/*
 * pSeries NUMA support
 *
 * Copyright (C) 2002 Anton Blanchard <anton@au.ibm.com>, IBM
 *
 * 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.
 */
#include <linux/threads.h>
#include <linux/bootmem.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/mmzone.h>
#include <linux/module.h>
#include <linux/nodemask.h>
#include <linux/cpu.h>
#include <linux/notifier.h>
#include <asm/lmb.h>
#include <asm/machdep.h>
#include <asm/abs_addr.h>

static int numa_enabled = 1;

static int numa_debug;
#define dbg(args...) if (numa_debug) { printk(KERN_INFO args); }

#ifdef DEBUG_NUMA
#define ARRAY_INITIALISER -1
#else
#define ARRAY_INITIALISER 0
#endif

int numa_cpu_lookup_table[NR_CPUS] = { [ 0 ... (NR_CPUS - 1)] =
        ARRAY_INITIALISER};
char *numa_memory_lookup_table;
cpumask_t numa_cpumask_lookup_table[MAX_NUMNODES];
int nr_cpus_in_node[MAX_NUMNODES] = { [0 ... (MAX_NUMNODES -1)] = 0};

struct pglist_data *node_data[MAX_NUMNODES];
bootmem_data_t __initdata plat_node_bdata[MAX_NUMNODES];
static unsigned long node0_io_hole_size;
static int min_common_depth;

/*
 * We need somewhere to store start/span for each node until we have
 * allocated the real node_data structures.
 */
static struct {
        unsigned long node_start_pfn;
        unsigned long node_spanned_pages;
} init_node_data[MAX_NUMNODES] __initdata;

EXPORT_SYMBOL(node_data);
EXPORT_SYMBOL(numa_cpu_lookup_table);
EXPORT_SYMBOL(numa_memory_lookup_table);
EXPORT_SYMBOL(numa_cpumask_lookup_table);
EXPORT_SYMBOL(nr_cpus_in_node);

static inline void map_cpu_to_node(int cpu, int node)
{
        numa_cpu_lookup_table[cpu] = node;
        if (!(cpu_isset(cpu, numa_cpumask_lookup_table[node]))) {
                cpu_set(cpu, numa_cpumask_lookup_table[node]);
                nr_cpus_in_node[node]++;
        }
}

#ifdef CONFIG_HOTPLUG_CPU
static void unmap_cpu_from_node(unsigned long cpu)
{
        int node = numa_cpu_lookup_table[cpu];

        dbg("removing cpu %lu from node %d\n", cpu, node);

        if (cpu_isset(cpu, numa_cpumask_lookup_table[node])) {
                cpu_clear(cpu, numa_cpumask_lookup_table[node]);
                nr_cpus_in_node[node]--;
        } else {
                printk(KERN_ERR "WARNING: cpu %lu not found in node %d\n",
                       cpu, node);
        }
}
#endif /* CONFIG_HOTPLUG_CPU */

static struct device_node * __devinit find_cpu_node(unsigned int cpu)
{
        unsigned int hw_cpuid = get_hard_smp_processor_id(cpu);
        struct device_node *cpu_node = NULL;
        unsigned int *interrupt_server, *reg;
        int len;

        while ((cpu_node = of_find_node_by_type(cpu_node, "cpu")) != NULL) {
                /* Try interrupt server first */
                interrupt_server = (unsigned int *)get_property(cpu_node,
                                        "ibm,ppc-interrupt-server#s", &len);

                len = len / sizeof(u32);

                if (interrupt_server && (len > 0)) {
                        while (len--) {
                                if (interrupt_server[len] == hw_cpuid)
                                        return cpu_node;
                        }
                } else {
                        reg = (unsigned int *)get_property(cpu_node,
                                                           "reg", &len);
                        if (reg && (len > 0) && (reg[0] == hw_cpuid))
                                return cpu_node;
                }
        }

        return NULL;
}

/* must hold reference to node during call */
static int *of_get_associativity(struct device_node *dev)
{
        return (unsigned int *)get_property(dev, "ibm,associativity", NULL);
}

static int of_node_numa_domain(struct device_node *device)
{
        int numa_domain;
        unsigned int *tmp;

        if (min_common_depth == -1)
                return 0;

        tmp = of_get_associativity(device);
        if (tmp && (tmp[0] >= min_common_depth)) {
                numa_domain = tmp[min_common_depth];
        } else {
                dbg("WARNING: no NUMA information for %s\n",
                    device->full_name);
                numa_domain = 0;
        }
        return numa_domain;
}

