/*
 *  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/export.h>
#include <linux/delay.h>
#include <linux/irq.h>
#include <linux/seq_file.h>
#include <linux/root_dev.h>
#include <linux/of.h>
#include <linux/of_pci.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 <asm/pmc.h>
#include <asm/xics.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/reg.h>
#include <asm/plpar_wrappers.h>
#include <asm/kexec.h>

#include "pseries.h"

int CMO_PrPSP = -1;
int CMO_SecPSP = -1;
unsigned long CMO_PageSize = (ASM_CONST(1) << IOMMU_PAGE_SHIFT_4K);
EXPORT_SYMBOL(CMO_PageSize);

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

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(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_init_irq(void)
{
        xics_init();
        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 int pci_dn_reconfig_notifier(struct notifier_block *nb, unsigned long action, void *data)
{
        struct of_reconfig_data *rd = data;
        struct device_node *parent, *np = rd->dn;
        struct pci_dn *pdn;
        int err = NOTIFY_OK;

        switch (action) {
        case OF_RECONFIG_ATTACH_NODE:
                parent = of_get_parent(np);
                pdn = parent ? PCI_DN(parent) : NULL;
                if (pdn)
                        pci_add_device_node_info(pdn->phb, np);

                of_node_put(parent);
                break;
        case OF_RECONFIG_DETACH_NODE:
                pdn = PCI_DN(np);
                if (pdn)
                        list_del(&pdn->list);
                break;
        default:
                err = NOTIFY_DONE;
                break;
        }
        return err;
}

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

struct kmem_cache *dtl_cache;

#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
/*
 * 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;

        if (!firmware_has_feature(FW_FEATURE_SPLPAR))
                return 0;

        if (!dtl_cache)
                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 = cpu_to_be32(DISPATCH_LOG_BYTES);
        ret = register_dtl(hard_smp_processor_id(), __pa(dtl));
        if (ret)
                pr_err("WARNING: DTL registration of cpu %d (hw %d) failed "
                       "with %d\n", smp_processor_id(),
                       hard_smp_processor_id(), ret);
        get_paca()->lppaca_ptr->dtl_enable_mask = 2;

        return 0;
}
#else /* !CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
static inline int alloc_dispatch_logs(void)
{
        return 0;
}
#endif /* CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */

static int alloc_dispatch_log_kmem_cache(void)
{
        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;
        }

        return alloc_dispatch_logs();
}
machine_early_initcall(pseries, alloc_dispatch_log_kmem_cache);

static void pseries_lpar_idle(void)
{
        /*
         * Default handler to go into low thread priority and possibly
         * low power mode by ceding processor to hypervisor
         */

        /* Indicate to hypervisor that we are idle. */
        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;
}

/*
 * Enable relocation on during exceptions. This has partition wide scope and
 * may take a while to complete, if it takes longer than one second we will
 * just give up rather than wasting any more time on this - if that turns out
 * to ever be a problem in practice we can move this into a kernel thread to
 * finish off the process later in boot.
 */
void pseries_enable_reloc_on_exc(void)
{
        long rc;
        unsigned int delay, total_delay = 0;

        while (1) {
                rc = enable_reloc_on_exceptions();
                if (!H_IS_LONG_BUSY(rc)) {
                        if (rc == H_P2) {
                                pr_info("Relocation on exceptions not"
                                        " supported\n");
                        } else if (rc != H_SUCCESS) {
                                pr_warn("Unable to enable relocation"
                                        " on exceptions: %ld\n", rc);
                        }
                        break;
                }

                delay = get_longbusy_msecs(rc);
                total_delay += delay;
                if (total_delay > 1000) {
                        pr_warn("Warning: Giving up waiting to enable "
                                "relocation on exceptions (%u msec)!\n",
                                total_delay);
                        return;
                }

                mdelay(delay);
        }
}
EXPORT_SYMBOL(pseries_enable_reloc_on_exc);

void pseries_disable_reloc_on_exc(void)
{
        long rc;

        while (1) {
                rc = disable_reloc_on_exceptions();
                if (!H_IS_LONG_BUSY(rc))
                        break;
                mdelay(get_longbusy_msecs(rc));
        }
        if (rc != H_SUCCESS)
                pr_warning("Warning: Failed to disable relocation on "
                           "exceptions: %ld\n", rc);
}
EXPORT_SYMBOL(pseries_disable_reloc_on_exc);

#ifdef CONFIG_KEXEC
static void pSeries_machine_kexec(struct kimage *image)
{
        if (firmware_has_feature(FW_FEATURE_SET_MODE))
                pseries_disable_reloc_on_exc();

        default_machine_kexec(image);
}
#endif

#ifdef __LITTLE_ENDIAN__
void pseries_big_endian_exceptions(void)
{
        long rc;

        while (1) {
                rc = enable_big_endian_exceptions();
                if (!H_IS_LONG_BUSY(rc))
                        break;
                mdelay(get_longbusy_msecs(rc));
        }

        /*
         * At this point it is unlikely panic() will get anything
         * out to the user, since this is called very late in kexec
         * but at least this will stop us from continuing on further
         * and creating an even more difficult to debug situation.
         *
         * There is a known problem when kdump'ing, if cpus are offline
         * the above call will fail. Rather than panicking again, keep
         * going and hope the kdump kernel is also little endian, which
         * it usually is.
         */
        if (rc && !kdump_in_progress())
                panic("Could not enable big endian exceptions");
}

void pseries_little_endian_exceptions(void)
{
        long rc;

        while (1) {
                rc = enable_little_endian_exceptions();
                if (!H_IS_LONG_BUSY(rc))
                        break;
                mdelay(get_longbusy_msecs(rc));
        }
        if (rc) {
                ppc_md.progress("H_SET_MODE LE exception fail", 0);
                panic("Could not enable little endian exceptions");
        }
}
#endif

static void __init find_and_init_phbs(void)
{
        struct device_node *node;
        struct pci_controller *phb;
        struct device_node *root = of_find_node_by_path("/");

        for_each_child_of_node(root, node) {
                if (node->type == NULL || (strcmp(node->type, "pci") != 0 &&
                                           strcmp(node->type, "pciex") != 0))
                        continue;

                phb = pcibios_alloc_controller(node);
                if (!phb)
                        continue;
                rtas_setup_phb(phb);
                pci_process_bridge_OF_ranges(phb, node, 0);
                isa_bridge_find_early(phb);
                phb->controller_ops = pseries_pci_controller_ops;
        }

        of_node_put(root);

