/*
 * 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/config.h>
#include <linux/mm.h>
#include <linux/bootmem.h>
#include <linux/mmzone.h>
#include <linux/acpi.h>
#include <linux/nodemask.h>
#include <asm/srat.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)))
#define MAX_PXM_DOMAINS         256     /* 1 byte and no promises about values */
/* bitmap length; _PXM is at most 255 */
#define PXM_BITMAP_LEN (MAX_PXM_DOMAINS / 8) 
static u8 pxm_bitmap[PXM_BITMAP_LEN];   /* bitmap of proximity domains */

#define MAX_CHUNKS_PER_NODE     4
#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 node_memory_chunk[MAXCHUNKS];

static int num_memory_chunks;           /* total number of memory chunks */
static int zholes_size_init;
static unsigned long zholes_size[MAX_NUMNODES * MAX_NR_ZONES];

extern unsigned long node_start_pfn[], node_end_pfn[];

extern void * boot_ioremap(unsigned long, unsigned long);

/* Identify CPU proximity domains */
static void __init parse_cpu_affinity_structure(char *p)
{
        struct acpi_table_processor_affinity *cpu_affinity = 
                                (struct acpi_table_processor_affinity *) p;

        if (!cpu_affinity->flags.enabled)
                return;         /* empty entry */

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

        printk("CPU 0x%02X in proximity domain 0x%02X\n",
                cpu_affinity->apic_id, cpu_affinity->proximity_domain);
}

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

        if (!memory_affinity->flags.enabled)
                return;         /* empty entry */

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

        /* calculate info for memory chunk structure */
        paddr = memory_affinity->base_addr_hi;
        paddr = (paddr << 32) | memory_affinity->base_addr_lo;
        size = memory_affinity->length_hi;
        size = (size << 32) | memory_affinity->length_lo;
        
        start_pfn = paddr >> PAGE_SHIFT;
        end_pfn = (paddr + size) >> PAGE_SHIFT;
        
        pxm = memory_affinity->proximity_domain;

        if (num_memory_chunks >= MAXCHUNKS) {
                printk("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("Memory range 0x%lX to 0x%lX (type 0x%X) in proximity domain 0x%02X %s\n",
                start_pfn, end_pfn,
                memory_affinity->memory_type,
                memory_affinity->proximity_domain,
                (memory_affinity->flags.hot_pluggable ?
                 "enabled and removable" : "enabled" ) );
}

#if MAX_NR_ZONES != 3
#error "MAX_NR_ZONES != 3, chunk_to_zone requires review"
#endif
/* Take a chunk of pages from page frame cstart to cend and count the number
 * of pages in each zone, returned via zones[].
 */
static __init void chunk_to_zones(unsigned long cstart, unsigned long cend, 
                unsigned long *zones)
{
        unsigned long max_dma;
        extern unsigned long max_low_pfn;

        int z;
        unsigned long rend;

        /* FIXME: MAX_DMA_ADDRESS and max_low_pfn are trying to provide
         * similarly scoped information and should be handled in a consistant
         * manner.
         */
        max_dma = virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;

        /* Split the hole into the zones in which it falls.  Repeatedly
         * take the segment in which the remaining hole starts, round it
         * to the end of that zone.
         */
        memset(zones, 0, MAX_NR_ZONES * sizeof(long));
        while (cstart < cend) {
                if (cstart < max_dma) {
                        z = ZONE_DMA;
                        rend = (cend < max_dma)? cend : max_dma;

                } else if (cstart < max_low_pfn) {
                        z = ZONE_NORMAL;
                        rend = (cend < max_low_pfn)? cend : max_low_pfn;

                } else {
                        z = ZONE_HIGHMEM;
                        rend = cend;
                }
                zones[z] += rend - cstart;
                cstart = rend;
        }
}

