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 #define __ARCH_USE_5LEVEL_HACK
6 #include <asm-generic/pgtable-nopmd.h>
7 
8 #ifndef __ASSEMBLY__
9 #include <linux/sched.h>
10 #include <linux/threads.h>
11 #include <asm/mmu.h>			/* For sub-arch specific PPC_PIN_SIZE */
12 #include <asm/asm-405.h>
13 
14 extern unsigned long ioremap_bot;
15 
16 #ifdef CONFIG_44x
17 extern int icache_44x_need_flush;
18 #endif
19 
20 #endif /* __ASSEMBLY__ */
21 
22 #define PTE_INDEX_SIZE	PTE_SHIFT
23 #define PMD_INDEX_SIZE	0
24 #define PUD_INDEX_SIZE	0
25 #define PGD_INDEX_SIZE	(32 - PGDIR_SHIFT)
26 
27 #define PMD_CACHE_INDEX	PMD_INDEX_SIZE
28 #define PUD_CACHE_INDEX	PUD_INDEX_SIZE
29 
30 #ifndef __ASSEMBLY__
31 #define PTE_TABLE_SIZE	(sizeof(pte_t) << PTE_INDEX_SIZE)
32 #define PMD_TABLE_SIZE	0
33 #define PUD_TABLE_SIZE	0
34 #define PGD_TABLE_SIZE	(sizeof(pgd_t) << PGD_INDEX_SIZE)
35 #endif	/* __ASSEMBLY__ */
36 
37 #define PTRS_PER_PTE	(1 << PTE_INDEX_SIZE)
38 #define PTRS_PER_PGD	(1 << PGD_INDEX_SIZE)
39 
40 /*
41  * The normal case is that PTEs are 32-bits and we have a 1-page
42  * 1024-entry pgdir pointing to 1-page 1024-entry PTE pages.  -- paulus
43  *
44  * For any >32-bit physical address platform, we can use the following
45  * two level page table layout where the pgdir is 8KB and the MS 13 bits
46  * are an index to the second level table.  The combined pgdir/pmd first
47  * level has 2048 entries and the second level has 512 64-bit PTE entries.
48  * -Matt
49  */
50 /* PGDIR_SHIFT determines what a top-level page table entry can map */
51 #define PGDIR_SHIFT	(PAGE_SHIFT + PTE_INDEX_SIZE)
52 #define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
53 #define PGDIR_MASK	(~(PGDIR_SIZE-1))
54 
55 /* Bits to mask out from a PGD to get to the PUD page */
56 #define PGD_MASKED_BITS		0
57 
58 #define USER_PTRS_PER_PGD	(TASK_SIZE / PGDIR_SIZE)
59 #define FIRST_USER_ADDRESS	0UL
60 
61 #define pte_ERROR(e) \
62 	pr_err("%s:%d: bad pte %llx.\n", __FILE__, __LINE__, \
63 		(unsigned long long)pte_val(e))
64 #define pgd_ERROR(e) \
65 	pr_err("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))
66 
67 /*
68  * This is the bottom of the PKMAP area with HIGHMEM or an arbitrary
69  * value (for now) on others, from where we can start layout kernel
70  * virtual space that goes below PKMAP and FIXMAP
71  */
72 #ifdef CONFIG_HIGHMEM
73 #define KVIRT_TOP	PKMAP_BASE
74 #else
75 #define KVIRT_TOP	(0xfe000000UL)	/* for now, could be FIXMAP_BASE ? */
76 #endif
77 
78 /*
79  * ioremap_bot starts at that address. Early ioremaps move down from there,
80  * until mem_init() at which point this becomes the top of the vmalloc
81  * and ioremap space
82  */
83 #ifdef CONFIG_NOT_COHERENT_CACHE
84 #define IOREMAP_TOP	((KVIRT_TOP - CONFIG_CONSISTENT_SIZE) & PAGE_MASK)
85 #else
86 #define IOREMAP_TOP	KVIRT_TOP
87 #endif
88 
89 /*
90  * Just any arbitrary offset to the start of the vmalloc VM area: the
91  * current 16MB value just means that there will be a 64MB "hole" after the
92  * physical memory until the kernel virtual memory starts.  That means that
93  * any out-of-bounds memory accesses will hopefully be caught.
