1/*
2 *  linux/arch/m68k/mm/kmap.c
3 *
4 *  Copyright (C) 1997 Roman Hodek
5 *
6 *  10/01/99 cleaned up the code and changing to the same interface
7 *	     used by other architectures		/Roman Zippel
8 */
9
10#include <linux/module.h>
11#include <linux/mm.h>
12#include <linux/kernel.h>
13#include <linux/string.h>
14#include <linux/types.h>
15#include <linux/slab.h>
16#include <linux/vmalloc.h>
17
18#include <asm/setup.h>
19#include <asm/segment.h>
20#include <asm/page.h>
21#include <asm/pgalloc.h>
22#include <asm/io.h>
23
24#undef DEBUG
25
26#define PTRTREESIZE	(256*1024)
27
28/*
29 * For 040/060 we can use the virtual memory area like other architectures,
30 * but for 020/030 we want to use early termination page descriptors and we
31 * can't mix this with normal page descriptors, so we have to copy that code
32 * (mm/vmalloc.c) and return appropriately aligned addresses.
33 */
34
35#ifdef CPU_M68040_OR_M68060_ONLY
36
37#define IO_SIZE		PAGE_SIZE
38
39static inline struct vm_struct *get_io_area(unsigned long size)
40{
41	return get_vm_area(size, VM_IOREMAP);
42}
43
44
45static inline void free_io_area(void *addr)
46{
47	vfree((void *)(PAGE_MASK & (unsigned long)addr));
48}
49
50#else
51
52#define IO_SIZE		(256*1024)
53
54static struct vm_struct *iolist;
55
56static struct vm_struct *get_io_area(unsigned long size)
57{
58	unsigned long addr;
59	struct vm_struct **p, *tmp, *area;
60
61	area = kmalloc(sizeof(*area), GFP_KERNEL);
62	if (!area)
63		return NULL;
64	addr = KMAP_START;
65	for (p = &iolist; (tmp = *p) ; p = &tmp->next) {
66		if (size + addr < (unsigned long)tmp->addr)
67			break;
68		if (addr > KMAP_END-size) {
69			kfree(area);
70			return NULL;
71		}
72		addr = tmp->size + (unsigned long)tmp->addr;
73	}
74	area->addr = (void *)addr;
75	area->size = size + IO_SIZE;
76	area->next = *p;
77	*p = area;
78	return area;
79}
80
81static inline void free_io_area(void *addr)
82{
83	struct vm_struct **p, *tmp;
84
85	if (!addr)
86		return;
87	addr = (void *)((unsigned long)addr & -IO_SIZE);
88	for (p = &iolist ; (tmp = *p) ; p = &tmp->next) {
89		if (tmp->addr == addr) {
90			*p = tmp->next;
91			__iounmap(tmp->addr, tmp->size);
92			kfree(tmp);
93			return;
94		}
95	}
96}
97
98#endif
99
100/*
101 * Map some physical address range into the kernel address space.
102 */
103/* Rewritten by Andreas Schwab to remove all races. */
104
105void __iomem *__ioremap(unsigned long physaddr, unsigned long size, int cacheflag)
106{
107	struct vm_struct *area;
108	unsigned long virtaddr, retaddr;
109	long offset;
110	pgd_t *pgd_dir;
111	pmd_t *pmd_dir;
112	pte_t *pte_dir;
113
114	/*
115	 * Don't allow mappings that wrap..
116	 */
117	if (!size || physaddr > (unsigned long)(-size))
118		return NULL;
119
120#ifdef CONFIG_AMIGA
121	if (MACH_IS_AMIGA) {
122		if ((physaddr >= 0x40000000) && (physaddr + size < 0x60000000)
123		    && (cacheflag == IOMAP_NOCACHE_SER))
124			return (void __iomem *)physaddr;
125	}
126#endif
127
128#ifdef DEBUG
129	printk("ioremap: 0x%lx,0x%lx(%d) - ", physaddr, size, cacheflag);
130#endif
131	/*
132	 * Mappings have to be aligned
133	 */
134	offset = physaddr & (IO_SIZE - 1);
135	physaddr &= -IO_SIZE;
136	size = (size + offset + IO_SIZE - 1) & -IO_SIZE;
137
138	/*
139	 * Ok, go for it..
