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
21 unsigned 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 */
set_pte_vaddr(unsigned long vaddr,pte_t pteval)27 void 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 unsigned long __FIXADDR_TOP = 0xfffff000;
63 EXPORT_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 */
parse_vmalloc(char * arg)70 static 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 }
79 early_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 */
parse_reservetop(char * arg)86 static 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 }
98 early_param("reservetop", parse_reservetop);
99