arch/powerpc/mm/mem64.c

   1 /*
   2  *  PowerPC version
   3  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
   4  *
   5  *  Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
   6  *  and Cort Dougan (PReP) (cort@cs.nmt.edu)
   7  *    Copyright (C) 1996 Paul Mackerras
   8  *  Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
   9  *
  10  *  Derived from "arch/i386/mm/init.c"
  11  *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
  12  *
  13  *  Dave Engebretsen <engebret@us.ibm.com>
  14  *      Rework for PPC64 port.
  15  *
  16  *  This program is free software; you can redistribute it and/or
  17  *  modify it under the terms of the GNU General Public License
  18  *  as published by the Free Software Foundation; either version
  19  *  2 of the License, or (at your option) any later version.
  20  *
  21  */
  22
  23 #include <linux/config.h>
  24 #include <linux/signal.h>
  25 #include <linux/sched.h>
  26 #include <linux/kernel.h>
  27 #include <linux/errno.h>
  28 #include <linux/string.h>
  29 #include <linux/types.h>
  30 #include <linux/mman.h>
  31 #include <linux/mm.h>
  32 #include <linux/swap.h>
  33 #include <linux/stddef.h>
  34 #include <linux/vmalloc.h>
  35 #include <linux/init.h>
  36 #include <linux/delay.h>
  37 #include <linux/bootmem.h>
  38 #include <linux/highmem.h>
  39 #include <linux/idr.h>
  40 #include <linux/nodemask.h>
  41 #include <linux/module.h>
  42
  43 #include <asm/pgalloc.h>
  44 #include <asm/page.h>
  45 #include <asm/prom.h>
  46 #include <asm/lmb.h>
  47 #include <asm/rtas.h>
  48 #include <asm/io.h>
  49 #include <asm/mmu_context.h>
  50 #include <asm/pgtable.h>
  51 #include <asm/mmu.h>
  52 #include <asm/uaccess.h>
  53 #include <asm/smp.h>
  54 #include <asm/machdep.h>
  55 #include <asm/tlb.h>
  56 #include <asm/eeh.h>
  57 #include <asm/processor.h>
  58 #include <asm/mmzone.h>
  59 #include <asm/cputable.h>
  60 #include <asm/ppcdebug.h>
  61 #include <asm/sections.h>
  62 #include <asm/system.h>
  63 #include <asm/iommu.h>
  64 #include <asm/abs_addr.h>
  65 #include <asm/vdso.h>
  66 #include <asm/imalloc.h>
  67
  68 /*
  69  * This is called by /dev/mem to know if a given address has to
  70  * be mapped non-cacheable or not
  71  */
  72 int page_is_ram(unsigned long pfn)
  73 {
  74         int i;
  75         unsigned long paddr = (pfn << PAGE_SHIFT);
  76
  77         for (i=0; i < lmb.memory.cnt; i++) {
  78                 unsigned long base;
  79
  80                 base = lmb.memory.region[i].base;
  81
  82                 if ((paddr >= base) &&
  83                         (paddr < (base + lmb.memory.region[i].size))) {
  84                         return 1;
  85                 }
  86         }
  87
  88         return 0;
  89 }
  90 EXPORT_SYMBOL(page_is_ram);
  91
  92 pgprot_t phys_mem_access_prot(struct file *file, unsigned long addr,
  93                               unsigned long size, pgprot_t vma_prot)
  94 {
  95         if (ppc_md.phys_mem_access_prot)
  96                 return ppc_md.phys_mem_access_prot(file, addr, size, vma_prot);
  97
  98         if (!page_is_ram(addr >> PAGE_SHIFT))
  99                 vma_prot = __pgprot(pgprot_val(vma_prot)
 100                                     | _PAGE_GUARDED | _PAGE_NO_CACHE);
 101         return vma_prot;
 102 }
 103 EXPORT_SYMBOL(phys_mem_access_prot);
 104
 105 void show_mem(void)
 106 {
 107         unsigned long total = 0, reserved = 0;
 108         unsigned long shared = 0, cached = 0;
 109         struct page *page;
 110         pg_data_t *pgdat;
 111         unsigned long i;
 112
 113         printk("Mem-info:\n");
 114         show_free_areas();
 115         printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
 116         for_each_pgdat(pgdat) {
 117                 for (i = 0; i < pgdat->node_spanned_pages; i++) {
 118                         page = pgdat_page_nr(pgdat, i);
 119                         total++;
 120                         if (PageReserved(page))
 121                                 reserved++;
 122                         else if (PageSwapCache(page))
 123                                 cached++;
 124                         else if (page_count(page))
 125                                 shared += page_count(page) - 1;
 126                 }
 127         }
 128         printk("%ld pages of RAM\n", total);
 129         printk("%ld reserved pages\n", reserved);
 130         printk("%ld pages shared\n", shared);
 131         printk("%ld pages swap cached\n", cached);
 132 }
 133
 134 /*
 135  * This is called when a page has been modified by the kernel.
