// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  acpi.c - Architecture-Specific Low-Level ACPI Support
 *
 *  Copyright (C) 1999 VA Linux Systems
 *  Copyright (C) 1999,2000 Walt Drummond <drummond@valinux.com>
 *  Copyright (C) 2000, 2002-2003 Hewlett-Packard Co.
 *      David Mosberger-Tang <davidm@hpl.hp.com>
 *  Copyright (C) 2000 Intel Corp.
 *  Copyright (C) 2000,2001 J.I. Lee <jung-ik.lee@intel.com>
 *  Copyright (C) 2001 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
 *  Copyright (C) 2001 Jenna Hall <jenna.s.hall@intel.com>
 *  Copyright (C) 2001 Takayoshi Kochi <t-kochi@bq.jp.nec.com>
 *  Copyright (C) 2002 Erich Focht <efocht@ess.nec.de>
 *  Copyright (C) 2004 Ashok Raj <ashok.raj@intel.com>
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/irq.h>
#include <linux/acpi.h>
#include <linux/efi.h>
#include <linux/mmzone.h>
#include <linux/nodemask.h>
#include <linux/slab.h>
#include <acpi/processor.h>
#include <asm/io.h>
#include <asm/iosapic.h>
#include <asm/page.h>
#include <asm/numa.h>
#include <asm/sal.h>
#include <asm/cyclone.h>

#define PREFIX                  "ACPI: "

int acpi_lapic;
unsigned int acpi_cpei_override;
unsigned int acpi_cpei_phys_cpuid;

unsigned long acpi_wakeup_address = 0;

#define ACPI_MAX_PLATFORM_INTERRUPTS    256

/* Array to record platform interrupt vectors for generic interrupt routing. */
int platform_intr_list[ACPI_MAX_PLATFORM_INTERRUPTS] = {
        [0 ... ACPI_MAX_PLATFORM_INTERRUPTS - 1] = -1
};

enum acpi_irq_model_id acpi_irq_model = ACPI_IRQ_MODEL_IOSAPIC;

/*
 * Interrupt routing API for device drivers.  Provides interrupt vector for
 * a generic platform event.  Currently only CPEI is implemented.
 */
int acpi_request_vector(u32 int_type)
{
        int vector = -1;

        if (int_type < ACPI_MAX_PLATFORM_INTERRUPTS) {
                /* corrected platform error interrupt */
                vector = platform_intr_list[int_type];
        } else
                printk(KERN_ERR
                       "acpi_request_vector(): invalid interrupt type\n");
        return vector;
}

void __init __iomem *__acpi_map_table(unsigned long phys, unsigned long size)
{
        return __va(phys);
}

void __init __acpi_unmap_table(void __iomem *map, unsigned long size)
{
}

/* --------------------------------------------------------------------------
                            Boot-time Table Parsing
   -------------------------------------------------------------------------- */

static int available_cpus __initdata;
struct acpi_table_madt *acpi_madt __initdata;
static u8 has_8259;

static int __init
acpi_parse_lapic_addr_ovr(union acpi_subtable_headers * header,
                          const unsigned long end)
{
        struct acpi_madt_local_apic_override *lapic;

        lapic = (struct acpi_madt_local_apic_override *)header;

        if (BAD_MADT_ENTRY(lapic, end))
                return -EINVAL;

        if (lapic->address) {
                iounmap(ipi_base_addr);
                ipi_base_addr = ioremap(lapic->address, 0);
        }
        return 0;
}

static int __init
acpi_parse_lsapic(union acpi_subtable_headers *header, const unsigned long end)
{
        struct acpi_madt_local_sapic *lsapic;

        lsapic = (struct acpi_madt_local_sapic *)header;

        /*Skip BAD_MADT_ENTRY check, as lsapic size could vary */

        if (lsapic->lapic_flags & ACPI_MADT_ENABLED) {
#ifdef CONFIG_SMP
                smp_boot_data.cpu_phys_id[available_cpus] =
                    (lsapic->id << 8) | lsapic->eid;
#endif
                ++available_cpus;
        }

        total_cpus++;
        return 0;
}

static int __init
acpi_parse_lapic_nmi(union acpi_subtable_headers * header, const unsigned long end)
{
        struct acpi_madt_local_apic_nmi *lacpi_nmi;

        lacpi_nmi = (struct acpi_madt_local_apic_nmi *)header;

        if (BAD_MADT_ENTRY(lacpi_nmi, end))
                return -EINVAL;

