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/*

 * Initialize MMU support.

 *

 * Copyright (C) 1998-2002 Hewlett-Packard Co

 *      David Mosberger-Tang <davidm@hpl.hp.com>

 */

#include <linux/config.h>

#include <linux/module.h>

#include <linux/kernel.h>

#include <linux/init.h>

#include <linux/bootmem.h>

#include <linux/mm.h>

#include <linux/personality.h>

#include <linux/reboot.h>

#include <linux/slab.h>

#include <linux/swap.h>

#include <linux/efi.h>

#include <linux/mmzone.h>

#include <asm/bitops.h>

#include <asm/dma.h>

#include <asm/ia32.h>

#include <asm/io.h>

#include <asm/machvec.h>

#include <asm/numa.h>

#include <asm/pgalloc.h>

#include <asm/sal.h>

#include <asm/system.h>

#include <asm/uaccess.h>

#include <asm/mca.h>

/* References to section boundaries: */

extern char _stext, _etext, _edata, __init_begin, __init_end;

extern void ia64_tlb_init (void);

extern int  filter_rsvd_memory (unsigned long, unsigned long, void *);

/* Note - may be changed by platform_setup */

unsigned long MAX_DMA_ADDRESS = PAGE_OFFSET + 0x100000000UL;

#define LARGE_GAP 0x40000000 /* Use virtual mem map if a hole is > than this */

static unsigned long totalram_pages, reserved_pages;

struct page *zero_page_memmap_ptr;              /* map entry for zero page */

unsigned long vmalloc_end = VMALLOC_END_INIT;

static struct page *vmem_map;

static unsigned long num_dma_physpages;

int

do_check_pgt_cache (int low, int high)

{

        int freed = 0;

        if (pgtable_cache_size > high) {

                do {

                        if (pgd_quicklist)

                                free_page((unsigned long)pgd_alloc_one_fast(0)), ++freed;

                        if (pmd_quicklist)

                                free_page((unsigned long)pmd_alloc_one_fast(0, 0)), ++freed;

                        if (pte_quicklist)

                                free_page((unsigned long)pte_alloc_one_fast(0, 0)), ++freed;

                } while (pgtable_cache_size > low);

        }

        return freed;

}

inline void

ia64_set_rbs_bot (void)

{

        unsigned long stack_size = current->rlim[RLIMIT_STACK].rlim_max & -16;

        if (stack_size > MAX_USER_STACK_SIZE)

                stack_size = MAX_USER_STACK_SIZE;

        current->thread.rbs_bot = STACK_TOP - stack_size;

}

/*

 * This performs some platform-dependent address space initialization.

 * On IA-64, we want to setup the VM area for the register backing

 * store (which grows upwards) and install the gateway page which is

 * used for signal trampolines, etc.

 */

void

ia64_init_addr_space (void)

{

        struct vm_area_struct *vma;

        ia64_set_rbs_bot();

        /*

         * If we're out of memory and kmem_cache_alloc() returns NULL, we simply ignore

         * the problem.  When the process attempts to write to the register backing store

         * for the first time, it will get a SEGFAULT in this case.

         */

        vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);

        if (vma) {

                vma->vm_mm = current->mm;

                vma->vm_start = current->thread.rbs_bot & PAGE_MASK;

                vma->vm_end = vma->vm_start + PAGE_SIZE;

                vma->vm_page_prot = PAGE_COPY;

                vma->vm_flags = VM_READ|VM_WRITE|VM_MAYREAD|VM_MAYWRITE|VM_GROWSUP;

                vma->vm_ops = NULL;

                vma->vm_pgoff = 0;

                vma->vm_file = NULL;

                vma->vm_private_data = NULL;

                insert_vm_struct(current->mm, vma);

        }

        /* map NaT-page at address zero to speed up speculative dereferencing of NULL: */

        if (!(current->personality & MMAP_PAGE_ZERO)) {

                vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);

                if (vma) {

                        memset(vma, 0, sizeof(*vma));

