From: Mukesh Kumar Chaurasiya <[email protected]> Add PowerPC-specific implementations of the generic syscall exit hooks used by the generic entry/exit framework:
- arch_exit_to_user_mode_work_prepare() - arch_exit_to_user_mode_work() These helpers handle user state restoration when returning from the kernel to userspace, including FPU/VMX/VSX state, transactional memory, KUAP restore, and per-CPU accounting. Additionally, move check_return_regs_valid() from interrupt.c to interrupt.h so it can be shared by the new entry/exit logic. No functional change is intended with this patch. Signed-off-by: Mukesh Kumar Chaurasiya <[email protected]> --- arch/powerpc/include/asm/entry-common.h | 49 +++++++++++++++++++++++++ 1 file changed, 49 insertions(+) diff --git a/arch/powerpc/include/asm/entry-common.h b/arch/powerpc/include/asm/entry-common.h index 837a7e020e82..ff0625e04778 100644 --- a/arch/powerpc/include/asm/entry-common.h +++ b/arch/powerpc/include/asm/entry-common.h @@ -6,6 +6,7 @@ #include <asm/cputime.h> #include <asm/interrupt.h> #include <asm/stacktrace.h> +#include <asm/switch_to.h> #include <asm/tm.h> static __always_inline void booke_load_dbcr0(void) @@ -123,4 +124,52 @@ static __always_inline void arch_enter_from_user_mode(struct pt_regs *regs) #define arch_enter_from_user_mode arch_enter_from_user_mode +static inline void arch_exit_to_user_mode_prepare(struct pt_regs *regs, + unsigned long ti_work) +{ + unsigned long mathflags; + + if (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && IS_ENABLED(CONFIG_PPC_FPU)) { + if (IS_ENABLED(CONFIG_PPC_TRANSACTIONAL_MEM) && + unlikely((ti_work & _TIF_RESTORE_TM))) { + restore_tm_state(regs); + } else { + mathflags = MSR_FP; + + if (cpu_has_feature(CPU_FTR_VSX)) + mathflags |= MSR_VEC | MSR_VSX; + else if (cpu_has_feature(CPU_FTR_ALTIVEC)) + mathflags |= MSR_VEC; + + /* + * If userspace MSR has all available FP bits set, + * then they are live and no need to restore. If not, + * it means the regs were given up and restore_math + * may decide to restore them (to avoid taking an FP + * fault). + */ + if ((regs->msr & mathflags) != mathflags) + restore_math(regs); + } + } + + check_return_regs_valid(regs); +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM + local_paca->tm_scratch = regs->msr; +#endif + /* Restore user access locks last */ + kuap_user_restore(regs); +} + +#define arch_exit_to_user_mode_prepare arch_exit_to_user_mode_prepare + +static __always_inline void arch_exit_to_user_mode(void) +{ + booke_load_dbcr0(); + + account_cpu_user_exit(); +} + +#define arch_exit_to_user_mode arch_exit_to_user_mode + #endif /* _ASM_PPC_ENTRY_COMMON_H */ -- 2.52.0
