/*
 * IBM Summit-Specific Code
 *
 * Written By: Matthew Dobson, IBM Corporation
 *
 * Copyright (c) 2003 IBM Corp.
 *
 * All rights reserved.
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 * NON INFRINGEMENT.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * Send feedback to <colpatch@us.ibm.com>
 *
 */

#define pr_fmt(fmt) "summit: %s: " fmt, __func__

#include <linux/mm.h>
#include <linux/init.h>
#include <asm/io.h>
#include <asm/bios_ebda.h>

/*
 * APIC driver for the IBM "Summit" chipset.
 */
#include <linux/threads.h>
#include <linux/cpumask.h>
#include <asm/mpspec.h>
#include <asm/apic.h>
#include <asm/smp.h>
#include <asm/fixmap.h>
#include <asm/apicdef.h>
#include <asm/ipi.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/gfp.h>
#include <linux/smp.h>

static unsigned summit_get_apic_id(unsigned long x)
{
        return (x >> 24) & 0xFF;
}

static inline void summit_send_IPI_mask(const struct cpumask *mask, int vector)
{
        default_send_IPI_mask_sequence_logical(mask, vector);
}

static void summit_send_IPI_allbutself(int vector)
{
        default_send_IPI_mask_allbutself_logical(cpu_online_mask, vector);
}

static void summit_send_IPI_all(int vector)
{
        summit_send_IPI_mask(cpu_online_mask, vector);
}

#include <asm/tsc.h>

extern int use_cyclone;

#ifdef CONFIG_X86_SUMMIT_NUMA
static void setup_summit(void);
#else
static inline void setup_summit(void) {}
#endif

static int summit_mps_oem_check(struct mpc_table *mpc, char *oem,
                char *productid)
{
        if (!strncmp(oem, "IBM ENSW", 8) &&
                        (!strncmp(productid, "VIGIL SMP", 9)
                         || !strncmp(productid, "EXA", 3)
                         || !strncmp(productid, "RUTHLESS SMP", 12))){
                mark_tsc_unstable("Summit based system");
                use_cyclone = 1; /*enable cyclone-timer*/
                setup_summit();
                return 1;
        }
        return 0;
}

/* Hook from generic ACPI tables.c */
static int summit_acpi_madt_oem_check(char *oem_id, char *oem_table_id)
{
        if (!strncmp(oem_id, "IBM", 3) &&
            (!strncmp(oem_table_id, "SERVIGIL", 8)
             || !strncmp(oem_table_id, "EXA", 3))){
                mark_tsc_unstable("Summit based system");
                use_cyclone = 1; /*enable cyclone-timer*/
                setup_summit();
                return 1;
        }
        return 0;
}

struct rio_table_hdr {
        unsigned char version;      /* Version number of this data structure           */
                                    /* Version 3 adds chassis_num & WP_index           */
        unsigned char num_scal_dev; /* # of Scalability devices (Twisters for Vigil)   */
        unsigned char num_rio_dev;  /* # of RIO I/O devices (Cyclones and Winnipegs)   */
} __attribute__((packed));

struct scal_detail {
        unsigned char node_id;      /* Scalability Node ID                             */
        unsigned long CBAR;         /* Address of 1MB register space                   */
        unsigned char port0node;    /* Node ID port connected to: 0xFF=None            */
        unsigned char port0port;    /* Port num port connected to: 0,1,2, or 0xFF=None */
        unsigned char port1node;    /* Node ID port connected to: 0xFF = None          */
        unsigned char port1port;    /* Port num port connected to: 0,1,2, or 0xFF=None */
        unsigned char port2node;    /* Node ID port connected to: 0xFF = None          */
        unsigned char port2port;    /* Port num port connected to: 0,1,2, or 0xFF=None */
        unsigned char chassis_num;  /* 1 based Chassis number (1 = boot node)          */
} __attribute__((packed));

