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// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
#include <linux/module.h>
#include <linux/highmem.h>
#include <linux/smp.h>
#include <linux/memblock.h>
#include <asm/fixmap.h>
#include <asm/tlbflush.h>
#include <asm/cacheflush.h>
static pte_t *kmap_pte;
unsigned long highstart_pfn, highend_pfn;
void *kmap(struct page *page)
{
void *addr;
might_sleep();
if (!PageHighMem(page))
return page_address(page);
addr = kmap_high(page);
flush_tlb_one((unsigned long)addr);
return addr;
}
EXPORT_SYMBOL(kmap);
void kunmap(struct page *page)
{
BUG_ON(in_interrupt());
if (!PageHighMem(page))
return;
kunmap_high(page);
}
EXPORT_SYMBOL(kunmap);
void *kmap_atomic(struct page *page)
{
unsigned long vaddr;
int idx, type;
preempt_disable();
pagefault_disable();
if (!PageHighMem(page))
return page_address(page);
type = kmap_atomic_idx_push();
idx = type + KM_TYPE_NR*smp_processor_id();
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
#ifdef CONFIG_DEBUG_HIGHMEM
BUG_ON(!pte_none(*(kmap_pte - idx)));
#endif
set_pte(kmap_pte-idx, mk_pte(page, PAGE_KERNEL));
flush_tlb_one((unsigned long)vaddr);
return (void *)vaddr;
}
EXPORT_SYMBOL(kmap_atomic);
void __kunmap_atomic(void *kvaddr)
{
unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
int idx;
if (vaddr < FIXADDR_START)
goto out;
#ifdef CONFIG_DEBUG_HIGHMEM
idx = KM_TYPE_NR*smp_processor_id() + kmap_atomic_idx();
BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
pte_clear(&init_mm, vaddr, kmap_pte - idx);
flush_tlb_one(vaddr);
#else
(void) idx; /* to kill a warning */
#endif
kmap_atomic_idx_pop();
out:
pagefault_enable();
preempt_enable();
}
EXPORT_SYMBOL(__kunmap_atomic);
/*
* This is the same as kmap_atomic() but can map memory that doesn't
* have a struct page associated with it.
*/
void *kmap_atomic_pfn(unsigned long pfn)
{
unsigned long vaddr;
int idx, type;
pagefault_disable();
type = kmap_atomic_idx_push();
idx = type + KM_TYPE_NR*smp_processor_id();
vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
set_pte(kmap_pte-idx, pfn_pte(pfn, PAGE_KERNEL));
flush_tlb_one(vaddr);
return (void *) vaddr;
}
struct page *kmap_atomic_to_page(void *ptr)
{
unsigned long idx, vaddr = (unsigned long)ptr;
pte_t *pte;
if (vaddr < FIXADDR_START)
return virt_to_page(ptr);
idx = virt_to_fix(vaddr);
pte = kmap_pte - (idx - FIX_KMAP_BEGIN);
return pte_page(*pte);
}
static void __init fixrange_init(unsigned long start, unsigned long end,
pgd_t *pgd_base)
{
#ifdef CONFIG_HIGHMEM
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
int i, j, k;
unsigned long vaddr;
vaddr = start;
i = __pgd_offset(vaddr);
j = __pud_offset(vaddr);
k = __pmd_offset(vaddr);
pgd = pgd_base + i;
for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
pud = (pud_t *)pgd;
for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
pmd = (pmd_t *)pud;
for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
if (pmd_none(*pmd)) {
pte = (pte_t *) memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
if (!pte)
panic("%s: Failed to allocate %lu bytes align=%lx\n",
__func__, PAGE_SIZE,
PAGE_SIZE);
set_pmd(pmd, __pmd(__pa(pte)));
BUG_ON(pte != pte_offset_kernel(pmd, 0));
}
vaddr += PMD_SIZE;
}
k = 0;
}
j = 0;
}
#endif
}
void __init fixaddr_kmap_pages_init(void)
{
unsigned long vaddr;
pgd_t *pgd_base;
#ifdef CONFIG_HIGHMEM
pgd_t *pgd;
pmd_t *pmd;
pud_t *pud;
pte_t *pte;
#endif
pgd_base = swapper_pg_dir;
/*
* Fixed mappings:
*/
vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
fixrange_init(vaddr, 0, pgd_base);
#ifdef CONFIG_HIGHMEM
/*
* Permanent kmaps:
*/
vaddr = PKMAP_BASE;
fixrange_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base);
pgd = swapper_pg_dir + __pgd_offset(vaddr);
pud = (pud_t *)pgd;
pmd = pmd_offset(pud, vaddr);
pte = pte_offset_kernel(pmd, vaddr);
pkmap_page_table = pte;
#endif
}
void __init kmap_init(void)
{
unsigned long vaddr;
fixaddr_kmap_pages_init();
vaddr = __fix_to_virt(FIX_KMAP_BEGIN);
kmap_pte = pte_offset_kernel((pmd_t *)pgd_offset_k(vaddr), vaddr);
}
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