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
62/*
63 * Associate a large virtual page frame with a given physical page frame
64 * and protection flags for that frame. pfn is for the base of the page,
65 * vaddr is what the page gets mapped to - both must be properly aligned.
66 * The pmd must already be instantiated. Assumes PAE mode.
67 */
68void set_pmd_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags)
69{
70	pgd_t *pgd;
71	pud_t *pud;
72	pmd_t *pmd;
73
74	if (vaddr & (PMD_SIZE-1)) {		/* vaddr is misaligned */
75		printk(KERN_WARNING "set_pmd_pfn: vaddr misaligned\n");
76		return; /* BUG(); */
77	}
78	if (pfn & (PTRS_PER_PTE-1)) {		/* pfn is misaligned */
79		printk(KERN_WARNING "set_pmd_pfn: pfn misaligned\n");
80		return; /* BUG(); */
81	}
82	pgd = swapper_pg_dir + pgd_index(vaddr);
83	if (pgd_none(*pgd)) {
84		printk(KERN_WARNING "set_pmd_pfn: pgd_none\n");
85		return; /* BUG(); */
86	}
87	pud = pud_offset(pgd, vaddr);
88	pmd = pmd_offset(pud, vaddr);
89	set_pmd(pmd, pfn_pmd(pfn, flags));
90	/*
91	 * It's enough to flush this one mapping.
92	 * (PGE mappings get flushed as well)
93	 */
94	__flush_tlb_one(vaddr);
95}
96
97unsigned long __FIXADDR_TOP = 0xfffff000;
98EXPORT_SYMBOL(__FIXADDR_TOP);
99
100/*
101 * vmalloc=size forces the vmalloc area to be exactly 'size'
102 * bytes. This can be used to increase (or decrease) the
103 * vmalloc area - the default is 128m.
104 */
105static int __init parse_vmalloc(char *arg)
106{
107	if (!arg)
108		return -EINVAL;
109
110	/* Add VMALLOC_OFFSET to the parsed value due to vm area guard hole*/
111	__VMALLOC_RESERVE = memparse(arg, &arg) + VMALLOC_OFFSET;
112	return 0;
113}
114early_param("vmalloc", parse_vmalloc);
115
116/*
117 * reservetop=size reserves a hole at the top of the kernel address space which
118 * a hypervisor can load into later.  Needed for dynamically loaded hypervisors,
119 * so relocating the fixmap can be done before paging initialization.
120 */
121static int __init parse_reservetop(char *arg)
122{
123	unsigned long address;
124
125	if (!arg)
126		return -EINVAL;
127
128	address = memparse(arg, &arg);
129	reserve_top_address(address);
130	fixup_early_ioremap();
131	return 0;
132}
133early_param("reservetop", parse_reservetop);
134