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init.c

/*
 * 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) 1994 - 2000 Ralf Baechle
 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
 * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
 * Copyright (C) 2000 MIPS Technologies, Inc.  All rights reserved.
 */
#include <linux/bug.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/pagemap.h>
#include <linux/ptrace.h>
#include <linux/mman.h>
#include <linux/mm.h>
#include <linux/bootmem.h>
#include <linux/highmem.h>
#include <linux/swap.h>
#include <linux/proc_fs.h>
#include <linux/pfn.h>
#include <linux/hardirq.h>

#include <asm/asm-offsets.h>
#include <asm/bootinfo.h>
#include <asm/cachectl.h>
#include <asm/cpu.h>
#include <asm/dma.h>
#include <asm/kmap_types.h>
#include <asm/mmu_context.h>
#include <asm/sections.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/tlb.h>
#include <asm/fixmap.h>

/* Atomicity and interruptability */
#ifdef CONFIG_MIPS_MT_SMTC

#include <asm/mipsmtregs.h>

#define ENTER_CRITICAL(flags) \
      { \
      unsigned int mvpflags; \
      local_irq_save(flags);\
      mvpflags = dvpe()
#define EXIT_CRITICAL(flags) \
      evpe(mvpflags); \
      local_irq_restore(flags); \
      }
#else

#define ENTER_CRITICAL(flags) local_irq_save(flags)
#define EXIT_CRITICAL(flags) local_irq_restore(flags)

#endif /* CONFIG_MIPS_MT_SMTC */

DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);

/*
 * We have up to 8 empty zeroed pages so we can map one of the right colour
 * when needed.  This is necessary only on R4000 / R4400 SC and MC versions
 * where we have to avoid VCED / VECI exceptions for good performance at
 * any price.  Since page is never written to after the initialization we
 * don't have to care about aliases on other CPUs.
 */
unsigned long empty_zero_page, zero_page_mask;
EXPORT_SYMBOL_GPL(empty_zero_page);

/*
 * Not static inline because used by IP27 special magic initialization code
 */
unsigned long setup_zero_pages(void)
{
      unsigned int order;
      unsigned long size;
      struct page *page;

      if (cpu_has_vce)
            order = 3;
      else
            order = 0;

      empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
      if (!empty_zero_page)
            panic("Oh boy, that early out of memory?");

      page = virt_to_page((void *)empty_zero_page);
      split_page(page, order);
      while (page < virt_to_page((void *)(empty_zero_page + (PAGE_SIZE << order)))) {
            SetPageReserved(page);
            page++;
      }

      size = PAGE_SIZE << order;
      zero_page_mask = (size - 1) & PAGE_MASK;

      return 1UL << order;
}

#ifdef CONFIG_MIPS_MT_SMTC
static pte_t *kmap_coherent_pte;
static void __init kmap_coherent_init(void)
{
      unsigned long vaddr;

      /* cache the first coherent kmap pte */
      vaddr = __fix_to_virt(FIX_CMAP_BEGIN);
      kmap_coherent_pte = kmap_get_fixmap_pte(vaddr);
}
#else
static inline void kmap_coherent_init(void) {}
#endif

void *kmap_coherent(struct page *page, unsigned long addr)
{
      enum fixed_addresses idx;
      unsigned long vaddr, flags, entrylo;
      unsigned long old_ctx;
      pte_t pte;
      int tlbidx;

      BUG_ON(Page_dcache_dirty(page));

      inc_preempt_count();
      idx = (addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1);
#ifdef CONFIG_MIPS_MT_SMTC
      idx += FIX_N_COLOURS * smp_processor_id() +
            (in_interrupt() ? (FIX_N_COLOURS * NR_CPUS) : 0);
#else
      idx += in_interrupt() ? FIX_N_COLOURS : 0;
#endif
      vaddr = __fix_to_virt(FIX_CMAP_END - idx);
      pte = mk_pte(page, PAGE_KERNEL);
#if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)
      entrylo = pte.pte_high;
#else
      entrylo = pte_val(pte) >> 6;
#endif

