/*
 * Some of the code in this file has been gleaned from the 64 bit 
 * discontigmem support code base.
 *
 * Copyright (C) 2002, 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 Pat Gaughen <gone@us.ibm.com>
 */
#include <linux/mm.h>
#include <linux/bootmem.h>
#include <linux/mmzone.h>
#include <linux/acpi.h>
#include <linux/nodemask.h>
#include <asm/srat.h>
#include <asm/topology.h>
#include <asm/smp.h>
#include <asm/e820.h>

/*
 * proximity macros and definitions
 */
#define NODE_ARRAY_INDEX(x)     ((x) / 8)       /* 8 bits/char */
#define NODE_ARRAY_OFFSET(x)    ((x) % 8)       /* 8 bits/char */
#define BMAP_SET(bmap, bit)     ((bmap)[NODE_ARRAY_INDEX(bit)] |= 1 << NODE_ARRAY_OFFSET(bit))
#define BMAP_TEST(bmap, bit)    ((bmap)[NODE_ARRAY_INDEX(bit)] & (1 << NODE_ARRAY_OFFSET(bit)))
/* bitmap length; _PXM is at most 255 */
#define PXM_BITMAP_LEN (MAX_PXM_DOMAINS / 8) 
static u8 __initdata pxm_bitmap[PXM_BITMAP_LEN];        /* bitmap of proximity domains */

#define MAX_CHUNKS_PER_NODE     3
#define MAXCHUNKS               (MAX_CHUNKS_PER_NODE * MAX_NUMNODES)
struct node_memory_chunk_s {
        unsigned long   start_pfn;
        unsigned long   end_pfn;
        u8      pxm;            // proximity domain of node
        u8      nid;            // which cnode contains this chunk?
        u8      bank;           // which mem bank on this node
};
static struct node_memory_chunk_s __initdata node_memory_chunk[MAXCHUNKS];

static int __initdata num_memory_chunks; /* total number of memory chunks */
static u8 __initdata apicid_to_pxm[MAX_APICID];

int numa_off __initdata;
int acpi_numa __initdata;

static __init void bad_srat(void)
{
        printk(KERN_ERR "SRAT: SRAT not used.\n");
        acpi_numa = -1;
        num_memory_chunks = 0;
}

static __init inline int srat_disabled(void)
{
        return numa_off || acpi_numa < 0;
}

/* Identify CPU proximity domains */
void __init
acpi_numa_processor_affinity_init(struct acpi_srat_cpu_affinity *cpu_affinity)
{
        if (srat_disabled())
                return;
        if (cpu_affinity->header.length !=
             sizeof(struct acpi_srat_cpu_affinity)) {
                bad_srat();
                return;
        }

        if ((cpu_affinity->flags & ACPI_SRAT_CPU_ENABLED) == 0)
                return;         /* empty entry */

        /* mark this node as "seen" in node bitmap */
        BMAP_SET(pxm_bitmap, cpu_affinity->proximity_domain_lo);

        apicid_to_pxm[cpu_affinity->apic_id] = cpu_affinity->proximity_domain_lo;

        printk(KERN_DEBUG "CPU %02x in proximity domain %02x\n",
                cpu_affinity->apic_id, cpu_affinity->proximity_domain_lo);
}

/*
 * Identify memory proximity domains and hot-remove capabilities.
 * Fill node memory chunk list structure.
 */
void __init
acpi_numa_memory_affinity_init(struct acpi_srat_mem_affinity *memory_affinity)
{
        unsigned long long paddr, size;
        unsigned long start_pfn, end_pfn;
        u8 pxm;
        struct node_memory_chunk_s *p, *q, *pend;

        if (srat_disabled())
                return;
        if (memory_affinity->header.length !=
             sizeof(struct acpi_srat_mem_affinity)) {
                bad_srat();
                return;
        }

        if ((memory_affinity->flags & ACPI_SRAT_MEM_ENABLED) == 0)
                return;         /* empty entry */

        pxm = memory_affinity->proximity_domain & 0xff;

        /* mark this node as "seen" in node bitmap */
        BMAP_SET(pxm_bitmap, pxm);

        /* calculate info for memory chunk structure */
        paddr = memory_affinity->base_address;
        size = memory_affinity->length;

        start_pfn = paddr >> PAGE_SHIFT;
        end_pfn = (paddr + size) >> PAGE_SHIFT;


        if (num_memory_chunks >= MAXCHUNKS) {
                printk(KERN_WARNING "Too many mem chunks in SRAT."
                        " Ignoring %lld MBytes at %llx\n",
                        size/(1024*1024), paddr);
                return;
        }

