sh2(A) exception handler update

This patch is

By sh2
- Remove duplicate code
- Reduce stack usage
- Cleanup and little optimize

By sh2a
- Add missing handler(256 to 511)
- Use sh2a instructions handler

Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

diff --git a/arch/sh/kernel/cpu/sh2/entry.S b/arch/sh/kernel/cpu/sh2/entry.S
index 0fc8906..ee894e5 100644 (file)
--- a/arch/sh/kernel/cpu/sh2/entry.S
+++ b/arch/sh/kernel/cpu/sh2/entry.S
@@ -3,7 +3,7 @@
  *
  * The SH-2 exception entry
  *
- * Copyright (C) 2005,2006 Yoshinori Sato
+ * Copyright (C) 2005-2008 Yoshinori Sato
  * Copyright (C) 2005  AXE,Inc.
  *
  * This file is subject to the terms and conditions of the GNU General Public
@@ -36,43 +36,41 @@ OFF_TRA     =  (16*4+6*4)
 #include <asm/entry-macros.S>
 
 ENTRY(exception_handler)
-       ! already saved r0/r1
+       ! stack
+       ! r0 <- point sp
+       ! r1
+       ! pc
+       ! sr
+       ! r0 = temporary
+       ! r1 = vector (pseudo EXPEVT / INTEVT / TRA)
        mov.l   r2,@-sp
        mov.l   r3,@-sp
-       mov     r0,r1
        cli
        mov.l   $cpu_mode,r2
        mov.l   @r2,r0
        mov.l   @(5*4,r15),r3   ! previous SR
-       shll2   r3              ! set "S" flag
-       rotl    r0              ! T <- "S" flag
-       rotl    r0              ! "S" flag is LSB
-       rotcr   r3              ! T -> r3:b30
-       shlr    r3
-       shlr    r0
-       bt/s    1f
-        mov.l  r3,@(5*4,r15)   ! copy cpu mode to SR
+       or      r0,r3           ! set MD
+       tst     r0,r0
+       bf/s    1f              ! previous mode check
+        mov.l  r3,@(5*4,r15)   ! update SR
        ! switch to kernel mode
-       mov     #1,r0
-       rotr    r0
-       rotr    r0
+       mov.l   __md_bit,r0
        mov.l   r0,@r2          ! enter kernel mode
        mov.l   $current_thread_info,r2
        mov.l   @r2,r2
-       mov     #0x20,r0
+       mov     #(THREAD_SIZE >> 8),r0
        shll8   r0
        add     r2,r0
        mov     r15,r2          ! r2 = user stack top
        mov     r0,r15          ! switch kernel stack
-       add     #-4,r15         ! dummy
        mov.l   r1,@-r15        ! TRA
        sts.l   macl, @-r15
        sts.l   mach, @-r15
        stc.l   gbr, @-r15
-       mov.l   @(4*4,r2),r0
-       mov.l   @(5*4,r2),r1
-       mov.l   r1,@-r15        ! original SR
+       mov.l   @(5*4,r2),r0
+       mov.l   r0,@-r15        ! original SR
        sts.l   pr,@-r15
+       mov.l   @(4*4,r2),r0
        mov.l   r0,@-r15        ! original PC
        mov     r2,r3
        add     #(4+2)*4,r3     ! rewind r0 - r3 + exception frame
@@ -88,14 +86,15 @@ ENTRY(exception_handler)
        mov.l   r6,@-r15
        mov.l   r5,@-r15
        mov.l   r4,@-r15
+       mov     r1,r9           ! save TRA
        mov     r2,r8           ! copy user -> kernel stack
-       mov.l   @r8+,r3
+       mov.l   @(0,r8),r3
        mov.l   r3,@-r15
-       mov.l   @r8+,r2
+       mov.l   @(4,r8),r2
        mov.l   r2,@-r15
-       mov.l   @r8+,r1
+       mov.l   @(12,r8),r1
        mov.l   r1,@-r15
-       mov.l   @r8+,r0
+       mov.l   @(8,r8),r0
        bra     2f
         mov.l  r0,@-r15
 1:
@@ -107,10 +106,11 @@ ENTRY(exception_handler)
        mov.l   r0,@-r15        
        mov.l   @r2+,r0         ! old R2
        mov.l   r0,@-r15        
-       mov.l   @r2+,r0         ! old R1
-       mov.l   r0,@-r15        
-       mov.l   @r2+,r0         ! old R0
+       mov.l   @(4,r2),r0      ! old R1
        mov.l   r0,@-r15        
+       mov.l   @r2,r0          ! old R0
+       mov.l   r0,@-r15
+       add     #8,r2
        mov.l   @r2+,r3         ! old PC
        mov.l   @r2+,r0         ! old SR
        add     #-4,r2          ! exception frame stub (sr)
@@ -135,14 +135,12 @@ ENTRY(exception_handler)
        mov.l   r6,@-r2
        mov.l   r5,@-r2
        mov.l   r4,@-r2
+       mov     r1,r9
        mov.l   @(OFF_R0,r15),r0
        mov.l   @(OFF_R1,r15),r1
        mov.l   @(OFF_R2,r15),r2
        mov.l   @(OFF_R3,r15),r3
 2:
-       mov     #OFF_TRA,r8
-       add     r15,r8
-       mov.l   @r8,r9  
        mov     #64,r8
        cmp/hs  r8,r9
        bt      interrupt_entry ! vec >= 64 is interrupt
@@ -150,26 +148,14 @@ ENTRY(exception_handler)
        cmp/hs  r8,r9
        bt      trap_entry      ! 64 > vec >= 32  is trap
 
