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init.c

/*
 *  linux/arch/sparc/mm/init.c
 *
 *  Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
 *  Copyright (C) 1995 Eddie C. Dost (ecd@skynet.be)
 *  Copyright (C) 1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
 *  Copyright (C) 2000 Anton Blanchard (anton@samba.org)
 */

#include <linux/module.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/ptrace.h>
#include <linux/mman.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/initrd.h>
#include <linux/init.h>
#include <linux/highmem.h>
#include <linux/bootmem.h>
#include <linux/pagemap.h>

#include <asm/system.h>
#include <asm/vac-ops.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/vaddrs.h>
#include <asm/pgalloc.h>      /* bug in asm-generic/tlb.h: check_pgt_cache */
#include <asm/tlb.h>
#include <asm/prom.h>

DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);

unsigned long *sparc_valid_addr_bitmap;

unsigned long phys_base;
unsigned long pfn_base;

unsigned long page_kernel;

struct sparc_phys_banks sp_banks[SPARC_PHYS_BANKS+1];
unsigned long sparc_unmapped_base;

struct pgtable_cache_struct pgt_quicklists;

/* References to section boundaries */
extern char __init_begin, __init_end, _start, _end, etext , edata;

/* Initial ramdisk setup */
extern unsigned int sparc_ramdisk_image;
extern unsigned int sparc_ramdisk_size;

unsigned long highstart_pfn, highend_pfn;

pte_t *kmap_pte;
pgprot_t kmap_prot;

#define kmap_get_fixmap_pte(vaddr) \
      pte_offset_kernel(pmd_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr))

void __init kmap_init(void)
{
      /* cache the first kmap pte */
      kmap_pte = kmap_get_fixmap_pte(__fix_to_virt(FIX_KMAP_BEGIN));
      kmap_prot = __pgprot(SRMMU_ET_PTE | SRMMU_PRIV | SRMMU_CACHE);
}

void show_mem(void)
{
      printk("Mem-info:\n");
      show_free_areas();
      printk("Free swap:       %6ldkB\n",
             nr_swap_pages << (PAGE_SHIFT-10));
      printk("%ld pages of RAM\n", totalram_pages);
      printk("%ld free pages\n", nr_free_pages());
#if 0 /* undefined pgtable_cache_size, pgd_cache_size */
      printk("%ld pages in page table cache\n",pgtable_cache_size);
#ifndef CONFIG_SMP
      if (sparc_cpu_model == sun4m || sparc_cpu_model == sun4d)
            printk("%ld entries in page dir cache\n",pgd_cache_size);
#endif      
#endif
}

void __init sparc_context_init(int numctx)
{
      int ctx;

      ctx_list_pool = __alloc_bootmem(numctx * sizeof(struct ctx_list), SMP_CACHE_BYTES, 0UL);

      for(ctx = 0; ctx < numctx; ctx++) {
            struct ctx_list *clist;

            clist = (ctx_list_pool + ctx);
            clist->ctx_number = ctx;
            clist->ctx_mm = NULL;
      }
      ctx_free.next = ctx_free.prev = &ctx_free;
      ctx_used.next = ctx_used.prev = &ctx_used;
      for(ctx = 0; ctx < numctx; ctx++)
            add_to_free_ctxlist(ctx_list_pool + ctx);
}

extern unsigned long cmdline_memory_size;
unsigned long last_valid_pfn;

unsigned long calc_highpages(void)
{
      int i;
      int nr = 0;

      for (i = 0; sp_banks[i].num_bytes != 0; i++) {
            unsigned long start_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
            unsigned long end_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;

            if (end_pfn <= max_low_pfn)
                  continue;

            if (start_pfn < max_low_pfn)
                  start_pfn = max_low_pfn;

            nr += end_pfn - start_pfn;
      }

      return nr;
}

static unsigned long calc_max_low_pfn(void)
{
      int i;
      unsigned long tmp = pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT);
      unsigned long curr_pfn, last_pfn;

      last_pfn = (sp_banks[0].base_addr + sp_banks[0].num_bytes) >> PAGE_SHIFT;
      for (i = 1; sp_banks[i].num_bytes != 0; i++) {
            curr_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;

            if (curr_pfn >= tmp) {
                  if (last_pfn < tmp)
                        tmp = last_pfn;
                  break;
            }

