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pgtable_32.h
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1 #ifndef __ASM_SH_PGTABLE_32_H
2 #define __ASM_SH_PGTABLE_32_H
3 
4 /*
5  * Linux PTEL encoding.
6  *
7  * Hardware and software bit definitions for the PTEL value (see below for
8  * notes on SH-X2 MMUs and 64-bit PTEs):
9  *
10  * - Bits 0 and 7 are reserved on SH-3 (_PAGE_WT and _PAGE_SZ1 on SH-4).
11  *
12  * - Bit 1 is the SH-bit, but is unused on SH-3 due to an MMU bug (the
13  * hardware PTEL value can't have the SH-bit set when MMUCR.IX is set,
14  * which is the default in cpu-sh3/mmu_context.h:MMU_CONTROL_INIT).
15  *
16  * In order to keep this relatively clean, do not use these for defining
17  * SH-3 specific flags until all of the other unused bits have been
18  * exhausted.
19  *
20  * - Bit 9 is reserved by everyone and used by _PAGE_PROTNONE.
21  *
22  * - Bits 10 and 11 are low bits of the PPN that are reserved on >= 4K pages.
23  * Bit 10 is used for _PAGE_ACCESSED, and bit 11 is used for _PAGE_SPECIAL.
24  *
25  * - On 29 bit platforms, bits 31 to 29 are used for the space attributes
26  * and timing control which (together with bit 0) are moved into the
27  * old-style PTEA on the parts that support it.
28  *
29  * XXX: Leave the _PAGE_FILE and _PAGE_WT overhaul for a rainy day.
30  *
31  * SH-X2 MMUs and extended PTEs
32  *
33  * SH-X2 supports an extended mode TLB with split data arrays due to the
34  * number of bits needed for PR and SZ (now EPR and ESZ) encodings. The PR and
35  * SZ bit placeholders still exist in data array 1, but are implemented as
36  * reserved bits, with the real logic existing in data array 2.
37  *
38  * The downside to this is that we can no longer fit everything in to a 32-bit
39  * PTE encoding, so a 64-bit pte_t is necessary for these parts. On the plus
40  * side, this gives us quite a few spare bits to play with for future usage.
41  */
42 /* Legacy and compat mode bits */
43 #define _PAGE_WT 0x001 /* WT-bit on SH-4, 0 on SH-3 */
44 #define _PAGE_HW_SHARED 0x002 /* SH-bit : shared among processes */
45 #define _PAGE_DIRTY 0x004 /* D-bit : page changed */
46 #define _PAGE_CACHABLE 0x008 /* C-bit : cachable */
47 #define _PAGE_SZ0 0x010 /* SZ0-bit : Size of page */
48 #define _PAGE_RW 0x020 /* PR0-bit : write access allowed */
49 #define _PAGE_USER 0x040 /* PR1-bit : user space access allowed*/
