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authorMarc Zyngier <marc.zyngier@arm.com>2016-01-26 13:52:25 +0000
committerThomas Gleixner <tglx@linutronix.de>2016-01-26 16:00:14 +0100
commit530cbe100ef7587aa5b5ac3a4b670cda4d50e598 (patch)
tree0efde6fd23cf32aa781d5791cebd92eba8be982a /kernel/irq
parent0df337cf92c107fb515c9df6907052a97bd484b9 (diff)
downloadlinux-sh-530cbe100ef7587aa5b5ac3a4b670cda4d50e598.tar.gz
irqdomain: Allow domain lookup with DOMAIN_BUS_WIRED token
Let's take the (outlandish) example of an interrupt controller capable of handling both wired interrupts and PCI MSIs. With the current code, the PCI MSI domain is going to be tagged with DOMAIN_BUS_PCI_MSI, and the wired domain with DOMAIN_BUS_ANY. Things get hairy when we start looking up the domain for a wired interrupt (typically when creating it based on some firmware information - DT or ACPI). In irq_create_fwspec_mapping(), we perform the lookup using DOMAIN_BUS_ANY, which is actually used as a wildcard. This gives us one chance out of two to end up with the wrong domain, and we try to configure a wired interrupt with the MSI domain. Everything grinds to a halt pretty quickly. What we really need to do is to start looking for a domain that would uniquely identify a wired interrupt domain, and only use DOMAIN_BUS_ANY as a fallback. In order to solve this, let's introduce a new DOMAIN_BUS_WIRED token, which is going to be used exactly as described above. Of course, this depends on the irqchip to setup the domain bus_token, and nobody had to implement this so far. Only so far. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Rob Herring <robh+dt@kernel.org> Cc: Frank Rowand <frowand.list@gmail.com> Cc: Grant Likely <grant.likely@linaro.org> Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Cc: Jiang Liu <jiang.liu@linux.intel.com> Link: http://lkml.kernel.org/r/1453816347-32720-2-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/irq')
-rw-r--r--kernel/irq/irqdomain.c11
1 files changed, 8 insertions, 3 deletions
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 8cf95de1ab3f..d75179735a28 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -575,10 +575,15 @@ unsigned int irq_create_fwspec_mapping(struct irq_fwspec *fwspec)
unsigned int type = IRQ_TYPE_NONE;
int virq;
- if (fwspec->fwnode)
- domain = irq_find_matching_fwnode(fwspec->fwnode, DOMAIN_BUS_ANY);
- else
+ if (fwspec->fwnode) {
+ domain = irq_find_matching_fwnode(fwspec->fwnode,
+ DOMAIN_BUS_WIRED);
+ if (!domain)
+ domain = irq_find_matching_fwnode(fwspec->fwnode,
+ DOMAIN_BUS_ANY);
+ } else {
domain = irq_default_domain;
+ }
if (!domain) {
pr_warn("no irq domain found for %s !\n",