 136  * It just marks the page as not i-cache clean.  We do the i-cache
 137  * flush later when the page is given to a user process, if necessary.
 138  */
 139 void flush_dcache_page(struct page *page)
 140 {
 141         if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
 142                 return;
 143         /* avoid an atomic op if possible */
 144         if (test_bit(PG_arch_1, &page->flags))
 145                 clear_bit(PG_arch_1, &page->flags);
 146 }
 147 EXPORT_SYMBOL(flush_dcache_page);
 148
 149 void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
 150 {
 151         clear_page(page);
 152
 153         if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
 154                 return;
 155         /*
 156          * We shouldnt have to do this, but some versions of glibc
 157          * require it (ld.so assumes zero filled pages are icache clean)
 158          * - Anton
 159          */
 160
 161         /* avoid an atomic op if possible */
 162         if (test_bit(PG_arch_1, &pg->flags))
 163                 clear_bit(PG_arch_1, &pg->flags);
 164 }
 165 EXPORT_SYMBOL(clear_user_page);
 166
 167 void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
 168                     struct page *pg)
 169 {
 170         copy_page(vto, vfrom);
 171
 172         /*
 173          * We should be able to use the following optimisation, however
 174          * there are two problems.
 175          * Firstly a bug in some versions of binutils meant PLT sections
 176          * were not marked executable.
 177          * Secondly the first word in the GOT section is blrl, used
 178          * to establish the GOT address. Until recently the GOT was
 179          * not marked executable.
 180          * - Anton
 181          */
 182 #if 0
 183         if (!vma->vm_file && ((vma->vm_flags & VM_EXEC) == 0))
 184                 return;
 185 #endif
 186
 187         if (cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
 188                 return;
 189
 190         /* avoid an atomic op if possible */
 191         if (test_bit(PG_arch_1, &pg->flags))
 192                 clear_bit(PG_arch_1, &pg->flags);
 193 }
 194
 195 void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
 196                              unsigned long addr, int len)
 197 {
 198         unsigned long maddr;
 199
 200         maddr = (unsigned long)page_address(page) + (addr & ~PAGE_MASK);
 201         flush_icache_range(maddr, maddr + len);
 202 }
 203 EXPORT_SYMBOL(flush_icache_user_range);
 204
 205 /*
 206  * This is called at the end of handling a user page fault, when the
 207  * fault has been handled by updating a PTE in the linux page tables.
 208  * We use it to preload an HPTE into the hash table corresponding to
 209  * the updated linux PTE.
 210  *
 211  * This must always be called with the mm->page_table_lock held
 212  */
 213 void update_mmu_cache(struct vm_area_struct *vma, unsigned long ea,
 214                       pte_t pte)
 215 {
 216         unsigned long vsid;
 217         void *pgdir;
 218         pte_t *ptep;
 219         int local = 0;
 220         cpumask_t tmp;
 221         unsigned long flags;
 222
 223         /* handle i-cache coherency */
 224         if (!cpu_has_feature(CPU_FTR_COHERENT_ICACHE) &&
 225             !cpu_has_feature(CPU_FTR_NOEXECUTE)) {
 226                 unsigned long pfn = pte_pfn(pte);
 227                 if (pfn_valid(pfn)) {
 228                         struct page *page = pfn_to_page(pfn);
 229                         if (!PageReserved(page)
 230                             && !test_bit(PG_arch_1, &page->flags)) {
 231                                 __flush_dcache_icache(page_address(page));
 232                                 set_bit(PG_arch_1, &page->flags);
 233                         }
 234                 }
 235         }
 236
 237         /* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
 238         if (!pte_young(pte))
 239                 return;
 240
 241         pgdir = vma->vm_mm->pgd;
 242         if (pgdir == NULL)
 243                 return;
 244
 245         ptep = find_linux_pte(pgdir, ea);
 246         if (!ptep)
 247                 return;
 248
 249         vsid = get_vsid(vma->vm_mm->context.id, ea);
 250
 251         local_irq_save(flags);
 252         tmp = cpumask_of_cpu(smp_processor_id());
 253         if (cpus_equal(vma->vm_mm->cpu_vm_mask, tmp))
 254                 local = 1;
 255
 256         __hash_page(ea, pte_val(pte) & (_PAGE_USER|_PAGE_RW), vsid, ptep,
 257                     0x300, local);
 258         local_irq_restore(flags);
 259 }