| Message ID | 1298671177-19572-3-git-send-email-meador_inge@mentor.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
> diff --git a/arch/powerpc/include/asm/mpic.h b/arch/powerpc/include/asm/mpic.h > index e000cce..7e1be12 100644 > --- a/arch/powerpc/include/asm/mpic.h > +++ b/arch/powerpc/include/asm/mpic.h > @@ -325,6 +325,8 @@ struct mpic > #ifdef CONFIG_PM > struct mpic_irq_save *save_data; > #endif > + > + int cpu; > }; Why ? The MPIC isn't specifically associated with a CPU and whatever we pick as default during boot isn't relevant later on, so I don't see why we should have global permanent state here. > > +static inline void mpic_init_vector(struct mpic *mpic, int source) > +{ > + /* start with vector = source number, and masked */ > + u32 vecpri = MPIC_VECPRI_MASK | source | (8 << MPIC_VECPRI_PRIORITY_SHIFT); > + > + /* init hw */ > + mpic_irq_write(source, MPIC_INFO(IRQ_VECTOR_PRI), vecpri); > + mpic_irq_write(source, MPIC_INFO(IRQ_DESTINATION), 1 << mpic->cpu); > +} Just pass the CPU as an argument... but better... just don't do that, put the code back where it was and ... see below :-) > /* Check if we have one of those nice broken MPICs with a flipped endian on > @@ -622,6 +631,14 @@ static unsigned int mpic_is_ipi(struct mpic *mpic, unsigned int irq) > return (src >= mpic->ipi_vecs[0] && src <= mpic->ipi_vecs[3]); > } > > +/* Determine if the linux irq is a timer interrupt */ > +static unsigned int mpic_is_timer_interrupt(struct mpic *mpic, unsigned int irq) > +{ > + unsigned int src = mpic_irq_to_hw(irq); > + > + return (src >= mpic->timer_vecs[0] && src <= mpic->timer_vecs[3]); > +} > + > > /* Convert a cpu mask from logical to physical cpu numbers. */ > static inline u32 mpic_physmask(u32 cpumask) > @@ -967,6 +984,15 @@ static int mpic_host_map(struct irq_host *h, unsigned int virq, > if (hw >= mpic->irq_count) > return -EINVAL; > > + /* If the MPIC was reset, then all vectors have already been > + * initialized. Otherwise, the appropriate vector needs to be > + * initialized here to ensure that only used sources are setup with > + * a vector. > + */ > + if (mpic->flags & MPIC_NO_RESET) > + if (!(mpic_is_ipi(mpic, hw) || mpic_is_timer_interrupt(mpic, hw))) > + mpic_init_vector(mpic, hw); > + The above isn't useful. Of those two registers you want to initialize, afaik, one (the destination) will be initialized by the core calling into set_affinity when the interrupt is requested, and the other one is partially initialized in set_type, I'd say just modify set_type to initialize the source as well, and problem solved, no ? Or is there a chance that the interrupt was left unmasked ? I think it would be kosher to mask it in set_type unconditionally, I don't think it's ever supposed to be called for an enabled interrupt. > mpic_msi_reserve_hwirq(mpic, hw); > > /* Default chip */ > @@ -1033,6 +1059,11 @@ static struct irq_host_ops mpic_host_ops = { > .xlate = mpic_host_xlate, > }; > > +static int mpic_reset_prohibited(struct device_node *node) > +{ > + return node && of_get_property(node, "pic-no-reset", NULL); > +} > + > /* > * Exported functions > */ > @@ -1153,7 +1184,16 @@ struct mpic * __init mpic_alloc(struct device_node *node, > mpic_map(mpic, node, paddr, &mpic->tmregs, MPIC_INFO(TIMER_BASE), 0x1000); > > /* Reset */ > - if (flags & MPIC_WANTS_RESET) { > + > + /* When using a device-node, reset requests are only honored if the MPIC > + * is allowed to reset. > + */ > + if (mpic_reset_prohibited(node)) { > + mpic->flags |= MPIC_NO_RESET; > + } No { } for single line nested statements > + if ((flags & MPIC_WANTS_RESET) && !(mpic->flags & MPIC_NO_RESET)) { > + printk(KERN_DEBUG "mpic: Resetting\n"); > mpic_write(mpic->gregs, MPIC_INFO(GREG_GLOBAL_CONF_0), > mpic_read(mpic->gregs, MPIC_INFO(GREG_GLOBAL_CONF_0)) > | MPIC_GREG_GCONF_RESET); > @@ -1270,7 +1310,6 @@ void __init mpic_set_default_senses(struct mpic *mpic, u8 *senses, int count) > void __init mpic_init(struct mpic *mpic) > { > int i; > - int cpu; > > BUG_ON(mpic->num_sources == 0); > > @@ -1314,21 +1353,17 @@ void __init mpic_init(struct mpic *mpic) > mpic_pasemi_msi_init(mpic); > > if (mpic->flags & MPIC_PRIMARY) > - cpu = hard_smp_processor_id(); > + mpic->cpu = hard_smp_processor_id(); > else > - cpu = 0; > + mpic->cpu = 0; Get rid of all that. > - for (i = 0; i < mpic->num_sources; i++) { > - /* start with vector = source number, and masked */ > - u32 vecpri = MPIC_VECPRI_MASK | i | > - (8 << MPIC_VECPRI_PRIORITY_SHIFT); > - > - /* check if protected */ > - if (mpic->protected && test_bit(i, mpic->protected)) > - continue; > - /* init hw */ > - mpic_irq_write(i, MPIC_INFO(IRQ_VECTOR_PRI), vecpri); > - mpic_irq_write(i, MPIC_INFO(IRQ_DESTINATION), 1 << cpu); > + if (!(mpic->flags & MPIC_NO_RESET)) { > + for (i = 0; i < mpic->num_sources; i++) { > + /* check if protected */ > + if (mpic->protected && test_bit(i, mpic->protected)) > + continue; > + mpic_init_vector(mpic, i); > + } > } > > /* Init spurious vector */ Cheers, Ben.
