/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2000, 05 by Ralf Baechle (ralf@linux-mips.org)
 * Copyright (C) 2000 by Silicon Graphics, Inc.
 * Copyright (C) 2004 by Christoph Hellwig
 *
 * On SGI IP27 the ARC memory configuration data is completely bogus but
 * alternate easier to use mechanisms are available.
 */
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/memblock.h>
#include <linux/mm.h>
#include <linux/mmzone.h>
#include <linux/export.h>
#include <linux/nodemask.h>
#include <linux/swap.h>
#include <linux/pfn.h>
#include <linux/highmem.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/sections.h>
#include <asm/sgialib.h>

#include <asm/sn/arch.h>
#include <asm/sn/agent.h>
#include <asm/sn/klconfig.h>

#include "ip27-common.h"

#define SLOT_PFNSHIFT           (SLOT_SHIFT - PAGE_SHIFT)
#define PFN_NASIDSHFT           (NASID_SHFT - PAGE_SHIFT)

struct node_data *__node_data[MAX_NUMNODES];
EXPORT_SYMBOL(__node_data);

static u64 gen_region_mask(void)
{
        int region_shift;
        u64 region_mask;
        nasid_t nasid;

        region_shift = get_region_shift();
        region_mask = 0;
        for_each_online_node(nasid)
                region_mask |= BIT_ULL(nasid >> region_shift);

        return region_mask;
}

#define rou_rflag       rou_flags

static int router_distance;

static void router_recurse(klrou_t *router_a, klrou_t *router_b, int depth)
{
        klrou_t *router;
        lboard_t *brd;
        int     port;

        if (router_a->rou_rflag == 1)
                return;

        if (depth >= router_distance)
                return;

        router_a->rou_rflag = 1;

        for (port = 1; port <= MAX_ROUTER_PORTS; port++) {
                if (router_a->rou_port[port].port_nasid == INVALID_NASID)
                        continue;

                brd = (lboard_t *)NODE_OFFSET_TO_K0(
                        router_a->rou_port[port].port_nasid,
                        router_a->rou_port[port].port_offset);

                if (brd->brd_type == KLTYPE_ROUTER) {
                        router = (klrou_t *)NODE_OFFSET_TO_K0(NASID_GET(brd), brd->brd_compts[0]);
                        if (router == router_b) {
                                if (depth < router_distance)
                                        router_distance = depth;
                        }
                        else
                                router_recurse(router, router_b, depth + 1);
                }
        }

        router_a->rou_rflag = 0;
}

unsigned char __node_distances[MAX_NUMNODES][MAX_NUMNODES];
EXPORT_SYMBOL(__node_distances);

static int __init compute_node_distance(nasid_t nasid_a, nasid_t nasid_b)
{
        klrou_t *router, *router_a = NULL, *router_b = NULL;
        lboard_t *brd, *dest_brd;
        nasid_t nasid;
        int port;

        /* Figure out which routers nodes in question are connected to */
        for_each_online_node(nasid) {
                brd = find_lboard_class((lboard_t *)KL_CONFIG_INFO(nasid),
                                        KLTYPE_ROUTER);

                if (!brd)
                        continue;

                do {
                        if (brd->brd_flags & DUPLICATE_BOARD)
                                continue;

                        router = (klrou_t *)NODE_OFFSET_TO_K0(NASID_GET(brd), brd->brd_compts[0]);
                        router->rou_rflag = 0;

                        for (port = 1; port <= MAX_ROUTER_PORTS; port++) {
                                if (router->rou_port[port].port_nasid == INVALID_NASID)
                                        continue;

                                dest_brd = (lboard_t *)NODE_OFFSET_TO_K0(
                                        router->rou_port[port].port_nasid,
                                        router->rou_port[port].port_offset);

                                if (dest_brd->brd_type == KLTYPE_IP27) {
                                        if (dest_brd->brd_nasid == nasid_a)
                                                router_a = router;
                                        if (dest_brd->brd_nasid == nasid_b)
                                                router_b = router;
                                }
                        }