                        vma->vm_mm = current->mm;

                        vma->vm_end = PAGE_SIZE;

                        vma->vm_page_prot = __pgprot(pgprot_val(PAGE_READONLY) | _PAGE_MA_NAT);

                        vma->vm_flags = VM_READ | VM_MAYREAD | VM_IO | VM_RESERVED;

                        insert_vm_struct(current->mm, vma);

                }

        }

}

void

free_initmem (void)

{

        unsigned long addr, eaddr;

        addr = (unsigned long) ia64_imva(&__init_begin);

        eaddr = (unsigned long) ia64_imva(&__init_end);

        for (; addr < eaddr; addr += PAGE_SIZE) {

                clear_bit(PG_reserved, &virt_to_page((void *)addr)->flags);

                set_page_count(virt_to_page((void *)addr), 1);

                free_page(addr);

                ++totalram_pages;

        }

        printk(KERN_INFO "Freeing unused kernel memory: %ldkB freed\n",

                (&__init_end - &__init_begin) >> 10);

}

void

free_initrd_mem(unsigned long start, unsigned long end)

{

        /*

         * EFI uses 4KB pages while the kernel can use 4KB  or bigger.

         * Thus EFI and the kernel may have different page sizes. It is

         * therefore possible to have the initrd share the same page as

         * the end of the kernel (given current setup).

         *

         * To avoid freeing/using the wrong page (kernel sized) we:

         *      - align up the beginning of initrd

         *      - align down the end of initrd

         *

         *  |             |

         *  |=============| a000

         *  |             |

         *  |             |

         *  |             | 9000

         *  |/////////////|

         *  |/////////////|

         *  |=============| 8000

         *  |///INITRD////|

         *  |/////////////|

         *  |/////////////| 7000

         *  |             |

         *  |KKKKKKKKKKKKK|

         *  |=============| 6000

         *  |KKKKKKKKKKKKK|

         *  |KKKKKKKKKKKKK|

         *  K=kernel using 8KB pages

         *

         * In this example, we must free page 8000 ONLY. So we must align up

         * initrd_start and keep initrd_end as is.

         */

        start = PAGE_ALIGN(start);

        end = end & PAGE_MASK;

        if (start < end)

                printk(KERN_INFO "Freeing initrd memory: %ldkB freed\n", (end - start) >> 10);

        for (; start < end; start += PAGE_SIZE) {

                if (!VALID_PAGE(virt_to_page((void *)start)))

                        continue;

                clear_bit(PG_reserved, &virt_to_page((void *)start)->flags);

                set_page_count(virt_to_page((void *)start), 1);

                free_page(start);

                ++totalram_pages;

        }

}

void

si_meminfo (struct sysinfo *val)

{

        val->totalram = totalram_pages;

        val->sharedram = 0;

        val->freeram = nr_free_pages();

        val->bufferram = atomic_read(&buffermem_pages);

        val->totalhigh = 0;

        val->freehigh = 0;

        val->mem_unit = PAGE_SIZE;

        return;

}

void

show_mem(void)

{

        int i, reserved;

        int shared, cached;

        pg_data_t *pgdat;

        char *tchar = (numnodes > 1) ? "\t" : "";

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

        show_free_areas();

        printk("Free swap:       %6dkB\n", nr_swap_pages<<(PAGE_SHIFT-10));

        for_each_pgdat(pgdat) {

                reserved=0;

                cached=0;

                shared=0;

                if (numnodes > 1)

                        printk("Node ID: %d\n", pgdat->node_id);

                for(i = 0; i < pgdat->node_size; i++) {

                        if (!VALID_PAGE(pgdat->node_mem_map+i))

                                continue;

                        if (PageReserved(pgdat->node_mem_map+i))

                                reserved++;

                        else if (PageSwapCache(pgdat->node_mem_map+i))

                                cached++;

                        else if (page_count(pgdat->node_mem_map + i))