/*
 * In theory, the "ibm,associativity" property may contain multiple
 * associativity lists because a resource may be multiply connected
 * into the machine.  This resource then has different associativity
 * characteristics relative to its multiple connections.  We ignore
 * this for now.  We also assume that all cpu and memory sets have
 * their distances represented at a common level.  This won't be
 * true for heirarchical NUMA.
 *
 * In any case the ibm,associativity-reference-points should give
 * the correct depth for a normal NUMA system.
 *
 * - Dave Hansen <haveblue@us.ibm.com>
 */
static int __init find_min_common_depth(void)
{
        int depth;
        unsigned int *ref_points;
        struct device_node *rtas_root;
        unsigned int len;

        rtas_root = of_find_node_by_path("/rtas");

        if (!rtas_root)
                return -1;

        /*
         * this property is 2 32-bit integers, each representing a level of
         * depth in the associativity nodes.  The first is for an SMP
         * configuration (should be all 0's) and the second is for a normal
         * NUMA configuration.
         */
        ref_points = (unsigned int *)get_property(rtas_root,
                        "ibm,associativity-reference-points", &len);

        if ((len >= 1) && ref_points) {
                depth = ref_points[1];
        } else {
                dbg("WARNING: could not find NUMA "
                    "associativity reference point\n");
                depth = -1;
        }
        of_node_put(rtas_root);

        return depth;
}

static unsigned long read_cell_ul(struct device_node *device, unsigned int **buf)
{
        int i;
        unsigned long result = 0;

        i = prom_n_size_cells(device);
        /* bug on i>2 ?? */
        while (i--) {
                result = (result << 32) | **buf;
                (*buf)++;
        }
        return result;
}

/*
 * Figure out to which domain a cpu belongs and stick it there.
 * Return the id of the domain used.
 */
static int numa_setup_cpu(unsigned long lcpu)
{
        int numa_domain = 0;
        struct device_node *cpu = find_cpu_node(lcpu);

        if (!cpu) {
                WARN_ON(1);
                goto out;
        }

        numa_domain = of_node_numa_domain(cpu);

        if (numa_domain >= num_online_nodes()) {
                /*
                 * POWER4 LPAR uses 0xffff as invalid node,
                 * dont warn in this case.
                 */
                if (numa_domain != 0xffff)
                        printk(KERN_ERR "WARNING: cpu %ld "
                               "maps to invalid NUMA node %d\n",
                               lcpu, numa_domain);
                numa_domain = 0;
        }
out:
        node_set_online(numa_domain);

        map_cpu_to_node(lcpu, numa_domain);

        of_node_put(cpu);

        return numa_domain;
}

static int cpu_numa_callback(struct notifier_block *nfb,
                             unsigned long action,
                             void *hcpu)
{
        unsigned long lcpu = (unsigned long)hcpu;
        int ret = NOTIFY_DONE;

        switch (action) {
        case CPU_UP_PREPARE:
                if (min_common_depth == -1 || !numa_enabled)
                        map_cpu_to_node(lcpu, 0);
                else
                        numa_setup_cpu(lcpu);
                ret = NOTIFY_OK;
                break;
#ifdef CONFIG_HOTPLUG_CPU
        case CPU_DEAD:
        case CPU_UP_CANCELED:
                unmap_cpu_from_node(lcpu);
                break;
                ret = NOTIFY_OK;
#endif
        }
        return ret;
}

static int __init parse_numa_properties(void)
{
        struct device_node *cpu = NULL;
        struct device_node *memory = NULL;
        int max_domain = 0;
        long entries = lmb_end_of_DRAM() >> MEMORY_INCREMENT_SHIFT;
        unsigned long i;

        if (numa_enabled == 0) {
                printk(KERN_WARNING "NUMA disabled by user\n");
                return -1;
        }

        numa_memory_lookup_table =
                (char *)abs_to_virt(lmb_alloc(entries * sizeof(char), 1));
        memset(numa_memory_lookup_table, 0, entries * sizeof(char));

        for (i = 0; i < entries ; i++)
                numa_memory_lookup_table[i] = ARRAY_INITIALISER;

        min_common_depth = find_min_common_depth();

        dbg("NUMA associativity depth for CPU/Memory: %d\n", min_common_depth);
        if (min_common_depth < 0)
                return min_common_depth;

        max_domain = numa_setup_cpu(boot_cpuid);

