| Message ID | 20231016062831.20630-6-jgross@suse.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 5dd9ad32d7758b1a76742f394acf0eb3ac8a636a |
| Headers | show |
| Series | xen/events: do some cleanups in events_base.c | expand |
On 16.10.23 09:28, Juergen Gross wrote: Hello Juergen > Instead of having a common function for allocating a single IRQ or a > consecutive number of IRQs, split up the functionality into the callers > of xen_allocate_irqs_dynamic(). > > This allows to handle any allocation error in xen_irq_init() gracefully > instead of panicing the system. Let xen_irq_init() return the irq_info > pointer or NULL in case of an allocation error. > > Additionally set the IRQ into irq_info already at allocation time, as > otherwise the IRQ would be '0' (which is a valid IRQ number) until > being set. > > Signed-off-by: Juergen Gross <jgross@suse.com> > --- > drivers/xen/events/events_base.c | 74 +++++++++++++++++++------------- > 1 file changed, 44 insertions(+), 30 deletions(-) > [snip] > @@ -1725,6 +1738,7 @@ void rebind_evtchn_irq(evtchn_port_t evtchn, int irq) > so there should be a proper type */ > BUG_ON(info->type == IRQT_UNBOUND); > > + info->irq = irq; I failed to understand why this is added here. Doesn't irq remain the same, and info->irq remains valid? Could you please clarify. Other changes lgtm. > (void)xen_irq_info_evtchn_setup(irq, evtchn, NULL); > > mutex_unlock(&irq_mapping_update_lock);
On 14.11.23 09:20, Oleksandr Tyshchenko wrote: > > > On 16.10.23 09:28, Juergen Gross wrote: > > > Hello Juergen > >> Instead of having a common function for allocating a single IRQ or a >> consecutive number of IRQs, split up the functionality into the callers >> of xen_allocate_irqs_dynamic(). >> >> This allows to handle any allocation error in xen_irq_init() gracefully >> instead of panicing the system. Let xen_irq_init() return the irq_info >> pointer or NULL in case of an allocation error. >> >> Additionally set the IRQ into irq_info already at allocation time, as >> otherwise the IRQ would be '0' (which is a valid IRQ number) until >> being set. >> >> Signed-off-by: Juergen Gross <jgross@suse.com> >> --- >> drivers/xen/events/events_base.c | 74 +++++++++++++++++++------------- >> 1 file changed, 44 insertions(+), 30 deletions(-) >> > > [snip] > >> @@ -1725,6 +1738,7 @@ void rebind_evtchn_irq(evtchn_port_t evtchn, int irq) >> so there should be a proper type */ >> BUG_ON(info->type == IRQT_UNBOUND); >> >> + info->irq = irq; > > > I failed to understand why this is added here. Doesn't irq remain the > same, and info->irq remains valid? Could you please clarify. The IRQ remains the same, but the event channel could change. This setting of info->irq compensates for the related removal in xen_irq_info_common_setup(). > > Other changes lgtm. Juergen
On 14.11.23 10:35, Juergen Gross wrote: Hello Juergen > On 14.11.23 09:20, Oleksandr Tyshchenko wrote: >> >> >> On 16.10.23 09:28, Juergen Gross wrote: >> >> >> Hello Juergen >> >>> Instead of having a common function for allocating a single IRQ or a >>> consecutive number of IRQs, split up the functionality into the callers >>> of xen_allocate_irqs_dynamic(). >>> >>> This allows to handle any allocation error in xen_irq_init() gracefully >>> instead of panicing the system. Let xen_irq_init() return the irq_info >>> pointer or NULL in case of an allocation error. >>> >>> Additionally set the IRQ into irq_info already at allocation time, as >>> otherwise the IRQ would be '0' (which is a valid IRQ number) until >>> being set. >>> >>> Signed-off-by: Juergen Gross <jgross@suse.com> >>> --- >>> drivers/xen/events/events_base.c | 74 >>> +++++++++++++++++++------------- >>> 1 file changed, 44 insertions(+), 30 deletions(-) >>> >> >> [snip] >> >>> @@ -1725,6 +1738,7 @@ void rebind_evtchn_irq(evtchn_port_t evtchn, >>> int irq) >>> so there should be a proper type */ >>> BUG_ON(info->type == IRQT_UNBOUND); >>> + info->irq = irq; >> >> >> I failed to understand why this is added here. Doesn't irq remain the >> same, and info->irq remains valid? Could you please clarify. > > The IRQ remains the same, but the event channel could change. > > This setting of info->irq compensates for the related removal in > xen_irq_info_common_setup(). Thanks for the clarification, you can add my Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> > >> >> Other changes lgtm. > > > Juergen >
