[PATCH v3 1/1] powerpc/pseries: Make RAS IRQ explicitly dependent on DLPAR WQ
From: Jose Ricardo Ziviani <hidden>
Date: 2018-01-03 21:13:09
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
The hotplug engine uses its own workqueue to handle IRQ requests, the problem is that such workqueue is initialized after init_ras_IRQ, which will cause a kernel panic if any hotplug interruption is issued in that period of time. This patch makes RAS IRQ registration explicitly dependent on DLPAR workqueue and adds a check to make sure that the workqueue is not initialized more than once. Reported-by: Min Deng <redacted> Reported-by: Daniel Henrique Barboza <redacted> Tested-by: Jose Ricardo Ziviani <redacted> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> --- arch/powerpc/platforms/pseries/dlpar.c | 21 ++++++++++++++++++--- arch/powerpc/platforms/pseries/pseries.h | 2 ++ arch/powerpc/platforms/pseries/ras.c | 3 ++- 3 files changed, 22 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/dlpar.c b/arch/powerpc/platforms/pseries/dlpar.c
index 6e35780c5962..a0b20c03f078 100644
--- a/arch/powerpc/platforms/pseries/dlpar.c
+++ b/arch/powerpc/platforms/pseries/dlpar.c@@ -574,11 +574,26 @@ static ssize_t dlpar_show(struct class *class, struct class_attribute *attr, static CLASS_ATTR_RW(dlpar); -static int __init pseries_dlpar_init(void) +int __init dlpar_workqueue_init(void) { + if (pseries_hp_wq) + return 0; + pseries_hp_wq = alloc_workqueue("pseries hotplug workqueue", - WQ_UNBOUND, 1); + WQ_UNBOUND, 1); + + return pseries_hp_wq ? 0 : -ENOMEM; +} + +static int __init dlpar_sysfs_init(void) +{ + int rc; + + rc = dlpar_workqueue_init(); + if (rc) + return rc; + return sysfs_create_file(kernel_kobj, &class_attr_dlpar.attr); } -machine_device_initcall(pseries, pseries_dlpar_init); +machine_device_initcall(pseries, dlpar_sysfs_init);
diff --git a/arch/powerpc/platforms/pseries/pseries.h b/arch/powerpc/platforms/pseries/pseries.h
index 4470a3194311..1ae1d9f4dbe9 100644
--- a/arch/powerpc/platforms/pseries/pseries.h
+++ b/arch/powerpc/platforms/pseries/pseries.h@@ -98,4 +98,6 @@ static inline unsigned long cmo_get_page_size(void) return CMO_PageSize; } +int dlpar_workqueue_init(void); + #endif /* _PSERIES_PSERIES_H */
diff --git a/arch/powerpc/platforms/pseries/ras.c b/arch/powerpc/platforms/pseries/ras.c
index 4923ffe230cf..81d8614e7379 100644
--- a/arch/powerpc/platforms/pseries/ras.c
+++ b/arch/powerpc/platforms/pseries/ras.c@@ -69,7 +69,8 @@ static int __init init_ras_IRQ(void) /* Hotplug Events */ np = of_find_node_by_path("/event-sources/hot-plug-events"); if (np != NULL) { - request_event_sources_irqs(np, ras_hotplug_interrupt, + if (dlpar_workqueue_init() == 0) + request_event_sources_irqs(np, ras_hotplug_interrupt, "RAS_HOTPLUG"); of_node_put(np); }
--
2.14.1