/* $NetBSD: cpu.c,v 1.4 2023/12/05 19:16:48 andvar Exp $ */

/*
 * Copyright 2000, 2001
 * Broadcom Corporation. All rights reserved.
 *
 * This software is furnished under license and may be used and copied only
 * in accordance with the following terms and conditions.  Subject to these
 * conditions, you may download, copy, install, use, modify and distribute
 * modified or unmodified copies of this software in source and/or binary
 * form. No title or ownership is transferred hereby.
 *
 * 1) Any source code used, modified or distributed must reproduce and
 *    retain this copyright notice and list of conditions as they appear in
 *    the source file.
 *
 * 2) No right is granted to use any trade name, trademark, or logo of
 *    Broadcom Corporation.  The "Broadcom Corporation" name may not be
 *    used to endorse or promote products derived from this software
 *    without the prior written permission of Broadcom Corporation.
 *
 * 3) THIS SOFTWARE IS PROVIDED "AS-IS" AND ANY EXPRESS OR IMPLIED
 *    WARRANTIES, INCLUDING BUT NOT LIMITED TO, ANY IMPLIED WARRANTIES OF
 *    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR
 *    NON-INFRINGEMENT ARE DISCLAIMED. IN NO EVENT SHALL BROADCOM BE LIABLE
 *    FOR ANY DAMAGES WHATSOEVER, AND IN PARTICULAR, BROADCOM SHALL NOT BE
 *    LIABLE FOR 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), EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: cpu.c,v 1.4 2023/12/05 19:16:48 andvar Exp $");

#include "opt_multiprocessor.h"

#include <sys/param.h>
#include <sys/cpu.h>
#include <sys/device.h>
#include <sys/kernel.h>
#include <sys/systm.h>

#include <mips/locore.h>
#include <mips/cache.h>

#include <evbmips/sbmips/cpuvar.h>
#include <evbmips/sbmips/systemsw.h>

#include <mips/sibyte/include/zbbusvar.h>
#include <mips/sibyte/include/sb1250_regs.h>
#include <mips/sibyte/include/sb1250_scd.h>
#include <mips/sibyte/dev/sbscdvar.h>
#include <mips/cfe/cfe_api.h>

#define READ_REG(rp)            mips3_ld((register_t)(rp))

static int      cpu_match(device_t, cfdata_t, void *);
static void     cpu_attach(device_t, device_t, void *);

CFATTACH_DECL_NEW(cpu, sizeof(struct cpu_softc),
    cpu_match, cpu_attach, NULL, NULL);

static u_int found = 0;

static int
cpu_match(device_t parent, cfdata_t match, void *aux)
{
        struct zbbus_attach_args *zap = aux;
        int part;

        if (zap->za_locs.za_type != ZBBUS_ENTTYPE_CPU)
                return (0);

        /*
         * The 3rd hex digit of the part number is the number of CPUs;
         * ref Table 26, p38 1250-UM101-R.
         */
        part = G_SYS_PART(READ_REG(MIPS_PHYS_TO_KSEG1(A_SCD_SYSTEM_REVISION)));
        return (found < ((part >> 8) & 0xf));
}

static void
cpu_attach(device_t parent, device_t self, void *aux)
{
        struct cpu_info *ci;
        struct cpu_softc * const cpu = device_private(self);
        const char * const xname = device_xname(self);
        uint32_t config;
        int plldiv;

        found++;

        /* XXX this code must run on the target CPU */
        config = mips3_cp0_config_read();
        __USE(config);
        KASSERT((config & MIPS3_CONFIG_K0_MASK) == 5);

        /* Determine CPU frequency */

        /* XXX:  We should determine the CPU frequency from a time source
         *       not coupled with the CPU crystal, like the RTC.  Unfortunately
         *       we don't attach that yet...
         */
        plldiv = G_SYS_PLL_DIV(READ_REG(MIPS_PHYS_TO_KSEG1(A_SCD_SYSTEM_CFG)));
        if (plldiv == 0) {
                aprint_normal(": PLL_DIV of zero found, assuming 6 (300MHz)\n");
                plldiv = 6;

                aprint_normal("%s", xname);
        }

        if (found == 1) {
                ci = curcpu();
                ci->ci_cpu_freq = 50000000 * plldiv;
                /* Compute the delay divisor. */
                ci->ci_divisor_delay = (ci->ci_cpu_freq + 500000) / 1000000;
                /* Compute clock cycles per hz */
                ci->ci_cycles_per_hz = (ci->ci_cpu_freq + hz / 2 ) / hz;

                aprint_normal(": %lu.%02luMHz (hz cycles = %lu, delay divisor = %lu)\n",
                    ci->ci_cpu_freq / 1000000,
                    (ci->ci_cpu_freq % 1000000) / 10000,
                    ci->ci_cycles_per_hz, ci->ci_divisor_delay);

                KASSERT(ci->ci_cpuid == 0);

                cpu->sb1cpu_dev = self;
                cpu->sb1cpu_ci = ci;
                ci->ci_softc = cpu;

                sb1250_cpu_init(cpu);
        } else {
#if defined(MULTIPROCESSOR)
                int status;
                ci = cpu_info_alloc(NULL, found - 1, 0, found - 1, 0);
                KASSERT(ci);

                cpu->sb1cpu_dev = self;
                cpu->sb1cpu_ci = ci;
                ci->ci_softc = cpu;

                sb1250_cpu_init(cpu);

                status = cfe_cpu_start(ci->ci_cpuid, cpu_trampoline,
                    (long) ci->ci_data.cpu_idlelwp->l_md.md_utf, 0,
                    (long) ci);
                if (status != 0) {
                        aprint_error(": CFE call to start failed: %d\n",
                            status);
                }
                for (size_t i = 0; i < 10000; i++) {
                        if (kcpuset_isset(cpus_hatched, cpu_index(ci)))
                                 break;
                        DELAY(100);
                }
                if (!kcpuset_isset(cpus_hatched, cpu_index(ci))) {
                        aprint_error(": failed to hatch!\n");
                        return;
                }
#else
                aprint_normal("\n");
                aprint_normal_dev(self,
                    "processor off-line; "
                    "multiprocessor support not present in kernel\n");
                return;
#endif
        }

        /*
         * Announce ourselves.
         */
        aprint_normal("%s: ", xname);
        cpu_identify(self);

        cpu_attach_common(self, ci);
}