/*
 * 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) 1998-2003 Hewlett-Packard Co
 *      David Mosberger-Tang <davidm@hpl.hp.com>
 *      Stephane Eranian <eranian@hpl.hp.com>
 * Copyright (C) 2000, Rohit Seth <rohit.seth@intel.com>
 * Copyright (C) 1999 VA Linux Systems
 * Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
 * Copyright (C) 2003 Silicon Graphics, Inc. All rights reserved.
 *
 * Routines used by ia64 machines with contiguous (or virtually contiguous)
 * memory.
 */
#include <linux/config.h>
#include <linux/bootmem.h>
#include <linux/efi.h>
#include <linux/mm.h>
#include <linux/swap.h>

#include <asm/meminit.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/sections.h>
#include <asm/mca.h>

#ifdef CONFIG_VIRTUAL_MEM_MAP
static unsigned long num_dma_physpages;
#endif

/**
 * show_mem - display a memory statistics summary
 *
 * Just walks the pages in the system and describes where they're allocated.
 */
void
show_mem (void)
{
        int i, total = 0, reserved = 0;
        int shared = 0, cached = 0;

        printk("Mem-info:\n");
        show_free_areas();

        printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
        i = max_mapnr;
        while (i-- > 0) {
                if (!pfn_valid(i))
                        continue;
                total++;
                if (PageReserved(mem_map+i))
                        reserved++;
                else if (PageSwapCache(mem_map+i))
                        cached++;
                else if (page_count(mem_map + i))
                        shared += page_count(mem_map + i) - 1;
        }
        printk("%d pages of RAM\n", total);
        printk("%d reserved pages\n", reserved);
        printk("%d pages shared\n", shared);
        printk("%d pages swap cached\n", cached);
        printk("%ld pages in page table cache\n", pgtable_cache_size);
}

/* physical address where the bootmem map is located */
unsigned long bootmap_start;

/**
 * find_max_pfn - adjust the maximum page number callback
 * @start: start of range
 * @end: end of range
 * @arg: address of pointer to global max_pfn variable
 *
 * Passed as a callback function to efi_memmap_walk() to determine the highest
 * available page frame number in the system.
 */
int
find_max_pfn (unsigned long start, unsigned long end, void *arg)
{
        unsigned long *max_pfnp = arg, pfn;

        pfn = (PAGE_ALIGN(end - 1) - PAGE_OFFSET) >> PAGE_SHIFT;
        if (pfn > *max_pfnp)
                *max_pfnp = pfn;
        return 0;
}

/**
 * find_bootmap_location - callback to find a memory area for the bootmap
 * @start: start of region
 * @end: end of region
 * @arg: unused callback data
 *
 * Find a place to put the bootmap and return its starting address in
 * bootmap_start.  This address must be page-aligned.
 */
int
find_bootmap_location (unsigned long start, unsigned long end, void *arg)
{
        unsigned long needed = *(unsigned long *)arg;
        unsigned long range_start, range_end, free_start;
        int i;

#if IGNORE_PFN0
        if (start == PAGE_OFFSET) {
                start += PAGE_SIZE;
                if (start >= end)
                        return 0;
        }
#endif

        free_start = PAGE_OFFSET;

        for (i = 0; i < num_rsvd_regions; i++) {
                range_start = max(start, free_start);
                range_end   = min(end, rsvd_region[i].start & PAGE_MASK);

                free_start = PAGE_ALIGN(rsvd_region[i].end);

                if (range_end <= range_start)
                        continue; /* skip over empty range */

                if (range_end - range_start >= needed) {
                        bootmap_start = __pa(range_start);
                        return -1;      /* done */
                }

                /* nothing more available in this segment */
                if (range_end == end)
                        return 0;
        }
        return 0;
}

/**
 * find_memory - setup memory map
 *
 * Walk the EFI memory map and find usable memory for the system, taking
 * into account reserved areas.
 */
void
find_memory (void)
{
        unsigned long bootmap_size;

        reserve_memory();

        /* first find highest page frame number */
        max_pfn = 0;
        efi_memmap_walk(find_max_pfn, &max_pfn);

        /* how many bytes to cover all the pages */
        bootmap_size = bootmem_bootmap_pages(max_pfn) << PAGE_SHIFT;

        /* look for a location to hold the bootmap */
        bootmap_start = ~0UL;
        efi_memmap_walk(find_bootmap_location, &bootmap_size);
        if (bootmap_start == ~0UL)
                panic("Cannot find %ld bytes for bootmap\n", bootmap_size);

        bootmap_size = init_bootmem(bootmap_start >> PAGE_SHIFT, max_pfn);