On 03/01/2011 09:22 PM, Benjamin Herrenschmidt wrote: > >> diff --git a/arch/powerpc/include/asm/mpic.h b/arch/powerpc/include/asm/mpic.h >> index e000cce..7e1be12 100644 >> --- a/arch/powerpc/include/asm/mpic.h >> +++ b/arch/powerpc/include/asm/mpic.h >> @@ -325,6 +325,8 @@ struct mpic >> #ifdef CONFIG_PM >> struct mpic_irq_save *save_data; >> #endif >> + >> + int cpu; >> }; > > Why ? The MPIC isn't specifically associated with a CPU and whatever we > pick as default during boot isn't relevant later on, so I don't see why > we should have global permanent state here. I agree. I shouldn't have cached that. We should probably introduce a helper function to get the cpuid, though. The: unsigned int cpu = 0; if (mpic->flags & MPIC_PRIMARY) cpu = hard_smp_processor_id(); code is scattered in three places: '_mpic_cpu_write', '_mpic_cpu_read', and 'mpic_init'. >> /* Check if we have one of those nice broken MPICs with a flipped endian on >> @@ -622,6 +631,14 @@ static unsigned int mpic_is_ipi(struct mpic *mpic, unsigned int irq) >> return (src>= mpic->ipi_vecs[0]&& src<= mpic->ipi_vecs[3]); >> } >> >> +/* Determine if the linux irq is a timer interrupt */ >> +static unsigned int mpic_is_timer_interrupt(struct mpic *mpic, unsigned int irq) >> +{ >> + unsigned int src = mpic_irq_to_hw(irq); >> + >> + return (src>= mpic->timer_vecs[0]&& src<= mpic->timer_vecs[3]); >> +} >> + >> >> /* Convert a cpu mask from logical to physical cpu numbers. */ >> static inline u32 mpic_physmask(u32 cpumask) >> @@ -967,6 +984,15 @@ static int mpic_host_map(struct irq_host *h, unsigned int virq, >> if (hw>= mpic->irq_count) >> return -EINVAL; >> >> + /* If the MPIC was reset, then all vectors have already been >> + * initialized. Otherwise, the appropriate vector needs to be >> + * initialized here to ensure that only used sources are setup with >> + * a vector. >> + */ >> + if (mpic->flags& MPIC_NO_RESET) >> + if (!(mpic_is_ipi(mpic, hw) || mpic_is_timer_interrupt(mpic, hw))) >> + mpic_init_vector(mpic, hw); >> + > > The above isn't useful. Of those two registers you want to initialize, > afaik, one (the destination) will be initialized by the core calling > into set_affinity when the interrupt is requested, and the other one is AFAIK, we can't rely on 'set_affinity' always being called. I don't think it is called at all when !defined(CONFIG_SMP) and if it was, then that would be an error: /* include/linux/irq.h */ #else /* CONFIG_SMP */ static inline int irq_set_affinity(unsigned int irq, const struct cpumask *m) { return -EINVAL; } > partially initialized in set_type, I'd say just modify set_type to > initialize the source as well, and problem solved, no ? The priority has to be initialized as well. They could both be done in 'mpic_set_irq_type', but that seems like a weird place since it has nothing to do with actually setting the type. Since we already have 'mpic_irq_set_priority' and 'mpic_set_vector', perhaps a better option is to add 'mpic_set_destination' and put the following in 'mpic_host_map' (using the cpuid helper function suggested above): /* Lazy source init when MPIC_NO_RESET */ if (!mpic_is_ipi(mpic, hw) && (mpic->flags & MPIC_NO_RESET)) { mpic_set_vector(virq, hw); mpic_set_destination(virq, mpic_cpuid(mpic)); mpic_irq_set_priority(virq, 8); } It is more overhead, but it reads well. Thoughts? > Or is there a chance that the interrupt was left unmasked ? There shouldn't be. The original idea was that either the boot program would leave it masked or one of the AMP OSes would boot without 'pic-no-reset', which would mask everything. Most likely the boot program. > I think it would be kosher to mask it in set_type unconditionally, I don't think it's ever supposed > to be called for an enabled interrupt. I will look into that. Thanks,
On Thu, 2011-03-10 at 11:23 -0600, Meador Inge wrote: > I agree. I shouldn't have cached that. We should probably introduce a > helper function to get the cpuid, though. The: > > unsigned int cpu = 0; > > if (mpic->flags & MPIC_PRIMARY) > cpu = hard_smp_processor_id(); > > code is scattered in three places: '_mpic_cpu_write', '_mpic_cpu_read', > and 'mpic_init'. Right, but that code must act on the current CPU, not a cached per-MPIC variant. Doing a helper to factor the above 2 lines is fine if you wish to do so but then make it a separate patch. Cheers, Ben.
On Thu, 2011-03-10 at 11:23 -0600, Meador Inge wrote: > AFAIK, we can't rely on 'set_affinity' always being called. I don't > think it is called at all when !defined(CONFIG_SMP) and if it was, > then that would be an error: > > /* include/linux/irq.h */ > > #else /* CONFIG_SMP */ > > static inline int irq_set_affinity(unsigned int irq, > const struct cpumask *m) > { > return -EINVAL; > } You are right. We do need to set a sane default then. > > partially initialized in set_type, I'd say just modify set_type to > > initialize the source as well, and problem solved, no ? > > The priority has to be initialized as well. They could both be done > in > 'mpic_set_irq_type', but that seems like a weird place since it has > nothing to do with actually setting the type. > > Since we already have 'mpic_irq_set_priority' and 'mpic_set_vector', > perhaps a better option is to add 'mpic_set_destination' and put the > following in 'mpic_host_map' (using the cpuid helper function > suggested > above): > > /* Lazy source init when MPIC_NO_RESET */ > if (!mpic_is_ipi(mpic, hw) && (mpic->flags & MPIC_NO_RESET)) { > mpic_set_vector(virq, hw); > mpic_set_destination(virq, mpic_cpuid(mpic)); > mpic_irq_set_priority(virq, 8); > } > > It is more overhead, but it reads well. Thoughts? No objection. Cheers, Ben.
diff --git a/arch/powerpc/include/asm/mpic.h b/arch/powerpc/include/asm/mpic.h index e000cce..7e1be12 100644 --- a/arch/powerpc/include/asm/mpic.h +++ b/arch/powerpc/include/asm/mpic.h @@ -325,6 +325,8 @@ struct mpic #ifdef CONFIG_PM struct mpic_irq_save *save_data; #endif + + int cpu; }; /* @@ -367,6 +369,10 @@ struct mpic #define MPIC_SINGLE_DEST_CPU 0x00001000 /* Enable CoreInt delivery of interrupts */ #define MPIC_ENABLE_COREINT 0x00002000 +/* Disable resetting of the MPIC. + * NOTE: This flag trumps MPIC_WANTS_RESET. + */ +#define MPIC_NO_RESET 0x00004000 /* MPIC HW modification ID */ #define MPIC_REGSET_MASK 0xf0000000 diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c index b0c8469..eac1a3b 100644 --- a/arch/powerpc/sysdev/mpic.c +++ b/arch/powerpc/sysdev/mpic.c @@ -308,6 +308,15 @@ static inline void mpic_map(struct mpic *mpic, struct device_node *node, #define mpic_map(m,n,p,b,o,s) _mpic_map_mmio(m,p,b,o,s) #endif /* !CONFIG_PPC_DCR */ +static inline void mpic_init_vector(struct mpic *mpic, int source) +{ + /* start with vector = source number, and masked */ + u32 vecpri = MPIC_VECPRI_MASK | source | (8 << MPIC_VECPRI_PRIORITY_SHIFT); + + /* init hw */ + mpic_irq_write(source, MPIC_INFO(IRQ_VECTOR_PRI), vecpri); + mpic_irq_write(source, MPIC_INFO(IRQ_DESTINATION), 1 << mpic->cpu); +} /* Check if we have one of those nice broken MPICs with a flipped endian on @@ -622,6 +631,14 @@ static unsigned int mpic_is_ipi(struct mpic *mpic, unsigned int irq) return (src >= mpic->ipi_vecs[0] && src <= mpic->ipi_vecs[3]); } +/* Determine if the linux irq is a timer interrupt */ +static unsigned int mpic_is_timer_interrupt(struct mpic *mpic, unsigned int irq) +{ + unsigned int src = mpic_irq_to_hw(irq); + + return (src >= mpic->timer_vecs[0] && src <= mpic->timer_vecs[3]); +} + /* Convert a cpu mask from logical to physical cpu numbers. */ static inline u32 mpic_physmask(u32 cpumask) @@ -967,6 +984,15 @@ static int mpic_host_map(struct irq_host *h, unsigned int virq, if (hw >= mpic->irq_count) return -EINVAL; + /* If the MPIC was reset, then all vectors have already been + * initialized. Otherwise, the appropriate vector needs to be + * initialized here to ensure that only used sources are setup with + * a vector. + */ + if (mpic->flags & MPIC_NO_RESET) + if (!