50 #define _PAGE_SZ1 0x080 /* SZ1-bit : Size of page (on SH-4) */
51 #define _PAGE_PRESENT 0x100 /* V-bit : page is valid */
52 #define _PAGE_PROTNONE 0x200 /* software: if not present */
53 #define _PAGE_ACCESSED 0x400 /* software: page referenced */
54 #define _PAGE_FILE _PAGE_WT /* software: pagecache or swap? */
55 #define _PAGE_SPECIAL 0x800 /* software: special page */
56 
57 #define _PAGE_SZ_MASK (_PAGE_SZ0 | _PAGE_SZ1)
58 #define _PAGE_PR_MASK (_PAGE_RW | _PAGE_USER)
59 
60 /* Extended mode bits */
61 #define _PAGE_EXT_ESZ0 0x0010 /* ESZ0-bit: Size of page */
62 #define _PAGE_EXT_ESZ1 0x0020 /* ESZ1-bit: Size of page */
63 #define _PAGE_EXT_ESZ2 0x0040 /* ESZ2-bit: Size of page */
64 #define _PAGE_EXT_ESZ3 0x0080 /* ESZ3-bit: Size of page */
65 
66 #define _PAGE_EXT_USER_EXEC 0x0100 /* EPR0-bit: User space executable */
67 #define _PAGE_EXT_USER_WRITE 0x0200 /* EPR1-bit: User space writable */
68 #define _PAGE_EXT_USER_READ 0x0400 /* EPR2-bit: User space readable */
69 
70 #define _PAGE_EXT_KERN_EXEC 0x0800 /* EPR3-bit: Kernel space executable */
71 #define _PAGE_EXT_KERN_WRITE 0x1000 /* EPR4-bit: Kernel space writable */
72 #define _PAGE_EXT_KERN_READ 0x2000 /* EPR5-bit: Kernel space readable */
73 
74 #define _PAGE_EXT_WIRED 0x4000 /* software: Wire TLB entry */
75 
76 /* Wrapper for extended mode pgprot twiddling */
77 #define _PAGE_EXT(x) ((unsigned long long)(x) << 32)
78 
79 #ifdef CONFIG_X2TLB
80 #define _PAGE_PCC_MASK 0x00000000 /* No legacy PTEA support */
81 #else
82 
83 /* software: moves to PTEA.TC (Timing Control) */
84 #define _PAGE_PCC_AREA5 0x00000000 /* use BSC registers for area5 */
85 #define _PAGE_PCC_AREA6 0x80000000 /* use BSC registers for area6 */
86 
87 /* software: moves to PTEA.SA[2:0] (Space Attributes) */
88 #define _PAGE_PCC_IODYN 0x00000001 /* IO space, dynamically sized bus */
89 #define _PAGE_PCC_IO8 0x20000000 /* IO space, 8 bit bus */
90 #define _PAGE_PCC_IO16 0x20000001 /* IO space, 16 bit bus */
91 #define _PAGE_PCC_COM8 0x40000000 /* Common Memory space, 8 bit bus */
92 #define _PAGE_PCC_COM16 0x40000001 /* Common Memory space, 16 bit bus */
93 #define _PAGE_PCC_ATR8 0x60000000 /* Attribute Memory space, 8 bit bus */
94 #define _PAGE_PCC_ATR16 0x60000001 /* Attribute Memory space, 6 bit bus */
95 
96 #define _PAGE_PCC_MASK 0xe0000001
97 
98 /* copy the ptea attributes */
99 static inline unsigned long copy_ptea_attributes(unsigned long x)
100 {
101  return ((x >> 28) & 0xe) | (x & 0x1);
