1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_POWERPC_NOHASH_32_PGTABLE_H
3 #define _ASM_POWERPC_NOHASH_32_PGTABLE_H
4 
5 #include <asm-generic/pgtable-nopmd.h>
6 
7 #ifndef __ASSEMBLY__
8 #include <linux/sched.h>
9 #include <linux/threads.h>
10 #include <asm/mmu.h>			/* For sub-arch specific PPC_PIN_SIZE */
11 
12 #ifdef CONFIG_44x
13 extern int icache_44x_need_flush;
14 #endif
15 
16 #endif /* __ASSEMBLY__ */
17 
18 #define PTE_INDEX_SIZE	PTE_SHIFT
19 #define PMD_INDEX_SIZE	0
20 #define PUD_INDEX_SIZE	0
21 #define PGD_INDEX_SIZE	(32 - PGDIR_SHIFT)
22 
23 #define PMD_CACHE_INDEX	PMD_INDEX_SIZE
24 #define PUD_CACHE_INDEX	PUD_INDEX_SIZE
25 
26 #ifndef __ASSEMBLY__
27 #define PTE_TABLE_SIZE	(sizeof(pte_t) << PTE_INDEX_SIZE)
28 #define PMD_TABLE_SIZE	0
29 #define PUD_TABLE_SIZE	0
30 #define PGD_TABLE_SIZE	(sizeof(pgd_t) << PGD_INDEX_SIZE)
31 
32 #define PMD_MASKED_BITS (PTE_TABLE_SIZE - 1)
33 #endif	/* __ASSEMBLY__ */
34 
35 #define PTRS_PER_PTE	(1 << PTE_INDEX_SIZE)
36 #define PTRS_PER_PGD	(1 << PGD_INDEX_SIZE)
37 
38 /*
39  * The normal case is that PTEs are 32-bits and we have a 1-page
40  * 1024-entry pgdir pointing to 1-page 1024-entry PTE pages.  -- paulus
41  *
42  * For any >32-bit physical address platform, we can use the following
43  * two level page table layout where the pgdir is 8KB and the MS 13 bits
44  * are an index to the second level table.  The combined pgdir/pmd first
45  * level has 2048 entries and the second level has 512 64-bit PTE entries.
46  * -Matt
47  */
48 /* PGDIR_SHIFT determines what a top-level page table entry can map */
49 #define PGDIR_SHIFT	(PAGE_SHIFT + PTE_INDEX_SIZE)
50 #define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
51 #define PGDIR_MASK	(~(PGDIR_SIZE-1))
52 
53 /* Bits to mask out from a PGD to get to the PUD page */
54 #define PGD_MASKED_BITS		0
55 
56 #define USER_PTRS_PER_PGD	(TASK_SIZE / PGDIR_SIZE)
57 #define FIRST_USER_ADDRESS	0UL
58 
59 #define pte_ERROR(e) \
60 	pr_err("%s:%d: bad pte %llx.\n", __FILE__, __LINE__, \
61 		(unsigned long long)pte_val(e))
62 #define pgd_ERROR(e) \
63 	pr_err("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))
64 
65 #ifndef __ASSEMBLY__
66 
67 int map_kernel_page(unsigned long va, phys_addr_t pa, pgprot_t prot);
68 
69 #endif /* !__ASSEMBLY__ */
70 
71 
72 /*
73  * This is the bottom of the PKMAP area with HIGHMEM or an arbitrary
74  * value (for now) on others, from where we can start layout kernel
75  * virtual space that goes below PKMAP and FIXMAP
76  */
77 #include <asm/fixmap.h>
78 
79 /*
80  * ioremap_bot starts at that address. Early ioremaps move down from there,
81  * until mem_init() at which point this becomes the top of the vmalloc
82  * and ioremap space
83  */
84 #ifdef CONFIG_HIGHMEM
85 #define IOREMAP_TOP	PKMAP_BASE
86 #else
87 #define IOREMAP_TOP	FIXADDR_START
88 #endif
89 
90 /* PPC32 shares vmalloc area with ioremap */
91 #define IOREMAP_START	VMALLOC_START
92 #define IOREMAP_END	VMALLOC_END
93 
94 /*
95  * Just any arbitrary offset to the start of the vmalloc VM area: the
96  * current 16MB value just means that there will be a 64MB "hole" after the
97  * physical memory until the kernel virtual memory starts.  That means that
98  * any out-of-bounds memory accesses will hopefully be caught.
