memory-hotplug: introduce new arch_remove_memory() for removing page table

[mirror_ubuntu-bionic-kernel.git] / arch / sh / mm / init.c

/*
 * linux/arch/sh/mm/init.c
 *
 *  Copyright (C) 1999  Niibe Yutaka
 *  Copyright (C) 2002 - 2011  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/gfp.h>
#include <linux/bootmem.h>
#include <linux/proc_fs.h>
#include <linux/pagemap.h>
#include <linux/percpu.h>
#include <linux/io.h>
#include <linux/memblock.h>
#include <linux/dma-mapping.h>
#include <linux/export.h>
#include <asm/mmu_context.h>
#include <asm/mmzone.h>
#include <asm/kexec.h>
#include <asm/tlb.h>
#include <asm/cacheflush.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/cache.h>
#include <asm/sizes.h>

pgd_t swapper_pg_dir[PTRS_PER_PGD];

void __init generic_mem_init(void)
{
        memblock_add(__MEMORY_START, __MEMORY_SIZE);
}

void __init __weak plat_mem_setup(void)
{
        /* Nothing to see here, move along. */
}

#ifdef CONFIG_MMU
static pte_t *__get_pte_phys(unsigned long addr)
{
        pgd_t *pgd;
        pud_t *pud;
        pmd_t *pmd;

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

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

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

        return pte_offset_kernel(pmd, addr);
}

static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot)
{
        pte_t *pte;

        pte = __get_pte_phys(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);

        if (pgprot_val(prot) & _PAGE_WIRED)
                tlb_wire_entry(NULL, addr, *pte);
}

static void clear_pte_phys(unsigned long addr, pgprot_t prot)
{
        pte_t *pte;

        pte = __get_pte_phys(addr);

        if (pgprot_val(prot) & _PAGE_WIRED)
                tlb_unwire_entry();

        set_pte(pte, pfn_pte(0, __pgprot(0)));
        local_flush_tlb_one(get_asid(), addr);
}

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 __clear_fixmap(enum fixed_addresses idx, pgprot_t prot)
{
        unsigned long address = __fix_to_virt(idx);

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

        clear_pte_phys(address, prot);
}

static pmd_t * __init one_md_table_init(pud_t *pud)
{
        if (pud_none(*pud)) {
                pmd_t *pmd;

                pmd = alloc_bootmem_pages(PAGE_SIZE);
                pud_populate(&init_mm, pud, pmd);
                BUG_ON(pmd != pmd_offset(pud, 0));
        }

        return pmd_offset(pud, 0);
}

static pte_t * __init one_page_table_init(pmd_t *pmd)
{
        if (pmd_none(*pmd)) {
                pte_t *pte;

                pte = alloc_bootmem_pages(PAGE_SIZE);
                pmd_populate_kernel(&init_mm, pmd, pte);
                BUG_ON(pte != pte_offset_kernel(pmd, 0));
        }

        return pte_offset_kernel(pmd, 0);
}

static pte_t * __init page_table_kmap_check(pte_t *pte, pmd_t *pmd,
                                            unsigned long vaddr, pte_t *lastpte)
{
        return pte;
}

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 = NULL;
        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 = one_md_table_init(pud);
#ifndef __PAGETABLE_PMD_FOLDED
                        pmd += k;
#endif
                        for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
                                pte = page_table_kmap_check(one_page_table_init(pmd),
                                                            pmd, vaddr, pte);
                                vaddr += PMD_SIZE;
                        }
                        k = 0;
                }
                j = 0;
        }
}
#endif  /* CONFIG_MMU */

void __init allocate_pgdat(unsigned int nid)
{
        unsigned long start_pfn, end_pfn;
#ifdef CONFIG_NEED_MULTIPLE_NODES
        unsigned long phys;
#endif

        get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);