102 }
103 #endif
104 
105 /* Mask which drops unused bits from the PTEL value */
106 #if defined(CONFIG_CPU_SH3)
107 #define _PAGE_CLEAR_FLAGS (_PAGE_PROTNONE | _PAGE_ACCESSED| \
108  _PAGE_FILE | _PAGE_SZ1 | \
109  _PAGE_HW_SHARED)
110 #elif defined(CONFIG_X2TLB)
111 /* Get rid of the legacy PR/SZ bits when using extended mode */
112 #define _PAGE_CLEAR_FLAGS (_PAGE_PROTNONE | _PAGE_ACCESSED | \
113  _PAGE_FILE | _PAGE_PR_MASK | _PAGE_SZ_MASK)
114 #else
115 #define _PAGE_CLEAR_FLAGS (_PAGE_PROTNONE | _PAGE_ACCESSED | _PAGE_FILE)
116 #endif
117 
118 #define _PAGE_FLAGS_HARDWARE_MASK (phys_addr_mask() & ~(_PAGE_CLEAR_FLAGS))
119 
120 /* Hardware flags, page size encoding */
121 #if !defined(CONFIG_MMU)
122 # define _PAGE_FLAGS_HARD 0ULL
123 #elif defined(CONFIG_X2TLB)
124 # if defined(CONFIG_PAGE_SIZE_4KB)
125 # define _PAGE_FLAGS_HARD _PAGE_EXT(_PAGE_EXT_ESZ0)
126 # elif defined(CONFIG_PAGE_SIZE_8KB)
127 # define _PAGE_FLAGS_HARD _PAGE_EXT(_PAGE_EXT_ESZ1)
128 # elif defined(CONFIG_PAGE_SIZE_64KB)
129 # define _PAGE_FLAGS_HARD _PAGE_EXT(_PAGE_EXT_ESZ2)
130 # endif
131 #else
132 # if defined(CONFIG_PAGE_SIZE_4KB)
133 # define _PAGE_FLAGS_HARD _PAGE_SZ0
134 # elif defined(CONFIG_PAGE_SIZE_64KB)
135 # define _PAGE_FLAGS_HARD _PAGE_SZ1
136 # endif
137 #endif
138 
139 #if defined(CONFIG_X2TLB)
140 # if defined(CONFIG_HUGETLB_PAGE_SIZE_64K)
141 # define _PAGE_SZHUGE (_PAGE_EXT_ESZ2)
142 # elif defined(CONFIG_HUGETLB_PAGE_SIZE_256K)
143 # define _PAGE_SZHUGE (_PAGE_EXT_ESZ0 | _PAGE_EXT_ESZ2)
144 # elif defined(CONFIG_HUGETLB_PAGE_SIZE_1MB)
145 # define _PAGE_SZHUGE (_PAGE_EXT_ESZ0 | _PAGE_EXT_ESZ1 | _PAGE_EXT_ESZ2)
146 # elif defined(CONFIG_HUGETLB_PAGE_SIZE_4MB)
147 # define _PAGE_SZHUGE (_PAGE_EXT_ESZ3)
148 # elif defined(CONFIG_HUGETLB_PAGE_SIZE_64MB)
149 # define _PAGE_SZHUGE (_PAGE_EXT_ESZ2 | _PAGE_EXT_ESZ3)
150 # endif
151 # define _PAGE_WIRED (_PAGE_EXT(_PAGE_EXT_WIRED))
152 #else
153 # if defined(CONFIG_HUGETLB_PAGE_SIZE_64K)
154 # define _PAGE_SZHUGE (_PAGE_SZ1)
155 # elif defined(CONFIG_HUGETLB_PAGE_SIZE_1MB)
156 # define _PAGE_SZHUGE (_PAGE_SZ0 | _PAGE_SZ1)
157 # endif
158 # define _PAGE_WIRED (0)
159 #endif
160 
161 /*
162  * Stub out _PAGE_SZHUGE if we don't have a good definition for it,
163  * to make pte_mkhuge() happy.
164  */
165 #ifndef _PAGE_SZHUGE
166 # define _PAGE_SZHUGE (_PAGE_FLAGS_HARD)
167 #endif
168 
169 /*
170  * Mask of bits that are to be preserved across pgprot changes.
171  */
172 #define _PAGE_CHG_MASK \
173  (PTE_MASK | _PAGE_ACCESSED | _PAGE_CACHABLE | \
174  _PAGE_DIRTY | _PAGE_SPECIAL)
175 
176 #ifndef __ASSEMBLY__
177 
178 #if defined(CONFIG_X2TLB) /* SH-X2 TLB */
179 #define PAGE_NONE __pgprot(_PAGE_PROTNONE | _PAGE_CACHABLE | \
180  _PAGE_ACCESSED | _PAGE_FLAGS_HARD)
181 
182 #define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED | \
183  _PAGE_CACHABLE | _PAGE_FLAGS_HARD | \
184  _PAGE_EXT(_PAGE_EXT_KERN_READ | \
185  _PAGE_EXT_KERN_WRITE | \
186  _PAGE_EXT_USER_READ | \
187  _PAGE_EXT_USER_WRITE))
188 
189 #define PAGE_EXECREAD __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED | \
190  _PAGE_CACHABLE | _PAGE_FLAGS_HARD | \
191  _PAGE_EXT(_PAGE_EXT_KERN_EXEC | \
192  _PAGE_EXT_KERN_READ | \
193  _PAGE_EXT_USER_EXEC | \
194  _PAGE_EXT_USER_READ))
195 
196 #define PAGE_COPY PAGE_EXECREAD
197 
198 #define PAGE_READONLY __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED | \
199  _PAGE_CACHABLE | _PAGE_FLAGS_HARD | \
200  _PAGE_EXT(_PAGE_EXT_KERN_READ | \
201  _PAGE_EXT_USER_READ))
202 
203 #define PAGE_WRITEONLY __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED | \
204  _PAGE_CACHABLE | _PAGE_FLAGS_HARD | \
205  _PAGE_EXT(_PAGE_EXT_KERN_WRITE | \
206  _PAGE_EXT_USER_WRITE))
207 
208 #define PAGE_RWX __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED | \
209  _PAGE_CACHABLE | _PAGE_FLAGS_HARD | \
210  _PAGE_EXT(_PAGE_EXT_KERN_WRITE | \
211  _PAGE_EXT_KERN_READ | \
212  _PAGE_EXT_KERN_EXEC | \
213  _PAGE_EXT_USER_WRITE | \
214  _PAGE_EXT_USER_READ | \
215  _PAGE_EXT_USER_EXEC))
216 
217 #define PAGE_KERNEL __pgprot(_PAGE_PRESENT | _PAGE_CACHABLE | \
218  _PAGE_DIRTY | _PAGE_ACCESSED | \
219  _PAGE_HW_SHARED | _PAGE_FLAGS_HARD | \
220  _PAGE_EXT(_PAGE_EXT_KERN_READ | \
221  _PAGE_EXT_KERN_WRITE | \
222  _PAGE_EXT_KERN_EXEC))
223 
224 #define PAGE_KERNEL_NOCACHE \
225  __pgprot(_PAGE_PRESENT | _PAGE_DIRTY | \
226  _PAGE_ACCESSED | _PAGE_HW_SHARED | \
227  _PAGE_FLAGS_HARD | \
228  _PAGE_EXT(_PAGE_EXT_KERN_READ | \
229  _PAGE_EXT_KERN_WRITE | \
230  _PAGE_EXT_KERN_EXEC))
231 
232 #define PAGE_KERNEL_RO __pgprot(_PAGE_PRESENT | _PAGE_CACHABLE | \
233  _PAGE_DIRTY | _PAGE_ACCESSED | \
234  _PAGE_HW_SHARED | _PAGE_FLAGS_HARD | \
235  _PAGE_EXT(_PAGE_EXT_KERN_READ | \
236  _PAGE_EXT_KERN_EXEC))
237 
238 #define PAGE_KERNEL_PCC(slot, type) \
239  __pgprot(0)
240 
241 #elif defined(CONFIG_MMU) /* SH-X TLB */
242 #define PAGE_NONE __pgprot(_PAGE_PROTNONE | _PAGE_CACHABLE | \
243  _PAGE_ACCESSED | _PAGE_FLAGS_HARD)
244 
245 #define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | \
246  _PAGE_CACHABLE | _PAGE_ACCESSED | \
247  _PAGE_FLAGS_HARD)
248 
249 #define PAGE_COPY __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_CACHABLE | \
250  _PAGE_ACCESSED | _PAGE_FLAGS_HARD)
251 
252 #define PAGE_READONLY __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_CACHABLE | \