99  * The vmalloc() routines leaves a hole of 4kB between each vmalloced
100  * area for the same reason. ;)
101  *
102  * We no longer map larger than phys RAM with the BATs so we don't have
103  * to worry about the VMALLOC_OFFSET causing problems.  We do have to worry
104  * about clashes between our early calls to ioremap() that start growing down
105  * from IOREMAP_TOP being run into the VM area allocations (growing upwards
106  * from VMALLOC_START).  For this reason we have ioremap_bot to check when
107  * we actually run into our mappings setup in the early boot with the VM
108  * system.  This really does become a problem for machines with good amounts
109  * of RAM.  -- Cort
110  */
111 #define VMALLOC_OFFSET (0x1000000) /* 16M */
112 #ifdef PPC_PIN_SIZE
113 #define VMALLOC_START (((ALIGN((long)high_memory, PPC_PIN_SIZE) + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1)))
114 #else
115 #define VMALLOC_START ((((long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1)))
116 #endif
117 
118 #ifdef CONFIG_KASAN_VMALLOC
119 #define VMALLOC_END	ALIGN_DOWN(ioremap_bot, PAGE_SIZE << KASAN_SHADOW_SCALE_SHIFT)
120 #else
121 #define VMALLOC_END	ioremap_bot
122 #endif
123 
124 /*
125  * Bits in a linux-style PTE.  These match the bits in the
126  * (hardware-defined) PowerPC PTE as closely as possible.
127  */
128 
129 #if defined(CONFIG_40x)
130 #include <asm/nohash/32/pte-40x.h>
131 #elif defined(CONFIG_44x)
132 #include <asm/nohash/32/pte-44x.h>
133 #elif defined(CONFIG_FSL_BOOKE) && defined(CONFIG_PTE_64BIT)
134 #include <asm/nohash/pte-book3e.h>
135 #elif defined(CONFIG_FSL_BOOKE)
136 #include <asm/nohash/32/pte-fsl-booke.h>
137 #elif defined(CONFIG_PPC_8xx)
138 #include <asm/nohash/32/pte-8xx.h>
139 #endif
140 
141 /*
142  * Location of the PFN in the PTE. Most 32-bit platforms use the same
143  * as _PAGE_SHIFT here (ie, naturally aligned).
144  * Platform who don't just pre-define the value so we don't override it here.
145  */
146 #ifndef PTE_RPN_SHIFT
147 #define PTE_RPN_SHIFT	(PAGE_SHIFT)
148 #endif
149 
150 /*
151  * The mask covered by the RPN must be a ULL on 32-bit platforms with
152  * 64-bit PTEs.
153  */
154 #if defined(CONFIG_PPC32) && defined(CONFIG_PTE_64BIT)
155 #define PTE_RPN_MASK	(~((1ULL << PTE_RPN_SHIFT) - 1))
156 #else
157 #define PTE_RPN_MASK	(~((1UL << PTE_RPN_SHIFT) - 1))
158 #endif
159 
160 /*
161  * _PAGE_CHG_MASK masks of bits that are to be preserved across
162  * pgprot changes.
