[RFC 08/10] irqdomain: Refactor irq_domain_associate_many()
Mike Qiu
qiudayu at linux.vnet.ibm.com
Tue Jun 18 13:09:07 EST 2013
于 2013/6/10 8:49, Grant Likely 写道:
> Originally, irq_domain_associate_many() was designed to unwind the
> mapped irqs on a failure of any individual association. However, that
> proved to be a problem with certain IRQ controllers. Some of them only
> support a subset of irqs, and will fail when attempting to map a
> reserved IRQ. In those cases we want to map as many IRQs as possible, so
> instead it is better for irq_domain_associate_many() to make a
> best-effort attempt to map irqs, but not fail if any or all of them
> don't succeed. If a caller really cares about how many irqs got
> associated, then it should instead go back and check that all of the
> irqs is cares about were mapped.
>
> The original design open-coded the individual association code into the
> body of irq_domain_associate_many(), but with no longer needing to
> unwind associations, the code becomes simpler to split out
> irq_domain_associate() to contain the bulk of the logic, and
> irq_domain_associate_many() to be a simple loop wrapper.
>
> This patch also adds a new error check to the associate path to make
> sure it isn't called for an irq larger than the controller can handle,
> and adds locking so that the irq_domain_mutex is held while setting up a
> new association.
>
> Signed-off-by: Grant Likely <grant.likely at linaro.org>
> ---
> include/linux/irqdomain.h | 22 +++---
> kernel/irq/irqdomain.c | 185 +++++++++++++++++++++++-----------------------
> 2 files changed, 101 insertions(+), 106 deletions(-)
>
> diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
> index fd4b26f..f9e8e06 100644
> --- a/include/linux/irqdomain.h
> +++ b/include/linux/irqdomain.h
> @@ -103,6 +103,7 @@ struct irq_domain {
> struct irq_domain_chip_generic *gc;
>
> /* reverse map data. The linear map gets appended to the irq_domain */
> + irq_hw_number_t hwirq_max;
> unsigned int revmap_direct_max_irq;
> unsigned int revmap_size;
> struct radix_tree_root revmap_tree;
> @@ -110,8 +111,8 @@ struct irq_domain {
> };
>
> #ifdef CONFIG_IRQ_DOMAIN
> -struct irq_domain *__irq_domain_add(struct device_node *of_node,
> - int size, int direct_max,
> +struct irq_domain *__irq_domain_add(struct device_node *of_node, int size,
> + irq_hw_number_t hwirq_max, int direct_max,
> const struct irq_domain_ops *ops,
> void *host_data);
> struct irq_domain *irq_domain_add_simple(struct device_node *of_node,
> @@ -140,14 +141,14 @@ static inline struct irq_domain *irq_domain_add_linear(struct device_node *of_no
> const struct irq_domain_ops *ops,
> void *host_data)
> {
> - return __irq_domain_add(of_node, size, 0, ops, host_data);
> + return __irq_domain_add(of_node, size, size, 0, ops, host_data);
> }
> static inline struct irq_domain *irq_domain_add_nomap(struct device_node *of_node,
> unsigned int max_irq,
> const struct irq_domain_ops *ops,
> void *host_data)
> {
> - return __irq_domain_add(of_node, 0, max_irq, ops, host_data);
> + return __irq_domain_add(of_node, 0, max_irq, max_irq, ops, host_data);
> }
> static inline struct irq_domain *irq_domain_add_legacy_isa(
> struct device_node *of_node,
> @@ -166,14 +167,11 @@ static inline struct irq_domain *irq_domain_add_tree(struct device_node *of_node
>
> extern void irq_domain_remove(struct irq_domain *host);
>
> -extern int irq_domain_associate_many(struct irq_domain *domain,
> - unsigned int irq_base,
> - irq_hw_number_t hwirq_base, int count);
> -static inline int irq_domain_associate(struct irq_domain *domain, unsigned int irq,
> - irq_hw_number_t hwirq)
> -{
> - return irq_domain_associate_many(domain, irq, hwirq, 1);
> -}
> +extern int irq_domain_associate(struct irq_domain *domain, unsigned int irq,
> + irq_hw_number_t hwirq);
> +extern void irq_domain_associate_many(struct irq_domain *domain,
> + unsigned int irq_base,
> + irq_hw_number_t hwirq_base, int count);
>
> extern unsigned int irq_create_mapping(struct irq_domain *host,
> irq_hw_number_t hwirq);
> diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
> index 280b804..80e9249 100644
> --- a/kernel/irq/irqdomain.c
> +++ b/kernel/irq/irqdomain.c
> @@ -35,8 +35,8 @@ static struct irq_domain *irq_default_domain;
> * register allocated irq_domain with irq_domain_register(). Returns pointer
> * to IRQ domain, or NULL on failure.