                                shared += page_count(pgdat->node_mem_map + i) - 1;

                }

                printk("%s%ld pages of RAM\n", tchar, pgdat->node_size);

                printk("%s%d reserved pages\n", tchar, reserved);

                printk("%s%d pages shared\n", tchar, shared);

                printk("%s%d pages swap cached\n", tchar, cached);

        }

        printk("Total of %ld pages in page table cache\n", pgtable_cache_size);

        show_buffers();

        printk("%d free buffer pages\n", nr_free_buffer_pages());

}

/*

 * This is like put_dirty_page() but installs a clean page with PAGE_GATE protection

 * (execute-only, typically).

 */

struct page *

put_gate_page (struct page *page, unsigned long address)

{

        pgd_t *pgd;

        pmd_t *pmd;

        pte_t *pte;

        if (!PageReserved(page))

                printk(KERN_ERR "put_gate_page: gate page at 0x%p not in reserved memory\n",

                       page_address(page));

        pgd = pgd_offset_k(address);            /* note: this is NOT pgd_offset()! */

        spin_lock(&init_mm.page_table_lock);

        {

                pmd = pmd_alloc(&init_mm, pgd, address);

                if (!pmd)

                        goto out;

                pte = pte_alloc(&init_mm, pmd, address);

                if (!pte)

                        goto out;

                if (!pte_none(*pte)) {

                        pte_ERROR(*pte);

                        goto out;

                }

                flush_page_to_ram(page);

                set_pte(pte, mk_pte(page, PAGE_GATE));

        }

  out:  spin_unlock(&init_mm.page_table_lock);

        /* no need for flush_tlb */

        return page;

}

void __init

ia64_mmu_init (void *my_cpu_data)

{

        unsigned long psr, rid, pta, impl_va_bits;

        extern void __init tlb_init (void);

#ifdef CONFIG_IA64_MCA

        int cpu;

#endif

#ifdef CONFIG_DISABLE_VHPT

#       define VHPT_ENABLE_BIT  0

#else

#       define VHPT_ENABLE_BIT  1

#endif

        /*

         * Set up the kernel identity mapping for regions 6 and 5.  The mapping for region

         * 7 is setup up in _start().

         */

        psr = ia64_clear_ic();

        rid = ia64_rid(IA64_REGION_ID_KERNEL, __IA64_UNCACHED_OFFSET);

        ia64_set_rr(__IA64_UNCACHED_OFFSET, (rid << 8) | (IA64_GRANULE_SHIFT << 2));

        rid = ia64_rid(IA64_REGION_ID_KERNEL, VMALLOC_START);

        ia64_set_rr(VMALLOC_START, (rid << 8) | (PAGE_SHIFT << 2) | 1);

        /* ensure rr6 is up-to-date before inserting the PERCPU_ADDR translation: */

        ia64_srlz_d();

        ia64_itr(0x2, IA64_TR_PERCPU_DATA, PERCPU_ADDR,

                 pte_val(mk_pte_phys(__pa(my_cpu_data), PAGE_KERNEL)), PAGE_SHIFT);

        ia64_set_psr(psr);

        ia64_srlz_i();

        /*

         * Check if the virtually mapped linear page table (VMLPT) overlaps with a mapped

         * address space.  The IA-64 architecture guarantees that at least 50 bits of

         * virtual address space are implemented but if we pick a large enough page size

         * (e.g., 64KB), the mapped address space is big enough that it will overlap with

         * VMLPT.  I assume that once we run on machines big enough to warrant 64KB pages,

         * IMPL_VA_MSB will be significantly bigger, so this is unlikely to become a

         * problem in practice.  Alternatively, we could truncate the top of the mapped

         * address space to not permit mappings that would overlap with the VMLPT.

