xref: /linux/arch/powerpc/include/asm/nohash/pgtable.h (revision dc0d1c4519095a6c6bbd9ec4a808674aba502741)
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 #ifndef __ASSEMBLY__
12 
13 /* Generic accessors to PTE bits */
14 static inline int pte_write(pte_t pte)
15 {
16 	return (pte_val(pte) & (_PAGE_RW | _PAGE_RO)) != _PAGE_RO;
17 }
18 static inline int pte_read(pte_t pte)		{ return 1; }
19 static inline int pte_dirty(pte_t pte)		{ return pte_val(pte) & _PAGE_DIRTY; }
20 static inline int pte_special(pte_t pte)	{ return pte_val(pte) & _PAGE_SPECIAL; }
21 static inline int pte_none(pte_t pte)		{ return (pte_val(pte) & ~_PTE_NONE_MASK) == 0; }
22 static inline pgprot_t pte_pgprot(pte_t pte)	{ return __pgprot(pte_val(pte) & PAGE_PROT_BITS); }
23 
24 #ifdef CONFIG_NUMA_BALANCING
25 /*
26  * These work without NUMA balancing but the kernel does not care. See the
27  * comment in include/asm-generic/pgtable.h . On powerpc, this will only
28  * work for user pages and always return true for kernel pages.
29  */
30 static inline int pte_protnone(pte_t pte)
31 {
32 	return (pte_val(pte) &
33 		(_PAGE_PRESENT | _PAGE_USER)) == _PAGE_PRESENT;
34 }
35 
36 static inline int pmd_protnone(pmd_t pmd)
37 {
38 	return pte_protnone(pmd_pte(pmd));
39 }
40 #endif /* CONFIG_NUMA_BALANCING */
41 
42 static inline int pte_present(pte_t pte)
43 {
44 	return pte_val(pte) & _PAGE_PRESENT;
45 }
46 
47 /*
48  * We only find page table entry in the last level
49  * Hence no need for other accessors
50  */
51 #define pte_access_permitted pte_access_permitted
52 static inline bool pte_access_permitted(pte_t pte, bool write)
53 {
54 	/*
55 	 * A read-only access is controlled by _PAGE_USER bit.
56 	 * We have _PAGE_READ set for WRITE and EXECUTE
57 	 */
58 	if (!pte_present(pte) || !pte_user(pte) || !pte_read(pte))
59 		return false;
60 
61 	if (write && !pte_write(pte))
62 		return false;
63 
64 	return true;
65 }
66 
67 /* Conversion functions: convert a page and protection to a page entry,
68  * and a page entry and page directory to the page they refer to.
69  *
70  * Even if PTEs can be unsigned long long, a PFN is always an unsigned
71  * long for now.
72  */
73 static inline pte_t pfn_pte(unsigned long pfn, pgprot_t pgprot) {
74 	return __pte(((pte_basic_t)(pfn) << PTE_RPN_SHIFT) |
75 		     pgprot_val(pgprot)); }
76 static inline unsigned long pte_pfn(pte_t pte)	{
77 	return pte_val(pte) >> PTE_RPN_SHIFT; }
78 
79 /* Generic modifiers for PTE bits */
80 static inline pte_t pte_wrprotect(pte_t pte)
81 {
82 	pte_basic_t ptev;
83 
84 	ptev = pte_val(pte) & ~(_PAGE_RW | _PAGE_HWWRITE);
85 	ptev |= _PAGE_RO;
86 	return __pte(ptev);
87 }
88 
89 static inline pte_t pte_mkclean(pte_t pte)
90 {
91 	return __pte(pte_val(pte) & ~(_PAGE_DIRTY | _PAGE_HWWRITE));
92 }
93 
94 static inline pte_t pte_mkold(pte_t pte)
95 {
96 	return __pte(pte_val(pte) & ~_PAGE_ACCESSED);
97 }
98 
99 static inline pte_t pte_mkwrite(pte_t pte)
100 {
101 	pte_basic_t ptev;
102 
103 	ptev = pte_val(pte) & ~_PAGE_RO;
104 	ptev |= _PAGE_RW;
105 	return __pte(ptev);
106 }
107 
108 static inline pte_t pte_mkdirty(pte_t pte)
109 {
110 	return __pte(pte_val(pte) | _PAGE_DIRTY);
111 }
112 
113 static inline pte_t pte_mkyoung(pte_t pte)
114 {
115 	return __pte(pte_val(pte) | _PAGE_ACCESSED);
116 }
117 
118 static inline pte_t pte_mkspecial(pte_t pte)
119 {
120 	return __pte(pte_val(pte) | _PAGE_SPECIAL);
121 }
122 
123 static inline pte_t pte_mkhuge(pte_t pte)
124 {
125 	return __pte(pte_val(pte) | _PAGE_HUGE);
126 }
127 
128 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
129 {
130 	return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot));
131 }
132 
133 /* Insert a PTE, top-level function is out of line. It uses an inline
134  * low level function in the respective pgtable-* files
135  */
136 extern void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
137 		       pte_t pte);
138 
139 /* This low level function performs the actual PTE insertion
140  * Setting the PTE depends on the MMU type and other factors. It's
141  * an horrible mess that I'm not going to try to clean up now but
142  * I'm keeping it in one place rather than spread around
143  */
144 static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr,
145 				pte_t *ptep, pte_t pte, int percpu)
146 {
147 	/* Second case is 32-bit with 64-bit PTE.  In this case, we
148 	 * can just store as long as we do the two halves in the right order
149 	 * with a barrier in between.