> */
> -struct irq_domain *__irq_domain_add(struct device_node *of_node,
> - int size, int direct_max,
> +struct irq_domain *__irq_domain_add(struct device_node *of_node, int size,
> + irq_hw_number_t hwirq_max, int direct_max,
> const struct irq_domain_ops *ops,
> void *host_data)
> {
> @@ -52,6 +52,7 @@ struct irq_domain *__irq_domain_add(struct device_node *of_node,
> domain->ops = ops;
> domain->host_data = host_data;
> domain->of_node = of_node_get(of_node);
> + domain->hwirq_max = hwirq_max;
> domain->revmap_size = size;
> domain->revmap_direct_max_irq = direct_max;
>
> @@ -126,7 +127,7 @@ struct irq_domain *irq_domain_add_simple(struct device_node *of_node,
> {
> struct irq_domain *domain;
>
> - domain = __irq_domain_add(of_node, size, 0, ops, host_data);
> + domain = __irq_domain_add(of_node, size, size, 0, ops, host_data);
> if (!domain)
> return NULL;
>
> @@ -139,7 +140,7 @@ struct irq_domain *irq_domain_add_simple(struct device_node *of_node,
> pr_info("Cannot allocate irq_descs @ IRQ%d, assuming pre-allocated\n",
> first_irq);
> }
> - WARN_ON(irq_domain_associate_many(domain, first_irq, 0, size));
> + irq_domain_associate_many(domain, first_irq, 0, size);
> }
>
> return domain;
> @@ -170,11 +171,12 @@ struct irq_domain *irq_domain_add_legacy(struct device_node *of_node,
> {
> struct irq_domain *domain;
>
> - domain = __irq_domain_add(of_node, first_hwirq + size, 0, ops, host_data);
> + domain = __irq_domain_add(of_node, first_hwirq + size,
> + first_hwirq + size, 0, ops, host_data);
> if (!domain)
> return NULL;
>
> - WARN_ON(irq_domain_associate_many(domain, first_irq, first_hwirq, size));
> + irq_domain_associate_many(domain, first_irq, first_hwirq, size);
>
> return domain;
> }
> @@ -228,109 +230,109 @@ void irq_set_default_host(struct irq_domain *domain)
> }
> EXPORT_SYMBOL_GPL(irq_set_default_host);
>
> -static void irq_domain_disassociate_many(struct irq_domain *domain,
> - unsigned int irq_base, int count)
> +static void irq_domain_disassociate(struct irq_domain *domain, unsigned int irq)
> {
> - /*
> - * disassociate in reverse order;
> - * not strictly necessary, but nice for unwinding
> - */
> - while (count--) {
> - int irq = irq_base + count;
> - struct irq_data *irq_data = irq_get_irq_data(irq);
> - irq_hw_number_t hwirq;
> + struct irq_data *irq_data = irq_get_irq_data(irq);
> + irq_hw_number_t hwirq;
>
> - if (WARN_ON(!irq_data || irq_data->domain != domain))
> - continue;
> + if (WARN(!irq_data || irq_data->domain != domain,
> + "virq%i doesn't exist; cannot disassociate\n", irq))
> + return;
>
> - hwirq = irq_data->hwirq;
> - irq_set_status_flags(irq, IRQ_NOREQUEST);
> + hwirq = irq_data->hwirq;
> + irq_set_status_flags(irq, IRQ_NOREQUEST);
>
> - /* remove chip and handler */
> - irq_set_chip_and_handler(irq, NULL, NULL);
> + /* remove chip and handler */
> + irq_set_chip_and_handler(irq, NULL, NULL);
>
> - /* Make sure it's completed */
> - synchronize_irq(irq);
> + /* Make sure it's completed */