        /* TBD: Support lapic_nmi entries */
        return 0;
}

static int __init
acpi_parse_iosapic(union acpi_subtable_headers * header, const unsigned long end)
{
        struct acpi_madt_io_sapic *iosapic;

        iosapic = (struct acpi_madt_io_sapic *)header;

        if (BAD_MADT_ENTRY(iosapic, end))
                return -EINVAL;

        return iosapic_init(iosapic->address, iosapic->global_irq_base);
}

static unsigned int __initdata acpi_madt_rev;

static int __init
acpi_parse_plat_int_src(union acpi_subtable_headers * header,
                        const unsigned long end)
{
        struct acpi_madt_interrupt_source *plintsrc;
        int vector;

        plintsrc = (struct acpi_madt_interrupt_source *)header;

        if (BAD_MADT_ENTRY(plintsrc, end))
                return -EINVAL;

        /*
         * Get vector assignment for this interrupt, set attributes,
         * and program the IOSAPIC routing table.
         */
        vector = iosapic_register_platform_intr(plintsrc->type,
                                                plintsrc->global_irq,
                                                plintsrc->io_sapic_vector,
                                                plintsrc->eid,
                                                plintsrc->id,
                                                ((plintsrc->inti_flags & ACPI_MADT_POLARITY_MASK) ==
                                                 ACPI_MADT_POLARITY_ACTIVE_HIGH) ?
                                                IOSAPIC_POL_HIGH : IOSAPIC_POL_LOW,
                                                ((plintsrc->inti_flags & ACPI_MADT_TRIGGER_MASK) ==
                                                 ACPI_MADT_TRIGGER_EDGE) ?
                                                IOSAPIC_EDGE : IOSAPIC_LEVEL);

        platform_intr_list[plintsrc->type] = vector;
        if (acpi_madt_rev > 1) {
                acpi_cpei_override = plintsrc->flags & ACPI_MADT_CPEI_OVERRIDE;
        }

        /*
         * Save the physical id, so we can check when its being removed
         */
        acpi_cpei_phys_cpuid = ((plintsrc->id << 8) | (plintsrc->eid)) & 0xffff;

        return 0;
}

#ifdef CONFIG_HOTPLUG_CPU
unsigned int can_cpei_retarget(void)
{
        extern int cpe_vector;
        extern unsigned int force_cpei_retarget;

        /*
         * Only if CPEI is supported and the override flag
         * is present, otherwise return that its re-targettable
         * if we are in polling mode.
         */
        if (cpe_vector > 0) {
                if (acpi_cpei_override || force_cpei_retarget)
                        return 1;
                else
                        return 0;
        }
        return 1;
}

unsigned int is_cpu_cpei_target(unsigned int cpu)
{
        unsigned int logical_id;

        logical_id = cpu_logical_id(acpi_cpei_phys_cpuid);

        if (logical_id == cpu)
                return 1;
        else
                return 0;
}

void set_cpei_target_cpu(unsigned int cpu)
{
        acpi_cpei_phys_cpuid = cpu_physical_id(cpu);
}
#endif

unsigned int get_cpei_target_cpu(void)
{
        return acpi_cpei_phys_cpuid;
}

static int __init
acpi_parse_int_src_ovr(union acpi_subtable_headers * header,
                       const unsigned long end)
{
        struct acpi_madt_interrupt_override *p;

        p = (struct acpi_madt_interrupt_override *)header;

        if (BAD_MADT_ENTRY(p, end))
                return -EINVAL;

        iosapic_override_isa_irq(p->source_irq, p->global_irq,
                                 ((p->inti_flags & ACPI_MADT_POLARITY_MASK) ==
                                  ACPI_MADT_POLARITY_ACTIVE_LOW) ?
                                 IOSAPIC_POL_LOW : IOSAPIC_POL_HIGH,
                                 ((p->inti_flags & ACPI_MADT_TRIGGER_MASK) ==
                                 ACPI_MADT_TRIGGER_LEVEL) ?
                                 IOSAPIC_LEVEL : IOSAPIC_EDGE);
        return 0;
}

static int __init
acpi_parse_nmi_src(union acpi_subtable_headers * header, const unsigned long end)
{
        struct acpi_madt_nmi_source *nmi_src;

        nmi_src = (struct acpi_madt_nmi_source *)header;

        if (BAD_MADT_ENTRY(nmi_src, end))
                return -EINVAL;

        /* TBD: Support nimsrc entries */
        return 0;
}

static void __init acpi_madt_oem_check(char *oem_id, char *oem_table_id)
{
        if (!strncmp(oem_id, "IBM", 3) && (!strncmp(oem_table_id, "SERMOW", 6))) {

                /*
                 * Unfortunately ITC_DRIFT is not yet part of the
                 * official SAL spec, so the ITC_DRIFT bit is not
                 * set by the BIOS on this hardware.
                 */
                sal_platform_features |= IA64_SAL_PLATFORM_FEATURE_ITC_DRIFT;

                cyclone_setup();
        }
}

static int __init acpi_parse_madt(struct acpi_table_header *table)
{
        acpi_madt = (struct acpi_table_madt *)table;

        acpi_madt_rev = acpi_madt->header.revision;

        /* remember the value for reference after free_initmem() */
#ifdef CONFIG_ITANIUM
        has_8259 = 1;           /* Firmware on old Itanium systems is broken */
#else
        has_8259 = acpi_madt->flags & ACPI_MADT_PCAT_COMPAT;
#endif
        iosapic_system_init(has_8259);

        /* Get base address of IPI Message Block */

        if (acpi_madt->address)
                ipi_base_addr = ioremap(acpi_madt->address, 0);

        printk(KERN_INFO PREFIX "Local APIC address %p\n", ipi_base_addr);

        acpi_madt_oem_check(acpi_madt->header.oem_id,
                            acpi_madt->header.oem_table_id);

        return 0;
}

#ifdef CONFIG_ACPI_NUMA

#undef SLIT_DEBUG

#define PXM_FLAG_LEN ((MAX_PXM_DOMAINS + 1)/32)

static int __initdata srat_num_cpus;    /* number of cpus */
static u32 pxm_flag[PXM_FLAG_LEN];
#define pxm_bit_set(bit)        (set_bit(bit,(void *)pxm_flag))
#define pxm_bit_test(bit)       (test_bit(bit,(void *)pxm_flag))
static struct acpi_table_slit __initdata *slit_table;
cpumask_t early_cpu_possible_map = CPU_MASK_NONE;

static int __init
get_processor_proximity_domain(struct acpi_srat_cpu_affinity *pa)
{
        int pxm;

        pxm = pa->proximity_domain_lo;
        if (acpi_srat_revision >= 2)
                pxm += pa->proximity_domain_hi[0] << 8;
        return pxm;
}

static int __init
get_memory_proximity_domain(struct acpi_srat_mem_affinity *ma)
{
        int pxm;

        pxm = ma->proximity_domain;
        if (acpi_srat_revision <= 1)
                pxm &= 0xff;

        return pxm;
}

/*
 * ACPI 2.0 SLIT (System Locality Information Table)
 * http://devresource.hp.com/devresource/Docs/TechPapers/IA64/slit.pdf
 */
void __init acpi_numa_slit_init(struct acpi_table_slit *slit)
{
        u32 len;

        len = sizeof(struct acpi_table_header) + 8
            + slit->locality_count * slit->locality_count;
        if (slit->header.length != len) {
                printk(KERN_ERR
                       "ACPI 2.0 SLIT: size mismatch: %d expected, %d actual\n",
                       len, slit->header.length);
                return;
        }
        slit_table = slit;
}

void __init
acpi_numa_processor_affinity_init(struct acpi_srat_cpu_affinity *pa)
{
        int pxm;

        if (!(pa->flags & ACPI_SRAT_CPU_ENABLED))
                return;

        if (srat_num_cpus >= ARRAY_SIZE(node_cpuid)) {
                printk_once(KERN_WARNING
                            "node_cpuid[%ld] is too small, may not be able to use all cpus\n",
                            ARRAY_SIZE(node_cpuid));
                return;
        }
        pxm = get_processor_proximity_domain(pa);

