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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/arch/alpha/mm/init.c
3 *
4 * Copyright (C) 1995 Linus Torvalds
5 */
6
7/* 2.3.x zone allocator, 1999 Andrea Arcangeli <andrea@suse.de> */
8
akpm@osdl.orgdf2e71f2006-01-09 20:51:37 -08009#include <linux/pagemap.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070010#include <linux/signal.h>
11#include <linux/sched.h>
12#include <linux/kernel.h>
13#include <linux/errno.h>
14#include <linux/string.h>
15#include <linux/types.h>
16#include <linux/ptrace.h>
17#include <linux/mman.h>
18#include <linux/mm.h>
19#include <linux/swap.h>
20#include <linux/init.h>
21#include <linux/bootmem.h> /* max_low_pfn */
22#include <linux/vmalloc.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090023#include <linux/gfp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024
Linus Torvalds1da177e2005-04-16 15:20:36 -070025#include <asm/uaccess.h>
26#include <asm/pgtable.h>
27#include <asm/pgalloc.h>
28#include <asm/hwrpb.h>
29#include <asm/dma.h>
30#include <asm/mmu_context.h>
31#include <asm/console.h>
32#include <asm/tlb.h>
David Howellsec221202012-03-28 18:11:12 +010033#include <asm/setup.h>
Jiang Liuf3beeb42013-04-29 15:06:25 -070034#include <asm/sections.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070035
Linus Torvalds1da177e2005-04-16 15:20:36 -070036extern void die_if_kernel(char *,struct pt_regs *,long);
37
38static struct pcb_struct original_pcb;
39
40pgd_t *
41pgd_alloc(struct mm_struct *mm)
42{
43 pgd_t *ret, *init;
44
45 ret = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
46 init = pgd_offset(&init_mm, 0UL);
47 if (ret) {
48#ifdef CONFIG_ALPHA_LARGE_VMALLOC
49 memcpy (ret + USER_PTRS_PER_PGD, init + USER_PTRS_PER_PGD,
50 (PTRS_PER_PGD - USER_PTRS_PER_PGD - 1)*sizeof(pgd_t));
51#else
52 pgd_val(ret[PTRS_PER_PGD-2]) = pgd_val(init[PTRS_PER_PGD-2]);
53#endif
54
55 /* The last PGD entry is the VPTB self-map. */
56 pgd_val(ret[PTRS_PER_PGD-1])
57 = pte_val(mk_pte(virt_to_page(ret), PAGE_KERNEL));
58 }
59 return ret;
60}
61
Linus Torvalds1da177e2005-04-16 15:20:36 -070062
63/*
64 * BAD_PAGE is the page that is used for page faults when linux
65 * is out-of-memory. Older versions of linux just did a
66 * do_exit(), but using this instead means there is less risk
67 * for a process dying in kernel mode, possibly leaving an inode
68 * unused etc..
69 *
70 * BAD_PAGETABLE is the accompanying page-table: it is initialized
71 * to point to BAD_PAGE entries.
72 *
73 * ZERO_PAGE is a special page that is used for zero-initialized
74 * data and COW.
75 */
76pmd_t *
77__bad_pagetable(void)
78{
79 memset((void *) EMPTY_PGT, 0, PAGE_SIZE);
80 return (pmd_t *) EMPTY_PGT;
81}
82
83pte_t
84__bad_page(void)
85{
86 memset((void *) EMPTY_PGE, 0, PAGE_SIZE);
87 return pte_mkdirty(mk_pte(virt_to_page(EMPTY_PGE), PAGE_SHARED));
88}
89
Linus Torvalds1da177e2005-04-16 15:20:36 -070090static inline unsigned long
91load_PCB(struct pcb_struct *pcb)
92{
93 register unsigned long sp __asm__("$30");
94 pcb->ksp = sp;
95 return __reload_thread(pcb);
96}
97
98/* Set up initial PCB, VPTB, and other such nicities. */
99
100static inline void
101switch_to_system_map(void)
102{
103 unsigned long newptbr;
104 unsigned long original_pcb_ptr;
105
106 /* Initialize the kernel's page tables. Linux puts the vptb in
107 the last slot of the L1 page table. */
108 memset(swapper_pg_dir, 0, PAGE_SIZE);
109 newptbr = ((unsigned long) swapper_pg_dir - PAGE_OFFSET) >> PAGE_SHIFT;
110 pgd_val(swapper_pg_dir[1023]) =
111 (newptbr << 32) | pgprot_val(PAGE_KERNEL);
112
113 /* Set the vptb. This is often done by the bootloader, but
114 shouldn't be required. */
115 if (hwrpb->vptb != 0xfffffffe00000000UL) {
116 wrvptptr(0xfffffffe00000000UL);
117 hwrpb->vptb = 0xfffffffe00000000UL;
118 hwrpb_update_checksum(hwrpb);
119 }
120
121 /* Also set up the real kernel PCB while we're at it. */
122 init_thread_info.pcb.ptbr = newptbr;
123 init_thread_info.pcb.flags = 1; /* set FEN, clear everything else */
124 original_pcb_ptr = load_PCB(&init_thread_info.pcb);
125 tbia();
126
127 /* Save off the contents of the original PCB so that we can
128 restore the original console's page tables for a clean reboot.
