/* $NetBSD: cpu_acpi.c,v 1.18 2025/01/30 00:43:56 jmcneill Exp $ */

/*-
 * Copyright (c) 2018 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Jared McNeill <jmcneill@invisible.ca>.
 *
 * 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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``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 FOUNDATION OR CONTRIBUTORS
 * 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 "tprof.h"
#include "opt_multiprocessor.h"

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: cpu_acpi.c,v 1.18 2025/01/30 00:43:56 jmcneill Exp $");

#include <sys/param.h>
#include <sys/bus.h>
#include <sys/cpu.h>
#include <sys/device.h>
#include <sys/interrupt.h>
#include <sys/kcpuset.h>
#include <sys/kmem.h>
#include <sys/reboot.h>

#include <dev/acpi/acpireg.h>
#include <dev/acpi/acpivar.h>
#include <dev/acpi/acpi_srat.h>
#include <external/bsd/acpica/dist/include/amlresrc.h>

#include <arm/armreg.h>
#include <arm/cpu.h>
#include <arm/cpufunc.h>
#include <arm/cpuvar.h>
#include <arm/locore.h>

#include <arm/arm/psci.h>

#define LPI_IDLE_FACTOR         3

#if NTPROF > 0
#include <dev/tprof/tprof_armv8.h>
#endif

static int      cpu_acpi_match(device_t, cfdata_t, void *);
static void     cpu_acpi_attach(device_t, device_t, void *);

static void     cpu_acpi_probe_lpi(device_t, struct cpu_info *ci);
void            cpu_acpi_lpi_idle(void);

#if NTPROF > 0
static void     cpu_acpi_tprof_init(device_t);
#endif

CFATTACH_DECL2_NEW(cpu_acpi, 0,
    cpu_acpi_match, cpu_acpi_attach, NULL, NULL,
    cpu_rescan, cpu_childdetached);

#ifdef MULTIPROCESSOR
static register_t
cpu_acpi_mpstart_pa(void)
{

        return (register_t)KERN_VTOPHYS((vaddr_t)cpu_mpstart);
}
#endif /* MULTIPROCESSOR */

static int
cpu_acpi_match(device_t parent, cfdata_t cf, void *aux)
{
        ACPI_SUBTABLE_HEADER *hdrp = aux;
        ACPI_MADT_GENERIC_INTERRUPT *gicc;

        if (hdrp->Type != ACPI_MADT_TYPE_GENERIC_INTERRUPT)
                return 0;

        gicc = (ACPI_MADT_GENERIC_INTERRUPT *)hdrp;

        return (gicc->Flags & ACPI_MADT_ENABLED) != 0;
}

static void
cpu_acpi_attach(device_t parent, device_t self, void *aux)
{
        prop_dictionary_t dict = device_properties(self);
        ACPI_MADT_GENERIC_INTERRUPT *gicc = aux;
        const uint64_t mpidr = gicc->ArmMpidr;
        const int unit = device_unit(self);
        struct cpu_info *ci = &cpu_info_store[unit];
        struct acpisrat_node *node;

#ifdef MULTIPROCESSOR
        if (cpu_mpidr_aff_read() != mpidr && (boothowto & RB_MD1) == 0) {
                const u_int cpuindex = device_unit(self);
                int error;

                cpu_mpidr[cpuindex] = mpidr;
                cpu_dcache_wb_range((vaddr_t)&cpu_mpidr[cpuindex],
                    sizeof(cpu_mpidr[cpuindex]));

                /* XXX support spin table */
                error = psci_cpu_on(mpidr, cpu_acpi_mpstart_pa(), 0);
                if (error != PSCI_SUCCESS) {
                        aprint_error_dev(self, "failed to start CPU\n");
                        return;
                }

                sev();

                for (u_int i = 0x10000000; i > 0; i--) {
                        if (cpu_hatched_p(cpuindex))
                                 break;
                }
        }
#endif /* MULTIPROCESSOR */

        /* Assume that less efficient processors are faster. */
        prop_dictionary_set_uint32(dict, "capacity_dmips_mhz",
            gicc->EfficiencyClass);

        /* Store the ACPI Processor UID in cpu_info */
        ci->ci_acpiid = gicc->Uid;

        /* Scan SRAT for NUMA info. */
        if (cpu_mpidr_aff_read() == mpidr) {
                acpisrat_init();
        }
        node = acpisrat_get_node(gicc->Uid);
        if (node != NULL) {
                ci->ci_numa_id = node->nodeid;
        }

        /* Attach the CPU */
        cpu_attach(self, mpidr);

        if (ci->ci_dev == NULL) {
                /* Not configured */
                return;
        }

        /* Probe for low-power idle states. */
        cpu_acpi_probe_lpi(self, ci);

