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/*

 * 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.

 *

 * Head.S contains the MIPS exception handler and startup code.

 *

 * Copyright (C) 1994, 1995 Waldorf Electronics

 * Written by Ralf Baechle and Andreas Busse

 * Copyright (C) 1994, 1995, 1996, 1997, 1998, 1999 Ralf Baechle

 * Copyright (C) 1999 Silicon Graphics, Inc.

 */

#include 

#include 

#include 

#include 

#include 

#include 

#include 

#include 

#include 

#include 

#include 

        .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

        .text

EXPORT(stext)                                   # used for profiling

EXPORT(_stext)

        __INIT

NESTED(kernel_entry, 16, sp)                    # kernel entry point

        ori     sp, 0xf                         # align stack on 16 byte.

        xori    sp, 0xf

#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

        CLI                                     # disable interrupts

        /*

         * The firmware/bootloader passes argc/argp/envp

         * to us as arguments.  But clear bss first because

         * the romvec and other important info is stored there

         * by prom_init().

         */

        PTR_LA  t0, _edata

        sd      zero, (t0)

        PTR_LA  t1, (_end - 8)

1:

        daddiu  t0, 8

        sd      zero, (t0)

        bne     t0, t1, 1b

        PTR_LA  $28, init_task_union            # init current pointer

        daddiu  sp, $28, KERNEL_STACK_SIZE-32

        set_saved_sp    sp, t0, t1

        dsubu   sp, 4*SZREG                     # init stack pointer

        j       init_arch

        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)

#ifdef CONFIG_SGI_IP27

        GET_NASID_ASM   t1

        dli     t0, KLDIR_OFFSET + (KLI_KERN_VARS * KLDIR_ENT_SIZE) + \

                    KLDIR_OFF_POINTER + K0BASE

        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 */

        CLI

        /*

         * For the moment set ST0_KU so the CPU will not spit fire when

         * executing 64-bit instructions.  The full initialization of the

         * CPU's status register is done later in per_cpu_trap_init().

         */

        mfc0    t0, CP0_STATUS

        or      t0, ST0_KX

        mtc0    t0, CP0_STATUS

        jal     start_secondary                 # XXX: IP27: cboot

        END(smp_bootstrap)

#endif /* CONFIG_SMP */

        __FINIT

        declare_saved_sp

        .macro  page name, order=0

        .globl  \name

\name:  .size   \name, (_PAGE_SIZE << \order)

        .org    . + (_PAGE_SIZE << \order)

        .type   \name, @object

        .endm

        .data

        .align  12

        page    swapper_pg_dir, _PGD_ORDER

        page    invalid_pmd_table, _PMD_ORDER

        page    invalid_pte_table, _PTE_ORDER

        page    kptbl, _PGD_ORDER

        .globl  ekptbl

        page    kpmdtbl, 0

ekptbl: