1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_POWERPC_NOHASH_PGTABLE_H
3 #define _ASM_POWERPC_NOHASH_PGTABLE_H
4 
5 #if defined(CONFIG_PPC64)
6 #include <asm/nohash/64/pgtable.h>
7 #else
8 #include <asm/nohash/32/pgtable.h>
9 #endif
10 
11 /* Permission masks used for kernel mappings */
12 #define PAGE_KERNEL	__pgprot(_PAGE_BASE | _PAGE_KERNEL_RW)
13 #define PAGE_KERNEL_NC	__pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | _PAGE_NO_CACHE)
14 #define PAGE_KERNEL_NCG	__pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | _PAGE_NO_CACHE | _PAGE_GUARDED)
15 #define PAGE_KERNEL_X	__pgprot(_PAGE_BASE | _PAGE_KERNEL_RWX)
16 #define PAGE_KERNEL_RO	__pgprot(_PAGE_BASE | _PAGE_KERNEL_RO)
17 #define PAGE_KERNEL_ROX	__pgprot(_PAGE_BASE | _PAGE_KERNEL_ROX)
18 
19 #ifndef __ASSEMBLY__
20 
21 /* Generic accessors to PTE bits */
22 #ifndef pte_write
23 static inline int pte_write(pte_t pte)
24 {
25 	return pte_val(pte) & _PAGE_RW;
26 }
27 #endif
28 static inline int pte_read(pte_t pte)		{ return 1; }
29 static inline int pte_dirty(pte_t pte)		{ return pte_val(pte) & _PAGE_DIRTY; }
30 static inline int pte_special(pte_t pte)	{ return pte_val(pte) & _PAGE_SPECIAL; }
31 static inline int pte_none(pte_t pte)		{ return (pte_val(pte) & ~_PTE_NONE_MASK) == 0; }
32 static inline bool pte_hashpte(pte_t pte)	{ return false; }
33 static inline bool pte_ci(pte_t pte)		{ return pte_val(pte) & _PAGE_NO_CACHE; }
34 static inline bool pte_exec(pte_t pte)		{ return pte_val(pte) & _PAGE_EXEC; }
35 
36 #ifdef CONFIG_NUMA_BALANCING
37 /*
38  * These work without NUMA balancing but the kernel does not care. See the
39  * comment in include/linux/pgtable.h . On powerpc, this will only
40  * work for user pages and always return true for kernel pages.
41  */
42 static inline int pte_protnone(pte_t pte)
43 {
44 	return pte_present(pte) && !pte_user(pte);
45 }
46 
47 static inline int pmd_protnone(pmd_t pmd)
48 {
49 	return pte_protnone(pmd_pte(pmd));
50 }
51 #endif /* CONFIG_NUMA_BALANCING */
52 
53 static inline int pte_present(pte_t pte)
54 {
55 	return pte_val(pte) & _PAGE_PRESENT;
56 }
57 
58 static inline bool pte_hw_valid(pte_t pte)
59 {
60 	return pte_val(pte) & _PAGE_PRESENT;
61 }
62 
63 /*
64  * Don't just check for any non zero bits in __PAGE_USER, since for book3e
65  * and PTE_64BIT, PAGE_KERNEL_X contains _PAGE_BAP_SR which is also in
66  * _PAGE_USER.  Need to explicitly match _PAGE_BAP_UR bit in that case too.
67  */
68 #ifndef pte_user
69 static inline bool pte_user(pte_t pte)
70 {
71 	return (pte_val(pte) & _PAGE_USER) == _PAGE_USER;
72 }
73 #endif
74 
75 /*
76  * We only find page table entry in the last level
77  * Hence no need for other accessors
78  */
79 #define pte_access_permitted pte_access_permitted
80 static inline bool pte_access_permitted(pte_t pte, bool write)
81 {
82 	/*
83 	 * A read-only access is controlled by _PAGE_USER bit.
