Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*
 * 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 - 99, 2003, 06 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/init.h>
#include <linux/threads.h>

#include <asm/addrspace.h>
#include <asm/asm.h>
#include <asm/asmmacro.h>
#include <asm/irqflags.h>
#include <asm/regdef.h>
#include <asm/page.h>
#include <asm/mipsregs.h>
#include <asm/stackframe.h>

#include <kernel-entry-init.h>

        /*
         * 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
#ifdef CONFIG_MIPS_MT_SMTC
        /*
         * For SMTC, we need to set privilege and disable interrupts only for
         * the current TC, using the TCStatus register.
         */
        mfc0    t0, CP0_TCSTATUS
        /* Fortunately CU 0 is in the same place in both registers */
        /* Set TCU0, TMX, TKSU (for later inversion) and IXMT */
        li      t1, ST0_CU0 | 0x08001c00
        or      t0, t1
        /* Clear TKSU, leave IXMT */
        xori    t0, 0x00001800
        mtc0    t0, CP0_TCSTATUS
        _ehb
        /* We need to leave the global IE bit set, but clear EXL...*/
        mfc0    t0, CP0_STATUS
        or      t0, ST0_CU0 | ST0_EXL | ST0_ERL | \set | \clr
        xor     t0, ST0_EXL | ST0_ERL | \clr
        mtc0    t0, CP0_STATUS
#else
        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
#endif
        .set    pop
        .endm

        .macro  setup_c0_status_pri
#ifdef CONFIG_64BIT
        setup_c0_status ST0_KX 0
#else
        setup_c0_status 0 0
#endif
        .endm

        .macro  setup_c0_status_sec
#ifdef CONFIG_64BIT
        setup_c0_status ST0_KX ST0_BEV
#else
        setup_c0_status 0 ST0_BEV
#endif
        .endm

#ifndef CONFIG_NO_EXCEPT_FILL
        /*
         * Reserved space for exception handlers.
         * Necessary for machines which link their kernels at KSEG0.
         */
        .fill   0x400
#endif

EXPORT(_stext)

#ifdef CONFIG_BOOT_RAW
        /*
         * Give us a fighting chance of running if execution beings at the
         * kernel load address.  This is needed because this platform does
         * not have a ELF loader yet.
         */
FEXPORT(__kernel_entry)
        j       kernel_entry
#endif

        __INIT_REFOK

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

        kernel_entry_setup                      # cpu specific setup

        setup_c0_status_pri

        /* We might not get launched at the address the kernel is linked to,
           so we jump there.  */
        PTR_LA  t0, 0f
        jr      t0
0:

#ifdef CONFIG_MIPS_MT_SMTC
        /*
         * In SMTC kernel, "CLI" is thread-specific, in TCStatus.
         * We still need to enable interrupts globally in Status,
         * and clear EXL/ERL.
         *
         * TCContext is used to track interrupt levels under
         * service in SMTC kernel. Clear for boot TC before
         * allowing any interrupts.
         */
        mtc0    zero, CP0_TCCONTEXT

        mfc0    t0, CP0_STATUS
        ori     t0, t0, 0xff1f
        xori    t0, t0, 0x001e
        mtc0    t0, CP0_STATUS
#endif /* CONFIG_MIPS_MT_SMTC */

        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

        MTC0            zero, CP0_CONTEXT       # clear context register
        PTR_LA          $28, init_thread_union
        PTR_LI          sp, _THREAD_SIZE - 32
        PTR_ADDU        sp, $28
        set_saved_sp    sp, t0, t1
        PTR_SUBU        sp, 4 * SZREG           # init stack pointer

        j               start_kernel
        END(kernel_entry)

        __INIT

#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_MIPS_MT_SMTC
        /*
         * Read-modify-writes of Status must be atomic, and this
         * is one case where CLI is invoked without EXL being
         * necessarily set. The CLI and setup_c0_status will
         * in fact be redundant for all but the first TC of
         * each VPE being booted.
         */
        DMT     10      # dmt t2 /* t0, t1 are used by CLI and setup_c0_status() */
        jal     mips_ihb
#endif /* CONFIG_MIPS_MT_SMTC */
        setup_c0_status_sec
        smp_slave_setup
#ifdef CONFIG_MIPS_MT_SMTC
        andi    t2, t2, VPECONTROL_TE
        beqz    t2, 2f
        EMT             # emt
2:
#endif /* CONFIG_MIPS_MT_SMTC */
        j       start_secondary
        END(smp_bootstrap)
#endif /* CONFIG_SMP */

        __FINIT