1/* pgtable.h: FR-V page table mangling
2 *
3 * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 *
11 * Derived from:
12 *	include/asm-m68knommu/pgtable.h
13 *	include/asm-i386/pgtable.h
14 */
15
16#ifndef _ASM_PGTABLE_H
17#define _ASM_PGTABLE_H
18
19#include <asm/mem-layout.h>
20#include <asm/setup.h>
21#include <asm/processor.h>
22
23#ifndef __ASSEMBLY__
24#include <linux/threads.h>
25#include <linux/slab.h>
26#include <linux/list.h>
27#include <linux/spinlock.h>
28#include <linux/sched.h>
29struct vm_area_struct;
30#endif
31
32#ifndef __ASSEMBLY__
33#if defined(CONFIG_HIGHPTE)
34typedef unsigned long pte_addr_t;
35#else
36typedef pte_t *pte_addr_t;
37#endif
38#endif
39
40/*****************************************************************************/
41/*
42 * MMU-less operation case first
43 */
44#ifndef CONFIG_MMU
45
46#define pgd_present(pgd)	(1)		/* pages are always present on NO_MM */
47#define pgd_none(pgd)		(0)
48#define pgd_bad(pgd)		(0)
49#define pgd_clear(pgdp)
50#define kern_addr_valid(addr)	(1)
51#define	pmd_offset(a, b)	((void *) 0)
52
53#define PAGE_NONE		__pgprot(0)	/* these mean nothing to NO_MM */
54#define PAGE_SHARED		__pgprot(0)	/* these mean nothing to NO_MM */
55#define PAGE_COPY		__pgprot(0)	/* these mean nothing to NO_MM */
56#define PAGE_READONLY		__pgprot(0)	/* these mean nothing to NO_MM */
57#define PAGE_KERNEL		__pgprot(0)	/* these mean nothing to NO_MM */
58
59#define __swp_type(x)		(0)
60#define __swp_offset(x)		(0)
61#define __swp_entry(typ,off)	((swp_entry_t) { ((typ) | ((off) << 7)) })
62#define __pte_to_swp_entry(pte)	((swp_entry_t) { pte_val(pte) })
63#define __swp_entry_to_pte(x)	((pte_t) { (x).val })
64
65#define ZERO_PAGE(vaddr)	({ BUG(); NULL; })
66
67#define swapper_pg_dir		((pgd_t *) NULL)
68
69#define pgtable_cache_init()		do {} while (0)
70
71#include <asm-generic/pgtable.h>
72
73#else /* !CONFIG_MMU */
74/*****************************************************************************/
75/*
76 * then MMU operation
77 */
78
79/*
80 * ZERO_PAGE is a global shared page that is always zero: used
81 * for zero-mapped memory areas etc..
82 */
83#ifndef __ASSEMBLY__
84extern unsigned long empty_zero_page;
85#define ZERO_PAGE(vaddr)	virt_to_page(empty_zero_page)
86#endif
87
88/*
89 * we use 2-level page tables, folding the PMD (mid-level table) into the PGE (top-level entry)
90 * [see Documentation/frv/mmu-layout.txt]
91 *
92 * Page Directory:
93 *  - Size: 16KB
94 *  - 64 PGEs per PGD
95 *  - Each PGE holds 1 PUD and covers 64MB
96 *
97 * Page Upper Directory:
98 *  - Size: 256B
99 *  - 1 PUE per PUD
100 *  - Each PUE holds 1 PMD and covers 64MB
101 *
102 * Page Mid-Level Directory
103 *  - Size: 256B
104 *  - 1 PME per PMD
105 *  - Each PME holds 64 STEs, all of which point to separate chunks of the same Page Table
106 *  - All STEs are instantiated at the same time
107 *
108 * Page Table
109 *  - Size: 16KB
110 *  - 4096 PTEs per PT
111 *  - Each Linux PT is subdivided into 64 FR451 PT's, each of which holds 64 entries
112 *
113 * Pages
114 *  - Size: 4KB
115 *
116 * total PTEs
117 *	= 1 PML4E * 64 PGEs * 1 PUEs * 1 PMEs * 4096 PTEs
118 *	= 1 PML4E * 64 PGEs * 64 STEs * 64 PTEs/FR451-PT
119 *	= 262144 (or 256 * 1024)
120 */
121#define PGDIR_SHIFT		26
122#define PGDIR_SIZE		(1UL << PGDIR_SHIFT)
123#define PGDIR_MASK		(~(PGDIR_SIZE - 1))
