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author | Atish Patra <atishp@rivosinc.com> | 2022-01-20 01:09:13 -0800 |
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committer | Palmer Dabbelt <palmer@rivosinc.com> | 2022-01-20 09:26:59 -0800 |
commit | 9a2451f1866344d38b4a1dc20396e3a03954fcd7 (patch) | |
tree | 554497f0f45fad78ebdbed0e32e3470eea8adbbc /arch/riscv/include/asm/cpu_ops_sbi.h | |
parent | 3938d5a2f9369d1ebd56320629fed395ce327e9c (diff) | |
download | lwn-9a2451f1866344d38b4a1dc20396e3a03954fcd7.tar.gz lwn-9a2451f1866344d38b4a1dc20396e3a03954fcd7.zip |
RISC-V: Avoid using per cpu array for ordered booting
Currently both order booting and spinwait approach uses a per cpu
array to update stack & task pointer. This approach will not work for the
following cases.
1. If NR_CPUs are configured to be less than highest hart id.
2. A platform has sparse hartid.
This issue can be fixed for ordered booting as the booting cpu brings up
one cpu at a time using SBI HSM extension which has opaque parameter
that is unused until now.
Introduce a common secondary boot data structure that can store the stack
and task pointer. Secondary harts will use this data while booting up
to setup the sp & tp.
Reviewed-by: Anup Patel <anup@brainfault.org>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch/riscv/include/asm/cpu_ops_sbi.h')
-rw-r--r-- | arch/riscv/include/asm/cpu_ops_sbi.h | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/arch/riscv/include/asm/cpu_ops_sbi.h b/arch/riscv/include/asm/cpu_ops_sbi.h new file mode 100644 index 000000000000..56e4b76d09ff --- /dev/null +++ b/arch/riscv/include/asm/cpu_ops_sbi.h @@ -0,0 +1,25 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (c) 2021 by Rivos Inc. + */ +#ifndef __ASM_CPU_OPS_SBI_H +#define __ASM_CPU_OPS_SBI_H + +#ifndef __ASSEMBLY__ +#include <linux/init.h> +#include <linux/sched.h> +#include <linux/threads.h> + +/** + * struct sbi_hart_boot_data - Hart specific boot used during booting and + * cpu hotplug. + * @task_ptr: A pointer to the hart specific tp + * @stack_ptr: A pointer to the hart specific sp + */ +struct sbi_hart_boot_data { + void *task_ptr; + void *stack_ptr; +}; +#endif + +#endif /* ifndef __ASM_CPU_OPS_SBI_H */ |