/*
 *  64-bit pSeries and RS/6000 setup code.
 *
 *  Copyright (C) 1995  Linus Torvalds
 *  Adapted from 'alpha' version by Gary Thomas
 *  Modified by Cort Dougan (cort@cs.nmt.edu)
 *  Modified by PPC64 Team, IBM Corp
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

/*
 * bootup setup stuff..
 */

#include <linux/cpu.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/user.h>
#include <linux/tty.h>
#include <linux/major.h>
#include <linux/interrupt.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/console.h>
#include <linux/pci.h>
#include <linux/utsname.h>
#include <linux/adb.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/irq.h>
#include <linux/seq_file.h>
#include <linux/root_dev.h>

#include <asm/mmu.h>
#include <asm/processor.h>
#include <asm/io.h>
#include <asm/pgtable.h>
#include <asm/prom.h>
#include <asm/rtas.h>
#include <asm/pci-bridge.h>
#include <asm/iommu.h>
#include <asm/dma.h>
#include <asm/machdep.h>
#include <asm/irq.h>
#include <asm/time.h>
#include <asm/nvram.h>
#include "xics.h"
#include <asm/pmc.h>
#include <asm/mpic.h>
#include <asm/ppc-pci.h>
#include <asm/i8259.h>
#include <asm/udbg.h>
#include <asm/smp.h>
#include <asm/firmware.h>
#include <asm/eeh.h>
#include <asm/pSeries_reconfig.h>

#include "plpar_wrappers.h"
#include "pseries.h"

int CMO_PrPSP = -1;
int CMO_SecPSP = -1;
unsigned long CMO_PageSize = (ASM_CONST(1) << IOMMU_PAGE_SHIFT);
EXPORT_SYMBOL(CMO_PageSize);

int fwnmi_active;  /* TRUE if an FWNMI handler is present */

static void pseries_shared_idle_sleep(void);
static void pseries_dedicated_idle_sleep(void);

static struct device_node *pSeries_mpic_node;

static void pSeries_show_cpuinfo(struct seq_file *m)
{
        struct device_node *root;
        const char *model = "";

        root = of_find_node_by_path("/");
        if (root)
                model = of_get_property(root, "model", NULL);
        seq_printf(m, "machine\t\t: CHRP %s\n", model);
        of_node_put(root);
}

/* Initialize firmware assisted non-maskable interrupts if
 * the firmware supports this feature.
 */
static void __init fwnmi_init(void)
{
        unsigned long system_reset_addr, machine_check_addr;

        int ibm_nmi_register = rtas_token("ibm,nmi-register");
        if (ibm_nmi_register == RTAS_UNKNOWN_SERVICE)
                return;

        /* If the kernel's not linked at zero we point the firmware at low
         * addresses anyway, and use a trampoline to get to the real code. */
        system_reset_addr  = __pa(system_reset_fwnmi) - PHYSICAL_START;
        machine_check_addr = __pa(machine_check_fwnmi) - PHYSICAL_START;

        if (0 == rtas_call(ibm_nmi_register, 2, 1, NULL, system_reset_addr,
                                machine_check_addr))
                fwnmi_active = 1;
}

static void pseries_8259_cascade(unsigned int irq, struct irq_desc *desc)
{
        struct irq_chip *chip = irq_desc_get_chip(desc);
        unsigned int cascade_irq = i8259_irq();

        if (cascade_irq != NO_IRQ)
                generic_handle_irq(cascade_irq);

        chip->irq_eoi(&desc->irq_data);
}

static void __init pseries_setup_i8259_cascade(void)
{
        struct device_node *np, *old, *found = NULL;
        unsigned int cascade;
        const u32 *addrp;
        unsigned long intack = 0;
        int naddr;

        for_each_node_by_type(np, "interrupt-controller") {
                if (of_device_is_compatible(np, "chrp,iic")) {
                        found = np;
                        break;
                }
        }

        if (found == NULL) {
                printk(KERN_DEBUG "pic: no ISA interrupt controller\n");
                return;
        }

        cascade = irq_of_parse_and_map(found, 0);
        if (cascade == NO_IRQ) {
                printk(KERN_ERR "pic: failed to map cascade interrupt");
                return;
        }
        pr_debug("pic: cascade mapped to irq %d\n", cascade);