/* Parse the ACPI Static Resource Affinity Table */
static int __init acpi20_parse_srat(struct acpi_table_srat *sratp)
{
        u8 *start, *end, *p;
        int i, j, nid;
        u8 pxm_to_nid_map[MAX_PXM_DOMAINS];/* _PXM to logical node ID map */
        u8 nid_to_pxm_map[MAX_NUMNODES];/* logical node ID to _PXM map */

        start = (u8 *)(&(sratp->reserved) + 1); /* skip header */
        p = start;
        end = (u8 *)sratp + sratp->header.length;

        memset(pxm_bitmap, 0, sizeof(pxm_bitmap));      /* init proximity domain bitmap */
        memset(node_memory_chunk, 0, sizeof(node_memory_chunk));
        memset(zholes_size, 0, sizeof(zholes_size));

        /* -1 in these maps means not available */
        memset(pxm_to_nid_map, -1, sizeof(pxm_to_nid_map));
        memset(nid_to_pxm_map, -1, sizeof(nid_to_pxm_map));

        num_memory_chunks = 0;
        while (p < end) {
                switch (*p) {
                case ACPI_SRAT_PROCESSOR_AFFINITY:
                        parse_cpu_affinity_structure(p);
                        break;
                case ACPI_SRAT_MEMORY_AFFINITY:
                        parse_memory_affinity_structure(p);
                        break;
                default:
                        printk("ACPI 2.0 SRAT: unknown entry skipped: type=0x%02X, len=%d\n", p[0], p[1]);
                        break;
                }
                p += p[1];
                if (p[1] == 0) {
                        printk("acpi20_parse_srat: Entry length value is zero;"
                                " can't parse any further!\n");
                        break;
                }
        }

        if (num_memory_chunks == 0) {
                printk("could not finy 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)) {
                        nid = num_online_nodes();
                        pxm_to_nid_map[i] = nid;
                        nid_to_pxm_map[nid] = 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_nid_map[node_memory_chunk[i].pxm];

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

        for (j = 0; j < num_memory_chunks; j++){
                printk("chunk %d nid %d start_pfn %08lx end_pfn %08lx\n",
                       j, node_memory_chunk[j].nid,
                       node_memory_chunk[j].start_pfn,
                       node_memory_chunk[j].end_pfn);
        }
 
        /*calculate node_start_pfn/node_end_pfn arrays*/
        for_each_online_node(nid) {
                int been_here_before = 0;

                for (j = 0; j < num_memory_chunks; j++){
                        if (node_memory_chunk[j].nid == nid) {
                                if (been_here_before == 0) {
                                        node_start_pfn[nid] = node_memory_chunk[j].start_pfn;
                                        node_end_pfn[nid] = node_memory_chunk[j].end_pfn;
                                        been_here_before = 1;
                                } else { /* We've found another chunk of memory for the node */
                                        if (node_start_pfn[nid] < node_memory_chunk[j].start_pfn) {
                                                node_end_pfn[nid] = node_memory_chunk[j].end_pfn;
                                        }
                                }
                        }
                }
        }
        return 1;
out_fail:
        return 0;
}

int __init get_memcfg_from_srat(void)
{
        struct acpi_table_header *header = NULL;
        struct acpi_table_rsdp *rsdp = NULL;
        struct acpi_table_rsdt *rsdt = NULL;
        struct acpi_pointer *rsdp_address = NULL;
        struct acpi_table_rsdt saved_rsdt;
        int tables = 0;
        int i = 0;

        acpi_find_root_pointer(ACPI_PHYSICAL_ADDRESSING, rsdp_address);

        if (rsdp_address->pointer_type == ACPI_PHYSICAL_POINTER) {
                printk("%s: assigning address to rsdp\n", __FUNCTION__);
                rsdp = (struct acpi_table_rsdp *)
                                (u32)rsdp_address->pointer.physical;
        } else {
                printk("%s: rsdp_address is not a physical pointer\n", __FUNCTION__);
                goto out_err;
        }
        if (!rsdp) {
                printk("%s: Didn't find ACPI root!\n", __FUNCTION__);
                goto out_err;
        }