(mpic_is_ipi(mpic, hw) || mpic_is_timer_interrupt(mpic, hw))) + mpic_init_vector(mpic, hw); + mpic_msi_reserve_hwirq(mpic, hw); /* Default chip */ @@ -1033,6 +1059,11 @@ static struct irq_host_ops mpic_host_ops = { .xlate = mpic_host_xlate, }; +static int mpic_reset_prohibited(struct device_node *node) +{ + return node && of_get_property(node, "pic-no-reset", NULL); +} + /* * Exported functions */ @@ -1153,7 +1184,16 @@ struct mpic * __init mpic_alloc(struct device_node *node, mpic_map(mpic, node, paddr, &mpic->tmregs, MPIC_INFO(TIMER_BASE), 0x1000); /* Reset */ - if (flags & MPIC_WANTS_RESET) { + + /* When using a device-node, reset requests are only honored if the MPIC + * is allowed to reset. + */ + if (mpic_reset_prohibited(node)) { + mpic->flags |= MPIC_NO_RESET; + } + + if ((flags & MPIC_WANTS_RESET) && !(mpic->flags & MPIC_NO_RESET)) { + printk(KERN_DEBUG "mpic: Resetting\n"); mpic_write(mpic->gregs, MPIC_INFO(GREG_GLOBAL_CONF_0), mpic_read(mpic->gregs, MPIC_INFO(GREG_GLOBAL_CONF_0)) | MPIC_GREG_GCONF_RESET); @@ -1270,7 +1310,6 @@ void __init mpic_set_default_senses(struct mpic *mpic, u8 *senses, int count) void __init mpic_init(struct mpic *mpic) { int i; - int cpu; BUG_ON(mpic->num_sources == 0); @@ -1314,21 +1353,17 @@ void __init mpic_init(struct mpic *mpic) mpic_pasemi_msi_init(mpic); if (mpic->flags & MPIC_PRIMARY) - cpu = hard_smp_processor_id(); + mpic->cpu = hard_smp_processor_id(); else - cpu = 0; + mpic->cpu = 0; - for (i = 0; i < mpic->num_sources; i++) { - /* start with vector = source number, and masked */ - u32 vecpri = MPIC_VECPRI_MASK | i | - (8 << MPIC_VECPRI_PRIORITY_SHIFT); - - /* check if protected */ - if (mpic->protected && test_bit(i, mpic->protected)) - continue; - /* init hw */ - mpic_irq_write(i, MPIC_INFO(IRQ_VECTOR_PRI), vecpri); - mpic_irq_write(i, MPIC_INFO(IRQ_DESTINATION), 1 << cpu); + if (!(mpic->flags & MPIC_NO_RESET)) { + for (i = 0; i < mpic->num_sources; i++) { + /* check if protected */ + if (mpic->protected && test_bit(i, mpic->protected)) + continue; + mpic_init_vector(mpic, i); + } } /* Init spurious vector */
This property, defined in the Open PIC binding, tells the kernel not to use the reset bit in the global configuration register. Additionally, its presence mandates that only sources which are actually used (i.e. appear in the device tree) should have their VECPRI bits initialized. Although, "pic-no-reset" can be used for the same use cases that "protected-sources" is covering, the "protected-sources" implementation was left completely intact. This is a more pragmatic approach as there are already several existing systems which use protected sources. If "pic-no-reset" *and* "protected-sources" are both used, however, then "pic-no-reset" takes precedence in terms of the init behavior and the sanity checks done by protected sources will still take place. Signed-off-by: Meador Inge <meador_inge@mentor.com> Cc: Hollis Blanchard <hollis_blanchard@mentor.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> --- arch/powerpc/include/asm/mpic.h | 6 +++ arch/powerpc/sysdev/mpic.c | 67 +++++++++++++++++++++++++++++--------- 2 files changed, 57 insertions(+), 16 deletions(-)