lkml.org 
[lkml]   [2015]   [Jun]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 09/19] ARC: entry.S: FAKE_RET_FROM_EXCPN can always use r9
Date
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
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 e880a5f1b2e4..c976b54c9b07 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 6cced37e7a76..0a75f81e2853 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
--
1.9.1


\
 
 \ /
  Last update: 2015-06-07 11:01    [W:0.147 / U:0.124 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site