• Marc Zyngier's avatar
    genirq/irqdomain: Allow irq domain aliasing · ad3aedfb
    Marc Zyngier authored
    It is not uncommon (at least with the ARM stuff) to have a piece
    of hardware that implements different flavours of "interrupts".
    A typical example of this is the GICv3 ITS, which implements
    standard PCI/MSI support, but also some form of "generic MSI".
    
    So far, the PCI/MSI domain is registered using the ITS device_node,
    so that irq_find_host can return it. On the contrary, the raw MSI
    domain is not registered with an device_node, making it impossible
    to be looked up by another subsystem (obviously, using the same
    device_node twice would only result in confusion, as it is not
    defined which one irq_find_host would return).
    
    A solution to this is to "type" domains that may be aliasing, and
    to be able to lookup an device_node that matches a given type.
    For this, we introduce irq_find_matching_host() as a superset
    of irq_find_host:
    
    struct irq_domain *irq_find_matching_host(struct device_node *node,
                                    enum irq_domain_bus_token bus_token);
    
    where bus_token is the "type" we want to match the domain against
    (so far, only DOMAIN_BUS_ANY is defined). This result in some
    moderately invasive changes on the PPC side (which is the only
    user of the .match method).
    
    This has otherwise no functionnal change.
    Reviewed-by: default avatarHanjun Guo <hanjun.guo@linaro.org>
    Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
    Cc: <linux-arm-kernel@lists.infradead.org>
    Cc: Yijing Wang <wangyijing@huawei.com>
    Cc: Ma Jun <majun258@huawei.com>
    Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
    Cc: Duc Dang <dhdang@apm.com>
    Cc: Bjorn Helgaas <bhelgaas@google.com>
    Cc: Jiang Liu <jiang.liu@linux.intel.com>
    Cc: Jason Cooper <jason@lakedaemon.net>
    Link: http://lkml.kernel.org/r/1438091186-10244-2-git-send-email-marc.zyngier@arm.comSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
    ad3aedfb
interrupt.c 10.5 KB