129
130 Note that the PCB is supposed to be a physical address, but
131 since KSEG values also happen to work, folks get confused.
132 Check this here. */
133
134 if (original_pcb_ptr < PAGE_OFFSET) {
135 original_pcb_ptr = (unsigned long)
136 phys_to_virt(original_pcb_ptr);
137 }
138 original_pcb = *(struct pcb_struct *) original_pcb_ptr;
139}
140
141int callback_init_done;
142
143void * __init
144callback_init(void * kernel_end)
145{
146 struct crb_struct * crb;
147 pgd_t *pgd;
148 pmd_t *pmd;
149 void *two_pages;
150
151 /* Starting at the HWRPB, locate the CRB. */
152 crb = (struct crb_struct *)((char *)hwrpb + hwrpb->crb_offset);
153
154 if (alpha_using_srm) {
155 /* Tell the console whither it is to be remapped. */
156 if (srm_fixup(VMALLOC_START, (unsigned long)hwrpb))
157 __halt(); /* "We're boned." --Bender */
158
159 /* Edit the procedure descriptors for DISPATCH and FIXUP. */
160 crb->dispatch_va = (struct procdesc_struct *)
161 (VMALLOC_START + (unsigned long)crb->dispatch_va
162 - crb->map[0].va);
163 crb->fixup_va = (struct procdesc_struct *)
164 (VMALLOC_START + (unsigned long)crb->fixup_va
165 - crb->map[0].va);
166 }
167
168 switch_to_system_map();
169
170 /* Allocate one PGD and one PMD. In the case of SRM, we'll need
171 these to actually remap the console. There is an assumption
172 here that only one of each is needed, and this allows for 8MB.
173 On systems with larger consoles, additional pages will be
174 allocated as needed during the mapping process.
175
176 In the case of not SRM, but not CONFIG_ALPHA_LARGE_VMALLOC,
177 we need to allocate the PGD we use for vmalloc before we start
178 forking other tasks. */
179
180 two_pages = (void *)
181 (((unsigned long)kernel_end + ~PAGE_MASK) & PAGE_MASK);
182 kernel_end = two_pages + 2*PAGE_SIZE;
183 memset(two_pages, 0, 2*PAGE_SIZE);
184
185 pgd = pgd_offset_k(VMALLOC_START);
186 pgd_set(pgd, (pmd_t *)two_pages);
187 pmd = pmd_offset(pgd, VMALLOC_START);
188 pmd_set(pmd, (pte_t *)(two_pages + PAGE_SIZE));
189
190 if (alpha_using_srm) {
191 static struct vm_struct console_remap_vm;
Tejun Heof0aa6612009-02-20 16:29:08 +0900192 unsigned long nr_pages = 0;
193 unsigned long vaddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 unsigned long i, j;
195
Tejun Heof0aa6612009-02-20 16:29:08 +0900196 /* calculate needed size */
197 for (i = 0; i < crb->map_entries; ++i)
198 nr_pages += crb->map[i].count;
199
200 /* register the vm area */
201 console_remap_vm.flags = VM_ALLOC;
202 console_remap_vm.size = nr_pages << PAGE_SHIFT;
Tejun Heoc0c0a292009-02-24 11:57:21 +0900203 vm_area_register_early(&console_remap_vm, PAGE_SIZE);
Tejun Heof0aa6612009-02-20 16:29:08 +0900204
Tejun Heoaf6326d2009-03-01 16:03:16 +0900205 vaddr = (unsigned long)console_remap_vm.addr;
Tejun Heof0aa6612009-02-20 16:29:08 +0900206
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 /* Set up the third level PTEs and update the virtual
208 addresses of the CRB entries. */
209 for (i = 0; i < crb->map_entries; ++i) {
210 unsigned long pfn = crb->map[i].pa >> PAGE_SHIFT;
