1 /*
2  *  include/asm-s390/pgalloc.h
3  *
4  *  S390 version
5  *    Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
6  *    Author(s): Hartmut Penner (hp@de.ibm.com)
7  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
8  *
9  *  Derived from "include/asm-i386/pgalloc.h"
10  *    Copyright (C) 1994  Linus Torvalds
11  */
12 
13 #ifndef _S390_PGALLOC_H
14 #define _S390_PGALLOC_H
15 
16 #include <linux/config.h>
17 #include <asm/processor.h>
18 #include <linux/threads.h>
19 
20 #define pgd_quicklist (S390_lowcore.cpu_data.pgd_quick)
21 #define pmd_quicklist ((unsigned long *)0)
22 #define pte_quicklist (S390_lowcore.cpu_data.pte_quick)
23 #define pgtable_cache_size (S390_lowcore.cpu_data.pgtable_cache_sz)
24 
25 extern void diag10(unsigned long addr);
26 
27 /*
28  * Allocate and free page tables. The xxx_kernel() versions are
29  * used to allocate a kernel page table - this turns on ASN bits
30  * if any.
31  */
32 
get_pgd_slow(void)33 extern __inline__ pgd_t* get_pgd_slow(void)
34 {
35 	pgd_t *ret;
36         int i;
37 
38 	ret = (pgd_t *) __get_free_pages(GFP_KERNEL,1);
39         if (ret != NULL)
40 		for (i = 0; i < USER_PTRS_PER_PGD; i++)
41 			pmd_clear(pmd_offset(ret + i, i*PGDIR_SIZE));
42 	return ret;
43 }
44 
get_pgd_fast(void)45 extern __inline__ pgd_t* get_pgd_fast(void)
46 {
47         unsigned long *ret = pgd_quicklist;
48 
49         if (ret != NULL) {
50                 pgd_quicklist = (unsigned long *)(*ret);
51                 ret[0] = ret[1];
52                 pgtable_cache_size -= 2;
53         }
54         return (pgd_t *)ret;
55 }
56 
pgd_alloc(struct mm_struct * mm)57 extern __inline__ pgd_t *pgd_alloc(struct mm_struct *mm)
58 {
59 	pgd_t *pgd;
60 
61 	pgd = get_pgd_fast();
62 	if (!pgd)
63 		pgd = get_pgd_slow();
64 	return pgd;
65 }
66 
free_pgd_fast(pgd_t * pgd)67 extern __inline__ void free_pgd_fast(pgd_t *pgd)
68 {
69         *(unsigned long *)pgd = (unsigned long) pgd_quicklist;
70         pgd_quicklist = (unsigned long *) pgd;
71         pgtable_cache_size += 2;
72 }
73 
free_pgd_slow(pgd_t * pgd)74 extern __inline__ void free_pgd_slow(pgd_t *pgd)
75 {
76         free_pages((unsigned long) pgd, 1);
77 }
78 
79 #define pgd_free(pgd)           free_pgd_fast(pgd)
80 
81 /*
82  * page middle directory allocation/free routines.
83  * We don't use pmd cache, so these are dummy routines. This
84  * code never triggers because the pgd will always be present.
85  */
86 #define pmd_alloc_one_fast(mm, address) ({ BUG(); ((pmd_t *)1); })
87 #define pmd_alloc_one(mm,address)       ({ BUG(); ((pmd_t *)2); })
88 #define pmd_free(x)                     do { } while (0)
89 #define pmd_free_slow(x)		do { } while (0)
90 #define pmd_free_fast(x)                do { } while (0)
91 #define pgd_populate(mm, pmd, pte)      BUG()
92 
pmd_populate(struct mm_struct * mm,pmd_t * pmd,pte_t * pte)93 extern inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd, pte_t *pte)
94 {
95 	pmd_val(pmd[0]) = _PAGE_TABLE + __pa(pte);
96 	pmd_val(pmd[1]) = _PAGE_TABLE + __pa(pte+256);
97 	pmd_val(pmd[2]) = _PAGE_TABLE + __pa(pte+512);
98 	pmd_val(pmd[3]) = _PAGE_TABLE + __pa(pte+768);
99 }
100 
101 /*
102  * page table entry allocation/free routines.
