]>
Commit | Line | Data |
---|---|---|
15902bf6 MS |
1 | /* |
2 | * This file contains the routines setting up the linux page tables. | |
3 | * | |
4 | * Copyright (C) 2008 Michal Simek | |
5 | * Copyright (C) 2008 PetaLogix | |
6 | * | |
7 | * Copyright (C) 2007 Xilinx, Inc. All rights reserved. | |
8 | * | |
9 | * Derived from arch/ppc/mm/pgtable.c: | |
10 | * -- paulus | |
11 | * | |
12 | * Derived from arch/ppc/mm/init.c: | |
13 | * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) | |
14 | * | |
15 | * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au) | |
16 | * and Cort Dougan (PReP) (cort@cs.nmt.edu) | |
17 | * Copyright (C) 1996 Paul Mackerras | |
18 | * Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk). | |
19 | * | |
20 | * Derived from "arch/i386/mm/init.c" | |
21 | * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds | |
22 | * | |
23 | * This file is subject to the terms and conditions of the GNU General | |
24 | * Public License. See the file COPYING in the main directory of this | |
25 | * archive for more details. | |
26 | * | |
27 | */ | |
28 | ||
29 | #include <linux/kernel.h> | |
30 | #include <linux/module.h> | |
31 | #include <linux/types.h> | |
32 | #include <linux/vmalloc.h> | |
33 | #include <linux/init.h> | |
34 | ||
35 | #include <asm/pgtable.h> | |
36 | #include <asm/pgalloc.h> | |
37 | #include <linux/io.h> | |
38 | #include <asm/mmu.h> | |
39 | #include <asm/sections.h> | |
40 | ||
41 | #define flush_HPTE(X, va, pg) _tlbie(va) | |
42 | ||
43 | unsigned long ioremap_base; | |
44 | unsigned long ioremap_bot; | |
45 | ||
46 | /* The maximum lowmem defaults to 768Mb, but this can be configured to | |
47 | * another value. | |
48 | */ | |
49 | #define MAX_LOW_MEM CONFIG_LOWMEM_SIZE | |
50 | ||
51 | #ifndef CONFIG_SMP | |
52 | struct pgtable_cache_struct quicklists; | |
53 | #endif | |
54 | ||
55 | static void __iomem *__ioremap(phys_addr_t addr, unsigned long size, | |
56 | unsigned long flags) | |
57 | { | |
58 | unsigned long v, i; | |
59 | phys_addr_t p; | |
60 | int err; | |
61 | ||
62 | /* | |
63 | * Choose an address to map it to. | |
64 | * Once the vmalloc system is running, we use it. | |
65 | * Before then, we use space going down from ioremap_base | |
66 | * (ioremap_bot records where we're up to). | |
67 | */ | |
68 | p = addr & PAGE_MASK; | |
69 | size = PAGE_ALIGN(addr + size) - p; | |
70 | ||
71 | /* | |
72 | * Don't allow anybody to remap normal RAM that we're using. | |
73 | * mem_init() sets high_memory so only do the check after that. | |
74 | * | |
75 | * However, allow remap of rootfs: TBD | |
76 | */ | |
77 | if (mem_init_done && | |
78 | p >= memory_start && p < virt_to_phys(high_memory) && | |
79 | !(p >= virt_to_phys((unsigned long)&__bss_stop) && | |
80 | p < virt_to_phys((unsigned long)__bss_stop))) { | |
81 | printk(KERN_WARNING "__ioremap(): phys addr "PTE_FMT | |
82 | " is RAM lr %p\n", (unsigned long)p, | |
83 | __builtin_return_address(0)); | |
84 | return NULL; | |
85 | } | |
86 | ||
87 | if (size == 0) | |
88 | return NULL; | |
