1 #ifndef _ASM_POWERPC_NOHASH_32_PGTABLE_H
2 #define _ASM_POWERPC_NOHASH_32_PGTABLE_H
3 
4 #include <asm-generic/pgtable-nopmd.h>
5 
6 #ifndef __ASSEMBLY__
7 #include <linux/sched.h>
8 #include <linux/threads.h>
9 #include <asm/io.h>			/* For sub-arch specific PPC_PIN_SIZE */
10 
11 extern unsigned long ioremap_bot;
12 
13 #ifdef CONFIG_44x
14 extern int icache_44x_need_flush;
15 #endif
16 
17 #endif /* __ASSEMBLY__ */
18 
19 #define PTE_INDEX_SIZE	PTE_SHIFT
20 #define PMD_INDEX_SIZE	0
21 #define PUD_INDEX_SIZE	0
22 #define PGD_INDEX_SIZE	(32 - PGDIR_SHIFT)
23 
24 #define PMD_CACHE_INDEX	PMD_INDEX_SIZE
25 
26 #ifndef __ASSEMBLY__
27 #define PTE_TABLE_SIZE	(sizeof(pte_t) << PTE_INDEX_SIZE)
28 #define PMD_TABLE_SIZE	0
29 #define PUD_TABLE_SIZE	0
30 #define PGD_TABLE_SIZE	(sizeof(pgd_t) << PGD_INDEX_SIZE)
31 #endif	/* __ASSEMBLY__ */
32 
33 #define PTRS_PER_PTE	(1 << PTE_INDEX_SIZE)
34 #define PTRS_PER_PGD	(1 << PGD_INDEX_SIZE)
35 
36 /*
37  * The normal case is that PTEs are 32-bits and we have a 1-page
38  * 1024-entry pgdir pointing to 1-page 1024-entry PTE pages.  -- paulus
39  *
40  * For any >32-bit physical address platform, we can use the following
41  * two level page table layout where the pgdir is 8KB and the MS 13 bits
42  * are an index to the second level table.  The combined pgdir/pmd first
43  * level has 2048 entries and the second level has 512 64-bit PTE entries.
44  * -Matt
45  */
46 /* PGDIR_SHIFT determines what a top-level page table entry can map */
47 #define PGDIR_SHIFT	(PAGE_SHIFT + PTE_INDEX_SIZE)
48 #define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
49 #define PGDIR_MASK	(~(PGDIR_SIZE-1))
50 
51 /* Bits to mask out from a PGD to get to the PUD page */
52 #define PGD_MASKED_BITS		0
53 
54 #define USER_PTRS_PER_PGD	(TASK_SIZE / PGDIR_SIZE)
55 #define FIRST_USER_ADDRESS	0UL
56 
57 #define pte_ERROR(e) \
58 	pr_err("%s:%d: bad pte %llx.\n", __FILE__, __LINE__, \
59 		(unsigned long long)pte_val(e))
60 #define pgd_ERROR(e) \
61 	pr_err("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))
62 
63 /*
64  * This is the bottom of the PKMAP area with HIGHMEM or an arbitrary
65  * value (for now) on others, from where we can start layout kernel
66  * virtual space that goes below PKMAP and FIXMAP
67  */
68 #ifdef CONFIG_HIGHMEM
69 #define KVIRT_TOP	PKMAP_BASE
70 #else
71 #define KVIRT_TOP	(0xfe000000UL)	/* for now, could be FIXMAP_BASE ? */
72 #endif
73 
74 /*
75  * ioremap_bot starts at that address. Early ioremaps move down from there,
76  * until mem_init() at which point this becomes the top of the vmalloc
77  * and ioremap space
78  */
79 #ifdef CONFIG_NOT_COHERENT_CACHE
80 #define IOREMAP_TOP	((KVIRT_TOP - CONFIG_CONSISTENT_SIZE) & PAGE_MASK)
81 #else
82 #define IOREMAP_TOP	KVIRT_TOP
83 #endif
84 
85 /*
86  * Just any arbitrary offset to the start of the vmalloc VM area: the
87  * current 16MB value just means that there will be a 64MB "hole" after the
88  * physical memory until the kernel virtual memory starts.  That means that
89  * any out-of-bounds memory accesses will hopefully be caught.
90  * The vmalloc() routines leaves a hole of 4kB between each vmalloced
91  * area for the same reason. ;)
92  *
93  * We no longer map larger than phys RAM with the BATs so we don't have
94  * to worry about the VMALLOC_OFFSET causing problems.  We do have to worry
95  * about clashes between our early calls to ioremap() that start growing down
96  * from IOREMAP_TOP being run into the VM area allocations (growing upwards
97  * from VMALLOC_START).  For this reason we have ioremap_bot to check when
98  * we actually run into our mappings setup in the early boot with the VM
99  * system.  This really does become a problem for machines with good amounts
100  * of RAM.  -- Cort
101  */
102 #define VMALLOC_OFFSET (0x1000000) /* 16M */
103 #ifdef PPC_PIN_SIZE
104 #define VMALLOC_START (((_ALIGN((long)high_memory, PPC_PIN_SIZE) + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1)))
105 #else
106 #define VMALLOC_START ((((long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1)))
107 #endif
108 #define VMALLOC_END	ioremap_bot
109 
110 /*
111  * Bits in a linux-style PTE.  These match the bits in the
112  * (hardware-defined) PowerPC PTE as closely as possible.
