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 | \
15 				 _PAGE_NO_CACHE | _PAGE_GUARDED)
16 #define PAGE_KERNEL_X	__pgprot(_PAGE_BASE | _PAGE_KERNEL_RWX)
17 #define PAGE_KERNEL_RO	__pgprot(_PAGE_BASE | _PAGE_KERNEL_RO)
18 #define PAGE_KERNEL_ROX	__pgprot(_PAGE_BASE | _PAGE_KERNEL_ROX)
19 
20 /*
21  * Protection used for kernel text. We want the debuggers to be able to
22  * set breakpoints anywhere, so don't write protect the kernel text
23  * on platforms where such control is possible.
24  */
25 #if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || defined(CONFIG_BDI_SWITCH) ||\
26 	defined(CONFIG_KPROBES) || defined(CONFIG_DYNAMIC_FTRACE)
27 #define PAGE_KERNEL_TEXT	PAGE_KERNEL_X
28 #else
29 #define PAGE_KERNEL_TEXT	PAGE_KERNEL_ROX
30 #endif
31 
32 /* Make modules code happy. We don't set RO yet */
33 #define PAGE_KERNEL_EXEC	PAGE_KERNEL_X
34 
35 /* Advertise special mapping type for AGP */
36 #define PAGE_AGP		(PAGE_KERNEL_NC)
37 #define HAVE_PAGE_AGP
38 
39 #ifndef __ASSEMBLY__
40 
41 /* Generic accessors to PTE bits */
42 #ifndef pte_write
43 static inline int pte_write(pte_t pte)
44 {
45 	return pte_val(pte) & _PAGE_RW;
46 }
47 #endif
48 static inline int pte_read(pte_t pte)		{ return 1; }
49 static inline int pte_dirty(pte_t pte)		{ return pte_val(pte) & _PAGE_DIRTY; }
50 static inline int pte_special(pte_t pte)	{ return pte_val(pte) & _PAGE_SPECIAL; }
51 static inline int pte_none(pte_t pte)		{ return (pte_val(pte) & ~_PTE_NONE_MASK) == 0; }
52 static inline bool pte_hashpte(pte_t pte)	{ return false; }
53 static inline bool pte_ci(pte_t pte)		{ return pte_val(pte) & _PAGE_NO_CACHE; }
54 static inline bool pte_exec(pte_t pte)		{ return pte_val(pte) & _PAGE_EXEC; }
55 
56 #ifdef CONFIG_NUMA_BALANCING
57 /*
58  * These work without NUMA balancing but the kernel does not care. See the
59  * comment in include/asm-generic/pgtable.h . On powerpc, this will only
60  * work for user pages and always return true for kernel pages.
61  */
62 static inline int pte_protnone(pte_t pte)
63 {
64 	return pte_present(pte) && !pte_user(pte);
65 }
66 
67 static inline int pmd_protnone(pmd_t pmd)
68 {
69 	return pte_protnone(pmd_pte(pmd));
70 }
71 #endif /* CONFIG_NUMA_BALANCING */
72 
73 static inline int pte_present(pte_t pte)
74 {
75 	return pte_val(pte) & _PAGE_PRESENT;
76 }
77 
78 static inline bool pte_hw_valid(pte_t pte)
79 {
80 	return pte_val(pte) & _PAGE_PRESENT;
81 }
82 
83 /*
84  * Don't just check for any non zero bits in __PAGE_USER, since for book3e
85  * and PTE_64BIT, PAGE_KERNEL_X contains _PAGE_BAP_SR which is also in
86  * _PAGE_USER.  Need to explicitly match _PAGE_BAP_UR bit in that case too.
87  */
88 #ifndef pte_user
89 static inline bool pte_user(pte_t pte)
90 {
91 	return (pte_val(pte) & _PAGE_USER) == _PAGE_USER;
92 }
93 #endif
94 
95 /*
96  * We only find page table entry in the last level
97  * Hence no need for other accessors
98  */
99 #define pte_access_permitted pte_access_permitted
100 static inline bool pte_access_permitted(pte_t pte, bool write)
101 {
102 	/*
103 	 * A read-only access is controlled by _PAGE_USER bit.