89 | ||
90 | /* | |
91 | * Is it already mapped? If the whole area is mapped then we're | |
92 | * done, otherwise remap it since we want to keep the virt addrs for | |
93 | * each request contiguous. | |
94 | * | |
95 | * We make the assumption here that if the bottom and top | |
96 | * of the range we want are mapped then it's mapped to the | |
97 | * same virt address (and this is contiguous). | |
98 | * -- Cort | |
99 | */ | |
100 | ||
101 | if (mem_init_done) { | |
102 | struct vm_struct *area; | |
103 | area = get_vm_area(size, VM_IOREMAP); | |
104 | if (area == NULL) | |
105 | return NULL; | |
cca5613f | 106 | v = (unsigned long) area->addr; |
15902bf6 MS |
107 | } else { |
108 | v = (ioremap_bot -= size); | |
109 | } | |
110 | ||
111 | if ((flags & _PAGE_PRESENT) == 0) | |
112 | flags |= _PAGE_KERNEL; | |
113 | if (flags & _PAGE_NO_CACHE) | |
114 | flags |= _PAGE_GUARDED; | |
115 | ||
116 | err = 0; | |
117 | for (i = 0; i < size && err == 0; i += PAGE_SIZE) | |
118 | err = map_page(v + i, p + i, flags); | |
119 | if (err) { | |
120 | if (mem_init_done) | |
121 | vfree((void *)v); | |
122 | return NULL; | |
123 | } | |
124 | ||
125 | return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK)); | |
126 | } | |
127 | ||
128 | void __iomem *ioremap(phys_addr_t addr, unsigned long size) | |
129 | { | |
130 | return __ioremap(addr, size, _PAGE_NO_CACHE); | |
131 | } | |
132 | EXPORT_SYMBOL(ioremap); | |
133 | ||
134 | void iounmap(void *addr) | |
135 | { | |
136 | if (addr > high_memory && (unsigned long) addr < ioremap_bot) | |
137 | vfree((void *) (PAGE_MASK & (unsigned long) addr)); | |
138 | } | |
139 | EXPORT_SYMBOL(iounmap); | |
140 | ||
141 | ||
142 | int map_page(unsigned long va, phys_addr_t pa, int flags) | |
143 | { | |
144 | pmd_t *pd; | |
145 | pte_t *pg; | |
146 | int err = -ENOMEM; | |
15902bf6 MS |
147 | /* Use upper 10 bits of VA to index the first level map */ |
148 | pd = pmd_offset(pgd_offset_k(va), va); | |
149 | /* Use middle 10 bits of VA to index the second-level map */ | |
150 | pg = pte_alloc_kernel(pd, va); /* from powerpc - pgtable.c */ | |
151 | /* pg = pte_alloc_kernel(&init_mm, pd, va); */ | |
152 | ||
153 | if (pg != NULL) { | |
154 | err = 0; | |
155 | set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, | |
156 | __pgprot(flags))); | |
78ebfa88 | 157 | if (unlikely(mem_init_done)) |
15902bf6 MS |
158 | flush_HPTE(0, va, pmd_val(*pd)); |
159 | /* flush_HPTE(0, va, pg); */ | |
15902bf6 | 160 | } |
15902bf6 MS |
161 | return err; |
162 | } | |
163 | ||
164 | void __init adjust_total_lowmem(void) | |
165 | { | |
166 | /* TBD */ | |
167 | #if 0 | |
168 | unsigned long max_low_mem = MAX_LOW_MEM; | |
169 | ||
170 | if (total_lowmem > max_low_mem) { | |
171 | total_lowmem = max_low_mem; | |
172 | #ifndef CONFIG_HIGHMEM | |
173 | printk(KERN_INFO "Warning, memory limited to %ld Mb, use " | |
174 | "CONFIG_HIGHMEM to reach %ld Mb\n", | |
175 | max_low_mem >> 20, total_memory >> 20); | |
176 | total_memory = total_lowmem; | |
177 | #endif /* CONFIG_HIGHMEM */ | |
178 | } | |
