/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2010 Hudson River Trading LLC
 * Written by: John H. Baldwin <jhb@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 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 AUTHOR 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 <sys/cdefs.h>
#include "opt_vm.h"

#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 <sys/vmmeter.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_param.h>
#include <vm/vm_page.h>
#include <vm/vm_phys.h>

#include <contrib/dev/acpica/include/acpi.h>
#include <contrib/dev/acpica/include/aclocal.h>
#include <contrib/dev/acpica/include/actables.h>

#include <machine/md_var.h>

#include <dev/acpica/acpivar.h>

#if MAXMEMDOM > 1
static struct cpu_info {
        bool enabled:1;
        bool has_memory:1;
        int domain;
        int id;
} *cpus;

static int max_cpus;
static int last_cpu;

struct mem_affinity mem_info[VM_PHYSSEG_MAX + 1];
int num_mem;

static ACPI_TABLE_SRAT *srat;
static vm_paddr_t srat_physaddr;

static int domain_pxm[MAXMEMDOM];
static int ndomain;
static vm_paddr_t maxphyaddr;

static ACPI_TABLE_SLIT *slit;
static vm_paddr_t slit_physaddr;
static int vm_locality_table[MAXMEMDOM * MAXMEMDOM];

static void     srat_walk_table(acpi_subtable_handler *handler, void *arg);

/*
 * SLIT parsing.
 */

static void
slit_parse_table(ACPI_TABLE_SLIT *s)
{
        int i, j;
        int i_domain, j_domain;
        int offset = 0;
        uint8_t e;

        /*
         * This maps the SLIT data into the VM-domain centric view.
         * There may be sparse entries in the PXM namespace, so
         * remap them to a VM-domain ID and if it doesn't exist,
         * skip it.
         *
         * It should result in a packed 2d array of VM-domain
         * locality information entries.
         */

        if (bootverbose)
                printf("SLIT.Localities: %d\n", (int) s->LocalityCount);
        for (i = 0; i < s->LocalityCount; i++) {
                i_domain = acpi_map_pxm_to_vm_domainid(i);
                if (i_domain < 0)
                        continue;

                if (bootverbose)
                        printf("%d: ", i);
                for (j = 0; j < s->LocalityCount; j++) {
                        j_domain = acpi_map_pxm_to_vm_domainid(j);
                        if (j_domain < 0)
                                continue;
                        e = s->Entry[i * s->LocalityCount + j];
                        if (bootverbose)
                                printf("%d ", (int) e);
                        /* 255 == "no locality information" */
                        if (e == 255)
                                vm_locality_table[offset] = -1;
                        else
                                vm_locality_table[offset] = e;
                        offset++;
                }
                if (bootverbose)
                        printf("\n");
        }
}

/*
 * Look for an ACPI System Locality Distance Information Table ("SLIT")
 */
static int
parse_slit(void)
{

        if (resource_disabled("slit", 0)) {
                return (-1);
        }

        slit_physaddr = acpi_find_table(ACPI_SIG_SLIT);
        if (slit_physaddr == 0) {
                return (-1);
        }

        /*
         * Make a pass over the table to populate the cpus[] and
         * mem_info[] tables.
         */
        slit = acpi_map_table(slit_physaddr, ACPI_SIG_SLIT);
        slit_parse_table(slit);
        acpi_unmap_table(slit);
        slit = NULL;

        return (0);
}

/*
 * SRAT parsing.
 */

/*
 * Returns true if a memory range overlaps with at least one range in
 * phys_avail[].
 */
static int
overlaps_phys_avail(vm_paddr_t start, vm_paddr_t end)
{
        int i;

        for (i = 0; phys_avail[i] != 0 && phys_avail[i + 1] != 0; i += 2) {
                if (phys_avail[i + 1] <= start)
                        continue;
                if (phys_avail[i] < end)
                        return (1);
                break;
        }
        return (0);
}

/*
 * On x86 we can use the cpuid to index the cpus array, but on arm64
 * we have an ACPI Processor UID with a larger range.
 *
 * Use this variable to indicate if the cpus can be stored by index.
 */
#ifdef __aarch64__
static const int cpus_use_indexing = 0;
#else
static const int cpus_use_indexing = 1;
#endif

