/*
* 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.
*
* Copyright (C) 2011 by Kevin Cernekee (cernekee@gmail.com)
*
* Reset/NMI/re-entry vectors for BMIPS processors
*/
#include <asm/asm.h>
#include <asm/asmmacro.h>
#include <asm/cacheops.h>
#include <asm/cpu.h>
#include <asm/regdef.h>
#include <asm/mipsregs.h>
#include <asm/stackframe.h>
#include <asm/addrspace.h>
#include <asm/hazards.h>
#include <asm/bmips.h>
.macro BARRIER
.set mips32
_ssnop
_ssnop
_ssnop
.set mips0
.endm
/***********************************************************************
* Alternate CPU1 startup vector for BMIPS4350
*
* On some systems the bootloader has already started CPU1 and configured
* it to resume execution at 0x8000_0200 (!BEV IV vector) when it is
* triggered by the SW1 interrupt. If that is the case we try to move
* it to a more convenient place: BMIPS_WARM_RESTART_VEC @ 0x8000_0380.
***********************************************************************/
LEAF(bmips_smp_movevec)
la k0, 1f
li k1, CKSEG1
or k0, k1
jr k0
1:
/* clear IV, pending IPIs */
mtc0 zero, CP0_CAUSE
/* re-enable IRQs to wait for SW1 */
li k0, ST0_IE | ST0_BEV | STATUSF_IP1
mtc0 k0, CP0_STATUS
/* set up CPU1 CBR; move BASE to 0xa000_0000 */
li k0, 0xff400000
mtc0 k0, $22, 6
/* set up relocation vector address based on thread ID */
mfc0 k1, $22, 3
srl k1, 16
andi k1, 0x8000
or k1, CKSEG1 | BMIPS_RELO_VECTOR_CONTROL_0
or k0, k1
li k1, 0xa0080000
sw k1, 0(k0)
/* wait here for SW1 interrupt from bmips_boot_secondary() */
wait
la k0, bmips_reset_nmi_vec
li k1, CKSEG1
or k0, k1
jr k0
END(bmips_smp_movevec)
/***********************************************************************
* Reset/NMI vector
* For BMIPS processors that can relocate their exception vectors, this
* entire function gets copied to 0x8000_0000.
***********************************************************************/
NESTED(bmips_reset_nmi_vec, PT_SIZE, sp)
.set push
.set noat
.align 4
#ifdef CONFIG_SMP
/* if the NMI bit is clear, assume this is a CPU1 reset instead */
li k1, (1 << 19)
mfc0 k0, CP0_STATUS
and k0, k1
beqz k0, soft_reset
#if defined(CONFIG_CPU_BMIPS5000)
mfc0 k0, CP0_PRID
li k1, PRID_IMP_BMIPS5000
/* mask with PRID_IMP_BMIPS5000 to cover both variants */
andi k0, PRID_IMP_BMIPS5000
bne k0, k1, 1f
/* if we're not on core 0, this must be the SMP boot signal */
li k1, (3 << 25)
mfc0 k0, $22
and k0, k1
bnez k0, bmips_smp_entry
1:
#endif /* CONFIG_CPU_BMIPS5000 */
#endif /* CONFIG_SMP */
/* nope, it's just a regular NMI */
SAVE_ALL
move a0, sp
/* clear EXL, ERL, BEV so that TLB refills still work */
mfc0 k0, CP0_STATUS
li k1, ST0_ERL | ST0_EXL | ST0_BEV | ST0_IE
or k0, k1
xor k0, k1
mtc0 k0, CP0_STATUS
BARRIER
/* jump to the NMI handler function */
la k0, nmi_handler
jr k0
RESTORE_ALL
.set arch=r4000
eret
#ifdef CONFIG_SMP
soft_reset:
#if defined(CONFIG_CPU_BMIPS5000)
mfc0 k0, CP0_PRID
andi k0, 0xff00
li k1, PRID_IMP_BMIPS5200
bne k0, k1, bmips_smp_entry
/* if running on TP 1, jump to bmips_smp_entry */
mfc0 k0, $22
li k1, (1 << 24)
and k1, k0
bnez k1, bmips_smp_entry
nop
/*
* running on TP0, can not be core 0 (the boot core).
* Check for soft reset. Indicates a warm boot
*/
mfc0 k0, $12
li k1, (1 << 20)
and k0, k1
beqz k0, bmips_smp_entry
/*
* Warm boot.
* Cache init is only done on TP0
*/
la k0, bmips_5xxx_init
jalr k0
nop
b bmips_smp_entry
nop
#endif
/***********************************************************************
* CPU1 reset vector (used for the initial boot only)
* This is still part of bmips_reset_nmi_vec().