-#if defined(CONFIG_SH_FPU)
-       mov     #13,r8
-       cmp/eq  r8,r9
-       bt      10f             ! fpu
-       nop
-#endif
-
        mov.l   4f,r8
        mov     r9,r4
        shll2   r9
        add     r9,r8
-       mov.l   @r8,r8
-       mov     #0,r9
-       cmp/eq  r9,r8
+       mov.l   @r8,r8          ! exception handler address
+       tst     r8,r8
        bf      3f
        mov.l   8f,r8           ! unhandled exception
-#if defined(CONFIG_SH_FPU)
-10:
-       mov.l   9f, r8          ! unhandled exception
-#endif
 3:
        mov.l   5f,r10
        jmp     @r8
@@ -188,10 +174,7 @@ interrupt_entry:
 5:     .long   ret_from_exception
 6:     .long   ret_from_irq
 7:     .long   do_IRQ
-8:     .long   do_exception_error
-#ifdef CONFIG_SH_FPU
-9:     .long   fpu_error_trap_handler
-#endif
+8:     .long   exception_error
 
 trap_entry:
        mov     #0x30,r8
@@ -200,24 +183,9 @@ trap_entry:
        add     #-0x10,r9       ! convert SH2 to SH3/4 ABI
 1:     
        shll2   r9                      ! TRA
-       mov     #OFF_TRA,r8
-       add     r15,r8
-       mov.l   r9,@r8
-       mov     r9,r8
-#ifdef CONFIG_TRACE_IRQFLAGS
-       mov.l   2f, r9
-       jsr     @r9
-        nop
-#endif
-       sti
-       bra     system_call
-        nop
+       bra     system_call     ! jump common systemcall entry
+        mov    r9,r8
        
-       .align  2
-#ifdef CONFIG_TRACE_IRQFLAGS
-2:     .long   trace_hardirqs_on
-#endif
-
 #if defined(CONFIG_SH_STANDARD_BIOS)
        /* Unwind the stack and jmp to the debug entry */
 ENTRY(sh_bios_handler)
@@ -240,7 +208,7 @@ ENTRY(sh_bios_handler)
        mov.l   @r2,r2
        stc     sr,r3
        mov.l   r2,@r0
-       mov.l   r3,@r0
+       mov.l   r3,@(4,r0)
        mov.l   r1,@(8,r0)      
        mov.l   @r15+, r0
        mov.l   @r15+, r1
@@ -272,22 +240,30 @@ ENTRY(address_error_trap_handler)
        mov.l   1f,r0
        jmp     @r0
         mov    #0,r5                           ! writeaccess is unknown
-       .align  2
 
