/*
 * linux/arch/sh/mm/init.c
 *
 *  Copyright (C) 1999  Niibe Yutaka
 *  Copyright (C) 2002 - 2007  Paul Mundt
 *
 *  Based on linux/arch/i386/mm/init.c:
 *   Copyright (C) 1995  Linus Torvalds
 */
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/init.h>
#include <linux/bootmem.h>
#include <linux/proc_fs.h>
#include <linux/pagemap.h>
#include <linux/percpu.h>
#include <linux/io.h>
#include <asm/mmu_context.h>
#include <asm/tlb.h>
#include <asm/cacheflush.h>
#include <asm/sections.h>
#include <asm/cache.h>

DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
pgd_t swapper_pg_dir[PTRS_PER_PGD];

#ifdef CONFIG_SUPERH32
/*
 * Handle trivial transitions between cached and uncached
 * segments, making use of the 1:1 mapping relationship in
 * 512MB lowmem.
 *
 * This is the offset of the uncached section from its cached alias.
 * Default value only valid in 29 bit mode, in 32bit mode will be
 * overridden in pmb_init.
 */
unsigned long cached_to_uncached = P2SEG - P1SEG;
#endif

#ifdef CONFIG_MMU
static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot)
{
        pgd_t *pgd;
        pud_t *pud;
        pmd_t *pmd;
        pte_t *pte;

        pgd = pgd_offset_k(addr);
        if (pgd_none(*pgd)) {
                pgd_ERROR(*pgd);
                return;
        }

        pud = pud_alloc(NULL, pgd, addr);
        if (unlikely(!pud)) {
                pud_ERROR(*pud);
                return;
        }

        pmd = pmd_alloc(NULL, pud, addr);
        if (unlikely(!pmd)) {
                pmd_ERROR(*pmd);
                return;
        }

        pte = pte_offset_kernel(pmd, addr);
        if (!pte_none(*pte)) {
                pte_ERROR(*pte);
                return;
        }

        set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, prot));
        local_flush_tlb_one(get_asid(), addr);
}

/*
 * As a performance optimization, other platforms preserve the fixmap mapping
 * across a context switch, we don't presently do this, but this could be done
 * in a similar fashion as to the wired TLB interface that sh64 uses (by way
 * of the memory mapped UTLB configuration) -- this unfortunately forces us to
 * give up a TLB entry for each mapping we want to preserve. While this may be
 * viable for a small number of fixmaps, it's not particularly useful for
 * everything and needs to be carefully evaluated. (ie, we may want this for
 * the vsyscall page).
 *
 * XXX: Perhaps add a _PAGE_WIRED flag or something similar that we can pass
 * in at __set_fixmap() time to determine the appropriate behavior to follow.
 *
 *                                       -- PFM.
 */
void __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot)
{
        unsigned long address = __fix_to_virt(idx);

        if (idx >= __end_of_fixed_addresses) {
                BUG();
                return;
        }

        set_pte_phys(address, phys, prot);
}

void __init page_table_range_init(unsigned long start, unsigned long end,
                                         pgd_t *pgd_base)
{
        pgd_t *pgd;
        pud_t *pud;
        pmd_t *pmd;
        pte_t *pte;
        int i, j, k;
        unsigned long vaddr;

        vaddr = start;
        i = __pgd_offset(vaddr);
        j = __pud_offset(vaddr);
        k = __pmd_offset(vaddr);
        pgd = pgd_base + i;

        for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
                pud = (pud_t *)pgd;
                for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
                        pmd = (pmd_t *)pud;
                        for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
                                if (pmd_none(*pmd)) {
                                        pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
                                        pmd_populate_kernel(&init_mm, pmd, pte);
                                        BUG_ON(pte != pte_offset_kernel(pmd, 0));
                                }
                                vaddr += PMD_SIZE;
                        }
                        k = 0;
                }
                j = 0;
        }
}
#endif  /* CONFIG_MMU */

/*
 * paging_init() sets up the page tables
 */
void __init paging_init(void)
{
        unsigned long max_zone_pfns[MAX_NR_ZONES];
        unsigned long vaddr, end;
        int nid;

        /* We don't need to map the kernel through the TLB, as
         * it is permanatly mapped using P1. So clear the
         * entire pgd. */
        memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));

        /* Set an initial value for the MMU.TTB so we don't have to
         * check for a null value. */
        set_TTB(swapper_pg_dir);

