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authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2013-05-06 11:37:43 +1000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2013-05-06 11:37:43 +1000
commit5fe0c1f2f0dca3351536284b0180a79f341b7854 (patch)
tree20e7cc0ae006c8e21fb476d27eeed30771262706
parentf3d40c2532fee15a30d7a364ac365c21748a4a95 (diff)
downloadlinux-linaro-stable-5fe0c1f2f0dca3351536284b0180a79f341b7854.tar.gz
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: Benjamin Herrenschmidt <benh@kernel.crashing.org>
-rw-r--r--arch/powerpc/sysdev/mpic.c14
-rw-r--r--kernel/irq/irqdomain.c20
2 files changed, 28 insertions, 6 deletions
diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c
index d30e6a676c89..ee21b5e71aec 100644
--- a/arch/powerpc/sysdev/mpic.c
+++ b/arch/powerpc/sysdev/mpic.c
@@ -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);
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 96f3a1d9c379..5a83dde8ca0c 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -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) {
- pr_err("irq-%i==>hwirq-0x%lx mapping failed: %d\n",
- virq, hwirq, ret);
- WARN_ON(1);
+ /*
+ * 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;