        /* record this node in proximity bitmap */
        pxm_bit_set(pxm);

        node_cpuid[srat_num_cpus].phys_id =
            (pa->apic_id << 8) | (pa->local_sapic_eid);
        /* nid should be overridden as logical node id later */
        node_cpuid[srat_num_cpus].nid = pxm;
        cpumask_set_cpu(srat_num_cpus, &early_cpu_possible_map);
        srat_num_cpus++;
}

int __init
acpi_numa_memory_affinity_init(struct acpi_srat_mem_affinity *ma)
{
        unsigned long paddr, size;
        int pxm;
        struct node_memblk_s *p, *q, *pend;

        pxm = get_memory_proximity_domain(ma);

        /* fill node memory chunk structure */
        paddr = ma->base_address;
        size = ma->length;

        /* Ignore disabled entries */
        if (!(ma->flags & ACPI_SRAT_MEM_ENABLED))
                return -1;

        if (num_node_memblks >= NR_NODE_MEMBLKS) {
                pr_err("NUMA: too many memblk ranges\n");
                return -EINVAL;
        }

        /* record this node in proximity bitmap */
        pxm_bit_set(pxm);

        /* Insertion sort based on base address */
        pend = &node_memblk[num_node_memblks];
        for (p = &node_memblk[0]; p < pend; p++) {
                if (paddr < p->start_paddr)
                        break;
        }
        if (p < pend) {
                for (q = pend - 1; q >= p; q--)
                        *(q + 1) = *q;
        }
        p->start_paddr = paddr;
        p->size = size;
        p->nid = pxm;
        num_node_memblks++;
        return 0;
}

void __init acpi_numa_fixup(void)
{
        int i, j, node_from, node_to;

        /* If there's no SRAT, fix the phys_id and mark node 0 online */
        if (srat_num_cpus == 0) {
                node_set_online(0);
                node_cpuid[0].phys_id = hard_smp_processor_id();
                return;
        }

        /*
         * MCD - This can probably be dropped now.  No need for pxm ID to node ID
         * mapping with sparse node numbering iff MAX_PXM_DOMAINS <= MAX_NUMNODES.
         */
        nodes_clear(node_online_map);
        for (i = 0; i < MAX_PXM_DOMAINS; i++) {
                if (pxm_bit_test(i)) {
                        int nid = acpi_map_pxm_to_node(i);
                        node_set_online(nid);
                }
        }

        /* set logical node id in memory chunk structure */
        for (i = 0; i < num_node_memblks; i++)
                node_memblk[i].nid = pxm_to_node(node_memblk[i].nid);

        /* assign memory bank numbers for each chunk on each node */
        for_each_online_node(i) {
                int bank;

                bank = 0;
                for (j = 0; j < num_node_memblks; j++)
                        if (node_memblk[j].nid == i)
                                node_memblk[j].bank = bank++;
        }

        /* set logical node id in cpu structure */
        for_each_possible_early_cpu(i)
                node_cpuid[i].nid = pxm_to_node(node_cpuid[i].nid);

        printk(KERN_INFO "Number of logical nodes in system = %d\n",
               num_online_nodes());
        printk(KERN_INFO "Number of memory chunks in system = %d\n",
               num_node_memblks);

        if (!slit_table) {
                for (i = 0; i < MAX_NUMNODES; i++)
                        for (j = 0; j < MAX_NUMNODES; j++)
                                slit_distance(i, j) = i == j ?
                                        LOCAL_DISTANCE : REMOTE_DISTANCE;
                return;
        }

        memset(numa_slit, -1, sizeof(numa_slit));
        for (i = 0; i < slit_table->locality_count; i++) {
                if (!pxm_bit_test(i))
                        continue;
                node_from = pxm_to_node(i);
                for (j = 0; j < slit_table->locality_count; j++) {
                        if (!pxm_bit_test(j))
                                continue;
                        node_to = pxm_to_node(j);
                        slit_distance(node_from, node_to) =
                            slit_table->entry[i * slit_table->locality_count + j];
                }
        }

#ifdef SLIT_DEBUG
        printk("ACPI 2.0 SLIT locality table:\n");
        for_each_online_node(i) {
                for_each_online_node(j)
                    printk("%03d ", node_distance(i, j));
                printk("\n");
        }
#endif
}
#endif                          /* CONFIG_ACPI_NUMA */