124#define PTRS_PER_PGD		64
125
126#define __PAGETABLE_PUD_FOLDED
127#define PUD_SHIFT		26
128#define PTRS_PER_PUD		1
129#define PUD_SIZE		(1UL << PUD_SHIFT)
130#define PUD_MASK		(~(PUD_SIZE - 1))
131#define PUE_SIZE		256
132
133#define __PAGETABLE_PMD_FOLDED
134#define PMD_SHIFT		26
135#define PMD_SIZE		(1UL << PMD_SHIFT)
136#define PMD_MASK		(~(PMD_SIZE - 1))
137#define PTRS_PER_PMD		1
138#define PME_SIZE		256
139
140#define __frv_PT_SIZE		256
141
142#define PTRS_PER_PTE		4096
143
144#define USER_PGDS_IN_LAST_PML4	(TASK_SIZE / PGDIR_SIZE)
145#define FIRST_USER_ADDRESS	0UL
146
147#define USER_PGD_PTRS		(PAGE_OFFSET >> PGDIR_SHIFT)
148#define KERNEL_PGD_PTRS		(PTRS_PER_PGD - USER_PGD_PTRS)
149
150#define TWOLEVEL_PGDIR_SHIFT	26
151#define BOOT_USER_PGD_PTRS	(__PAGE_OFFSET >> TWOLEVEL_PGDIR_SHIFT)
152#define BOOT_KERNEL_PGD_PTRS	(PTRS_PER_PGD - BOOT_USER_PGD_PTRS)
153
154#ifndef __ASSEMBLY__
155
156extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
157
158#define pte_ERROR(e) \
159	printk("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, (e).pte)
160#define pmd_ERROR(e) \
161	printk("%s:%d: bad pmd %08lx.\n", __FILE__, __LINE__, pmd_val(e))
162#define pud_ERROR(e) \
163	printk("%s:%d: bad pud %08lx.\n", __FILE__, __LINE__, pmd_val(pud_val(e)))
164#define pgd_ERROR(e) \
165	printk("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pmd_val(pud_val(pgd_val(e))))
166
167/*
168 * Certain architectures need to do special things when PTEs
169 * within a page table are directly modified.  Thus, the following
170 * hook is made available.
171 */
172#define set_pte(pteptr, pteval)				\
173do {							\
174	*(pteptr) = (pteval);				\
175	asm volatile("dcf %M0" :: "U"(*pteptr));	\
176} while(0)
177#define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
178
179/*
180 * pgd_offset() returns a (pgd_t *)
181 * pgd_index() is used get the offset into the pgd page's array of pgd_t's;
182 */
183#define pgd_offset(mm, address) ((mm)->pgd + pgd_index(address))
184
185/*
186 * a shortcut which implies the use of the kernel's pgd, instead
187 * of a process's
188 */
189#define pgd_offset_k(address) pgd_offset(&init_mm, address)
190
191/*
192 * The "pgd_xxx()" functions here are trivial for a folded two-level
193 * setup: the pud is never bad, and a pud always exists (as it's folded
194 * into the pgd entry)
195 */
196static inline int pgd_none(pgd_t pgd)		{ return 0; }
197static inline int pgd_bad(pgd_t pgd)		{ return 0; }
198static inline int pgd_present(pgd_t pgd)	{ return 1; }
199static inline void pgd_clear(pgd_t *pgd)	{ }
200
201#define pgd_populate(mm, pgd, pud)		do { } while (0)
202/*
203 * (puds are folded into pgds so this doesn't get actually called,
204 * but the define is needed for a generic inline function.)
205 */
206#define set_pgd(pgdptr, pgdval)				\
207do {							\
208	memcpy((pgdptr), &(pgdval), sizeof(pgd_t));	\
209	asm volatile("dcf %M0" :: "U"(*(pgdptr)));	\
210} while(0)
211
212static inline pud_t *pud_offset(pgd_t *pgd, unsigned long address)
213{
214	return (pud_t *) pgd;
215}
216
217#define pgd_page(pgd)				(pud_page((pud_t){ pgd }))
218#define pgd_page_vaddr(pgd)			(pud_page_vaddr((pud_t){ pgd }))
219
220/*
221 * allocating and freeing a pud is trivial: the 1-entry pud is
222 * inside the pgd, so has no extra memory associated with it.