/*
 * Find CPU by processor ID (APIC ID on x86, Processor UID on arm64)
 */
static struct cpu_info *
cpu_find(int cpuid)
{
        int i;

        if (cpus_use_indexing) {
                if (cpuid <= last_cpu && cpus[cpuid].enabled)
                        return (&cpus[cpuid]);
        } else {
                for (i = 0; i <= last_cpu; i++)
                        if (cpus[i].id == cpuid)
                                return (&cpus[i]);
        }
        return (NULL);
}

/*
 * Find CPU by pcpu pointer.
 */
static struct cpu_info *
cpu_get_info(struct pcpu *pc)
{
        struct cpu_info *cpup;
        int id;

#ifdef __aarch64__
        id = pc->pc_acpi_id;
#else
        id = pc->pc_apic_id;
#endif
        cpup = cpu_find(id);
        if (cpup == NULL)
                panic("SRAT: CPU with ID %u is not known", id);
        return (cpup);
}

/*
 * Add proximity information for a new CPU.
 */
static struct cpu_info *
cpu_add(int cpuid, int domain)
{
        struct cpu_info *cpup;

        if (cpus_use_indexing) {
                if (cpuid >= max_cpus)
                        return (NULL);
                last_cpu = imax(last_cpu, cpuid);
                cpup = &cpus[cpuid];
        } else {
                if (last_cpu >= max_cpus - 1)
                        return (NULL);
                cpup = &cpus[++last_cpu];
        }
        cpup->domain = domain;
        cpup->id = cpuid;
        cpup->enabled = 1;
        return (cpup);
}

static void
srat_parse_entry(ACPI_SUBTABLE_HEADER *entry, void *arg)
{
        ACPI_SRAT_CPU_AFFINITY *cpu;
        ACPI_SRAT_X2APIC_CPU_AFFINITY *x2apic;
        ACPI_SRAT_MEM_AFFINITY *mem;
        ACPI_SRAT_GICC_AFFINITY *gicc;
        static struct cpu_info *cpup;
        uint64_t base, length;
        int domain, i, slot;

        switch (entry->Type) {
        case ACPI_SRAT_TYPE_CPU_AFFINITY:
                cpu = (ACPI_SRAT_CPU_AFFINITY *)entry;
                domain = cpu->ProximityDomainLo |
                    cpu->ProximityDomainHi[0] << 8 |
                    cpu->ProximityDomainHi[1] << 16 |
                    cpu->ProximityDomainHi[2] << 24;
                if (bootverbose)
                        printf("SRAT: Found CPU APIC ID %u domain %d: %s\n",
                            cpu->ApicId, domain,
                            (cpu->Flags & ACPI_SRAT_CPU_ENABLED) ?
                            "enabled" : "disabled");
                if (!(cpu->Flags & ACPI_SRAT_CPU_ENABLED))
                        break;
                cpup = cpu_find(cpu->ApicId);
                if (cpup != NULL) {
                        printf("SRAT: Duplicate local APIC ID %u\n",
                            cpu->ApicId);
                        *(int *)arg = ENXIO;
                        break;
                }
                cpup = cpu_add(cpu->ApicId, domain);
                if (cpup == NULL)
                        printf("SRAT: Ignoring local APIC ID %u (too high)\n",
                            cpu->ApicId);
                break;
        case ACPI_SRAT_TYPE_X2APIC_CPU_AFFINITY:
                x2apic = (ACPI_SRAT_X2APIC_CPU_AFFINITY *)entry;
                if (bootverbose)
                        printf("SRAT: Found CPU APIC ID %u domain %d: %s\n",
                            x2apic->ApicId, x2apic->ProximityDomain,
                            (x2apic->Flags & ACPI_SRAT_CPU_ENABLED) ?
                            "enabled" : "disabled");
                if (!(x2apic->Flags & ACPI_SRAT_CPU_ENABLED))
                        break;
                KASSERT(cpu_find(x2apic->ApicId) == NULL,
                    ("Duplicate local APIC ID %u", x2apic->ApicId));
                cpup = cpu_add(x2apic->ApicId, x2apic->ProximityDomain);
                if (cpup == NULL)
                        printf("SRAT: Ignoring local APIC ID %u (too high)\n",
                            x2apic->ApicId);
                break;
        case ACPI_SRAT_TYPE_GICC_AFFINITY:
                gicc = (ACPI_SRAT_GICC_AFFINITY *)entry;
                if (bootverbose)
                        printf("SRAT: Found CPU UID %u domain %d: %s\n",
                            gicc->AcpiProcessorUid, gicc->ProximityDomain,
                            (gicc->Flags & ACPI_SRAT_GICC_ENABLED) ?
                            "enabled" : "disabled");
                if (!(gicc->Flags & ACPI_SRAT_GICC_ENABLED))
                        break;
                KASSERT(cpu_find(gicc->AcpiProcessorUid) == NULL,
                    ("Duplicate CPU UID %u", gicc->AcpiProcessorUid));
                cpup = cpu_add(gicc->AcpiProcessorUid, gicc->ProximityDomain);
                if (cpup == NULL)
                        printf("SRAT: Ignoring CPU UID %u (too high)\n",
                            gicc->AcpiProcessorUid);
                break;
        case ACPI_SRAT_TYPE_MEMORY_AFFINITY:
                mem = (ACPI_SRAT_MEM_AFFINITY *)entry;
                base = mem->BaseAddress;
                length = mem->Length;
                domain = mem->ProximityDomain;

