irqdomain: Introduce new interfaces to support hierarchy irqdomains

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.

[ tglx: Folded parts of the later patch series in ]

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Yingjoe Chen <yingjoe.chen@mediatek.com>
Cc: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 5 insertions, 0 deletions

diff --git a/include/linux/irq.h b/include/linux/irq.h
index 03f48d936f66..13ba412ce3a0 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -133,6 +133,8 @@ struct irq_domain;
  * @chip:               low level interrupt hardware access
  * @domain:             Interrupt translation domain; responsible for mapping
  *                      between hwirq number and linux irq number.
+ * @parent_data:        pointer to parent struct irq_data to support hierarchy
+ *                      irq_domain
  * @handler_data:       per-IRQ data for the irq_chip methods
  * @chip_data:          platform-specific per-chip private data for the chip
  *                      methods, to allow shared chip implementations
@@ -151,6 +153,9 @@ 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;