/*
 * success: return IRQ number (>=0)
 * failure: return < 0
 */
int acpi_register_gsi(struct device *dev, u32 gsi, int triggering, int polarity)
{
        if (acpi_irq_model == ACPI_IRQ_MODEL_PLATFORM)
                return gsi;

        if (has_8259 && gsi < 16)
                return isa_irq_to_vector(gsi);

        return iosapic_register_intr(gsi,
                                     (polarity ==
                                      ACPI_ACTIVE_HIGH) ? IOSAPIC_POL_HIGH :
                                     IOSAPIC_POL_LOW,
                                     (triggering ==
                                      ACPI_EDGE_SENSITIVE) ? IOSAPIC_EDGE :
                                     IOSAPIC_LEVEL);
}
EXPORT_SYMBOL_GPL(acpi_register_gsi);

void acpi_unregister_gsi(u32 gsi)
{
        if (acpi_irq_model == ACPI_IRQ_MODEL_PLATFORM)
                return;

        if (has_8259 && gsi < 16)
                return;

        iosapic_unregister_intr(gsi);
}
EXPORT_SYMBOL_GPL(acpi_unregister_gsi);

static int __init acpi_parse_fadt(struct acpi_table_header *table)
{
        struct acpi_table_header *fadt_header;
        struct acpi_table_fadt *fadt;

        fadt_header = (struct acpi_table_header *)table;
        if (fadt_header->revision != 3)
                return -ENODEV; /* Only deal with ACPI 2.0 FADT */

        fadt = (struct acpi_table_fadt *)fadt_header;

        acpi_register_gsi(NULL, fadt->sci_interrupt, ACPI_LEVEL_SENSITIVE,
                                 ACPI_ACTIVE_LOW);
        return 0;
}

int __init early_acpi_boot_init(void)
{
        int ret;

        /*
         * do a partial walk of MADT to determine how many CPUs
         * we have including offline CPUs
         */
        if (acpi_table_parse(ACPI_SIG_MADT, acpi_parse_madt)) {
                printk(KERN_ERR PREFIX "Can't find MADT\n");
                return 0;
        }

        ret = acpi_table_parse_madt(ACPI_MADT_TYPE_LOCAL_SAPIC,
                acpi_parse_lsapic, NR_CPUS);
        if (ret < 1)
                printk(KERN_ERR PREFIX
                       "Error parsing MADT - no LAPIC entries\n");
        else
                acpi_lapic = 1;

#ifdef CONFIG_SMP
        if (available_cpus == 0) {
                printk(KERN_INFO "ACPI: Found 0 CPUS; assuming 1\n");
                printk(KERN_INFO "CPU 0 (0x%04x)", hard_smp_processor_id());
                smp_boot_data.cpu_phys_id[available_cpus] =
                    hard_smp_processor_id();
                available_cpus = 1;     /* We've got at least one of these, no? */
        }
        smp_boot_data.cpu_count = available_cpus;
#endif
        /* Make boot-up look pretty */
        printk(KERN_INFO "%d CPUs available, %d CPUs total\n", available_cpus,
               total_cpus);

        return 0;
}

int __init acpi_boot_init(void)
{

        /*
         * MADT
         * ----
         * Parse the Multiple APIC Description Table (MADT), if exists.
         * Note that this table provides platform SMP configuration
         * information -- the successor to MPS tables.
         */

        if (acpi_table_parse(ACPI_SIG_MADT, acpi_parse_madt)) {
                printk(KERN_ERR PREFIX "Can't find MADT\n");
                goto skip_madt;
        }

        /* Local APIC */

        if (acpi_table_parse_madt
            (ACPI_MADT_TYPE_LOCAL_APIC_OVERRIDE, acpi_parse_lapic_addr_ovr, 0) < 0)
                printk(KERN_ERR PREFIX
                       "Error parsing LAPIC address override entry\n");

        if (acpi_table_parse_madt(ACPI_MADT_TYPE_LOCAL_APIC_NMI, acpi_parse_lapic_nmi, 0)
            < 0)
                printk(KERN_ERR PREFIX "Error parsing LAPIC NMI entry\n");

        /* I/O APIC */

        if (acpi_table_parse_madt
            (ACPI_MADT_TYPE_IO_SAPIC, acpi_parse_iosapic, NR_IOSAPICS) < 1) {
                printk(KERN_ERR PREFIX
                       "Error parsing MADT - no IOSAPIC entries\n");
        }

