[RFC Part2 v1 01/21] irqdomain: Introduce new interfaces to support hierarchy irqdomains

Yasuaki Ishimatsu
2014-09-24T06:55:29Z

(2014/09/11 23:03), Jiang Liu wrote:
> We plan to use hierarchy irqdomain to suppport CPU vector assignment,
> interrupt remapping controller, IO-APIC controller, MSI interrupt
> and hypertransport interrupt etc on x86 platforms. So extend irqdomain
> interfaces to support hierarchy irqdomain.
>
> There are already many clients of current irqdomain interfaces.
> To minimize the changes, we choose to introduce new version 2 interfaces
> to support hierarchy instead of extending existing irqdomain interfaces.
>
> According to Thomas's suggestion, the most important design decision is
> to build hierarchy struct irq_data to support hierarchy irqdomain, so
> hierarchy irqdomain related data could be saved in struct irq_data.
> With support of hierarchy irq_data, we could also support stacked
> irq_chips. This is most useful in case of set_affinity().
>
> The new hierarchy irqdomain introduces following interfaces:
> 1) irq_domain_alloc_irqs()/irq_domain_free_irqs(): allocate/release IRQ
> and related resources.
> 2) __irq_domain_alloc_irqs(): a special version to support legacy IRQs.
> 3) irq_domain_activate_irq()/irq_domain_deactivate_irq(): program
> interrupt controllers to activate/deactivate interrupt.
>
> There are also several help functions to ease irqdomain implemenations:
> 1) irq_domain_get_irq_data(): get irq_data associated with a specific
> irqdomain.
> 2) irq_domain_set_hwirq_and_chip(): save irqdomain specific data into
> irq_data.
> 3) irq_domain_alloc_irqs_parent()/irq_domain_free_irqs_parent(): invoke
> parent irqdomain's alloc/free callbacks.
>
> We also changed irq_startup()/irq_shutdown() to invoke
> irq_domain_activate_irq()/irq_domain_deactivate_irq() to program
> interrupt controller when start/stop interrupts.
>
> Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
> ---
> include/linux/irq.h | 3 +
> include/linux/irqdomain.h | 60 ++++++++
> kernel/irq/Kconfig | 3 +
> kernel/irq/chip.c | 3 +
> kernel/irq/irqdomain.c | 349 +++++++++++++++++++++++++++++++++++++++++++--
> 5 files changed, 404 insertions(+), 14 deletions(-)
>
> diff --git a/include/linux/irq.h b/include/linux/irq.h
> index 62af59242ddc..4b74565690ce 100644
> --- a/include/linux/irq.h
> +++ b/include/linux/irq.h
> @@ -151,6 +151,9 @@ struct irq_data {
> unsigned int state_use_accessors;
> struct irq_chip *chip;
> struct irq_domain *domain;
> +#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
> + struct irq_data *parent_data;
> +#endif
> void *handler_data;
> void *chip_data;
> struct msi_desc *msi_desc;
> diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
> index b0f9d16e48f6..a9ddc8534c63 100644
> --- a/include/linux/irqdomain.h
> +++ b/include/linux/irqdomain.h
> @@ -38,6 +38,7 @@
> struct device_node;
> struct irq_domain;
> struct of_device_id;
> +struct irq_chip;
>
> /* Number of irqs reserved for a legacy isa controller */
> #define NUM_ISA_INTERRUPTS 16
> @@ -64,6 +65,16 @@ struct irq_domain_ops {
> int (*xlate)(struct irq_domain *d, struct device_node *node,
> const u32 *intspec, unsigned int intsize,
> unsigned long *out_hwirq, unsigned int *out_type);
> +
> +#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
> + /* extended V2 interfaces to support hierarchy irqdomains */
> + int (*alloc)(struct irq_domain *d, unsigned int virq,
> + unsigned int nr_irqs, void *arg);
