xref: /openbmc/linux/arch/um/kernel/tlb.c (revision d5cb9783536a41df9f9cba5b0a1d78047ed787f7)
1 /*
2  * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
3  * Licensed under the GPL
4  */
5 
6 #include "linux/mm.h"
7 #include "asm/page.h"
8 #include "asm/pgalloc.h"
9 #include "asm/tlbflush.h"
10 #include "choose-mode.h"
11 #include "mode_kern.h"
12 #include "user_util.h"
13 #include "tlb.h"
14 #include "mem.h"
15 #include "mem_user.h"
16 #include "os.h"
17 
18 static int add_mmap(unsigned long virt, unsigned long phys, unsigned long len,
19  		    int r, int w, int x, struct host_vm_op *ops, int *index,
20 		    int last_filled, union mm_context *mmu, void **flush,
21 		    int (*do_ops)(union mm_context *, struct host_vm_op *,
22 				  int, int, void **))
23 {
24         __u64 offset;
25 	struct host_vm_op *last;
26 	int fd, ret = 0;
27 
28 	fd = phys_mapping(phys, &offset);
29 	if(*index != -1){
30 		last = &ops[*index];
31 		if((last->type == MMAP) &&
32 		   (last->u.mmap.addr + last->u.mmap.len == virt) &&
33 		   (last->u.mmap.r == r) && (last->u.mmap.w == w) &&
34 		   (last->u.mmap.x == x) && (last->u.mmap.fd == fd) &&
35 		   (last->u.mmap.offset + last->u.mmap.len == offset)){
36 			last->u.mmap.len += len;
37 			return 0;
38 		}
39 	}
40 
41 	if(*index == last_filled){
42 		ret = (*do_ops)(mmu, ops, last_filled, 0, flush);
43 		*index = -1;
44 	}
45 
46 	ops[++*index] = ((struct host_vm_op) { .type	= MMAP,
47 			     			.u = { .mmap = {
48 						       .addr	= virt,
49 						       .len	= len,
50 						       .r	= r,
51 						       .w	= w,
52 						       .x	= x,
53 						       .fd	= fd,
54 						       .offset	= offset }
55 			   } });
56 	return ret;
57 }
58 
59 static int add_munmap(unsigned long addr, unsigned long len,
60 		      struct host_vm_op *ops, int *index, int last_filled,
61 		      union mm_context *mmu, void **flush,
62 		      int (*do_ops)(union mm_context *, struct host_vm_op *,
63 				    int, int, void **))
64 {
65 	struct host_vm_op *last;
66 	int ret = 0;
67 
68 	if(*index != -1){
69 		last = &ops[*index];
70 		if((last->type == MUNMAP) &&
71 		   (last->u.munmap.addr + last->u.mmap.len == addr)){
72 			last->u.munmap.len += len;
73 			return 0;
74 		}
75 	}
76 
77 	if(*index == last_filled){
78 		ret = (*do_ops)(mmu, ops, last_filled, 0, flush);
79 		*index = -1;
80 	}
81 
82 	ops[++*index] = ((struct host_vm_op) { .type	= MUNMAP,
83 			     		       .u = { .munmap = {
84 						        .addr	= addr,
85 							.len	= len } } });
86 	return ret;
87 }
88 
89 static int add_mprotect(unsigned long addr, unsigned long len, int r, int w,
90 			int x, struct host_vm_op *ops, int *index,
91 			int last_filled, union mm_context *mmu, void **flush,
92  			int (*do_ops)(union mm_context *, struct host_vm_op *,
93 				      int, int, void **))
94 {
95 	struct host_vm_op *last;
96 	int ret = 0;
97 
98 	if(*index != -1){
99 		last = &ops[*index];
100 		if((last->type == MPROTECT) &&
101 		   (last->u.mprotect.addr + last->u.mprotect.len == addr) &&
102 		   (last->u.mprotect.r == r) && (last->u.mprotect.w == w) &&
103 		   (last->u.mprotect.x == x)){
104 			last->u.mprotect.len += len;
105 			return 0;
106 		}
107 	}
108 
109 	if(*index == last_filled){
110 		ret = (*do_ops)(mmu, ops, last_filled, 0, flush);
111 		*index = -1;
112 	}
113 
114 	ops[++*index] = ((struct host_vm_op) { .type	= MPROTECT,
115 			     		       .u = { .mprotect = {
116 						       .addr	= addr,
117 						       .len	= len,
118 						       .r	= r,
119 						       .w	= w,
120 						       .x	= x } } });
121 	return ret;
122 }
123 
124 #define ADD_ROUND(n, inc) (((n) + (inc)) & ~((inc) - 1))
125 
126 void fix_range_common(struct mm_struct *mm, unsigned long start_addr,
127                       unsigned long end_addr, int force,
128 		      int (*do_ops)(union mm_context *, struct host_vm_op *,
129 				    int, int, void **))
130 {
131         pgd_t *npgd;
132         pud_t *npud;
133         pmd_t *npmd;
134         pte_t *npte;