                } while ((brd = find_lboard_class(KLCF_NEXT(brd), KLTYPE_ROUTER)));
        }

        if (nasid_a == nasid_b)
                return LOCAL_DISTANCE;

        if (router_a == router_b)
                return LOCAL_DISTANCE + 1;

        if (router_a == NULL) {
                pr_info("node_distance: router_a NULL\n");
                return 255;
        }
        if (router_b == NULL) {
                pr_info("node_distance: router_b NULL\n");
                return 255;
        }

        router_distance = 100;
        router_recurse(router_a, router_b, 2);

        return LOCAL_DISTANCE + router_distance;
}

static void __init init_topology_matrix(void)
{
        nasid_t row, col;

        for (row = 0; row < MAX_NUMNODES; row++)
                for (col = 0; col < MAX_NUMNODES; col++)
                        __node_distances[row][col] = -1;

        for_each_online_node(row) {
                for_each_online_node(col) {
                        __node_distances[row][col] =
                                compute_node_distance(row, col);
                }
        }
}

static void __init dump_topology(void)
{
        nasid_t nasid;
        lboard_t *brd, *dest_brd;
        int port;
        int router_num = 0;
        klrou_t *router;
        nasid_t row, col;

        pr_info("************** Topology ********************\n");

        pr_info("    ");
        for_each_online_node(col)
                pr_cont("%02d ", col);
        pr_cont("\n");
        for_each_online_node(row) {
                pr_info("%02d  ", row);
                for_each_online_node(col)
                        pr_cont("%2d ", node_distance(row, col));
                pr_cont("\n");
        }

        for_each_online_node(nasid) {
                brd = find_lboard_class((lboard_t *)KL_CONFIG_INFO(nasid),
                                        KLTYPE_ROUTER);

                if (!brd)
                        continue;

                do {
                        if (brd->brd_flags & DUPLICATE_BOARD)
                                continue;
                        pr_cont("Router %d:", router_num);
                        router_num++;

                        router = (klrou_t *)NODE_OFFSET_TO_K0(NASID_GET(brd), brd->brd_compts[0]);

                        for (port = 1; port <= MAX_ROUTER_PORTS; port++) {
                                if (router->rou_port[port].port_nasid == INVALID_NASID)
                                        continue;

                                dest_brd = (lboard_t *)NODE_OFFSET_TO_K0(
                                        router->rou_port[port].port_nasid,
                                        router->rou_port[port].port_offset);

                                if (dest_brd->brd_type == KLTYPE_IP27)
                                        pr_cont(" %d", dest_brd->brd_nasid);
                                if (dest_brd->brd_type == KLTYPE_ROUTER)
                                        pr_cont(" r");
                        }
                        pr_cont("\n");

                } while ( (brd = find_lboard_class(KLCF_NEXT(brd), KLTYPE_ROUTER)) );
        }
}

static unsigned long __init slot_getbasepfn(nasid_t nasid, int slot)
{
        return ((unsigned long)nasid << PFN_NASIDSHFT) | (slot << SLOT_PFNSHIFT);
}

static unsigned long __init slot_psize_compute(nasid_t nasid, int slot)
{
        lboard_t *brd;
        klmembnk_t *banks;
        unsigned long size;

        /* Find the node board */
        brd = find_lboard((lboard_t *)KL_CONFIG_INFO(nasid), KLTYPE_IP27);
        if (!brd)
                return 0;

        /* Get the memory bank structure */
        banks = (klmembnk_t *) find_first_component(brd, KLSTRUCT_MEMBNK);
        if (!banks)
                return 0;

        /* Size in _Megabytes_ */
        size = (unsigned long)banks->membnk_bnksz[slot/4];

        /* hack for 128 dimm banks */
        if (size <= 128) {
                if (slot % 4 == 0) {
                        size <<= 20;            /* size in bytes */
                        return size >> PAGE_SHIFT;
                } else
                        return 0;
        } else {
                size /= 4;
                size <<= 20;
                return size >> PAGE_SHIFT;
        }
}

static void __init mlreset(void)
{
        u64 region_mask;
        nasid_t nasid;

        master_nasid = get_nasid();

        /*
         * Probe for all CPUs - this creates the cpumask and sets up the
         * mapping tables.  We need to do this as early as possible.
         */
#ifdef CONFIG_SMP
        cpu_node_probe();
#endif

        init_topology_matrix();
        dump_topology();

        region_mask = gen_region_mask();

        setup_replication_mask();

