From: Greg Kurz groug@kaod.org
commit 6ccb4ac2bf8a35c694ead92f8ac5530a16e8f2c8 upstream.
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 groug@kaod.org Reviewed-by: Cédric Le Goater clg@kaod.org Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/156821713818.1985334.14123187368108582810.stgit@ba... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/powerpc/include/asm/opal.h | 2 +- arch/powerpc/platforms/powernv/opal-call.c | 2 +- arch/powerpc/sysdev/xive/native.c | 11 +++++++++++ 3 files changed, 13 insertions(+), 2 deletions(-)
--- a/arch/powerpc/include/asm/opal.h +++ b/arch/powerpc/include/asm/opal.h @@ -272,7 +272,7 @@ int64_t opal_xive_get_vp_info(uint64_t v int64_t opal_xive_set_vp_info(uint64_t vp, uint64_t flags, uint64_t report_cl_pair); -int64_t opal_xive_allocate_irq(uint32_t chip_id); +int64_t opal_xive_allocate_irq_raw(uint32_t chip_id); int64_t opal_xive_free_irq(uint32_t girq); int64_t opal_xive_sync(uint32_t type, uint32_t id); int64_t opal_xive_dump(uint32_t type, uint32_t id); --- a/arch/powerpc/platforms/powernv/opal-call.c +++ b/arch/powerpc/platforms/powernv/opal-call.c @@ -257,7 +257,7 @@ OPAL_CALL(opal_xive_set_queue_info, OPA OPAL_CALL(opal_xive_donate_page, OPAL_XIVE_DONATE_PAGE); OPAL_CALL(opal_xive_alloc_vp_block, OPAL_XIVE_ALLOCATE_VP_BLOCK); OPAL_CALL(opal_xive_free_vp_block, OPAL_XIVE_FREE_VP_BLOCK); -OPAL_CALL(opal_xive_allocate_irq, OPAL_XIVE_ALLOCATE_IRQ); +OPAL_CALL(opal_xive_allocate_irq_raw, OPAL_XIVE_ALLOCATE_IRQ); OPAL_CALL(opal_xive_free_irq, OPAL_XIVE_FREE_IRQ); OPAL_CALL(opal_xive_get_vp_info, OPAL_XIVE_GET_VP_INFO); OPAL_CALL(opal_xive_set_vp_info, OPAL_XIVE_SET_VP_INFO); --- a/arch/powerpc/sysdev/xive/native.c +++ b/arch/powerpc/sysdev/xive/native.c @@ -231,6 +231,17 @@ static bool xive_native_match(struct dev 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) {