179 | #endif | |
180 | } | |
181 | ||
15902bf6 MS |
182 | /* |
183 | * Map in all of physical memory starting at CONFIG_KERNEL_START. | |
184 | */ | |
185 | void __init mapin_ram(void) | |
186 | { | |
187 | unsigned long v, p, s, f; | |
188 | ||
189 | v = CONFIG_KERNEL_START; | |
190 | p = memory_start; | |
15902bf6 MS |
191 | for (s = 0; s < memory_size; s += PAGE_SIZE) { |
192 | f = _PAGE_PRESENT | _PAGE_ACCESSED | | |
193 | _PAGE_SHARED | _PAGE_HWEXEC; | |
194 | if ((char *) v < _stext || (char *) v >= _etext) | |
195 | f |= _PAGE_WRENABLE; | |
196 | else | |
197 | /* On the MicroBlaze, no user access | |
198 | forces R/W kernel access */ | |
199 | f |= _PAGE_USER; | |
200 | map_page(v, p, f); | |
201 | v += PAGE_SIZE; | |
202 | p += PAGE_SIZE; | |
203 | } | |
204 | } | |
205 | ||
206 | /* is x a power of 2? */ | |
207 | #define is_power_of_2(x) ((x) != 0 && (((x) & ((x) - 1)) == 0)) | |
208 | ||
209 | /* | |
210 | * Set up a mapping for a block of I/O. | |
211 | * virt, phys, size must all be page-aligned. | |
212 | * This should only be called before ioremap is called. | |
213 | */ | |
214 | void __init io_block_mapping(unsigned long virt, phys_addr_t phys, | |
215 | unsigned int size, int flags) | |
216 | { | |
217 | int i; | |
218 | ||
219 | if (virt > CONFIG_KERNEL_START && virt < ioremap_bot) | |
220 | ioremap_bot = ioremap_base = virt; | |
221 | ||
222 | /* Put it in the page tables. */ | |
223 | for (i = 0; i < size; i += PAGE_SIZE) | |
224 | map_page(virt + i, phys + i, flags); | |
225 | } | |
226 | ||
227 | /* Scan the real Linux page tables and return a PTE pointer for | |
228 | * a virtual address in a context. | |
229 | * Returns true (1) if PTE was found, zero otherwise. The pointer to | |
230 | * the PTE pointer is unmodified if PTE is not found. | |
231 | */ | |
232 | static int get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep) | |
233 | { | |
234 | pgd_t *pgd; | |
235 | pmd_t *pmd; | |
236 | pte_t *pte; | |
237 | int retval = 0; | |
238 | ||
239 | pgd = pgd_offset(mm, addr & PAGE_MASK); | |
240 | if (pgd) { | |
241 | pmd = pmd_offset(pgd, addr & PAGE_MASK); | |
242 | if (pmd_present(*pmd)) { | |
243 | pte = pte_offset_kernel(pmd, addr & PAGE_MASK); | |
244 | if (pte) { | |
245 | retval = 1; | |
246 | *ptep = pte; | |
247 | } | |
248 | } | |
249 | } | |
250 | return retval; | |
251 | } | |
252 | ||
253 | /* Find physical address for this virtual address. Normally used by | |
254 | * I/O functions, but anyone can call it. | |
255 | */ | |
256 | unsigned long iopa(unsigned long addr) | |
257 | { | |
258 | unsigned long pa; | |
259 | ||
260 | pte_t *pte; | |
261 | struct mm_struct *mm; | |
262 | ||
263 | /* Allow mapping of user addresses (within the thread) | |
264 | * for DMA if necessary. | |
265 | */ | |
266 | if (addr < TASK_SIZE) | |
267 | mm = current->mm; | |
268 | else | |
269 | mm = &init_mm; | |
270 | ||
271 | pa = 0; | |
272 | if (get_pteptr(mm, addr, &pte)) | |
273 | pa = (pte_val(*pte) & PAGE_MASK) | (addr & ~PAGE_MASK); | |
274 | ||
275 | return pa; | |
276 | } |