        /* System-Level Interrupt Routing */

        if (acpi_table_parse_madt
            (ACPI_MADT_TYPE_INTERRUPT_SOURCE, acpi_parse_plat_int_src,
             ACPI_MAX_PLATFORM_INTERRUPTS) < 0)
                printk(KERN_ERR PREFIX
                       "Error parsing platform interrupt source entry\n");

        if (acpi_table_parse_madt
            (ACPI_MADT_TYPE_INTERRUPT_OVERRIDE, acpi_parse_int_src_ovr, 0) < 0)
                printk(KERN_ERR PREFIX
                       "Error parsing interrupt source overrides entry\n");

        if (acpi_table_parse_madt(ACPI_MADT_TYPE_NMI_SOURCE, acpi_parse_nmi_src, 0) < 0)
                printk(KERN_ERR PREFIX "Error parsing NMI SRC entry\n");
      skip_madt:

        /*
         * FADT says whether a legacy keyboard controller is present.
         * The FADT also contains an SCI_INT line, by which the system
         * gets interrupts such as power and sleep buttons.  If it's not
         * on a Legacy interrupt, it needs to be setup.
         */
        if (acpi_table_parse(ACPI_SIG_FADT, acpi_parse_fadt))
                printk(KERN_ERR PREFIX "Can't find FADT\n");

#ifdef CONFIG_ACPI_NUMA
#ifdef CONFIG_SMP
        if (srat_num_cpus == 0) {
                int cpu, i = 1;
                for (cpu = 0; cpu < smp_boot_data.cpu_count; cpu++)
                        if (smp_boot_data.cpu_phys_id[cpu] !=
                            hard_smp_processor_id())
                                node_cpuid[i++].phys_id =
                                    smp_boot_data.cpu_phys_id[cpu];
        }
#endif
        build_cpu_to_node_map();
#endif
        return 0;
}

int acpi_gsi_to_irq(u32 gsi, unsigned int *irq)
{
        int tmp;

        if (has_8259 && gsi < 16)
                *irq = isa_irq_to_vector(gsi);
        else {
                tmp = gsi_to_irq(gsi);
                if (tmp == -1)
                        return -1;
                *irq = tmp;
        }
        return 0;
}

int acpi_isa_irq_to_gsi(unsigned isa_irq, u32 *gsi)
{
        if (isa_irq >= 16)
                return -1;
        *gsi = isa_irq;
        return 0;
}

/*
 *  ACPI based hotplug CPU support
 */
#ifdef CONFIG_ACPI_HOTPLUG_CPU
int acpi_map_cpu2node(acpi_handle handle, int cpu, int physid)
{
#ifdef CONFIG_ACPI_NUMA
        /*
         * We don't have cpu-only-node hotadd. But if the system equips
         * SRAT table, pxm is already found and node is ready.
         * So, just pxm_to_nid(pxm) is OK.
         * This code here is for the system which doesn't have full SRAT
         * table for possible cpus.
         */
        node_cpuid[cpu].phys_id = physid;
        node_cpuid[cpu].nid = acpi_get_node(handle);
#endif
        return 0;
}

int additional_cpus __initdata = -1;

static __init int setup_additional_cpus(char *s)
{
        if (s)
                additional_cpus = simple_strtol(s, NULL, 0);

        return 0;
}

early_param("additional_cpus", setup_additional_cpus);

/*
 * cpu_possible_mask should be static, it cannot change as CPUs
 * are onlined, or offlined. The reason is per-cpu data-structures
 * are allocated by some modules at init time, and dont expect to
 * do this dynamically on cpu arrival/departure.
 * cpu_present_mask on the other hand can change dynamically.
 * In case when cpu_hotplug is not compiled, then we resort to current
 * behaviour, which is cpu_possible == cpu_present.
 * - Ashok Raj
 *
 * Three ways to find out the number of additional hotplug CPUs:
 * - If the BIOS specified disabled CPUs in ACPI/mptables use that.
 * - The user can overwrite it with additional_cpus=NUM
 * - Otherwise don't reserve additional CPUs.
 */
__init void prefill_possible_map(void)
{
        int i;
        int possible, disabled_cpus;

        disabled_cpus = total_cpus - available_cpus;

        if (additional_cpus == -1) {
                if (disabled_cpus > 0)
                        additional_cpus = disabled_cpus;
                else
                        additional_cpus = 0;
        }

