int register_memory_notifier(struct notifier_block *nb)
{
- return blocking_notifier_chain_register(&memory_chain, nb);
+ return blocking_notifier_chain_register(&memory_chain, nb);
}
EXPORT_SYMBOL(register_memory_notifier);
void unregister_memory_notifier(struct notifier_block *nb)
{
- blocking_notifier_chain_unregister(&memory_chain, nb);
+ blocking_notifier_chain_unregister(&memory_chain, nb);
}
EXPORT_SYMBOL(unregister_memory_notifier);
* so that they're not open-coded
*/
switch (mem->state) {
- case MEM_ONLINE:
- len = sprintf(buf, "online\n");
- break;
- case MEM_OFFLINE:
- len = sprintf(buf, "offline\n");
- break;
- case MEM_GOING_OFFLINE:
- len = sprintf(buf, "going-offline\n");
- break;
- default:
- len = sprintf(buf, "ERROR-UNKNOWN-%ld\n",
- mem->state);
- WARN_ON(1);
- break;
+ case MEM_ONLINE:
+ len = sprintf(buf, "online\n");
+ break;
+ case MEM_OFFLINE:
+ len = sprintf(buf, "offline\n");
+ break;
+ case MEM_GOING_OFFLINE:
+ len = sprintf(buf, "going-offline\n");
+ break;
+ default:
+ len = sprintf(buf, "ERROR-UNKNOWN-%ld\n",
+ mem->state);
+ WARN_ON(1);
+ break;
}
return len;
/*
* MEMORY_HOTPLUG depends on SPARSEMEM in mm/Kconfig, so it is
* OK to have direct references to sparsemem variables in here.
+ * Must already be protected by mem_hotplug_begin().
*/
static int
memory_block_action(unsigned long phys_index, unsigned long action, int online_type)
struct page *first_page;
int ret;
- start_pfn = phys_index << PFN_SECTION_SHIFT;
+ start_pfn = section_nr_to_pfn(phys_index);
first_page = pfn_to_page(start_pfn);
switch (action) {
- case MEM_ONLINE:
- if (!pages_correctly_reserved(start_pfn))
- return -EBUSY;
-
- ret = online_pages(start_pfn, nr_pages, online_type);
- break;
- case MEM_OFFLINE:
- ret = offline_pages(start_pfn, nr_pages);
- break;
- default:
- WARN(1, KERN_WARNING "%s(%ld, %ld) unknown action: "
- "%ld\n", __func__, phys_index, action, action);
- ret = -EINVAL;
+ case MEM_ONLINE:
+ if (!pages_correctly_reserved(start_pfn))
+ return -EBUSY;
+
+ ret = online_pages(start_pfn, nr_pages, online_type);
+ break;
+ case MEM_OFFLINE:
+ ret = offline_pages(start_pfn, nr_pages);
+ break;
+ default:
+ WARN(1, KERN_WARNING "%s(%ld, %ld) unknown action: "
+ "%ld\n", __func__, phys_index, action, action);
+ ret = -EINVAL;
}
return ret;
if (mem->online_type < 0)
mem->online_type = MMOP_ONLINE_KEEP;
+ /* Already under protection of mem_hotplug_begin() */
ret = memory_block_change_state(mem, MEM_ONLINE, MEM_OFFLINE);
/* clear online_type */
goto err;
}
+ /*
+ * Memory hotplug needs to hold mem_hotplug_begin() for probe to find
+ * the correct memory block to online before doing device_online(dev),
+ * which will take dev->mutex. Take the lock early to prevent an
+ * inversion, memory_subsys_online() callbacks will be implemented by
+ * assuming it's already protected.
+ */
+ mem_hotplug_begin();
+
switch (online_type) {
case MMOP_ONLINE_KERNEL:
case MMOP_ONLINE_MOVABLE:
case MMOP_ONLINE_KEEP:
- /*
- * mem->online_type is not protected so there can be a
- * race here. However, when racing online, the first
- * will succeed and the second will just return as the
- * block will already be online. The online type
- * could be either one, but that is expected.
- */
mem->online_type = online_type;
ret = device_online(&mem->dev);
break;
ret = -EINVAL; /* should never happen */
}
+ mem_hotplug_done();
err:
unlock_device_hotplug();