linux/arch/nds32/kernel/ex-entry.S
Vincent Chen e46bf83c18 nds32: nds32 FPU port
This patch set contains basic components for supporting the nds32 FPU,
such as exception handlers and context switch for FPU registers. By
default, the lazy FPU scheme is supported and the user can configure it via
CONFIG_LZAY_FPU.

Signed-off-by: Vincent Chen <vincentc@andestech.com>
Acked-by: Greentime Hu <greentime@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>
2018-11-22 18:13:13 +08:00

178 lines
3.8 KiB
ArmAsm

// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2005-2017 Andes Technology Corporation
#include <linux/linkage.h>
#include <asm/memory.h>
#include <asm/nds32.h>
#include <asm/errno.h>
#include <asm/asm-offsets.h>
#include <asm/page.h>
#include <asm/fpu.h>
#ifdef CONFIG_HWZOL
.macro push_zol
mfusr $r14, $LB
mfusr $r15, $LE
mfusr $r16, $LC
.endm
#endif
.macro skip_save_fucop_ctl
#if defined(CONFIG_FPU)
skip_fucop_ctl:
smw.adm $p0, [$sp], $p0, #0x1
j fucop_ctl_done
#endif
.endm
.macro save_user_regs
#if defined(CONFIG_FPU)
sethi $p0, hi20(has_fpu)
lbsi $p0, [$p0+lo12(has_fpu)]
beqz $p0, skip_fucop_ctl
mfsr $p0, $FUCOP_CTL
smw.adm $p0, [$sp], $p0, #0x1
bclr $p0, $p0, #FUCOP_CTL_offCP0EN
mtsr $p0, $FUCOP_CTL
fucop_ctl_done:
/* move $SP to the bottom of pt_regs */
addi $sp, $sp, -FUCOP_CTL_OFFSET
#else
smw.adm $sp, [$sp], $sp, #0x1
/* move $SP to the bottom of pt_regs */
addi $sp, $sp, -OSP_OFFSET
#endif
/* push $r0 ~ $r25 */
smw.bim $r0, [$sp], $r25
/* push $fp, $gp, $lp */
smw.bim $sp, [$sp], $sp, #0xe
mfsr $r12, $SP_USR
mfsr $r13, $IPC
#ifdef CONFIG_HWZOL
push_zol
#endif
movi $r17, -1
move $r18, $r0
mfsr $r19, $PSW
mfsr $r20, $IPSW
mfsr $r21, $P_IPSW
mfsr $r22, $P_IPC
mfsr $r23, $P_P0
mfsr $r24, $P_P1
smw.bim $r12, [$sp], $r24, #0
addi $sp, $sp, -FUCOP_CTL_OFFSET
/* Initialize kernel space $fp */
andi $p0, $r20, #PSW_mskPOM
movi $p1, #0x0
cmovz $fp, $p1, $p0
andi $r16, $r19, #PSW_mskINTL
slti $r17, $r16, #4
bnez $r17, 1f
addi $r17, $r19, #-2
mtsr $r17, $PSW
isb
1:
/* If it was superuser mode, we don't need to update $r25 */
bnez $p0, 2f
la $p0, __entry_task
lw $r25, [$p0]
2:
.endm
.text
/*
* Exception Vector
*/
exception_handlers:
.long unhandled_exceptions !Reset/NMI
.long unhandled_exceptions !TLB fill
.long do_page_fault !PTE not present
.long do_dispatch_tlb_misc !TLB misc
.long unhandled_exceptions !TLB VLPT
.long unhandled_exceptions !Machine Error
.long do_debug_trap !Debug related
.long do_dispatch_general !General exception
.long eh_syscall !Syscall
.long asm_do_IRQ !IRQ
skip_save_fucop_ctl
common_exception_handler:
save_user_regs
mfsr $p0, $ITYPE
andi $p0, $p0, #ITYPE_mskVECTOR
srli $p0, $p0, #ITYPE_offVECTOR
andi $p1, $p0, #NDS32_VECTOR_mskNONEXCEPTION
bnez $p1, 1f
sethi $lp, hi20(ret_from_exception)
ori $lp, $lp, lo12(ret_from_exception)
sethi $p1, hi20(exception_handlers)
ori $p1, $p1, lo12(exception_handlers)
lw $p1, [$p1+$p0<<2]
move $r0, $p0
mfsr $r1, $EVA
mfsr $r2, $ITYPE
move $r3, $sp
mfsr $r4, $OIPC
/* enable gie if it is enabled in IPSW. */
mfsr $r21, $PSW
andi $r20, $r20, #PSW_mskGIE /* r20 is $IPSW*/
or $r21, $r21, $r20
mtsr $r21, $PSW
dsb
jr $p1
/* syscall */
1:
addi $p1, $p0, #-NDS32_VECTOR_offEXCEPTION
bnez $p1, 2f
sethi $lp, hi20(ret_from_exception)
ori $lp, $lp, lo12(ret_from_exception)
sethi $p1, hi20(exception_handlers)
ori $p1, $p1, lo12(exception_handlers)
lwi $p1, [$p1+#NDS32_VECTOR_offEXCEPTION<<2]
jr $p1
/* interrupt */
2:
#ifdef CONFIG_TRACE_IRQFLAGS
jal __trace_hardirqs_off
#endif
move $r0, $sp
sethi $lp, hi20(ret_from_intr)
ori $lp, $lp, lo12(ret_from_intr)
sethi $p0, hi20(exception_handlers)
ori $p0, $p0, lo12(exception_handlers)
lwi $p0, [$p0+#NDS32_VECTOR_offINTERRUPT<<2]
jr $p0
.macro EXCEPTION_VECTOR_DEBUG
.align 4
mfsr $p0, $EDM_CTL
andi $p0, $p0, EDM_CTL_mskV3_EDM_MODE
tnez $p0, SWID_RAISE_INTERRUPT_LEVEL
.endm
.macro EXCEPTION_VECTOR
.align 4
sethi $p0, hi20(common_exception_handler)
ori $p0, $p0, lo12(common_exception_handler)
jral.ton $p0, $p0
.endm
.section ".text.init", #alloc, #execinstr
.global exception_vector
exception_vector:
.rept 6
EXCEPTION_VECTOR
.endr
EXCEPTION_VECTOR_DEBUG
.rept 121
EXCEPTION_VECTOR
.endr
.align 4
.global exception_vector_end
exception_vector_end: