linux/arch/mips/kernel/head.S
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00

222 lines
5.4 KiB
ArmAsm

/*
* 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) 1994, 1995 Waldorf Electronics
* Written by Ralf Baechle and Andreas Busse
* Copyright (C) 1994, 95, 96, 97, 98, 99, 2003 Ralf Baechle
* Copyright (C) 1996 Paul M. Antoine
* Modified for DECStation and hence R3000 support by Paul M. Antoine
* Further modifications by David S. Miller and Harald Koerfgen
* Copyright (C) 1999 Silicon Graphics, Inc.
* Kevin Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
* Copyright (C) 2000 MIPS Technologies, Inc. All rights reserved.
*/
#include <linux/config.h>
#include <linux/init.h>
#include <linux/threads.h>
#include <asm/asm.h>
#include <asm/regdef.h>
#include <asm/page.h>
#include <asm/mipsregs.h>
#include <asm/stackframe.h>
#ifdef CONFIG_SGI_IP27
#include <asm/sn/addrs.h>
#include <asm/sn/sn0/hubni.h>
#include <asm/sn/klkernvars.h>
#endif
.macro ARC64_TWIDDLE_PC
#if defined(CONFIG_ARC64) || defined(CONFIG_MAPPED_KERNEL)
/* We get launched at a XKPHYS address but the kernel is linked to
run at a KSEG0 address, so jump there. */
PTR_LA t0, \@f
jr t0
\@:
#endif
.endm
#ifdef CONFIG_SGI_IP27
/*
* outputs the local nasid into res. IP27 stuff.
*/
.macro GET_NASID_ASM res
dli \res, LOCAL_HUB_ADDR(NI_STATUS_REV_ID)
ld \res, (\res)
and \res, NSRI_NODEID_MASK
dsrl \res, NSRI_NODEID_SHFT
.endm
#endif /* CONFIG_SGI_IP27 */
/*
* inputs are the text nasid in t1, data nasid in t2.
*/
.macro MAPPED_KERNEL_SETUP_TLB
#ifdef CONFIG_MAPPED_KERNEL
/*
* This needs to read the nasid - assume 0 for now.
* Drop in 0xffffffffc0000000 in tlbhi, 0+VG in tlblo_0,
* 0+DVG in tlblo_1.
*/
dli t0, 0xffffffffc0000000
dmtc0 t0, CP0_ENTRYHI
li t0, 0x1c000 # Offset of text into node memory
dsll t1, NASID_SHFT # Shift text nasid into place
dsll t2, NASID_SHFT # Same for data nasid
or t1, t1, t0 # Physical load address of kernel text
or t2, t2, t0 # Physical load address of kernel data
dsrl t1, 12 # 4K pfn
dsrl t2, 12 # 4K pfn
dsll t1, 6 # Get pfn into place
dsll t2, 6 # Get pfn into place
li t0, ((_PAGE_GLOBAL|_PAGE_VALID| _CACHE_CACHABLE_COW) >> 6)
or t0, t0, t1
mtc0 t0, CP0_ENTRYLO0 # physaddr, VG, cach exlwr
li t0, ((_PAGE_GLOBAL|_PAGE_VALID| _PAGE_DIRTY|_CACHE_CACHABLE_COW) >> 6)
or t0, t0, t2
mtc0 t0, CP0_ENTRYLO1 # physaddr, DVG, cach exlwr
li t0, 0x1ffe000 # MAPPED_KERN_TLBMASK, TLBPGMASK_16M
mtc0 t0, CP0_PAGEMASK
li t0, 0 # KMAP_INX
mtc0 t0, CP0_INDEX
li t0, 1
mtc0 t0, CP0_WIRED
tlbwi
#else
mtc0 zero, CP0_WIRED
#endif
.endm
/*
* For the moment disable interrupts, mark the kernel mode and
* set ST0_KX so that the CPU does not spit fire when using
* 64-bit addresses. A full initialization of the CPU's status
* register is done later in per_cpu_trap_init().
