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Diffstat (limited to 'arch/mips/kernel/head.S')
| -rw-r--r-- | arch/mips/kernel/head.S | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/arch/mips/kernel/head.S b/arch/mips/kernel/head.S new file mode 100644 index 00000000000..a64e87d2201 --- /dev/null +++ b/arch/mips/kernel/head.S @@ -0,0 +1,221 @@ +/* + * 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 |