At the start, OpenSBI relocates itself to its link address. If the link address ranges of U-Boot SPL and OpenSBI overlap, the relocation can lead to code corruption if a hart is still running U-Boot SPL during relocation. To avoid this problem, the main hart is specified as the preferred boot hart to perform the relocation. This fixes the code corruption problems based on the assumption that since the main hart schedules the secondary harts to enter OpenSBI, it will be the last to enter OpenSBI. However it was reported that this assumption is not always correct.
To make sure the assumption always holds true, wait for all secondary harts to acknowledge the call-function request before entering OpenSBI on the main hart.
Reported-by: Rick Chen rick@andestech.com Signed-off-by: Lukas Auer lukas.auer@aisec.fraunhofer.de Reviewed-by: Rick Chen rick@andestech.com Tested-by: Rick Chen rick@andestech.com Reviewed-by: Anup Patel anup.patel@wdc.com ---
Changes in v2: None
common/spl/spl_opensbi.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/common/spl/spl_opensbi.c b/common/spl/spl_opensbi.c index 58bf2468ce..6404373eca 100644 --- a/common/spl/spl_opensbi.c +++ b/common/spl/spl_opensbi.c @@ -76,9 +76,19 @@ void spl_invoke_opensbi(struct spl_image_info *spl_image) invalidate_icache_all();
#ifdef CONFIG_SMP + /* + * Start OpenSBI on all secondary harts and wait for acknowledgment. + * + * OpenSBI first relocates itself to its link address. This is done by + * the main hart. To make sure no hart is still running U-Boot SPL + * during relocation, we wait for all secondary harts to acknowledge + * the call-function request before entering OpenSBI on the main hart. + * Otherwise, code corruption can occur if the link address ranges of + * U-Boot SPL and OpenSBI overlap. + */ ret = smp_call_function((ulong)spl_image->entry_point, (ulong)spl_image->fdt_addr, - (ulong)&opensbi_info, 0); + (ulong)&opensbi_info, 1); if (ret) hang(); #endif