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 #ifdef CONFIG_44x
15 extern int icache_44x_need_flush;
16 #endif
17 
18 #endif /* __ASSEMBLY__ */
19 
20 #define PTE_INDEX_SIZE	PTE_SHIFT
21 #define PMD_INDEX_SIZE	0
22 #define PUD_INDEX_SIZE	0
23 #define PGD_INDEX_SIZE	(32 - PGDIR_SHIFT)
24 
25 #define PMD_CACHE_INDEX	PMD_INDEX_SIZE
26 #define PUD_CACHE_INDEX	PUD_INDEX_SIZE
27 
28 #ifndef __ASSEMBLY__
29 #define PTE_TABLE_SIZE	(sizeof(pte_t) << PTE_INDEX_SIZE)
30 #define PMD_TABLE_SIZE	0
31 #define PUD_TABLE_SIZE	0
32 #define PGD_TABLE_SIZE	(sizeof(pgd_t) << PGD_INDEX_SIZE)
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 #define VMALLOC_END	ioremap_bot
118 
119 /*
120  * Bits in a linux-style PTE.  These match the bits in the
121  * (hardware-defined) PowerPC PTE as closely as possible.
122  */
123 
124 #if defined(CONFIG_40x)
125 #include <asm/nohash/32/pte-40x.h>
126 #elif defined(CONFIG_44x)
127 #include <asm/nohash/32/pte-44x.h>
128 #elif defined(CONFIG_FSL_BOOKE) && defined(CONFIG_PTE_64BIT)
129 #include <asm/nohash/pte-book3e.h>
130 #elif defined(CONFIG_FSL_BOOKE)
131 #include <asm/nohash/32/pte-fsl-booke.h>
132 #elif defined(CONFIG_PPC_8xx)
133 #include <asm/nohash/32/pte-8xx.h>
134 #endif
135 
136 /*
137  * Location of the PFN in the PTE. Most 32-bit platforms use the same
138  * as _PAGE_SHIFT here (ie, naturally aligned).
139  * Platform who don't just pre-define the value so we don't override it here.
140  */
141 #ifndef PTE_RPN_SHIFT
142 #define PTE_RPN_SHIFT	(PAGE_SHIFT)
143 #endif
144 
145 /*
146  * The mask covered by the RPN must be a ULL on 32-bit platforms with
147  * 64-bit PTEs.
148  */
149 #if defined(CONFIG_PPC32) && defined(CONFIG_PTE_64BIT)
150 #define PTE_RPN_MASK	(~((1ULL << PTE_RPN_SHIFT) - 1))
151 #else
152 #define PTE_RPN_MASK	(~((1UL << PTE_RPN_SHIFT) - 1))
153 #endif
154 
155 /*
156  * _PAGE_CHG_MASK masks of bits that are to be preserved across
157  * pgprot changes.
158  */
159 #define _PAGE_CHG_MASK	(PTE_RPN_MASK | _PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_SPECIAL)
160 
161 #ifndef __ASSEMBLY__
162 
163 #define pte_clear(mm, addr, ptep) \
164 	do { pte_update(ptep, ~0, 0); } while (0)
165 
166 #ifndef pte_mkwrite
167 static inline pte_t pte_mkwrite(pte_t pte)
168 {
169 	return __pte(pte_val(pte) | _PAGE_RW);
170 }
171 #endif
172 
173 static inline pte_t pte_mkdirty(pte_t pte)
174 {
175 	return __pte(pte_val(pte) | _PAGE_DIRTY);
176 }
177 
178 static inline pte_t pte_mkyoung(pte_t pte)
179 {
180 	return __pte(pte_val(pte) | _PAGE_ACCESSED);
181 }
182 
183 #ifndef pte_wrprotect
184 static inline pte_t pte_wrprotect(pte_t pte)
185 {
186 	return __pte(pte_val(pte) & ~_PAGE_RW);
187 }
188 #endif
189 
190 static inline pte_t pte_mkexec(pte_t pte)
191 {
192 	return __pte(pte_val(pte) | _PAGE_EXEC);
193 }
194 
195 #define pmd_none(pmd)		(!pmd_val(pmd))
196 #define	pmd_bad(pmd)		(pmd_val(pmd) & _PMD_BAD)
197 #define	pmd_present(pmd)	(pmd_val(pmd) & _PMD_PRESENT_MASK)
198 static inline void pmd_clear(pmd_t *pmdp)
199 {
200 	*pmdp = __pmd(0);
201 }
202 
203 
204 
205 /*
206  * PTE updates. This function is called whenever an existing
207  * valid PTE is updated. This does -not- include set_pte_at()
208  * which nowadays only sets a new PTE.
209  *
210  * Depending on the type of MMU, we may need to use atomic updates
211  * and the PTE may be either 32 or 64 bit wide. In the later case,
212  * when using atomic updates, only the low part of the PTE is
213  * accessed atomically.
214  *
215  * In addition, on 44x, we also maintain a global flag indicating
216  * that an executable user mapping was modified, which is needed
217  * to properly flush the virtually tagged instruction cache of
218  * those implementations.
219  */
220 #ifndef CONFIG_PTE_64BIT
221 static inline unsigned long pte_update(pte_t *p,
222 				       unsigned long clr,
223 				       unsigned long set)
224 {
225 #ifdef PTE_ATOMIC_UPDATES
226 	unsigned long old, tmp;
227 
228 	__asm__ __volatile__("\
229 1:	lwarx	%0,0,%3\n\
230 	andc	%1,%0,%4\n\
231 	or	%1,%1,%5\n"
232 	PPC405_ERR77(0,%3)
233 "	stwcx.	%1,0,%3\n\
234 	bne-	1b"
235 	: "=&r" (old), "=&r" (tmp), "=m" (*p)
236 	: "r" (p), "r" (clr), "r" (set), "m" (*p)
237 	: "cc" );
238 #else /* PTE_ATOMIC_UPDATES */
239 	unsigned long old = pte_val(*p);
240 	unsigned long new = (old & ~clr) | set;
241 
242 #if defined(CONFIG_PPC_8xx) && defined(CONFIG_PPC_16K_PAGES)
243 	p->pte = p->pte1 = p->pte2 = p->pte3 = new;
244 #else
245 	*p = __pte(new);
246 #endif
247 #endif /* !PTE_ATOMIC_UPDATES */
248 
249 #ifdef CONFIG_44x
250 	if ((old & _PAGE_USER) && (old & _PAGE_EXEC))
251 		icache_44x_need_flush = 1;
252 #endif
253 	return old;
254 }
255 #else /* CONFIG_PTE_64BIT */
256 static inline unsigned long long pte_update(pte_t *p,
257 					    unsigned long clr,
258 					    unsigned long set)
259 {
260 #ifdef PTE_ATOMIC_UPDATES
261 	unsigned long long old;
262 	unsigned long tmp;
263 
264 	__asm__ __volatile__("\
265 1:	lwarx	%L0,0,%4\n\
266 	lwzx	%0,0,%3\n\
267 	andc	%1,%L0,%5\n\
268 	or	%1,%1,%6\n"
269 	PPC405_ERR77(0,%3)
270 "	stwcx.	%1,0,%4\n\
271 	bne-	1b"
272 	: "=&r" (old), "=&r" (tmp), "=m" (*p)
273 	: "r" (p), "r" ((unsigned long)(p) + 4), "r" (clr), "r" (set), "m" (*p)
274 	: "cc" );
275 #else /* PTE_ATOMIC_UPDATES */
276 	unsigned long long old = pte_val(*p);
277 	*p = __pte((old & ~(unsigned long long)clr) | set);
278 #endif /* !PTE_ATOMIC_UPDATES */
279 
280 #ifdef CONFIG_44x
281 	if ((old & _PAGE_USER) && (old & _PAGE_EXEC))
282 		icache_44x_need_flush = 1;
283 #endif
284 	return old;
285 }
286 #endif /* CONFIG_PTE_64BIT */
287 
288 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
289 static inline int __ptep_test_and_clear_young(unsigned int context, unsigned long addr, pte_t *ptep)
290 {
291 	unsigned long old;
292 	old = pte_update(ptep, _PAGE_ACCESSED, 0);
293 	return (old & _PAGE_ACCESSED) != 0;
294 }
295 #define ptep_test_and_clear_young(__vma, __addr, __ptep) \
296 	__ptep_test_and_clear_young((__vma)->vm_mm->context.id, __addr, __ptep)
297 
298 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
299 static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
300 				       pte_t *ptep)
301 {
302 	return __pte(pte_update(ptep, ~0, 0));
303 }
304 
305 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
306 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr,
