linuxdebug/arch/x86/mm/pgtable_32.c

105 lines
2.3 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/nmi.h>
#include <linux/swap.h>
#include <linux/smp.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <linux/spinlock.h>
#include <asm/cpu_entry_area.h>
#include <asm/fixmap.h>
#include <asm/e820/api.h>
#include <asm/tlb.h>
#include <asm/tlbflush.h>
#include <asm/io.h>
#include <linux/vmalloc.h>
unsigned int __VMALLOC_RESERVE = 128 << 20;
/*
* Associate a virtual page frame with a given physical page frame
* and protection flags for that frame.
*/
void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
{
pgd_t *pgd;
p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
pgd = swapper_pg_dir + pgd_index(vaddr);
if (pgd_none(*pgd)) {
BUG();
return;
}
p4d = p4d_offset(pgd, vaddr);
if (p4d_none(*p4d)) {
BUG();
return;
}
pud = pud_offset(p4d, vaddr);
if (pud_none(*pud)) {
BUG();
return;
}
pmd = pmd_offset(pud, vaddr);
if (pmd_none(*pmd)) {
BUG();
return;
}
pte = pte_offset_kernel(pmd, vaddr);
if (!pte_none(pteval))
set_pte_at(&init_mm, vaddr, pte, pteval);
else
pte_clear(&init_mm, vaddr, pte);
/*
* It's enough to flush this one mapping.
* (PGE mappings get flushed as well)
*/
flush_tlb_one_kernel(vaddr);
}
unsigned long __FIXADDR_TOP = 0xfffff000;
EXPORT_SYMBOL(__FIXADDR_TOP);
/*
* vmalloc=size forces the vmalloc area to be exactly 'size'
* bytes. This can be used to increase (or decrease) the
* vmalloc area - the default is 128m.
*/
static int __init parse_vmalloc(char *arg)
{
if (!arg)
return -EINVAL;
/* Add VMALLOC_OFFSET to the parsed value due to vm area guard hole*/
__VMALLOC_RESERVE = memparse(arg, &arg) + VMALLOC_OFFSET;
return 0;
}
early_param("vmalloc", parse_vmalloc);
/*
* reservetop=size reserves a hole at the top of the kernel address space which
* a hypervisor can load into later. Needed for dynamically loaded hypervisors,
* so relocating the fixmap can be done before paging initialization.
*/
static int __init parse_reservetop(char *arg)
{
unsigned long address;
if (!arg)
return -EINVAL;
address = memparse(arg, &arg);
reserve_top_address(address);
early_ioremap_init();
return 0;
}
early_param("reservetop", parse_reservetop);