> + void (*free)(struct irq_domain *d, unsigned int virq,
> + unsigned int nr_irqs);
> + int (*activate)(struct irq_domain *d, struct irq_data *irq_data);
> + int (*deactivate)(struct irq_domain *d, struct irq_data *irq_data);
> +#endif
> };
>
> extern struct irq_domain_ops irq_generic_chip_ops;
> @@ -101,6 +112,9 @@ struct irq_domain {
> /* Optional data */
> struct device_node *of_node;
> struct irq_domain_chip_generic *gc;
> +#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
> + struct irq_domain *parent;
> +#endif
>
> /* reverse map data. The linear map gets appended to the irq_domain */
> irq_hw_number_t hwirq_max;
> @@ -220,8 +234,54 @@ int irq_domain_xlate_onetwocell(struct irq_domain *d, struct device_node *ctrlr,
> const u32 *intspec, unsigned int intsize,
> irq_hw_number_t *out_hwirq, unsigned int *out_type);
>
> +#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
> +/* V2 interfaces to support hierarchy IRQ domains. */
> +extern struct irq_data *irq_domain_get_irq_data(struct irq_domain *domain,
> + unsigned int virq);
> +extern int irq_domain_set_hwirq_and_chip(struct irq_domain *domain,
> + unsigned int virq,
> + irq_hw_number_t hwirq,
> + struct irq_chip *chip,
> + void *chip_data);
> +extern void irq_domain_reset_irq_data(struct irq_data *irq_data);
> +extern int __irq_domain_alloc_irqs(struct irq_domain *domain, int irq_base,
> + unsigned int nr_irqs, int node, void *arg,
> + bool realloc);
> +extern void irq_domain_free_irqs(unsigned int virq, unsigned int nr_irqs);
> +extern int irq_domain_activate_irq(struct irq_data *irq_data);
> +extern int irq_domain_deactivate_irq(struct irq_data *irq_data);
> +
> +static inline int irq_domain_alloc_irqs(struct irq_domain *domain, int irq_base,
> + unsigned int nr_irqs, int node, void *arg)
> +{
> + return __irq_domain_alloc_irqs(domain, irq_base, nr_irqs, node,
> + arg, false);
> +}
> +
> +static inline int irq_domain_alloc_irqs_parent(struct irq_domain *domain,
> + int irq_base, unsigned int nr_irqs, void *arg)
> +{
> + if (domain->parent && domain->parent->ops->alloc)
> + return domain->parent->ops->alloc(domain->parent, irq_base,
> + nr_irqs, arg);
> + return -ENOSYS;
> +}
> +
> +static inline void irq_domain_free_irqs_parent(struct irq_domain *domain,
> + int irq_base, unsigned int nr_irqs)
> +{
> + if (domain->parent && domain->parent->ops->free)
> + domain->parent->ops->free(domain->parent, irq_base, nr_irqs);
> +}
> +#else /* CONFIG_IRQ_DOMAIN_HIERARCHY */
> +static inline int irq_domain_activate_irq(struct irq_data *data) { return 0; }
> +static inline int irq_domain_deactivate_irq(struct irq_data *data) { return 0; }
> +#endif /* CONFIG_IRQ_DOMAIN_HIERARCHY */
> +
> #else /* CONFIG_IRQ_DOMAIN */
> static inline void irq_dispose_mapping(unsigned int virq) { }
> +static inline int irq_domain_activate_irq(struct irq_data *data) { return 0; }
> +static inline int irq_domain_deactivate_irq(struct irq_data *data) { return 0; }
> #endif /* !CONFIG_IRQ_DOMAIN */
>
> #endif /* _LINUX_IRQDOMAIN_H */
> diff --git a/kernel/irq/Kconfig b/kernel/irq/Kconfig
> index d269cecdfbf0..dc1f3d08892e 100644
> --- a/kernel/irq/Kconfig
> +++ b/kernel/irq/Kconfig
> @@ -55,6 +55,9 @@ config GENERIC_IRQ_CHIP
> config IRQ_DOMAIN
> bool
>
> +config IRQ_DOMAIN_HIERARCHY
> + bool
> +
> config IRQ_DOMAIN_DEBUG
> bool "Expose hardware/virtual IRQ mapping via debugfs"
> depends on IRQ_DOMAIN && DEBUG_FS
> diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
> index 6223fab9a9d2..46bd5e2190c3 100644