      ENTER_CRITICAL(flags);
      old_ctx = read_c0_entryhi();
      write_c0_entryhi(vaddr & (PAGE_MASK << 1));
      write_c0_entrylo0(entrylo);
      write_c0_entrylo1(entrylo);
#ifdef CONFIG_MIPS_MT_SMTC
      set_pte(kmap_coherent_pte - (FIX_CMAP_END - idx), pte);
      /* preload TLB instead of local_flush_tlb_one() */
      mtc0_tlbw_hazard();
      tlb_probe();
      tlb_probe_hazard();
      tlbidx = read_c0_index();
      mtc0_tlbw_hazard();
      if (tlbidx < 0)
            tlb_write_random();
      else
            tlb_write_indexed();
#else
      tlbidx = read_c0_wired();
      write_c0_wired(tlbidx + 1);
      write_c0_index(tlbidx);
      mtc0_tlbw_hazard();
      tlb_write_indexed();
#endif
      tlbw_use_hazard();
      write_c0_entryhi(old_ctx);
      EXIT_CRITICAL(flags);

      return (void*) vaddr;
}

#define UNIQUE_ENTRYHI(idx) (CKSEG0 + ((idx) << (PAGE_SHIFT + 1)))

void kunmap_coherent(void)
{
#ifndef CONFIG_MIPS_MT_SMTC
      unsigned int wired;
      unsigned long flags, old_ctx;

      ENTER_CRITICAL(flags);
      old_ctx = read_c0_entryhi();
      wired = read_c0_wired() - 1;
      write_c0_wired(wired);
      write_c0_index(wired);
      write_c0_entryhi(UNIQUE_ENTRYHI(wired));
      write_c0_entrylo0(0);
      write_c0_entrylo1(0);
      mtc0_tlbw_hazard();
      tlb_write_indexed();
      tlbw_use_hazard();
      write_c0_entryhi(old_ctx);
      EXIT_CRITICAL(flags);
#endif
      dec_preempt_count();
      preempt_check_resched();
}

void copy_user_highpage(struct page *to, struct page *from,
      unsigned long vaddr, struct vm_area_struct *vma)
{
      void *vfrom, *vto;

      vto = kmap_atomic(to, KM_USER1);
      if (cpu_has_dc_aliases &&
          page_mapped(from) && !Page_dcache_dirty(from)) {
            vfrom = kmap_coherent(from, vaddr);
            copy_page(vto, vfrom);
            kunmap_coherent();
      } else {
            vfrom = kmap_atomic(from, KM_USER0);
            copy_page(vto, vfrom);
            kunmap_atomic(vfrom, KM_USER0);
      }
      if ((!cpu_has_ic_fills_f_dc) ||
          pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK))
            flush_data_cache_page((unsigned long)vto);
      kunmap_atomic(vto, KM_USER1);
      /* Make sure this page is cleared on other CPU's too before using it */
      smp_wmb();
}

void copy_to_user_page(struct vm_area_struct *vma,
      struct page *page, unsigned long vaddr, void *dst, const void *src,
      unsigned long len)
{
      if (cpu_has_dc_aliases &&
          page_mapped(page) && !Page_dcache_dirty(page)) {
            void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
            memcpy(vto, src, len);
            kunmap_coherent();
      } else {
            memcpy(dst, src, len);
            if (cpu_has_dc_aliases)
                  SetPageDcacheDirty(page);
      }
      if ((vma->vm_flags & VM_EXEC) && !cpu_has_ic_fills_f_dc)
            flush_cache_page(vma, vaddr, page_to_pfn(page));
}

void copy_from_user_page(struct vm_area_struct *vma,
      struct page *page, unsigned long vaddr, void *dst, const void *src,
      unsigned long len)
{
      if (cpu_has_dc_aliases &&
          page_mapped(page) && !Page_dcache_dirty(page)) {
            void *vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
            memcpy(dst, vfrom, len);
            kunmap_coherent();
      } else {
            memcpy(dst, src, len);
            if (cpu_has_dc_aliases)
                  SetPageDcacheDirty(page);
      }
}

void __init fixrange_init(unsigned long start, unsigned long end,
      pgd_t *pgd_base)
{
#if defined(CONFIG_HIGHMEM) || defined(CONFIG_MIPS_MT_SMTC)
      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);
                              set_pmd(pmd, __pmd((unsigned long)pte));
                              BUG_ON(pte != pte_offset_kernel(pmd, 0));
                        }
                        vaddr += PMD_SIZE;
                  }
                  k = 0;
            }
            j = 0;
      }
#endif
}

#ifndef CONFIG_NEED_MULTIPLE_NODES
static int __init page_is_ram(unsigned long pagenr)
{
      int i;

      for (i = 0; i < boot_mem_map.nr_map; i++) {
            unsigned long addr, end;

            if (boot_mem_map.map[i].type != BOOT_MEM_RAM)
                  /* not usable memory */
                  continue;

            addr = PFN_UP(boot_mem_map.map[i].addr);
            end = PFN_DOWN(boot_mem_map.map[i].addr +
                         boot_mem_map.map[i].size);

            if (pagenr >= addr && pagenr < end)
                  return 1;
      }

      return 0;
}

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

      pagetable_init();

#ifdef CONFIG_HIGHMEM
      kmap_init();
#endif
      kmap_coherent_init();