223 */
224#define pud_alloc_one(mm, address)		NULL
225#define pud_free(mm, x)				do { } while (0)
226#define __pud_free_tlb(tlb, x, address)		do { } while (0)
227
228/*
229 * The "pud_xxx()" functions here are trivial for a folded two-level
230 * setup: the pmd is never bad, and a pmd always exists (as it's folded
231 * into the pud entry)
232 */
233static inline int pud_none(pud_t pud)		{ return 0; }
234static inline int pud_bad(pud_t pud)		{ return 0; }
235static inline int pud_present(pud_t pud)	{ return 1; }
236static inline void pud_clear(pud_t *pud)	{ }
237
238#define pud_populate(mm, pmd, pte)		do { } while (0)
239
240/*
241 * (pmds are folded into puds so this doesn't get actually called,
242 * but the define is needed for a generic inline function.)
243 */
244#define set_pud(pudptr, pudval)			set_pmd((pmd_t *)(pudptr), (pmd_t) { pudval })
245
246#define pud_page(pud)				(pmd_page((pmd_t){ pud }))
247#define pud_page_vaddr(pud)			(pmd_page_vaddr((pmd_t){ pud }))
248
249/*
250 * (pmds are folded into pgds so this doesn't get actually called,
251 * but the define is needed for a generic inline function.)
252 */
253extern void __set_pmd(pmd_t *pmdptr, unsigned long __pmd);
254
255#define set_pmd(pmdptr, pmdval)			\
256do {						\
257	__set_pmd((pmdptr), (pmdval).ste[0]);	\
258} while(0)
259
260#define __pmd_index(address)			0
261
262static inline pmd_t *pmd_offset(pud_t *dir, unsigned long address)
263{
264	return (pmd_t *) dir + __pmd_index(address);
265}
266
267#define pte_same(a, b)		((a).pte == (b).pte)
268#define pte_page(x)		(mem_map + ((unsigned long)(((x).pte >> PAGE_SHIFT))))
269#define pte_none(x)		(!(x).pte)
270#define pte_pfn(x)		((unsigned long)(((x).pte >> PAGE_SHIFT)))
271#define pfn_pte(pfn, prot)	__pte(((pfn) << PAGE_SHIFT) | pgprot_val(prot))
272#define pfn_pmd(pfn, prot)	__pmd(((pfn) << PAGE_SHIFT) | pgprot_val(prot))
273
274#define VMALLOC_VMADDR(x)	((unsigned long) (x))
275
276#endif /* !__ASSEMBLY__ */
277
278/*
279 * control flags in AMPR registers and TLB entries
280 */
281#define _PAGE_BIT_PRESENT	xAMPRx_V_BIT
282#define _PAGE_BIT_WP		DAMPRx_WP_BIT
283#define _PAGE_BIT_NOCACHE	xAMPRx_C_BIT
284#define _PAGE_BIT_SUPER		xAMPRx_S_BIT
285#define _PAGE_BIT_ACCESSED	xAMPRx_RESERVED8_BIT
286#define _PAGE_BIT_DIRTY		xAMPRx_M_BIT
287#define _PAGE_BIT_NOTGLOBAL	xAMPRx_NG_BIT
288
289#define _PAGE_PRESENT		xAMPRx_V
290#define _PAGE_WP		DAMPRx_WP
291#define _PAGE_NOCACHE		xAMPRx_C
292#define _PAGE_SUPER		xAMPRx_S
293#define _PAGE_ACCESSED		xAMPRx_RESERVED8	/* accessed if set */
294#define _PAGE_DIRTY		xAMPRx_M
295#define _PAGE_NOTGLOBAL		xAMPRx_NG
296
297#define _PAGE_RESERVED_MASK	(xAMPRx_RESERVED8 | xAMPRx_RESERVED13)
298
299#define _PAGE_PROTNONE		0x000	/* If not present */
300
301#define _PAGE_CHG_MASK		(PTE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
302
303#define __PGPROT_BASE \
304	(_PAGE_PRESENT | xAMPRx_SS_16Kb | xAMPRx_D | _PAGE_NOTGLOBAL | _PAGE_ACCESSED)
305
306#define PAGE_NONE	__pgprot(_PAGE_PROTNONE | _PAGE_ACCESSED)
307#define PAGE_SHARED	__pgprot(__PGPROT_BASE)
308#define PAGE_COPY	__pgprot(__PGPROT_BASE | _PAGE_WP)
309#define PAGE_READONLY	__pgprot(__PGPROT_BASE | _PAGE_WP)
310
311#define __PAGE_KERNEL		(__PGPROT_BASE | _PAGE_SUPER | _PAGE_DIRTY)
312#define __PAGE_KERNEL_NOCACHE	(__PGPROT_BASE | _PAGE_SUPER | _PAGE_DIRTY | _PAGE_NOCACHE)
313#define __PAGE_KERNEL_RO	(__PGPROT_BASE | _PAGE_SUPER | _PAGE_DIRTY | _PAGE_WP)
314
315#define MAKE_GLOBAL(x) __pgprot((x) & ~_PAGE_NOTGLOBAL)
316
317#define PAGE_KERNEL		MAKE_GLOBAL(__PAGE_KERNEL)
318#define PAGE_KERNEL_RO		MAKE_GLOBAL(__PAGE_KERNEL_RO)
319#define PAGE_KERNEL_NOCACHE	MAKE_GLOBAL(__PAGE_KERNEL_NOCACHE)
320
321#define _PAGE_TABLE		(_PAGE_PRESENT | xAMPRx_SS_16Kb)
322
323#ifndef __ASSEMBLY__
324
325/*
326 * The FR451 can do execute protection by virtue of having separate TLB miss handlers for
327 * instruction access and for data access. However, we don't have enough reserved bits to say
328 * "execute only", so we don't bother. If you can read it, you can execute it and vice versa.