140	 */
141	area = get_io_area(size);
142	if (!area)
143		return NULL;
144
145	virtaddr = (unsigned long)area->addr;
146	retaddr = virtaddr + offset;
147#ifdef DEBUG
148	printk("0x%lx,0x%lx,0x%lx", physaddr, virtaddr, retaddr);
149#endif
150
151	/*
152	 * add cache and table flags to physical address
153	 */
154	if (CPU_IS_040_OR_060) {
155		physaddr |= (_PAGE_PRESENT | _PAGE_GLOBAL040 |
156			     _PAGE_ACCESSED | _PAGE_DIRTY);
157		switch (cacheflag) {
158		case IOMAP_FULL_CACHING:
159			physaddr |= _PAGE_CACHE040;
160			break;
161		case IOMAP_NOCACHE_SER:
162		default:
163			physaddr |= _PAGE_NOCACHE_S;
164			break;
165		case IOMAP_NOCACHE_NONSER:
166			physaddr |= _PAGE_NOCACHE;
167			break;
168		case IOMAP_WRITETHROUGH:
169			physaddr |= _PAGE_CACHE040W;
170			break;
171		}
172	} else {
173		physaddr |= (_PAGE_PRESENT | _PAGE_ACCESSED |
174			     _PAGE_DIRTY | _PAGE_READWRITE);
175		switch (cacheflag) {
176		case IOMAP_NOCACHE_SER:
177		case IOMAP_NOCACHE_NONSER:
178		default:
179			physaddr |= _PAGE_NOCACHE030;
180			break;
181		case IOMAP_FULL_CACHING:
182		case IOMAP_WRITETHROUGH:
183			break;
184		}
185	}
186
187	while ((long)size > 0) {
188#ifdef DEBUG
189		if (!(virtaddr & (PTRTREESIZE-1)))
190			printk ("\npa=%#lx va=%#lx ", physaddr, virtaddr);
191#endif
192		pgd_dir = pgd_offset_k(virtaddr);
193		pmd_dir = pmd_alloc(&init_mm, pgd_dir, virtaddr);
194		if (!pmd_dir) {
195			printk("ioremap: no mem for pmd_dir\n");
196			return NULL;
197		}
198
199		if (CPU_IS_020_OR_030) {
200			pmd_dir->pmd[(virtaddr/PTRTREESIZE) & 15] = physaddr;
201			physaddr += PTRTREESIZE;
202			virtaddr += PTRTREESIZE;
203			size -= PTRTREESIZE;
204		} else {
205			pte_dir = pte_alloc_kernel(pmd_dir, virtaddr);
206			if (!pte_dir) {
207				printk("ioremap: no mem for pte_dir\n");
208				return NULL;
209			}
210
211			pte_val(*pte_dir) = physaddr;
212			virtaddr += PAGE_SIZE;
213			physaddr += PAGE_SIZE;
214			size -= PAGE_SIZE;
215		}
216	}
217#ifdef DEBUG
218	printk("\n");
219#endif
220	flush_tlb_all();
221
222	return (void __iomem *)retaddr;
223}
224EXPORT_SYMBOL(__ioremap);
225
226/*
227 * Unmap an ioremap()ed region again
228 */
229void iounmap(void __iomem *addr)
230{
231#ifdef CONFIG_AMIGA
232	if ((!MACH_IS_AMIGA) ||
233	    (((unsigned long)addr < 0x40000000) ||
234	     ((unsigned long)addr > 0x60000000)))
235			free_io_area((__force void *)addr);
236#else
237	free_io_area((__force void *)addr);
238#endif
239}
240EXPORT_SYMBOL(iounmap);
241
242/*
243 * __iounmap unmaps nearly everything, so be careful
244 * Currently it doesn't free pointer/page tables anymore but this
245 * wasn't used anyway and might be added later.
