bjorn Andersson wrote: >> On Wed, Mar 18, 2015 at 4:01 AM, Marc Zyngier <marc.zyngier@arm.com> wrote: >>> 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. >>> >>> Reviewed-by: Bjorn Andersson <bjorn.andersson@sonymobile.com> >>> Tested-by: Bjorn Andersson <bjorn.andersson@sonymobile.com> >>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> >>> --- >> >> Sorry for bothering you Thomas, but we have a couple of driver for the >> Qualcomm platforms that depends on this patch (the line level part). > > +1 > > Couple of Qualcomm board support are left incomplete due to missing > drivers using these patches. > Would be nice to get this patch mainlined sooner. These patches are already in -next. Should everything go according to plan, they should hit 4.1. Thanks, M.
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index 2e88580..011cc64 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -363,6 +363,20 @@ 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 d09ec7a..77dd2e7 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 886d09e..08308e1 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -1766,3 +1766,94 @@ 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; +}