211 crb->map[i].va = vaddr;
212 for (j = 0; j < crb->map[i].count; ++j) {
Simon Arlottc3a2dde2007-10-20 01:04:37 +0200213 /* Newer consoles (especially on larger
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214 systems) may require more pages of
215 PTEs. Grab additional pages as needed. */
216 if (pmd != pmd_offset(pgd, vaddr)) {
217 memset(kernel_end, 0, PAGE_SIZE);
218 pmd = pmd_offset(pgd, vaddr);
219 pmd_set(pmd, (pte_t *)kernel_end);
220 kernel_end += PAGE_SIZE;
221 }
222 set_pte(pte_offset_kernel(pmd, vaddr),
223 pfn_pte(pfn, PAGE_KERNEL));
224 pfn++;
225 vaddr += PAGE_SIZE;
226 }
227 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228 }
229
230 callback_init_done = 1;
231 return kernel_end;
232}
233
234
235#ifndef CONFIG_DISCONTIGMEM
236/*
237 * paging_init() sets up the memory map.
238 */
Sam Ravnborg64d158b2007-07-31 00:37:53 -0700239void __init paging_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240{
Christoph Lameterf06a9682006-09-25 23:31:10 -0700241 unsigned long zones_size[MAX_NR_ZONES] = {0, };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242 unsigned long dma_pfn, high_pfn;
243
244 dma_pfn = virt_to_phys((char *)MAX_DMA_ADDRESS) >> PAGE_SHIFT;
245 high_pfn = max_pfn = max_low_pfn;
246
247 if (dma_pfn >= high_pfn)
248 zones_size[ZONE_DMA] = high_pfn;
249 else {
250 zones_size[ZONE_DMA] = dma_pfn;
251 zones_size[ZONE_NORMAL] = high_pfn - dma_pfn;
252 }
253
254 /* Initialize mem_map[]. */
255 free_area_init(zones_size);
256
257 /* Initialize the kernel's ZERO_PGE. */
258 memset((void *)ZERO_PGE, 0, PAGE_SIZE);
259}
260#endif /* CONFIG_DISCONTIGMEM */
261
262#if defined(CONFIG_ALPHA_GENERIC) || defined(CONFIG_ALPHA_SRM)
263void
264srm_paging_stop (void)
265{
266 /* Move the vptb back to where the SRM console expects it. */
267 swapper_pg_dir[1] = swapper_pg_dir[1023];
268 tbia();
269 wrvptptr(0x200000000UL);
270 hwrpb->vptb = 0x200000000UL;
271 hwrpb_update_checksum(hwrpb);
272
273 /* Reload the page tables that the console had in use. */
274 load_PCB(&original_pcb);
275 tbia();
276}
277#endif
278
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279void __init
280mem_init(void)
281{
Jiang Liu2fb1cd52013-07-03 15:04:36 -0700282 set_max_mapnr(max_low_pfn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283 high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
Jiang Liu2fb1cd52013-07-03 15:04:36 -0700284 free_all_bootmem();
Jiang Liud385d9e2013-07-03 15:03:45 -0700285 mem_init_print_info(NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287
288void
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289free_initmem(void)
290{
Jiang Liudbe67df2013-07-03 15:02:51 -0700291 free_initmem_default(-1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292}
293
294#ifdef CONFIG_BLK_DEV_INITRD
295void
296free_initrd_mem(unsigned long start, unsigned long end)
297{
Jiang Liudbe67df2013-07-03 15:02:51 -0700298 free_reserved_area((void *)start, (void *)end, -1, "initrd");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299}
300#endif