#if NTPROF > 0
        if (cpu_mpidr_aff_read() == mpidr && armv8_pmu_detect())
                config_interrupts(self, cpu_acpi_tprof_init);
#endif
}

static void
cpu_acpi_probe_lpi(device_t dev, struct cpu_info *ci)
{
        ACPI_HANDLE hdl;
        ACPI_BUFFER buf;
        ACPI_OBJECT *obj, *lpi;
        ACPI_STATUS rv;
        uint32_t levelid;
        uint32_t numlpi;
        uint32_t n;
        int enable_lpi;

        if (get_bootconf_option(boot_args, "nolpi",
                                BOOTOPT_TYPE_BOOLEAN, &enable_lpi) &&
            !enable_lpi) {
                return;
        }

        hdl = acpi_match_cpu_info(ci);
        if (hdl == NULL) {
                return;
        }
        rv = AcpiGetHandle(hdl, "_LPI", &hdl);
        if (ACPI_FAILURE(rv)) {
                return;
        }
        rv = acpi_eval_struct(hdl, NULL, &buf);
        if (ACPI_FAILURE(rv)) {
                return;
        }

        obj = buf.Pointer;
        if (obj->Type != ACPI_TYPE_PACKAGE ||
            obj->Package.Count < 3 ||
            obj->Package.Elements[1].Type != ACPI_TYPE_INTEGER ||
            obj->Package.Elements[2].Type != ACPI_TYPE_INTEGER) {
                goto out;
        }
        levelid = obj->Package.Elements[1].Integer.Value;
        if (levelid != 0) {
                /* We depend on platform coordination for now. */
                goto out;
        }
        numlpi = obj->Package.Elements[2].Integer.Value;
        if (obj->Package.Count < 3 + numlpi || numlpi == 0) {
                goto out;
        }
        ci->ci_lpi = kmem_zalloc(sizeof(*ci->ci_lpi) * numlpi, KM_SLEEP);
        for (n = 0; n < numlpi; n++) {
                lpi = &obj->Package.Elements[3 + n];
                if (lpi->Type != ACPI_TYPE_PACKAGE ||
                    lpi->Package.Count < 10 ||
                    lpi->Package.Elements[0].Type != ACPI_TYPE_INTEGER ||
                    lpi->Package.Elements[1].Type != ACPI_TYPE_INTEGER ||
                    lpi->Package.Elements[2].Type != ACPI_TYPE_INTEGER ||
                    lpi->Package.Elements[3].Type != ACPI_TYPE_INTEGER ||
                    !(lpi->Package.Elements[6].Type == ACPI_TYPE_BUFFER ||
                      lpi->Package.Elements[6].Type == ACPI_TYPE_INTEGER)) {
                        continue;
                }

                if ((lpi->Package.Elements[2].Integer.Value & 1) == 0) {
                        /* LPI state is not enabled */
                        continue;
                }

                ci->ci_lpi[ci->ci_nlpi].min_res
                    = lpi->Package.Elements[0].Integer.Value;
                ci->ci_lpi[ci->ci_nlpi].wakeup_latency =
                    lpi->Package.Elements[1].Integer.Value;
                ci->ci_lpi[ci->ci_nlpi].save_restore_flags =
                    lpi->Package.Elements[3].Integer.Value;
                if (ci->ci_lpi[ci->ci_nlpi].save_restore_flags != 0) {
                        /* Not implemented yet */
                        continue;
                }
                if (lpi->Package.Elements[6].Type == ACPI_TYPE_INTEGER) {
                        ci->ci_lpi[ci->ci_nlpi].reg_addr =
                            lpi->Package.Elements[6].Integer.Value;
                } else {
                        ACPI_GENERIC_ADDRESS addr;

                        KASSERT(lpi->Package.Elements[6].Type ==
                                ACPI_TYPE_BUFFER);

                        if (lpi->Package.Elements[6].Buffer.Length <
                            sizeof(AML_RESOURCE_GENERIC_REGISTER)) {
                                continue;
                        }
                        memcpy(&addr, lpi->Package.Elements[6].Buffer.Pointer +
                            sizeof(AML_RESOURCE_LARGE_HEADER), sizeof(addr));
                        ci->ci_lpi[ci->ci_nlpi].reg_addr = addr.Address;
                }

                if (lpi->Package.Elements[9].Type == ACPI_TYPE_STRING) {
                        ci->ci_lpi[ci->ci_nlpi].name =
                            kmem_asprintf("LPI state %s",
                                lpi->Package.Elements[9].String.Pointer);
                } else {
                        ci->ci_lpi[ci->ci_nlpi].name =
                            kmem_asprintf("LPI state %u", n + 1);
                }

                aprint_verbose_dev(ci->ci_dev,
                    "%s: min res %u, wakeup latency %u, flags %#x, "
                    "register %#x\n",
                    ci->ci_lpi[ci->ci_nlpi].name,
                    ci->ci_lpi[ci->ci_nlpi].min_res,
                    ci->ci_lpi[ci->ci_nlpi].wakeup_latency,
                    ci->ci_lpi[ci->ci_nlpi].save_restore_flags,
                    ci->ci_lpi[ci->ci_nlpi].reg_addr);

