pgtable.h

  1/* SPDX-License-Identifier: GPL-2.0 */
  2#ifndef _ASM_POWERPC_NOHASH_PGTABLE_H
  3#define _ASM_POWERPC_NOHASH_PGTABLE_H
  4
  5#ifndef __ASSEMBLER__
  6static inline pte_basic_t pte_update(struct mm_struct *mm, unsigned long addr, pte_t *p,
  7				     unsigned long clr, unsigned long set, int huge);
  8#endif
  9
 10#if defined(CONFIG_PPC64)
 11#include <asm/nohash/64/pgtable.h>
 12#else
 13#include <asm/nohash/32/pgtable.h>
 14#endif
 15
 16/*
 17 * _PAGE_CHG_MASK masks of bits that are to be preserved across
 18 * pgprot changes.
 19 */
 20#define _PAGE_CHG_MASK	(PTE_RPN_MASK | _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_SPECIAL)
 21
 22/* Permission masks used for kernel mappings */
 23#define PAGE_KERNEL	__pgprot(_PAGE_BASE | _PAGE_KERNEL_RW)
 24#define PAGE_KERNEL_NC	__pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | _PAGE_NO_CACHE)
 25#define PAGE_KERNEL_NCG	__pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | _PAGE_NO_CACHE | _PAGE_GUARDED)
 26#define PAGE_KERNEL_X	__pgprot(_PAGE_BASE | _PAGE_KERNEL_RWX)
 27#define PAGE_KERNEL_RO	__pgprot(_PAGE_BASE | _PAGE_KERNEL_RO)
 28#define PAGE_KERNEL_ROX	__pgprot(_PAGE_BASE | _PAGE_KERNEL_ROX)
 29
 30#ifndef __ASSEMBLER__
 31
 32extern int icache_44x_need_flush;
 33
 34#ifndef pte_huge_size
 35static inline unsigned long pte_huge_size(pte_t pte)
 36{
 37	return PAGE_SIZE;
 38}
 39#endif
 40
 41/*
 42 * PTE updates. This function is called whenever an existing
 43 * valid PTE is updated. This does -not- include set_pte_at()
 44 * which nowadays only sets a new PTE.
 45 *
 46 * Depending on the type of MMU, we may need to use atomic updates
 47 * and the PTE may be either 32 or 64 bit wide. In the later case,
 48 * when using atomic updates, only the low part of the PTE is
 49 * accessed atomically.
 50 *
 51 * In addition, on 44x, we also maintain a global flag indicating
 52 * that an executable user mapping was modified, which is needed
 53 * to properly flush the virtually tagged instruction cache of
 54 * those implementations.
 55 */
 56#ifndef pte_update
 57static inline pte_basic_t pte_update(struct mm_struct *mm, unsigned long addr, pte_t *p,
 58				     unsigned long clr, unsigned long set, int huge)
 59{
 60	pte_basic_t old = pte_val(*p);
 61	pte_basic_t new = (old & ~(pte_basic_t)clr) | set;
 62	unsigned long sz;
 63	unsigned long pdsize;
 64	int i;
 65
 66	if (new == old)
 67		return old;
 68
 69	if (huge)
 70		sz = pte_huge_size(__pte(old));
 71	else
 72		sz = PAGE_SIZE;
 73
 74	if (sz < PMD_SIZE)
 75		pdsize = PAGE_SIZE;
 76	else if (sz < PUD_SIZE)
 77		pdsize = PMD_SIZE;
 78	else if (sz < P4D_SIZE)
 79		pdsize = PUD_SIZE;
 80	else if (sz < PGDIR_SIZE)
 81		pdsize = P4D_SIZE;
 82	else
 83		pdsize = PGDIR_SIZE;
 84
 85	for (i = 0; i < sz / pdsize; i++, p++) {
 86		*p = __pte(new);
 87		if (new)
 88			new += (unsigned long long)(pdsize / PAGE_SIZE) << PTE_RPN_SHIFT;
 89	}
 90
 91	if (IS_ENABLED(CONFIG_44x) && !is_kernel_addr(addr) && (old & _PAGE_EXEC))
 92		icache_44x_need_flush = 1;
 93
 94	/* huge pages use the old page table lock */
 95	if (!huge)
 96		assert_pte_locked(mm, addr);
 97
 98	return old;
 99}
100#endif
101
102static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
103					    unsigned long addr, pte_t *ptep)
104{
105	unsigned long old;
106
107	old = pte_update(vma->vm_mm, addr, ptep, _PAGE_ACCESSED, 0, 0);
108
109	return (old & _PAGE_ACCESSED) != 0;
110}
111#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
112
113#ifndef ptep_set_wrprotect
114static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr,
115				      pte_t *ptep)
116{
117	pte_update(mm, addr, ptep, _PAGE_WRITE, 0, 0);
118}
119#endif
120#define __HAVE_ARCH_PTEP_SET_WRPROTECT