                if (bootverbose)
                        printf(
                    "SRAT: Found memory domain %d addr 0x%jx len 0x%jx: %s\n",
                            domain, (uintmax_t)base, (uintmax_t)length,
                            (mem->Flags & ACPI_SRAT_MEM_ENABLED) ?
                            "enabled" : "disabled");
                if (!(mem->Flags & ACPI_SRAT_MEM_ENABLED))
                        break;
                if (base >= maxphyaddr ||
                    !overlaps_phys_avail(base, base + length)) {
                        printf("SRAT: Ignoring memory at addr 0x%jx\n",
                            (uintmax_t)base);
                        break;
                }
                if (num_mem == VM_PHYSSEG_MAX) {
                        printf("SRAT: Too many memory regions\n");
                        *(int *)arg = ENXIO;
                        break;
                }
                slot = num_mem;
                for (i = 0; i < num_mem; i++) {
                        if (mem_info[i].domain == domain) {
                                /* Try to extend an existing segment. */
                                if (base == mem_info[i].end) {
                                        mem_info[i].end += length;
                                        return;
                                }
                                if (base + length == mem_info[i].start) {
                                        mem_info[i].start -= length;
                                        return;
                                }
                        }
                        if (mem_info[i].end <= base)
                                continue;
                        if (mem_info[i].start < base + length) {
                                printf("SRAT: Overlapping memory entries\n");
                                *(int *)arg = ENXIO;
                                return;
                        }
                        slot = i;
                }
                for (i = num_mem; i > slot; i--)
                        mem_info[i] = mem_info[i - 1];
                mem_info[slot].start = base;
                mem_info[slot].end = base + length;
                mem_info[slot].domain = domain;
                num_mem++;
                break;
        }
}

/*
 * Ensure each memory domain has at least one CPU and that each CPU
 * has at least one memory domain.
 */
static int
check_domains(void)
{
        int found, i, j;

        for (i = 0; i < num_mem; i++) {
                found = 0;
                for (j = 0; j <= last_cpu; j++)
                        if (cpus[j].enabled &&
                            cpus[j].domain == mem_info[i].domain) {
                                cpus[j].has_memory = 1;
                                found++;
                        }
                if (!found) {
                        printf("SRAT: No CPU found for memory domain %d\n",
                            mem_info[i].domain);
                        return (ENXIO);
                }
        }
        for (i = 0; i <= last_cpu; i++)
                if (cpus[i].enabled && !cpus[i].has_memory) {
                        found = 0;
                        for (j = 0; j < num_mem && !found; j++) {
                                if (mem_info[j].domain == cpus[i].domain)
                                        found = 1;
                        }
                        if (!found) {
                                if (bootverbose)
                                        printf("SRAT: mem dom %d is empty\n",
                                            cpus[i].domain);
                                mem_info[num_mem].start = 0;
                                mem_info[num_mem].end = 0;
                                mem_info[num_mem].domain = cpus[i].domain;
                                num_mem++;
                        }
                }
        return (0);
}