329 */
330#define __P000	PAGE_NONE
331#define __P001	PAGE_READONLY
332#define __P010	PAGE_COPY
333#define __P011	PAGE_COPY
334#define __P100	PAGE_READONLY
335#define __P101	PAGE_READONLY
336#define __P110	PAGE_COPY
337#define __P111	PAGE_COPY
338
339#define __S000	PAGE_NONE
340#define __S001	PAGE_READONLY
341#define __S010	PAGE_SHARED
342#define __S011	PAGE_SHARED
343#define __S100	PAGE_READONLY
344#define __S101	PAGE_READONLY
345#define __S110	PAGE_SHARED
346#define __S111	PAGE_SHARED
347
348/*
349 * Define this to warn about kernel memory accesses that are
350 * done without a 'access_ok(VERIFY_WRITE,..)'
351 */
352#undef TEST_ACCESS_OK
353
354#define pte_present(x)	(pte_val(x) & _PAGE_PRESENT)
355#define pte_clear(mm,addr,xp)	do { set_pte_at(mm, addr, xp, __pte(0)); } while (0)
356
357#define pmd_none(x)	(!pmd_val(x))
358#define pmd_present(x)	(pmd_val(x) & _PAGE_PRESENT)
359#define	pmd_bad(x)	(pmd_val(x) & xAMPRx_SS)
360#define pmd_clear(xp)	do { __set_pmd(xp, 0); } while(0)
361
362#define pmd_page_vaddr(pmd) \
363	((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
364
365#ifndef CONFIG_DISCONTIGMEM
366#define pmd_page(pmd)	(pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT))
367#endif
368
369#define pages_to_mb(x) ((x) >> (20-PAGE_SHIFT))
370
371/*
372 * The following only work if pte_present() is true.
373 * Undefined behaviour if not..
374 */
375static inline int pte_dirty(pte_t pte)		{ return (pte).pte & _PAGE_DIRTY; }
376static inline int pte_young(pte_t pte)		{ return (pte).pte & _PAGE_ACCESSED; }
377static inline int pte_write(pte_t pte)		{ return !((pte).pte & _PAGE_WP); }
378static inline int pte_special(pte_t pte)	{ return 0; }
379
380static inline pte_t pte_mkclean(pte_t pte)	{ (pte).pte &= ~_PAGE_DIRTY; return pte; }
381static inline pte_t pte_mkold(pte_t pte)	{ (pte).pte &= ~_PAGE_ACCESSED; return pte; }
382static inline pte_t pte_wrprotect(pte_t pte)	{ (pte).pte |= _PAGE_WP; return pte; }
383static inline pte_t pte_mkdirty(pte_t pte)	{ (pte).pte |= _PAGE_DIRTY; return pte; }
384static inline pte_t pte_mkyoung(pte_t pte)	{ (pte).pte |= _PAGE_ACCESSED; return pte; }
385static inline pte_t pte_mkwrite(pte_t pte)	{ (pte).pte &= ~_PAGE_WP; return pte; }
386static inline pte_t pte_mkspecial(pte_t pte)	{ return pte; }
387
388static inline int ptep_test_and_clear_young(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
389{
390	int i = test_and_clear_bit(_PAGE_BIT_ACCESSED, ptep);
391	asm volatile("dcf %M0" :: "U"(*ptep));
392	return i;
393}
394
395static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
396{
397	unsigned long x = xchg(&ptep->pte, 0);
398	asm volatile("dcf %M0" :: "U"(*ptep));
399	return __pte(x);
400}
401
402static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
403{
404	set_bit(_PAGE_BIT_WP, ptep);
405	asm volatile("dcf %M0" :: "U"(*ptep));
406}
407
408/*
409 * Macro to mark a page protection value as "uncacheable"
410 */
411#define pgprot_noncached(prot) (__pgprot(pgprot_val(prot) | _PAGE_NOCACHE))
412
413/*
414 * Conversion functions: convert a page and protection to a page entry,
415 * and a page entry and page directory to the page they refer to.