104 	 * We have _PAGE_READ set for WRITE and EXECUTE
105 	 */
106 	if (!pte_present(pte) || !pte_user(pte) || !pte_read(pte))
107 		return false;
108 
109 	if (write && !pte_write(pte))
110 		return false;
111 
112 	return true;
113 }
114 
115 /* Conversion functions: convert a page and protection to a page entry,
116  * and a page entry and page directory to the page they refer to.
117  *
118  * Even if PTEs can be unsigned long long, a PFN is always an unsigned
119  * long for now.
120  */
121 static inline pte_t pfn_pte(unsigned long pfn, pgprot_t pgprot) {
122 	return __pte(((pte_basic_t)(pfn) << PTE_RPN_SHIFT) |
123 		     pgprot_val(pgprot)); }
124 static inline unsigned long pte_pfn(pte_t pte)	{
125 	return pte_val(pte) >> PTE_RPN_SHIFT; }
126 
127 /* Generic modifiers for PTE bits */
128 static inline pte_t pte_exprotect(pte_t pte)
129 {
130 	return __pte(pte_val(pte) & ~_PAGE_EXEC);
131 }
132 
133 #ifndef pte_mkclean
134 static inline pte_t pte_mkclean(pte_t pte)
135 {
136 	return __pte(pte_val(pte) & ~_PAGE_DIRTY);
137 }
138 #endif
139 
140 static inline pte_t pte_mkold(pte_t pte)
141 {
142 	return __pte(pte_val(pte) & ~_PAGE_ACCESSED);
143 }
144 
145 static inline pte_t pte_mkpte(pte_t pte)
146 {
147 	return pte;
148 }
149 
150 static inline pte_t pte_mkspecial(pte_t pte)
151 {
152 	return __pte(pte_val(pte) | _PAGE_SPECIAL);
153 }
154 
155 #ifndef pte_mkhuge
156 static inline pte_t pte_mkhuge(pte_t pte)
157 {
158 	return __pte(pte_val(pte));
159 }
160 #endif
161 
162 #ifndef pte_mkprivileged
163 static inline pte_t pte_mkprivileged(pte_t pte)
164 {
165 	return __pte(pte_val(pte) & ~_PAGE_USER);
166 }
167 #endif
168 
169 #ifndef pte_mkuser
170 static inline pte_t pte_mkuser(pte_t pte)
171 {
172 	return __pte(pte_val(pte) | _PAGE_USER);
173 }
174 #endif
175 
176 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
177 {
178 	return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot));
179 }
180 
181 /* Insert a PTE, top-level function is out of line. It uses an inline
182  * low level function in the respective pgtable-* files
183  */
184 extern void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
185 		       pte_t pte);
186 
187 /* This low level function performs the actual PTE insertion
188  * Setting the PTE depends on the MMU type and other factors. It's
189  * an horrible mess that I'm not going to try to clean up now but
190  * I'm keeping it in one place rather than spread around
191  */
192 static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr,
193 				pte_t *ptep, pte_t pte, int percpu)
194 {
195 	/* Second case is 32-bit with 64-bit PTE.  In this case, we
196 	 * can just store as long as we do the two halves in the right order
197 	 * with a barrier in between.
198 	 * In the percpu case, we also fallback to the simple update
199 	 */
200 	if (IS_ENABLED(CONFIG_PPC32) && IS_ENABLED(CONFIG_PTE_64BIT) && !percpu) {
201 		__asm__ __volatile__("\
202 			stw%U0%X0 %2,%0\n\
203 			eieio\n\
204 			stw%U0%X0 %L2,%1"
205 		: "=m" (*ptep), "=m" (*((unsigned char *)ptep+4))
206 		: "r" (pte) : "memory");
207 		return;
208 	}
209 	/* Anything else just stores the PTE normally. That covers all 64-bit
210 	 * cases, and 32-bit non-hash with 32-bit PTEs.
