From 9b8c7d1e7107c30a50aae27c1f33fe706c8c6c67 Mon Sep 17 00:00:00 2001 From: Vineet Gupta Date: Fri, 27 Feb 2015 16:43:08 +0530 Subject: [PATCH] ARC: entry.S: FAKE_RET_FROM_EXCPN can always use r9 Signed-off-by: Vineet Gupta --- arch/arc/include/asm/entry.h | 16 ++++++++-------- arch/arc/kernel/entry.S | 24 +++++++++++------------- 2 files changed, 19 insertions(+), 21 deletions(-) diff --git a/arch/arc/include/asm/entry.h b/arch/arc/include/asm/entry.h index f3927a1..408a713 100644 --- a/arch/arc/include/asm/entry.h +++ b/arch/arc/include/asm/entry.h @@ -331,14 +331,14 @@ * Look at EV_ProtV to see how this is actually used *-------------------------------------------------------------*/ -.macro FAKE_RET_FROM_EXCPN reg - - ld \reg, [sp, PT_status32] - bic \reg, \reg, (STATUS_U_MASK|STATUS_DE_MASK) - bset \reg, \reg, STATUS_L_BIT - sr \reg, [erstatus] - mov \reg, 55f - sr \reg, [eret] +.macro FAKE_RET_FROM_EXCPN + + ld r9, [sp, PT_status32] + bic r9, r9, (STATUS_U_MASK|STATUS_DE_MASK) + bset r9, r9, STATUS_L_BIT + sr r9, [erstatus] + mov r9, 55f + sr r9, [eret] rtie 55: diff --git a/arch/arc/kernel/entry.S b/arch/arc/kernel/entry.S index 6cced37e..0a75f81 100644 --- a/arch/arc/kernel/entry.S +++ b/arch/arc/kernel/entry.S @@ -261,7 +261,7 @@ ENTRY(instr_service) lr r0, [efa] mov r1, sp - FAKE_RET_FROM_EXCPN r9 + FAKE_RET_FROM_EXCPN bl do_insterror_or_kprobe b ret_from_exception @@ -278,7 +278,7 @@ ENTRY(mem_service) lr r0, [efa] mov r1, sp - FAKE_RET_FROM_EXCPN r9 + FAKE_RET_FROM_EXCPN bl do_memory_error b ret_from_exception @@ -330,12 +330,11 @@ ENTRY(EV_TLBProtV) lr r2, [ecr] lr r0, [efa] ; Faulting Data address - ; --------(4) Return from CPU Exception Mode --------- - ; Fake a rtie, but rtie to next label - ; That way, subsequently, do_page_fault ( ) executes in pure kernel - ; mode with further Exceptions enabled + ; Exception auto-disables further Intr/exceptions. + ; Re-enable them by pretending to return from exception + ; (so rest of handler executes in pure K mode) - FAKE_RET_FROM_EXCPN r9 + FAKE_RET_FROM_EXCPN mov r1, sp @@ -377,7 +376,7 @@ ENTRY(call_do_page_fault) EXCEPTION_PROLOGUE lr r0, [efa] ; Faulting Data address mov r1, sp - FAKE_RET_FROM_EXCPN r9 + FAKE_RET_FROM_EXCPN mov blink, ret_from_exception b do_page_fault @@ -394,7 +393,7 @@ ENTRY(EV_PrivilegeV) lr r0, [efa] mov r1, sp - FAKE_RET_FROM_EXCPN r9 + FAKE_RET_FROM_EXCPN bl do_privilege_fault b ret_from_exception @@ -410,7 +409,7 @@ ENTRY(EV_Extension) lr r0, [efa] mov r1, sp - FAKE_RET_FROM_EXCPN r9 + FAKE_RET_FROM_EXCPN bl do_extension_fault b ret_from_exception @@ -472,7 +471,7 @@ trap_with_param: ; Now that we have read EFA, it is safe to do "fake" rtie ; and get out of CPU exception mode - FAKE_RET_FROM_EXCPN r11 + FAKE_RET_FROM_EXCPN ; Save callee regs in case gdb wants to have a look ; SP will grow up by size of CALLEE Reg-File @@ -512,8 +511,7 @@ ENTRY(EV_Trap) ; ======= (5a) Trap is due to System Call ======== - ; Before doing anything, return from CPU Exception Mode - FAKE_RET_FROM_EXCPN r11 + FAKE_RET_FROM_EXCPN ; If syscall tracing ongoing, invoke pre-pos-hooks GET_CURR_THR_INFO_FLAGS r10 -- 2.7.4