struct rio_detail {
        unsigned char node_id;      /* RIO Node ID                                     */
        unsigned long BBAR;         /* Address of 1MB register space                   */
        unsigned char type;         /* Type of device                                  */
        unsigned char owner_id;     /* For WPEG: Node ID of Cyclone that owns this WPEG*/
                                    /* For CYC:  Node ID of Twister that owns this CYC */
        unsigned char port0node;    /* Node ID port connected to: 0xFF=None            */
        unsigned char port0port;    /* Port num port connected to: 0,1,2, or 0xFF=None */
        unsigned char port1node;    /* Node ID port connected to: 0xFF=None            */
        unsigned char port1port;    /* Port num port connected to: 0,1,2, or 0xFF=None */
        unsigned char first_slot;   /* For WPEG: Lowest slot number below this WPEG    */
                                    /* For CYC:  0                                     */
        unsigned char status;       /* For WPEG: Bit 0 = 1 : the XAPIC is used         */
                                    /*                 = 0 : the XAPIC is not used, ie:*/
                                    /*                     ints fwded to another XAPIC */
                                    /*           Bits1:7 Reserved                      */
                                    /* For CYC:  Bits0:7 Reserved                      */
        unsigned char WP_index;     /* For WPEG: WPEG instance index - lower ones have */
                                    /*           lower slot numbers/PCI bus numbers    */
                                    /* For CYC:  No meaning                            */
        unsigned char chassis_num;  /* 1 based Chassis number                          */
                                    /* For LookOut WPEGs this field indicates the      */
                                    /* Expansion Chassis #, enumerated from Boot       */
                                    /* Node WPEG external port, then Boot Node CYC     */
                                    /* external port, then Next Vigil chassis WPEG     */
                                    /* external port, etc.                             */
                                    /* Shared Lookouts have only 1 chassis number (the */
                                    /* first one assigned)                             */
} __attribute__((packed));


typedef enum {
        CompatTwister = 0,  /* Compatibility Twister               */
        AltTwister    = 1,  /* Alternate Twister of internal 8-way */
        CompatCyclone = 2,  /* Compatibility Cyclone               */
        AltCyclone    = 3,  /* Alternate Cyclone of internal 8-way */
        CompatWPEG    = 4,  /* Compatibility WPEG                  */
        AltWPEG       = 5,  /* Second Planar WPEG                  */
        LookOutAWPEG  = 6,  /* LookOut WPEG                        */
        LookOutBWPEG  = 7,  /* LookOut WPEG                        */
} node_type;

static inline int is_WPEG(struct rio_detail *rio){
        return (rio->type == CompatWPEG || rio->type == AltWPEG ||
                rio->type == LookOutAWPEG || rio->type == LookOutBWPEG);
}

#define SUMMIT_APIC_DFR_VALUE   (APIC_DFR_CLUSTER)

static const struct cpumask *summit_target_cpus(void)
{
        /* CPU_MASK_ALL (0xff) has undefined behaviour with
         * dest_LowestPrio mode logical clustered apic interrupt routing
         * Just start on cpu 0.  IRQ balancing will spread load
         */
        return cpumask_of(0);
}

static unsigned long summit_check_apicid_used(physid_mask_t *map, int apicid)
{
        return 0;
}

/* we don't use the phys_cpu_present_map to indicate apicid presence */
static unsigned long summit_check_apicid_present(int bit)
{
        return 1;
}

static int summit_early_logical_apicid(int cpu)
{
        int count = 0;
        u8 my_id = early_per_cpu(x86_cpu_to_apicid, cpu);
        u8 my_cluster = APIC_CLUSTER(my_id);
#ifdef CONFIG_SMP
        u8 lid;
        int i;

        /* Create logical APIC IDs by counting CPUs already in cluster. */
        for (count = 0, i = nr_cpu_ids; --i >= 0; ) {
                lid = early_per_cpu(x86_cpu_to_logical_apicid, i);
                if (lid != BAD_APICID && APIC_CLUSTER(lid) == my_cluster)
                        ++count;
        }
#endif
        /* We only have a 4 wide bitmap in cluster mode.  If a deranged
         * BIOS puts 5 CPUs in one APIC cluster, we're hosed. */
        BUG_ON(count >= XAPIC_DEST_CPUS_SHIFT);
        return my_cluster | (1UL << count);
}

static void summit_init_apic_ldr(void)
{
        int cpu = smp_processor_id();
        unsigned long id = early_per_cpu(x86_cpu_to_logical_apicid, cpu);
        unsigned long val;

        apic_write(APIC_DFR, SUMMIT_APIC_DFR_VALUE);
        val = apic_read(APIC_LDR) & ~APIC_LDR_MASK;
        val |= SET_APIC_LOGICAL_ID(id);
        apic_write(APIC_LDR, val);
}

static int summit_apic_id_registered(void)
{
        return 1;
}

static void summit_setup_apic_routing(void)
{
        pr_info("Enabling APIC mode:  Summit.  Using %d I/O APICs\n",
                nr_ioapics);
}

static int summit_cpu_present_to_apicid(int mps_cpu)
{
        if (mps_cpu < nr_cpu_ids)
                return (int)per_cpu(x86_bios_cpu_apicid, mps_cpu);
        else
                return BAD_APICID;
}

static void summit_ioapic_phys_id_map(physid_mask_t *phys_id_map, physid_mask_t *retmap)
{
        /* For clustered we don't have a good way to do this yet - hack */
        physids_promote(0x0FL, retmap);
}

static void summit_apicid_to_cpu_present(int apicid, physid_mask_t *retmap)
{
        physid_set_mask_of_physid(0, retmap);
}

static int summit_check_phys_apicid_present(int physical_apicid)
{
        return 1;
}

static inline int
summit_cpu_mask_to_apicid(const struct cpumask *cpumask, unsigned int *dest_id)
{
        unsigned int round = 0;
        unsigned int cpu, apicid = 0;

        /*
         * The cpus in the mask must all be on the apic cluster.
         */
        for_each_cpu_and(cpu, cpumask, cpu_online_mask) {
                int new_apicid = early_per_cpu(x86_cpu_to_logical_apicid, cpu);

                if (round && APIC_CLUSTER(apicid) != APIC_CLUSTER(new_apicid)) {
                        pr_err("Not a valid mask!\n");
                        return -EINVAL;
                }
                apicid |= new_apicid;
                round++;
        }
        if (!round)
                return -EINVAL;
        *dest_id = apicid;
        return 0;
}

static int
summit_cpu_mask_to_apicid_and(const struct cpumask *inmask,
                              const struct cpumask *andmask,
                              unsigned int *apicid)
{
        cpumask_var_t cpumask;
        *apicid = early_per_cpu(x86_cpu_to_logical_apicid, 0);

        if (!alloc_cpumask_var(&cpumask, GFP_ATOMIC))
                return 0;

        cpumask_and(cpumask, inmask, andmask);
        summit_cpu_mask_to_apicid(cpumask, apicid);

        free_cpumask_var(cpumask);

        return 0;
}

/*
 * cpuid returns the value latched in the HW at reset, not the APIC ID
 * register's value.  For any box whose BIOS changes APIC IDs, like
 * clustered APIC systems, we must use hard_smp_processor_id.
 *
 * See Intel's IA-32 SW Dev's Manual Vol2 under CPUID.
 */
static int summit_phys_pkg_id(int cpuid_apic, int index_msb)
{
        return hard_smp_processor_id() >> index_msb;
}

static int probe_summit(void)
{
        /* probed later in mptable/ACPI hooks */
        return 0;
}

#ifdef CONFIG_X86_SUMMIT_NUMA
static struct rio_table_hdr *rio_table_hdr;
static struct scal_detail   *scal_devs[MAX_NUMNODES];
static struct rio_detail    *rio_devs[MAX_NUMNODES*4];

