diff options
| author | Atish Patra | 2022-01-20 01:09:13 -0800 |
|---|---|---|
| committer | Palmer Dabbelt | 2022-01-20 09:26:59 -0800 |
| commit | 9a2451f1866344d38b4a1dc20396e3a03954fcd7 (patch) | |
| tree | 554497f0f45fad78ebdbed0e32e3470eea8adbbc /arch/riscv/kernel/head.S | |
| parent | 3938d5a2f9369d1ebd56320629fed395ce327e9c (diff) | |
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/kernel/head.S')
| -rw-r--r-- | arch/riscv/kernel/head.S | 19 |
1 files changed, 10 insertions, 9 deletions
diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S index db4be6a7e392..05ea372e1909 100644 --- a/arch/riscv/kernel/head.S +++ b/arch/riscv/kernel/head.S @@ -11,6 +11,7 @@ #include <asm/page.h> #include <asm/pgtable.h> #include <asm/csr.h> +#include <asm/cpu_ops_sbi.h> #include <asm/hwcap.h> #include <asm/image.h> #include "efi-header.S" @@ -168,15 +169,15 @@ secondary_start_sbi: la a3, .Lsecondary_park csrw CSR_TVEC, a3 - slli a3, a0, LGREG - la a4, __cpu_up_stack_pointer - XIP_FIXUP_OFFSET a4 - la a5, __cpu_up_task_pointer - XIP_FIXUP_OFFSET a5 - add a4, a3, a4 - add a5, a3, a5 - REG_L sp, (a4) - REG_L tp, (a5) + /* a0 contains the hartid & a1 contains boot data */ + li a2, SBI_HART_BOOT_TASK_PTR_OFFSET + XIP_FIXUP_OFFSET a2 + add a2, a2, a1 + REG_L tp, (a2) + li a3, SBI_HART_BOOT_STACK_PTR_OFFSET + XIP_FIXUP_OFFSET a3 + add a3, a3, a1 + REG_L sp, (a3) .Lsecondary_start_common: |