163  */
164 #define _PAGE_CHG_MASK	(PTE_RPN_MASK | _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_SPECIAL)
165 
166 #ifndef __ASSEMBLY__
167 
168 #define pte_clear(mm, addr, ptep) \
169 	do { pte_update(mm, addr, ptep, ~0, 0, 0); } while (0)
170 
171 #ifndef pte_mkwrite
172 static inline pte_t pte_mkwrite(pte_t pte)
173 {
174 	return __pte(pte_val(pte) | _PAGE_RW);
175 }
176 #endif
177 
178 static inline pte_t pte_mkdirty(pte_t pte)
179 {
180 	return __pte(pte_val(pte) | _PAGE_DIRTY);
181 }
182 
183 static inline pte_t pte_mkyoung(pte_t pte)
184 {
185 	return __pte(pte_val(pte) | _PAGE_ACCESSED);
186 }
187 
188 #ifndef pte_wrprotect
189 static inline pte_t pte_wrprotect(pte_t pte)
190 {
191 	return __pte(pte_val(pte) & ~_PAGE_RW);
192 }
193 #endif
194 
195 static inline pte_t pte_mkexec(pte_t pte)
196 {
197 	return __pte(pte_val(pte) | _PAGE_EXEC);
198 }
199 
200 #define pmd_none(pmd)		(!pmd_val(pmd))
201 #define	pmd_bad(pmd)		(pmd_val(pmd) & _PMD_BAD)
202 #define	pmd_present(pmd)	(pmd_val(pmd) & _PMD_PRESENT_MASK)
203 static inline void pmd_clear(pmd_t *pmdp)
204 {
205 	*pmdp = __pmd(0);
206 }
207 
208 /*
209  * PTE updates. This function is called whenever an existing
210  * valid PTE is updated. This does -not- include set_pte_at()
211  * which nowadays only sets a new PTE.
212  *
213  * Depending on the type of MMU, we may need to use atomic updates
214  * and the PTE may be either 32 or 64 bit wide. In the later case,
215  * when using atomic updates, only the low part of the PTE is
216  * accessed atomically.
217  *
218  * In addition, on 44x, we also maintain a global flag indicating
219  * that an executable user mapping was modified, which is needed
220  * to properly flush the virtually tagged instruction cache of
221  * those implementations.
222  *
223  * On the 8xx, the page tables are a bit special. For 16k pages, we have
224  * 4 identical entries. For 512k pages, we have 128 entries as if it was
225  * 4k pages, but they are flagged as 512k pages for the hardware.
226  * For other page sizes, we have a single entry in the table.
227  */
228 #ifdef CONFIG_PPC_8xx
229 static pmd_t *pmd_off(struct mm_struct *mm, unsigned long addr);
230 
231 static inline pte_basic_t pte_update(struct mm_struct *mm, unsigned long addr, pte_t *p,
232 				     unsigned long clr, unsigned long set, int huge)
233 {
234 	pte_basic_t *entry = &p->pte;
235 	pte_basic_t old = pte_val(*p);
236 	pte_basic_t new = (old & ~(pte_basic_t)clr) | set;
237 	int num, i;
238 	pmd_t *pmd = pmd_off(mm, addr);
239 
240 	if (!huge)
241 		num = PAGE_SIZE / SZ_4K;
242 	else if ((pmd_val(*pmd) & _PMD_PAGE_MASK) != _PMD_PAGE_8M)
243 		num = SZ_512K / SZ_4K;
244 	else
245 		num = 1;
246 
247 	for (i = 0; i < num; i++, entry++, new += SZ_4K)
248 		*entry = new;
249 
250 	return old;
251 }
252 
253 #ifdef CONFIG_PPC_16K_PAGES
254 #define __HAVE_ARCH_PTEP_GET
255 static inline pte_t ptep_get(pte_t *ptep)
256 {
257 	pte_basic_t val = READ_ONCE(ptep->pte);
258 	pte_t pte = {val, val, val, val};
259 
260 	return pte;
261 }
262 #endif /* CONFIG_PPC_16K_PAGES */
263 
264 #else
265 static inline pte_basic_t pte_update(struct mm_struct *mm, unsigned long addr, pte_t *p,
266 				     unsigned long clr, unsigned long set, int huge)
267 {
268 	pte_basic_t old = pte_val(*p);
269 	pte_basic_t new = (old & ~(pte_basic_t)clr) | set;