        /*
         * PCI_PROBE_ONLY and PCI_REASSIGN_ALL_BUS can be set via properties
         * in chosen.
         */
        of_pci_check_probe_only();
}

static void __init pSeries_setup_arch(void)
{
        set_arch_panic_timeout(10, ARCH_PANIC_TIMEOUT);

        /* Discover PIC type and setup ppc_md accordingly */
        smp_init_pseries();


        /* 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();

        /* By default, only probe PCI (can be overridden by rtas_pci) */
        pci_add_flags(PCI_PROBE_ONLY);

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

        pSeries_nvram_init();

        if (firmware_has_feature(FW_FEATURE_LPAR)) {
                vpa_init(boot_cpuid);
                ppc_md.power_save = pseries_lpar_idle;
                ppc_md.enable_pmcs = pseries_lpar_enable_pmcs;
        } else {
                /* No special idle routine */
                ppc_md.enable_pmcs = power4_enable_pmcs;
        }

        ppc_md.pcibios_root_bridge_prepare = pseries_root_bridge_prepare;
}

static int __init pSeries_init_panel(void)
{
        /* Manually leave the kernel version on the panel. */
#ifdef __BIG_ENDIAN__
        ppc_md.progress("Linux ppc64\n", 0);
#else
        ppc_md.progress("Linux ppc64le\n", 0);
#endif
        ppc_md.progress(init_utsname()->version, 0);

        return 0;
}
machine_arch_initcall(pseries, pSeries_init_panel);

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

static int pseries_set_xdabr(unsigned long dabr, unsigned long dabrx)
{
        /* Have to set at least one bit in the DABRX according to PAPR */
        if (dabrx == 0 && dabr == 0)
                dabrx = DABRX_USER;
        /* PAPR says we can only set kernel and user bits */
        dabrx &= DABRX_KERNEL | DABRX_USER;

        return plpar_hcall_norets(H_SET_XDABR, dabr, dabrx);
}

static int pseries_set_dawr(unsigned long dawr, unsigned long dawrx)
{
        /* PAPR says we can't set HYP */
        dawrx &= ~DAWRX_HYP;

        return  plapr_set_watchpoint0(dawr, dawrx);
}

#define CMO_CHARACTERISTICS_TOKEN 44
#define CMO_MAXLENGTH 1026

void pSeries_coalesce_init(void)
{
        struct hvcall_mpp_x_data mpp_x_data;

        if (firmware_has_feature(FW_FEATURE_CMO) && !h_get_mpp_x(&mpp_x_data))
                powerpc_firmware_features |= FW_FEATURE_XCMO;
        else
                powerpc_firmware_features &= ~FW_FEATURE_XCMO;
}

/**
 * fw_cmo_feature_init - FW_FEATURE_CMO is not stored in ibm,hypertas-functions,
 * handle that here. (Stolen from parse_system_parameter_string)
 */
static void pSeries_cmo_feature_init(void)
{
        char *ptr, *key, *value, *end;
        int call_status;
        int page_order = IOMMU_PAGE_SHIFT_4K;

        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;
                pSeries_coalesce_init();
        } 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(void)
{
        pr_debug(" -> pseries_init()\n");

#ifdef CONFIG_HVC_CONSOLE
        if (firmware_has_feature(FW_FEATURE_LPAR))
                hvc_vio_init_early();
#endif
        if (firmware_has_feature(FW_FEATURE_XDABR))
                ppc_md.set_dabr = pseries_set_xdabr;
        else if (firmware_has_feature(FW_FEATURE_DABR))
                ppc_md.set_dabr = pseries_set_dabr;

        if (firmware_has_feature(FW_FEATURE_SET_MODE))
                ppc_md.set_dawr = pseries_set_dawr;

        pSeries_cmo_feature_init();
        iommu_init_early_pSeries();

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

/**
 * 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 (;;);
}

static int __init pSeries_probe(void)
{
        const char *dtype = of_get_property(of_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_machine_is_compatible("IBM,CPBW-1.0") ||
            of_machine_is_compatible("IBM,CBEA"))
                return 0;

        pm_power_off = pseries_power_off;

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

        pseries_init();

        return 1;
}

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;
}

struct pci_controller_ops pseries_pci_controller_ops = {
        .probe_mode             = pSeries_pci_probe_mode,
};

define_machine(pseries) {
        .name                   = "pSeries",
        .probe                  = pSeries_probe,
        .setup_arch             = pSeries_setup_arch,
        .init_IRQ               = pseries_init_irq,
        .show_cpuinfo           = pSeries_show_cpuinfo,
        .log_error              = pSeries_log_error,
        .pcibios_fixup          = pSeries_final_fixup,
        .restart                = rtas_restart,
        .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,
#ifdef CONFIG_KEXEC
        .machine_kexec          = pSeries_machine_kexec,
        .kexec_cpu_down         = pseries_kexec_cpu_down,
#endif
#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
        .memory_block_size      = pseries_memory_block_size,
#endif
};