253  _PAGE_ACCESSED | _PAGE_FLAGS_HARD)
254 
255 #define PAGE_EXECREAD PAGE_READONLY
256 #define PAGE_RWX PAGE_SHARED
257 #define PAGE_WRITEONLY PAGE_SHARED
258 
259 #define PAGE_KERNEL __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_CACHABLE | \
260  _PAGE_DIRTY | _PAGE_ACCESSED | \
261  _PAGE_HW_SHARED | _PAGE_FLAGS_HARD)
262 
263 #define PAGE_KERNEL_NOCACHE \
264  __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | \
265  _PAGE_ACCESSED | _PAGE_HW_SHARED | \
266  _PAGE_FLAGS_HARD)
267 
268 #define PAGE_KERNEL_RO __pgprot(_PAGE_PRESENT | _PAGE_CACHABLE | \
269  _PAGE_DIRTY | _PAGE_ACCESSED | \
270  _PAGE_HW_SHARED | _PAGE_FLAGS_HARD)
271 
272 #define PAGE_KERNEL_PCC(slot, type) \
273  __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | \
274  _PAGE_ACCESSED | _PAGE_FLAGS_HARD | \
275  (slot ? _PAGE_PCC_AREA5 : _PAGE_PCC_AREA6) | \
276  (type))
277 #else /* no mmu */
278 #define PAGE_NONE __pgprot(0)
279 #define PAGE_SHARED __pgprot(0)
280 #define PAGE_COPY __pgprot(0)
281 #define PAGE_EXECREAD __pgprot(0)
282 #define PAGE_RWX __pgprot(0)
283 #define PAGE_READONLY __pgprot(0)
284 #define PAGE_WRITEONLY __pgprot(0)
285 #define PAGE_KERNEL __pgprot(0)
286 #define PAGE_KERNEL_NOCACHE __pgprot(0)
287 #define PAGE_KERNEL_RO __pgprot(0)
288 
289 #define PAGE_KERNEL_PCC(slot, type) \
290  __pgprot(0)
291 #endif
292 
293 #endif /* __ASSEMBLY__ */
294 
295 #ifndef __ASSEMBLY__
296 
297 /*
298  * Certain architectures need to do special things when PTEs
299  * within a page table are directly modified. Thus, the following
300  * hook is made available.
301  */
302 #ifdef CONFIG_X2TLB
303 static inline void set_pte(pte_t *ptep, pte_t pte)
304 {
305  ptep->pte_high = pte.pte_high;
306  smp_wmb();
307  ptep->pte_low = pte.pte_low;
308 }
309 #else
310 #define set_pte(pteptr, pteval) (*(pteptr) = pteval)
311 #endif
312 
313 #define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
314 
315 /*
316  * (pmds are folded into pgds so this doesn't get actually called,
317  * but the define is needed for a generic inline function.)
318  */
319 #define set_pmd(pmdptr, pmdval) (*(pmdptr) = pmdval)
320 
321 #define pfn_pte(pfn, prot) \
322  __pte(((unsigned long long)(pfn) << PAGE_SHIFT) | pgprot_val(prot))
323 #define pfn_pmd(pfn, prot) \
324  __pmd(((unsigned long long)(pfn) << PAGE_SHIFT) | pgprot_val(prot))
325 
326 #define pte_none(x) (!pte_val(x))
327 #define pte_present(x) ((x).pte_low & (_PAGE_PRESENT | _PAGE_PROTNONE))
328 
329 #define pte_clear(mm,addr,xp) do { set_pte_at(mm, addr, xp, __pte(0)); } while (0)
330 
331 #define pmd_none(x) (!pmd_val(x))
332 #define pmd_present(x) (pmd_val(x))
333 #define pmd_clear(xp) do { set_pmd(xp, __pmd(0)); } while (0)
334 #define pmd_bad(x) (pmd_val(x) & ~PAGE_MASK)
335 
336 #define pages_to_mb(x) ((x) >> (20-PAGE_SHIFT))
337 #define pte_page(x) pfn_to_page(pte_pfn(x))
338 
339 /*
340  * The following only work if pte_present() is true.