***********************************************************************/
bmips_smp_entry:
/* set up CP0 STATUS; enable FPU */
li k0, 0x30000000
mtc0 k0, CP0_STATUS
BARRIER
/* set local CP0 CONFIG to make kseg0 cacheable, write-back */
mfc0 k0, CP0_CONFIG
ori k0, 0x07
xori k0, 0x04
mtc0 k0, CP0_CONFIG
mfc0 k0, CP0_PRID
andi k0, 0xff00
#if defined(CONFIG_CPU_BMIPS4350) || defined(CONFIG_CPU_BMIPS4380)
li k1, PRID_IMP_BMIPS43XX
bne k0, k1, 2f
/* initialize CPU1's local I-cache */
li k0, 0x80000000
li k1, 0x80010000
mtc0 zero, $28
mtc0 zero, $28, 1
BARRIER
1: cache Index_Store_Tag_I, 0(k0)
addiu k0, 16
bne k0, k1, 1b
b 3f
2:
#endif /* CONFIG_CPU_BMIPS4350 || CONFIG_CPU_BMIPS4380 */
#if defined(CONFIG_CPU_BMIPS5000)
/* mask with PRID_IMP_BMIPS5000 to cover both variants */
li k1, PRID_IMP_BMIPS5000
andi k0, PRID_IMP_BMIPS5000
bne k0, k1, 3f
/* set exception vector base */
la k0, ebase
lw k0, 0(k0)
mtc0 k0, $15, 1
BARRIER
#endif /* CONFIG_CPU_BMIPS5000 */
3:
/* jump back to kseg0 in case we need to remap the kseg1 area */
la k0, 1f
jr k0
1:
la k0, bmips_enable_xks01
jalr k0
/* use temporary stack to set up upper memory TLB */
li sp, BMIPS_WARM_RESTART_VEC
la k0, plat_wired_tlb_setup
jalr k0
/* switch to permanent stack and continue booting */
.global bmips_secondary_reentry
bmips_secondary_reentry:
la k0, bmips_smp_boot_sp
lw sp, 0(k0)
la k0, bmips_smp_boot_gp
lw gp, 0(k0)
la k0, start_secondary
jr k0
#endif /* CONFIG_SMP */
.align 4
.global bmips_reset_nmi_vec_end
bmips_reset_nmi_vec_end:
END(bmips_reset_nmi_vec)
.set pop
/***********************************************************************
* CPU1 warm restart vector (used for second and subsequent boots).
* Also used for S2 standby recovery (PM).
* This entire function gets copied to (BMIPS_WARM_RESTART_VEC)
***********************************************************************/
LEAF(bmips_smp_int_vec)
.align 4
mfc0 k0, CP0_STATUS
ori k0, 0x01
xori k0, 0x01
mtc0 k0, CP0_STATUS
eret
.align 4
.global bmips_smp_int_vec_end
bmips_smp_int_vec_end:
END(bmips_smp_int_vec)
/***********************************************************************
* XKS01 support
* Certain CPUs support extending kseg0 to 1024MB.
***********************************************************************/
LEAF(bmips_enable_xks01)
#if defined(CONFIG_XKS01)
mfc0 t0, CP0_PRID
andi t2, t0, 0xff00
#if defined(CONFIG_CPU_BMIPS4380)
li t1, PRID_IMP_BMIPS43XX
bne t2, t1, 1f
andi t0, 0xff
addiu t1, t0, -PRID_REV_BMIPS4380_HI
bgtz t1, 2f
addiu t0, -PRID_REV_BMIPS4380_LO
bltz t0, 2f
mfc0 t0, $22, 3
li t1, 0x1ff0
li t2, (1 << 12) | (1 << 9)
or t0, t1
xor t0, t1
or t0, t2
mtc0 t0, $22, 3
BARRIER
b 2f
1:
#endif /* CONFIG_CPU_BMIPS4380 */
#if defined(CONFIG_CPU_BMIPS5000)
li t1, PRID_IMP_BMIPS5000
/* mask with PRID_IMP_BMIPS5000 to cover both variants */
andi t2, PRID_IMP_BMIPS5000
bne t2, t1, 2f
mfc0 t0, $22, 5
li t1, 0x01ff
li t2, (1 << 8) | (1 << 5)
or t0, t1
xor t0, t1
or t0, t2
mtc0 t0, $22, 5
BARRIER
#endif /* CONFIG_CPU_BMIPS5000 */
2:
#endif /* defined(CONFIG_XKS01) */
jr ra
END(bmips_enable_xks01)