#ifndef CONFIG_X86_NUMAQ
static int mp_bus_id_to_node[MAX_MP_BUSSES];
#endif

static int setup_pci_node_map_for_wpeg(int wpeg_num, int last_bus)
{
        int twister = 0, node = 0;
        int i, bus, num_buses;

        for (i = 0; i < rio_table_hdr->num_rio_dev; i++) {
                if (rio_devs[i]->node_id == rio_devs[wpeg_num]->owner_id) {
                        twister = rio_devs[i]->owner_id;
                        break;
                }
        }
        if (i == rio_table_hdr->num_rio_dev) {
                pr_err("Couldn't find owner Cyclone for Winnipeg!\n");
                return last_bus;
        }

        for (i = 0; i < rio_table_hdr->num_scal_dev; i++) {
                if (scal_devs[i]->node_id == twister) {
                        node = scal_devs[i]->node_id;
                        break;
                }
        }
        if (i == rio_table_hdr->num_scal_dev) {
                pr_err("Couldn't find owner Twister for Cyclone!\n");
                return last_bus;
        }

        switch (rio_devs[wpeg_num]->type) {
        case CompatWPEG:
                /*
                 * The Compatibility Winnipeg controls the 2 legacy buses,
                 * the 66MHz PCI bus [2 slots] and the 2 "extra" buses in case
                 * a PCI-PCI bridge card is used in either slot: total 5 buses.
                 */
                num_buses = 5;
                break;
        case AltWPEG:
                /*
                 * The Alternate Winnipeg controls the 2 133MHz buses [1 slot
                 * each], their 2 "extra" buses, the 100MHz bus [2 slots] and
                 * the "extra" buses for each of those slots: total 7 buses.
                 */
                num_buses = 7;
                break;
        case LookOutAWPEG:
        case LookOutBWPEG:
                /*
                 * A Lookout Winnipeg controls 3 100MHz buses [2 slots each]
                 * & the "extra" buses for each of those slots: total 9 buses.
                 */
                num_buses = 9;
                break;
        default:
                pr_info("Unsupported Winnipeg type!\n");
                return last_bus;
        }

        for (bus = last_bus; bus < last_bus + num_buses; bus++)
                mp_bus_id_to_node[bus] = node;
        return bus;
}

static int build_detail_arrays(void)
{
        unsigned long ptr;
        int i, scal_detail_size, rio_detail_size;

        if (rio_table_hdr->num_scal_dev > MAX_NUMNODES) {
                pr_warn("MAX_NUMNODES too low!  Defined as %d, but system has %d nodes\n",
                        MAX_NUMNODES, rio_table_hdr->num_scal_dev);
                return 0;
        }

        switch (rio_table_hdr->version) {
        default:
                pr_warn("Invalid Rio Grande Table Version: %d\n",
                        rio_table_hdr->version);
                return 0;
        case 2:
                scal_detail_size = 11;
                rio_detail_size = 13;
                break;
        case 3:
                scal_detail_size = 12;
                rio_detail_size = 15;
                break;
        }

        ptr = (unsigned long)rio_table_hdr + 3;
        for (i = 0; i < rio_table_hdr->num_scal_dev; i++, ptr += scal_detail_size)
                scal_devs[i] = (struct scal_detail *)ptr;

        for (i = 0; i < rio_table_hdr->num_rio_dev; i++, ptr += rio_detail_size)
                rio_devs[i] = (struct rio_detail *)ptr;

        return 1;
}

void setup_summit(void)
{
        unsigned long           ptr;
        unsigned short          offset;
        int                     i, next_wpeg, next_bus = 0;

        /* The pointer to the EBDA is stored in the word @ phys 0x40E(40:0E) */
        ptr = get_bios_ebda();
        ptr = (unsigned long)phys_to_virt(ptr);

        rio_table_hdr = NULL;
        offset = 0x180;
        while (offset) {
                /* The block id is stored in the 2nd word */
                if (*((unsigned short *)(ptr + offset + 2)) == 0x4752) {
                        /* set the pointer past the offset & block id */
                        rio_table_hdr = (struct rio_table_hdr *)(ptr + offset + 4);
                        break;
                }
                /* The next offset is stored in the 1st word.  0 means no more */
                offset = *((unsigned short *)(ptr + offset));
        }
        if (!rio_table_hdr) {
                pr_err("Unable to locate Rio Grande Table in EBDA - bailing!\n");
                return;
        }

        if (!build_detail_arrays())
                return;

