On 07/06/17 17:09, Tim Harvey wrote: > On Mon, Apr 24, 2017 at 6:05 AM, Linus Walleij <linus.walleij@xxxxxxxxxx> wrote: >> Sorry for top posting but we need to loop in Bjorn Helgass and the >> linux-pci mailing list on this patch, at least so they see it, and can >> recognize similar cases in the future. >> >> (The patch set if very nice.) >> >> Yours, >> Linus Walleij >> >> On Tue, Apr 11, 2017 at 7:21 PM, David Daney <david.daney@xxxxxxxxxx> wrote: >>> For an already existing irqdomain hierarchy, as might be obtained via >>> a call to pci_enable_msix_range(), a PCI driver wishing to add an >>> additional irqdomain to the hierarchy needs to be able to insert the >>> irqdomain to that already initialized hierarchy. Calling >>> irq_domain_create_hierarchy() allows the new irqdomain to be created, >>> but no existing code allows for initializing the associated irq_data. >>> >>> Add a couple of helper functions (irq_domain_push_irq() and >>> irq_domain_pop_irq()) to initialize the irq_data for the new >>> irqdomain added to an existing hierarchy. >>> >>> Signed-off-by: David Daney <david.daney@xxxxxxxxxx> >>> --- >>> include/linux/irqdomain.h | 3 + >>> kernel/irq/irqdomain.c | 178 ++++++++++++++++++++++++++++++++++++++++++++++ >>> 2 files changed, 181 insertions(+) >>> >>> diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h >>> index 9f36160..0316846 100644 >>> --- a/include/linux/irqdomain.h >>> +++ b/include/linux/irqdomain.h >>> @@ -425,6 +425,9 @@ extern void irq_domain_free_irqs_common(struct irq_domain *domain, >>> extern void irq_domain_free_irqs_top(struct irq_domain *domain, >>> unsigned int virq, unsigned int nr_irqs); >>> >>> +extern int irq_domain_push_irq(struct irq_domain *domain, int virq, void *arg); >>> +extern int irq_domain_pop_irq(struct irq_domain *domain, int virq); >>> + >>> extern int irq_domain_alloc_irqs_parent(struct irq_domain *domain, >>> unsigned int irq_base, >>> unsigned int nr_irqs, void *arg); >>> diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c >>> index 31805f2..ea9d30d 100644 >>> --- a/kernel/irq/irqdomain.c >>> +++ b/kernel/irq/irqdomain.c >>> @@ -1304,6 +1304,184 @@ int __irq_domain_alloc_irqs(struct irq_domain *domain, int irq_base, >>> return ret; >>> } >>> >>> +/* The irq_data was moved, fix the revmap to refer to the new location */ >>> +static void irq_domain_fix_revmap(struct irq_data *d) >>> +{ >>> + void **slot; >>> + >>> + if (d->hwirq < d->domain->revmap_size) >>> + return; /* Not using radix tree. */ >>> + >>> + /* Fix up the revmap. */ >>> + mutex_lock(&revmap_trees_mutex); >>> + slot = radix_tree_lookup_slot(&d->domain->revmap_tree, d->hwirq); >>> + if (slot) >>> + radix_tree_replace_slot(&d->domain->revmap_tree, slot, d); >>> + mutex_unlock(&revmap_trees_mutex); >>> +} >>> + >>> +/** >>> + * irq_domain_push_irq() - Push a domain in to the top of a hierarchy. >>> + * @domain: Domain to push. >>> + * @virq: Irq to push the domain in to. >>> + * @arg: Passed to the irq_domain_ops alloc() function. >>> + * >>> + * For an already existing irqdomain hierarchy, as might be obtained >>> + * via a call to pci_enable_msix(), add an additional domain to the >>> + * head of the processing chain. Must be called before request_irq() >>> + * has been called. >>> + */ >>> +int irq_domain_push_irq(struct irq_domain *domain, int virq, void *arg) >>> +{ >>> + struct irq_data *child_irq_data; >>> + struct irq_data *root_irq_data = irq_get_irq_data(virq); >>> + struct irq_desc *desc; >>> + int rv = 0; >>> + >>> + /* >>> + * Check that no action has been set, which indicates the virq >>> + * is in a state where this function doesn't have to deal with >>> + * races between interrupt handling and maintaining the >>> + * hierarchy. This will catch gross misuse. Attempting to >>> + * make the check race free would require holding locks across >>> + * calls to struct irq_domain_ops->alloc(), which could lead >>> + * to deadlock, so we just do a simple check before starting. >>> + */ >>> + desc = irq_to_desc(virq); >>> + if (!desc) >>> + return -EINVAL; >>> + if (WARN_ON(desc->action)) >>> + return -EBUSY; >>> + >>> + if (domain == NULL) >>> + return -EINVAL; >>> + >>> + if (WARN_ON(!domain->ops->alloc)) >>> + return -EINVAL; >>> + >>> + if (!root_irq_data) >>> + return -EINVAL; >>> + >>> + child_irq_data = kzalloc_node(sizeof(*child_irq_data), GFP_KERNEL, >>> + irq_data_get_node(root_irq_data)); >>> + if (!child_irq_data) >>> + return -ENOMEM; >>> + >>> + mutex_lock(&irq_domain_mutex); >>> + >>> + /* Copy the original irq_data. */ >>> + *child_irq_data = *root_irq_data; >>> + >>> + irq_domain_fix_revmap(child_irq_data); >>> + >>> + /* >>> + * Overwrite the root_irq_data, which is embedded in struct >>> + * irq_desc, with values for this domain. >>> + */ >>> + root_irq_data->parent_data = child_irq_data; >>> + root_irq_data->domain = domain; >>> + root_irq_data->mask = 0; >>> + root_irq_data->hwirq = 0; >>> + root_irq_data->chip = NULL; >>> + root_irq_data->chip_data = NULL; >>> + rv = domain->ops->alloc(domain, virq, 1, arg); >>> + if (rv) { >>> + /* Restore the original irq_data. */ >>> + *root_irq_data = *child_irq_data; >>> + irq_domain_fix_revmap(root_irq_data); >>> + goto error; >>> + } >>> + >>> + if (root_irq_data->hwirq < domain->revmap_size) { >>> + domain->linear_revmap[root_irq_data->hwirq] = virq; >>> + } else { >>> + mutex_lock(&revmap_trees_mutex); >>> + radix_tree_insert(&domain->revmap_tree, >>> + root_irq_data->hwirq, root_irq_data); >>> + mutex_unlock(&revmap_trees_mutex); >>> + } >>> +error: >>> + mutex_unlock(&irq_domain_mutex); >>> + >>> + return rv; >>> +} >>> +EXPORT_SYMBOL_GPL(irq_domain_push_irq); >>> + >>> +/** >>> + * irq_domain_pop_irq() - Remove a domain from the top of a hierarchy. >>> + * @domain: Domain to remove. >>> + * @virq: Irq to remove the domain from. >>> + * >>> + * Undo the effects of a call to irq_domain_push_irq(). Must be >>> + * called either before request_irq() or after free_irq(). >>> + */ >>> +int irq_domain_pop_irq(struct irq_domain *domain, int virq) >>> +{ >>> + struct irq_data *root_irq_data = irq_get_irq_data(virq); >>> + struct irq_data *child_irq_data; >>> + struct irq_data *tmp_irq_data; >>> + struct irq_desc *desc; >>> + >>> + /* >>> + * Check that no action is set, which indicates the virq is in >>> + * a state where this function doesn't have to deal with races >>> + * between interrupt handling and maintaining the hierarchy. >>> + * This will catch gross misuse. Attempting to make the check >>> + * race free would require holding locks across calls to >>> + * struct irq_domain_ops->free(), which could lead to >>> + * deadlock, so we just do a simple check before starting. >>> + */ >>> + desc = irq_to_desc(virq); >>> + if (!desc) >>> + return -EINVAL; >>> + if (WARN_ON(desc->action)) >>> + return -EBUSY; >>> + >>> + if (domain == NULL) >>> + return -EINVAL; >>> + >>> + if (!root_irq_data) >>> + return -EINVAL; >>> + >>> + tmp_irq_data = irq_domain_get_irq_data(domain, virq); >>> + >>> + /* We can only "pop" if this domain is at the top of the list */ >>> + if (WARN_ON(root_irq_data != tmp_irq_data)) >>> + return -EINVAL; >>> + >>> + if (WARN_ON(root_irq_data->domain != domain)) >>> + return -EINVAL; >>> + >>> + child_irq_data = root_irq_data->parent_data; >>> + if (WARN_ON(!child_irq_data)) >>> + return -EINVAL; >>> + >>> + mutex_lock(&irq_domain_mutex); >>> + >>> + root_irq_data->parent_data = NULL; >>> + >>> + if (root_irq_data->hwirq >= domain->revmap_size) { >>> + mutex_lock(&revmap_trees_mutex); >>> + radix_tree_delete(&domain->revmap_tree, root_irq_data->hwirq); >>> + mutex_unlock(&revmap_trees_mutex); >>> + } >>> + >>> + if (domain->ops->free) >>> + domain->ops->free(domain, virq, 1); >>> + >>> + /* Restore the original irq_data. */ >>> + *root_irq_data = *child_irq_data; >>> + >>> + irq_domain_fix_revmap(root_irq_data); >>> + >>> + mutex_unlock(&irq_domain_mutex); >>> + >>> + kfree(child_irq_data); >>> + >>> + return 0; >>> +} >>> +EXPORT_SYMBOL_GPL(irq_domain_pop_irq); >>> + >>> /** >>> * irq_domain_free_irqs - Free IRQ number and associated data structures >>> * @virq: base IRQ number >>> -- >>> 1.8.3.1 >>> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-gpio" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html > > Linus, > > It looks like we are still waiting on ACK's for this from the IRQ > folk. Are the right people cc'd? Seem's like there's been an adequate > review period with no response. Yup, I've been fairly busy with some other Cavium related stuff. I'll get on it shortly... Thanks, M. -- Jazz is not dead. It just smells funny... -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html