> --- a/kernel/irq/chip.c
> +++ b/kernel/irq/chip.c
> @@ -15,6 +15,7 @@
> #include <linux/module.h>
> #include <linux/interrupt.h>
> #include <linux/kernel_stat.h>
> +#include <linux/irqdomain.h>
>
> #include <trace/events/irq.h>
>
> @@ -178,6 +179,7 @@ int irq_startup(struct irq_desc *desc, bool resend)
> irq_state_clr_disabled(desc);
> desc->depth = 0;
>
> + irq_domain_activate_irq(&desc->irq_data);
> if (desc->irq_data.chip->irq_startup) {
> ret = desc->irq_data.chip->irq_startup(&desc->irq_data);
> irq_state_clr_masked(desc);
> @@ -199,6 +201,7 @@ void irq_shutdown(struct irq_desc *desc)
> desc->irq_data.chip->irq_disable(&desc->irq_data);
> else
> desc->irq_data.chip->irq_mask(&desc->irq_data);
> + irq_domain_deactivate_irq(&desc->irq_data);
> irq_state_set_masked(desc);
> }
>
> diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
> index 6534ff6ce02e..e285f3abc595 100644
> --- a/kernel/irq/irqdomain.c
> +++ b/kernel/irq/irqdomain.c
> @@ -23,6 +23,9 @@ static DEFINE_MUTEX(irq_domain_mutex);
> static DEFINE_MUTEX(revmap_trees_mutex);
> static struct irq_domain *irq_default_domain;
>
> +static int irq_domain_alloc_descs(int virq, unsigned int nr_irqs,
> + irq_hw_number_t hwirq, int node);
> +
> /**
> * __irq_domain_add() - Allocate a new irq_domain data structure
> * @of_node: optional device-tree node of the interrupt controller
> @@ -30,7 +33,7 @@ static struct irq_domain *irq_default_domain;
> * @hwirq_max: Maximum number of interrupts supported by controller
> * @direct_max: Maximum value of direct maps; Use ~0 for no limit; 0 for no
> * direct mapping
> - * @ops: map/unmap domain callbacks
> + * @ops: domain callbacks
> * @host_data: Controller private data pointer
> *
> * Allocates and initialize and irq_domain structure.
> @@ -109,7 +112,7 @@ EXPORT_SYMBOL_GPL(irq_domain_remove);
> * @first_irq: first number of irq block assigned to the domain,
> * pass zero to assign irqs on-the-fly. If first_irq is non-zero, then
> * pre-map all of the irqs in the domain to virqs starting at first_irq.
> - * @ops: map/unmap domain callbacks
> + * @ops: domain callbacks
> * @host_data: Controller private data pointer
> *
> * Allocates an irq_domain, and optionally if first_irq is positive then also
> @@ -174,10 +177,8 @@ struct irq_domain *irq_domain_add_legacy(struct device_node *of_node,
>
> domain = __irq_domain_add(of_node, first_hwirq + size,
> first_hwirq + size, 0, ops, host_data);
> - if (!domain)
> - return NULL;
> -
> - irq_domain_associate_many(domain, first_irq, first_hwirq, size);
> + if (domain)
> + irq_domain_associate_many(domain, first_irq, first_hwirq, size);
>
> return domain;
> }
> @@ -388,7 +389,6 @@ EXPORT_SYMBOL_GPL(irq_create_direct_mapping);
> unsigned int irq_create_mapping(struct irq_domain *domain,
> irq_hw_number_t hwirq)
> {
> - unsigned int hint;
> int virq;
>
> pr_debug("irq_create_mapping(0x%p, 0x%lx)\n", domain, hwirq);
> @@ -410,12 +410,8 @@ unsigned int irq_create_mapping(struct irq_domain *domain,
> }
>
> /* Allocate a virtual interrupt number */
> - hint = hwirq % nr_irqs;
> - if (hint == 0)
> - hint++;
> - virq = irq_alloc_desc_from(hint, of_node_to_nid(domain->of_node));
> - if (virq <= 0)
> - virq = irq_alloc_desc_from(1, of_node_to_nid(domain->of_node));
> + virq = irq_domain_alloc_descs(-1, 1, hwirq,
> + of_node_to_nid(domain->of_node));
> if (virq <= 0) {
> pr_debug("-> virq allocation failed\n");
> return 0;
> @@ -490,7 +486,13 @@ unsigned int irq_create_of_mapping(struct of_phandle_args *irq_data)
