LXR linux/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
  12static pte_t *kmap_pte;
  13
  14unsigned long highstart_pfn, highend_pfn;
  15
  16void kmap_flush_tlb(unsigned long addr)
  17{
  18        flush_tlb_one(addr);
  19}
  20EXPORT_SYMBOL(kmap_flush_tlb);
  21
  22void *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}
  38EXPORT_SYMBOL(kmap_atomic_high_prot);
  39
  40void 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}
  60EXPORT_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 */
  66void *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
  82static 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
 100void __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}
 110