        /* The first Winnipeg we're looking for has an index of 0 */
        next_wpeg = 0;
        do {
                for (i = 0; i < rio_table_hdr->num_rio_dev; i++) {
                        if (is_WPEG(rio_devs[i]) && rio_devs[i]->WP_index == next_wpeg) {
                                /* It's the Winnipeg we're looking for! */
                                next_bus = setup_pci_node_map_for_wpeg(i, next_bus);
                                next_wpeg++;
                                break;
                        }
                }
                /*
                 * If we go through all Rio devices and don't find one with
                 * the next index, it means we've found all the Winnipegs,
                 * and thus all the PCI buses.
                 */
                if (i == rio_table_hdr->num_rio_dev)
                        next_wpeg = 0;
        } while (next_wpeg != 0);
}
#endif

static struct apic apic_summit = {

        .name                           = "summit",
        .probe                          = probe_summit,
        .acpi_madt_oem_check            = summit_acpi_madt_oem_check,
        .apic_id_valid                  = default_apic_id_valid,
        .apic_id_registered             = summit_apic_id_registered,

        .irq_delivery_mode              = dest_LowestPrio,
        /* logical delivery broadcast to all CPUs: */
        .irq_dest_mode                  = 1,

        .target_cpus                    = summit_target_cpus,
        .disable_esr                    = 1,
        .dest_logical                   = APIC_DEST_LOGICAL,
        .check_apicid_used              = summit_check_apicid_used,
        .check_apicid_present           = summit_check_apicid_present,

        .vector_allocation_domain       = flat_vector_allocation_domain,
        .init_apic_ldr                  = summit_init_apic_ldr,

        .ioapic_phys_id_map             = summit_ioapic_phys_id_map,
        .setup_apic_routing             = summit_setup_apic_routing,
        .multi_timer_check              = NULL,
        .cpu_present_to_apicid          = summit_cpu_present_to_apicid,
        .apicid_to_cpu_present          = summit_apicid_to_cpu_present,
        .setup_portio_remap             = NULL,
        .check_phys_apicid_present      = summit_check_phys_apicid_present,
        .enable_apic_mode               = NULL,
        .phys_pkg_id                    = summit_phys_pkg_id,
        .mps_oem_check                  = summit_mps_oem_check,

        .get_apic_id                    = summit_get_apic_id,
        .set_apic_id                    = NULL,
        .apic_id_mask                   = 0xFF << 24,

        .cpu_mask_to_apicid_and         = summit_cpu_mask_to_apicid_and,

        .send_IPI_mask                  = summit_send_IPI_mask,
        .send_IPI_mask_allbutself       = NULL,
        .send_IPI_allbutself            = summit_send_IPI_allbutself,
        .send_IPI_all                   = summit_send_IPI_all,
        .send_IPI_self                  = default_send_IPI_self,

        .trampoline_phys_low            = DEFAULT_TRAMPOLINE_PHYS_LOW,
        .trampoline_phys_high           = DEFAULT_TRAMPOLINE_PHYS_HIGH,

        .wait_for_init_deassert         = default_wait_for_init_deassert,

        .smp_callin_clear_local_apic    = NULL,
        .inquire_remote_apic            = default_inquire_remote_apic,

        .read                           = native_apic_mem_read,
        .write                          = native_apic_mem_write,
        .eoi_write                      = native_apic_mem_write,
        .icr_read                       = native_apic_icr_read,
        .icr_write                      = native_apic_icr_write,
        .wait_icr_idle                  = native_apic_wait_icr_idle,
        .safe_wait_icr_idle             = native_safe_apic_wait_icr_idle,

        .x86_32_early_logical_apicid    = summit_early_logical_apicid,
};

apic_driver(apic_summit);