FreeBSD/Linux Kernel Cross Reference
sys/arm/freescale/imx/imx6_mp.c

     /*-
      * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
      *
      * Copyright (c) 2014 Juergen Weiss <weiss@uni-mainz.de>
      * Copyright (c) 2014 Ian Lepore <ian@freebsd.org>
      * All rights reserved.
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
     * are met:
     * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/bus.h>
    #include <sys/kernel.h>
    #include <sys/lock.h>
    #include <sys/mutex.h>
    #include <sys/smp.h>
    
    #include <vm/vm.h>
    #include <vm/pmap.h>
    
    #include <machine/cpu.h>
    #include <machine/smp.h>
    #include <machine/fdt.h>
    #include <machine/intr.h>
    #include <machine/platform.h>
    #include <machine/platformvar.h>
    
    #include <arm/freescale/imx/imx6_machdep.h>
    
    #define SCU_PHYSBASE                    0x00a00000
    #define SCU_SIZE                        0x00001000
    
    #define SCU_CONTROL_REG                 0x00
    #define   SCU_CONTROL_ENABLE              (1 << 0)
    #define SCU_CONFIG_REG                  0x04
    #define   SCU_CONFIG_REG_NCPU_MASK        0x03
    #define SCU_CPUPOWER_REG                0x08
    #define SCU_INV_TAGS_REG                0x0c
    #define SCU_DIAG_CONTROL                0x30
    #define   SCU_DIAG_DISABLE_MIGBIT         (1 << 0)
    #define SCU_FILTER_START_REG            0x40
    #define SCU_FILTER_END_REG              0x44
    #define SCU_SECURE_ACCESS_REG           0x50
    #define SCU_NONSECURE_ACCESS_REG        0x54
    
    #define SRC_PHYSBASE                    0x020d8000
    #define SRC_SIZE                        0x4000
    #define SRC_CONTROL_REG                 0x00
    #define SRC_CONTROL_C1ENA_SHIFT           22    /* Bit for Core 1 enable */
    #define SRC_CONTROL_C1RST_SHIFT           14    /* Bit for Core 1 reset */
    #define SRC_GPR0_C1FUNC                 0x20    /* Register for Core 1 entry func */
    #define SRC_GPR1_C1ARG                  0x24    /* Register for Core 1 entry arg */
    
    void
    imx6_mp_setmaxid(platform_t plat)
    {
            bus_space_handle_t scu;
            int hwcpu, ncpu;
            uint32_t val;
    
            /* If we've already set the global vars don't bother to do it again. */
            if (mp_ncpus != 0)
                    return;
    
            if (bus_space_map(fdtbus_bs_tag, SCU_PHYSBASE, SCU_SIZE, 0, &scu) != 0)
                    panic("Couldn't map the SCU\n");
            val = bus_space_read_4(fdtbus_bs_tag, scu, SCU_CONFIG_REG);
            hwcpu = (val & SCU_CONFIG_REG_NCPU_MASK) + 1;
            bus_space_unmap(fdtbus_bs_tag, scu, SCU_SIZE);
    
            ncpu = hwcpu;
            TUNABLE_INT_FETCH("hw.ncpu", &ncpu);
            if (ncpu < 1 || ncpu > hwcpu)
                    ncpu = hwcpu;
    
            mp_ncpus = ncpu;
            mp_maxid = ncpu - 1;
    }
   
   void
   imx6_mp_start_ap(platform_t plat)
   {
           bus_space_handle_t scu;
           bus_space_handle_t src;
   
           uint32_t val;
           int i;
   
           if (bus_space_map(fdtbus_bs_tag, SCU_PHYSBASE, SCU_SIZE, 0, &scu) != 0)
                   panic("Couldn't map the SCU\n");
           if (bus_space_map(fdtbus_bs_tag, SRC_PHYSBASE, SRC_SIZE, 0, &src) != 0)
                   panic("Couldn't map the system reset controller (SRC)\n");
   
           /*
            * Invalidate SCU cache tags.  The 0x0000ffff constant invalidates all
            * ways on all cores 0-3.  Per the ARM docs, it's harmless to write to
            * the bits for cores that are not present.
            */
           bus_space_write_4(fdtbus_bs_tag, scu, SCU_INV_TAGS_REG, 0x0000ffff);
   
           /*
            * Erratum ARM/MP: 764369 (problems with cache maintenance).
            * Setting the "disable-migratory bit" in the undocumented SCU
            * Diagnostic Control Register helps work around the problem.
            */
           val = bus_space_read_4(fdtbus_bs_tag, scu, SCU_DIAG_CONTROL);
           bus_space_write_4(fdtbus_bs_tag, scu, SCU_DIAG_CONTROL, 
               val | SCU_DIAG_DISABLE_MIGBIT);
   
           /*
            * Enable the SCU, then clean the cache on this core.  After these two
            * operations the cache tag ram in the SCU is coherent with the contents
            * of the cache on this core.  The other cores aren't running yet so
            * their caches can't contain valid data yet, but we've initialized
            * their SCU tag ram above, so they will be coherent from startup.
            */
           val = bus_space_read_4(fdtbus_bs_tag, scu, SCU_CONTROL_REG);
           bus_space_write_4(fdtbus_bs_tag, scu, SCU_CONTROL_REG, 
               val | SCU_CONTROL_ENABLE);
           dcache_wbinv_poc_all();
   
           /*
            * For each AP core, set the entry point address and argument registers,
            * and set the core-enable and core-reset bits in the control register.
            */
           val = bus_space_read_4(fdtbus_bs_tag, src, SRC_CONTROL_REG);
           for (i=1; i < mp_ncpus; i++) {
                   bus_space_write_4(fdtbus_bs_tag, src, SRC_GPR0_C1FUNC + 8*i,
                       pmap_kextract((vm_offset_t)mpentry));
                   bus_space_write_4(fdtbus_bs_tag, src, SRC_GPR1_C1ARG  + 8*i, 0);
   
                   val |= ((1 << (SRC_CONTROL_C1ENA_SHIFT - 1 + i )) |
                       ( 1 << (SRC_CONTROL_C1RST_SHIFT - 1 + i)));
           }
           bus_space_write_4(fdtbus_bs_tag, src, SRC_CONTROL_REG, val);
   
           dsb();
           sev();
   
           bus_space_unmap(fdtbus_bs_tag, scu, SCU_SIZE);
           bus_space_unmap(fdtbus_bs_tag, src, SRC_SIZE);
   }

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