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powerpc/pseries: Make RAS IRQ explicitly dependent on DLPAR WQ 

The hotplug code uses its own workqueue to handle IRQ requests
(pseries_hp_wq), however that workqueue is initialized after
init_ras_IRQ(). That can lead to a kernel panic if any hotplug
interrupts fire after init_ras_IRQ() but before pseries_hp_wq is
initialised. eg:

  UDP-Lite hash table entries: 2048 (order: 0, 65536 bytes)
  NET: Registered protocol family 1
  Unpacking initramfs...
  (qemu) object_add memory-backend-ram,id=mem1,size=10G
  (qemu) device_add pc-dimm,id=dimm1,memdev=mem1
  Unable to handle kernel paging request for data at address 0xf94d03007c421378
  Faulting instruction address: 0xc00000000012d744
  Oops: Kernel access of bad area, sig: 11 [#1]
  LE SMP NR_CPUS=2048 NUMA pSeries
  Modules linked in:
  CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.15.0-rc2-ziviani+ #26
  task:         (ptrval) task.stack:         (ptrval)
  NIP:  c00000000012d744 LR: c00000000012d744 CTR: 0000000000000000
  REGS:         (ptrval) TRAP: 0380   Not tainted  (4.15.0-rc2-ziviani+)
  MSR:  8000000000009033 <SF,EE,ME,IR,DR,RI,LE>  CR: 28088042  XER: 20040000
  CFAR: c00000000012d3c4 SOFTE: 0
  ...
  NIP [c00000000012d744] __queue_work+0xd4/0x5c0
  LR [c00000000012d744] __queue_work+0xd4/0x5c0
  Call Trace:
  [c0000000fffefb90] [c00000000012d744] __queue_work+0xd4/0x5c0 (unreliable)
  [c0000000fffefc70] [c00000000012dce4] queue_work_on+0xb4/0xf0

This commit makes the RAS IRQ registration explicitly dependent on the
creation of the pseries_hp_wq.

Reported-by: Min Deng <mdeng@redhat.com>
Reported-by: Daniel Henrique Barboza <danielhb@linux.vnet.ibm.com>
Tested-by: Jose Ricardo Ziviani <joserz@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
hifive-unleashed-5.1
Michael Ellerman 2018-01-08 14:54:32 +11:00
parent ecb101aed8
commit e2d5915293
3 changed files with 22 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
arch/powerpc/platforms/pseries/dlpar.c
View File

@ -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);

2
arch/powerpc/platforms/pseries/pseries.h
View File

@ -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 */

3
arch/powerpc/platforms/pseries/ras.c
View File

@ -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);
}