        /*
         * Even though we connect cpus to numa domains later in SMP init,
         * we need to know the maximum node id now. This is because each
         * node id must have NODE_DATA etc backing it.
         * As a result of hotplug we could still have cpus appear later on
         * with larger node ids. In that case we force the cpu into node 0.
         */
        for_each_cpu(i) {
                int numa_domain;

                cpu = find_cpu_node(i);

                if (cpu) {
                        numa_domain = of_node_numa_domain(cpu);
                        of_node_put(cpu);

                        if (numa_domain < MAX_NUMNODES &&
                            max_domain < numa_domain)
                                max_domain = numa_domain;
                }
        }

        memory = NULL;
        while ((memory = of_find_node_by_type(memory, "memory")) != NULL) {
                unsigned long start;
                unsigned long size;
                int numa_domain;
                int ranges;
                unsigned int *memcell_buf;
                unsigned int len;

                memcell_buf = (unsigned int *)get_property(memory, "reg", &len);
                if (!memcell_buf || len <= 0)
                        continue;

                ranges = memory->n_addrs;
new_range:
                /* these are order-sensitive, and modify the buffer pointer */
                start = read_cell_ul(memory, &memcell_buf);
                size = read_cell_ul(memory, &memcell_buf);

                start = _ALIGN_DOWN(start, MEMORY_INCREMENT);
                size = _ALIGN_UP(size, MEMORY_INCREMENT);

                numa_domain = of_node_numa_domain(memory);

                if (numa_domain >= MAX_NUMNODES) {
                        if (numa_domain != 0xffff)
                                printk(KERN_ERR "WARNING: memory at %lx maps "
                                       "to invalid NUMA node %d\n", start,
                                       numa_domain);
                        numa_domain = 0;
                }

                if (max_domain < numa_domain)
                        max_domain = numa_domain;

                /* 
                 * For backwards compatibility, OF splits the first node
                 * into two regions (the first being 0-4GB). Check for
                 * this simple case and complain if there is a gap in
                 * memory
                 */
                if (init_node_data[numa_domain].node_spanned_pages) {
                        unsigned long shouldstart =
                                init_node_data[numa_domain].node_start_pfn +
                                init_node_data[numa_domain].node_spanned_pages;
                        if (shouldstart != (start / PAGE_SIZE)) {
                                /* Revert to non-numa for now */
                                printk(KERN_ERR
                                       "WARNING: Unexpected node layout: "
                                       "region start %lx length %lx\n",
                                       start, size);
                                printk(KERN_ERR "NUMA is disabled\n");
                                goto err;
                        }
                        init_node_data[numa_domain].node_spanned_pages +=
                                size / PAGE_SIZE;
                } else {
                        node_set_online(numa_domain);

                        init_node_data[numa_domain].node_start_pfn =
                                start / PAGE_SIZE;
                        init_node_data[numa_domain].node_spanned_pages =
                                size / PAGE_SIZE;
                }

                for (i = start ; i < (start+size); i += MEMORY_INCREMENT)
                        numa_memory_lookup_table[i >> MEMORY_INCREMENT_SHIFT] =
                                numa_domain;

                ranges--;
                if (ranges)
                        goto new_range;
        }

        for (i = 0; i <= max_domain; i++)
                node_set_online(i);

        return 0;
err:
        /* Something has gone wrong; revert any setup we've done */
        for_each_node(i) {
                node_set_offline(i);
                init_node_data[i].node_start_pfn = 0;
                init_node_data[i].node_spanned_pages = 0;
        }
        return -1;
}

static void __init setup_nonnuma(void)
{
        unsigned long top_of_ram = lmb_end_of_DRAM();
        unsigned long total_ram = lmb_phys_mem_size();
        unsigned long i;

        printk(KERN_INFO "Top of RAM: 0x%lx, Total RAM: 0x%lx\n",
               top_of_ram, total_ram);
        printk(KERN_INFO "Memory hole size: %ldMB\n",
               (top_of_ram - total_ram) >> 20);