         * --davidm 00/12/06

         */

#       define pte_bits                 3

#       define mapped_space_bits        (3*(PAGE_SHIFT - pte_bits) + PAGE_SHIFT)

        /*

         * The virtual page table has to cover the entire implemented address space within

         * a region even though not all of this space may be mappable.  The reason for

         * this is that the Access bit and Dirty bit fault handlers perform

         * non-speculative accesses to the virtual page table, so the address range of the

         * virtual page table itself needs to be covered by virtual page table.

         */

#       define vmlpt_bits               (impl_va_bits - PAGE_SHIFT + pte_bits)

#       define POW2(n)                  (1ULL << (n))

        impl_va_bits = ffz(~(local_cpu_data->unimpl_va_mask | (7UL << 61)));

        if (impl_va_bits < 51 || impl_va_bits > 61)

                panic("CPU has bogus IMPL_VA_MSB value of %lu!\n", impl_va_bits - 1);

        /* place the VMLPT at the end of each page-table mapped region: */

        pta = POW2(61) - POW2(vmlpt_bits);

        if (POW2(mapped_space_bits) >= pta)

                panic("mm/init: overlap between virtually mapped linear page table and "

                      "mapped kernel space!");

        /*

         * Set the (virtually mapped linear) page table address.  Bit

         * 8 selects between the short and long format, bits 2-7 the

         * size of the table, and bit 0 whether the VHPT walker is

         * enabled.

         */

        ia64_set_pta(pta | (0 << 8) | (vmlpt_bits << 2) | VHPT_ENABLE_BIT);

        ia64_tlb_init();

#ifdef  CONFIG_IA64_MCA

        cpu = smp_processor_id();

        /* mca handler uses cr.lid as key to pick the right entry */

        ia64_mca_tlb_list[cpu].cr_lid = ia64_get_lid();

        /* insert this percpu data information into our list for MCA recovery purposes */

        ia64_mca_tlb_list[cpu].percpu_paddr = pte_val(mk_pte_phys(__pa(my_cpu_data), PAGE_KERNEL));

        /* Also save per-cpu tlb flush recipe for use in physical mode mca handler */

        ia64_mca_tlb_list[cpu].ptce_base = local_cpu_data->ptce_base;

        ia64_mca_tlb_list[cpu].ptce_count[0] = local_cpu_data->ptce_count[0];

        ia64_mca_tlb_list[cpu].ptce_count[1] = local_cpu_data->ptce_count[1];

        ia64_mca_tlb_list[cpu].ptce_stride[0] = local_cpu_data->ptce_stride[0];

        ia64_mca_tlb_list[cpu].ptce_stride[1] = local_cpu_data->ptce_stride[1];

#endif

}

static int

create_mem_map_page_table (u64 start, u64 end, void *arg)

{

        unsigned long address, start_page, end_page, next_blk_page;

        unsigned long blk_start;

        struct page *map_start, *map_end;

        int node=0;

        pgd_t *pgd;

        pmd_t *pmd;

        pte_t *pte;

        /* should we use platform_map_nr here? */

        map_start = vmem_map + MAP_NR_DENSE(start);

        map_end   = vmem_map + MAP_NR_DENSE(end);

        start_page = (unsigned long) map_start & PAGE_MASK;

        end_page = PAGE_ALIGN((unsigned long) map_end);

        /* force the first iteration to get node id */

        blk_start = start;

        next_blk_page = 0;

        for (address = start_page; address < end_page; address += PAGE_SIZE) {

                /* if we went across a node boundary, get new nid */

                if (address >= next_blk_page) {

                        struct page *map_next_blk;

                        node = paddr_to_nid(__pa(blk_start));

                        /* get end addr of this memblk as next blk_start */

                        blk_start = (unsigned long) __va(min(end, memblk_endpaddr(__pa(blk_start))));

                        map_next_blk = vmem_map + MAP_NR_DENSE(blk_start);

                        next_blk_page = PAGE_ALIGN((unsigned long) map_next_blk);

                }

                pgd = pgd_offset_k(address);

                if (pgd_none(*pgd))

                        pgd_populate(&init_mm, pgd, alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE));

                pmd = pmd_offset(pgd, address);

                if (pmd_none(*pmd))