113  */
114 
115 #if defined(CONFIG_40x)
116 #include <asm/nohash/32/pte-40x.h>
117 #elif defined(CONFIG_44x)
118 #include <asm/nohash/32/pte-44x.h>
119 #elif defined(CONFIG_FSL_BOOKE) && defined(CONFIG_PTE_64BIT)
120 #include <asm/nohash/pte-book3e.h>
121 #elif defined(CONFIG_FSL_BOOKE)
122 #include <asm/nohash/32/pte-fsl-booke.h>
123 #elif defined(CONFIG_8xx)
124 #include <asm/nohash/32/pte-8xx.h>
125 #endif
126 
127 /* And here we include common definitions */
128 #include <asm/pte-common.h>
129 
130 #ifndef __ASSEMBLY__
131 
132 #define pte_clear(mm, addr, ptep) \
133 	do { pte_update(ptep, ~_PAGE_HASHPTE, 0); } while (0)
134 
135 #define pmd_none(pmd)		(!pmd_val(pmd))
136 #define	pmd_bad(pmd)		(pmd_val(pmd) & _PMD_BAD)
137 #define	pmd_present(pmd)	(pmd_val(pmd) & _PMD_PRESENT_MASK)
138 static inline void pmd_clear(pmd_t *pmdp)
139 {
140 	*pmdp = __pmd(0);
141 }
142 
143 
144 
145 /*
146  * When flushing the tlb entry for a page, we also need to flush the hash
147  * table entry.  flush_hash_pages is assembler (for speed) in hashtable.S.
148  */
149 extern int flush_hash_pages(unsigned context, unsigned long va,
150 			    unsigned long pmdval, int count);
151 
152 /* Add an HPTE to the hash table */
153 extern void add_hash_page(unsigned context, unsigned long va,
154 			  unsigned long pmdval);
155 
156 /* Flush an entry from the TLB/hash table */
157 extern void flush_hash_entry(struct mm_struct *mm, pte_t *ptep,
158 			     unsigned long address);
159 
160 /*
161  * PTE updates. This function is called whenever an existing
162  * valid PTE is updated. This does -not- include set_pte_at()
163  * which nowadays only sets a new PTE.
164  *
165  * Depending on the type of MMU, we may need to use atomic updates
166  * and the PTE may be either 32 or 64 bit wide. In the later case,
167  * when using atomic updates, only the low part of the PTE is
168  * accessed atomically.
169  *
170  * In addition, on 44x, we also maintain a global flag indicating
171  * that an executable user mapping was modified, which is needed
172  * to properly flush the virtually tagged instruction cache of
173  * those implementations.
174  */
175 #ifndef CONFIG_PTE_64BIT
176 static inline unsigned long pte_update(pte_t *p,
177 				       unsigned long clr,
178 				       unsigned long set)
179 {
180 #ifdef PTE_ATOMIC_UPDATES
181 	unsigned long old, tmp;
182 
183 	__asm__ __volatile__("\
184 1:	lwarx	%0,0,%3\n\
185 	andc	%1,%0,%4\n\
186 	or	%1,%1,%5\n"
187 	PPC405_ERR77(0,%3)
188 "	stwcx.	%1,0,%3\n\
189 	bne-	1b"
190 	: "=&r" (old), "=&r" (tmp), "=m" (*p)
191 	: "r" (p), "r" (clr), "r" (set), "m" (*p)
192 	: "cc" );
193 #else /* PTE_ATOMIC_UPDATES */
194 	unsigned long old = pte_val(*p);
195 	*p = __pte((old & ~clr) | set);
196 #endif /* !PTE_ATOMIC_UPDATES */
197 
198 #ifdef CONFIG_44x
199 	if ((old & _PAGE_USER) && (old & _PAGE_EXEC))
200 		icache_44x_need_flush = 1;
201 #endif
202 	return old;
203 }
204 #else /* CONFIG_PTE_64BIT */
205 static inline unsigned long long pte_update(pte_t *p,
206 					    unsigned long clr,
207 					    unsigned long set)
208 {
209 #ifdef PTE_ATOMIC_UPDATES
210 	unsigned long long old;
211 	unsigned long tmp;
212 
213 	__asm__ __volatile__("\
214 1:	lwarx	%L0,0,%4\n\
215 	lwzx	%0,0,%3\n\
216 	andc	%1,%L0,%5\n\
217 	or	%1,%1,%6\n"
218 	PPC405_ERR77(0,%3)
219 "	stwcx.	%1,0,%4\n\
220 	bne-	1b"
221 	: "=&r" (old), "=&r" (tmp), "=m" (*p)
222 	: "r" (p), "r" ((unsigned long)(p) + 4), "r" (clr), "r" (set), "m" (*p)
223 	: "cc" );
224 #else /* PTE_ATOMIC_UPDATES */
225 	unsigned long long old = pte_val(*p);
226 	*p = __pte((old & ~(unsigned long long)clr) | set);
227 #endif /* !PTE_ATOMIC_UPDATES */
228 
229 #ifdef CONFIG_44x
230 	if ((old & _PAGE_USER) && (old & _PAGE_EXEC))
231 		icache_44x_need_flush = 1;
232 #endif
233 	return old;
234 }
235 #endif /* CONFIG_PTE_64BIT */
236 
237 /*
238  * 2.6 calls this without flushing the TLB entry; this is wrong
239  * for our hash-based implementation, we fix that up here.
