ARC: entry.S: comments cleanup (4bf4564b) · Commits · e / devices / android_kernel_fairphone_FP3

arch/arc/kernel/entry.S

+20 −26

Original line number	Diff line number	Diff line
		@@ -322,13 +322,8 @@ ENTRY(EV_TLBProtV)

		EXCEPTION_PROLOGUE

		;---------(3) Save some more regs-----------------
		; vineetg: Mar 6th: Random Seg Fault issue #1
		; ecr and efa were not saved in case an Intr sneaks in
		; after fake rtie

		lr r2, [ecr]
		lr r0, [efa] ; Faulting Data address
		lr r0, [efa] ; Faulting Data addr (not part of pt_regs saved above)

		; Exception auto-disables further Intr/exceptions.
		; Re-enable them by pretending to return from exception
		@@ -336,7 +331,7 @@ ENTRY(EV_TLBProtV)

		FAKE_RET_FROM_EXCPN

		mov r1, sp
		mov r1, sp ; Handle to pt_regs

		;------ (5) Type of Protection Violation? ----------
		;
		@@ -415,8 +410,11 @@ ENTRY(EV_Extension)
		b ret_from_exception
		END(EV_Extension)

		;######################### System Call Tracing #########################
		;################ Trap Handling (Syscall, Breakpoint) ##################

		; ---------------------------------------------
		; syscall Tracing
		; ---------------------------------------------
		tracesys:
		; save EFA in case tracer wants the PC of traced task
		; using ERET won't work since next-PC has already committed
		@@ -459,10 +457,9 @@ tracesys_exit:
		b ret_from_exception ; NOT ret_from_system_call at is saves r0 which
		; we'd done before calling post hook above

		;################### Break Point TRAP ##########################

		; ======= (5b) Trap is due to Break-Point =========

		; ---------------------------------------------
		; Breakpoint TRAP
		; ---------------------------------------------
		trap_with_param:

		; stop_pc info by gdb needs this info
		@@ -490,36 +487,33 @@ trap_with_param:

		b ret_from_exception

		;##################### Trap Handling ##############################
		;
		; EV_Trap caused by TRAP_S and TRAP0 instructions.
		;------------------------------------------------------------------
		; (1) System Calls
		; :parameters in r0-r7.
		; :r8 has the system call number
		; (2) Break Points
		;------------------------------------------------------------------
		; ---------------------------------------------
		; syscall TRAP
		; ABI: (r0-r7) upto 8 args, (r8) syscall number
		; ---------------------------------------------

		ENTRY(EV_Trap)

		EXCEPTION_PROLOGUE

		;------- (4) What caused the Trap --------------
		;============ TRAP 1 :breakpoints
		lr r10, [ecr]
		bmsk.f 0, r10, 7
		bnz trap_with_param

		; ======= (5a) Trap is due to System Call ========
		;============ TRAP (no param): syscall top level

		; First return from Exception to pure K mode (Exception/IRQs renabled)
		FAKE_RET_FROM_EXCPN

		; If syscall tracing ongoing, invoke pre-pos-hooks
		; If syscall tracing ongoing, invoke pre-post-hooks
		GET_CURR_THR_INFO_FLAGS r10
		btst r10, TIF_SYSCALL_TRACE
		bnz tracesys ; this never comes back

		;============ This is normal System Call case ==========
		; Sys-call num shd not exceed the total system calls avail
		;============ Normal syscall case

		; syscall num shd not exceed the total system calls avail
		cmp r8, NR_syscalls
		mov.hi r0, -ENOSYS
		bhi ret_from_system_call