+       .align  2
 1:     .long   do_address_error
 
 restore_all:
-       cli
-#ifdef CONFIG_TRACE_IRQFLAGS
-       mov.l   1f, r0
-       jsr     @r0
-        nop
-#endif
+       stc     sr,r0
+       or      #0xf0,r0
+       ldc     r0,sr                           ! all interrupt block (same BL = 1)
+       ! restore special register
+       ! overlap exception frame
+       mov     r15,r0
+       add     #17*4,r0
+       lds.l   @r0+,pr
+       add     #4,r0
+       ldc.l   @r0+,gbr
+       lds.l   @r0+,mach
+       lds.l   @r0+,macl
        mov     r15,r0
        mov.l   $cpu_mode,r2
        mov     #OFF_SR,r3
        mov.l   @(r0,r3),r1
-       mov.l   r1,@r2
+       mov.l   __md_bit,r3
+       and     r1,r3                           ! copy MD bit
+       mov.l   r3,@r2
        shll2   r1                              ! clear MD bit
        shlr2   r1
        mov.l   @(OFF_SP,r0),r2
@@ -297,12 +273,6 @@ restore_all:
        mov     #OFF_PC,r3
        mov.l   @(r0,r3),r1
        mov.l   r1,@r2                          ! set pc
-       add     #4*16+4,r0
-       lds.l   @r0+,pr
-       add     #4,r0                           ! skip sr
-       ldc.l   @r0+,gbr
-       lds.l   @r0+,mach
-       lds.l   @r0+,macl
        get_current_thread_info r0, r1
        mov.l   $current_thread_info,r1
        mov.l   r0,@r1
@@ -326,9 +296,8 @@ restore_all:
         nop
 
        .align 2
-#ifdef CONFIG_TRACE_IRQFLAGS
-1:     .long   trace_hardirqs_off
-#endif
+__md_bit:
+       .long   0x40000000
 $current_thread_info:
        .long   __current_thread_info
 $cpu_mode:     

diff --git a/arch/sh/kernel/cpu/sh2/ex.S b/arch/sh/kernel/cpu/sh2/ex.S
index 6d285af..85b0bf8 100644 (file)
--- a/arch/sh/kernel/cpu/sh2/ex.S
+++ b/arch/sh/kernel/cpu/sh2/ex.S
@@ -18,16 +18,17 @@
 exception_entry:       
 no     =       0
        .rept   256
-       mov.l   r0,@-sp
-       mov     #no,r0
+       mov.l   r1,@-sp
        bra     exception_trampoline
-       and     #0xff,r0
+       mov     #no,r1
 no     =       no + 1
        .endr
 exception_trampoline:
-       mov.l   r1,@-sp
-       mov.l   $exception_handler,r1
-       jmp     @r1
+       mov.l   r0,@-sp
+       mov.l   $exception_handler,r0
+       extu.b  r1,r1
+       jmp     @r0
+         extu.w        r1,r1
 
        .align  2
 $exception_entry:
@@ -41,6 +42,6 @@ $exception_handler:
 ENTRY(vbr_base)
 vector =       0
        .rept   256
-       .long   exception_entry + vector * 8
+       .long   exception_entry + vector * 6
 vector =       vector + 1
        .endr

diff --git a/arch/sh/kernel/cpu/sh2a/Makefile b/arch/sh/kernel/cpu/sh2a/Makefile
index 7e2b90c..1ab1ecf 100644 (file)
--- a/arch/sh/kernel/cpu/sh2a/Makefile
+++ b/arch/sh/kernel/cpu/sh2a/Makefile
@@ -4,7 +4,7 @@
 
 obj-y  := common.o probe.o opcode_helper.o
 
-common-y       += $(addprefix ../sh2/, ex.o entry.o)
+common-y       += ex.o entry.o
 
