1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_POWERPC_BOOK3S_32_PGTABLE_H
3 #define _ASM_POWERPC_BOOK3S_32_PGTABLE_H
4 
5 #define __ARCH_USE_5LEVEL_HACK
6 #include <asm-generic/pgtable-nopmd.h>
7 
8 #include <asm/book3s/32/hash.h>
9 
10 /* And here we include common definitions */
11 #include <asm/pte-common.h>
12 
13 #define PTE_INDEX_SIZE	PTE_SHIFT
14 #define PMD_INDEX_SIZE	0
15 #define PUD_INDEX_SIZE	0
16 #define PGD_INDEX_SIZE	(32 - PGDIR_SHIFT)
17 
18 #define PMD_CACHE_INDEX	PMD_INDEX_SIZE
19 
20 #ifndef __ASSEMBLY__
21 #define PTE_TABLE_SIZE	(sizeof(pte_t) << PTE_INDEX_SIZE)
22 #define PMD_TABLE_SIZE	0
23 #define PUD_TABLE_SIZE	0
24 #define PGD_TABLE_SIZE	(sizeof(pgd_t) << PGD_INDEX_SIZE)
25 #endif	/* __ASSEMBLY__ */
26 
27 #define PTRS_PER_PTE	(1 << PTE_INDEX_SIZE)
28 #define PTRS_PER_PGD	(1 << PGD_INDEX_SIZE)
29 
30 /*
31  * The normal case is that PTEs are 32-bits and we have a 1-page
32  * 1024-entry pgdir pointing to 1-page 1024-entry PTE pages.  -- paulus
33  *
34  * For any >32-bit physical address platform, we can use the following
35  * two level page table layout where the pgdir is 8KB and the MS 13 bits
36  * are an index to the second level table.  The combined pgdir/pmd first
37  * level has 2048 entries and the second level has 512 64-bit PTE entries.
38  * -Matt
39  */
40 /* PGDIR_SHIFT determines what a top-level page table entry can map */
41 #define PGDIR_SHIFT	(PAGE_SHIFT + PTE_INDEX_SIZE)
42 #define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
43 #define PGDIR_MASK	(~(PGDIR_SIZE-1))
44 
45 #define USER_PTRS_PER_PGD	(TASK_SIZE / PGDIR_SIZE)
46 /*
47  * This is the bottom of the PKMAP area with HIGHMEM or an arbitrary
48  * value (for now) on others, from where we can start layout kernel
49  * virtual space that goes below PKMAP and FIXMAP
50  */
51 #ifdef CONFIG_HIGHMEM
52 #define KVIRT_TOP	PKMAP_BASE
53 #else
54 #define KVIRT_TOP	(0xfe000000UL)	/* for now, could be FIXMAP_BASE ? */
55 #endif
56 
57 /*
58  * ioremap_bot starts at that address. Early ioremaps move down from there,
59  * until mem_init() at which point this becomes the top of the vmalloc
60  * and ioremap space
61  */
62 #ifdef CONFIG_NOT_COHERENT_CACHE
63 #define IOREMAP_TOP	((KVIRT_TOP - CONFIG_CONSISTENT_SIZE) & PAGE_MASK)
64 #else
65 #define IOREMAP_TOP	KVIRT_TOP
66 #endif
67 
68 /*
69  * Just any arbitrary offset to the start of the vmalloc VM area: the
70  * current 16MB value just means that there will be a 64MB "hole" after the
71  * physical memory until the kernel virtual memory starts.  That means that
72  * any out-of-bounds memory accesses will hopefully be caught.