                        pmd_populate(&init_mm, pmd, alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE));

                pte = pte_offset(pmd, address);

                if (pte_none(*pte))

                        set_pte(pte, mk_pte_phys(__pa(alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE)),

                                                 PAGE_KERNEL));

        }

        return 0;

}

struct memmap_init_callback_data {

        memmap_init_callback_t *memmap_init;

        struct page *start;

        struct page *end;

        int zone;

        int highmem;

};

struct memmap_count_callback_data {

        int node;

        unsigned long num_physpages;

        unsigned long num_dma_physpages;

        unsigned long min_pfn;

        unsigned long max_pfn;

} cdata;

static int

virtual_memmap_init (u64 start, u64 end, void *arg)

{

        struct memmap_init_callback_data *args;

        struct page *map_start, *map_end;

        args = (struct memmap_init_callback_data *) arg;

        /* Should we use platform_map_nr here? */

        map_start = mem_map + MAP_NR_DENSE(start);

        map_end   = mem_map + MAP_NR_DENSE(end);

        if (map_start < args->start)

                map_start = args->start;

        if (map_end > args->end)

                map_end = args->end;

        /*

         * We have to initialize "out of bounds" struct page elements

         * that fit completely on the same pages that were allocated

         * for the "in bounds" elements because they may be referenced

         * later (and found to be "reserved").

         */

        map_start -= ((unsigned long) map_start & (PAGE_SIZE - 1))

                        / sizeof(struct page);

        map_end += ((PAGE_ALIGN((unsigned long) map_end) -

                                (unsigned long) map_end)

                        / sizeof(struct page));

        if (map_start < map_end)

                (*args->memmap_init)(map_start, map_end, args->zone,

                                     page_to_phys(map_start), args->highmem);

        return 0;

}

unsigned long

arch_memmap_init (memmap_init_callback_t *memmap_init, struct page *start,

        struct page *end, int zone, unsigned long start_paddr, int highmem)

{

        if (!vmem_map)

                memmap_init(start,end,zone,page_to_phys(start),highmem);

        else {

                struct memmap_init_callback_data args;

                args.memmap_init = memmap_init;

                args.start = start;

                args.end = end;

                args.zone = zone;

                args.highmem = highmem;

                efi_memmap_walk(virtual_memmap_init, &args);

        }

        return page_to_phys(end-1) + PAGE_SIZE;;

}

int

ia64_page_valid (struct page *page)

{

        char byte;

        return     (__get_user(byte, (char *) page) == 0)

                && (__get_user(byte, (char *) (page + 1) - 1) == 0);

}

#define GRANULEROUNDDOWN(n) ((n) & ~(IA64_GRANULE_SIZE-1))

#define GRANULEROUNDUP(n) (((n)+IA64_GRANULE_SIZE-1) & ~(IA64_GRANULE_SIZE-1))

#define ORDERROUNDDOWN(n) ((n) & ~((PAGE_SIZE<<MAX_ORDER)-1))

static int

count_pages (u64 start, u64 end, int node)

{

        start = __pa(start);

        end = __pa(end);

        if (node == cdata.node) {

                cdata.num_physpages += (end - start) >> PAGE_SHIFT;

                if (start <= __pa(MAX_DMA_ADDRESS))

                        cdata.num_dma_physpages += (min(end, __pa(MAX_DMA_ADDRESS)) - start) >> PAGE_SHIFT;

                start = GRANULEROUNDDOWN(__pa(start));

                start = ORDERROUNDDOWN(start);

                end = GRANULEROUNDUP(__pa(end));

                cdata.max_pfn = max(cdata.max_pfn, end >> PAGE_SHIFT);

                cdata.min_pfn = min(cdata.min_pfn, start >> PAGE_SHIFT);

        }

        return 0;

}

static int

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;

}

/*

 * Set up the page tables.

