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riscv: smp: fail booting up smp if inconsistent vlen is detected

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Currently we only support Vector for SMP platforms, that is, all SMP
cores have the same vlenb. If we happen to detect a mismatching vlen, it
is better to just fail bootting it up to prevent further race/scheduling
issues.

Also, move .Lsecondary_park forward and chage `tail smp_callin` into a
regular call in the early assembly. So a core would be parked right
after a return from smp_callin. Note that a successful smp_callin
does not return.

Fixes: 7017858eb2d7 ("riscv: Introduce riscv_v_vsize to record size of Vector context")
Reported-by: Conor Dooley <conor.dooley@microchip.com>
Closes: https://lore.kernel.org/linux-riscv/20240228-vicinity-cornstalk-4b8eb5fe5730@spud/
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Yunhui Cui <cuiyunhui@bytedance.com>
Link: https://lore.kernel.org/r/20240510-zve-detection-v5-2-0711bdd26c12@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This commit is contained in:
Andy Chiu 2024-05-10 00:26:52 +08:00 committed by Palmer Dabbelt
parent 77afe3e514
commit 38a94c4666
No known key found for this signature in database
GPG Key ID: 2E1319F35FBB1889
2 changed files with 21 additions and 12 deletions
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19
arch/riscv/kernel/head.S
View File

@ -165,9 +165,20 @@ secondary_start_sbi:
#endif
call .Lsetup_trap_vector
scs_load_current
tail smp_callin
call smp_callin
#endif /* CONFIG_SMP */
.align 2
.Lsecondary_park:
/*
* Park this hart if we:
* - have too many harts on CONFIG_RISCV_BOOT_SPINWAIT
* - receive an early trap, before setup_trap_vector finished
* - fail in smp_callin(), as a successful one wouldn't return
*/
wfi
j .Lsecondary_park
.align 2
.Lsetup_trap_vector:
/* Set trap vector to exception handler */
@ -181,12 +192,6 @@ secondary_start_sbi:
csrw CSR_SCRATCH, zero
ret
.align 2
.Lsecondary_park:
/* We lack SMP support or have too many harts, so park this hart */
wfi
j .Lsecondary_park
SYM_CODE_END(_start)
SYM_CODE_START(_start_kernel)

14
arch/riscv/kernel/smpboot.c
View File

@ -214,6 +214,15 @@ asmlinkage __visible void smp_callin(void)
struct mm_struct *mm = &init_mm;
unsigned int curr_cpuid = smp_processor_id();
if (has_vector()) {
/*
* Return as early as possible so the hart with a mismatching
* vlen won't boot.
*/
if (riscv_v_setup_vsize())
return;
}
/* All kernel threads share the same mm context. */
mmgrab(mm);
current->active_mm = mm;
@ -226,11 +235,6 @@ asmlinkage __visible void smp_callin(void)
numa_add_cpu(curr_cpuid);
set_cpu_online(curr_cpuid, true);
if (has_vector()) {
if (riscv_v_setup_vsize())
elf_hwcap &= ~COMPAT_HWCAP_ISA_V;
}
riscv_user_isa_enable();
/*