            last_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
      }

      return tmp;
}

unsigned long __init bootmem_init(unsigned long *pages_avail)
{
      unsigned long bootmap_size, start_pfn;
      unsigned long end_of_phys_memory = 0UL;
      unsigned long bootmap_pfn, bytes_avail, size;
      int i;

      bytes_avail = 0UL;
      for (i = 0; sp_banks[i].num_bytes != 0; i++) {
            end_of_phys_memory = sp_banks[i].base_addr +
                  sp_banks[i].num_bytes;
            bytes_avail += sp_banks[i].num_bytes;
            if (cmdline_memory_size) {
                  if (bytes_avail > cmdline_memory_size) {
                        unsigned long slack = bytes_avail - cmdline_memory_size;

                        bytes_avail -= slack;
                        end_of_phys_memory -= slack;

                        sp_banks[i].num_bytes -= slack;
                        if (sp_banks[i].num_bytes == 0) {
                              sp_banks[i].base_addr = 0xdeadbeef;
                        } else {
                              sp_banks[i+1].num_bytes = 0;
                              sp_banks[i+1].base_addr = 0xdeadbeef;
                        }
                        break;
                  }
            }
      }

      /* Start with page aligned address of last symbol in kernel
       * image.  
       */
      start_pfn  = (unsigned long)__pa(PAGE_ALIGN((unsigned long) &_end));

      /* Now shift down to get the real physical page frame number. */
      start_pfn >>= PAGE_SHIFT;

      bootmap_pfn = start_pfn;

      max_pfn = end_of_phys_memory >> PAGE_SHIFT;

      max_low_pfn = max_pfn;
      highstart_pfn = highend_pfn = max_pfn;

      if (max_low_pfn > pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT)) {
            highstart_pfn = pfn_base + (SRMMU_MAXMEM >> PAGE_SHIFT);
            max_low_pfn = calc_max_low_pfn();
            printk(KERN_NOTICE "%ldMB HIGHMEM available.\n",
                calc_highpages() >> (20 - PAGE_SHIFT));
      }

#ifdef CONFIG_BLK_DEV_INITRD
      /* Now have to check initial ramdisk, so that bootmap does not overwrite it */
      if (sparc_ramdisk_image) {
            if (sparc_ramdisk_image >= (unsigned long)&_end - 2 * PAGE_SIZE)
                  sparc_ramdisk_image -= KERNBASE;
            initrd_start = sparc_ramdisk_image + phys_base;
            initrd_end = initrd_start + sparc_ramdisk_size;
            if (initrd_end > end_of_phys_memory) {
                  printk(KERN_CRIT "initrd extends beyond end of memory "
                               "(0x%016lx > 0x%016lx)\ndisabling initrd\n",
                         initrd_end, end_of_phys_memory);
                  initrd_start = 0;
            }
            if (initrd_start) {
                  if (initrd_start >= (start_pfn << PAGE_SHIFT) &&
                      initrd_start < (start_pfn << PAGE_SHIFT) + 2 * PAGE_SIZE)
                        bootmap_pfn = PAGE_ALIGN (initrd_end) >> PAGE_SHIFT;
            }
      }
#endif      
      /* Initialize the boot-time allocator. */
      bootmap_size = init_bootmem_node(NODE_DATA(0), bootmap_pfn, pfn_base,
                               max_low_pfn);

      /* Now register the available physical memory with the
       * allocator.
       */
      *pages_avail = 0;
      for (i = 0; sp_banks[i].num_bytes != 0; i++) {
            unsigned long curr_pfn, last_pfn;

            curr_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
            if (curr_pfn >= max_low_pfn)
                  break;

            last_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;
            if (last_pfn > max_low_pfn)
                  last_pfn = max_low_pfn;

            /*
             * .. finally, did all the rounding and playing
             * around just make the area go away?
             */
            if (last_pfn <= curr_pfn)
                  continue;

            size = (last_pfn - curr_pfn) << PAGE_SHIFT;
            *pages_avail += last_pfn - curr_pfn;

            free_bootmem(sp_banks[i].base_addr, size);
      }

#ifdef CONFIG_BLK_DEV_INITRD
      if (initrd_start) {
            /* Reserve the initrd image area. */
            size = initrd_end - initrd_start;
            reserve_bootmem(initrd_start, size, BOOTMEM_DEFAULT);
            *pages_avail -= PAGE_ALIGN(size) >> PAGE_SHIFT;

            initrd_start = (initrd_start - phys_base) + PAGE_OFFSET;
            initrd_end = (initrd_end - phys_base) + PAGE_OFFSET;        
      }
#endif
      /* Reserve the kernel text/data/bss. */
      size = (start_pfn << PAGE_SHIFT) - phys_base;
      reserve_bootmem(phys_base, size, BOOTMEM_DEFAULT);
      *pages_avail -= PAGE_ALIGN(size) >> PAGE_SHIFT;

