/*
* linux/arch/unicore32/kernel/entry.S
*
* Code specific to PKUnity SoC and UniCore ISA
*
* Copyright (C) 2001-2010 GUAN Xue-tao
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Low-level vector interface routines
*/
#include <linux/init.h>
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/errno.h>
#include <asm/thread_info.h>
#include <asm/memory.h>
#include <asm/unistd.h>
#include <generated/asm-offsets.h>
#include "debug-macro.S"
@
@ Most of the stack format comes from struct pt_regs, but with
@ the addition of 8 bytes for storing syscall args 5 and 6.
@
#define S_OFF 8
/*
* The SWI code relies on the fact that R0 is at the bottom of the stack
* (due to slow/fast restore user regs).
*/
#if S_R0 != 0
#error "Please fix"
#endif
.macro zero_fp
#ifdef CONFIG_FRAME_POINTER
mov fp, #0
#endif
.endm
.macro alignment_trap, rtemp
#ifdef CONFIG_ALIGNMENT_TRAP
ldw \rtemp, .LCcralign
ldw \rtemp, [\rtemp]
movc p0.c1, \rtemp, #0
#endif
.endm
.macro load_user_sp_lr, rd, rtemp, offset = 0
mov \rtemp, asr
xor \rtemp, \rtemp, #(PRIV_MODE ^ SUSR_MODE)
mov.a asr, \rtemp @ switch to the SUSR mode
ldw sp, [\rd+], #\offset @ load sp_user
ldw lr, [\rd+], #\offset + 4 @ load lr_user
xor \rtemp, \rtemp, #(PRIV_MODE ^ SUSR_MODE)
mov.a asr, \rtemp @ switch back to the PRIV mode
.endm
.macro priv_exit, rpsr
mov.a bsr, \rpsr
ldm.w (r0 - r15), [sp]+
ldm.b (r16 - pc), [sp]+ @ load r0 - pc, asr
.endm
.macro restore_user_regs, fast = 0, offset = 0
ldw r1, [sp+], #\offset + S_PSR @ get calling asr
ldw lr, [sp+], #\offset + S_PC @ get pc
mov.a bsr, r1 @ save in bsr_priv
.if \fast
add sp, sp, #\offset + S_R1 @ r0 is syscall return value
ldm.w (r1 - r15), [sp]+ @ get calling r1 - r15
ldur (r16 - lr), [sp]+ @ get calling r16 - lr
.else
ldm.w (r0 - r15), [sp]+ @ get calling r0 - r15
ldur (r16 - lr), [sp]+ @ get calling r16 - lr
.endif
nop
add sp, sp, #S_FRAME_SIZE - S_R16
mov.a pc, lr @ return
@ and move bsr_priv into asr
.endm
.macro get_thread_info, rd
mov \rd, sp >> #13
mov \rd, \rd << #13
.endm
.macro get_irqnr_and_base, irqnr, irqstat, base, tmp
ldw \base, =(PKUNITY_INTC_BASE)
ldw \irqstat, [\base+], #0xC @ INTC_ICIP
ldw \tmp, [\base+], #0x4 @ INTC_ICMR
and.a \irqstat, \irqstat, \tmp
beq 1001f
cntlz \irqnr, \irqstat
rsub \irqnr, \irqnr, #31
1001: /* EQ will be set if no irqs pending */
.endm
#ifdef CONFIG_DEBUG_LL
.macro printreg, reg, temp
adr \temp, 901f
stm (r0-r3), [\temp]+
stw lr, [\temp+], #0x10
mov r0, \reg
b.l printhex8
mov r0, #':'
b.l printch
mov r0, pc
b.l printhex8
adr r0, 902f
b.l printascii
adr \temp, 901f
ldm (r0-r3), [\temp]+
ldw lr, [\temp+], #0x10
b 903f
901: .word 0, 0, 0, 0, 0 @ r0-r3, lr
902: .asciz ": epip4d\n"
.align
903:
.endm
#endif
/*
* These are the registers used in the syscall handler, and allow us to
* have in theory up to 7 arguments to a function - r0 to r6.
*
* Note that tbl == why is intentional.
*
* We must set at least "tsk" and "why" when calling ret_with_reschedule.
*/
scno .req r21 @ syscall number
tbl .req r22 @ syscall table pointer
why .req r22 @ Linux syscall (!= 0)
tsk .req r23 @ current thread_info
/*
* Interrupt handling. Preserves r17, r18, r19
*/
.macro intr_handler
1: get_irqnr_and_base r0, r6, r5, lr
beq 2f
mov r1, sp
@
@ routine called with r0 = irq number, r1 = struct pt_regs *
@
adr lr, 1b
b asm_do_IRQ
2:
.endm
/*
* PRIV mode handlers
*/
.macro priv_entry
sub sp, sp, #(S_FRAME_SIZE - 4)
stm (r1 - r15), [sp]+
add r5, sp, #S_R15
stm (r16 - r28), [r5]+
ldm (r1 - r3), [r0]+