        for (old = of_node_get(found); old != NULL ; old = np) {
                np = of_get_parent(old);
                of_node_put(old);
                if (np == NULL)
                        break;
                if (strcmp(np->name, "pci") != 0)
                        continue;
                addrp = of_get_property(np, "8259-interrupt-acknowledge", NULL);
                if (addrp == NULL)
                        continue;
                naddr = of_n_addr_cells(np);
                intack = addrp[naddr-1];
                if (naddr > 1)
                        intack |= ((unsigned long)addrp[naddr-2]) << 32;
        }
        if (intack)
                printk(KERN_DEBUG "pic: PCI 8259 intack at 0x%016lx\n", intack);
        i8259_init(found, intack);
        of_node_put(found);
        irq_set_chained_handler(cascade, pseries_8259_cascade);
}

static void __init pseries_mpic_init_IRQ(void)
{
        struct device_node *np;
        const unsigned int *opprop;
        unsigned long openpic_addr = 0;
        int naddr, n, i, opplen;
        struct mpic *mpic;

        np = of_find_node_by_path("/");
        naddr = of_n_addr_cells(np);
        opprop = of_get_property(np, "platform-open-pic", &opplen);
        if (opprop != 0) {
                openpic_addr = of_read_number(opprop, naddr);
                printk(KERN_DEBUG "OpenPIC addr: %lx\n", openpic_addr);
        }
        of_node_put(np);

        BUG_ON(openpic_addr == 0);

        /* Setup the openpic driver */
        mpic = mpic_alloc(pSeries_mpic_node, openpic_addr,
                          MPIC_PRIMARY,
                          16, 250, /* isu size, irq count */
                          " MPIC     ");
        BUG_ON(mpic == NULL);

        /* Add ISUs */
        opplen /= sizeof(u32);
        for (n = 0, i = naddr; i < opplen; i += naddr, n++) {
                unsigned long isuaddr = of_read_number(opprop + i, naddr);
                mpic_assign_isu(mpic, n, isuaddr);
        }

        /* All ISUs are setup, complete initialization */
        mpic_init(mpic);

        /* Look for cascade */
        pseries_setup_i8259_cascade();
}

static void __init pseries_xics_init_IRQ(void)
{
        xics_init_IRQ();
        pseries_setup_i8259_cascade();
}

static void pseries_lpar_enable_pmcs(void)
{
        unsigned long set, reset;

        set = 1UL << 63;
        reset = 0;
        plpar_hcall_norets(H_PERFMON, set, reset);
}

static void __init pseries_discover_pic(void)
{
        struct device_node *np;
        const char *typep;

        for (np = NULL; (np = of_find_node_by_name(np,
                                                   "interrupt-controller"));) {
                typep = of_get_property(np, "compatible", NULL);
                if (strstr(typep, "open-pic")) {
                        pSeries_mpic_node = of_node_get(np);
                        ppc_md.init_IRQ       = pseries_mpic_init_IRQ;
                        ppc_md.get_irq        = mpic_get_irq;
                        setup_kexec_cpu_down_mpic();
                        smp_init_pseries_mpic();
                        return;
                } else if (strstr(typep, "ppc-xicp")) {
                        ppc_md.init_IRQ       = pseries_xics_init_IRQ;
                        setup_kexec_cpu_down_xics();
                        smp_init_pseries_xics();
                        return;
                }
        }
        printk(KERN_ERR "pSeries_discover_pic: failed to recognize"
               " interrupt-controller\n");
}

static int pci_dn_reconfig_notifier(struct notifier_block *nb, unsigned long action, void *node)
{
        struct device_node *np = node;
        struct pci_dn *pci = NULL;
        int err = NOTIFY_OK;

        switch (action) {
        case PSERIES_RECONFIG_ADD:
                pci = np->parent->data;
                if (pci)
                        update_dn_pci_info(np, pci->phb);
                break;
        default:
                err = NOTIFY_DONE;
                break;
        }
        return err;
}

static struct notifier_block pci_dn_reconfig_nb = {
        .notifier_call = pci_dn_reconfig_notifier,
};

#ifdef CONFIG_VIRT_CPU_ACCOUNTING
/*
 * Allocate space for the dispatch trace log for all possible cpus
 * and register the buffers with the hypervisor.  This is used for
 * computing time stolen by the hypervisor.
 */
static int alloc_dispatch_logs(void)
{
        int cpu, ret;
        struct paca_struct *pp;
        struct dtl_entry *dtl;
        struct kmem_cache *dtl_cache;

        if (!firmware_has_feature(FW_FEATURE_SPLPAR))
                return 0;

        dtl_cache = kmem_cache_create("dtl", DISPATCH_LOG_BYTES,
                                                DISPATCH_LOG_BYTES, 0, NULL);
        if (!dtl_cache) {
                pr_warn("Failed to create dispatch trace log buffer cache\n");
                pr_warn("Stolen time statistics will be unreliable\n");
                return 0;
        }

        for_each_possible_cpu(cpu) {
                pp = &paca[cpu];
                dtl = kmem_cache_alloc(dtl_cache, GFP_KERNEL);
                if (!dtl) {
                        pr_warn("Failed to allocate dispatch trace log for cpu %d\n",
                                cpu);
                        pr_warn("Stolen time statistics will be unreliable\n");
                        break;
                }

                pp->dtl_ridx = 0;
                pp->dispatch_log = dtl;
                pp->dispatch_log_end = dtl + N_DISPATCH_LOG;
                pp->dtl_curr = dtl;
        }

