File-copy from v4.4.100
This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Please refer to that tree for all history prior to this point.
Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/arch/sh/kernel/cpu/sh2a/entry.S b/arch/sh/kernel/cpu/sh2a/entry.S
new file mode 100644
index 0000000..222742d
--- /dev/null
+++ b/arch/sh/kernel/cpu/sh2a/entry.S
@@ -0,0 +1,250 @@
+/*
+ * 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 <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
+ mov.l @r15+,r15
+ rte
+ nop
+ .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