/*
 * 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/efi.h>
#include <linux/memblock.h>
#include <linux/mm.h>
#include <linux/nmi.h>
#include <linux/swap.h>
#include <linux/sizes.h>

#include <asm/efi.h>
#include <asm/meminit.h>
#include <asm/sections.h>
#include <asm/mca.h>

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

#ifdef CONFIG_SMP
static void *cpu_data;
/**
 * per_cpu_init - setup per-cpu variables
 *
 * Allocate and setup per-cpu data areas.
 */
void *per_cpu_init(void)
{
        static bool first_time = true;
        void *cpu0_data = __cpu0_per_cpu;
        unsigned int cpu;

        if (!first_time)
                goto skip;
        first_time = false;

        /*
         * get_free_pages() cannot be used before cpu_init() done.
         * BSP allocates PERCPU_PAGE_SIZE bytes for all possible CPUs
         * to avoid that AP calls get_zeroed_page().
         */
        for_each_possible_cpu(cpu) {
                void *src = cpu == 0 ? cpu0_data : __phys_per_cpu_start;

                memcpy(cpu_data, src, __per_cpu_end - __per_cpu_start);
                __per_cpu_offset[cpu] = (char *)cpu_data - __per_cpu_start;
                per_cpu(local_per_cpu_offset, cpu) = __per_cpu_offset[cpu];

                /*
                 * percpu area for cpu0 is moved from the __init area
                 * which is setup by head.S and used till this point.
                 * Update ar.k3.  This move is ensures that percpu
                 * area for cpu0 is on the correct node and its
                 * virtual address isn't insanely far from other
                 * percpu areas which is important for congruent
                 * percpu allocator.
                 */
                if (cpu == 0)
                        ia64_set_kr(IA64_KR_PER_CPU_DATA, __pa(cpu_data) -
                                    (unsigned long)__per_cpu_start);

                cpu_data += PERCPU_PAGE_SIZE;
        }
skip:
        return __per_cpu_start + __per_cpu_offset[smp_processor_id()];
}

static inline void
alloc_per_cpu_data(void)
{
        size_t size = PERCPU_PAGE_SIZE * num_possible_cpus();

        cpu_data = memblock_alloc_from(size, PERCPU_PAGE_SIZE,
                                       __pa(MAX_DMA_ADDRESS));
        if (!cpu_data)
                panic("%s: Failed to allocate %lu bytes align=%lx from=%lx\n",
                      __func__, size, PERCPU_PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
}

/**
 * setup_per_cpu_areas - setup percpu areas
 *
 * Arch code has already allocated and initialized percpu areas.  All
 * this function has to do is to teach the determined layout to the
 * dynamic percpu allocator, which happens to be more complex than
 * creating whole new ones using helpers.
 */
void __init
setup_per_cpu_areas(void)
{
        struct pcpu_alloc_info *ai;
        struct pcpu_group_info *gi;
        unsigned int cpu;
        ssize_t static_size, reserved_size, dyn_size;

        ai = pcpu_alloc_alloc_info(1, num_possible_cpus());
        if (!ai)
                panic("failed to allocate pcpu_alloc_info");
        gi = &ai->groups[0];

        /* units are assigned consecutively to possible cpus */
        for_each_possible_cpu(cpu)
                gi->cpu_map[gi->nr_units++] = cpu;

        /* set parameters */
        static_size = __per_cpu_end - __per_cpu_start;
        reserved_size = PERCPU_MODULE_RESERVE;
        dyn_size = PERCPU_PAGE_SIZE - static_size - reserved_size;
        if (dyn_size < 0)
                panic("percpu area overflow static=%zd reserved=%zd\n",
                      static_size, reserved_size);

        ai->static_size         = static_size;
        ai->reserved_size       = reserved_size;
        ai->dyn_size            = dyn_size;
        ai->unit_size           = PERCPU_PAGE_SIZE;
        ai->atom_size           = PAGE_SIZE;
        ai->alloc_size          = PERCPU_PAGE_SIZE;

        pcpu_setup_first_chunk(ai, __per_cpu_start + __per_cpu_offset[0]);
        pcpu_free_alloc_info(ai);
}
#else
#define alloc_per_cpu_data() do { } while (0)
#endif /* CONFIG_SMP */

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

        /* first find highest page frame number */
        min_low_pfn = ~0UL;
        max_low_pfn = 0;
        efi_memmap_walk(find_max_min_low_pfn, NULL);
        max_pfn = max_low_pfn;

        memblock_add_node(0, PFN_PHYS(max_low_pfn), 0);

        find_initrd();

        alloc_per_cpu_data();
}

static int __init find_largest_hole(u64 start, u64 end, void *arg)
{
        u64 *max_gap = arg;

        static u64 last_end = PAGE_OFFSET;

        /* NOTE: this algorithm assumes efi memmap table is ordered */

        if (*max_gap < (start - last_end))
                *max_gap = start - last_end;
        last_end = end;
        return 0;
}

static void __init verify_gap_absence(void)
{
        unsigned long max_gap;

        /* Forbid FLATMEM if hole is > than 1G */
        efi_memmap_walk(find_largest_hole, (u64 *)&max_gap);
        if (max_gap >= SZ_1G)
                panic("Cannot use FLATMEM with %ldMB hole\n"
                      "Please switch over to SPARSEMEM\n",
                      (max_gap >> 20));
}

/*
 * Set up the page tables.
 */

void __init
paging_init (void)
{
        unsigned long max_dma;
        unsigned long max_zone_pfns[MAX_NR_ZONES];

        memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
        max_dma = virt_to_phys((void *) MAX_DMA_ADDRESS) >> PAGE_SHIFT;
        max_zone_pfns[ZONE_DMA32] = max_dma;
        max_zone_pfns[ZONE_NORMAL] = max_low_pfn;

        verify_gap_absence();

        free_area_init(max_zone_pfns);
        zero_page_memmap_ptr = virt_to_page(ia64_imva(empty_zero_page));
}