diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2024-01-27 21:47:39 +0530 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2024-02-15 17:55:41 +0100 |
| commit | 0ee1578b00bcf5ef8e7955f0c6f02a624443eb29 (patch) | |
| tree | a4f3fd5140f1fba22976da2a6c8e7f20189c5116 /include/linux/irqdomain.h | |
| parent | 9d1c58c8004653b37721dd7b16f4360216778c94 (diff) | |
genirq/msi: Provide allocation/free functions for "wired" MSI interrupts
To support wire to MSI bridges proper in the MSI core infrastructure it is
required to have separate allocation/free interfaces which can be invoked
from the regular irqdomain allocaton/free functions.
The mechanism for allocation is:
- Allocate the next free MSI descriptor index in the domain
- Store the hardware interrupt number and the trigger type
which was extracted by the irqdomain core from the firmware spec
in the MSI descriptor device cookie so it can be retrieved by
the underlying interrupt domain and interrupt chip
- Use the regular MSI allocation mechanism for the newly allocated
index which returns a fully initialized Linux interrupt on succes
This works because:
- the domains have a fixed size
- each hardware interrupt is only allocated once
- the underlying domain does not care about the MSI index it only cares
about the hardware interrupt number and the trigger type
The free function looks up the MSI index in the MSI descriptor of the
provided Linux interrupt number and uses the regular index based free
functions of the MSI core.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240127161753.114685-12-apatel@ventanamicro.com
Diffstat (limited to 'include/linux/irqdomain.h')
| -rw-r--r-- | include/linux/irqdomain.h | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h index ee0a82c60508..21ecf582a0fe 100644 --- a/include/linux/irqdomain.h +++ b/include/linux/irqdomain.h @@ -619,6 +619,23 @@ static inline bool irq_domain_is_msi_device(struct irq_domain *domain) #endif /* CONFIG_IRQ_DOMAIN_HIERARCHY */ +#ifdef CONFIG_GENERIC_MSI_IRQ +int msi_device_domain_alloc_wired(struct irq_domain *domain, unsigned int hwirq, + unsigned int type); +void msi_device_domain_free_wired(struct irq_domain *domain, unsigned int virq); +#else +static inline int msi_device_domain_alloc_wired(struct irq_domain *domain, unsigned int hwirq, + unsigned int type) +{ + WARN_ON_ONCE(1); + return -EINVAL; +} +static inline void msi_device_domain_free_wired(struct irq_domain *domain, unsigned int virq) +{ + WARN_ON_ONCE(1); +} +#endif + #else /* CONFIG_IRQ_DOMAIN */ static inline void irq_dispose_mapping(unsigned int virq) { } static inline struct irq_domain *irq_find_matching_fwnode( |