73  * The vmalloc() routines leaves a hole of 4kB between each vmalloced
74  * area for the same reason. ;)
75  *
76  * We no longer map larger than phys RAM with the BATs so we don't have
77  * to worry about the VMALLOC_OFFSET causing problems.  We do have to worry
78  * about clashes between our early calls to ioremap() that start growing down
79  * from ioremap_base being run into the VM area allocations (growing upwards
80  * from VMALLOC_START).  For this reason we have ioremap_bot to check when
81  * we actually run into our mappings setup in the early boot with the VM
82  * system.  This really does become a problem for machines with good amounts
83  * of RAM.  -- Cort
84  */
85 #define VMALLOC_OFFSET (0x1000000) /* 16M */
86 #ifdef PPC_PIN_SIZE
87 #define VMALLOC_START (((_ALIGN((long)high_memory, PPC_PIN_SIZE) + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1)))
88 #else
89 #define VMALLOC_START ((((long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1)))
90 #endif
91 #define VMALLOC_END	ioremap_bot
92 
93 #ifndef __ASSEMBLY__
94 #include <linux/sched.h>
95 #include <linux/threads.h>
96 #include <asm/io.h>			/* For sub-arch specific PPC_PIN_SIZE */
97 
98 extern unsigned long ioremap_bot;
99 
100 /* Bits to mask out from a PGD to get to the PUD page */
101 #define PGD_MASKED_BITS		0
102 
103 #define pte_ERROR(e) \
104 	pr_err("%s:%d: bad pte %llx.\n", __FILE__, __LINE__, \
105 		(unsigned long long)pte_val(e))
106 #define pgd_ERROR(e) \
107 	pr_err("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))
108 /*
109  * Bits in a linux-style PTE.  These match the bits in the
110  * (hardware-defined) PowerPC PTE as closely as possible.
111  */
112 
113 #define pte_clear(mm, addr, ptep) \
114 	do { pte_update(ptep, ~_PAGE_HASHPTE, 0); } while (0)
115 
116 #define pmd_none(pmd)		(!pmd_val(pmd))
117 #define	pmd_bad(pmd)		(pmd_val(pmd) & _PMD_BAD)
118 #define	pmd_present(pmd)	(pmd_val(pmd) & _PMD_PRESENT_MASK)
119 static inline void pmd_clear(pmd_t *pmdp)
120 {
121 	*pmdp = __pmd(0);
122 }
123 
124 
125 /*
126  * When flushing the tlb entry for a page, we also need to flush the hash
127  * table entry.  flush_hash_pages is assembler (for speed) in hashtable.S.
128  */
129 extern int flush_hash_pages(unsigned context, unsigned long va,
130 			    unsigned long pmdval, int count);
131 
132 /* Add an HPTE to the hash table */
133 extern void add_hash_page(unsigned context, unsigned long va,
134 			  unsigned long pmdval);
135 
136 /* Flush an entry from the TLB/hash table */
137 extern void flush_hash_entry(struct mm_struct *mm, pte_t *ptep,
138 			     unsigned long address);
139 
140 /*
141  * PTE updates. This function is called whenever an existing
142  * valid PTE is updated. This does -not- include set_pte_at()
143  * which nowadays only sets a new PTE.
144  *
145  * Depending on the type of MMU, we may need to use atomic updates
146  * and the PTE may be either 32 or 64 bit wide. In the later case,
147  * when using atomic updates, only the low part of the PTE is
148  * accessed atomically.
149  *
150  * In addition, on 44x, we also maintain a global flag indicating
151  * that an executable user mapping was modified, which is needed
152  * to properly flush the virtually tagged instruction cache of
153  * those implementations.
154  */
155 #ifndef CONFIG_PTE_64BIT
156 static inline unsigned long pte_update(pte_t *p,
157 				       unsigned long clr,
158 				       unsigned long set)
159 {
160 	unsigned long old, tmp;
161 
162 	__asm__ __volatile__("\
163 1:	lwarx	%0,0,%3\n\
164 	andc	%1,%0,%4\n\
165 	or	%1,%1,%5\n"
166 	PPC405_ERR77(0,%3)
167 "	stwcx.	%1,0,%3\n\
168 	bne-	1b"
169 	: "=&r" (old), "=&r" (tmp), "=m" (*p)
170 	: "r" (p), "r" (clr), "r" (set), "m" (*p)
171 	: "cc" );
172 
173 	return old;
174 }
175 #else /* CONFIG_PTE_64BIT */
176 static inline unsigned long long pte_update(pte_t *p,
177 					    unsigned long clr,
178 					    unsigned long set)
179 {
180 	unsigned long long old;
181 	unsigned long tmp;
182 
183 	__asm__ __volatile__("\
184 1:	lwarx	%L0,0,%4\n\
185 	lwzx	%0,0,%3\n\
186 	andc	%1,%L0,%5\n\
187 	or	%1,%1,%6\n"
188 	PPC405_ERR77(0,%3)
189 "	stwcx.	%1,0,%4\n\
190 	bne-	1b"
191 	: "=&r" (old), "=&r" (tmp), "=m" (*p)
192 	: "r" (p), "r" ((unsigned long)(p) + 4), "r" (clr), "r" (set), "m" (*p)
193 	: "cc" );
194 
195 	return old;
196 }
197 #endif /* CONFIG_PTE_64BIT */
198 
199 /*
200  * 2.6 calls this without flushing the TLB entry; this is wrong
201  * for our hash-based implementation, we fix that up here.