/*
 * Check that the SRAT memory regions cover all of the regions in
 * phys_avail[].
 */
static int
check_phys_avail(void)
{
        vm_paddr_t address;
        int i, j;

        /* j is the current offset into phys_avail[]. */
        address = phys_avail[0];
        j = 0;
        for (i = 0; i < num_mem; i++) {
                /*
                 * Consume as many phys_avail[] entries as fit in this
                 * region.
                 */
                while (address >= mem_info[i].start &&
                    address <= mem_info[i].end) {
                        /*
                         * If we cover the rest of this phys_avail[] entry,
                         * advance to the next entry.
                         */
                        if (phys_avail[j + 1] <= mem_info[i].end) {
                                j += 2;
                                if (phys_avail[j] == 0 &&
                                    phys_avail[j + 1] == 0) {
                                        return (0);
                                }
                                address = phys_avail[j];
                        } else
                                address = mem_info[i].end + 1;
                }
        }
        printf("SRAT: No memory region found for 0x%jx - 0x%jx\n",
            (uintmax_t)phys_avail[j], (uintmax_t)phys_avail[j + 1]);
        return (ENXIO);
}

/*
 * Renumber the memory domains to be compact and zero-based if not
 * already.  Returns an error if there are too many domains.
 */
static int
renumber_domains(void)
{
        int i, j, slot;

        /* Enumerate all the domains. */
        ndomain = 0;
        for (i = 0; i < num_mem; i++) {
                /* See if this domain is already known. */
                for (j = 0; j < ndomain; j++) {
                        if (domain_pxm[j] >= mem_info[i].domain)
                                break;
                }
                if (j < ndomain && domain_pxm[j] == mem_info[i].domain)
                        continue;

                if (ndomain >= MAXMEMDOM) {
                        ndomain = 1;
                        printf("SRAT: Too many memory domains\n");
                        return (EFBIG);
                }

                /* Insert the new domain at slot 'j'. */
                slot = j;
                for (j = ndomain; j > slot; j--)
                        domain_pxm[j] = domain_pxm[j - 1];
                domain_pxm[slot] = mem_info[i].domain;
                ndomain++;
        }

        /* Renumber each domain to its index in the sorted 'domain_pxm' list. */
        for (i = 0; i < ndomain; i++) {
                /*
                 * If the domain is already the right value, no need
                 * to renumber.
                 */
                if (domain_pxm[i] == i)
                        continue;

                /* Walk the cpu[] and mem_info[] arrays to renumber. */
                for (j = 0; j < num_mem; j++)
                        if (mem_info[j].domain == domain_pxm[i])
                                mem_info[j].domain = i;
                for (j = 0; j <= last_cpu; j++)
                        if (cpus[j].enabled && cpus[j].domain == domain_pxm[i])
                                cpus[j].domain = i;
        }

        return (0);
}

/*
 * Look for an ACPI System Resource Affinity Table ("SRAT"),
 * allocate space for cpu information, and initialize globals.
 */
int
acpi_pxm_init(int ncpus, vm_paddr_t maxphys)
{
        unsigned int idx, size;
        vm_paddr_t addr;

        if (resource_disabled("srat", 0))
                return (-1);

        max_cpus = ncpus;
        last_cpu = -1;
        maxphyaddr = maxphys;
        srat_physaddr = acpi_find_table(ACPI_SIG_SRAT);
        if (srat_physaddr == 0)
                return (-1);

        /*
         * Allocate data structure:
         *
         * Find the last physical memory region and steal some memory from
         * it. This is done because at this point in the boot process
         * malloc is still not usable.
         */
        for (idx = 0; phys_avail[idx + 1] != 0; idx += 2);
        KASSERT(idx != 0, ("phys_avail is empty!"));
        idx -= 2;

        size =  sizeof(*cpus) * max_cpus;
        addr = trunc_page(phys_avail[idx + 1] - size);
        KASSERT(addr >= phys_avail[idx],
            ("Not enough memory for SRAT table items"));
        phys_avail[idx + 1] = addr - 1;