        /* Insertion sort based on base address */
        pend = &node_memory_chunk[num_memory_chunks];
        for (p = &node_memory_chunk[0]; p < pend; p++) {
                if (start_pfn < p->start_pfn)
                        break;
        }
        if (p < pend) {
                for (q = pend; q >= p; q--)
                        *(q + 1) = *q;
        }
        p->start_pfn = start_pfn;
        p->end_pfn = end_pfn;
        p->pxm = pxm;

        num_memory_chunks++;

        printk(KERN_DEBUG "Memory range %08lx to %08lx"
                          " in proximity domain %02x %s\n",
                start_pfn, end_pfn,
                pxm,
                ((memory_affinity->flags & ACPI_SRAT_MEM_HOT_PLUGGABLE) ?
                 "enabled and removable" : "enabled" ) );
}

/* Callback for SLIT parsing */
void __init acpi_numa_slit_init(struct acpi_table_slit *slit)
{
}

void acpi_numa_arch_fixup(void)
{
}
/*
 * The SRAT table always lists ascending addresses, so can always
 * assume that the first "start" address that you see is the real
 * start of the node, and that the current "end" address is after
 * the previous one.
 */
static __init int node_read_chunk(int nid, struct node_memory_chunk_s *memory_chunk)
{
        /*
         * Only add present memory as told by the e820.
         * There is no guarantee from the SRAT that the memory it
         * enumerates is present at boot time because it represents
         * *possible* memory hotplug areas the same as normal RAM.
         */
        if (memory_chunk->start_pfn >= max_pfn) {
                printk(KERN_INFO "Ignoring SRAT pfns: %08lx - %08lx\n",
                        memory_chunk->start_pfn, memory_chunk->end_pfn);
                return -1;
        }
        if (memory_chunk->nid != nid)
                return -1;

        if (!node_has_online_mem(nid))
                node_start_pfn[nid] = memory_chunk->start_pfn;

        if (node_start_pfn[nid] > memory_chunk->start_pfn)
                node_start_pfn[nid] = memory_chunk->start_pfn;

        if (node_end_pfn[nid] < memory_chunk->end_pfn)
                node_end_pfn[nid] = memory_chunk->end_pfn;

        return 0;
}

int __init get_memcfg_from_srat(void)
{
        int i, j, nid;


        if (srat_disabled())
                goto out_fail;

        if (num_memory_chunks == 0) {
                printk(KERN_DEBUG
                         "could not find any ACPI SRAT memory areas.\n");
                goto out_fail;
        }

        /* Calculate total number of nodes in system from PXM bitmap and create
         * a set of sequential node IDs starting at zero.  (ACPI doesn't seem
         * to specify the range of _PXM values.)
         */
        /*
         * MCD - we no longer HAVE to number nodes sequentially.  PXM domain
         * numbers could go as high as 256, and MAX_NUMNODES for i386 is typically
         * 32, so we will continue numbering them in this manner until MAX_NUMNODES
         * approaches MAX_PXM_DOMAINS for i386.
         */
        nodes_clear(node_online_map);
        for (i = 0; i < MAX_PXM_DOMAINS; i++) {
                if (BMAP_TEST(pxm_bitmap, i)) {
                        int nid = acpi_map_pxm_to_node(i);
                        node_set_online(nid);
                }
        }
        BUG_ON(num_online_nodes() == 0);

        /* set cnode id in memory chunk structure */
        for (i = 0; i < num_memory_chunks; i++)
                node_memory_chunk[i].nid = pxm_to_node(node_memory_chunk[i].pxm);

        printk(KERN_DEBUG "pxm bitmap: ");
        for (i = 0; i < sizeof(pxm_bitmap); i++) {
                printk(KERN_CONT "%02x ", pxm_bitmap[i]);
        }
        printk(KERN_CONT "\n");
        printk(KERN_DEBUG "Number of logical nodes in system = %d\n",
                         num_online_nodes());
        printk(KERN_DEBUG "Number of memory chunks in system = %d\n",
                         num_memory_chunks);

        for (i = 0; i < MAX_APICID; i++)
                apicid_2_node[i] = pxm_to_node(apicid_to_pxm[i]);

        for (j = 0; j < num_memory_chunks; j++){
                struct node_memory_chunk_s * chunk = &node_memory_chunk[j];
                printk(KERN_DEBUG
                        "chunk %d nid %d start_pfn %08lx end_pfn %08lx\n",
                       j, chunk->nid, chunk->start_pfn, chunk->end_pfn);
                if (node_read_chunk(chunk->nid, chunk))
                        continue;

                e820_register_active_regions(chunk->nid, chunk->start_pfn,
                                             min(chunk->end_pfn, max_pfn));
        }

        for_each_online_node(nid) {
                unsigned long start = node_start_pfn[nid];
                unsigned long end = min(node_end_pfn[nid], max_pfn);

                memory_present(nid, start, end);
                node_remap_size[nid] = node_memmap_size_bytes(nid, start, end);
        }
        return 1;
out_fail:
        printk(KERN_DEBUG "failed to get NUMA memory information from SRAT"
                        " table\n");
        return 0;
}