      /* Reserve the bootmem map.   We do not account for it
       * in pages_avail because we will release that memory
       * in free_all_bootmem.
       */
      size = bootmap_size;
      reserve_bootmem((bootmap_pfn << PAGE_SHIFT), size, BOOTMEM_DEFAULT);
      *pages_avail -= PAGE_ALIGN(size) >> PAGE_SHIFT;

      return max_pfn;
}

/*
 * check_pgt_cache
 *
 * This is called at the end of unmapping of VMA (zap_page_range),
 * to rescan the page cache for architecture specific things,
 * presumably something like sun4/sun4c PMEGs. Most architectures
 * define check_pgt_cache empty.
 *
 * We simply copy the 2.4 implementation for now.
 */
static int pgt_cache_water[2] = { 25, 50 };

void check_pgt_cache(void)
{
      do_check_pgt_cache(pgt_cache_water[0], pgt_cache_water[1]);
}

/*
 * paging_init() sets up the page tables: We call the MMU specific
 * init routine based upon the Sun model type on the Sparc.
 *
 */
extern void sun4c_paging_init(void);
extern void srmmu_paging_init(void);
extern void device_scan(void);

pgprot_t PAGE_SHARED __read_mostly;
EXPORT_SYMBOL(PAGE_SHARED);

void __init paging_init(void)
{
      switch(sparc_cpu_model) {
      case sun4c:
      case sun4e:
      case sun4:
            sun4c_paging_init();
            sparc_unmapped_base = 0xe0000000;
            BTFIXUPSET_SETHI(sparc_unmapped_base, 0xe0000000);
            break;
      case sun4m:
      case sun4d:
            srmmu_paging_init();
            sparc_unmapped_base = 0x50000000;
            BTFIXUPSET_SETHI(sparc_unmapped_base, 0x50000000);
            break;
      default:
            prom_printf("paging_init: Cannot init paging on this Sparc\n");
            prom_printf("paging_init: sparc_cpu_model = %d\n", sparc_cpu_model);
            prom_printf("paging_init: Halting...\n");
            prom_halt();
      };

      /* Initialize the protection map with non-constant, MMU dependent values. */
      protection_map[0] = PAGE_NONE;
      protection_map[1] = PAGE_READONLY;
      protection_map[2] = PAGE_COPY;
      protection_map[3] = PAGE_COPY;
      protection_map[4] = PAGE_READONLY;
      protection_map[5] = PAGE_READONLY;
      protection_map[6] = PAGE_COPY;
      protection_map[7] = PAGE_COPY;
      protection_map[8] = PAGE_NONE;
      protection_map[9] = PAGE_READONLY;
      protection_map[10] = PAGE_SHARED;
      protection_map[11] = PAGE_SHARED;
      protection_map[12] = PAGE_READONLY;
      protection_map[13] = PAGE_READONLY;
      protection_map[14] = PAGE_SHARED;
      protection_map[15] = PAGE_SHARED;
      btfixup();
      prom_build_devicetree();
      device_scan();
}

static void __init taint_real_pages(void)
{
      int i;

      for (i = 0; sp_banks[i].num_bytes; i++) {
            unsigned long start, end;

            start = sp_banks[i].base_addr;
            end = start + sp_banks[i].num_bytes;

            while (start < end) {
                  set_bit(start >> 20, sparc_valid_addr_bitmap);
                  start += PAGE_SIZE;
            }
      }
}

static void map_high_region(unsigned long start_pfn, unsigned long end_pfn)
{
      unsigned long tmp;

#ifdef CONFIG_DEBUG_HIGHMEM
      printk("mapping high region %08lx - %08lx\n", start_pfn, end_pfn);
#endif

      for (tmp = start_pfn; tmp < end_pfn; tmp++) {
            struct page *page = pfn_to_page(tmp);