94  * The vmalloc() routines leaves a hole of 4kB between each vmalloced
95  * area for the same reason. ;)
96  *
97  * We no longer map larger than phys RAM with the BATs so we don't have
98  * to worry about the VMALLOC_OFFSET causing problems.  We do have to worry
99  * about clashes between our early calls to ioremap() that start growing down
100  * from IOREMAP_TOP being run into the VM area allocations (growing upwards
101  * from VMALLOC_START).  For this reason we have ioremap_bot to check when
102  * we actually run into our mappings setup in the early boot with the VM
103  * system.  This really does become a problem for machines with good amounts
104  * of RAM.  -- Cort
105  */
106 #define VMALLOC_OFFSET (0x1000000) /* 16M */
107 #ifdef PPC_PIN_SIZE
108 #define VMALLOC_START (((_ALIGN((long)high_memory, PPC_PIN_SIZE) + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1)))
109 #else
110 #define VMALLOC_START ((((long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1)))
111 #endif
112 #define VMALLOC_END	ioremap_bot
113 
114 /*
115  * Bits in a linux-style PTE.  These match the bits in the
116  * (hardware-defined) PowerPC PTE as closely as possible.
117  */
118 
119 #if defined(CONFIG_40x)
120 #include <asm/nohash/32/pte-40x.h>
121 #elif defined(CONFIG_44x)
122 #include <asm/nohash/32/pte-44x.h>
123 #elif defined(CONFIG_FSL_BOOKE) && defined(CONFIG_PTE_64BIT)
124 #include <asm/nohash/pte-book3e.h>
125 #elif defined(CONFIG_FSL_BOOKE)
126 #include <asm/nohash/32/pte-fsl-booke.h>
127 #elif defined(CONFIG_PPC_8xx)
128 #include <asm/nohash/32/pte-8xx.h>
129 #endif
130 
131 /*
132  * Location of the PFN in the PTE. Most 32-bit platforms use the same
133  * as _PAGE_SHIFT here (ie, naturally aligned).
134  * Platform who don't just pre-define the value so we don't override it here.
135  */
136 #ifndef PTE_RPN_SHIFT
137 #define PTE_RPN_SHIFT	(PAGE_SHIFT)
138 #endif
139 
140 /*
141  * The mask covered by the RPN must be a ULL on 32-bit platforms with
142  * 64-bit PTEs.
143  */
144 #if defined(CONFIG_PPC32) && defined(CONFIG_PTE_64BIT)
145 #define PTE_RPN_MASK	(~((1ULL << PTE_RPN_SHIFT) - 1))
146 #else
147 #define PTE_RPN_MASK	(~((1UL << PTE_RPN_SHIFT) - 1))
148 #endif
149 
150 /*
151  * _PAGE_CHG_MASK masks of bits that are to be preserved across
152  * pgprot changes.
153  */
154 #define _PAGE_CHG_MASK	(PTE_RPN_MASK | _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_SPECIAL)
155 
156 #ifndef __ASSEMBLY__
157 
158 #define pte_clear(mm, addr, ptep) \
159 	do { pte_update(ptep, ~0, 0); } while (0)
160 
161 #ifndef pte_mkwrite
162 static inline pte_t pte_mkwrite(pte_t pte)
163 {
164 	return __pte(pte_val(pte) | _PAGE_RW);
165 }
166 #endif
167 
168 static inline pte_t pte_mkdirty(pte_t pte)
169 {
170 	return __pte(pte_val(pte) | _PAGE_DIRTY);
171 }
172 
173 static inline pte_t pte_mkyoung(pte_t pte)
174 {
175 	return __pte(pte_val(pte) | _PAGE_ACCESSED);
176 }
177 
178 #ifndef pte_wrprotect
179 static inline pte_t pte_wrprotect(pte_t pte)
180 {
181 	return __pte(pte_val(pte) & ~_PAGE_RW);
182 }
183 #endif
184 
185 static inline pte_t pte_mkexec(pte_t pte)
186 {
187 	return __pte(pte_val(pte) | _PAGE_EXEC);
188 }
189 
190 #define pmd_none(pmd)		(!pmd_val(pmd))
191 #define	pmd_bad(pmd)		(pmd_val(pmd) & _PMD_BAD)
192 #define	pmd_present(pmd)	(pmd_val(pmd) & _PMD_PRESENT_MASK)
193 static inline void pmd_clear(pmd_t *pmdp)
194 {
195 	*pmdp = __pmd(0);
196 }
197 
198 
199 
200 /*
201  * PTE updates. This function is called whenever an existing
202  * valid PTE is updated. This does -not- include set_pte_at()
203  * which nowadays only sets a new PTE.
