From 6ccb4ac2bf8a35c694ead92f8ac5530a16e8f2c8 Mon Sep 17 00:00:00 2001 From: Greg Kurz Date: Wed, 11 Sep 2019 17:52:18 +0200 Subject: powerpc/xive: Fix bogus error code returned by OPAL MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 in the field. Internally convert 0xffffffff to OPAL_RESOURCE which is the usual error returned upon resource exhaustion. Cc: stable@vger.kernel.org # v4.12+ Signed-off-by: Greg Kurz Reviewed-by: Cédric Le Goater Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/156821713818.1985334.14123187368108582810.stgit@bahia.lan --- arch/powerpc/sysdev/xive/native.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'arch/powerpc/sysdev') diff --git a/arch/powerpc/sysdev/xive/native.c b/arch/powerpc/sysdev/xive/native.c index 4b61e44f0171..e9481468ebd8 100644 --- a/arch/powerpc/sysdev/xive/native.c +++ b/arch/powerpc/sysdev/xive/native.c @@ -245,6 +245,17 @@ static bool xive_native_match(struct device_node *node) return of_device_is_compatible(node, "ibm,opal-xive-vc"); } +static s64 opal_xive_allocate_irq(u32 chip_id) +{ + s64 irq = opal_xive_allocate_irq_raw(chip_id); + + /* + * Old versions of skiboot can incorrectly return 0xffffffff to + * indicate no space, fix it up here. + */ + return irq == 0xffffffff ? OPAL_RESOURCE : irq; +} + #ifdef CONFIG_SMP static int xive_native_get_ipi(unsigned int cpu, struct xive_cpu *xc) { -- cgit v1.2.3