        /*
         * We cannot rely on PHYS_TO_DMAP because this code is also used in
         * i386, so use pmap_mapbios to map the memory, this will end up using
         * the default memory attribute (WB), and the DMAP when available.
         */
        cpus = (struct cpu_info *)pmap_mapbios(addr, size);
        bzero(cpus, size);
        return (0);
}

static int
parse_srat(void)
{
        int error;

        /*
         * Make a pass over the table to populate the cpus[] and
         * mem_info[] tables.
         */
        srat = acpi_map_table(srat_physaddr, ACPI_SIG_SRAT);
        error = 0;
        srat_walk_table(srat_parse_entry, &error);
        acpi_unmap_table(srat);
        srat = NULL;
        if (error || check_domains() != 0 || check_phys_avail() != 0 ||
            renumber_domains() != 0) {
                srat_physaddr = 0;
                return (-1);
        }

        return (0);
}

static void
init_mem_locality(void)
{
        int i;

        /*
         * For now, assume -1 == "no locality information for
         * this pairing.
         */
        for (i = 0; i < MAXMEMDOM * MAXMEMDOM; i++)
                vm_locality_table[i] = -1;
}

/*
 * Parse SRAT and SLIT to save proximity info. Don't do
 * anything if SRAT is not available.
 */
void
acpi_pxm_parse_tables(void)
{

        if (srat_physaddr == 0)
                return;
        if (parse_srat() < 0)
                return;
        init_mem_locality();
        (void)parse_slit();
}

/*
 * Use saved data from SRAT/SLIT to update memory locality.
 */
void
acpi_pxm_set_mem_locality(void)
{

        if (srat_physaddr == 0)
                return;
        vm_phys_register_domains(ndomain, mem_info, vm_locality_table);
}

static void
srat_walk_table(acpi_subtable_handler *handler, void *arg)
{

        acpi_walk_subtables(srat + 1, (char *)srat + srat->Header.Length,
            handler, arg);
}

/*
 * Set up per-CPU domain IDs from information saved in 'cpus' and tear down data
 * structures allocated by acpi_pxm_init().
 */
void
acpi_pxm_set_cpu_locality(void)
{
        struct cpu_info *cpu;
        struct pcpu *pc;
        u_int i;

        if (srat_physaddr == 0)
                return;
        for (i = 0; i < MAXCPU; i++) {
                if (CPU_ABSENT(i))
                        continue;
                pc = pcpu_find(i);
                KASSERT(pc != NULL, ("no pcpu data for CPU %u", i));
                cpu = cpu_get_info(pc);
                pc->pc_domain = vm_ndomains > 1 ? cpu->domain : 0;
                CPU_SET(i, &cpuset_domain[pc->pc_domain]);
                if (bootverbose)
                        printf("SRAT: CPU %u has memory domain %d\n", i,
                            pc->pc_domain);
        }
        /* XXXMJ the page is leaked. */
        pmap_unmapbios(cpus, sizeof(*cpus) * max_cpus);
        srat_physaddr = 0;
        cpus = NULL;
}

int
acpi_pxm_get_cpu_locality(int apic_id)
{
        struct cpu_info *cpu;

        cpu = cpu_find(apic_id);
        if (cpu == NULL)
                panic("SRAT: CPU with ID %u is not known", apic_id);
        return (cpu->domain);
}

/*
 * Map a _PXM value to a VM domain ID.
 *
 * Returns the domain ID, or -1 if no domain ID was found.
 */
int
acpi_map_pxm_to_vm_domainid(int pxm)
{
        int i;

        for (i = 0; i < ndomain; i++) {
                if (domain_pxm[i] == pxm)
                        return (vm_ndomains > 1 ? i : 0);
        }

        return (-1);
}

#else /* MAXMEMDOM == 1 */

int
acpi_map_pxm_to_vm_domainid(int pxm)
{

        return (-1);
}

#endif /* MAXMEMDOM > 1 */