270 
271 	*p = __pte(new);
272 
273 #ifdef CONFIG_44x
274 	if ((old & _PAGE_USER) && (old & _PAGE_EXEC))
275 		icache_44x_need_flush = 1;
276 #endif
277 	return old;
278 }
279 #endif
280 
281 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
282 static inline int __ptep_test_and_clear_young(struct mm_struct *mm,
283 					      unsigned long addr, pte_t *ptep)
284 {
285 	unsigned long old;
286 	old = pte_update(mm, addr, ptep, _PAGE_ACCESSED, 0, 0);
287 	return (old & _PAGE_ACCESSED) != 0;
288 }
289 #define ptep_test_and_clear_young(__vma, __addr, __ptep) \
290 	__ptep_test_and_clear_young((__vma)->vm_mm, __addr, __ptep)
291 
292 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
293 static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
294 				       pte_t *ptep)
295 {
296 	return __pte(pte_update(mm, addr, ptep, ~0, 0, 0));
297 }
298 
299 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
300 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr,
301 				      pte_t *ptep)
302 {
303 	unsigned long clr = ~pte_val(pte_wrprotect(__pte(~0)));
304 	unsigned long set = pte_val(pte_wrprotect(__pte(0)));
305 
306 	pte_update(mm, addr, ptep, clr, set, 0);
307 }
308 
309 static inline void __ptep_set_access_flags(struct vm_area_struct *vma,
310 					   pte_t *ptep, pte_t entry,
311 					   unsigned long address,
312 					   int psize)
313 {
314 	pte_t pte_set = pte_mkyoung(pte_mkdirty(pte_mkwrite(pte_mkexec(__pte(0)))));
315 	pte_t pte_clr = pte_mkyoung(pte_mkdirty(pte_mkwrite(pte_mkexec(__pte(~0)))));
316 	unsigned long set = pte_val(entry) & pte_val(pte_set);
317 	unsigned long clr = ~pte_val(entry) & ~pte_val(pte_clr);
318 	int huge = psize > mmu_virtual_psize ? 1 : 0;
319 
320 	pte_update(vma->vm_mm, address, ptep, clr, set, huge);
321 
322 	flush_tlb_page(vma, address);
323 }
324 
325 static inline int pte_young(pte_t pte)
326 {
327 	return pte_val(pte) & _PAGE_ACCESSED;
328 }
329 
330 #define __HAVE_ARCH_PTE_SAME
331 #define pte_same(A,B)	((pte_val(A) ^ pte_val(B)) == 0)
332 
333 /*
334  * Note that on Book E processors, the pmd contains the kernel virtual
335  * (lowmem) address of the pte page.  The physical address is less useful
336  * because everything runs with translation enabled (even the TLB miss
337  * handler).  On everything else the pmd contains the physical address
338  * of the pte page.  -- paulus
339  */
340 #ifndef CONFIG_BOOKE
341 #define pmd_page(pmd)		\
342 	pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT)
343 #else
344 #define pmd_page_vaddr(pmd)	\
345 	((unsigned long)(pmd_val(pmd) & ~(PTE_TABLE_SIZE - 1)))
346 #define pmd_page(pmd)		\
347 	pfn_to_page((__pa(pmd_val(pmd)) >> PAGE_SHIFT))
348 #endif
349 
350 /*
351  * Encode and decode a swap entry.
352  * Note that the bits we use in a PTE for representing a swap entry
353  * must not include the _PAGE_PRESENT bit.
354  *   -- paulus
355  */
356 #define __swp_type(entry)		((entry).val & 0x1f)
357 #define __swp_offset(entry)		((entry).val >> 5)
358 #define __swp_entry(type, offset)	((swp_entry_t) { (type) | ((offset) << 5) })
359 #define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) >> 3 })
360 #define __swp_entry_to_pte(x)		((pte_t) { (x).val << 3 })
361 
362 #endif /* !__ASSEMBLY__ */
363 
364 #endif /* __ASM_POWERPC_NOHASH_32_PGTABLE_H */
365