From 37f3ac498c988536f0d42b4659fb5d2c050b2f96 Mon Sep 17 00:00:00 2001 From: Vineet Gupta Date: Tue, 9 Jul 2013 15:07:13 +0530 Subject: ARC: Exception Handlers Code consolidation After the recent cleanups, all the exception handlers now have same boilerplate prologue code. Move that into common macro. This reduces readability but helps greatly with sharing / duplicating entry code with ARCv2 ISA where the handlers are pretty much the same, just the entry prologue is different (due to hardware assist). Also while at it, add the missing FAKE_RET_FROM_EXCPN calls in couple of places to drop down to pure kernel mode (from exception mode) before jumping off into "C" code. Signed-off-by: Vineet Gupta --- arch/arc/include/asm/entry.h | 24 +++++++++++++++++++++++- 1 file changed, 23 insertions(+), 1 deletion(-) (limited to 'arch/arc/include/asm') diff --git a/arch/arc/include/asm/entry.h b/arch/arc/include/asm/entry.h index df57611652e5..884081099f80 100644 --- a/arch/arc/include/asm/entry.h +++ b/arch/arc/include/asm/entry.h @@ -365,7 +365,7 @@ * it to memory (non-SMP case) or SCRATCH0 Aux Reg (SMP). * * Before saving the full regfile - this reg is restored back, only - * to be saved again on kernel mode stack, as part of ptregs. + * to be saved again on kernel mode stack, as part of pt_regs. *-------------------------------------------------------------*/ .macro EXCPN_PROLOG_FREEUP_REG reg #ifdef CONFIG_SMP @@ -383,6 +383,28 @@ #endif .endm +/*-------------------------------------------------------------- + * Exception Entry prologue + * -Switches stack to K mode (if not already) + * -Saves the register file + * + * After this it is safe to call the "C" handlers + *-------------------------------------------------------------*/ +.macro EXCEPTION_PROLOGUE + + /* Need at least 1 reg to code the early exception prologue */ + EXCPN_PROLOG_FREEUP_REG r9 + + /* U/K mode at time of exception (stack not switched if already K) */ + lr r9, [erstatus] + + /* ARC700 doesn't provide auto-stack switching */ + SWITCH_TO_KERNEL_STK + + /* save the regfile */ + SAVE_ALL_SYS +.endm + /*-------------------------------------------------------------- * Save all registers used by Exceptions (TLB Miss, Prot-V, Mem err etc) * Requires SP to be already switched to kernel mode Stack -- cgit v1.2.1