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c index 4ada3b6a4164..58e5549ee1db 100644 --- a/drivers/xen/events/events_base.c +++ b/drivers/xen/events/events_base.c @@ -302,6 +302,13 @@ static void channels_on_cpu_inc(struct irq_info *info) info->is_accounted = 1; } +static void xen_irq_free_desc(unsigned int irq) +{ + /* Legacy IRQ descriptors are managed by the arch. */ + if (irq >= nr_legacy_irqs()) + irq_free_desc(irq); +} + static void delayed_free_irq(struct work_struct *work) { struct irq_info *info = container_of(to_rcu_work(work), struct irq_info, @@ -313,9 +320,7 @@ static void delayed_free_irq(struct work_struct *work) kfree(info); - /* Legacy IRQ descriptors are managed by the arch. */ - if (irq >= nr_legacy_irqs()) - irq_free_desc(irq); + xen_irq_free_desc(irq); } /* Constructors for packed IRQ information. */ @@ -330,7 +335,6 @@ static int xen_irq_info_common_setup(struct irq_info *info, BUG_ON(info->type != IRQT_UNBOUND && info->type != type); info->type = type; - info->irq = irq; info->evtchn = evtchn; info->cpu = cpu; info->mask_reason = EVT_MASK_REASON_EXPLICIT; @@ -730,47 +734,45 @@ void xen_irq_lateeoi(unsigned int irq, unsigned int eoi_flags) } EXPORT_SYMBOL_GPL(xen_irq_lateeoi); -static void xen_irq_init(unsigned irq) +static struct irq_info *xen_irq_init(unsigned int irq) { struct irq_info *info; info = kzalloc(sizeof(*info), GFP_KERNEL); - if (info == NULL) - panic("Unable to allocate metadata for IRQ%d\n", irq); + if (info) { + info->irq = irq; + info->type = IRQT_UNBOUND; + info->refcnt = -1; + INIT_RCU_WORK(&info->rwork, delayed_free_irq); - info->type = IRQT_UNBOUND; - info->refcnt = -1; - INIT_RCU_WORK(&info->rwork, delayed_free_irq); + set_info_for_irq(irq, info); + /* + * Interrupt affinity setting can be immediate. No point + * in delaying it until an interrupt is handled. + */ + irq_set_status_flags(irq, IRQ_MOVE_PCNTXT); - set_info_for_irq(irq, info); - /* - * Interrupt affinity setting can be immediate. No point - * in delaying it until an interrupt is handled. - */ - irq_set_status_flags(irq, IRQ_MOVE_PCNTXT); + INIT_LIST_HEAD(&info->eoi_list); + list_add_tail(&info->list, &xen_irq_list_head); + } - INIT_LIST_HEAD(&info->eoi_list); - list_add_tail(&info->list, &xen_irq_list_head); + return info; } -static int __must_check xen_allocate_irqs_dynamic(int nvec) +static inline int __must_check xen_allocate_irq_dynamic(void) { - int i, irq = irq_alloc_descs(-1, 0, nvec, -1); + int irq = irq_alloc_desc_from(0, -1); if (irq >= 0) { - for (i = 0; i < nvec; i++) - xen_irq_init(irq + i); + if (!xen_irq_init(irq)) { + xen_irq_free_desc(irq); + irq = -1; + } } return irq; } -static inline int __must_check xen_allocate_irq_dynamic(void) -{ - - return xen_allocate_irqs_dynamic(1); -} - static int __must_check xen_allocate_irq_gsi(unsigned gsi) { int irq; @@ -790,7 +792,10 @@ static int __must_check xen_allocate_irq_gsi(unsigned gsi) else irq = irq_alloc_desc_at(gsi, -1); - xen_irq_init(irq); + if (!xen_irq_init(irq)) { + xen_irq_free_desc(irq); + irq = -1; + } return irq; } @@ -960,6 +965,11 @@ static void __unbind_from_irq(unsigned int irq) evtchn_port_t evtchn = evtchn_from_irq(irq); struct irq_info *info = info_for_irq(irq); + if (!info) { + xen_irq_free_desc(irq); + return; + } + if (info->refcnt > 0) { info->refcnt--; if (info->refcnt != 0) @@ -1097,11 +1107,14 @@ int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc, mutex_lock(&irq_mapping_update_lock); - irq = xen_allocate_irqs_dynamic(nvec); + irq = irq_alloc_descs(-1, 0, nvec, -1); if (irq < 0) goto out; for (i = 0; i < nvec; i++) { + if (!xen_irq_init(irq + i)) + goto error_irq; + irq_set_chip_and_handler_name(irq + i, &xen_pirq_chip, handle_edge_irq, name); ret = xen_irq_info_pirq_setup(irq + i, 0, pirq + i, 0, domid, @@ -1725,6 +1738,7 @@ void rebind_evtchn_irq(evtchn_port_t evtchn, int irq) so there should be a proper type */ BUG_ON(info->type == IRQT_UNBOUND); + info->irq = irq; (void)xen_irq_info_evtchn_setup(irq, evtchn, NULL); mutex_unlock(&irq_mapping_update_lock);
Instead of having a common function for allocating a single IRQ or a consecutive number of IRQs, split up the functionality into the callers of xen_allocate_irqs_dynamic(). This allows to handle any allocation error in xen_irq_init() gracefully instead of panicing the system. Let xen_irq_init() return the irq_info pointer or NULL in case of an allocation error. Additionally set the IRQ into irq_info already at allocation time, as otherwise the IRQ would be '0' (which is a valid IRQ number) until being set. Signed-off-by: Juergen Gross <jgross@suse.com> --- drivers/xen/events/events_base.c | 74 +++++++++++++++++++------------- 1 file changed, 44 insertions(+), 30 deletions(-)