arch/csky/mm/highmem.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
   3
   4 #include <linux/module.h>
   5 #include <linux/highmem.h>
   6 #include <linux/smp.h>
   7 #include <linux/memblock.h>
   8 #include <asm/fixmap.h>
   9 #include <asm/tlbflush.h>
  10 #include <asm/cacheflush.h>
  11
  12 static pte_t *kmap_pte;
  13
  14 unsigned long highstart_pfn, highend_pfn;
  15
  16 void kmap_flush_tlb(unsigned long addr)
  17 {
  18         flush_tlb_one(addr);
  19 }
  20 EXPORT_SYMBOL(kmap_flush_tlb);
  21
  22 void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
  23 {
  24         unsigned long vaddr;
  25         int idx, type;
  26
  27         type = kmap_atomic_idx_push();
  28         idx = type + KM_TYPE_NR*smp_processor_id();
  29         vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
  30 #ifdef CONFIG_DEBUG_HIGHMEM
  31         BUG_ON(!pte_none(*(kmap_pte - idx)));
  32 #endif
  33         set_pte(kmap_pte-idx, mk_pte(page, prot));
  34         flush_tlb_one((unsigned long)vaddr);
  35
  36         return (void *)vaddr;
  37 }
  38 EXPORT_SYMBOL(kmap_atomic_high_prot);
  39
  40 void kunmap_atomic_high(void *kvaddr)
  41 {
  42         unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
  43         int idx;
  44
  45         if (vaddr < FIXADDR_START)
  46                 return;
  47
  48 #ifdef CONFIG_DEBUG_HIGHMEM
  49         idx = KM_TYPE_NR*smp_processor_id() + kmap_atomic_idx();
  50
  51         BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
  52
  53         pte_clear(&init_mm, vaddr, kmap_pte - idx);
  54         flush_tlb_one(vaddr);
  55 #else
  56         (void) idx; /* to kill a warning */
  57 #endif
  58         kmap_atomic_idx_pop();
  59 }
  60 EXPORT_SYMBOL(kunmap_atomic_high);
  61
  62 /*
  63  * This is the same as kmap_atomic() but can map memory that doesn't
  64  * have a struct page associated with it.
  65  */
  66 void *kmap_atomic_pfn(unsigned long pfn)
  67 {
  68         unsigned long vaddr;
  69         int idx, type;
  70
  71         pagefault_disable();
  72
  73         type = kmap_atomic_idx_push();
  74         idx = type + KM_TYPE_NR*smp_processor_id();
  75         vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
  76         set_pte(kmap_pte-idx, pfn_pte(pfn, PAGE_KERNEL));
  77         flush_tlb_one(vaddr);
  78
  79         return (void *) vaddr;
  80 }
  81
  82 static void __init kmap_pages_init(void)
  83 {
  84         unsigned long vaddr;
  85         pgd_t *pgd;
  86         pmd_t *pmd;
  87         pud_t *pud;
  88         pte_t *pte;
  89
  90         vaddr = PKMAP_BASE;
  91         fixrange_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, swapper_pg_dir);
  92
  93         pgd = swapper_pg_dir + pgd_index(vaddr);
  94         pud = (pud_t *)pgd;
  95         pmd = pmd_offset(pud, vaddr);
  96         pte = pte_offset_kernel(pmd, vaddr);
  97         pkmap_page_table = pte;
  98 }
  99
 100 void __init kmap_init(void)
 101 {
 102         unsigned long vaddr;
 103
 104         kmap_pages_init();
 105
 106         vaddr = __fix_to_virt(FIX_KMAP_BEGIN);
 107
 108         kmap_pte = pte_offset_kernel((pmd_t *)pgd_offset_k(vaddr), vaddr);
 109 }