341  * Undefined behaviour if not..
342  */
343 #define pte_not_present(pte) (!((pte).pte_low & _PAGE_PRESENT))
344 #define pte_dirty(pte) ((pte).pte_low & _PAGE_DIRTY)
345 #define pte_young(pte) ((pte).pte_low & _PAGE_ACCESSED)
346 #define pte_file(pte) ((pte).pte_low & _PAGE_FILE)
347 #define pte_special(pte) ((pte).pte_low & _PAGE_SPECIAL)
348 
349 #ifdef CONFIG_X2TLB
350 #define pte_write(pte) \
351  ((pte).pte_high & (_PAGE_EXT_USER_WRITE | _PAGE_EXT_KERN_WRITE))
352 #else
353 #define pte_write(pte) ((pte).pte_low & _PAGE_RW)
354 #endif
355 
356 #define PTE_BIT_FUNC(h,fn,op) \
357 static inline pte_t pte_##fn(pte_t pte) { pte.pte_##h op; return pte; }
358 
359 #ifdef CONFIG_X2TLB
360 /*
361  * We cheat a bit in the SH-X2 TLB case. As the permission bits are
362  * individually toggled (and user permissions are entirely decoupled from
363  * kernel permissions), we attempt to couple them a bit more sanely here.
364  */
365 PTE_BIT_FUNC(high, wrprotect, &= ~(_PAGE_EXT_USER_WRITE | _PAGE_EXT_KERN_WRITE));
366 PTE_BIT_FUNC(high, mkwrite, |= _PAGE_EXT_USER_WRITE | _PAGE_EXT_KERN_WRITE);
367 PTE_BIT_FUNC(high, mkhuge, |= _PAGE_SZHUGE);
368 #else
369 PTE_BIT_FUNC(low, wrprotect, &= ~_PAGE_RW);
370 PTE_BIT_FUNC(low, mkwrite, |= _PAGE_RW);
371 PTE_BIT_FUNC(low, mkhuge, |= _PAGE_SZHUGE);
372 #endif
373 
374 PTE_BIT_FUNC(low, mkclean, &= ~_PAGE_DIRTY);
375 PTE_BIT_FUNC(low, mkdirty, |= _PAGE_DIRTY);
376 PTE_BIT_FUNC(low, mkold, &= ~_PAGE_ACCESSED);
377 PTE_BIT_FUNC(low, mkyoung, |= _PAGE_ACCESSED);
378 PTE_BIT_FUNC(low, mkspecial, |= _PAGE_SPECIAL);
379 
380 /*
381  * Macro and implementation to make a page protection as uncachable.
382  */
383 #define pgprot_writecombine(prot) \
384  __pgprot(pgprot_val(prot) & ~_PAGE_CACHABLE)
385 
386 #define pgprot_noncached pgprot_writecombine
387 
388 /*
389  * Conversion functions: convert a page and protection to a page entry,
390  * and a page entry and page directory to the page they refer to.
