ARC: entry.S: FAKE_RET_FROM_EXCPN can always use r9

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

diff --git a/arch/arc/include/asm/entry.h b/arch/arc/include/asm/entry.h
index f3927a156efb53e5a761f2626812f3b1354633bc..408a71378b5eee2662e8873a86104aa9e3188edb 100644 (file)
--- 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 6cced37e7a76b6f44794d2e037321c520c57e264..0a75f81e285307038949d00059f49087c4e6ba8f 100644 (file)
--- 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