        if (!numa_memory_lookup_table) {
                long entries = top_of_ram >> MEMORY_INCREMENT_SHIFT;
                numa_memory_lookup_table =
                        (char *)abs_to_virt(lmb_alloc(entries * sizeof(char), 1));
                memset(numa_memory_lookup_table, 0, entries * sizeof(char));
                for (i = 0; i < entries ; i++)
                        numa_memory_lookup_table[i] = ARRAY_INITIALISER;
        }

        map_cpu_to_node(boot_cpuid, 0);

        node_set_online(0);

        init_node_data[0].node_start_pfn = 0;
        init_node_data[0].node_spanned_pages = lmb_end_of_DRAM() / PAGE_SIZE;

        for (i = 0 ; i < top_of_ram; i += MEMORY_INCREMENT)
                numa_memory_lookup_table[i >> MEMORY_INCREMENT_SHIFT] = 0;

        node0_io_hole_size = top_of_ram - total_ram;
}

static void __init dump_numa_topology(void)
{
        unsigned int node;
        unsigned int count;

        if (min_common_depth == -1 || !numa_enabled)
                return;

        for_each_online_node(node) {
                unsigned long i;

                printk(KERN_INFO "Node %d Memory:", node);

                count = 0;

                for (i = 0; i < lmb_end_of_DRAM(); i += MEMORY_INCREMENT) {
                        if (numa_memory_lookup_table[i >> MEMORY_INCREMENT_SHIFT] == node) {
                                if (count == 0)
                                        printk(" 0x%lx", i);
                                ++count;
                        } else {
                                if (count > 0)
                                        printk("-0x%lx", i);
                                count = 0;
                        }
                }

                if (count > 0)
                        printk("-0x%lx", i);
                printk("\n");
        }
        return;
}

/*
 * Allocate some memory, satisfying the lmb or bootmem allocator where
 * required. nid is the preferred node and end is the physical address of
 * the highest address in the node.
 *
 * Returns the physical address of the memory.
 */
static unsigned long careful_allocation(int nid, unsigned long size,
                                        unsigned long align, unsigned long end)
{
        unsigned long ret = lmb_alloc_base(size, align, end);

        /* retry over all memory */
        if (!ret)
                ret = lmb_alloc_base(size, align, lmb_end_of_DRAM());

        if (!ret)
                panic("numa.c: cannot allocate %lu bytes on node %d",
                      size, nid);

        /*
         * If the memory came from a previously allocated node, we must
         * retry with the bootmem allocator.
         */
        if (pa_to_nid(ret) < nid) {
                nid = pa_to_nid(ret);
                ret = (unsigned long)__alloc_bootmem_node(NODE_DATA(nid),
                                size, align, 0);

                if (!ret)
                        panic("numa.c: cannot allocate %lu bytes on node %d",
                              size, nid);

                ret = virt_to_abs(ret);

                dbg("alloc_bootmem %lx %lx\n", ret, size);
        }

        return ret;
}

void __init do_init_bootmem(void)
{
        int nid;
        static struct notifier_block ppc64_numa_nb = {
                .notifier_call = cpu_numa_callback,
                .priority = 1 /* Must run before sched domains notifier. */
        };

        min_low_pfn = 0;
        max_low_pfn = lmb_end_of_DRAM() >> PAGE_SHIFT;
        max_pfn = max_low_pfn;

        if (parse_numa_properties())
                setup_nonnuma();
        else
                dump_numa_topology();

        register_cpu_notifier(&ppc64_numa_nb);

        for_each_online_node(nid) {
                unsigned long start_paddr, end_paddr;
                int i;
                unsigned long bootmem_paddr;
                unsigned long bootmap_pages;

                start_paddr = init_node_data[nid].node_start_pfn * PAGE_SIZE;
                end_paddr = start_paddr + (init_node_data[nid].node_spanned_pages * PAGE_SIZE);