                evcnt_attach_dynamic(&ci->ci_lpi[ci->ci_nlpi].events,
                    EVCNT_TYPE_MISC, NULL, ci->ci_cpuname,
                    ci->ci_lpi[ci->ci_nlpi].name);

                ci->ci_nlpi++;
        }

        if (ci->ci_nlpi > 0) {
                extern void (*arm_cpu_idle)(void);
                arm_cpu_idle = cpu_acpi_lpi_idle;
        }

out:
        ACPI_FREE(buf.Pointer);
}

static inline void
cpu_acpi_idle(uint32_t addr)
{
        if (addr == LPI_REG_ADDR_WFI) {
                asm volatile("dsb sy; wfi");
        } else {
                psci_cpu_suspend(addr);
        }
}

void
cpu_acpi_lpi_idle(void)
{
        struct cpu_info *ci = curcpu();
        struct timeval start, end;
        int n;

        DISABLE_INTERRUPT();

        microuptime(&start);
        for (n = ci->ci_nlpi - 1; n >= 0; n--) {
                if (ci->ci_last_idle >
                    LPI_IDLE_FACTOR * ci->ci_lpi[n].min_res) {
                        cpu_acpi_idle(ci->ci_lpi[n].reg_addr);
                        ci->ci_lpi[n].events.ev_count++;
                        break;
                }
        }
        if (n == -1) {
                /* Nothing in _LPI, let's just WFI. */
                cpu_acpi_idle(LPI_REG_ADDR_WFI);
        }
        microuptime(&end);
        timersub(&end, &start, &end);

        ci->ci_last_idle = end.tv_sec * 1000000 + end.tv_usec;

        ENABLE_INTERRUPT();
}

#if NTPROF > 0
static struct cpu_info *
cpu_acpi_find_processor(UINT32 uid)
{
        CPU_INFO_ITERATOR cii;
        struct cpu_info *ci;

        for (CPU_INFO_FOREACH(cii, ci)) {
                if (ci->ci_acpiid == uid)
                        return ci;
        }

        return NULL;
}

static ACPI_STATUS
cpu_acpi_tprof_intr_establish(ACPI_SUBTABLE_HEADER *hdrp, void *aux)
{
        device_t dev = aux;
        ACPI_MADT_GENERIC_INTERRUPT *gicc;
        struct cpu_info *ci;
        char xname[16];
        kcpuset_t *set;
        int error;
        void *ih;

        if (hdrp->Type != ACPI_MADT_TYPE_GENERIC_INTERRUPT)
                return AE_OK;

        gicc = (ACPI_MADT_GENERIC_INTERRUPT *)hdrp;
        if ((gicc->Flags & ACPI_MADT_ENABLED) == 0)
                return AE_OK;

        const bool cpu_primary_p = cpu_info_store[0].ci_cpuid == gicc->ArmMpidr;
        const bool intr_ppi_p = gicc->PerformanceInterrupt < 32;
        const int type = (gicc->Flags & ACPI_MADT_PERFORMANCE_IRQ_MODE) ?
            IST_EDGE : IST_LEVEL;

        if (intr_ppi_p && !cpu_primary_p)
                return AE_OK;

        ci = cpu_acpi_find_processor(gicc->Uid);
        if (ci == NULL) {
                aprint_error_dev(dev, "couldn't find processor %#x\n",
                    gicc->Uid);
                return AE_OK;
        }

        if (intr_ppi_p) {
                strlcpy(xname, "pmu", sizeof(xname));
        } else {
                snprintf(xname, sizeof(xname), "pmu %s", cpu_name(ci));
        }

        ih = intr_establish_xname(gicc->PerformanceInterrupt, IPL_HIGH,
            type | IST_MPSAFE, armv8_pmu_intr, NULL, xname);
        if (ih == NULL) {
                aprint_error_dev(dev, "couldn't establish %s interrupt\n",
                    xname);
                return AE_OK;
        }

        if (!intr_ppi_p) {
                kcpuset_create(&set, true);
                kcpuset_set(set, cpu_index(ci));
                error = interrupt_distribute(ih, set, NULL);
                kcpuset_destroy(set);

                if (error) {
                        aprint_error_dev(dev,
                            "failed to distribute %s interrupt: %d\n",
                            xname, error);
                        return AE_OK;
                }
        }

        aprint_normal("%s: PMU interrupting on irq %d\n", cpu_name(ci),
            gicc->PerformanceInterrupt);

        return AE_OK;
}

static void
cpu_acpi_tprof_init(device_t self)
{
        int err = armv8_pmu_init();
        if (err) {
                aprint_error_dev(self,
                    "failed to initialize PMU event counter\n");
                return;
        }

        if (acpi_madt_map() != AE_OK) {
                aprint_error_dev(self,
                    "failed to map MADT, performance counters not available\n");
                return;
        }
        acpi_madt_walk(cpu_acpi_tprof_intr_establish, self);
        acpi_madt_unmap();
}
#endif