204  *
205  * Depending on the type of MMU, we may need to use atomic updates
206  * and the PTE may be either 32 or 64 bit wide. In the later case,
207  * when using atomic updates, only the low part of the PTE is
208  * accessed atomically.
209  *
210  * In addition, on 44x, we also maintain a global flag indicating
211  * that an executable user mapping was modified, which is needed
212  * to properly flush the virtually tagged instruction cache of
213  * those implementations.
214  */
215 #ifndef CONFIG_PTE_64BIT
216 static inline unsigned long pte_update(pte_t *p,
217 				       unsigned long clr,
218 				       unsigned long set)
219 {
220 #ifdef PTE_ATOMIC_UPDATES
221 	unsigned long old, tmp;
222 
223 	__asm__ __volatile__("\
224 1:	lwarx	%0,0,%3\n\
225 	andc	%1,%0,%4\n\
226 	or	%1,%1,%5\n"
227 	PPC405_ERR77(0,%3)
228 "	stwcx.	%1,0,%3\n\
229 	bne-	1b"
230 	: "=&r" (old), "=&r" (tmp), "=m" (*p)
231 	: "r" (p), "r" (clr), "r" (set), "m" (*p)
232 	: "cc" );
233 #else /* PTE_ATOMIC_UPDATES */
234 	unsigned long old = pte_val(*p);
235 	*p = __pte((old & ~clr) | set);
236 #endif /* !PTE_ATOMIC_UPDATES */
237 
238 #ifdef CONFIG_44x
239 	if ((old & _PAGE_USER) && (old & _PAGE_EXEC))
240 		icache_44x_need_flush = 1;
241 #endif
242 	return old;
243 }
244 #else /* CONFIG_PTE_64BIT */
245 static inline unsigned long long pte_update(pte_t *p,
246 					    unsigned long clr,
247 					    unsigned long set)
248 {
249 #ifdef PTE_ATOMIC_UPDATES
250 	unsigned long long old;
251 	unsigned long tmp;
252 
253 	__asm__ __volatile__("\
254 1:	lwarx	%L0,0,%4\n\
255 	lwzx	%0,0,%3\n\
256 	andc	%1,%L0,%5\n\
257 	or	%1,%1,%6\n"
258 	PPC405_ERR77(0,%3)
259 "	stwcx.	%1,0,%4\n\
260 	bne-	1b"
261 	: "=&r" (old), "=&r" (tmp), "=m" (*p)
262 	: "r" (p), "r" ((unsigned long)(p) + 4), "r" (clr), "r" (set), "m" (*p)
263 	: "cc" );
264 #else /* PTE_ATOMIC_UPDATES */
265 	unsigned long long old = pte_val(*p);
266 	*p = __pte((old & ~(unsigned long long)clr) | set);
267 #endif /* !PTE_ATOMIC_UPDATES */
268 
269 #ifdef CONFIG_44x
270 	if ((old & _PAGE_USER) && (old & _PAGE_EXEC))
271 		icache_44x_need_flush = 1;
272 #endif
273 	return old;
274 }
275 #endif /* CONFIG_PTE_64BIT */
276 
277 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
278 static inline int __ptep_test_and_clear_young(unsigned int context, unsigned long addr, pte_t *ptep)
279 {
280 	unsigned long old;
281 	old = pte_update(ptep, _PAGE_ACCESSED, 0);
282 	return (old & _PAGE_ACCESSED) != 0;
283 }
284 #define ptep_test_and_clear_young(__vma, __addr, __ptep) \
285 	__ptep_test_and_clear_young((__vma)->vm_mm->context.id, __addr, __ptep)
286 
287 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
288 static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
289 				       pte_t *ptep)
290 {
291 	return __pte(pte_update(ptep, ~0, 0));
292 }
293 
294 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
295 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr,
296 				      pte_t *ptep)
297 {
298 	unsigned long clr = ~pte_val(pte_wrprotect(__pte(~0)));