#ifdef CONFIG_NEED_MULTIPLE_NODES
        phys = __memblock_alloc_base(sizeof(struct pglist_data),
                                SMP_CACHE_BYTES, end_pfn << PAGE_SHIFT);
        /* Retry with all of system memory */
        if (!phys)
                phys = __memblock_alloc_base(sizeof(struct pglist_data),
                                        SMP_CACHE_BYTES, memblock_end_of_DRAM());
        if (!phys)
                panic("Can't allocate pgdat for node %d\n", nid);

        NODE_DATA(nid) = __va(phys);
        memset(NODE_DATA(nid), 0, sizeof(struct pglist_data));

        NODE_DATA(nid)->bdata = &bootmem_node_data[nid];
#endif

        NODE_DATA(nid)->node_start_pfn = start_pfn;
        NODE_DATA(nid)->node_spanned_pages = end_pfn - start_pfn;
}

static void __init bootmem_init_one_node(unsigned int nid)
{
        unsigned long total_pages, paddr;
        unsigned long end_pfn;
        struct pglist_data *p;

        p = NODE_DATA(nid);

        /* Nothing to do.. */
        if (!p->node_spanned_pages)
                return;

        end_pfn = p->node_start_pfn + p->node_spanned_pages;

        total_pages = bootmem_bootmap_pages(p->node_spanned_pages);

        paddr = memblock_alloc(total_pages << PAGE_SHIFT, PAGE_SIZE);
        if (!paddr)
                panic("Can't allocate bootmap for nid[%d]\n", nid);

        init_bootmem_node(p, paddr >> PAGE_SHIFT, p->node_start_pfn, end_pfn);

        free_bootmem_with_active_regions(nid, end_pfn);

        /*
         * XXX Handle initial reservations for the system memory node
         * only for the moment, we'll refactor this later for handling
         * reservations in other nodes.
         */
        if (nid == 0) {
                struct memblock_region *reg;

                /* Reserve the sections we're already using. */
                for_each_memblock(reserved, reg) {
                        reserve_bootmem(reg->base, reg->size, BOOTMEM_DEFAULT);
                }
        }

        sparse_memory_present_with_active_regions(nid);
}

static void __init do_init_bootmem(void)
{
        struct memblock_region *reg;
        int i;

        /* Add active regions with valid PFNs. */
        for_each_memblock(memory, reg) {
                unsigned long start_pfn, end_pfn;
                start_pfn = memblock_region_memory_base_pfn(reg);
                end_pfn = memblock_region_memory_end_pfn(reg);
                __add_active_range(0, start_pfn, end_pfn);
        }

        /* All of system RAM sits in node 0 for the non-NUMA case */
        allocate_pgdat(0);
        node_set_online(0);

        plat_mem_setup();

        for_each_online_node(i)
                bootmem_init_one_node(i);

        sparse_init();
}

static void __init early_reserve_mem(void)
{
        unsigned long start_pfn;
        u32 zero_base = (u32)__MEMORY_START + (u32)PHYSICAL_OFFSET;
        u32 start = zero_base + (u32)CONFIG_ZERO_PAGE_OFFSET;

        /*
         * Partially used pages are not usable - thus
         * we are rounding upwards:
         */
        start_pfn = PFN_UP(__pa(_end));

        /*
         * Reserve the kernel text and Reserve the bootmem bitmap. We do
         * this in two steps (first step was init_bootmem()), because
         * this catches the (definitely buggy) case of us accidentally
         * initializing the bootmem allocator with an invalid RAM area.
         */
        memblock_reserve(start, (PFN_PHYS(start_pfn) + PAGE_SIZE - 1) - start);

        /*
         * Reserve physical pages below CONFIG_ZERO_PAGE_OFFSET.
         */
        if (CONFIG_ZERO_PAGE_OFFSET != 0)
                memblock_reserve(zero_base, CONFIG_ZERO_PAGE_OFFSET);

