From: Stuart Hayes stuart.w.hayes@gmail.com
[ Upstream commit 6aecee6ad41cf97c0270f72da032c10eef025bf0 ]
The dell_rbu driver takes firmware update payloads and puts them in memory so the system BIOS can find them after a reboot. This sometimes fails (though rarely), because the memory containing the payload is in the CPU cache but never gets written back to main memory before the system is rebooted (CPU cache contents are lost on reboot).
With this patch, the payload memory will be changed to uncachable to ensure that the payload is actually in main memory before the system is rebooted.
Signed-off-by: Stuart Hayes stuart.w.hayes@gmail.com Signed-off-by: Andy Shevchenko andriy.shevchenko@linux.intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/firmware/dell_rbu.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/drivers/firmware/dell_rbu.c b/drivers/firmware/dell_rbu.c index 2f452f1f7c8a0..53f27a6e2d761 100644 --- a/drivers/firmware/dell_rbu.c +++ b/drivers/firmware/dell_rbu.c @@ -45,6 +45,7 @@ #include <linux/moduleparam.h> #include <linux/firmware.h> #include <linux/dma-mapping.h> +#include <asm/set_memory.h>
MODULE_AUTHOR("Abhay Salunke abhay_salunke@dell.com"); MODULE_DESCRIPTION("Driver for updating BIOS image on DELL systems"); @@ -181,6 +182,11 @@ static int create_packet(void *data, size_t length) packet_data_temp_buf = NULL; } } + /* + * set to uncachable or it may never get written back before reboot + */ + set_memory_uc((unsigned long)packet_data_temp_buf, 1 << ordernum); + spin_lock(&rbu_data.lock);
newpacket->data = packet_data_temp_buf; @@ -349,6 +355,8 @@ static void packet_empty_list(void) * to make sure there are no stale RBU packets left in memory */ memset(newpacket->data, 0, rbu_data.packetsize); + set_memory_wb((unsigned long)newpacket->data, + 1 << newpacket->ordernum); free_pages((unsigned long) newpacket->data, newpacket->ordernum); kfree(newpacket);