 obj-$(CONFIG_SH_FPU)   += fpu.o
 

diff --git a/arch/sh/kernel/cpu/sh2a/entry.S b/arch/sh/kernel/cpu/sh2a/entry.S
new file mode 100644 (file)
index 0000000..47096dc
--- /dev/null
+++ b/arch/sh/kernel/cpu/sh2a/entry.S
@@ -0,0 +1,249 @@
+/*
+ * arch/sh/kernel/cpu/sh2a/entry.S
+ *
+ * The SH-2A exception entry
+ *
+ * Copyright (C) 2008 Yoshinori Sato
+ * Based on arch/sh/kernel/cpu/sh2/entry.S
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/linkage.h>
+#include <asm/asm-offsets.h>
+#include <asm/thread_info.h>
+#include <asm/cpu/mmu_context.h>
+#include <asm/unistd.h>
+#include <asm/errno.h>
+#include <asm/page.h>
+       
+/* Offsets to the stack */
+OFF_R0  =  0           /* Return value. New ABI also arg4 */
+OFF_R1  =  4           /* New ABI: arg5 */
+OFF_R2  =  8           /* New ABI: arg6 */
+OFF_R3  =  12          /* New ABI: syscall_nr */
+OFF_R4  =  16          /* New ABI: arg0 */
+OFF_R5  =  20          /* New ABI: arg1 */
+OFF_R6  =  24          /* New ABI: arg2 */
+OFF_R7  =  28          /* New ABI: arg3 */
+OFF_SP =  (15*4)
+OFF_PC  =  (16*4)
+OFF_SR =  (16*4+2*4)
+OFF_TRA        =  (16*4+6*4)
+
+#include <asm/entry-macros.S>
+
+ENTRY(exception_handler)
+       ! stack
+       ! r0 <- point sp
+       ! r1
+       ! pc
+       ! sr
+       ! r0 = temporary
+       ! r1 = vector (pseudo EXPEVT / INTEVT / TRA)
+       mov.l   r2,@-sp
+       cli
+       mov.l   $cpu_mode,r2
+       bld.b   #6,@(0,r2)      !previus SR.MD
+       bst.b   #6,@(4*4,r15)   !set cpu mode to SR.MD
+       bt      1f
+       ! switch to kernel mode
+       bset.b  #6,@(0,r2)      !set SR.MD
+       mov.l   $current_thread_info,r2
+       mov.l   @r2,r2
+       mov     #(THREAD_SIZE >> 8),r0
+       shll8   r0
+       add     r2,r0           ! r0 = kernel stack tail
+       mov     r15,r2          ! r2 = user stack top
+       mov     r0,r15          ! switch kernel stack
+       mov.l   r1,@-r15        ! TRA
+       sts.l   macl, @-r15
+       sts.l   mach, @-r15
+       stc.l   gbr, @-r15
+       mov.l   @(4*4,r2),r0
+       mov.l   r0,@-r15        ! original SR
+       sts.l   pr,@-r15
+       mov.l   @(3*4,r2),r0
+       mov.l   r0,@-r15        ! original PC
+       mov     r2,r0
+       add     #(3+2)*4,r0     ! rewind r0 - r3 + exception frame
+       lds     r0,pr           ! pr = original SP
+       movmu.l r3,@-r15        ! save regs
+       mov     r2,r8           ! r8 =  previus stack top
+       mov     r1,r9           ! r9 = interrupt vector
+       ! restore previous stack
+       mov.l   @r8+,r2
+       mov.l   @r8+,r0
+       mov.l   @r8+,r1
+       bra     2f
+        movml.l r2,@-r15
+1:
+       ! in kernel exception
+       mov     r15,r2
+       add     #-((OFF_TRA + 4) - OFF_PC) + 5*4,r15
+       movmu.l r3,@-r15
+       mov     r2,r8           ! r8 = previous stack top
+       mov     r1,r9           ! r9 = interrupt vector
+       ! restore exception frame & regs
+       mov.l   @r8+,r2         ! old R2
+       mov.l   @r8+,r0         ! old R0
+       mov.l   @r8+,r1         ! old R1
+       mov.l   @r8+,r10        ! old PC
+       mov.l   @r8+,r11        ! old SR
+       movml.l r2,@-r15
+       mov.l   r10,@(OFF_PC,r15)
+       mov.l   r11,@(OFF_SR,r15)
+       mov.l   r8,@(OFF_SP,r15)        ! save old sp
+       mov     r15,r8
+       add     #OFF_TRA + 4,r8
+       mov.l   r9,@-r8
+       sts.l   macl,@-r8
+       sts.l   mach,@-r8
+       stc.l   gbr,@-r8
+       add     #-4,r8
+       sts.l   pr,@-r8
+2:
+       ! dispatch exception / interrupt
+       mov     #64,r8
+       cmp/hs  r8,r9
+       bt      interrupt_entry ! vec >= 64 is interrupt
+       mov     #32,r8
+       cmp/hs  r8,r9