202  */
203 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
204 static inline int __ptep_test_and_clear_young(unsigned int context, unsigned long addr, pte_t *ptep)
205 {
206 	unsigned long old;
207 	old = pte_update(ptep, _PAGE_ACCESSED, 0);
208 	if (old & _PAGE_HASHPTE) {
209 		unsigned long ptephys = __pa(ptep) & PAGE_MASK;
210 		flush_hash_pages(context, addr, ptephys, 1);
211 	}
212 	return (old & _PAGE_ACCESSED) != 0;
213 }
214 #define ptep_test_and_clear_young(__vma, __addr, __ptep) \
215 	__ptep_test_and_clear_young((__vma)->vm_mm->context.id, __addr, __ptep)
216 
217 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
218 static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
219 				       pte_t *ptep)
220 {
221 	return __pte(pte_update(ptep, ~_PAGE_HASHPTE, 0));
222 }
223 
224 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
225 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr,
226 				      pte_t *ptep)
227 {
228 	pte_update(ptep, (_PAGE_RW | _PAGE_HWWRITE), _PAGE_RO);
229 }
230 static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
231 					   unsigned long addr, pte_t *ptep)
232 {
233 	ptep_set_wrprotect(mm, addr, ptep);
234 }
235 
236 
237 static inline void __ptep_set_access_flags(struct mm_struct *mm,
238 					   pte_t *ptep, pte_t entry,
239 					   unsigned long address)
240 {
241 	unsigned long set = pte_val(entry) &
242 		(_PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_RW | _PAGE_EXEC);
243 	unsigned long clr = ~pte_val(entry) & _PAGE_RO;
244 
245 	pte_update(ptep, clr, set);
246 }
247 
248 #define __HAVE_ARCH_PTE_SAME
249 #define pte_same(A,B)	(((pte_val(A) ^ pte_val(B)) & ~_PAGE_HASHPTE) == 0)
250 
251 /*
252  * Note that on Book E processors, the pmd contains the kernel virtual
253  * (lowmem) address of the pte page.  The physical address is less useful
254  * because everything runs with translation enabled (even the TLB miss
255  * handler).  On everything else the pmd contains the physical address
256  * of the pte page.  -- paulus
257  */
258 #ifndef CONFIG_BOOKE
259 #define pmd_page_vaddr(pmd)	\
260 	((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
261 #define pmd_page(pmd)		\
262 	pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT)
263 #else
264 #define pmd_page_vaddr(pmd)	\
265 	((unsigned long) (pmd_val(pmd) & PAGE_MASK))
266 #define pmd_page(pmd)		\
267 	pfn_to_page((__pa(pmd_val(pmd)) >> PAGE_SHIFT))
268 #endif
269 
270 /* to find an entry in a kernel page-table-directory */
271 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
272 
273 /* to find an entry in a page-table-directory */
274 #define pgd_index(address)	 ((address) >> PGDIR_SHIFT)
275 #define pgd_offset(mm, address)	 ((mm)->pgd + pgd_index(address))
276 
277 /* Find an entry in the third-level page table.. */
278 #define pte_index(address)		\
279 	(((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
280 #define pte_offset_kernel(dir, addr)	\
281 	((pte_t *) pmd_page_vaddr(*(dir)) + pte_index(addr))
282 #define pte_offset_map(dir, addr)		\
283 	((pte_t *) kmap_atomic(pmd_page(*(dir))) + pte_index(addr))
284 #define pte_unmap(pte)		kunmap_atomic(pte)
285 
286 /*
287  * Encode and decode a swap entry.
288  * Note that the bits we use in a PTE for representing a swap entry
289  * must not include the _PAGE_PRESENT bit or the _PAGE_HASHPTE bit (if used).