240  */
241 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
242 static inline int __ptep_test_and_clear_young(unsigned int context, unsigned long addr, pte_t *ptep)
243 {
244 	unsigned long old;
245 	old = pte_update(ptep, _PAGE_ACCESSED, 0);
246 #if _PAGE_HASHPTE != 0
247 	if (old & _PAGE_HASHPTE) {
248 		unsigned long ptephys = __pa(ptep) & PAGE_MASK;
249 		flush_hash_pages(context, addr, ptephys, 1);
250 	}
251 #endif
252 	return (old & _PAGE_ACCESSED) != 0;
253 }
254 #define ptep_test_and_clear_young(__vma, __addr, __ptep) \
255 	__ptep_test_and_clear_young((__vma)->vm_mm->context.id, __addr, __ptep)
256 
257 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
258 static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
259 				       pte_t *ptep)
260 {
261 	return __pte(pte_update(ptep, ~_PAGE_HASHPTE, 0));
262 }
263 
264 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
265 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr,
266 				      pte_t *ptep)
267 {
268 	pte_update(ptep, (_PAGE_RW | _PAGE_HWWRITE), _PAGE_RO);
269 }
270 static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
271 					   unsigned long addr, pte_t *ptep)
272 {
273 	ptep_set_wrprotect(mm, addr, ptep);
274 }
275 
276 
277 static inline void __ptep_set_access_flags(struct mm_struct *mm,
278 					   pte_t *ptep, pte_t entry,
279 					   unsigned long address)
280 {
281 	unsigned long set = pte_val(entry) &
282 		(_PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_RW | _PAGE_EXEC);
283 	unsigned long clr = ~pte_val(entry) & _PAGE_RO;
284 
285 	pte_update(ptep, clr, set);
286 }
287 
288 #define __HAVE_ARCH_PTE_SAME
289 #define pte_same(A,B)	(((pte_val(A) ^ pte_val(B)) & ~_PAGE_HASHPTE) == 0)
290 
291 /*
292  * Note that on Book E processors, the pmd contains the kernel virtual
293  * (lowmem) address of the pte page.  The physical address is less useful
294  * because everything runs with translation enabled (even the TLB miss
295  * handler).  On everything else the pmd contains the physical address
296  * of the pte page.  -- paulus
297  */
298 #ifndef CONFIG_BOOKE
299 #define pmd_page_vaddr(pmd)	\
300 	((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
301 #define pmd_page(pmd)		\
302 	pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT)
303 #else
304 #define pmd_page_vaddr(pmd)	\
305 	((unsigned long) (pmd_val(pmd) & PAGE_MASK))
306 #define pmd_page(pmd)		\
307 	pfn_to_page((__pa(pmd_val(pmd)) >> PAGE_SHIFT))
308 #endif
309 
310 /* to find an entry in a kernel page-table-directory */
311 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
312 
313 /* to find an entry in a page-table-directory */
314 #define pgd_index(address)	 ((address) >> PGDIR_SHIFT)
315 #define pgd_offset(mm, address)	 ((mm)->pgd + pgd_index(address))
316 
317 /* Find an entry in the third-level page table.. */
318 #define pte_index(address)		\
319 	(((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
320 #define pte_offset_kernel(dir, addr)	\
321 	(pmd_bad(*(dir)) ? NULL : (pte_t *)pmd_page_vaddr(*(dir)) + \
322 				  pte_index(addr))
323 #define pte_offset_map(dir, addr)		\
324 	((pte_t *) kmap_atomic(pmd_page(*(dir))) + pte_index(addr))
325 #define pte_unmap(pte)		kunmap_atomic(pte)
326 
327 /*
328  * Encode and decode a swap entry.
329  * Note that the bits we use in a PTE for representing a swap entry
330  * must not include the _PAGE_PRESENT bit or the _PAGE_HASHPTE bit (if used).
331  *   -- paulus
332  */
333 #define __swp_type(entry)		((entry).val & 0x1f)
334 #define __swp_offset(entry)		((entry).val >> 5)
335 #define __swp_entry(type, offset)	((swp_entry_t) { (type) | ((offset) << 5) })
336 #define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) >> 3 })
337 #define __swp_entry_to_pte(x)		((pte_t) { (x).val << 3 })
338 
339 extern int get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep,
340 		      pmd_t **pmdp);
341 
342 #endif /* !__ASSEMBLY__ */
343 
344 #endif /* __ASM_POWERPC_NOHASH_32_PGTABLE_H */
345