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 <vgupta@synopsys.com>
This commit is contained in:
Vineet Gupta 2013-07-09 15:07:13 +05:30
parent fe240f11cd
commit 37f3ac498c
3 changed files with 37 additions and 51 deletions

View File

@ -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

View File

@ -267,12 +267,7 @@ ARC_EXIT handle_interrupt_level1
ARC_ENTRY instr_service
EXCPN_PROLOG_FREEUP_REG r9
lr r9, [erstatus]
SWITCH_TO_KERNEL_STK
SAVE_ALL_SYS
EXCEPTION_PROLOGUE
lr r0, [efa]
mov r1, sp
@ -289,15 +284,13 @@ ARC_EXIT instr_service
ARC_ENTRY mem_service
EXCPN_PROLOG_FREEUP_REG r9
lr r9, [erstatus]
SWITCH_TO_KERNEL_STK
SAVE_ALL_SYS
EXCEPTION_PROLOGUE
lr r0, [efa]
mov r1, sp
FAKE_RET_FROM_EXCPN r9
bl do_memory_error
b ret_from_exception
ARC_EXIT mem_service
@ -308,11 +301,7 @@ ARC_EXIT mem_service
ARC_ENTRY EV_MachineCheck
EXCPN_PROLOG_FREEUP_REG r9
lr r9, [erstatus]
SWITCH_TO_KERNEL_STK
SAVE_ALL_SYS
EXCEPTION_PROLOGUE
lr r2, [ecr]
lr r0, [efa]
@ -342,13 +331,7 @@ ARC_EXIT EV_MachineCheck
ARC_ENTRY EV_TLBProtV
EXCPN_PROLOG_FREEUP_REG r9
;Which mode (user/kernel) was the system in when Exception occured
lr r9, [erstatus]
SWITCH_TO_KERNEL_STK
SAVE_ALL_SYS
EXCEPTION_PROLOGUE
;---------(3) Save some more regs-----------------
; vineetg: Mar 6th: Random Seg Fault issue #1
@ -406,12 +389,7 @@ ARC_EXIT EV_TLBProtV
; ---------------------------------------------
ARC_ENTRY EV_PrivilegeV
EXCPN_PROLOG_FREEUP_REG r9
lr r9, [erstatus]
SWITCH_TO_KERNEL_STK
SAVE_ALL_SYS
EXCEPTION_PROLOGUE
lr r0, [efa]
mov r1, sp
@ -427,14 +405,13 @@ ARC_EXIT EV_PrivilegeV
; ---------------------------------------------
ARC_ENTRY EV_Extension
EXCPN_PROLOG_FREEUP_REG r9
lr r9, [erstatus]
SWITCH_TO_KERNEL_STK
SAVE_ALL_SYS
EXCEPTION_PROLOGUE
lr r0, [efa]
mov r1, sp
FAKE_RET_FROM_EXCPN r9
bl do_extension_fault
b ret_from_exception
ARC_EXIT EV_Extension
@ -526,14 +503,7 @@ trap_with_param:
ARC_ENTRY EV_Trap
; Need at least 1 reg to code the early exception prolog
EXCPN_PROLOG_FREEUP_REG r9
;Which mode (user/kernel) was the system in when intr occured
lr r9, [erstatus]
SWITCH_TO_KERNEL_STK
SAVE_ALL_SYS
EXCEPTION_PROLOGUE
;------- (4) What caused the Trap --------------
lr r12, [ecr]

View File

@ -371,13 +371,7 @@ do_slow_path_pf:
; Slow path TLB Miss handled as a regular ARC Exception
; (stack switching / save the complete reg-file).
; That requires freeing up r9
EXCPN_PROLOG_FREEUP_REG r9
lr r9, [erstatus]
SWITCH_TO_KERNEL_STK
SAVE_ALL_SYS
EXCEPTION_PROLOGUE
; ------- setup args for Linux Page fault Hanlder ---------
mov_s r0, sp