84 	 * We have _PAGE_READ set for WRITE and EXECUTE
85 	 */
86 	if (!pte_present(pte) || !pte_user(pte) || !pte_read(pte))
87 		return false;
88 
89 	if (write && !pte_write(pte))
90 		return false;
91 
92 	return true;
93 }
94 
95 /* Conversion functions: convert a page and protection to a page entry,
96  * and a page entry and page directory to the page they refer to.
97  *
98  * Even if PTEs can be unsigned long long, a PFN is always an unsigned
99  * long for now.
100  */
101 static inline pte_t pfn_pte(unsigned long pfn, pgprot_t pgprot) {
102 	return __pte(((pte_basic_t)(pfn) << PTE_RPN_SHIFT) |
103 		     pgprot_val(pgprot)); }
104 
105 /* Generic modifiers for PTE bits */
106 static inline pte_t pte_exprotect(pte_t pte)
107 {
108 	return __pte(pte_val(pte) & ~_PAGE_EXEC);
109 }
110 
111 static inline pte_t pte_mkclean(pte_t pte)
112 {
113 	return __pte(pte_val(pte) & ~_PAGE_DIRTY);
114 }
115 
116 static inline pte_t pte_mkold(pte_t pte)
117 {
118 	return __pte(pte_val(pte) & ~_PAGE_ACCESSED);
119 }
120 
121 static inline pte_t pte_mkspecial(pte_t pte)
122 {
123 	return __pte(pte_val(pte) | _PAGE_SPECIAL);
124 }
125 
126 #ifndef pte_mkhuge
127 static inline pte_t pte_mkhuge(pte_t pte)
128 {
129 	return __pte(pte_val(pte));
130 }
131 #endif
132 
133 #ifndef pte_mkprivileged
134 static inline pte_t pte_mkprivileged(pte_t pte)
135 {
136 	return __pte(pte_val(pte) & ~_PAGE_USER);
137 }
138 #endif
139 
140 #ifndef pte_mkuser
141 static inline pte_t pte_mkuser(pte_t pte)
142 {
143 	return __pte(pte_val(pte) | _PAGE_USER);
144 }
145 #endif
146 
147 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
148 {
149 	return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot));
150 }
151 
152 static inline int pte_swp_exclusive(pte_t pte)
153 {
154 	return pte_val(pte) & _PAGE_SWP_EXCLUSIVE;
155 }
156 
157 static inline pte_t pte_swp_mkexclusive(pte_t pte)
158 {
159 	return __pte(pte_val(pte) | _PAGE_SWP_EXCLUSIVE);
160 }
161 
162 static inline pte_t pte_swp_clear_exclusive(pte_t pte)
163 {
164 	return __pte(pte_val(pte) & ~_PAGE_SWP_EXCLUSIVE);
165 }
166 
167 /* This low level function performs the actual PTE insertion
168  * Setting the PTE depends on the MMU type and other factors. It's
169  * an horrible mess that I'm not going to try to clean up now but
170  * I'm keeping it in one place rather than spread around
171  */
172 static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr,
173 				pte_t *ptep, pte_t pte, int percpu)
174 {
175 	/* Second case is 32-bit with 64-bit PTE.  In this case, we
176 	 * can just store as long as we do the two halves in the right order
177 	 * with a barrier in between.
178 	 * In the percpu case, we also fallback to the simple update
179 	 */
180 	if (IS_ENABLED(CONFIG_PPC32) && IS_ENABLED(CONFIG_PTE_64BIT) && !percpu) {
181 		__asm__ __volatile__("\
182 			stw%X0 %2,%0\n\
183 			mbar\n\
184 			stw%X1 %L2,%1"
185 		: "=m" (*ptep), "=m" (*((unsigned char *)ptep+4))
186 		: "r" (pte) : "memory");
187 		return;
188 	}
189 	/* Anything else just stores the PTE normally. That covers all 64-bit
190 	 * cases, and 32-bit non-hash with 32-bit PTEs.
