[PATCH] memory hotplug locking: node_size_lock
[linux-2.6.git] / arch / parisc / mm / ioremap.c
1 /*
2  * arch/parisc/mm/ioremap.c
3  *
4  * Re-map IO memory to kernel address space so that we can access it.
5  * This is needed for high PCI addresses that aren't mapped in the
6  * 640k-1MB IO memory area on PC's
7  *
8  * (C) Copyright 1995 1996 Linus Torvalds
9  * (C) Copyright 2001 Helge Deller <deller@gmx.de>
10  */
11
12 #include <linux/vmalloc.h>
13 #include <linux/errno.h>
14 #include <linux/module.h>
15 #include <asm/io.h>
16 #include <asm/pgalloc.h>
17
18 static inline void remap_area_pte(pte_t * pte, unsigned long address, unsigned long size,
19         unsigned long phys_addr, unsigned long flags)
20 {
21         unsigned long end;
22
23         address &= ~PMD_MASK;
24         end = address + size;
25         if (end > PMD_SIZE)
26                 end = PMD_SIZE;
27         if (address >= end)
28                 BUG();
29         do {
30                 if (!pte_none(*pte)) {
31                         printk(KERN_ERR "remap_area_pte: page already exists\n");
32                         BUG();
33                 }
34                 set_pte(pte, mk_pte_phys(phys_addr, __pgprot(_PAGE_PRESENT | _PAGE_RW | 
35                                         _PAGE_DIRTY | _PAGE_ACCESSED | flags)));
36                 address += PAGE_SIZE;
37                 phys_addr += PAGE_SIZE;
38                 pte++;
39         } while (address && (address < end));
40 }
41
42 static inline int remap_area_pmd(pmd_t * pmd, unsigned long address, unsigned long size,
43         unsigned long phys_addr, unsigned long flags)
44 {
45         unsigned long end;
46
47         address &= ~PGDIR_MASK;
48         end = address + size;
49         if (end > PGDIR_SIZE)
50                 end = PGDIR_SIZE;
51         phys_addr -= address;
52         if (address >= end)
53                 BUG();
54         do {
55                 pte_t * pte = pte_alloc_kernel(pmd, address);
56                 if (!pte)
57                         return -ENOMEM;
58                 remap_area_pte(pte, address, end - address, address + phys_addr, flags);
59                 address = (address + PMD_SIZE) & PMD_MASK;
60                 pmd++;
61         } while (address && (address < end));
62         return 0;
63 }
64
65 #if (USE_HPPA_IOREMAP)
66 static int remap_area_pages(unsigned long address, unsigned long phys_addr,
67                                  unsigned long size, unsigned long flags)
68 {
69         int error;
70         pgd_t * dir;
71         unsigned long end = address + size;
72
73         phys_addr -= address;
74         dir = pgd_offset(&init_mm, address);
75         flush_cache_all();
76         if (address >= end)
77                 BUG();
78         do {
79                 pmd_t *pmd;
80                 pmd = pmd_alloc(&init_mm, dir, address);
81                 error = -ENOMEM;
82                 if (!pmd)
83                         break;
84                 if (remap_area_pmd(pmd, address, end - address,
85                                          phys_addr + address, flags))
86                         break;
87                 error = 0;
88                 address = (address + PGDIR_SIZE) & PGDIR_MASK;
89                 dir++;
90         } while (address && (address < end));
91         flush_tlb_all();
92         return error;
93 }
94 #endif /* USE_HPPA_IOREMAP */
95
96 #ifdef CONFIG_DEBUG_IOREMAP
97 static unsigned long last = 0;
98
99 void gsc_bad_addr(unsigned long addr)
100 {
101         if (time_after(jiffies, last + HZ*10)) {
102                 printk("gsc_foo() called with bad address 0x%lx\n", addr);
103                 dump_stack();
104                 last = jiffies;
105         }
106 }
107 EXPORT_SYMBOL(gsc_bad_addr);
108
109 void __raw_bad_addr(const volatile void __iomem *addr)
110 {
111         if (time_after(jiffies, last + HZ*10)) {
112                 printk("__raw_foo() called with bad address 0x%p\n", addr);
113                 dump_stack();
114                 last = jiffies;
115         }
116 }
117 EXPORT_SYMBOL(__raw_bad_addr);
118 #endif
119
120 /*
121  * Generic mapping function (not visible outside):
122  */
123
124 /*
125  * Remap an arbitrary physical address space into the kernel virtual
126  * address space. Needed when the kernel wants to access high addresses
127  * directly.
128  *
129  * NOTE! We need to allow non-page-aligned mappings too: we will obviously
130  * have to convert them into an offset in a page-aligned mapping, but the
131  * caller shouldn't need to know that small detail.
132  */
133 void __iomem * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags)
134 {
135 #if !(USE_HPPA_IOREMAP)
136
137         unsigned long end = phys_addr + size - 1;
138         /* Support EISA addresses */
139         if ((phys_addr >= 0x00080000 && end < 0x000fffff)
140                         || (phys_addr >= 0x00500000 && end < 0x03bfffff)) {
141                 phys_addr |= 0xfc000000;
142         }
143
144 #ifdef CONFIG_DEBUG_IOREMAP
145         return (void __iomem *)(phys_addr - (0x1UL << NYBBLE_SHIFT));
146 #else
147         return (void __iomem *)phys_addr;
148 #endif
149
150 #else
151         void * addr;
152         struct vm_struct * area;
153         unsigned long offset, last_addr;
154
155         /* Don't allow wraparound or zero size */
156         last_addr = phys_addr + size - 1;
157         if (!size || last_addr < phys_addr)
158                 return NULL;
159
160         /*
161          * Don't allow anybody to remap normal RAM that we're using..
162          */
163         if (phys_addr < virt_to_phys(high_memory)) {
164                 char *t_addr, *t_end;
165                 struct page *page;
166
167                 t_addr = __va(phys_addr);
168                 t_end = t_addr + (size - 1);
169            
170                 for(page = virt_to_page(t_addr); page <= virt_to_page(t_end); page++)
171                         if(!PageReserved(page))
172                                 return NULL;
173         }
174
175         /*
176          * Mappings have to be page-aligned
177          */
178         offset = phys_addr & ~PAGE_MASK;
179         phys_addr &= PAGE_MASK;
180         size = PAGE_ALIGN(last_addr) - phys_addr;
181
182         /*
183          * Ok, go for it..
184          */
185         area = get_vm_area(size, VM_IOREMAP);
186         if (!area)
187                 return NULL;
188         addr = area->addr;
189         if (remap_area_pages((unsigned long) addr, phys_addr, size, flags)) {
190                 vfree(addr);
191                 return NULL;
192         }
193         return (void __iomem *) (offset + (char *)addr);
194 #endif
195 }
196
197 void iounmap(void __iomem *addr)
198 {
199 #if !(USE_HPPA_IOREMAP)
200         return;
201 #else
202         if (addr > high_memory)
203                 return vfree((void *) (PAGE_MASK & (unsigned long __force) addr));
204 #endif
205 }