103  */
pte_alloc_one(struct mm_struct * mm,unsigned long vmaddr)104 extern inline pte_t * pte_alloc_one(struct mm_struct *mm, unsigned long vmaddr)
105 {
106 	pte_t *pte;
107         int i;
108 
109 	pte = (pte_t *) __get_free_page(GFP_KERNEL);
110 	if (pte != NULL) {
111 		for (i=0; i < PTRS_PER_PTE; i++)
112 			pte_clear(pte+i);
113 	}
114 	return pte;
115 }
116 
117 extern __inline__ pte_t *
pte_alloc_one_fast(struct mm_struct * mm,unsigned long address)118 pte_alloc_one_fast(struct mm_struct *mm, unsigned long address)
119 {
120         unsigned long *ret = (unsigned long *) pte_quicklist;
121 
122         if (ret != NULL) {
123                 pte_quicklist = (unsigned long *)(*ret);
124                 ret[0] = ret[1];
125                 pgtable_cache_size--;
126         }
127         return (pte_t *)ret;
128 }
129 
pte_free_fast(pte_t * pte)130 extern __inline__ void pte_free_fast(pte_t *pte)
131 {
132         *(unsigned long *)pte = (unsigned long) pte_quicklist;
133         pte_quicklist = (unsigned long *) pte;
134         pgtable_cache_size++;
135 }
136 
pte_free_slow(pte_t * pte)137 extern __inline__ void pte_free_slow(pte_t *pte)
138 {
139         free_page((unsigned long) pte);
140 }
141 
142 #define pte_free(pte)           pte_free_fast(pte)
143 
144 extern int do_check_pgt_cache(int, int);
145 
146 /*
147  * This establishes kernel virtual mappings (e.g., as a result of a
148  * vmalloc call).  Since s390-esame uses a separate kernel page table,
149  * there is nothing to do here... :)
150  */
151 #define set_pgdir(addr,entry) do { } while(0)
152 
153 /*
154  * TLB flushing:
155  *
156  *  - flush_tlb() flushes the current mm struct TLBs
157  *  - flush_tlb_all() flushes all processes TLBs
158  *    called only from vmalloc/vfree
159  *  - flush_tlb_mm(mm) flushes the specified mm context TLB's
160  *  - flush_tlb_page(vma, vmaddr) flushes one page
161  *  - flush_tlb_range(mm, start, end) flushes a range of pages
162  *  - flush_tlb_pgtables(mm, start, end) flushes a range of page tables
163  */
164 
165 /*
166  * S/390 has three ways of flushing TLBs
167  * 'ptlb' does a flush of the local processor
168  * 'csp' flushes the TLBs on all PUs of a SMP
169  * 'ipte' invalidates a pte in a page table and flushes that out of
170  * the TLBs of all PUs of a SMP
171  */
172 
173 #define local_flush_tlb() \
174 do {  __asm__ __volatile__("ptlb": : :"memory"); } while (0)
175 
176 
177 #ifndef CONFIG_SMP
178 
179 /*
180  * We always need to flush, since s390 does not flush tlb
181  * on each context switch
182  */
183 
flush_tlb(void)184 static inline void flush_tlb(void)
185 {
186 	local_flush_tlb();
187 }
flush_tlb_all(void)188 static inline void flush_tlb_all(void)
189 {
190 	local_flush_tlb();
191 }
flush_tlb_mm(struct mm_struct * mm)192 static inline void flush_tlb_mm(struct mm_struct *mm)
193 {
194 	local_flush_tlb();
195 }
flush_tlb_page(struct vm_area_struct * vma,unsigned long addr)196 static inline void flush_tlb_page(struct vm_area_struct *vma,
197 				  unsigned long addr)
198 {
199 	local_flush_tlb();
200 }
flush_tlb_range(struct mm_struct * mm,unsigned long start,unsigned long end)201 static inline void flush_tlb_range(struct mm_struct *mm,
202 				   unsigned long start, unsigned long end)
203 {
204 	local_flush_tlb();
205 }
206 
207 #else
208 
209 #include <asm/smp.h>
210 
211 extern void smp_ptlb_all(void);
global_flush_tlb_csp(void)212 static inline void global_flush_tlb_csp(void)
213 {
214 	int cs1=0,dum=0;
215 	int *adr;
216 	long long dummy=0;
217 	adr = (int*) (((int)(((int*) &dummy)+1) & 0xfffffffc)|1);
218 	__asm__ __volatile__("lr    2,%0\n\t"
219                              "lr    3,%1\n\t"
220                              "lr    4,%2\n\t"
221                              "csp   2,4" :
222                              : "d" (cs1), "d" (dum), "d" (adr)
223                              : "2", "3", "4");
224 }
global_flush_tlb(void)225 static inline void global_flush_tlb(void)
226 {
227 	if (MACHINE_HAS_CSP)
228 		global_flush_tlb_csp();
229 	else
230 		smp_ptlb_all();
231 }
232 
233 /*
234  * We only have to do global flush of tlb if process run since last
235  * flush on any other pu than current.