        /*
         * Set all nodes' calias sizes to 8k
         */
        for_each_online_node(nasid) {
                /*
                 * Always have node 0 in the region mask, otherwise
                 * CALIAS accesses get exceptions since the hub
                 * thinks it is a node 0 address.
                 */
                REMOTE_HUB_S(nasid, PI_REGION_PRESENT, (region_mask | 1));
                REMOTE_HUB_S(nasid, PI_CALIAS_SIZE, PI_CALIAS_SIZE_0);

#ifdef LATER
                /*
                 * Set up all hubs to have a big window pointing at
                 * widget 0. Memory mode, widget 0, offset 0
                 */
                REMOTE_HUB_S(nasid, IIO_ITTE(SWIN0_BIGWIN),
                        ((HUB_PIO_MAP_TO_MEM << IIO_ITTE_IOSP_SHIFT) |
                        (0 << IIO_ITTE_WIDGET_SHIFT)));
#endif
        }
}

static void __init szmem(void)
{
        unsigned long slot_psize, slot0sz = 0, nodebytes;       /* Hack to detect problem configs */
        int slot;
        nasid_t node;

        for_each_online_node(node) {
                nodebytes = 0;
                for (slot = 0; slot < MAX_MEM_SLOTS; slot++) {
                        slot_psize = slot_psize_compute(node, slot);
                        if (slot == 0)
                                slot0sz = slot_psize;
                        /*
                         * We need to refine the hack when we have replicated
                         * kernel text.
                         */
                        nodebytes += (1LL << SLOT_SHIFT);

                        if (!slot_psize)
                                continue;

                        if ((nodebytes >> PAGE_SHIFT) * (sizeof(struct page)) >
                                                (slot0sz << PAGE_SHIFT)) {
                                pr_info("Ignoring slot %d onwards on node %d\n",
                                                                slot, node);
                                slot = MAX_MEM_SLOTS;
                                continue;
                        }
                        memblock_add_node(PFN_PHYS(slot_getbasepfn(node, slot)),
                                          PFN_PHYS(slot_psize), node,
                                          MEMBLOCK_NONE);
                }
        }
}

static void __init node_mem_init(nasid_t node)
{
        unsigned long slot_firstpfn = slot_getbasepfn(node, 0);
        unsigned long slot_freepfn = node_getfirstfree(node);
        unsigned long start_pfn, end_pfn;

        get_pfn_range_for_nid(node, &start_pfn, &end_pfn);

        /*
         * Allocate the node data structures on the node first.
         */
        __node_data[node] = __va(slot_freepfn << PAGE_SHIFT);
        memset(__node_data[node], 0, PAGE_SIZE);
        node_data[node] = &__node_data[node]->pglist;

        NODE_DATA(node)->node_start_pfn = start_pfn;
        NODE_DATA(node)->node_spanned_pages = end_pfn - start_pfn;

        cpumask_clear(&hub_data(node)->h_cpus);

        slot_freepfn += PFN_UP(sizeof(struct pglist_data) +
                               sizeof(struct hub_data));

        memblock_reserve(slot_firstpfn << PAGE_SHIFT,
                         ((slot_freepfn - slot_firstpfn) << PAGE_SHIFT));
}

/*
 * A node with nothing.  We use it to avoid any special casing in
 * cpumask_of_node
 */
static struct node_data null_node = {
        .hub = {
                .h_cpus = CPU_MASK_NONE
        }
};

/*
 * Currently, the intranode memory hole support assumes that each slot
 * contains at least 32 MBytes of memory. We assume all bootmem data
 * fits on the first slot.
 */
void __init prom_meminit(void)
{
        nasid_t node;

        mlreset();
        szmem();
        max_low_pfn = PHYS_PFN(memblock_end_of_DRAM());

        for (node = 0; node < MAX_NUMNODES; node++) {
                if (node_online(node)) {
                        node_mem_init(node);
                        continue;
                }
                __node_data[node] = &null_node;
        }
}

void __init arch_zone_limits_init(unsigned long *max_zone_pfns)
{
        max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
}