        /* Register the DTL for the current (boot) cpu */
        dtl = get_paca()->dispatch_log;
        get_paca()->dtl_ridx = 0;
        get_paca()->dtl_curr = dtl;
        get_paca()->lppaca_ptr->dtl_idx = 0;

        /* hypervisor reads buffer length from this field */
        dtl->enqueue_to_dispatch_time = DISPATCH_LOG_BYTES;
        ret = register_dtl(hard_smp_processor_id(), __pa(dtl));
        if (ret)
                pr_warn("DTL registration failed for boot cpu %d (%d)\n",
                        smp_processor_id(), ret);
        get_paca()->lppaca_ptr->dtl_enable_mask = 2;

        return 0;
}

early_initcall(alloc_dispatch_logs);
#endif /* CONFIG_VIRT_CPU_ACCOUNTING */

static void __init pSeries_setup_arch(void)
{
        /* Discover PIC type and setup ppc_md accordingly */
        pseries_discover_pic();

        /* openpic global configuration register (64-bit format). */
        /* openpic Interrupt Source Unit pointer (64-bit format). */
        /* python0 facility area (mmio) (64-bit format) REAL address. */

        /* init to some ~sane value until calibrate_delay() runs */
        loops_per_jiffy = 50000000;

        fwnmi_init();

        /* Find and initialize PCI host bridges */
        init_pci_config_tokens();
        find_and_init_phbs();
        pSeries_reconfig_notifier_register(&pci_dn_reconfig_nb);
        eeh_init();

        pSeries_nvram_init();

        /* Choose an idle loop */
        if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
                vpa_init(boot_cpuid);
                if (get_lppaca()->shared_proc) {
                        printk(KERN_DEBUG "Using shared processor idle loop\n");
                        ppc_md.power_save = pseries_shared_idle_sleep;
                } else {
                        printk(KERN_DEBUG "Using dedicated idle loop\n");
                        ppc_md.power_save = pseries_dedicated_idle_sleep;
                }
        } else {
                printk(KERN_DEBUG "Using default idle loop\n");
        }

        if (firmware_has_feature(FW_FEATURE_LPAR))
                ppc_md.enable_pmcs = pseries_lpar_enable_pmcs;
        else
                ppc_md.enable_pmcs = power4_enable_pmcs;
}

static int __init pSeries_init_panel(void)
{
        /* Manually leave the kernel version on the panel. */
        ppc_md.progress("Linux ppc64\n", 0);
        ppc_md.progress(init_utsname()->version, 0);

        return 0;
}
machine_arch_initcall(pseries, pSeries_init_panel);

static int pseries_set_dabr(unsigned long dabr)
{
        return plpar_hcall_norets(H_SET_DABR, dabr);
}

static int pseries_set_xdabr(unsigned long dabr)
{
        /* We want to catch accesses from kernel and userspace */
        return plpar_hcall_norets(H_SET_XDABR, dabr,
                        H_DABRX_KERNEL | H_DABRX_USER);
}

#define CMO_CHARACTERISTICS_TOKEN 44
#define CMO_MAXLENGTH 1026

/**
 * fw_cmo_feature_init - FW_FEATURE_CMO is not stored in ibm,hypertas-functions,
 * handle that here. (Stolen from parse_system_parameter_string)
 */
void pSeries_cmo_feature_init(void)
{
        char *ptr, *key, *value, *end;
        int call_status;
        int page_order = IOMMU_PAGE_SHIFT;

        pr_debug(" -> fw_cmo_feature_init()\n");
        spin_lock(&rtas_data_buf_lock);
        memset(rtas_data_buf, 0, RTAS_DATA_BUF_SIZE);
        call_status = rtas_call(rtas_token("ibm,get-system-parameter"), 3, 1,
                                NULL,
                                CMO_CHARACTERISTICS_TOKEN,
                                __pa(rtas_data_buf),
                                RTAS_DATA_BUF_SIZE);

        if (call_status != 0) {
                spin_unlock(&rtas_data_buf_lock);
                pr_debug("CMO not available\n");
                pr_debug(" <- fw_cmo_feature_init()\n");
                return;
        }

        end = rtas_data_buf + CMO_MAXLENGTH - 2;
        ptr = rtas_data_buf + 2;        /* step over strlen value */
        key = value = ptr;

        while (*ptr && (ptr <= end)) {
                /* Separate the key and value by replacing '=' with '\0' and
                 * point the value at the string after the '='
                 */
                if (ptr[0] == '=') {
                        ptr[0] = '\0';
                        value = ptr + 1;
                } else if (ptr[0] == '\0' || ptr[0] == ',') {
                        /* Terminate the string containing the key/value pair */
                        ptr[0] = '\0';

                        if (key == value) {
                                pr_debug("Malformed key/value pair\n");
                                /* Never found a '=', end processing */
                                break;
                        }

                        if (0 == strcmp(key, "CMOPageSize"))
                                page_order = simple_strtol(value, NULL, 10);
                        else if (0 == strcmp(key, "PrPSP"))
                                CMO_PrPSP = simple_strtol(value, NULL, 10);
                        else if (0 == strcmp(key, "SecPSP"))
                                CMO_SecPSP = simple_strtol(value, NULL, 10);
                        value = key = ptr + 1;
                }
                ptr++;
        }

        /* Page size is returned as the power of 2 of the page size,
         * convert to the page size in bytes before returning
         */
        CMO_PageSize = 1 << page_order;
        pr_debug("CMO_PageSize = %lu\n", CMO_PageSize);

        if (CMO_PrPSP != -1 || CMO_SecPSP != -1) {
                pr_info("CMO enabled\n");
                pr_debug("CMO enabled, PrPSP=%d, SecPSP=%d\n", CMO_PrPSP,
                         CMO_SecPSP);
                powerpc_firmware_features |= FW_FEATURE_CMO;
        } else
                pr_debug("CMO not enabled, PrPSP=%d, SecPSP=%d\n", CMO_PrPSP,
                         CMO_SecPSP);
        spin_unlock(&rtas_data_buf_lock);
        pr_debug(" <- fw_cmo_feature_init()\n");
}

/*
 * Early initialization.  Relocation is on but do not reference unbolted pages
 */
static void __init pSeries_init_early(void)
{
        pr_debug(" -> pSeries_init_early()\n");

        if (firmware_has_feature(FW_FEATURE_LPAR))
                find_udbg_vterm();

        if (firmware_has_feature(FW_FEATURE_DABR))
                ppc_md.set_dabr = pseries_set_dabr;
        else if (firmware_has_feature(FW_FEATURE_XDABR))
                ppc_md.set_dabr = pseries_set_xdabr;

        pSeries_cmo_feature_init();
        iommu_init_early_pSeries();

        pr_debug(" <- pSeries_init_early()\n");
}

/*
 * Called very early, MMU is off, device-tree isn't unflattened
 */

static int __init pSeries_probe_hypertas(unsigned long node,
                                         const char *uname, int depth,
                                         void *data)
{
        const char *hypertas;
        unsigned long len;

        if (depth != 1 ||
            (strcmp(uname, "rtas") != 0 && strcmp(uname, "rtas@0") != 0))
                return 0;

        hypertas = of_get_flat_dt_prop(node, "ibm,hypertas-functions", &len);
        if (!hypertas)
                return 1;

        powerpc_firmware_features |= FW_FEATURE_LPAR;
        fw_feature_init(hypertas, len);

        return 1;
}

static int __init pSeries_probe(void)
{
        unsigned long root = of_get_flat_dt_root();
        char *dtype = of_get_flat_dt_prop(root, "device_type", NULL);

        if (dtype == NULL)
                return 0;
        if (strcmp(dtype, "chrp"))
                return 0;

        /* Cell blades firmware claims to be chrp while it's not. Until this
         * is fixed, we need to avoid those here.
         */
        if (of_flat_dt_is_compatible(root, "IBM,CPBW-1.0") ||
            of_flat_dt_is_compatible(root, "IBM,CBEA"))
                return 0;

        pr_debug("pSeries detected, looking for LPAR capability...\n");

        /* Now try to figure out if we are running on LPAR */
        of_scan_flat_dt(pSeries_probe_hypertas, NULL);

        if (firmware_has_feature(FW_FEATURE_LPAR))
                hpte_init_lpar();
        else
                hpte_init_native();

        pr_debug("Machine is%s LPAR !\n",
                 (powerpc_firmware_features & FW_FEATURE_LPAR) ? "" : " not");

        return 1;
}


DECLARE_PER_CPU(long, smt_snooze_delay);

static void pseries_dedicated_idle_sleep(void)
{ 
        unsigned int cpu = smp_processor_id();
        unsigned long start_snooze;
        unsigned long in_purr, out_purr;
        long snooze = __get_cpu_var(smt_snooze_delay);

