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   1 /*
   2  * arch/sh/mm/pg-mmu.c
   3  *
   4  * Copyright (C) 1999, 2000, 2002  Niibe Yutaka
   5  * Copyright (C) 2002 - 2009  Paul Mundt
   6  *
   7  * Released under the terms of the GNU GPL v2.0.
   8  */
   9 #include <linux/mm.h>
  10 #include <linux/init.h>
  11 #include <linux/mutex.h>
  12 #include <linux/fs.h>
  13 #include <linux/highmem.h>
  14 #include <linux/module.h>
  15 #include <asm/mmu_context.h>
  16 #include <asm/cacheflush.h>
  17
  18 #define kmap_get_fixmap_pte(vaddr)                                     \
  19         pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr)), (vaddr))
  20
  21 static pte_t *kmap_coherent_pte;
  22
  23 void __init kmap_coherent_init(void)
  24 {
  25 #if defined(CONFIG_CPU_SH4) || defined(CONFIG_SH7705_CACHE_32KB)
  26         unsigned long vaddr;
  27
  28         /* cache the first coherent kmap pte */
  29         vaddr = __fix_to_virt(FIX_CMAP_BEGIN);
  30         kmap_coherent_pte = kmap_get_fixmap_pte(vaddr);
  31 #endif
  32 }
  33
  34 static void *kmap_coherent(struct page *page, unsigned long addr)
  35 {
  36         enum fixed_addresses idx;
  37         unsigned long vaddr, flags;
  38         pte_t pte;
  39
  40         BUG_ON(test_bit(PG_dcache_dirty, &page->flags));
  41
  42         inc_preempt_count();
  43
  44         idx = (addr & current_cpu_data.dcache.alias_mask) >> PAGE_SHIFT;
  45         vaddr = __fix_to_virt(FIX_CMAP_END - idx);
  46         pte = mk_pte(page, PAGE_KERNEL);
  47
  48         local_irq_save(flags);
  49         flush_tlb_one(get_asid(), vaddr);
  50         local_irq_restore(flags);
  51
  52         update_mmu_cache(NULL, vaddr, pte);
  53
  54         set_pte(kmap_coherent_pte - (FIX_CMAP_END - idx), pte);
  55
  56         return (void *)vaddr;
  57 }
  58
  59 static inline void kunmap_coherent(void)
  60 {
  61         dec_preempt_count();
  62         preempt_check_resched();
  63 }
  64
  65 void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
  66                        unsigned long vaddr, void *dst, const void *src,
  67                        unsigned long len)
  68 {
  69         if (boot_cpu_data.dcache.n_aliases && page_mapped(page) &&
  70             !test_bit(PG_dcache_dirty, &page->flags)) {
  71                 void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
  72                 memcpy(vto, src, len);
  73                 kunmap_coherent();
  74         } else {
  75                 memcpy(dst, src, len);
  76                 if (boot_cpu_data.dcache.n_aliases)
  77                         set_bit(PG_dcache_dirty, &page->flags);
  78         }
  79
  80         if (vma->vm_flags & VM_EXEC)
  81                 flush_cache_page(vma, vaddr, page_to_pfn(page));
  82 }
  83
  84 void copy_from_user_page(struct vm_area_struct *vma, struct page *page,
  85                          unsigned long vaddr, void *dst, const void *src,
  86                          unsigned long len)
  87 {
  88         if (boot_cpu_data.dcache.n_aliases && page_mapped(page) &&
  89             !test_bit(PG_dcache_dirty, &page->flags)) {
  90                 void *vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
  91                 memcpy(dst, vfrom, len);
  92                 kunmap_coherent();
  93         } else {
  94                 memcpy(dst, src, len);
  95                 if (boot_cpu_data.dcache.n_aliases)
  96                         set_bit(PG_dcache_dirty, &page->flags);
  97         }
  98 }
  99
 100 void copy_user_highpage(struct page *to, struct page *from,
 101                         unsigned long vaddr, struct vm_area_struct *vma)
 102 {
 103         void *vfrom, *vto;
 104
 105         vto = kmap_atomic(to, KM_USER1);
 106
 107         if (boot_cpu_data.dcache.n_aliases && page_mapped(from) &&
 108             !test_bit(PG_dcache_dirty, &from->flags)) {
 109                 vfrom = kmap_coherent(from, vaddr);
 110                 copy_page(vto, vfrom);
 111                 kunmap_coherent();
 112         } else {
 113                 vfrom = kmap_atomic(from, KM_USER0);
 114                 copy_page(vto, vfrom);
 115                 kunmap_atomic(vfrom, KM_USER0);
 116         }
 117
 118         if (pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK))
 119                 __flush_wback_region(vto, PAGE_SIZE);
 120
 121         kunmap_atomic(vto, KM_USER1);
 122         /* Make sure this page is cleared on other CPU's too before using it */
 123         smp_wmb();
 124 }
 125 EXPORT_SYMBOL(copy_user_highpage);
 126
 127 void clear_user_highpage(struct page *page, unsigned long vaddr)
 128 {
 129         void *kaddr = kmap_atomic(page, KM_USER0);
 130
 131         clear_page(kaddr);
 132
 133         if (pages_do_alias((unsigned long)kaddr, vaddr & PAGE_MASK))
 134                 __flush_wback_region(kaddr, PAGE_SIZE);
 135
 136         kunmap_atomic(kaddr, KM_USER0);
 137 }
 138 EXPORT_SYMBOL(clear_user_highpage);
 139
 140 void __update_cache(struct vm_area_struct *vma,
 141                     unsigned long address, pte_t pte)
 142 {
 143         struct page *page;
 144         unsigned long pfn = pte_pfn(pte);
 145
 146         if (!boot_cpu_data.dcache.n_aliases)
 147                 return;
 148
 149         page = pfn_to_page(pfn);
 150         if (pfn_valid(pfn) && page_mapping(page)) {
 151                 int dirty = test_and_clear_bit(PG_dcache_dirty, &page->flags);
 152                 if (dirty) {
 153                         unsigned long addr = (unsigned long)page_address(page);
 154
 155                         if (pages_do_alias(addr, address & PAGE_MASK))
 156                                 __flush_wback_region((void *)addr, PAGE_SIZE);
 157                 }
 158         }
 159 }
 160
 161 void __flush_anon_page(struct page *page, unsigned long vmaddr)
 162 {
 163         unsigned long addr = (unsigned long) page_address(page);
 164
 165         if (pages_do_alias(addr, vmaddr)) {
 166                 if (boot_cpu_data.dcache.n_aliases && page_mapped(page) &&
 167                     !test_bit(PG_dcache_dirty, &page->flags)) {
 168                         void *kaddr;
 169
 170                         kaddr = kmap_coherent(page, vmaddr);
 171                         __flush_wback_region((void *)kaddr, PAGE_SIZE);
 172                         kunmap_coherent();
 173                 } else
 174                         __flush_wback_region((void *)addr, PAGE_SIZE);
 175         }
 176 }