        printk(KERN_INFO "%.8s v%d [%.6s]\n", rsdp->signature, rsdp->revision,
                rsdp->oem_id);

        if (strncmp(rsdp->signature, RSDP_SIG,strlen(RSDP_SIG))) {
                printk(KERN_WARNING "%s: RSDP table signature incorrect\n", __FUNCTION__);
                goto out_err;
        }

        rsdt = (struct acpi_table_rsdt *)
            boot_ioremap(rsdp->rsdt_address, sizeof(struct acpi_table_rsdt));

        if (!rsdt) {
                printk(KERN_WARNING
                       "%s: ACPI: Invalid root system description tables (RSDT)\n",
                       __FUNCTION__);
                goto out_err;
        }

        header = & rsdt->header;

        if (strncmp(header->signature, RSDT_SIG, strlen(RSDT_SIG))) {
                printk(KERN_WARNING "ACPI: RSDT signature incorrect\n");
                goto out_err;
        }

        /* 
         * The number of tables is computed by taking the 
         * size of all entries (header size minus total 
         * size of RSDT) divided by the size of each entry
         * (4-byte table pointers).
         */
        tables = (header->length - sizeof(struct acpi_table_header)) / 4;

        if (!tables)
                goto out_err;

        memcpy(&saved_rsdt, rsdt, sizeof(saved_rsdt));

        if (saved_rsdt.header.length > sizeof(saved_rsdt)) {
                printk(KERN_WARNING "ACPI: Too big length in RSDT: %d\n",
                       saved_rsdt.header.length);
                goto out_err;
        }

        printk("Begin SRAT table scan....\n");

        for (i = 0; i < tables; i++) {
                /* Map in header, then map in full table length. */
                header = (struct acpi_table_header *)
                        boot_ioremap(saved_rsdt.entry[i], sizeof(struct acpi_table_header));
                if (!header)
                        break;
                header = (struct acpi_table_header *)
                        boot_ioremap(saved_rsdt.entry[i], header->length);
                if (!header)
                        break;

                if (strncmp((char *) &header->signature, "SRAT", 4))
                        continue;

                /* we've found the srat table. don't need to look at any more tables */
                return acpi20_parse_srat((struct acpi_table_srat *)header);
        }
out_err:
        printk("failed to get NUMA memory information from SRAT table\n");
        return 0;
}

/* For each node run the memory list to determine whether there are
 * any memory holes.  For each hole determine which ZONE they fall
 * into.
 *
 * NOTE#1: this requires knowledge of the zone boundries and so
 * _cannot_ be performed before those are calculated in setup_memory.
 * 
 * NOTE#2: we rely on the fact that the memory chunks are ordered by
 * start pfn number during setup.
 */
static void __init get_zholes_init(void)
{
        int nid;
        int c;
        int first;
        unsigned long end = 0;

        for_each_online_node(nid) {
                first = 1;
                for (c = 0; c < num_memory_chunks; c++){
                        if (node_memory_chunk[c].nid == nid) {
                                if (first) {
                                        end = node_memory_chunk[c].end_pfn;
                                        first = 0;

                                } else {
                                        /* Record any gap between this chunk
                                         * and the previous chunk on this node
                                         * against the zones it spans.
                                         */
                                        chunk_to_zones(end,
                                                node_memory_chunk[c].start_pfn,
                                                &zholes_size[nid * MAX_NR_ZONES]);
                                }
                        }
                }
        }
}

unsigned long * __init get_zholes_size(int nid)
{
        if (!zholes_size_init) {
                zholes_size_init++;
                get_zholes_init();
        }
        if (nid >= MAX_NUMNODES || !node_online(nid))
                printk("%s: nid = %d is invalid/offline. num_online_nodes = %d",
                       __FUNCTION__, nid, num_online_nodes());
        return &zholes_size[nid * MAX_NR_ZONES];
}