211 	 */
212 #if defined(CONFIG_PPC_8xx) && defined(CONFIG_PPC_16K_PAGES)
213 	ptep->pte = ptep->pte1 = ptep->pte2 = ptep->pte3 = pte_val(pte);
214 #else
215 	*ptep = pte;
216 #endif
217 
218 	/*
219 	 * With hardware tablewalk, a sync is needed to ensure that
220 	 * subsequent accesses see the PTE we just wrote.  Unlike userspace
221 	 * mappings, we can't tolerate spurious faults, so make sure
222 	 * the new PTE will be seen the first time.
223 	 */
224 	if (IS_ENABLED(CONFIG_PPC_BOOK3E_64) && is_kernel_addr(addr))
225 		mb();
226 }
227 
228 
229 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
230 extern int ptep_set_access_flags(struct vm_area_struct *vma, unsigned long address,
231 				 pte_t *ptep, pte_t entry, int dirty);
232 
233 /*
234  * Macro to mark a page protection value as "uncacheable".
235  */
236 
237 #define _PAGE_CACHE_CTL	(_PAGE_COHERENT | _PAGE_GUARDED | _PAGE_NO_CACHE | \
238 			 _PAGE_WRITETHRU)
239 
240 #define pgprot_noncached(prot)	  (__pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | \
241 				            _PAGE_NO_CACHE | _PAGE_GUARDED))
242 
243 #define pgprot_noncached_wc(prot) (__pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | \
244 				            _PAGE_NO_CACHE))
245 
246 #define pgprot_cached(prot)       (__pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | \
247 				            _PAGE_COHERENT))
248 
249 #if _PAGE_WRITETHRU != 0
250 #define pgprot_cached_wthru(prot) (__pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | \
251 				            _PAGE_COHERENT | _PAGE_WRITETHRU))
252 #else
253 #define pgprot_cached_wthru(prot)	pgprot_noncached(prot)
254 #endif
255 
256 #define pgprot_cached_noncoherent(prot) \
257 		(__pgprot(pgprot_val(prot) & ~_PAGE_CACHE_CTL))
258 
259 #define pgprot_writecombine pgprot_noncached_wc
260 
261 struct file;
262 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
263 				     unsigned long size, pgprot_t vma_prot);
264 #define __HAVE_PHYS_MEM_ACCESS_PROT
265 
266 #ifdef CONFIG_HUGETLB_PAGE
267 static inline int hugepd_ok(hugepd_t hpd)
268 {
269 #ifdef CONFIG_PPC_8xx
270 	return ((hpd_val(hpd) & 0x4) != 0);
271 #else
272 	/* We clear the top bit to indicate hugepd */
273 	return (hpd_val(hpd) && (hpd_val(hpd) & PD_HUGE) == 0);
274 #endif
275 }
276 
277 static inline int pmd_huge(pmd_t pmd)
278 {
279 	return 0;
280 }
281 
282 static inline int pud_huge(pud_t pud)
283 {
284 	return 0;
285 }
286 
287 static inline int pgd_huge(pgd_t pgd)
288 {
289 	return 0;
290 }
291 #define pgd_huge		pgd_huge
292 
293 #define is_hugepd(hpd)		(hugepd_ok(hpd))
294 #endif
295 
296 /*
297  * This gets called at the end of handling a page fault, when
298  * the kernel has put a new PTE into the page table for the process.
299  * We use it to ensure coherency between the i-cache and d-cache
300  * for the page which has just been mapped in.
301  */
302 #if defined(CONFIG_PPC_FSL_BOOK3E) && defined(CONFIG_HUGETLB_PAGE)
303 void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep);
304 #else
305 static inline
306 void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep) {}
307 #endif
308 
309 #endif /* __ASSEMBLY__ */
310 #endif
311