121
122static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
123				       pte_t *ptep)
124{
125	return __pte(pte_update(mm, addr, ptep, ~0UL, 0, 0));
126}
127#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
128
129static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
130{
131	pte_update(mm, addr, ptep, ~0UL, 0, 0);
132}
133
134/* Set the dirty and/or accessed bits atomically in a linux PTE */
135#ifndef __ptep_set_access_flags
136static inline void __ptep_set_access_flags(struct vm_area_struct *vma,
137					   pte_t *ptep, pte_t entry,
138					   unsigned long address,
139					   int psize)
140{
141	unsigned long set = pte_val(entry) &
142			    (_PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_RW | _PAGE_EXEC);
143	int huge = psize > mmu_virtual_psize ? 1 : 0;
144
145	pte_update(vma->vm_mm, address, ptep, 0, set, huge);
146
147	flush_tlb_page(vma, address);
148}
149#endif
150
151/* Generic accessors to PTE bits */
152#ifndef pte_mkwrite_novma
153static inline pte_t pte_mkwrite_novma(pte_t pte)
154{
155	/*
156	 * write implies read, hence set both
157	 */
158	return __pte(pte_val(pte) | _PAGE_RW);
159}
160#endif
161
162static inline pte_t pte_mkdirty(pte_t pte)
163{
164	return __pte(pte_val(pte) | _PAGE_DIRTY);
165}
166
167static inline pte_t pte_mkyoung(pte_t pte)
168{
169	return __pte(pte_val(pte) | _PAGE_ACCESSED);
170}
171
172#ifndef pte_wrprotect
173static inline pte_t pte_wrprotect(pte_t pte)
174{
175	return __pte(pte_val(pte) & ~_PAGE_WRITE);
176}
177#endif
178
179#ifndef pte_mkexec
180static inline pte_t pte_mkexec(pte_t pte)
181{
182	return __pte(pte_val(pte) | _PAGE_EXEC);
183}
184#endif
185
186#ifndef pte_write
187static inline int pte_write(pte_t pte)
188{
189	return pte_val(pte) & _PAGE_WRITE;
190}
191#endif
192static inline int pte_dirty(pte_t pte)		{ return pte_val(pte) & _PAGE_DIRTY; }
193static inline int pte_special(pte_t pte)	{ return pte_val(pte) & _PAGE_SPECIAL; }
194static inline int pte_none(pte_t pte)		{ return (pte_val(pte) & ~_PTE_NONE_MASK) == 0; }
195static inline bool pte_hashpte(pte_t pte)	{ return false; }
196static inline bool pte_ci(pte_t pte)		{ return pte_val(pte) & _PAGE_NO_CACHE; }
197static inline bool pte_exec(pte_t pte)		{ return pte_val(pte) & _PAGE_EXEC; }
198
199static inline int pte_present(pte_t pte)
200{
201	return pte_val(pte) & _PAGE_PRESENT;
202}
203
204static inline bool pte_hw_valid(pte_t pte)
205{
206	return pte_val(pte) & _PAGE_PRESENT;
207}
208
209static inline int pte_young(pte_t pte)
210{
211	return pte_val(pte) & _PAGE_ACCESSED;
212}
213
214/*
215 * Don't just check for any non zero bits in __PAGE_READ, since for book3e
216 * and PTE_64BIT, PAGE_KERNEL_X contains _PAGE_BAP_SR which is also in
217 * _PAGE_READ.  Need to explicitly match _PAGE_BAP_UR bit in that case too.
218 */
219#ifndef pte_read
220static inline bool pte_read(pte_t pte)
221{
222	return (pte_val(pte) & _PAGE_READ) == _PAGE_READ;
223}
224#endif
225
226/*
227 * We only find page table entry in the last level
228 * Hence no need for other accessors
229 */
230#define pte_access_permitted pte_access_permitted
231static inline bool pte_access_permitted(pte_t pte, bool write)
232{
233	/*
234	 * A read-only access is controlled by _PAGE_READ bit.
235	 * We have _PAGE_READ set for WRITE
236	 */
237	if (!pte_present(pte) || !pte_read(pte))
238		return false;
239
240	if (write && !pte_write(pte))
241		return false;
242
243	return true;
244}
245
246/* Conversion functions: convert a page and protection to a page entry,
247 * and a page entry and page directory to the page they refer to.
248 *
249 * Even if PTEs can be unsigned long long, a PFN is always an unsigned
250 * long for now.