+       bt      trap_entry      ! 64 > vec >= 32  is trap
+
+       mov.l   4f,r8
+       mov     r9,r4
+       shll2   r9
+       add     r9,r8
+       mov.l   @r8,r8          ! exception handler address
+       tst     r8,r8
+       bf      3f
+       mov.l   8f,r8           ! unhandled exception
+3:
+       mov.l   5f,r10
+       jmp     @r8
+        lds    r10,pr
+
+interrupt_entry:
+       mov     r9,r4
+       mov     r15,r5
+       mov.l   7f,r8
+       mov.l   6f,r9
+       jmp     @r8
+        lds    r9,pr
+
+       .align  2
+4:     .long   exception_handling_table
+5:     .long   ret_from_exception
+6:     .long   ret_from_irq
+7:     .long   do_IRQ
+8:     .long   exception_error
+
+trap_entry:
+       mov     #0x30,r8
+       cmp/ge  r8,r9           ! vector 0x20-0x2f is systemcall
+       bt      1f
+       add     #-0x10,r9       ! convert SH2 to SH3/4 ABI
+1:     
+       shll2   r9                      ! TRA
+       bra     system_call     ! jump common systemcall entry
+        mov    r9,r8
+       
+#if defined(CONFIG_SH_STANDARD_BIOS)
+       /* Unwind the stack and jmp to the debug entry */
+ENTRY(sh_bios_handler)
+       mov     r15,r0
+       add     #(22-4)*4-4,r0
+       ldc.l   @r0+,gbr
+       lds.l   @r0+,mach
+       lds.l   @r0+,macl
+       mov     r15,r0
+       mov.l   @(OFF_SP,r0),r1
+       mov.l   @(OFF_SR,r2),r3
+       mov.l   r3,@-r1
+       mov.l   @(OFF_SP,r2),r3
+       mov.l   r3,@-r1
+       mov     r15,r0
+       add     #(22-4)*4-8,r0
+       mov.l   1f,r2
+       mov.l   @r2,r2
+       stc     sr,r3
+       mov.l   r2,@r0
+       mov.l   r3,@(4,r0)
+       mov.l   r1,@(8,r0)
+       movml.l @r15+,r14
+       add     #8,r15
+       lds.l   @r15+, pr
+       rte
+        mov.l  @r15+,r15
+       .align  2
+1:     .long   gdb_vbr_vector
+#endif /* CONFIG_SH_STANDARD_BIOS */
+
+ENTRY(address_error_trap_handler)
+       mov     r15,r4                          ! regs
+       mov.l   @(OFF_PC,r15),r6                ! pc
+       mov.l   1f,r0
+       jmp     @r0
+        mov    #0,r5                           ! writeaccess is unknown
+
+       .align  2
+1:     .long   do_address_error
+
+restore_all:
+       stc     sr,r0
+       or      #0xf0,r0
+       ldc     r0,sr                           ! all interrupt block (same BL = 1)
+       ! restore special register
+       ! overlap exception frame
+       mov     r15,r0
+       add     #17*4,r0
+       lds.l   @r0+,pr
+       add     #4,r0
+       ldc.l   @r0+,gbr
+       lds.l   @r0+,mach
+       lds.l   @r0+,macl
+       mov     r15,r0
+       mov.l   $cpu_mode,r2
+       bld.b   #6,@(OFF_SR,r15)
+       bst.b   #6,@(0,r2)                      ! save CPU mode
+       mov.l   @(OFF_SR,r0),r1
+       shll2   r1
+       shlr2   r1                              ! clear MD bit
+       mov.l   @(OFF_SP,r0),r2
+       add     #-8,r2
+       mov.l   r2,@(OFF_SP,r0)                 ! point exception frame top
+       mov.l   r1,@(4,r2)                      ! set sr
+       mov.l   @(OFF_PC,r0),r1
+       mov.l   r1,@r2                          ! set pc
+       get_current_thread_info r0, r1
+       mov.l   $current_thread_info,r1
+       mov.l   r0,@r1
+       movml.l @r15+,r14
+       mov.l   @r15,r15
+       rte
+        nop
+
+       .align 2
+$current_thread_info:
+       .long   __current_thread_info
+$cpu_mode:     
+       .long   __cpu_mode
+               
+! common exception handler
+#include "../../entry-common.S"
+       
+       .data
+! cpu operation mode 
+! bit30 = MD (compatible SH3/4)
+__cpu_mode:
+       .long   0x40000000
+               
+       .section        .bss
+__current_thread_info:
+       .long   0
+
+ENTRY(exception_handling_table)
+       .space  4*32