        /*
         * Handle additional early reservations
         */
        check_for_initrd();
        reserve_crashkernel();
}

void __init paging_init(void)
{
        unsigned long max_zone_pfns[MAX_NR_ZONES];
        unsigned long vaddr, end;
        int nid;

        sh_mv.mv_mem_init();

        early_reserve_mem();

        /*
         * Once the early reservations are out of the way, give the
         * platforms a chance to kick out some memory.
         */
        if (sh_mv.mv_mem_reserve)
                sh_mv.mv_mem_reserve();

        memblock_enforce_memory_limit(memory_limit);
        memblock_allow_resize();

        memblock_dump_all();

        /*
         * Determine low and high memory ranges:
         */
        max_low_pfn = max_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
        min_low_pfn = __MEMORY_START >> PAGE_SHIFT;

        nodes_clear(node_online_map);

        memory_start = (unsigned long)__va(__MEMORY_START);
        memory_end = memory_start + (memory_limit ?: memblock_phys_mem_size());

        uncached_init();
        pmb_init();
        do_init_bootmem();
        ioremap_fixed_init();

        /* 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);
}

/*
 * Early initialization for any I/O MMUs we might have.
 */
static void __init iommu_init(void)
{
        no_iommu_init();
}

unsigned int mem_init_done = 0;

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

        iommu_init();

        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);

        vsyscall_init();

        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);

        printk(KERN_INFO "virtual kernel memory layout:\n"
                "    fixmap  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
#ifdef CONFIG_HIGHMEM
                "    pkmap   : 0x%08lx - 0x%08lx   (%4ld kB)\n"
#endif
                "    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"
                "    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB) (cached)\n"
#ifdef CONFIG_UNCACHED_MAPPING
                "            : 0x%08lx - 0x%08lx   (%4ld MB) (uncached)\n"
#endif
                "      .init : 0x%08lx - 0x%08lx   (%4ld kB)\n"
                "      .data : 0x%08lx - 0x%08lx   (%4ld kB)\n"
                "      .text : 0x%08lx - 0x%08lx   (%4ld kB)\n",
                FIXADDR_START, FIXADDR_TOP,
                (FIXADDR_TOP - FIXADDR_START) >> 10,

#ifdef CONFIG_HIGHMEM
                PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE,
                (LAST_PKMAP*PAGE_SIZE) >> 10,
#endif

                (unsigned long)VMALLOC_START, VMALLOC_END,
                (VMALLOC_END - VMALLOC_START) >> 20,

                (unsigned long)memory_start, (unsigned long)high_memory,
                ((unsigned long)high_memory - (unsigned long)memory_start) >> 20,

#ifdef CONFIG_UNCACHED_MAPPING
                uncached_start, uncached_end, uncached_size >> 20,
#endif

                (unsigned long)&__init_begin, (unsigned long)&__init_end,
                ((unsigned long)&__init_end -
                 (unsigned long)&__init_begin) >> 10,

                (unsigned long)&_etext, (unsigned long)&_edata,
                ((unsigned long)&_edata - (unsigned long)&_etext) >> 10,

                (unsigned long)&_text, (unsigned long)&_etext,
                ((unsigned long)&_etext - (unsigned long)&_text) >> 10);

        mem_init_done = 1;
}

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

#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

#ifdef CONFIG_MEMORY_HOTREMOVE
int arch_remove_memory(u64 start, u64 size)
{
        unsigned long start_pfn = start >> PAGE_SHIFT;
        unsigned long nr_pages = size >> PAGE_SHIFT;
        struct zone *zone;
        int ret;

        zone = page_zone(pfn_to_page(start_pfn));
        ret = __remove_pages(zone, start_pfn, nr_pages);
        if (unlikely(ret))
                pr_warn("%s: Failed, __remove_pages() == %d\n", __func__,
                        ret);

        return ret;
}
#endif
#endif /* CONFIG_MEMORY_HOTPLUG */