> }
>
> /* Create mapping */
> - virq = irq_create_mapping(domain, hwirq);
> +#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
> + if (domain->ops->alloc)
> + virq = irq_domain_alloc_irqs(domain, -1, 1, NUMA_NO_NODE,
> + irq_data);
> + else
> +#endif
> + virq = irq_create_mapping(domain, hwirq);
> if (!virq)
> return virq;
>
> @@ -540,7 +542,11 @@ unsigned int irq_find_mapping(struct irq_domain *domain,
> return 0;
>
> if (hwirq < domain->revmap_direct_max_irq) {
> +#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
> + data = irq_domain_get_irq_data(domain, hwirq);
> +#else
> data = irq_get_irq_data(hwirq);
> +#endif
> if (data && (data->domain == domain) && (data->hwirq == hwirq))
> return hwirq;
> }
> @@ -709,3 +715,318 @@ const struct irq_domain_ops irq_domain_simple_ops = {
> .xlate = irq_domain_xlate_onetwocell,
> };
> EXPORT_SYMBOL_GPL(irq_domain_simple_ops);
> +
> +static int irq_domain_alloc_descs(int virq, unsigned int nr_irqs,
> + irq_hw_number_t hwirq, int node)
> +{
> + unsigned int hint;
> +
> + if (virq >= 0) {
> + virq = irq_alloc_descs(virq, virq, nr_irqs, node);
> + } else {
> + hint = hwirq % nr_irqs;
> + if (hint == 0)
> + hint++;
> + virq = irq_alloc_descs_from(hint, nr_irqs, node);
> + if (virq <= 0 && hint > 1)
> + virq = irq_alloc_descs_from(1, nr_irqs, node);
> + }
> +
> + return virq;
> +}
> +
> +#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
> +static void irq_domain_free_descs(unsigned int virq, unsigned int nr_irqs)
> +{
> + unsigned int i;
> +
> + for (i = 0; i < nr_irqs; i++)
> + irq_free_desc(virq + i);
> +}
> +
> +static void irq_domain_insert_irq(int virq)
> +{
> + struct irq_data *data;
> +
> + for (data = irq_get_irq_data(virq); data; data = data->parent_data) {
> + struct irq_domain *domain = data->domain;
> + irq_hw_number_t hwirq = data->hwirq;
> +
> + if (hwirq < domain->revmap_size) {
> + domain->linear_revmap[hwirq] = virq;
> + } else {
> + mutex_lock(&revmap_trees_mutex);
> + radix_tree_insert(&domain->revmap_tree, hwirq, data);
> + mutex_unlock(&revmap_trees_mutex);
> + }
> +
> + /* If not already assigned, give the domain the chip's name */
> + if (!domain->name && data->chip)
> + domain->name = data->chip->name;
> + }
> +
> + irq_clear_status_flags(virq, IRQ_NOREQUEST);
> +}
> +
> +static void irq_domain_remove_irq(int virq)
> +{
> + struct irq_data *data;
> +
> + irq_set_status_flags(virq, IRQ_NOREQUEST);
> + irq_set_chip_and_handler(virq, NULL, NULL);
> + synchronize_irq(virq);
> + smp_mb();
> +
> + for (data = irq_get_irq_data(virq); data; data = data->parent_data) {
> + struct irq_domain *domain = data->domain;
> + irq_hw_number_t hwirq = data->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);
> + }
> + }
> +}
> +
> +static struct irq_data *irq_domain_insert_irq_data(struct irq_domain *domain,
> + struct irq_data *child)
> +{
> + struct irq_data *irq_data;
> +
> + irq_data = kzalloc_node(sizeof(*irq_data), GFP_KERNEL, child->node);
> + if (irq_data) {
> + child->parent_data = irq_data;
> + irq_data->irq = child->irq;
> + irq_data->node = child->node;
> + irq_data->domain = domain;
> + }
> +
> + return irq_data;
> +}
> +
> +static void irq_domain_free_irq_data(unsigned int virq, unsigned int nr_irqs)
> +{
> + int i;
> + struct irq_data *irq_data, *tmp;
> +
> + for (i = 0; i < nr_irqs; i++) {

> + irq_data = irq_get_irq_data(virq + i);
> + tmp = irq_data->parent_data;

Why don't you care NULL condition?