        /*
         * Populate the relevant portions of swapper_pg_dir so that
         * we can use the fixmap entries without calling kmalloc.
         * pte's will be filled in by __set_fixmap().
         */
        vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
        end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
        page_table_range_init(vaddr, end, swapper_pg_dir);

        kmap_coherent_init();

        memset(max_zone_pfns, 0, sizeof(max_zone_pfns));

        for_each_online_node(nid) {
                pg_data_t *pgdat = NODE_DATA(nid);
                unsigned long low, start_pfn;

                start_pfn = pgdat->bdata->node_min_pfn;
                low = pgdat->bdata->node_low_pfn;

                if (max_zone_pfns[ZONE_NORMAL] < low)
                        max_zone_pfns[ZONE_NORMAL] = low;

                printk("Node %u: start_pfn = 0x%lx, low = 0x%lx\n",
                       nid, start_pfn, low);
        }

        free_area_init_nodes(max_zone_pfns);

        /* Set up the uncached fixmap */
        set_fixmap_nocache(FIX_UNCACHED, __pa(&__uncached_start));
}

void __init mem_init(void)
{
        int codesize, datasize, initsize;
        int nid;

        num_physpages = 0;
        high_memory = NULL;

        for_each_online_node(nid) {
                pg_data_t *pgdat = NODE_DATA(nid);
                unsigned long node_pages = 0;
                void *node_high_memory;

                num_physpages += pgdat->node_present_pages;

                if (pgdat->node_spanned_pages)
                        node_pages = free_all_bootmem_node(pgdat);

                totalram_pages += node_pages;

                node_high_memory = (void *)__va((pgdat->node_start_pfn +
                                                 pgdat->node_spanned_pages) <<
                                                 PAGE_SHIFT);
                if (node_high_memory > high_memory)
                        high_memory = node_high_memory;
        }

        /* Set this up early, so we can take care of the zero page */
        cpu_cache_init();

        /* clear the zero-page */
        memset(empty_zero_page, 0, PAGE_SIZE);
        __flush_wback_region(empty_zero_page, PAGE_SIZE);

        codesize =  (unsigned long) &_etext - (unsigned long) &_text;
        datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
        initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;

        printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, "
               "%dk data, %dk init)\n",
                nr_free_pages() << (PAGE_SHIFT-10),
                num_physpages << (PAGE_SHIFT-10),
                codesize >> 10,
                datasize >> 10,
                initsize >> 10);

        /* Initialize the vDSO */
        vsyscall_init();
}

void free_initmem(void)
{
        unsigned long addr;

        addr = (unsigned long)(&__init_begin);
        for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
                ClearPageReserved(virt_to_page(addr));
                init_page_count(virt_to_page(addr));
                free_page(addr);
                totalram_pages++;
        }
        printk("Freeing unused kernel memory: %ldk freed\n",
               ((unsigned long)&__init_end -
                (unsigned long)&__init_begin) >> 10);
}

#ifdef CONFIG_BLK_DEV_INITRD
void free_initrd_mem(unsigned long start, unsigned long end)
{
        unsigned long p;
        for (p = start; p < end; p += PAGE_SIZE) {
                ClearPageReserved(virt_to_page(p));
                init_page_count(virt_to_page(p));
                free_page(p);
                totalram_pages++;
        }
        printk("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
}
#endif

#if THREAD_SHIFT < PAGE_SHIFT
static struct kmem_cache *thread_info_cache;

struct thread_info *alloc_thread_info(struct task_struct *tsk)
{
        struct thread_info *ti;

        ti = kmem_cache_alloc(thread_info_cache, GFP_KERNEL);
        if (unlikely(ti == NULL))
                return NULL;
#ifdef CONFIG_DEBUG_STACK_USAGE
        memset(ti, 0, THREAD_SIZE);
#endif
        return ti;
}

void free_thread_info(struct thread_info *ti)
{
        kmem_cache_free(thread_info_cache, ti);
}

void thread_info_cache_init(void)
{
        thread_info_cache = kmem_cache_create("thread_info", THREAD_SIZE,
                                              THREAD_SIZE, 0, NULL);
        BUG_ON(thread_info_cache == NULL);
}
#endif /* THREAD_SHIFT < PAGE_SHIFT */

#ifdef CONFIG_MEMORY_HOTPLUG
int arch_add_memory(int nid, u64 start, u64 size)
{
        pg_data_t *pgdat;
        unsigned long start_pfn = start >> PAGE_SHIFT;
        unsigned long nr_pages = size >> PAGE_SHIFT;
        int ret;

        pgdat = NODE_DATA(nid);

        /* We only have ZONE_NORMAL, so this is easy.. */
        ret = __add_pages(nid, pgdat->node_zones + ZONE_NORMAL,
                                start_pfn, nr_pages);
        if (unlikely(ret))
                printk("%s: Failed, __add_pages() == %d\n", __func__, ret);

        return ret;
}
EXPORT_SYMBOL_GPL(arch_add_memory);

#ifdef CONFIG_NUMA
int memory_add_physaddr_to_nid(u64 addr)
{
        /* Node 0 for now.. */
        return 0;
}
EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
#endif
#endif /* CONFIG_MEMORY_HOTPLUG */