[PATCH v2 7/7] riscv: rely on core code to keep thread_info::cpu updated

Ard Biesheuvel
2021-09-30T12:59:22Z

Now that the core code switched back to using thread_info::cpu to keep
a task's CPU number, we no longer need to keep it in sync explicitly. So
just drop the code that does this.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
---
arch/riscv/kernel/asm-offsets.c | 1 -
arch/riscv/kernel/entry.S | 5 -----
arch/riscv/kernel/head.S | 1 -
3 files changed, 7 deletions(-)

diff --git a/arch/riscv/kernel/asm-offsets.c b/arch/riscv/kernel/asm-offsets.c
index 90f8ce64fa6f..478d9f02dab5 100644
--- a/arch/riscv/kernel/asm-offsets.c
+++ b/arch/riscv/kernel/asm-offsets.c
@@ -33,7 +33,6 @@ void asm_offsets(void)
OFFSET(TASK_TI_PREEMPT_COUNT, task_struct, thread_info.preempt_count);
OFFSET(TASK_TI_KERNEL_SP, task_struct, thread_info.kernel_sp);
OFFSET(TASK_TI_USER_SP, task_struct, thread_info.user_sp);
- OFFSET(TASK_TI_CPU, task_struct, thread_info.cpu);

OFFSET(TASK_THREAD_F0, task_struct, thread.fstate.f[0]);
OFFSET(TASK_THREAD_F1, task_struct, thread.fstate.f[1]);
diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S
index 98f502654edd..459eb1714353 100644
--- a/arch/riscv/kernel/entry.S
+++ b/arch/riscv/kernel/entry.S
@@ -544,11 +544,6 @@ ENTRY(__switch_to)
REG_L s9, TASK_THREAD_S9_RA(a4)
REG_L s10, TASK_THREAD_S10_RA(a4)
REG_L s11, TASK_THREAD_S11_RA(a4)
- /* Swap the CPU entry around. */
- lw a3, TASK_TI_CPU(a0)
- lw a4, TASK_TI_CPU(a1)
- sw a3, TASK_TI_CPU(a1)
- sw a4, TASK_TI_CPU(a0)
/* The offset of thread_info in task_struct is zero. */
move tp, a1
ret
diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S
index fce5184b22c3..d5ec30ef6f5d 100644
--- a/arch/riscv/kernel/head.S
+++ b/arch/riscv/kernel/head.S
@@ -317,7 +317,6 @@ clear_bss_done:
call setup_trap_vector
/* Restore C environment */
la tp, init_task
- sw zero, TASK_TI_CPU(tp)
la sp, init_thread_union + THREAD_SIZE

#ifdef CONFIG_KASAN
--
2.30.2