391  *
392  * extern pte_t mk_pte(struct page *page, pgprot_t pgprot)
393  */
394 #define mk_pte(page, pgprot) pfn_pte(page_to_pfn(page), (pgprot))
395 
396 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
397 {
398  pte.pte_low &= _PAGE_CHG_MASK;
399  pte.pte_low |= pgprot_val(newprot);
400 
401 #ifdef CONFIG_X2TLB
402  pte.pte_high |= pgprot_val(newprot) >> 32;
403 #endif
404 
405  return pte;
406 }
407 
408 #define pmd_page_vaddr(pmd) ((unsigned long)pmd_val(pmd))
409 #define pmd_page(pmd) (virt_to_page(pmd_val(pmd)))
410 
411 /* to find an entry in a page-table-directory. */
412 #define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
413 #define pgd_offset(mm, address) ((mm)->pgd + pgd_index(address))
414 #define __pgd_offset(address) pgd_index(address)
415 
416 /* to find an entry in a kernel page-table-directory */
417 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
418 
419 #define __pud_offset(address) (((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
420 #define __pmd_offset(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
421 
422 /* Find an entry in the third-level page table.. */
423 #define pte_index(address) ((address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
424 #define __pte_offset(address) pte_index(address)
425 
426 #define pte_offset_kernel(dir, address) \
427  ((pte_t *) pmd_page_vaddr(*(dir)) + pte_index(address))
428 #define pte_offset_map(dir, address) pte_offset_kernel(dir, address)
429 #define pte_unmap(pte) do { } while (0)
430 
431 #ifdef CONFIG_X2TLB
432 #define pte_ERROR(e) \
433  printk("%s:%d: bad pte %p(%08lx%08lx).\n", __FILE__, __LINE__, \
434  &(e), (e).pte_high, (e).pte_low)
435 #define pgd_ERROR(e) \
436  printk("%s:%d: bad pgd %016llx.\n", __FILE__, __LINE__, pgd_val(e))
437 #else
438 #define pte_ERROR(e) \
439  printk("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, pte_val(e))
440 #define pgd_ERROR(e) \
441  printk("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))
442 #endif
443 
444 /*
445  * Encode and de-code a swap entry
446  *
447  * Constraints:
448  * _PAGE_FILE at bit 0
449  * _PAGE_PRESENT at bit 8
450  * _PAGE_PROTNONE at bit 9
451  *
452  * For the normal case, we encode the swap type into bits 0:7 and the
453  * swap offset into bits 10:30. For the 64-bit PTE case, we keep the
454  * preserved bits in the low 32-bits and use the upper 32 as the swap
455  * offset (along with a 5-bit type), following the same approach as x86
456  * PAE. This keeps the logic quite simple, and allows for a full 32
457  * PTE_FILE_MAX_BITS, as opposed to the 29-bits we're constrained with
458  * in the pte_low case.
459  *
460  * As is evident by the Alpha code, if we ever get a 64-bit unsigned
461  * long (swp_entry_t) to match up with the 64-bit PTEs, this all becomes
462  * much cleaner..
463  *
464  * NOTE: We should set ZEROs at the position of _PAGE_PRESENT
465  * and _PAGE_PROTNONE bits
466  */
467 #ifdef CONFIG_X2TLB
468 #define __swp_type(x) ((x).val & 0x1f)
469 #define __swp_offset(x) ((x).val >> 5)
470 #define __swp_entry(type, offset) ((swp_entry_t){ (type) | (offset) << 5})
471 #define __pte_to_swp_entry(pte) ((swp_entry_t){ (pte).pte_high })
472 #define __swp_entry_to_pte(x) ((pte_t){ 0, (x).val })
473 
474 /*
475  * Encode and decode a nonlinear file mapping entry
476  */
477 #define pte_to_pgoff(pte) ((pte).pte_high)
478 #define pgoff_to_pte(off) ((pte_t) { _PAGE_FILE, (off) })
479 
480 #define PTE_FILE_MAX_BITS 32
481 #else
482 #define __swp_type(x) ((x).val & 0xff)
483 #define __swp_offset(x) ((x).val >> 10)
484 #define __swp_entry(type, offset) ((swp_entry_t){(type) | (offset) <<10})
485 
486 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) >> 1 })
487 #define __swp_entry_to_pte(x) ((pte_t) { (x).val << 1 })
488 
489 /*
490  * Encode and decode a nonlinear file mapping entry
491  */
492 #define PTE_FILE_MAX_BITS 29
493 #define pte_to_pgoff(pte) (pte_val(pte) >> 1)
494 #define pgoff_to_pte(off) ((pte_t) { ((off) << 1) | _PAGE_FILE })
495 #endif
496 
497 #endif /* __ASSEMBLY__ */
498 #endif /* __ASM_SH_PGTABLE_32_H */
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