*/
.macro setup_c0_status set clr
.set push
mfc0 t0, CP0_STATUS
or t0, ST0_CU0|\set|0x1f|\clr
xor t0, 0x1f|\clr
mtc0 t0, CP0_STATUS
.set noreorder
sll zero,3 # ehb
.set pop
.endm
.macro setup_c0_status_pri
#ifdef CONFIG_MIPS64
setup_c0_status ST0_KX 0
#else
setup_c0_status 0 0
#endif
.endm
.macro setup_c0_status_sec
#ifdef CONFIG_MIPS64
setup_c0_status ST0_KX ST0_BEV
#else
setup_c0_status 0 ST0_BEV
#endif
.endm
/*
* Reserved space for exception handlers.
* Necessary for machines which link their kernels at KSEG0.
*/
.fill 0x400
EXPORT(stext) # used for profiling
EXPORT(_stext)
__INIT
NESTED(kernel_entry, 16, sp) # kernel entry point
setup_c0_status_pri
#ifdef CONFIG_SGI_IP27
GET_NASID_ASM t1
move t2, t1 # text and data are here
MAPPED_KERNEL_SETUP_TLB
#endif /* IP27 */
ARC64_TWIDDLE_PC
PTR_LA t0, __bss_start # clear .bss
LONG_S zero, (t0)
PTR_LA t1, __bss_stop - LONGSIZE
1:
PTR_ADDIU t0, LONGSIZE
LONG_S zero, (t0)
bne t0, t1, 1b
LONG_S a0, fw_arg0 # firmware arguments
LONG_S a1, fw_arg1
LONG_S a2, fw_arg2
LONG_S a3, fw_arg3
PTR_LA $28, init_thread_union
PTR_ADDIU sp, $28, _THREAD_SIZE - 32
set_saved_sp sp, t0, t1
PTR_SUBU sp, 4 * SZREG # init stack pointer
j start_kernel
END(kernel_entry)
#ifdef CONFIG_SMP
/*
* SMP slave cpus entry point. Board specific code for bootstrap calls this
* function after setting up the stack and gp registers.
*/
NESTED(smp_bootstrap, 16, sp)
setup_c0_status_sec
#ifdef CONFIG_SGI_IP27
GET_NASID_ASM t1
dli t0, KLDIR_OFFSET + (KLI_KERN_VARS * KLDIR_ENT_SIZE) + \
KLDIR_OFF_POINTER + CAC_BASE
dsll t1, NASID_SHFT
or t0, t0, t1
ld t0, 0(t0) # t0 points to kern_vars struct
lh t1, KV_RO_NASID_OFFSET(t0)
lh t2, KV_RW_NASID_OFFSET(t0)
MAPPED_KERNEL_SETUP_TLB
ARC64_TWIDDLE_PC
#endif /* CONFIG_SGI_IP27 */
j start_secondary
END(smp_bootstrap)
#endif /* CONFIG_SMP */
__FINIT
.comm kernelsp, NR_CPUS * 8, 8
.comm pgd_current, NR_CPUS * 8, 8
.comm fw_arg0, SZREG, SZREG # firmware arguments
.comm fw_arg1, SZREG, SZREG
.comm fw_arg2, SZREG, SZREG
.comm fw_arg3, SZREG, SZREG
.macro page name, order=0
.globl \name
\name: .size \name, (_PAGE_SIZE << \order)
.org . + (_PAGE_SIZE << \order)
.type \name, @object
.endm
.data
.align PAGE_SHIFT
/*
* ... but on 64-bit we've got three-level pagetables with a
* slightly different layout ...
*/
page swapper_pg_dir, _PGD_ORDER
#ifdef CONFIG_MIPS64
page invalid_pmd_table, _PMD_ORDER
#endif
page invalid_pte_table, _PTE_ORDER