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 <[email protected]> CC: Jiang Liu <[email protected]> CC: Len Brown <[email protected]> CC: Benjamin Herrenschmidt <[email protected]> CC: Paul Mackerras <[email protected]> CC: Christoph Lameter <[email protected]> Cc: Minchan Kim <[email protected]> CC: Andrew Morton <[email protected]> CC: KOSAKI Motohiro <[email protected]> CC: Yasuaki Ishimatsu <[email protected]> CC: Rafael J. Wysocki <[email protected]> CC: Konrad Rzeszutek Wilk <[email protected]> Signed-off-by: Wen Congyang <[email protected]> --- drivers/acpi/acpi_memhotplug.c | 42 +++++++++++++++++++++++++++++++++--------- 1 file changed, 33 insertions(+), 9 deletions(-) diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c index e52ad5d..f7e3007 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 { @@ -257,9 +258,23 @@ 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++; } if (!num_enabled) { @@ -280,21 +295,30 @@ static int acpi_memory_enable_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; 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) - 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. + */ + return -EBUSY; + + result = remove_memory(info->start_addr, info->length); + if (result) + return result; list_del(&info->list); kfree(info); } - return 0; + return result; } static void acpi_memory_device_notify(acpi_handle handle, u32 event, void *data) -- 1.8.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