416 */
417
418#define mk_pte(page, pgprot)	pfn_pte(page_to_pfn(page), (pgprot))
419#define mk_pte_huge(entry)	((entry).pte_low |= _PAGE_PRESENT | _PAGE_PSE)
420
421/* This takes a physical page address that is used by the remapping functions */
422#define mk_pte_phys(physpage, pgprot)	pfn_pte((physpage) >> PAGE_SHIFT, pgprot)
423
424static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
425{
426	pte.pte &= _PAGE_CHG_MASK;
427	pte.pte |= pgprot_val(newprot);
428	return pte;
429}
430
431/* to find an entry in a page-table-directory. */
432#define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
433#define pgd_index_k(addr) pgd_index(addr)
434
435/* Find an entry in the bottom-level page table.. */
436#define __pte_index(address) (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
437
438/*
439 * the pte page can be thought of an array like this: pte_t[PTRS_PER_PTE]
440 *
441 * this macro returns the index of the entry in the pte page which would
442 * control the given virtual address
443 */
444#define pte_index(address) \
445		(((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
446#define pte_offset_kernel(dir, address) \
447	((pte_t *) pmd_page_vaddr(*(dir)) +  pte_index(address))
448
449#if defined(CONFIG_HIGHPTE)
450#define pte_offset_map(dir, address) \
451	((pte_t *)kmap_atomic(pmd_page(*(dir))) + pte_index(address))
452#define pte_unmap(pte) kunmap_atomic(pte)
453#else
454#define pte_offset_map(dir, address) \
455	((pte_t *)page_address(pmd_page(*(dir))) + pte_index(address))
456#define pte_unmap(pte) do { } while (0)
457#endif
458
459/*
460 * Handle swap and file entries
461 * - the PTE is encoded in the following format:
462 *	bit 0:		Must be 0 (!_PAGE_PRESENT)
463 *	bits 1-6:	Swap type
464 *	bits 7-31:	Swap offset
465 */
466#define __swp_type(x)			(((x).val >> 1) & 0x1f)
467#define __swp_offset(x)			((x).val >> 7)
468#define __swp_entry(type, offset)	((swp_entry_t) { ((type) << 1) | ((offset) << 7) })
469#define __pte_to_swp_entry(_pte)	((swp_entry_t) { (_pte).pte })
470#define __swp_entry_to_pte(x)		((pte_t) { (x).val })
471
472/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
473#define PageSkip(page)		(0)
474#define kern_addr_valid(addr)	(1)
475
476#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
477#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
478#define __HAVE_ARCH_PTEP_SET_WRPROTECT
479#define __HAVE_ARCH_PTE_SAME
480#include <asm-generic/pgtable.h>
481
482/*
483 * preload information about a newly instantiated PTE into the SCR0/SCR1 PGE cache
484 */
485static inline void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep)
486{
487	struct mm_struct *mm;
488	unsigned long ampr;
489
490	mm = current->mm;
491	if (mm) {
492		pgd_t *pge = pgd_offset(mm, address);
493		pud_t *pue = pud_offset(pge, address);
494		pmd_t *pme = pmd_offset(pue, address);
495
496		ampr = pme->ste[0] & 0xffffff00;
497		ampr |= xAMPRx_L | xAMPRx_SS_16Kb | xAMPRx_S | xAMPRx_C |
498			xAMPRx_V;
499	} else {
500		address = ULONG_MAX;
501		ampr = 0;
502	}
503
504	asm volatile("movgs %0,scr0\n"
505		     "movgs %0,scr1\n"
506		     "movgs %1,dampr4\n"
507		     "movgs %1,dampr5\n"
508		     :
509		     : "r"(address), "r"(ampr)
510		     );
511}
512
513#ifdef CONFIG_PROC_FS
514extern char *proc_pid_status_frv_cxnr(struct mm_struct *mm, char *buffer);
515#endif
516
517extern void __init pgtable_cache_init(void);
518
519#endif /* !__ASSEMBLY__ */
520#endif /* !CONFIG_MMU */
521
522#ifndef __ASSEMBLY__
523extern void __init paging_init(void);
524#endif /* !__ASSEMBLY__ */
525
526#endif /* _ASM_PGTABLE_H */
527