                /* Allocate the node structure node local if possible */
                NODE_DATA(nid) = (struct pglist_data *)careful_allocation(nid,
                                        sizeof(struct pglist_data),
                                        SMP_CACHE_BYTES, end_paddr);
                NODE_DATA(nid) = abs_to_virt(NODE_DATA(nid));
                memset(NODE_DATA(nid), 0, sizeof(struct pglist_data));

                dbg("node %d\n", nid);
                dbg("NODE_DATA() = %p\n", NODE_DATA(nid));

                NODE_DATA(nid)->bdata = &plat_node_bdata[nid];
                NODE_DATA(nid)->node_start_pfn =
                        init_node_data[nid].node_start_pfn;
                NODE_DATA(nid)->node_spanned_pages =
                        init_node_data[nid].node_spanned_pages;

                if (init_node_data[nid].node_spanned_pages == 0)
                        continue;

                dbg("start_paddr = %lx\n", start_paddr);
                dbg("end_paddr = %lx\n", end_paddr);

                bootmap_pages = bootmem_bootmap_pages((end_paddr - start_paddr) >> PAGE_SHIFT);

                bootmem_paddr = careful_allocation(nid,
                                bootmap_pages << PAGE_SHIFT,
                                PAGE_SIZE, end_paddr);
                memset(abs_to_virt(bootmem_paddr), 0,
                       bootmap_pages << PAGE_SHIFT);
                dbg("bootmap_paddr = %lx\n", bootmem_paddr);

                init_bootmem_node(NODE_DATA(nid), bootmem_paddr >> PAGE_SHIFT,
                                  start_paddr >> PAGE_SHIFT,
                                  end_paddr >> PAGE_SHIFT);

                for (i = 0; i < lmb.memory.cnt; i++) {
                        unsigned long physbase, size;

                        physbase = lmb.memory.region[i].physbase;
                        size = lmb.memory.region[i].size;

                        if (physbase < end_paddr &&
                            (physbase+size) > start_paddr) {
                                /* overlaps */
                                if (physbase < start_paddr) {
                                        size -= start_paddr - physbase;
                                        physbase = start_paddr;
                                }

                                if (size > end_paddr - physbase)
                                        size = end_paddr - physbase;

                                dbg("free_bootmem %lx %lx\n", physbase, size);
                                free_bootmem_node(NODE_DATA(nid), physbase,
                                                  size);
                        }
                }

                for (i = 0; i < lmb.reserved.cnt; i++) {
                        unsigned long physbase = lmb.reserved.region[i].physbase;
                        unsigned long size = lmb.reserved.region[i].size;

                        if (physbase < end_paddr &&
                            (physbase+size) > start_paddr) {
                                /* overlaps */
                                if (physbase < start_paddr) {
                                        size -= start_paddr - physbase;
                                        physbase = start_paddr;
                                }

                                if (size > end_paddr - physbase)
                                        size = end_paddr - physbase;

                                dbg("reserve_bootmem %lx %lx\n", physbase,
                                    size);
                                reserve_bootmem_node(NODE_DATA(nid), physbase,
                                                     size);
                        }
                }
        }
}

void __init paging_init(void)
{
        unsigned long zones_size[MAX_NR_ZONES];
        unsigned long zholes_size[MAX_NR_ZONES];
        int nid;

        memset(zones_size, 0, sizeof(zones_size));
        memset(zholes_size, 0, sizeof(zholes_size));

        for_each_online_node(nid) {
                unsigned long start_pfn;
                unsigned long end_pfn;

                start_pfn = plat_node_bdata[nid].node_boot_start >> PAGE_SHIFT;
                end_pfn = plat_node_bdata[nid].node_low_pfn;

                zones_size[ZONE_DMA] = end_pfn - start_pfn;
                zholes_size[ZONE_DMA] = 0;
                if (nid == 0)
                        zholes_size[ZONE_DMA] = node0_io_hole_size >> PAGE_SHIFT;

                dbg("free_area_init node %d %lx %lx (hole: %lx)\n", nid,
                    zones_size[ZONE_DMA], start_pfn, zholes_size[ZONE_DMA]);

                free_area_init_node(nid, NODE_DATA(nid), zones_size,
                                                        start_pfn, zholes_size);
        }
}

static int __init early_numa(char *p)
{
        if (!p)
                return 0;

        if (strstr(p, "off"))
                numa_enabled = 0;

        if (strstr(p, "debug"))
                numa_debug = 1;

        return 0;
}
early_param("numa", early_numa);