290  *   -- paulus
291  */
292 #define __swp_type(entry)		((entry).val & 0x1f)
293 #define __swp_offset(entry)		((entry).val >> 5)
294 #define __swp_entry(type, offset)	((swp_entry_t) { (type) | ((offset) << 5) })
295 #define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) >> 3 })
296 #define __swp_entry_to_pte(x)		((pte_t) { (x).val << 3 })
297 
298 int map_kernel_page(unsigned long va, phys_addr_t pa, int flags);
299 
300 /* Generic accessors to PTE bits */
301 static inline int pte_write(pte_t pte)		{ return !!(pte_val(pte) & _PAGE_RW);}
302 static inline int pte_read(pte_t pte)		{ return 1; }
303 static inline int pte_dirty(pte_t pte)		{ return !!(pte_val(pte) & _PAGE_DIRTY); }
304 static inline int pte_young(pte_t pte)		{ return !!(pte_val(pte) & _PAGE_ACCESSED); }
305 static inline int pte_special(pte_t pte)	{ return !!(pte_val(pte) & _PAGE_SPECIAL); }
306 static inline int pte_none(pte_t pte)		{ return (pte_val(pte) & ~_PTE_NONE_MASK) == 0; }
307 static inline pgprot_t pte_pgprot(pte_t pte)	{ return __pgprot(pte_val(pte) & PAGE_PROT_BITS); }
308 
309 static inline int pte_present(pte_t pte)
310 {
311 	return pte_val(pte) & _PAGE_PRESENT;
312 }
313 
314 /* Conversion functions: convert a page and protection to a page entry,
315  * and a page entry and page directory to the page they refer to.
316  *
317  * Even if PTEs can be unsigned long long, a PFN is always an unsigned
318  * long for now.
319  */
320 static inline pte_t pfn_pte(unsigned long pfn, pgprot_t pgprot)
321 {
322 	return __pte(((pte_basic_t)(pfn) << PTE_RPN_SHIFT) |
323 		     pgprot_val(pgprot));
324 }
325 
326 static inline unsigned long pte_pfn(pte_t pte)
327 {
328 	return pte_val(pte) >> PTE_RPN_SHIFT;
329 }
330 
331 /* Generic modifiers for PTE bits */
332 static inline pte_t pte_wrprotect(pte_t pte)
333 {
334 	return __pte(pte_val(pte) & ~_PAGE_RW);
335 }
336 
337 static inline pte_t pte_mkclean(pte_t pte)
338 {
339 	return __pte(pte_val(pte) & ~_PAGE_DIRTY);
340 }
341 
342 static inline pte_t pte_mkold(pte_t pte)
343 {
344 	return __pte(pte_val(pte) & ~_PAGE_ACCESSED);
345 }
346 
347 static inline pte_t pte_mkwrite(pte_t pte)
348 {
349 	return __pte(pte_val(pte) | _PAGE_RW);
350 }
351 
352 static inline pte_t pte_mkdirty(pte_t pte)
353 {
354 	return __pte(pte_val(pte) | _PAGE_DIRTY);
355 }
356 
357 static inline pte_t pte_mkyoung(pte_t pte)
358 {
359 	return __pte(pte_val(pte) | _PAGE_ACCESSED);
360 }
361 
362 static inline pte_t pte_mkspecial(pte_t pte)
363 {
364 	return __pte(pte_val(pte) | _PAGE_SPECIAL);
365 }
366 
367 static inline pte_t pte_mkhuge(pte_t pte)
368 {
369 	return pte;
370 }
371 
372 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
373 {
374 	return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot));
375 }
376 
377 
378 
379 /* This low level function performs the actual PTE insertion
380  * Setting the PTE depends on the MMU type and other factors. It's
381  * an horrible mess that I'm not going to try to clean up now but
382  * I'm keeping it in one place rather than spread around
383  */
384 static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr,
385 				pte_t *ptep, pte_t pte, int percpu)
386 {
387 #if defined(CONFIG_PPC_STD_MMU_32) && defined(CONFIG_SMP) && !defined(CONFIG_PTE_64BIT)
388 	/* First case is 32-bit Hash MMU in SMP mode with 32-bit PTEs. We use the
389 	 * helper pte_update() which does an atomic update. We need to do that
390 	 * because a concurrent invalidation can clear _PAGE_HASHPTE. If it's a
391 	 * per-CPU PTE such as a kmap_atomic, we do a simple update preserving
392 	 * the hash bits instead (ie, same as the non-SMP case)
393 	 */
394 	if (percpu)
395 		*ptep = __pte((pte_val(*ptep) & _PAGE_HASHPTE)
396 			      | (pte_val(pte) & ~_PAGE_HASHPTE));
397 	else
398 		pte_update(ptep, ~_PAGE_HASHPTE, pte_val(pte));
399 
400 #elif defined(CONFIG_PPC32) && defined(CONFIG_PTE_64BIT)
401 	/* Second case is 32-bit with 64-bit PTE.  In this case, we
402 	 * can just store as long as we do the two halves in the right order
403 	 * with a barrier in between. This is possible because we take care,
404 	 * in the hash code, to pre-invalidate if the PTE was already hashed,
405 	 * which synchronizes us with any concurrent invalidation.