        possible = available_cpus + additional_cpus;

        if (possible > nr_cpu_ids)
                possible = nr_cpu_ids;

        printk(KERN_INFO "SMP: Allowing %d CPUs, %d hotplug CPUs\n",
                possible, max((possible - available_cpus), 0));

        for (i = 0; i < possible; i++)
                set_cpu_possible(i, true);
}

static int _acpi_map_lsapic(acpi_handle handle, int physid, int *pcpu)
{
        cpumask_t tmp_map;
        int cpu;

        cpumask_complement(&tmp_map, cpu_present_mask);
        cpu = cpumask_first(&tmp_map);
        if (cpu >= nr_cpu_ids)
                return -EINVAL;

        acpi_map_cpu2node(handle, cpu, physid);

        set_cpu_present(cpu, true);
        ia64_cpu_to_sapicid[cpu] = physid;

        acpi_processor_set_pdc(handle);

        *pcpu = cpu;
        return (0);
}

/* wrapper to silence section mismatch warning */
int __ref acpi_map_cpu(acpi_handle handle, phys_cpuid_t physid, u32 acpi_id,
                       int *pcpu)
{
        return _acpi_map_lsapic(handle, physid, pcpu);
}
EXPORT_SYMBOL(acpi_map_cpu);

int acpi_unmap_cpu(int cpu)
{
        ia64_cpu_to_sapicid[cpu] = -1;
        set_cpu_present(cpu, false);

#ifdef CONFIG_ACPI_NUMA
        /* NUMA specific cleanup's */
#endif

        return (0);
}
EXPORT_SYMBOL(acpi_unmap_cpu);
#endif                          /* CONFIG_ACPI_HOTPLUG_CPU */

#ifdef CONFIG_ACPI_NUMA
static acpi_status acpi_map_iosapic(acpi_handle handle, u32 depth,
                                    void *context, void **ret)
{
        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
        union acpi_object *obj;
        struct acpi_madt_io_sapic *iosapic;
        unsigned int gsi_base;
        int node;

        /* Only care about objects w/ a method that returns the MADT */
        if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
                return AE_OK;

        if (!buffer.length || !buffer.pointer)
                return AE_OK;

        obj = buffer.pointer;
        if (obj->type != ACPI_TYPE_BUFFER ||
            obj->buffer.length < sizeof(*iosapic)) {
                kfree(buffer.pointer);
                return AE_OK;
        }

        iosapic = (struct acpi_madt_io_sapic *)obj->buffer.pointer;

        if (iosapic->header.type != ACPI_MADT_TYPE_IO_SAPIC) {
                kfree(buffer.pointer);
                return AE_OK;
        }

        gsi_base = iosapic->global_irq_base;

        kfree(buffer.pointer);

        /* OK, it's an IOSAPIC MADT entry; associate it with a node */
        node = acpi_get_node(handle);
        if (node == NUMA_NO_NODE || !node_online(node) ||
            cpumask_empty(cpumask_of_node(node)))
                return AE_OK;

        /* We know a gsi to node mapping! */
        map_iosapic_to_node(gsi_base, node);
        return AE_OK;
}

static int __init
acpi_map_iosapics (void)
{
        acpi_get_devices(NULL, acpi_map_iosapic, NULL, NULL);
        return 0;
}

fs_initcall(acpi_map_iosapics);
#endif                          /* CONFIG_ACPI_NUMA */

int __ref acpi_register_ioapic(acpi_handle handle, u64 phys_addr, u32 gsi_base)
{
        int err;

        if ((err = iosapic_init(phys_addr, gsi_base)))
                return err;

#ifdef CONFIG_ACPI_NUMA
        acpi_map_iosapic(handle, 0, NULL, NULL);
#endif                          /* CONFIG_ACPI_NUMA */

        return 0;
}

EXPORT_SYMBOL(acpi_register_ioapic);

int acpi_unregister_ioapic(acpi_handle handle, u32 gsi_base)
{
        return iosapic_remove(gsi_base);
}

EXPORT_SYMBOL(acpi_unregister_ioapic);

/*
 * acpi_suspend_lowlevel() - save kernel state and suspend.
 *
 * TBD when when IA64 starts to support suspend...
 */
int acpi_suspend_lowlevel(void) { return 0; }