From 7a13beb213266cbf6f15ddbbef5bfca274086bd3 Mon Sep 17 00:00:00 2001 From: Anup Patel Date: Wed, 6 Nov 2019 16:24:35 +0530 Subject: firmware: Add preferred boot HART field in struct fw_dynamic_info It has been reported that link address range of previous booting stage (such as U-Boot SPL) can overlap the link address rage of FW_DYNAMIC. This means self-relocation in FW_DYNAMIC can potentially corrupt previous booting stage if any of the secondary HART enter FW_DYNAMIC before primary HART. To tackle this, we add preferred boot HART field (i.e boot_hart) in struct fw_dyanmic_info. We use this field to force secondary HARTs into relocation wait loop till preferred/primary boot HART enters FW_DYNAMIC completes self-relocation. If preferred boot HART is not available then we fall back to relocation lottery approach. Signed-off-by: Anup Patel Reviewed-by: Atish Patra --- include/sbi/fw_dynamic.h | 26 ++++++++++++++++++++++---- 1 file changed, 22 insertions(+), 4 deletions(-) (limited to 'include') diff --git a/include/sbi/fw_dynamic.h b/include/sbi/fw_dynamic.h index 695dc295..3c088311 100644 --- a/include/sbi/fw_dynamic.h +++ b/include/sbi/fw_dynamic.h @@ -18,18 +18,20 @@ #define FW_DYNAMIC_INFO_MAGIC_OFFSET (0 * __SIZEOF_POINTER__) /** Offset of version member in fw_dynamic_info */ #define FW_DYNAMIC_INFO_VERSION_OFFSET (1 * __SIZEOF_POINTER__) -/** Offset of next_addr member in fw_dynamic_info */ +/** Offset of next_addr member in fw_dynamic_info (version >= 1) */ #define FW_DYNAMIC_INFO_NEXT_ADDR_OFFSET (2 * __SIZEOF_POINTER__) -/** Offset of next_mode member in fw_dynamic_info */ +/** Offset of next_mode member in fw_dynamic_info (version >= 1) */ #define FW_DYNAMIC_INFO_NEXT_MODE_OFFSET (3 * __SIZEOF_POINTER__) -/** Offset of options member in fw_dynamic_info */ +/** Offset of options member in fw_dynamic_info (version >= 1) */ #define FW_DYNAMIC_INFO_OPTIONS_OFFSET (4 * __SIZEOF_POINTER__) +/** Offset of boot_hart member in fw_dynamic_info (version >= 2) */ +#define FW_DYNAMIC_INFO_BOOT_HART_OFFSET (5 * __SIZEOF_POINTER__) /** Expected value of info magic ('OSBI' ascii string in hex) */ #define FW_DYNAMIC_INFO_MAGIC_VALUE 0x4942534f /** Maximum supported info version */ -#define FW_DYNAMIC_INFO_VERSION_MAX 0x1 +#define FW_DYNAMIC_INFO_VERSION_MAX 0x2 /** Possible next mode values */ #define FW_DYNAMIC_INFO_NEXT_MODE_U 0x0 @@ -54,6 +56,22 @@ struct fw_dynamic_info { unsigned long next_mode; /** Options for OpenSBI library */ unsigned long options; + /** + * Preferred boot HART id + * + * It is possible that the previous booting stage uses same link + * address as the FW_DYNAMIC firmware. In this case, the relocation + * lottery mechanism can potentially overwrite the previous booting + * stage while other HARTs are still running in the previous booting + * stage leading to boot-time crash. To avoid this boot-time crash, + * the previous booting stage can specify last HART that will jump + * to the FW_DYNAMIC firmware as the preferred boot HART. + * + * To avoid specifying a preferred boot HART, the previous booting + * stage can set it to -1UL which will force the FW_DYNAMIC firmware + * to use the relocation lottery mechanism. + */ + unsigned long boot_hart; } __packed; #endif -- cgit v1.3.1