406 	 * In the percpu case, we also fallback to the simple update preserving
407 	 * the hash bits
408 	 */
409 	if (percpu) {
410 		*ptep = __pte((pte_val(*ptep) & _PAGE_HASHPTE)
411 			      | (pte_val(pte) & ~_PAGE_HASHPTE));
412 		return;
413 	}
414 	if (pte_val(*ptep) & _PAGE_HASHPTE)
415 		flush_hash_entry(mm, ptep, addr);
416 	__asm__ __volatile__("\
417 		stw%U0%X0 %2,%0\n\
418 		eieio\n\
419 		stw%U0%X0 %L2,%1"
420 	: "=m" (*ptep), "=m" (*((unsigned char *)ptep+4))
421 	: "r" (pte) : "memory");
422 
423 #elif defined(CONFIG_PPC_STD_MMU_32)
424 	/* Third case is 32-bit hash table in UP mode, we need to preserve
425 	 * the _PAGE_HASHPTE bit since we may not have invalidated the previous
426 	 * translation in the hash yet (done in a subsequent flush_tlb_xxx())
427 	 * and see we need to keep track that this PTE needs invalidating
428 	 */
429 	*ptep = __pte((pte_val(*ptep) & _PAGE_HASHPTE)
430 		      | (pte_val(pte) & ~_PAGE_HASHPTE));
431 
432 #else
433 #error "Not supported "
434 #endif
435 }
436 
437 /*
438  * Macro to mark a page protection value as "uncacheable".
439  */
440 
441 #define _PAGE_CACHE_CTL	(_PAGE_COHERENT | _PAGE_GUARDED | _PAGE_NO_CACHE | \
442 			 _PAGE_WRITETHRU)
443 
444 #define pgprot_noncached pgprot_noncached
445 static inline pgprot_t pgprot_noncached(pgprot_t prot)
446 {
447 	return __pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) |
448 			_PAGE_NO_CACHE | _PAGE_GUARDED);
449 }
450 
451 #define pgprot_noncached_wc pgprot_noncached_wc
452 static inline pgprot_t pgprot_noncached_wc(pgprot_t prot)
453 {
454 	return __pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) |
455 			_PAGE_NO_CACHE);
456 }
457 
458 #define pgprot_cached pgprot_cached
459 static inline pgprot_t pgprot_cached(pgprot_t prot)
460 {
461 	return __pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) |
462 			_PAGE_COHERENT);
463 }
464 
465 #define pgprot_cached_wthru pgprot_cached_wthru
466 static inline pgprot_t pgprot_cached_wthru(pgprot_t prot)
467 {
468 	return __pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) |
469 			_PAGE_COHERENT | _PAGE_WRITETHRU);
470 }
471 
472 #define pgprot_cached_noncoherent pgprot_cached_noncoherent
473 static inline pgprot_t pgprot_cached_noncoherent(pgprot_t prot)
474 {
475 	return __pgprot(pgprot_val(prot) & ~_PAGE_CACHE_CTL);
476 }
477 
478 #define pgprot_writecombine pgprot_writecombine
479 static inline pgprot_t pgprot_writecombine(pgprot_t prot)
480 {
481 	return pgprot_noncached_wc(prot);
482 }
483 
484 #endif /* !__ASSEMBLY__ */
485 
486 #endif /*  _ASM_POWERPC_BOOK3S_32_PGTABLE_H */
487