From 28923f6b74060b183207a373ddae4ce4948cabea Mon Sep 17 00:00:00 2001 From: Liav Rehana Date: Thu, 15 Jun 2017 11:44:00 +0300 Subject: [PATCH] ARC: [plat-eznps] handle extra aux regs #2: kernel/entry exit Preserve eflags and gpa1 aux during entry/exit into kernel as these could be modified by kernel mode These registers used by compare exchange instructions. - GPA1 is used for compare value, - EFLAGS got bit reflects atomic operation response. EFLAGS is zeroed for each new user task so it won't get its parent value. Signed-off-by: Liav Rehana Signed-off-by: Noam Camus Signed-off-by: Vineet Gupta --- arch/arc/include/asm/entry-compact.h | 24 ++++++++++++++++++++++++ arch/arc/include/asm/ptrace.h | 5 +++++ arch/arc/kernel/process.c | 4 ++++ 3 files changed, 33 insertions(+) diff --git a/arch/arc/include/asm/entry-compact.h b/arch/arc/include/asm/entry-compact.h index 14c310f2e0b1..ec36d5b6d435 100644 --- a/arch/arc/include/asm/entry-compact.h +++ b/arch/arc/include/asm/entry-compact.h @@ -192,6 +192,12 @@ PUSHAX lp_start PUSHAX erbta +#ifdef CONFIG_ARC_PLAT_EZNPS + .word CTOP_INST_SCHD_RW + PUSHAX CTOP_AUX_GPA1 + PUSHAX CTOP_AUX_EFLAGS +#endif + lr r9, [ecr] st r9, [sp, PT_event] /* EV_Trap expects r9 to have ECR */ .endm @@ -208,6 +214,12 @@ * by hardware and that is not good. *-------------------------------------------------------------*/ .macro EXCEPTION_EPILOGUE +#ifdef CONFIG_ARC_PLAT_EZNPS + .word CTOP_INST_SCHD_RW + POPAX CTOP_AUX_EFLAGS + POPAX CTOP_AUX_GPA1 +#endif + POPAX erbta POPAX lp_start POPAX lp_end @@ -265,6 +277,12 @@ PUSHAX lp_end PUSHAX lp_start PUSHAX bta_l\LVL\() + +#ifdef CONFIG_ARC_PLAT_EZNPS + .word CTOP_INST_SCHD_RW + PUSHAX CTOP_AUX_GPA1 + PUSHAX CTOP_AUX_EFLAGS +#endif .endm /*-------------------------------------------------------------- @@ -277,6 +295,12 @@ * by hardware and that is not good. *-------------------------------------------------------------*/ .macro INTERRUPT_EPILOGUE LVL +#ifdef CONFIG_ARC_PLAT_EZNPS + .word CTOP_INST_SCHD_RW + POPAX CTOP_AUX_EFLAGS + POPAX CTOP_AUX_GPA1 +#endif + POPAX bta_l\LVL\() POPAX lp_start POPAX lp_end diff --git a/arch/arc/include/asm/ptrace.h b/arch/arc/include/asm/ptrace.h index 5297faa8a378..5a8cb22724a1 100644 --- a/arch/arc/include/asm/ptrace.h +++ b/arch/arc/include/asm/ptrace.h @@ -19,6 +19,11 @@ #ifdef CONFIG_ISA_ARCOMPACT struct pt_regs { +#ifdef CONFIG_ARC_PLAT_EZNPS + unsigned long eflags; /* Extended FLAGS */ + unsigned long gpa1; /* General Purpose Aux */ +#endif + /* Real registers */ unsigned long bta; /* bta_l1, bta_l2, erbta */ diff --git a/arch/arc/kernel/process.c b/arch/arc/kernel/process.c index 5c631a111240..5ac3b547453f 100644 --- a/arch/arc/kernel/process.c +++ b/arch/arc/kernel/process.c @@ -234,6 +234,10 @@ void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long usp) */ regs->status32 = STATUS_U_MASK | STATUS_L_MASK | ISA_INIT_STATUS_BITS; +#ifdef CONFIG_EZNPS_MTM_EXT + regs->eflags = 0; +#endif + /* bogus seed values for debugging */ regs->lp_start = 0x10; regs->lp_end = 0x80;