linux/arch/riscv/include/asm/scs.h
Sami Tolvanen c40fef858d
riscv: Use separate IRQ shadow call stacks
When both CONFIG_IRQ_STACKS and SCS are enabled, also use a separate
per-CPU shadow call stack.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20230927224757.1154247-13-samitolvanen@google.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-10-27 14:43:09 -07:00

55 lines
1.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_SCS_H
#define _ASM_SCS_H
#ifdef __ASSEMBLY__
#include <asm/asm-offsets.h>
#ifdef CONFIG_SHADOW_CALL_STACK
/* Load init_shadow_call_stack to gp. */
.macro scs_load_init_stack
la gp, init_shadow_call_stack
XIP_FIXUP_OFFSET gp
.endm
/* Load the per-CPU IRQ shadow call stack to gp. */
.macro scs_load_irq_stack tmp
load_per_cpu gp, irq_shadow_call_stack_ptr, \tmp
.endm
/* Load task_scs_sp(current) to gp. */
.macro scs_load_current
REG_L gp, TASK_TI_SCS_SP(tp)
.endm
/* Load task_scs_sp(current) to gp, but only if tp has changed. */
.macro scs_load_current_if_task_changed prev
beq \prev, tp, _skip_scs
scs_load_current
_skip_scs:
.endm
/* Save gp to task_scs_sp(current). */
.macro scs_save_current
REG_S gp, TASK_TI_SCS_SP(tp)
.endm
#else /* CONFIG_SHADOW_CALL_STACK */
.macro scs_load_init_stack
.endm
.macro scs_load_irq_stack tmp
.endm
.macro scs_load_current
.endm
.macro scs_load_current_if_task_changed prev
.endm
.macro scs_save_current
.endm
#endif /* CONFIG_SHADOW_CALL_STACK */
#endif /* __ASSEMBLY__ */
#endif /* _ASM_SCS_H */