diff --git a/arch/sh/kernel/cpu/sh2a/ex.S b/arch/sh/kernel/cpu/sh2a/ex.S
new file mode 100644 (file)
index 0000000..3ead9e6
--- /dev/null
+++ b/arch/sh/kernel/cpu/sh2a/ex.S
@@ -0,0 +1,72 @@
+/*
+ * arch/sh/kernel/cpu/sh2a/ex.S
+ *
+ * The SH-2A exception vector table
+ *
+ * Copyright (C) 2008 Yoshinori Sato
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <linux/linkage.h>
+
+!
+! convert Exception Vector to Exception Number
+!
+
+! exception no 0 to 255
+exception_entry0:
+no     =       0
+       .rept   256
+       mov.l   r1,@-sp
+       bra     exception_trampoline0
+       mov     #no,r1
+no     =       no + 1
+       .endr
+exception_trampoline0:
+       mov.l   r0,@-sp
+       mov.l   1f,r0
+       extu.b  r1,r1
+       jmp     @r0
+         extu.w        r1,r1
+        
+       .align  2
+1:     .long   exception_handler
+
+! exception no 256 to 511
+exception_entry1:
+no     =       0
+       .rept   256
+       mov.l   r1,@-sp
+       bra     exception_trampoline1
+       mov     #no,r1
+no     =       no + 1
+       .endr
+exception_trampoline1:
+       mov.l   r0,@-sp
+       extu.b  r1,r1
+       movi20  #0x100,r0
+       add     r0,r1
+       mov.l   1f,r0
+       jmp     @r0
+         extu.w        r1,r1
+       
+       .align  2
+1:     .long   exception_handler
+
+       !
+! Exception Vector Base
+!
+       .align  2
+ENTRY(vbr_base)
+vector =       0
+       .rept   256
+       .long   exception_entry0 + vector * 6
+vector =       vector + 1
+       .endr
+       .rept   256
+       .long   exception_entry1 + vector * 6
+vector =       vector + 1
+       .endr

diff --git a/arch/sh/kernel/traps_32.c b/arch/sh/kernel/traps_32.c
index e08b3bf..511a942 100644 (file)
--- a/arch/sh/kernel/traps_32.c
+++ b/arch/sh/kernel/traps_32.c
@@ -43,6 +43,7 @@
 # define TRAP_ILLEGAL_SLOT_INST        6
 # define TRAP_ADDRESS_ERROR    9
 # ifdef CONFIG_CPU_SH2A
+#  define TRAP_FPU_ERROR       13
 #  define TRAP_DIVZERO_ERROR   17
 #  define TRAP_DIVOVF_ERROR    18
 # endif
@@ -851,6 +852,9 @@ void __init trap_init(void)
 #ifdef CONFIG_CPU_SH2A
        set_exception_table_vec(TRAP_DIVZERO_ERROR, do_divide_error);
        set_exception_table_vec(TRAP_DIVOVF_ERROR, do_divide_error);
+#ifdef CONFIG_SH_FPU
+       set_exception_table_vec(TRAP_FPU_ERROR, fpu_error_trap_handler);
+#endif
 #endif
 
        /* Setup VBR for boot cpu */