powerpc/xive: Fix bogus error code returned by OPAL

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@bahia.lan
This commit is contained in:
Greg Kurz
2019-09-11 17:52:18 +02:00
committed by Michael Ellerman
parent 92c94dfb69
commit 6ccb4ac2bf
3 changed files with 13 additions and 2 deletions

View File

@@ -272,7 +272,7 @@ int64_t opal_xive_get_vp_info(uint64_t vp,
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);