191 	 */
192 #if defined(CONFIG_PPC_8xx) && defined(CONFIG_PPC_16K_PAGES)
193 	ptep->pte3 = ptep->pte2 = ptep->pte1 = ptep->pte = pte_val(pte);
194 #else
195 	*ptep = pte;
196 #endif
197 
198 	/*
199 	 * With hardware tablewalk, a sync is needed to ensure that
200 	 * subsequent accesses see the PTE we just wrote.  Unlike userspace
201 	 * mappings, we can't tolerate spurious faults, so make sure
202 	 * the new PTE will be seen the first time.
203 	 */
204 	if (IS_ENABLED(CONFIG_PPC_BOOK3E_64) && is_kernel_addr(addr))
205 		mb();
206 }
207 
208 
209 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
210 extern int ptep_set_access_flags(struct vm_area_struct *vma, unsigned long address,
211 				 pte_t *ptep, pte_t entry, int dirty);
212 
213 /*
214  * Macro to mark a page protection value as "uncacheable".
215  */
216 
217 #define _PAGE_CACHE_CTL	(_PAGE_COHERENT | _PAGE_GUARDED | _PAGE_NO_CACHE | \
218 			 _PAGE_WRITETHRU)
219 
220 #define pgprot_noncached(prot)	  (__pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | \
221 				            _PAGE_NO_CACHE | _PAGE_GUARDED))
222 
223 #define pgprot_noncached_wc(prot) (__pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | \
224 				            _PAGE_NO_CACHE))
225 
226 #define pgprot_cached(prot)       (__pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | \
227 				            _PAGE_COHERENT))
228 
229 #if _PAGE_WRITETHRU != 0
230 #define pgprot_cached_wthru(prot) (__pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | \
231 				            _PAGE_COHERENT | _PAGE_WRITETHRU))
232 #else
233 #define pgprot_cached_wthru(prot)	pgprot_noncached(prot)
234 #endif
235 
236 #define pgprot_cached_noncoherent(prot) \
237 		(__pgprot(pgprot_val(prot) & ~_PAGE_CACHE_CTL))
238 
239 #define pgprot_writecombine pgprot_noncached_wc
240 
241 struct file;
242 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
243 				     unsigned long size, pgprot_t vma_prot);
244 #define __HAVE_PHYS_MEM_ACCESS_PROT
245 
246 #ifdef CONFIG_HUGETLB_PAGE
247 static inline int hugepd_ok(hugepd_t hpd)
248 {
249 #ifdef CONFIG_PPC_8xx
250 	return ((hpd_val(hpd) & _PMD_PAGE_MASK) == _PMD_PAGE_8M);
251 #else
252 	/* We clear the top bit to indicate hugepd */
253 	return (hpd_val(hpd) && (hpd_val(hpd) & PD_HUGE) == 0);
254 #endif
255 }
256 
257 static inline int pmd_huge(pmd_t pmd)
258 {
259 	return 0;
260 }
261 
262 static inline int pud_huge(pud_t pud)
263 {
264 	return 0;
265 }
266 
267 #define is_hugepd(hpd)		(hugepd_ok(hpd))
268 #endif
269 
270 /*
271  * This gets called at the end of handling a page fault, when
272  * the kernel has put a new PTE into the page table for the process.
273  * We use it to ensure coherency between the i-cache and d-cache
274  * for the page which has just been mapped in.
275  */
276 #if defined(CONFIG_PPC_E500) && defined(CONFIG_HUGETLB_PAGE)
277 void update_mmu_cache_range(struct vm_fault *vmf, struct vm_area_struct *vma,
278 		unsigned long address, pte_t *ptep, unsigned int nr);
279 #else
280 static inline void update_mmu_cache_range(struct vm_fault *vmf,
281 		struct vm_area_struct *vma, unsigned long address,
282 		pte_t *ptep, unsigned int nr) {}
283 #endif
284 
285 #endif /* __ASSEMBLY__ */
286 #endif
287