From: Thomas Gleixner <t...@linutronix.de> On x86 the allocation of irq descriptors may allocate interrupts which are in the range of the GSI interrupts. That's wrong as those interrupts are hardwired and we don't have the irq domain translation like PPC. So one of these interrupts can be hooked up later to one of the devices which are hard wired to it and the io_apic init code for that particular interrupt line happily reuses that descriptor with a completely different configuration so hell breaks lose.
Inside x86 we allocate dynamic interrupts from above nr_gsi_irqs, except for a few usage sites which have not yet blown up in our face for whatever reason. But for drivers which need an irq range, like the GPIO drivers, we have no limit in place and we don't want to expose such a detail to a driver. To cure this introduce a function which an architecture can implement to impose a lower bound on the dynamic interrupt allocations. Implement it for x86 and set the lower bound to nr_gsi_irqs, which is the end of the hardwired interrupt space, so all dynamic allocations happen above. That not only allows the GPIO driver to work sanely, it also protects the bogus callsites of create_irq_nr() in hpet, uv, irq_remapping and htirq code. They need to be cleaned up as well, but that's a separate issue. Refer to HSD4995193. Reported-by: Jin Yao <yao....@linux.intel.com> Signed-off-by: Thomas Gleixner <t...@linutronix.de> Tested-by: Mika Westerberg <mika.westerb...@linux.intel.com> Cc: Mathias Nyman <mathias.ny...@linux.intel.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Grant Likely <grant.lik...@linaro.org> Cc: H. Peter Anvin <h...@linux.intel.com> Cc: Rafael J. Wysocki <rafael.j.wyso...@intel.com> Cc: Andy Shevchenko <andriy.shevche...@linux.intel.com> Cc: Krogerus Heikki <heikki.kroge...@intel.com> Cc: Linus Walleij <linus.wall...@linaro.org> Link: http://lkml.kernel.org/r/alpine.deb.2.02.1404241617360.28...@ionos.tec.linutronix.de Signed-off-by: Thomas Gleixner <t...@linutronix.de> (cherry picked from commit 62a08ae2a5763aabeee98264605236b001503e0c) Conflicts: include/linux/irq.h kernel/softirq.c Manually edited the original patch to make it apply smoothly. Signed-off-by: Maurice Petallo <mauricex.r.peta...@intel.com> Change-Id: I7ff269d69af1546db0370bed7edf81bf8dc9ed11 Reviewed-on: https://git-gar-1.devtools.intel.com/gerrit/5707 Reviewed-by: Wan Mohamad, Wan Ahmad Zainie <wan.ahmad.zainie.wan.moha...@intel.com> Reviewed-by: Tan, Jui Nee <jui.nee....@intel.com> --- arch/x86/kernel/apic/io_apic.c | 5 +++++ include/linux/irq.h | 2 ++ kernel/irq/irqdesc.c | 7 +++++++ kernel/softirq.c | 5 +++++ 4 files changed, 19 insertions(+) diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c index 9ed796c..f5f67f9 100644 --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -3420,6 +3420,11 @@ int get_nr_irqs_gsi(void) return nr_irqs_gsi; } +unsigned int arch_dynirq_lower_bound(unsigned int from) +{ + return from < nr_irqs_gsi ? nr_irqs_gsi : from; +} + int __init arch_probe_nr_irqs(void) { int nr; diff --git a/include/linux/irq.h b/include/linux/irq.h index d591bfe..3fb6a09 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -580,6 +580,8 @@ static inline struct msi_desc *irq_data_get_msi(struct irq_data *d) return d->msi_desc; } +unsigned int arch_dynirq_lower_bound(unsigned int from); + int __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node, struct module *owner); diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c index 8ab8e93..b88dba1 100644 --- a/kernel/irq/irqdesc.c +++ b/kernel/irq/irqdesc.c @@ -363,6 +363,13 @@ __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node, if (from > irq) return -EINVAL; from = irq; + } else { + /* + * For interrupts which are freely allocated the + * architecture can force a lower bound to the @from + * argument. x86 uses this to exclude the GSI space. + */ + from = arch_dynirq_lower_bound(from); } mutex_lock(&sparse_irq_lock); diff --git a/kernel/softirq.c b/kernel/softirq.c index 787b3a0..fb54ede 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -898,3 +898,8 @@ int __init __weak arch_early_irq_init(void) return 0; } #endif + +unsigned int __weak arch_dynirq_lower_bound(unsigned int from) +{ + return from; +} -- 1.9.1 -- _______________________________________________ linux-yocto mailing list linux-yocto@yoctoproject.org https://lists.yoctoproject.org/listinfo/linux-yocto