#ifdef CONFIG_ZONE_DMA
      max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
#endif
#ifdef CONFIG_ZONE_DMA32
      max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
#endif
      max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
      lastpfn = max_low_pfn;
#ifdef CONFIG_HIGHMEM
      max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
      lastpfn = highend_pfn;

      if (cpu_has_dc_aliases && max_low_pfn != highend_pfn) {
            printk(KERN_WARNING "This processor doesn't support highmem."
                   " %ldk highmem ignored\n",
                   (highend_pfn - max_low_pfn) << (PAGE_SHIFT - 10));
            max_zone_pfns[ZONE_HIGHMEM] = max_low_pfn;
            lastpfn = max_low_pfn;
      }
#endif

      free_area_init_nodes(max_zone_pfns);
}

#ifdef CONFIG_64BIT
static struct kcore_list kcore_kseg0;
#endif

void __init mem_init(void)
{
      unsigned long codesize, reservedpages, datasize, initsize;
      unsigned long tmp, ram;

#ifdef CONFIG_HIGHMEM
#ifdef CONFIG_DISCONTIGMEM
#error "CONFIG_HIGHMEM and CONFIG_DISCONTIGMEM dont work together yet"
#endif
      max_mapnr = highend_pfn;
#else
      max_mapnr = max_low_pfn;
#endif
      high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);

      totalram_pages += free_all_bootmem();
      totalram_pages -= setup_zero_pages();     /* Setup zeroed pages.  */

      reservedpages = ram = 0;
      for (tmp = 0; tmp < max_low_pfn; tmp++)
            if (page_is_ram(tmp)) {
                  ram++;
                  if (PageReserved(pfn_to_page(tmp)))
                        reservedpages++;
            }
      num_physpages = ram;

#ifdef CONFIG_HIGHMEM
      for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
            struct page *page = pfn_to_page(tmp);

            if (!page_is_ram(tmp)) {
                  SetPageReserved(page);
                  continue;
            }
            ClearPageReserved(page);
            init_page_count(page);
            __free_page(page);
            totalhigh_pages++;
      }
      totalram_pages += totalhigh_pages;
      num_physpages += totalhigh_pages;
#endif

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

#ifdef CONFIG_64BIT
      if ((unsigned long) &_text > (unsigned long) CKSEG0)
            /* The -4 is a hack so that user tools don't have to handle
               the overflow.  */
            kclist_add(&kcore_kseg0, (void *) CKSEG0,
                        0x80000000 - 4, KCORE_TEXT);
#endif

      printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
             "%ldk reserved, %ldk data, %ldk init, %ldk highmem)\n",
             nr_free_pages() << (PAGE_SHIFT-10),
             ram << (PAGE_SHIFT-10),
             codesize >> 10,
             reservedpages << (PAGE_SHIFT-10),
             datasize >> 10,
             initsize >> 10,
             (unsigned long) (totalhigh_pages << (PAGE_SHIFT-10)));
}
#endif /* !CONFIG_NEED_MULTIPLE_NODES */

void free_init_pages(const char *what, unsigned long begin, unsigned long end)
{
      unsigned long pfn;

      for (pfn = PFN_UP(begin); pfn < PFN_DOWN(end); pfn++) {
            struct page *page = pfn_to_page(pfn);
            void *addr = phys_to_virt(PFN_PHYS(pfn));

            ClearPageReserved(page);
            init_page_count(page);
            memset(addr, POISON_FREE_INITMEM, PAGE_SIZE);
            __free_page(page);
            totalram_pages++;
      }
      printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
}

#ifdef CONFIG_BLK_DEV_INITRD
void free_initrd_mem(unsigned long start, unsigned long end)
{
      free_init_pages("initrd memory",
                  virt_to_phys((void *)start),
                  virt_to_phys((void *)end));
}
#endif

void __init_refok free_initmem(void)
{
      prom_free_prom_memory();
      free_init_pages("unused kernel memory",
                  __pa_symbol(&__init_begin),
                  __pa_symbol(&__init_end));
}

unsigned long pgd_current[NR_CPUS];
/*
 * On 64-bit we've got three-level pagetables with a slightly
 * different layout ...
 */
#define __page_aligned(order) __attribute__((__aligned__(PAGE_SIZE<<order)))

/*
 * gcc 3.3 and older have trouble determining that PTRS_PER_PGD and PGD_ORDER
 * are constants.  So we use the variants from asm-offset.h until that gcc
 * will officially be retired.
 */
pgd_t swapper_pg_dir[_PTRS_PER_PGD] __page_aligned(_PGD_ORDER);
#ifdef CONFIG_64BIT
pmd_t invalid_pmd_table[PTRS_PER_PMD] __page_aligned(PMD_ORDER);
#endif
pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned(PTE_ORDER);

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