251 */
252static inline pte_t pfn_pte(unsigned long pfn, pgprot_t pgprot) {
253	return __pte(((pte_basic_t)(pfn) << PTE_RPN_SHIFT) |
254		     pgprot_val(pgprot)); }
255
256/* Generic modifiers for PTE bits */
257static inline pte_t pte_exprotect(pte_t pte)
258{
259	return __pte(pte_val(pte) & ~_PAGE_EXEC);
260}
261
262static inline pte_t pte_mkclean(pte_t pte)
263{
264	return __pte(pte_val(pte) & ~_PAGE_DIRTY);
265}
266
267static inline pte_t pte_mkold(pte_t pte)
268{
269	return __pte(pte_val(pte) & ~_PAGE_ACCESSED);
270}
271
272static inline pte_t pte_mkspecial(pte_t pte)
273{
274	return __pte(pte_val(pte) | _PAGE_SPECIAL);
275}
276
277#ifndef pte_mkhuge
278static inline pte_t pte_mkhuge(pte_t pte)
279{
280	return __pte(pte_val(pte));
281}
282#endif
283
284static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
285{
286	return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot));
287}
288
289static inline bool pte_swp_exclusive(pte_t pte)
290{
291	return pte_val(pte) & _PAGE_SWP_EXCLUSIVE;
292}
293
294static inline pte_t pte_swp_mkexclusive(pte_t pte)
295{
296	return __pte(pte_val(pte) | _PAGE_SWP_EXCLUSIVE);
297}
298
299static inline pte_t pte_swp_clear_exclusive(pte_t pte)
300{
301	return __pte(pte_val(pte) & ~_PAGE_SWP_EXCLUSIVE);
302}
303
304/* This low level function performs the actual PTE insertion
305 * Setting the PTE depends on the MMU type and other factors. It's
306 * an horrible mess that I'm not going to try to clean up now but
307 * I'm keeping it in one place rather than spread around
308 */
309static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr,
310				pte_t *ptep, pte_t pte, int percpu)
311{
312	/* Second case is 32-bit with 64-bit PTE.  In this case, we
313	 * can just store as long as we do the two halves in the right order
314	 * with a barrier in between.
315	 * In the percpu case, we also fallback to the simple update
316	 */
317	if (IS_ENABLED(CONFIG_PPC32) && IS_ENABLED(CONFIG_PTE_64BIT) && !percpu) {
318		__asm__ __volatile__("\
319			stw%X0 %2,%0\n\
320			mbar\n\
321			stw%X1 %L2,%1"
322		: "=m" (*ptep), "=m" (*((unsigned char *)ptep+4))
323		: "r" (pte) : "memory");
324		return;
325	}
326	/* Anything else just stores the PTE normally. That covers all 64-bit
327	 * cases, and 32-bit non-hash with 32-bit PTEs.
328	 */
329#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PPC_16K_PAGES)
330	ptep->pte3 = ptep->pte2 = ptep->pte1 = ptep->pte = pte_val(pte);
331#else
332	*ptep = pte;
333#endif
334
335	/*
336	 * With hardware tablewalk, a sync is needed to ensure that
337	 * subsequent accesses see the PTE we just wrote.  Unlike userspace
338	 * mappings, we can't tolerate spurious faults, so make sure
339	 * the new PTE will be seen the first time.
340	 */
341	if (IS_ENABLED(CONFIG_PPC_BOOK3E_64) && is_kernel_addr(addr))
342		mb();
343}
344
345/*
346 * Macro to mark a page protection value as "uncacheable".
347 */
348
349#define _PAGE_CACHE_CTL	(_PAGE_COHERENT | _PAGE_GUARDED | _PAGE_NO_CACHE | \
350			 _PAGE_WRITETHRU)
351
352#define pgprot_noncached(prot)	  (__pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | \
353				            _PAGE_NO_CACHE | _PAGE_GUARDED))
354
355#define pgprot_noncached_wc(prot) (__pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | \
356				            _PAGE_NO_CACHE))
357
358#define pgprot_cached(prot)       (__pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | \
359				            _PAGE_COHERENT))
360
361#if _PAGE_WRITETHRU != 0
362#define pgprot_cached_wthru(prot) (__pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | \
363				            _PAGE_COHERENT | _PAGE_WRITETHRU))
364#else
365#define pgprot_cached_wthru(prot)	pgprot_noncached(prot)
366#endif
367
368#define pgprot_cached_noncoherent(prot) \
369		(__pgprot(pgprot_val(prot) & ~_PAGE_CACHE_CTL))
370
371#define pgprot_writecombine pgprot_noncached_wc
372
373int map_kernel_page(unsigned long va, phys_addr_t pa, pgprot_t prot);
374void unmap_kernel_page(unsigned long va);
375
376#endif /* __ASSEMBLER__ */
377#endif