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Diffstat (limited to 'drivers/base/memory.c')
-rw-r--r--drivers/base/memory.c21
1 files changed, 13 insertions, 8 deletions
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index af9c911cd6b5..2804aed3f416 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -219,6 +219,7 @@ static bool pages_correctly_reserved(unsigned long start_pfn)
/*
* 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)
@@ -228,7 +229,7 @@ memory_block_action(unsigned long phys_index, unsigned long action, int online_t
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) {
@@ -286,6 +287,7 @@ static int memory_subsys_online(struct device *dev)
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 */
@@ -328,17 +330,19 @@ store_mem_state(struct device *dev,
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;
@@ -349,6 +353,7 @@ store_mem_state(struct device *dev,
ret = -EINVAL; /* should never happen */
}
+ mem_hotplug_done();
err:
unlock_device_hotplug();