> + irq_data->parent_data = NULL;
> + irq_data->domain = NULL;
> +
> + while (tmp) {
> + irq_data = tmp;
> + tmp = tmp->parent_data;
> + kfree(irq_data);
> + }
> + }
> +}
> +
> +static int irq_domain_alloc_irq_data(struct irq_domain *domain,
> + unsigned int virq, unsigned int nr_irqs)
> +{
> + int i;
> + struct irq_data *irq_data;
> + struct irq_domain *parent;
> +
> + /* The outmost irq_data is embedded in struct irq_desc */
> + for (i = 0; i < nr_irqs; i++) {

> + irq_data = irq_get_irq_data(virq + i);
> + irq_data->domain = domain;

ditto.

Thanks,
Yasuaki Ishimatsu

> +
> + for (parent = domain->parent; parent; parent = parent->parent) {
> + irq_data = irq_domain_insert_irq_data(parent, irq_data);
> + if (!irq_data) {
> + irq_domain_free_irq_data(virq, i + 1);
> + return -ENOMEM;
> + }
> + }
> + }
> +
> + return 0;
> +}
> +
> +/**
> + * irq_domain_get_irq_data - Get irq_data assoicated with @virq and @domain
> + * @domain: domain to match
> + * @virq: IRQ number to get irq_data
> + */
> +struct irq_data *irq_domain_get_irq_data(struct irq_domain *domain,
> + unsigned int virq)
> +{
> + struct irq_data *irq_data;
> +
> + for (irq_data = irq_get_irq_data(virq); irq_data;
> + irq_data = irq_data->parent_data)
> + if (irq_data->domain == domain)
> + return irq_data;
> +
> + return NULL;
> +}
> +
> +int irq_domain_set_hwirq_and_chip(struct irq_domain *domain, unsigned int virq,
> + irq_hw_number_t hwirq, struct irq_chip *chip,
> + void *chip_data)
> +{
> + struct irq_data *irq_data = irq_domain_get_irq_data(domain, virq);
> +
> + if (!irq_data)
> + return -ENOENT;
> +
> + irq_data->hwirq = hwirq;
> + irq_data->chip = chip;
> + irq_data->chip_data = chip_data;
> +
> + return 0;
> +}
> +
> +void irq_domain_reset_irq_data(struct irq_data *irq_data)
> +{
> + irq_data->hwirq = 0;
> + irq_data->chip = NULL;
> + irq_data->chip_data = NULL;
> +}
> +
> +/**
> + * irq_domain_alloc_irqs - Allocate IRQs from domain
> + * @domain: domain to allocate from
> + * @irq_base: allocate specified IRQ nubmer if irq_base >= 0
> + * @nr_irqs: number of IRQs to allocate
> + * @node: NUMA node id for memory allocation
> + * @arg: domain specific argument
> + * @realloc: IRQ descriptors have already been allocated if true
> + *
> + * Allocate IRQ numbers and initialized all data structures to support
> + * hiearchy IRQ domains.
> + * Parameter @realloc is mainly to support legacy IRQs.