150 	 * In the percpu case, we also fallback to the simple update
151 	 */
152 	if (IS_ENABLED(CONFIG_PPC32) && IS_ENABLED(CONFIG_PTE_64BIT) && !percpu) {
153 		__asm__ __volatile__("\
154 			stw%U0%X0 %2,%0\n\
155 			eieio\n\
156 			stw%U0%X0 %L2,%1"
157 		: "=m" (*ptep), "=m" (*((unsigned char *)ptep+4))
158 		: "r" (pte) : "memory");
159 		return;
160 	}
161 	/* Anything else just stores the PTE normally. That covers all 64-bit
162 	 * cases, and 32-bit non-hash with 32-bit PTEs.
163 	 */
164 	*ptep = pte;
165 
166 	/*
167 	 * With hardware tablewalk, a sync is needed to ensure that
168 	 * subsequent accesses see the PTE we just wrote.  Unlike userspace
169 	 * mappings, we can't tolerate spurious faults, so make sure
170 	 * the new PTE will be seen the first time.
171 	 */
172 	if (IS_ENABLED(CONFIG_PPC_BOOK3E_64) && is_kernel_addr(addr))
173 		mb();
174 }
175 
176 
177 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
178 extern int ptep_set_access_flags(struct vm_area_struct *vma, unsigned long address,
179 				 pte_t *ptep, pte_t entry, int dirty);
180 
181 /*
182  * Macro to mark a page protection value as "uncacheable".
183  */
184 
185 #define _PAGE_CACHE_CTL	(_PAGE_COHERENT | _PAGE_GUARDED | _PAGE_NO_CACHE | \
186 			 _PAGE_WRITETHRU)
187 
188 #define pgprot_noncached(prot)	  (__pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | \
189 				            _PAGE_NO_CACHE | _PAGE_GUARDED))
190 
191 #define pgprot_noncached_wc(prot) (__pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | \
192 				            _PAGE_NO_CACHE))
193 
194 #define pgprot_cached(prot)       (__pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | \
195 				            _PAGE_COHERENT))
196 
197 #if _PAGE_WRITETHRU != 0
198 #define pgprot_cached_wthru(prot) (__pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | \
199 				            _PAGE_COHERENT | _PAGE_WRITETHRU))
200 #endif
201 
202 #define pgprot_cached_noncoherent(prot) \
203 		(__pgprot(pgprot_val(prot) & ~_PAGE_CACHE_CTL))
204 
205 #define pgprot_writecombine pgprot_noncached_wc
206 
207 struct file;
208 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
209 				     unsigned long size, pgprot_t vma_prot);
210 #define __HAVE_PHYS_MEM_ACCESS_PROT
211 
212 #ifdef CONFIG_HUGETLB_PAGE
213 static inline int hugepd_ok(hugepd_t hpd)
214 {
215 #ifdef CONFIG_PPC_8xx
216 	return ((hpd_val(hpd) & 0x4) != 0);
217 #else
218 	/* We clear the top bit to indicate hugepd */
219 	return (hpd_val(hpd) && (hpd_val(hpd) & PD_HUGE) == 0);
220 #endif
221 }
222 
223 static inline int pmd_huge(pmd_t pmd)
224 {
225 	return 0;
226 }
227 
228 static inline int pud_huge(pud_t pud)
229 {
230 	return 0;
231 }
232 
233 static inline int pgd_huge(pgd_t pgd)
234 {
235 	return 0;
236 }
237 #define pgd_huge		pgd_huge
238 
239 #define is_hugepd(hpd)		(hugepd_ok(hpd))
240 #endif
241 
242 #endif /* __ASSEMBLY__ */
243 #endif
244