1#include <linux/sched.h>
2#include <linux/kernel.h>
3#include <linux/errno.h>
4#include <linux/mm.h>
5#include <linux/nmi.h>
6#include <linux/swap.h>
7#include <linux/smp.h>
8#include <linux/highmem.h>
9#include <linux/pagemap.h>
10#include <linux/spinlock.h>
11#include <linux/module.h>
12
13#include <asm/pgtable.h>
14#include <asm/pgalloc.h>
15#include <asm/fixmap.h>
16#include <asm/e820.h>
17#include <asm/tlb.h>
18#include <asm/tlbflush.h>
19#include <asm/io.h>
20
21unsigned int __VMALLOC_RESERVE = 128 << 20;
22
23/*
24 * Associate a virtual page frame with a given physical page frame
25 * and protection flags for that frame.
26 */
27void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
28{
29	pgd_t *pgd;
30	pud_t *pud;
31	pmd_t *pmd;
32	pte_t *pte;
33
34	pgd = swapper_pg_dir + pgd_index(vaddr);
35	if (pgd_none(*pgd)) {
36		BUG();
37		return;
38	}
39	pud = pud_offset(pgd, vaddr);
40	if (pud_none(*pud)) {
41		BUG();
42		return;
43	}
44	pmd = pmd_offset(pud, vaddr);
45	if (pmd_none(*pmd)) {
46		BUG();
47		return;
48	}
49	pte = pte_offset_kernel(pmd, vaddr);
50	if (pte_val(pteval))
51		set_pte_at(&init_mm, vaddr, pte, pteval);
52	else
53		pte_clear(&init_mm, vaddr, pte);
54
55	/*
56	 * It's enough to flush this one mapping.
57	 * (PGE mappings get flushed as well)
58	 */
59	__flush_tlb_one(vaddr);
60}
61
62unsigned long __FIXADDR_TOP = 0xfffff000;
63EXPORT_SYMBOL(__FIXADDR_TOP);
64
65/*
66 * vmalloc=size forces the vmalloc area to be exactly 'size'
67 * bytes. This can be used to increase (or decrease) the
68 * vmalloc area - the default is 128m.
69 */
70static int __init parse_vmalloc(char *arg)
71{
72	if (!arg)
73		return -EINVAL;
74
75	/* Add VMALLOC_OFFSET to the parsed value due to vm area guard hole*/
76	__VMALLOC_RESERVE = memparse(arg, &arg) + VMALLOC_OFFSET;
77	return 0;
78}
79early_param("vmalloc", parse_vmalloc);
80
81/*
82 * reservetop=size reserves a hole at the top of the kernel address space which
83 * a hypervisor can load into later.  Needed for dynamically loaded hypervisors,
84 * so relocating the fixmap can be done before paging initialization.
85 */
86static int __init parse_reservetop(char *arg)
87{
88	unsigned long address;
89
90	if (!arg)
91		return -EINVAL;
92
93	address = memparse(arg, &arg);
94	reserve_top_address(address);
95	early_ioremap_init();
96	return 0;
97}
98early_param("reservetop", parse_reservetop);
99