We eject the memory device even if it is in use. It is very dangerous,
and it will cause the kernel to be panicked.
CC: David Rientjes <rientjes@xxxxxxxxxx>
CC: Jiang Liu <liuj97@xxxxxxxxx>
CC: Len Brown <len.brown@xxxxxxxxx>
CC: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
CC: Paul Mackerras <paulus@xxxxxxxxx>
CC: Christoph Lameter <cl@xxxxxxxxx>
Cc: Minchan Kim <minchan.kim@xxxxxxxxx>
CC: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
CC: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
CC: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>
CC: Rafael J. Wysocki <rjw@xxxxxxx>
CC: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Signed-off-by: Wen Congyang <wency@xxxxxxxxxxxxxx>
---
drivers/acpi/acpi_memhotplug.c | 46 +++++++++++++++++++++++++++++++++---------
1 file changed, 36 insertions(+), 10 deletions(-)
diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
index 8914399..1fb1342 100644
--- a/drivers/acpi/acpi_memhotplug.c
+++ b/drivers/acpi/acpi_memhotplug.c
@@ -78,6 +78,7 @@ struct acpi_memory_info {
unsigned short caching; /* memory cache attribute */
unsigned short write_protect; /* memory read/write attribute */
unsigned int enabled:1;
+ unsigned int failed:1;
};
struct acpi_memory_device {
@@ -266,9 +267,23 @@ static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
node = memory_add_physaddr_to_nid(info->start_addr);
result = add_memory(node, info->start_addr, info->length);
- if (result)
+
+ /*
+ * If the memory block has been used by the kernel, add_memory()
+ * returns -EEXIST. If add_memory() returns the other error, it
+ * means that this memory block is not used by the kernel.
+ */
+ if (result && result != -EEXIST) {
+ info->failed = 1;
continue;
- info->enabled = 1;
+ }
+
+ if (!result)
+ info->enabled = 1;
+ /*
+ * Add num_enable even if add_memory() returns -EEXIST, so the
+ * device is bound to this driver.
+ */
num_enabled++;
}
mutex_unlock(&mem_device->list_lock);
@@ -324,25 +339,36 @@ static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
static int acpi_memory_remove_memory(struct acpi_memory_device *mem_device)
{
- int result;
+ int result = 0;
struct acpi_memory_info *info, *n;
mutex_lock(&mem_device->list_lock);
list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
- if (info->enabled) {
- result = remove_memory(info->start_addr, info->length);
- if (result) {
- mutex_unlock(&mem_device->list_lock);
- return result;
- }
+ if (info->failed)
+ /* The kernel does not use this memory block */
+ continue;
+
+ if (!info->enabled) {
+ /*
+ * The kernel uses this memory block, but it may be not
+ * managed by us.
+ */
+ result = -EBUSY;
+ goto out;
}
+ result = remove_memory(info->start_addr, info->length);
+ if (result)
+ goto out;
+
list_del(&info->list);
kfree(info);
}
+
+out:
mutex_unlock(&mem_device->list_lock);
- return 0;
+ return result;
}
static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
--
1.8.0
--
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