            ClearPageReserved(page);
            init_page_count(page);
            __free_page(page);
            totalhigh_pages++;
      }
}

void __init mem_init(void)
{
      int codepages = 0;
      int datapages = 0;
      int initpages = 0; 
      int reservedpages = 0;
      int i;

      if (PKMAP_BASE+LAST_PKMAP*PAGE_SIZE >= FIXADDR_START) {
            prom_printf("BUG: fixmap and pkmap areas overlap\n");
            prom_printf("pkbase: 0x%lx pkend: 0x%lx fixstart 0x%lx\n",
                   PKMAP_BASE,
                   (unsigned long)PKMAP_BASE+LAST_PKMAP*PAGE_SIZE,
                   FIXADDR_START);
            prom_printf("Please mail sparclinux@vger.kernel.org.\n");
            prom_halt();
      }


      /* Saves us work later. */
      memset((void *)&empty_zero_page, 0, PAGE_SIZE);

      i = last_valid_pfn >> ((20 - PAGE_SHIFT) + 5);
      i += 1;
      sparc_valid_addr_bitmap = (unsigned long *)
            __alloc_bootmem(i << 2, SMP_CACHE_BYTES, 0UL);

      if (sparc_valid_addr_bitmap == NULL) {
            prom_printf("mem_init: Cannot alloc valid_addr_bitmap.\n");
            prom_halt();
      }
      memset(sparc_valid_addr_bitmap, 0, i << 2);

      taint_real_pages();

      max_mapnr = last_valid_pfn - pfn_base;
      high_memory = __va(max_low_pfn << PAGE_SHIFT);

      totalram_pages = free_all_bootmem();

      for (i = 0; sp_banks[i].num_bytes != 0; i++) {
            unsigned long start_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
            unsigned long end_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;

            num_physpages += sp_banks[i].num_bytes >> PAGE_SHIFT;

            if (end_pfn <= highstart_pfn)
                  continue;

            if (start_pfn < highstart_pfn)
                  start_pfn = highstart_pfn;

            map_high_region(start_pfn, end_pfn);
      }
      
      totalram_pages += totalhigh_pages;

      codepages = (((unsigned long) &etext) - ((unsigned long)&_start));
      codepages = PAGE_ALIGN(codepages) >> PAGE_SHIFT;
      datapages = (((unsigned long) &edata) - ((unsigned long)&etext));
      datapages = PAGE_ALIGN(datapages) >> PAGE_SHIFT;
      initpages = (((unsigned long) &__init_end) - ((unsigned long) &__init_begin));
      initpages = PAGE_ALIGN(initpages) >> PAGE_SHIFT;

      /* Ignore memory holes for the purpose of counting reserved pages */
      for (i=0; i < max_low_pfn; i++)
            if (test_bit(i >> (20 - PAGE_SHIFT), sparc_valid_addr_bitmap)
                && PageReserved(pfn_to_page(i)))
                  reservedpages++;

      printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, %dk reserved, %dk data, %dk init, %ldk highmem)\n",
             (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
             num_physpages << (PAGE_SHIFT - 10),
             codepages << (PAGE_SHIFT-10),
             reservedpages << (PAGE_SHIFT - 10),
             datapages << (PAGE_SHIFT-10), 
             initpages << (PAGE_SHIFT-10),
             totalhigh_pages << (PAGE_SHIFT-10));
}

void free_initmem (void)
{
      unsigned long addr;

      addr = (unsigned long)(&__init_begin);
      for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
            struct page *p;

            p = virt_to_page(addr);

            ClearPageReserved(p);
            init_page_count(p);
            __free_page(p);
            totalram_pages++;
            num_physpages++;
      }
      printk (KERN_INFO "Freeing unused kernel memory: %dk freed\n", (&__init_end - &__init_begin) >> 10);
}

#ifdef CONFIG_BLK_DEV_INITRD
void free_initrd_mem(unsigned long start, unsigned long end)
{
      if (start < end)
            printk (KERN_INFO "Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
      for (; start < end; start += PAGE_SIZE) {
            struct page *p = virt_to_page(start);

            ClearPageReserved(p);
            init_page_count(p);
            __free_page(p);
            num_physpages++;
      }
}
#endif

void sparc_flush_page_to_ram(struct page *page)
{
      unsigned long vaddr = (unsigned long)page_address(page);

      if (vaddr)
            __flush_page_to_ram(vaddr);
}

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