246 */
247void __iounmap(void *addr, unsigned long size)
248{
249	unsigned long virtaddr = (unsigned long)addr;
250	pgd_t *pgd_dir;
251	pmd_t *pmd_dir;
252	pte_t *pte_dir;
253
254	while ((long)size > 0) {
255		pgd_dir = pgd_offset_k(virtaddr);
256		if (pgd_bad(*pgd_dir)) {
257			printk("iounmap: bad pgd(%08lx)\n", pgd_val(*pgd_dir));
258			pgd_clear(pgd_dir);
259			return;
260		}
261		pmd_dir = pmd_offset(pgd_dir, virtaddr);
262
263		if (CPU_IS_020_OR_030) {
264			int pmd_off = (virtaddr/PTRTREESIZE) & 15;
265			int pmd_type = pmd_dir->pmd[pmd_off] & _DESCTYPE_MASK;
266
267			if (pmd_type == _PAGE_PRESENT) {
268				pmd_dir->pmd[pmd_off] = 0;
269				virtaddr += PTRTREESIZE;
270				size -= PTRTREESIZE;
271				continue;
272			} else if (pmd_type == 0)
273				continue;
274		}
275
276		if (pmd_bad(*pmd_dir)) {
277			printk("iounmap: bad pmd (%08lx)\n", pmd_val(*pmd_dir));
278			pmd_clear(pmd_dir);
279			return;
280		}
281		pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
282
283		pte_val(*pte_dir) = 0;
284		virtaddr += PAGE_SIZE;
285		size -= PAGE_SIZE;
286	}
287
288	flush_tlb_all();
289}
290
291/*
292 * Set new cache mode for some kernel address space.
293 * The caller must push data for that range itself, if such data may already
294 * be in the cache.
295 */
296void kernel_set_cachemode(void *addr, unsigned long size, int cmode)
297{
298	unsigned long virtaddr = (unsigned long)addr;
299	pgd_t *pgd_dir;
300	pmd_t *pmd_dir;
301	pte_t *pte_dir;
302
303	if (CPU_IS_040_OR_060) {
304		switch (cmode) {
305		case IOMAP_FULL_CACHING:
306			cmode = _PAGE_CACHE040;
307			break;
308		case IOMAP_NOCACHE_SER:
309		default:
310			cmode = _PAGE_NOCACHE_S;
311			break;
312		case IOMAP_NOCACHE_NONSER:
313			cmode = _PAGE_NOCACHE;
314			break;
315		case IOMAP_WRITETHROUGH:
316			cmode = _PAGE_CACHE040W;
317			break;
318		}
319	} else {
320		switch (cmode) {
321		case IOMAP_NOCACHE_SER:
322		case IOMAP_NOCACHE_NONSER:
323		default:
324			cmode = _PAGE_NOCACHE030;
325			break;
326		case IOMAP_FULL_CACHING:
327		case IOMAP_WRITETHROUGH:
328			cmode = 0;
329		}
330	}
331
332	while ((long)size > 0) {
333		pgd_dir = pgd_offset_k(virtaddr);
334		if (pgd_bad(*pgd_dir)) {
335			printk("iocachemode: bad pgd(%08lx)\n", pgd_val(*pgd_dir));
336			pgd_clear(pgd_dir);
337			return;
338		}
339		pmd_dir = pmd_offset(pgd_dir, virtaddr);
340
341		if (CPU_IS_020_OR_030) {
342			int pmd_off = (virtaddr/PTRTREESIZE) & 15;
343
344			if ((pmd_dir->pmd[pmd_off] & _DESCTYPE_MASK) == _PAGE_PRESENT) {
345				pmd_dir->pmd[pmd_off] = (pmd_dir->pmd[pmd_off] &
346							 _CACHEMASK040) | cmode;
347				virtaddr += PTRTREESIZE;
348				size -= PTRTREESIZE;
349				continue;
350			}
351		}
352
353		if (pmd_bad(*pmd_dir)) {
354			printk("iocachemode: bad pmd (%08lx)\n", pmd_val(*pmd_dir));
355			pmd_clear(pmd_dir);
356			return;
357		}
358		pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
359
360		pte_val(*pte_dir) = (pte_val(*pte_dir) & _CACHEMASK040) | cmode;
361		virtaddr += PAGE_SIZE;
362		size -= PAGE_SIZE;
363	}
364
365	flush_tlb_all();
366}
367EXPORT_SYMBOL(kernel_set_cachemode);
368