> + synchronize_irq(irq);
>
> - /* Tell the PIC about it */
> - if (domain->ops->unmap)
> - domain->ops->unmap(domain, irq);
> - smp_mb();
> + /* Tell the PIC about it */
> + if (domain->ops->unmap)
> + domain->ops->unmap(domain, irq);
> + smp_mb();
>
> - irq_data->domain = NULL;
> - irq_data->hwirq = 0;
> + irq_data->domain = NULL;
> + irq_data->hwirq = 0;
>
> - /* Clear reverse map for this hwirq */
> - if (hwirq < domain->revmap_size) {
> - domain->linear_revmap[hwirq] = 0;
> - } else {
> - mutex_lock(&revmap_trees_mutex);
> - radix_tree_delete(&domain->revmap_tree, hwirq);
> - mutex_unlock(&revmap_trees_mutex);
> - }
> + /* Clear reverse map for this hwirq */
> + if (hwirq < domain->revmap_size) {
> + domain->linear_revmap[hwirq] = 0;
> + } else {
> + mutex_lock(&revmap_trees_mutex);
> + radix_tree_delete(&domain->revmap_tree, hwirq);
> + mutex_unlock(&revmap_trees_mutex);
> }
> }
>
> -int irq_domain_associate_many(struct irq_domain *domain, unsigned int irq_base,
> - irq_hw_number_t hwirq_base, int count)
> +int irq_domain_associate(struct irq_domain *domain, unsigned int virq,
> + irq_hw_number_t hwirq)
> {
> - unsigned int virq = irq_base;
> - irq_hw_number_t hwirq = hwirq_base;
> - int i, ret;
> + struct irq_data *irq_data = irq_get_irq_data(virq);
> + int ret;
>
> - pr_debug("%s(%s, irqbase=%i, hwbase=%i, count=%i)\n", __func__,
> - of_node_full_name(domain->of_node), irq_base, (int)hwirq_base, count);
> + if (WARN(hwirq >= domain->hwirq_max,
> + "error: hwirq 0x%x is too large for %s\n", (int)hwirq, domain->name))
> + return -EINVAL;
> + if (WARN(!irq_data, "error: virq%i is not allocated", virq))
> + return -EINVAL;
> + if (WARN(irq_data->domain, "error: virq%i is already associated", virq))
> + return -EINVAL;
Hi Grant,
I have a qestion here, assume that we have three hwirqs and alloc three
virqs, for first irq, it check irq_data
and irq_data->domain pass, but the second is failed, then this code do
nothing with failed( in
irq_domain_associate_many()) and continue to associated the third one.
This should be very dangours, even though I have no idea of when this
could happen.
Thanks
Mike
> - for (i = 0; i < count; i++) {
> - struct irq_data *irq_data = irq_get_irq_data(virq + i);
> -
> - if (WARN(!irq_data, "error: irq_desc not allocated; "
> - "irq=%i hwirq=0x%x\n", virq + i, (int)hwirq + i))
> - return -EINVAL;
> - if (WARN(irq_data->domain, "error: irq_desc already associated; "
> - "irq=%i hwirq=0x%x\n", virq + i, (int)hwirq + i))
> - return -EINVAL;
> - };
> -
> - for (i = 0; i < count; i++, virq++, hwirq++) {
> - struct irq_data *irq_data = irq_get_irq_data(virq);
> -
> - irq_data->hwirq = hwirq;
> - irq_data->domain = domain;
> - if (domain->ops->map) {
> - ret = domain->ops->map(domain, virq, hwirq);
> - if (ret != 0) {
> - /*
> - * If map() returns -EPERM, this interrupt is protected
> - * by the firmware or some other service and shall not
> - * be mapped. Don't bother telling the user about it.