236  * If we have threads (mm->count > 1) we always do a global flush,
237  * since the process runs on more than one processor at the same time.
238  */
239 
__flush_tlb_mm(struct mm_struct * mm)240 static inline void __flush_tlb_mm(struct mm_struct * mm)
241 {
242 	if (mm->cpu_vm_mask != (1UL << smp_processor_id())) {
243 		/* mm was active on more than one cpu. */
244 		if (mm == current->active_mm &&
245 		    atomic_read(&mm->mm_users) == 1)
246 			/* this cpu is the only one using the mm. */
247 			mm->cpu_vm_mask = 1UL << smp_processor_id();
248 		global_flush_tlb();
249 	} else
250 		local_flush_tlb();
251 }
252 
flush_tlb(void)253 static inline void flush_tlb(void)
254 {
255 	__flush_tlb_mm(current->mm);
256 }
flush_tlb_all(void)257 static inline void flush_tlb_all(void)
258 {
259 	global_flush_tlb();
260 }
flush_tlb_mm(struct mm_struct * mm)261 static inline void flush_tlb_mm(struct mm_struct *mm)
262 {
263 	__flush_tlb_mm(mm);
264 }
flush_tlb_page(struct vm_area_struct * vma,unsigned long addr)265 static inline void flush_tlb_page(struct vm_area_struct *vma,
266 				  unsigned long addr)
267 {
268 	__flush_tlb_mm(vma->vm_mm);
269 }
flush_tlb_range(struct mm_struct * mm,unsigned long start,unsigned long end)270 static inline void flush_tlb_range(struct mm_struct *mm,
271 				   unsigned long start, unsigned long end)
272 {
273 	__flush_tlb_mm(mm);
274 }
275 
276 #endif
277 
flush_tlb_pgtables(struct mm_struct * mm,unsigned long start,unsigned long end)278 extern inline void flush_tlb_pgtables(struct mm_struct *mm,
279                                       unsigned long start, unsigned long end)
280 {
281         /* S/390 does not keep any page table caches in TLB */
282 }
283 
284 
ptep_test_and_clear_and_flush_young(struct vm_area_struct * vma,unsigned long address,pte_t * ptep)285 static inline int ptep_test_and_clear_and_flush_young(struct vm_area_struct *vma,
286                                                       unsigned long address, pte_t *ptep)
287 {
288 	/* No need to flush TLB; bits are in storage key */
289 	return ptep_test_and_clear_young(ptep);
290 }
291 
ptep_test_and_clear_and_flush_dirty(struct vm_area_struct * vma,unsigned long address,pte_t * ptep)292 static inline int ptep_test_and_clear_and_flush_dirty(struct vm_area_struct *vma,
293                                                       unsigned long address, pte_t *ptep)
294 {
295 	/* No need to flush TLB; bits are in storage key */
296 	return ptep_test_and_clear_dirty(ptep);
297 }
298 
ptep_invalidate(struct vm_area_struct * vma,unsigned long address,pte_t * ptep)299 static inline pte_t ptep_invalidate(struct vm_area_struct *vma,
300                                     unsigned long address, pte_t *ptep)
301 {
302 	pte_t pte = *ptep;
303 	if (!(pte_val(pte) & _PAGE_INVALID)) {
304 		/* S390 has 1mb segments, we are emulating 4MB segments */
305 		pte_t *pto = (pte_t *) (((unsigned long) ptep) & 0x7ffffc00);
306 		__asm__ __volatile__ ("ipte %0,%1" : : "a" (pto), "a" (address));
307 	}
308 	pte_clear(ptep);
309 	return pte;
310 }
311 
ptep_establish(struct vm_area_struct * vma,unsigned long address,pte_t * ptep,pte_t entry)312 static inline void ptep_establish(struct vm_area_struct *vma,
313                                   unsigned long address, pte_t *ptep, pte_t entry)
314 {
315 	ptep_invalidate(vma, address, ptep);
316 	set_pte(ptep, entry);
317 }
318 
319 #endif /* _S390_PGALLOC_H */
320