u-boot/arch/mips/mach-octeon/lowlevel_init.S
Stefan Roese 7c6f274a36 mips: octeon: lowlevel_init.S: Add NMI handling code for SMP Linux booting
This patch adds the necessary lowlevel init code, to enable SMP Linux
booting. This code will be used with the platform specific Octeon Linux
boot command "bootoctlinux", which starts a configurable number of cores
into Linux.

Additionally some erratas and lowlevel register initializations are
copied from the original Cavium / Marvell U-Boot source code, enabling
booting into the Linux kernel.

Signed-off-by: Stefan Roese <sr@denx.de>
2020-10-07 20:25:57 +02:00

145 lines
3.1 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2020 Stefan Roese <sr@denx.de>
*/
#include <config.h>
#include <asm-offsets.h>
#include <asm/cacheops.h>
#include <asm/regdef.h>
#include <asm/mipsregs.h>
#include <asm/addrspace.h>
#include <asm/asm.h>
#include <mach/octeon-model.h>
#define COP0_CVMCTL_REG $9,7 /* Cavium control */
#define COP0_CVMMEMCTL_REG $11,7 /* Cavium memory control */
#define COP0_PROC_ID_REG $15,0
.set noreorder
LEAF(lowlevel_init)
/* Set LMEMSZ in CVMMEMCTL register */
dmfc0 a0, COP0_CVMMEMCTL_REG
dins a0, zero, 0, 9
mfc0 a4, COP0_PROC_ID_REG
li a5, OCTEON_CN63XX_PASS1_0 /* Octeon cn63xx pass1 chip id */
bgt a5, a4, 2f
ori a0, 0x104 /* setup 4 lines of scratch */
ori a6, a5, 8 /* Octeon cn63xx pass2 chip id */
bge a4, a6, 2f
nop
li a6, 4
ins a0, a6, 11, 4 /* Set WBTHRESH=4 as per Core-14752 errata */
2:
dmtc0 a0, COP0_CVMMEMCTL_REG
/* Set REPUN bit in CVMCTL register */
dmfc0 a0, COP0_CVMCTL_REG
ori a0, 1<<14 /* enable fixup of unaligned mem access */
dmtc0 a0, COP0_CVMCTL_REG
jr ra
nop
END(lowlevel_init)
LEAF(mips_mach_early_init)
move s0, ra
bal __dummy
nop
__dummy:
/* Get the actual address that we are running at */
PTR_LA a7, __dummy
dsubu t3, ra, a7 /* t3 now has reloc offset */
PTR_LA t1, _start
daddu t0, t1, t3 /* t0 now has actual address of _start */
/* Calculate end address of copy loop */
PTR_LA t2, _end
daddiu t2, t2, 0x4000 /* Increase size to include appended DTB */
daddiu t2, t2, 127
ins t2, zero, 0, 7 /* Round up to cache line for memcpy */
/* Copy ourself to the L2 cache from flash, 32 bytes at a time */
1:
ld a0, 0(t0)
ld a1, 8(t0)
ld a2, 16(t0)
ld a3, 24(t0)
sd a0, 0(t1)
sd a1, 8(t1)
sd a2, 16(t1)
sd a3, 24(t1)
addiu t0, 32
addiu t1, 32
bne t1, t2, 1b
nop
sync
/*
* Return to start.S now running from TEXT_BASE, which points
* to DRAM address space, which effectively is L2 cache now.
* This speeds up the init process extremely, especially the
* DDR init code.
*/
dsubu s0, s0, t3 /* Fixup return address with reloc offset */
jr.hb s0 /* Jump back with hazard barrier */
nop
END(mips_mach_early_init)
LEAF(nmi_bootvector)
/*
* From Marvell original bootvector setup
*/
mfc0 k0, CP0_STATUS
/* Enable 64-bit addressing, set ERL (should already be set) */
ori k0, 0x84
mtc0 k0, CP0_STATUS
/* Core-14345, clear L1 Dcache virtual tags if the core hit an NMI */
cache 17, 0($0)
/*
* Needed for Linux kernel booting, otherwise it hangs while
* zero'ing all of CVMSEG
*/
dmfc0 a0, COP0_CVMMEMCTL_REG
dins a0, zero, 0, 9
ori a0, 0x104 /* setup 4 lines of scratch */
dmtc0 a0, COP0_CVMMEMCTL_REG
/*
* Load parameters and entry point
*/
PTR_LA t9, nmi_handler_para
sync
ld s0, 0x00(t9)
ld a0, 0x08(t9)
ld a1, 0x10(t9)
ld a2, 0x18(t9)
ld a3, 0x20(t9)
/* Finally jump to entry point (start kernel etc) */
j s0
nop
END(nmi_bootvector)
/*
* Add here some space for the NMI parameters (entry point and args)
*/
.globl nmi_handler_para
nmi_handler_para:
.dword 0 // entry-point
.dword 0 // arg0
.dword 0 // arg1
.dword 0 // arg2
.dword 0 // arg3