        /*
         * Indicate to the HV that we are idle. Now would be
         * a good time to find other work to dispatch.
         */
        get_lppaca()->idle = 1;
        get_lppaca()->donate_dedicated_cpu = 1;
        in_purr = mfspr(SPRN_PURR);

        /*
         * We come in with interrupts disabled, and need_resched()
         * has been checked recently.  If we should poll for a little
         * while, do so.
         */
        if (snooze) {
                start_snooze = get_tb() + snooze * tb_ticks_per_usec;
                local_irq_enable();
                set_thread_flag(TIF_POLLING_NRFLAG);

                while ((snooze < 0) || (get_tb() < start_snooze)) {
                        if (need_resched() || cpu_is_offline(cpu))
                                goto out;
                        ppc64_runlatch_off();
                        HMT_low();
                        HMT_very_low();
                }

                HMT_medium();
                clear_thread_flag(TIF_POLLING_NRFLAG);
                smp_mb();
                local_irq_disable();
                if (need_resched() || cpu_is_offline(cpu))
                        goto out;
        }

        cede_processor();

out:
        HMT_medium();
        out_purr = mfspr(SPRN_PURR);
        get_lppaca()->wait_state_cycles += out_purr - in_purr;
        get_lppaca()->donate_dedicated_cpu = 0;
        get_lppaca()->idle = 0;
}

static void pseries_shared_idle_sleep(void)
{
        /*
         * Indicate to the HV that we are idle. Now would be
         * a good time to find other work to dispatch.
         */
        get_lppaca()->idle = 1;

        /*
         * Yield the processor to the hypervisor.  We return if
         * an external interrupt occurs (which are driven prior
         * to returning here) or if a prod occurs from another
         * processor. When returning here, external interrupts
         * are enabled.
         */
        cede_processor();

        get_lppaca()->idle = 0;
}

static int pSeries_pci_probe_mode(struct pci_bus *bus)
{
        if (firmware_has_feature(FW_FEATURE_LPAR))
                return PCI_PROBE_DEVTREE;
        return PCI_PROBE_NORMAL;
}

/**
 * pSeries_power_off - tell firmware about how to power off the system.
 *
 * This function calls either the power-off rtas token in normal cases
 * or the ibm,power-off-ups token (if present & requested) in case of
 * a power failure. If power-off token is used, power on will only be
 * possible with power button press. If ibm,power-off-ups token is used
 * it will allow auto poweron after power is restored.
 */
static void pSeries_power_off(void)
{
        int rc;
        int rtas_poweroff_ups_token = rtas_token("ibm,power-off-ups");

        if (rtas_flash_term_hook)
                rtas_flash_term_hook(SYS_POWER_OFF);

        if (rtas_poweron_auto == 0 ||
                rtas_poweroff_ups_token == RTAS_UNKNOWN_SERVICE) {
                rc = rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1);
                printk(KERN_INFO "RTAS power-off returned %d\n", rc);
        } else {
                rc = rtas_call(rtas_poweroff_ups_token, 0, 1, NULL);
                printk(KERN_INFO "RTAS ibm,power-off-ups returned %d\n", rc);
        }
        for (;;);
}

#ifndef CONFIG_PCI
void pSeries_final_fixup(void) { }
#endif

define_machine(pseries) {
        .name                   = "pSeries",
        .probe                  = pSeries_probe,
        .setup_arch             = pSeries_setup_arch,
        .init_early             = pSeries_init_early,
        .show_cpuinfo           = pSeries_show_cpuinfo,
        .log_error              = pSeries_log_error,
        .pcibios_fixup          = pSeries_final_fixup,
        .pci_probe_mode         = pSeries_pci_probe_mode,
        .restart                = rtas_restart,
        .power_off              = pSeries_power_off,
        .halt                   = rtas_halt,
        .panic                  = rtas_os_term,
        .get_boot_time          = rtas_get_boot_time,
        .get_rtc_time           = rtas_get_rtc_time,
        .set_rtc_time           = rtas_set_rtc_time,
        .calibrate_decr         = generic_calibrate_decr,
        .progress               = rtas_progress,
        .system_reset_exception = pSeries_system_reset_exception,
        .machine_check_exception = pSeries_machine_check_exception,
};