> - */
> - if (ret != -EPERM) {
> - pr_info("%s didn't like hwirq-0x%lx to VIRQ%i mapping (rc=%d)\n",
> - domain->name, hwirq, virq, ret);
> - }
> - irq_data->domain = NULL;
> - irq_data->hwirq = 0;
> - continue;
> + mutex_lock(&irq_domain_mutex);
> + irq_data->hwirq = hwirq;
> + irq_data->domain = domain;
> + if (domain->ops->map) {
> + ret = domain->ops->map(domain, virq, hwirq);
> + if (ret != 0) {
> + /*
> + * If map() returns -EPERM, this interrupt is protected
> + * by the firmware or some other service and shall not
> + * be mapped. Don't bother telling the user about it.
> + */
> + if (ret != -EPERM) {
> + pr_info("%s didn't like hwirq-0x%lx to VIRQ%i mapping (rc=%d)\n",
> + domain->name, hwirq, virq, ret);
> }
> - /* If not already assigned, give the domain the chip's name */
> - if (!domain->name && irq_data->chip)
> - domain->name = irq_data->chip->name;
> + irq_data->domain = NULL;
> + irq_data->hwirq = 0;
> + mutex_unlock(&irq_domain_mutex);
> + return ret;
> }
>
> - if (hwirq < domain->revmap_size) {
> - domain->linear_revmap[hwirq] = virq;
> - } else {
> - mutex_lock(&revmap_trees_mutex);
> - radix_tree_insert(&domain->revmap_tree, hwirq, irq_data);
> - mutex_unlock(&revmap_trees_mutex);
> - }
> + /* If not already assigned, give the domain the chip's name */
> + if (!domain->name && irq_data->chip)
> + domain->name = irq_data->chip->name;
> + }
>
> - irq_clear_status_flags(virq, IRQ_NOREQUEST);
> + if (hwirq < domain->revmap_size) {
> + domain->linear_revmap[hwirq] = virq;
> + } else {
> + mutex_lock(&revmap_trees_mutex);
> + radix_tree_insert(&domain->revmap_tree, hwirq, irq_data);
> + mutex_unlock(&revmap_trees_mutex);
> }
> + mutex_unlock(&irq_domain_mutex);
> +
> + irq_clear_status_flags(virq, IRQ_NOREQUEST);
>
> return 0;
> }
> +EXPORT_SYMBOL_GPL(irq_domain_associate);
> +
> +void irq_domain_associate_many(struct irq_domain *domain, unsigned int irq_base,
> + irq_hw_number_t hwirq_base, int count)
> +{
> + int i;
> +
> + pr_debug("%s(%s, irqbase=%i, hwbase=%i, count=%i)\n", __func__,
> + of_node_full_name(domain->of_node), irq_base, (int)hwirq_base, count);
> +
> + for (i = 0; i < count; i++) {
> + irq_domain_associate(domain, irq_base + i, hwirq_base + i);
> + }
> +}
> EXPORT_SYMBOL_GPL(irq_domain_associate_many);
>
> /**
> @@ -460,12 +462,7 @@ int irq_create_strict_mappings(struct irq_domain *domain, unsigned int irq_base,
> if (unlikely(ret < 0))
> return ret;
>
> - ret = irq_domain_associate_many(domain, irq_base, hwirq_base, count);
> - if (unlikely(ret < 0)) {
> - irq_free_descs(irq_base, count);
> - return ret;
> - }
> -
> + irq_domain_associate_many(domain, irq_base, hwirq_base, count);
> return 0;
> }
> EXPORT_SYMBOL_GPL(irq_create_strict_mappings);
> @@ -535,7 +532,7 @@ void irq_dispose_mapping(unsigned int virq)
> if (WARN_ON(domain == NULL))
> return;
>
> - irq_domain_disassociate_many(domain, virq, 1);
> + irq_domain_disassociate(domain, virq);
> irq_free_desc(virq);
> }
> EXPORT_SYMBOL_GPL(irq_dispose_mapping);
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