307 				      pte_t *ptep)
308 {
309 	unsigned long clr = ~pte_val(pte_wrprotect(__pte(~0)));
310 	unsigned long set = pte_val(pte_wrprotect(__pte(0)));
311 
312 	pte_update(ptep, clr, set);
313 }
314 
315 static inline void __ptep_set_access_flags(struct vm_area_struct *vma,
316 					   pte_t *ptep, pte_t entry,
317 					   unsigned long address,
318 					   int psize)
319 {
320 	pte_t pte_set = pte_mkyoung(pte_mkdirty(pte_mkwrite(pte_mkexec(__pte(0)))));
321 	pte_t pte_clr = pte_mkyoung(pte_mkdirty(pte_mkwrite(pte_mkexec(__pte(~0)))));
322 	unsigned long set = pte_val(entry) & pte_val(pte_set);
323 	unsigned long clr = ~pte_val(entry) & ~pte_val(pte_clr);
324 
325 	pte_update(ptep, clr, set);
326 
327 	flush_tlb_page(vma, address);
328 }
329 
330 static inline int pte_young(pte_t pte)
331 {
332 	return pte_val(pte) & _PAGE_ACCESSED;
333 }
334 
335 #define __HAVE_ARCH_PTE_SAME
336 #define pte_same(A,B)	((pte_val(A) ^ pte_val(B)) == 0)
337 
338 /*
339  * Note that on Book E processors, the pmd contains the kernel virtual
340  * (lowmem) address of the pte page.  The physical address is less useful
341  * because everything runs with translation enabled (even the TLB miss
342  * handler).  On everything else the pmd contains the physical address
343  * of the pte page.  -- paulus
344  */
345 #ifndef CONFIG_BOOKE
346 #define pmd_page_vaddr(pmd)	\
347 	((unsigned long)__va(pmd_val(pmd) & ~(PTE_TABLE_SIZE - 1)))
348 #define pmd_page(pmd)		\
349 	pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT)
350 #else
351 #define pmd_page_vaddr(pmd)	\
352 	((unsigned long)(pmd_val(pmd) & ~(PTE_TABLE_SIZE - 1)))
353 #define pmd_page(pmd)		\
354 	pfn_to_page((__pa(pmd_val(pmd)) >> PAGE_SHIFT))
355 #endif
356 
357 /* to find an entry in a kernel page-table-directory */
358 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
359 
360 /* to find an entry in a page-table-directory */
361 #define pgd_index(address)	 ((address) >> PGDIR_SHIFT)
362 #define pgd_offset(mm, address)	 ((mm)->pgd + pgd_index(address))
363 
364 /* Find an entry in the third-level page table.. */
365 #define pte_index(address)		\
366 	(((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
367 #define pte_offset_kernel(dir, addr)	\
368 	(pmd_bad(*(dir)) ? NULL : (pte_t *)pmd_page_vaddr(*(dir)) + \
369 				  pte_index(addr))
370 #define pte_offset_map(dir, addr)		\
371 	((pte_t *)(kmap_atomic(pmd_page(*(dir))) + \
372 		   (pmd_page_vaddr(*(dir)) & ~PAGE_MASK)) + pte_index(addr))
373 #define pte_unmap(pte)		kunmap_atomic(pte)
374 
375 /*
376  * Encode and decode a swap entry.
377  * Note that the bits we use in a PTE for representing a swap entry
378  * must not include the _PAGE_PRESENT bit.
379  *   -- paulus
380  */
381 #define __swp_type(entry)		((entry).val & 0x1f)
382 #define __swp_offset(entry)		((entry).val >> 5)
383 #define __swp_entry(type, offset)	((swp_entry_t) { (type) | ((offset) << 5) })
384 #define __pte_to_swp_entry(pte)		((swp_entry_t) { pte_val(pte) >> 3 })
385 #define __swp_entry_to_pte(x)		((pte_t) { (x).val << 3 })
386 
387 #endif /* !__ASSEMBLY__ */
388 
389 #endif /* __ASM_POWERPC_NOHASH_32_PGTABLE_H */
390