 */

void

paging_init (void)

{

        unsigned long max_dma;

        unsigned long zones_size[MAX_NR_ZONES];

        unsigned long zholes_size[MAX_NR_ZONES];

        unsigned long max_gap;

        int node;

        /* initialize mem_map[] */

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

        max_gap = 0;

        efi_memmap_walk(find_largest_hole, (u64 *)&max_gap);

        for (node=0; node < numnodes; node++) {

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

                memset(zholes_size, 0, sizeof(zholes_size));

                memset(&cdata, 0, sizeof(cdata));

                cdata.node = node;

                cdata.min_pfn = ~0;

                efi_memmap_walk(filter_rsvd_memory, count_pages);

                num_dma_physpages += cdata.num_dma_physpages;

                num_physpages += cdata.num_physpages;

                if (cdata.min_pfn >= max_dma) {

                        zones_size[ZONE_NORMAL] = cdata.max_pfn - cdata.min_pfn;

                        zholes_size[ZONE_NORMAL] = cdata.max_pfn - cdata.min_pfn - cdata.num_physpages;

                } else if (cdata.max_pfn < max_dma) {

                        zones_size[ZONE_DMA] = cdata.max_pfn - cdata.min_pfn;

                        zholes_size[ZONE_DMA] = cdata.max_pfn - cdata.min_pfn - cdata.num_dma_physpages;

                } else {

                        zones_size[ZONE_DMA] = max_dma - cdata.min_pfn;

                        zholes_size[ZONE_DMA] = zones_size[ZONE_DMA] - cdata.num_dma_physpages;

                        zones_size[ZONE_NORMAL] = cdata.max_pfn - max_dma;

                        zholes_size[ZONE_NORMAL] = zones_size[ZONE_NORMAL] - (cdata.num_physpages - cdata.num_dma_physpages);

                }

                if (numnodes == 1 && max_gap < LARGE_GAP) {

                        vmem_map = (struct page *)0;

                        zones_size[ZONE_DMA] += cdata.min_pfn;

                        zholes_size[ZONE_DMA] += cdata.min_pfn;

                        free_area_init_core(0, NODE_DATA(node), &mem_map, zones_size, 0, zholes_size, NULL);

                } else {

                        /* allocate virtual mem_map */

                        if (node == 0) {

                                unsigned long map_size;

                                map_size = PAGE_ALIGN(max_low_pfn*sizeof(struct page));

                                vmalloc_end -= map_size;

                                mem_map = vmem_map = (struct page *) vmalloc_end;

                                efi_memmap_walk(create_mem_map_page_table, 0);

                                printk(KERN_INFO "Virtual mem_map starts at 0x%p\n", mem_map);

                        }

                        free_area_init_node(node, NODE_DATA(node), vmem_map+cdata.min_pfn, zones_size,

                                cdata.min_pfn<<PAGE_SHIFT, zholes_size);

                }

        }

        zero_page_memmap_ptr = virt_to_page(ia64_imva(empty_zero_page));

}

static int

count_reserved_pages (u64 start, u64 end, void *arg)

{

        unsigned long num_reserved = 0;

        struct page *pg;

        for (pg = virt_to_page((void *)start); pg < virt_to_page((void *)end); ++pg)

                if (PageReserved(pg))

                        ++num_reserved;

        reserved_pages += num_reserved;

        return 0;

}

void

mem_init (void)

{

        extern char __start_gate_section[];

        long codesize, datasize, initsize;

        unsigned long num_pgt_pages;

        pg_data_t *pgdat;

#ifdef CONFIG_PCI

        /*

         * This needs to be called _after_ the command line has been parsed but _before_

         * any drivers that may need the PCI DMA interface are initialized or bootmem has

         * been freed.

         */

        platform_pci_dma_init();

#endif

        if (!mem_map)

                BUG();

        max_mapnr = max_low_pfn;

        high_memory = __va(max_low_pfn * PAGE_SIZE);

        for_each_pgdat(pgdat)

                totalram_pages += free_all_bootmem_node(pgdat);