> + * Returns error code or allocated IRQ number
> + */
> +int __irq_domain_alloc_irqs(struct irq_domain *domain, int irq_base,
> + unsigned int nr_irqs, int node, void *arg,
> + bool realloc)
> +{
> + int i, ret, virq;
> +
> + if (domain == NULL) {
> + domain = irq_default_domain;
> + if (WARN(!domain, "domain is NULL; cannot allocate IRQ\n"))
> + return -EINVAL;
> + }
> +
> + if (!domain->ops->alloc) {
> + pr_debug("domain->ops->alloc() is NULL\n");
> + return -ENOSYS;
> + }
> +
> + if (realloc && irq_base >= 0) {
> + virq = irq_base;
> + } else {
> + virq = irq_domain_alloc_descs(irq_base, nr_irqs, 0, node);
> + if (virq < 0) {
> + pr_debug("cannot allocate IRQ(base %d, count %d)\n",
> + irq_base, nr_irqs);
> + return virq;
> + }
> + }
> +
> + if (irq_domain_alloc_irq_data(domain, virq, nr_irqs)) {
> + pr_debug("cannot allocate memory for IRQ%d\n", virq);
> + ret = -ENOMEM;
> + goto out_free_desc;
> + }
> +
> + mutex_lock(&irq_domain_mutex);
> + ret = domain->ops->alloc(domain, virq, nr_irqs, arg);
> + if (ret < 0) {
> + mutex_unlock(&irq_domain_mutex);
> + goto out_free_irq_data;
> + }
> + for (i = 0; i < nr_irqs; i++)
> + irq_domain_insert_irq(virq + i);
> + mutex_unlock(&irq_domain_mutex);
> +
> + return virq;
> +
> +out_free_irq_data:
> + irq_domain_free_irq_data(virq, nr_irqs);
> +out_free_desc:
> + irq_domain_free_descs(virq, nr_irqs);
> + return ret;
> +}
> +
> +/**
> + * irq_domain_free_irqs - Free IRQ number and assoicated data structures
> + * @virq: base IRQ number
> + * @nr_irqs: number of IRQs to free
> + */
> +void irq_domain_free_irqs(unsigned int virq, unsigned int nr_irqs)
> +{
> + int i;
> + struct irq_data *data = irq_get_irq_data(virq);
> +
> + if (WARN(!data || !data->domain || !data->domain->ops->free,
> + "NULL pointer, cannot free irq\n"))
> + return;
> +
> + mutex_lock(&irq_domain_mutex);
> + for (i = 0; i < nr_irqs; i++)
> + irq_domain_remove_irq(virq + i);
> + data->domain->ops->free(data->domain, virq, nr_irqs);
> + mutex_unlock(&irq_domain_mutex);
> +
> + irq_domain_free_irq_data(virq, nr_irqs);
> + irq_domain_free_descs(virq, nr_irqs);
> +}
> +
> +/**
> + * irq_domain_activate_irq - Call domain_ops->activate recursively to activate
> + * interrupt
> + * @irq_data: out most irq_data associated with interrupt
> + *
> + * It calls domain_ops->activate to program interrupt controllers, so the
> + * interrupt could actually delivered.
> + */
> +int irq_domain_activate_irq(struct irq_data *irq_data)
> +{
> + int ret = 0;
> +
> + if (irq_data && irq_data->domain) {
> + struct irq_domain *domain = irq_data->domain;
> +
> + if (irq_data->parent_data)
> + ret = irq_domain_activate_irq(irq_data->parent_data);
> + if (ret == 0 && domain->ops->activate)
> + ret = domain->ops->activate(domain, irq_data);
> + }
> +
> + return ret;
> +}
> +
> +/**
> + * irq_domain_deactivate_irq - Call domain_ops->deactivate recursively to
> + * deactivate interrupt
> + * @irq_data: out most irq_data associated with interrupt
> + *
> + * It calls domain_ops->deactivate to program interrupt controllers to disable
> + * interrupt delivery.
> + */
> +int irq_domain_deactivate_irq(struct irq_data *irq_data)
> +{
> + int ret = 0;
> +
> + if (irq_data && irq_data->domain) {
> + struct irq_domain *domain = irq_data->domain;
> +
> + if (domain->ops->deactivate)
> + ret = domain->ops->deactivate(domain, irq_data);
> + if (ret == 0 && irq_data->parent_data)
> + ret = irq_domain_deactivate_irq(irq_data->parent_data);
> + }
> +
> + return ret;
> +}
> +#endif /* CONFIG_IRQ_DOMAIN_HIERARCHY */
>