diff options
| author | Anup Patel <[email protected]> | 2020-09-09 09:19:09 +0530 |
|---|---|---|
| committer | Anup Patel <[email protected]> | 2020-09-16 09:05:29 +0530 |
| commit | 172fa1601c7faaa01c547e8c498f5bdefd52d7cb (patch) | |
| tree | abd488410a942da16c3c06440bb3c91628431d4a /lib | |
| parent | 9f935a4a4372657e43b25fe2f4022fdeb3ca2387 (diff) | |
lib: sbi: Ensure coldboot HART supports next privilege mode
The coldboot HART jumps to the next booting stage at the end of
init_coldboot() so it is absolutely necessary for coldboot HART
to support the privilege mode expected by the next booting stage.
We extend the coldboot HART selection in sbi_init() to ensure that
the selected coldboot HART always supports privilege mode specified
in scratch space (i.e. scratch->next_mode). This will further help
us allow E-core (without MMU) on SiFive Unleashed and PolarFire
ICICLE boards to proceed further and wait in HSM STOPPED state.
Signed-off-by: Anup Patel <[email protected]>
Reviewed-by: Atish Patra <[email protected]>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/sbi/sbi_init.c | 29 |
1 files changed, 28 insertions, 1 deletions
diff --git a/lib/sbi/sbi_init.c b/lib/sbi/sbi_init.c index e1a1d96d..65d81bac 100644 --- a/lib/sbi/sbi_init.c +++ b/lib/sbi/sbi_init.c @@ -295,6 +295,7 @@ static atomic_t coldboot_lottery = ATOMIC_INITIALIZER(0); */ void __noreturn sbi_init(struct sbi_scratch *scratch) { + bool next_mode_supported = FALSE; bool coldboot = FALSE; u32 hartid = current_hartid(); const struct sbi_platform *plat = sbi_platform_ptr(scratch); @@ -303,7 +304,33 @@ void __noreturn sbi_init(struct sbi_scratch *scratch) sbi_platform_hart_invalid(plat, hartid)) sbi_hart_hang(); - if (atomic_xchg(&coldboot_lottery, 1) == 0) + switch (scratch->next_mode) { + case PRV_M: + next_mode_supported = TRUE; + break; + case PRV_S: + if (misa_extension('S')) + next_mode_supported = TRUE; + break; + case PRV_U: + if (misa_extension('U')) + next_mode_supported = TRUE; + break; + default: + sbi_hart_hang(); + } + + /* + * Only the HART supporting privilege mode specified in the + * scratch->next_mode should be allowed to become the coldboot + * HART because the coldboot HART will be directly jumping to + * the next booting stage. + * + * We use a lottery mechanism to select coldboot HART among + * HARTs which satisfy above condition. + */ + + if (next_mode_supported && atomic_xchg(&coldboot_lottery, 1) == 0) coldboot = TRUE; if (coldboot) |