        /* Free all available memory, then mark bootmem-map as being in use. */
        efi_memmap_walk(filter_rsvd_memory, free_bootmem);
        reserve_bootmem(bootmap_start, bootmap_size);

        find_initrd();
}

#ifdef CONFIG_SMP
/**
 * per_cpu_init - setup per-cpu variables
 *
 * Allocate and setup per-cpu data areas.
 */
void *
per_cpu_init (void)
{
        void *cpu_data;
        int cpu;

        /*
         * get_free_pages() cannot be used before cpu_init() done.  BSP
         * allocates "NR_CPUS" pages for all CPUs to avoid that AP calls
         * get_zeroed_page().
         */
        if (smp_processor_id() == 0) {
                cpu_data = __alloc_bootmem(PERCPU_PAGE_SIZE * NR_CPUS,
                                           PERCPU_PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
                for (cpu = 0; cpu < NR_CPUS; cpu++) {
                        memcpy(cpu_data, __phys_per_cpu_start, __per_cpu_end - __per_cpu_start);
                        __per_cpu_offset[cpu] = (char *) cpu_data - __per_cpu_start;
                        cpu_data += PERCPU_PAGE_SIZE;
                        per_cpu(local_per_cpu_offset, cpu) = __per_cpu_offset[cpu];
                }
        }
        return __per_cpu_start + __per_cpu_offset[smp_processor_id()];
}
#endif /* CONFIG_SMP */

static int
count_pages (u64 start, u64 end, void *arg)
{
        unsigned long *count = arg;

        *count += (end - start) >> PAGE_SHIFT;
        return 0;
}

#ifdef CONFIG_VIRTUAL_MEM_MAP
static int
count_dma_pages (u64 start, u64 end, void *arg)
{
        unsigned long *count = arg;

        if (start < MAX_DMA_ADDRESS)
                *count += (min(end, MAX_DMA_ADDRESS) - start) >> PAGE_SHIFT;
        return 0;
}
#endif

/*
 * Set up the page tables.
 */

void
paging_init (void)
{
        unsigned long max_dma;
        unsigned long zones_size[MAX_NR_ZONES];
#ifdef CONFIG_VIRTUAL_MEM_MAP
        unsigned long zholes_size[MAX_NR_ZONES];
        unsigned long max_gap;
#endif

        /* initialize mem_map[] */

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

        num_physpages = 0;
        efi_memmap_walk(count_pages, &num_physpages);

        max_dma = virt_to_phys((void *) MAX_DMA_ADDRESS) >> PAGE_SHIFT;

#ifdef CONFIG_VIRTUAL_MEM_MAP
        memset(zholes_size, 0, sizeof(zholes_size));

        num_dma_physpages = 0;
        efi_memmap_walk(count_dma_pages, &num_dma_physpages);

        if (max_low_pfn < max_dma) {
                zones_size[ZONE_DMA] = max_low_pfn;
                zholes_size[ZONE_DMA] = max_low_pfn - num_dma_physpages;
        } else {
                zones_size[ZONE_DMA] = max_dma;
                zholes_size[ZONE_DMA] = max_dma - num_dma_physpages;
                if (num_physpages > num_dma_physpages) {
                        zones_size[ZONE_NORMAL] = max_low_pfn - max_dma;
                        zholes_size[ZONE_NORMAL] =
                                ((max_low_pfn - max_dma) -
                                 (num_physpages - num_dma_physpages));
                }
        }

        max_gap = 0;
        efi_memmap_walk(find_largest_hole, (u64 *)&max_gap);
        if (max_gap < LARGE_GAP) {
                vmem_map = (struct page *) 0;
                free_area_init_node(0, &contig_page_data, zones_size, 0,
                                    zholes_size);
        } else {
                unsigned long map_size;

                /* allocate virtual_mem_map */

                map_size = PAGE_ALIGN(max_low_pfn * sizeof(struct page));
                vmalloc_end -= map_size;
                vmem_map = (struct page *) vmalloc_end;
                efi_memmap_walk(create_mem_map_page_table, NULL);

                mem_map = contig_page_data.node_mem_map = vmem_map;
                free_area_init_node(0, &contig_page_data, zones_size,
                                    0, zholes_size);

                printk("Virtual mem_map starts at 0x%p\n", mem_map);
        }
#else /* !CONFIG_VIRTUAL_MEM_MAP */
        if (max_low_pfn < max_dma)
                zones_size[ZONE_DMA] = max_low_pfn;
        else {
                zones_size[ZONE_DMA] = max_dma;
                zones_size[ZONE_NORMAL] = max_low_pfn - max_dma;
        }
        free_area_init(zones_size);
#endif /* !CONFIG_VIRTUAL_MEM_MAP */
        zero_page_memmap_ptr = virt_to_page(ia64_imva(empty_zero_page));
}