Commit 5fe0c1f2 authored by Benjamin Herrenschmidt's avatar Benjamin Herrenschmidt
Browse files

irqdomain: Allow quiet failure mode 



Some interrupt controllers refuse to map interrupts marked as
"protected" by firwmare. Since we try to map everyting in the
device-tree on some platforms, we end up with a lot of nasty
WARN's in the boot log for what is a normal situation on those
machines.

This defines a specific return code (-EPERM) from the host map()
callback which cause irqdomain to fail silently.

MPIC is updated to return this when hitting a protected source
printing only a single line message for diagnostic purposes.

Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent f3d40c25

arch/powerpc/sysdev/mpic.c

+11 −3
Original line number Diff line number Diff line
@@ -1001,8 +1001,12 @@ static int mpic_host_map(struct irq_domain *h, unsigned int virq, 


	if (hw == mpic->spurious_vec)

		return -EINVAL;

	if (mpic->protected && test_bit(hw, mpic->protected))

		return -EINVAL;

	if (mpic->protected && test_bit(hw, mpic->protected)) {

		pr_warning("mpic: Mapping of source 0x%x failed, "

			   "source protected by firmware !\n",\

			   (unsigned int)hw);

		return -EPERM;

	}



#ifdef CONFIG_SMP

	else if (hw >= mpic->ipi_vecs[0]) {
@@ -1029,8 +1033,12 @@ static int mpic_host_map(struct irq_domain *h, unsigned int virq, 
	if (mpic_map_error_int(mpic, virq, hw))

		return 0;



	if (hw >= mpic->num_sources)

	if (hw >= mpic->num_sources) {

		pr_warning("mpic: Mapping of source 0x%x failed, "

			   "source out of range !\n",\

			   (unsigned int)hw);

		return -EINVAL;

	}



	mpic_msi_reserve_hwirq(mpic, hw);

kernel/irq/irqdomain.c

+17 −3
Original line number Diff line number Diff line
@@ -462,9 +462,23 @@ int irq_domain_associate_many(struct irq_domain *domain, unsigned int irq_base, 
		if (domain->ops->map) {

			ret = domain->ops->map(domain, virq, hwirq);

			if (ret != 0) {

				/*

				 * If map() returns -EPERM, this interrupt is protected

				 * by the firmware or some other service and shall not

				 * be mapped.

				 *

				 * Since on some platforms we blindly try to map everything

				 * we end up with a log full of backtraces.

				 *

				 * So instead, we silently fail on -EPERM, it is the

				 * responsibility of the PIC driver to display a relevant

				 * message if needed.

				 */

				if (ret != -EPERM) {

					pr_err("irq-%i==>hwirq-0x%lx mapping failed: %d\n",

					       virq, hwirq, ret);

					WARN_ON(1);

				}

				irq_data->domain = NULL;

				irq_data->hwirq = 0;

				goto err_unmap;

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