299 	unsigned long set = pte_val(pte_wrprotect(__pte(0)));
300 
301 	pte_update(ptep, clr, set);
302 }
303 
304 static inline void __ptep_set_access_flags(struct vm_area_struct *vma,
305 					   pte_t *ptep, pte_t entry,
306 					   unsigned long address,
307 					   int psize)
308 {
309 	pte_t pte_set = pte_mkyoung(pte_mkdirty(pte_mkwrite(pte_mkexec(__pte(0)))));
310 	pte_t pte_clr = pte_mkyoung(pte_mkdirty(pte_mkwrite(pte_mkexec(__pte(~0)))));
311 	unsigned long set = pte_val(entry) & pte_val(pte_set);
312 	unsigned long clr = ~pte_val(entry) & ~pte_val(pte_clr);
313 
314 	pte_update(ptep, clr, set);
315 
316 	flush_tlb_page(vma, address);
317 }
318 
319 static inline int pte_young(pte_t pte)
320 {
321 	return pte_val(pte) & _PAGE_ACCESSED;
322 }
323 
324 #define __HAVE_ARCH_PTE_SAME
325 #define pte_same(A,B)	((pte_val(A) ^ pte_val(B)) == 0)
326 
327 /*
328  * Note that on Book E processors, the pmd contains the kernel virtual
329  * (lowmem) address of the pte page.  The physical address is less useful
330  * because everything runs with translation enabled (even the TLB miss
331  * handler).  On everything else the pmd contains the physical address
332  * of the pte page.  -- paulus
333  */
334 #ifndef CONFIG_BOOKE
335 #define pmd_page_vaddr(pmd)	\
336 	((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
337 #define pmd_page(pmd)		\
338 	pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT)
339 #else
340 #define pmd_page_vaddr(pmd)	\
341 	((unsigned long) (pmd_val(pmd) & PAGE_MASK))
342 #define pmd_page(pmd)		\
343 	pfn_to_page((__pa(pmd_val(pmd)) >> PAGE_SHIFT))
344 #endif
345 
346 /* to find an entry in a kernel page-table-directory */
347 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
348 
349 /* to find an entry in a page-table-directory */
350 #define pgd_index(address)	 ((address) >> PGDIR_SHIFT)
351 #define pgd_offset(mm, address)	 ((mm)->pgd + pgd_index(address))
352 
353 /* Find an entry in the third-level page table.. */
354 #define pte_index(address)		\
355 	(((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
356 #define pte_offset_kernel(dir, addr)	\
357 	(pmd_bad(*(dir)) ? NULL : (pte_t *)pmd_page_vaddr(*(dir)) + \
358 				  pte_index(addr))
359 #define pte_offset_map(dir, addr)		\
360 	((pte_t *) kmap_atomic(pmd_page(*(dir))) + pte_index(addr))
361 #define pte_unmap(pte)		kunmap_atomic(pte)
362 
363 /*
364  * Encode and decode a swap entry.
365  * Note that the bits we use in a PTE for representing a swap entry
366  * must not include the _PAGE_PRESENT bit.
367  *   -- paulus
368  */
369 #define __swp_type(entry)		((entry).val & 0x1f)
370 #define __swp_offset(entry)		((entry).val >> 5)
371 #define __swp_entry(type, offset)	((swp_entry_t) { (type) | ((offset) << 5) })
372 #define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) >> 3 })
373 #define __swp_entry_to_pte(x)		((pte_t) { (x).val << 3 })
374 
375 int map_kernel_page(unsigned long va, phys_addr_t pa, pgprot_t prot);
376 
377 #endif /* !__ASSEMBLY__ */
378 
379 #endif /* __ASM_POWERPC_NOHASH_32_PGTABLE_H */
380