There's a bug in skiboot that causes the OPAL_XIVE_ALLOCATE_IRQ call to return the 32-bit value 0xffffffff when OPAL has run out of IRQs. Unfortunatelty, OPAL return values are signed 64-bit entities and errors are supposed to be negative. If that happens, the linux code confusingly treats 0xffffffff as a valid IRQ number and panics at some point.
A fix was recently merged in skiboot: e97391ae2bb5 ("xive: fix return value of opal_xive_allocate_irq()") but we need a workaround anyway to support older skiboots already on the field. Internally convert 0xffffffff to OPAL_RESOURCE which is the usual error returned upon resource exhaustion. Signed-off-by: Greg Kurz <gr...@kaod.org> --- arch/powerpc/sysdev/xive/native.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/sysdev/xive/native.c b/arch/powerpc/sysdev/xive/native.c index 37987c815913..c35583f84f9f 100644 --- a/arch/powerpc/sysdev/xive/native.c +++ b/arch/powerpc/sysdev/xive/native.c @@ -231,6 +231,15 @@ static bool xive_native_match(struct device_node *node) return of_device_is_compatible(node, "ibm,opal-xive-vc"); } +static int64_t opal_xive_allocate_irq_fixup(uint32_t chip_id) +{ + s64 irq = opal_xive_allocate_irq(chip_id); + +#define XIVE_ALLOC_NO_SPACE 0xffffffff /* No possible space */ + return + irq == XIVE_ALLOC_NO_SPACE ? OPAL_RESOURCE : irq; +} + #ifdef CONFIG_SMP static int xive_native_get_ipi(unsigned int cpu, struct xive_cpu *xc) { @@ -238,7 +247,7 @@ static int xive_native_get_ipi(unsigned int cpu, struct xive_cpu *xc) /* Allocate an IPI and populate info about it */ for (;;) { - irq = opal_xive_allocate_irq(xc->chip_id); + irq = opal_xive_allocate_irq_fixup(xc->chip_id); if (irq == OPAL_BUSY) { msleep(OPAL_BUSY_DELAY_MS); continue; @@ -259,7 +268,7 @@ u32 xive_native_alloc_irq(void) s64 rc; for (;;) { - rc = opal_xive_allocate_irq(OPAL_XIVE_ANY_CHIP); + rc = opal_xive_allocate_irq_fixup(OPAL_XIVE_ANY_CHIP); if (rc != OPAL_BUSY) break; msleep(OPAL_BUSY_DELAY_MS);