135         union mm_context *mmu = &mm->context;
136         unsigned long addr, end;
137         int r, w, x;
138         struct host_vm_op ops[1];
139         void *flush = NULL;
140         int op_index = -1, last_op = sizeof(ops) / sizeof(ops[0]) - 1;
141         int ret = 0;
142 
143         if(mm == NULL) return;
144 
145         ops[0].type = NONE;
146         for(addr = start_addr; addr < end_addr && !ret;){
147                 npgd = pgd_offset(mm, addr);
148                 if(!pgd_present(*npgd)){
149                         end = ADD_ROUND(addr, PGDIR_SIZE);
150                         if(end > end_addr)
151                                 end = end_addr;
152                         if(force || pgd_newpage(*npgd)){
153                                 ret = add_munmap(addr, end - addr, ops,
154                                                  &op_index, last_op, mmu,
155                                                  &flush, do_ops);
156                                 pgd_mkuptodate(*npgd);
157                         }
158                         addr = end;
159                         continue;
160                 }
161 
162                 npud = pud_offset(npgd, addr);
163                 if(!pud_present(*npud)){
164                         end = ADD_ROUND(addr, PUD_SIZE);
165                         if(end > end_addr)
166                                 end = end_addr;
167                         if(force || pud_newpage(*npud)){
168                                 ret = add_munmap(addr, end - addr, ops,
169                                                  &op_index, last_op, mmu,
170                                                  &flush, do_ops);
171                                 pud_mkuptodate(*npud);
172                         }
173                         addr = end;
174                         continue;
175                 }
176 
177                 npmd = pmd_offset(npud, addr);
178                 if(!pmd_present(*npmd)){
179                         end = ADD_ROUND(addr, PMD_SIZE);
180                         if(end > end_addr)
181                                 end = end_addr;
182                         if(force || pmd_newpage(*npmd)){
183                                 ret = add_munmap(addr, end - addr, ops,
184                                                  &op_index, last_op, mmu,
185                                                  &flush, do_ops);
186                                 pmd_mkuptodate(*npmd);
187                         }
188                         addr = end;
189                         continue;
190                 }
191 
192                 npte = pte_offset_kernel(npmd, addr);
193                 r = pte_read(*npte);
194                 w = pte_write(*npte);
195                 x = pte_exec(*npte);
196 		if (!pte_young(*npte)) {
197 			r = 0;
198 			w = 0;
199 		} else if (!pte_dirty(*npte)) {
200 			w = 0;
201 		}
202                 if(force || pte_newpage(*npte)){
203                         if(pte_present(*npte))
204 			  ret = add_mmap(addr,
205 					 pte_val(*npte) & PAGE_MASK,
206 					 PAGE_SIZE, r, w, x, ops,
207 					 &op_index, last_op, mmu,
208 					 &flush, do_ops);
209 			else ret = add_munmap(addr, PAGE_SIZE, ops,
210 					      &op_index, last_op, mmu,
211 					      &flush, do_ops);
212                 }
213                 else if(pte_newprot(*npte))
214 			ret = add_mprotect(addr, PAGE_SIZE, r, w, x, ops,
215 					   &op_index, last_op, mmu,
216 					   &flush, do_ops);
217 
218                 *npte = pte_mkuptodate(*npte);
219                 addr += PAGE_SIZE;
220         }
221 
222 	if(!ret)
223 		ret = (*do_ops)(mmu, ops, op_index, 1, &flush);
224 
225 	/* This is not an else because ret is modified above */
226 	if(ret) {
227 		printk("fix_range_common: failed, killing current process\n");
228 		force_sig(SIGKILL, current);
229 	}
230 }
231 
232 int flush_tlb_kernel_range_common(unsigned long start, unsigned long end)
233 {
234         struct mm_struct *mm;
235         pgd_t *pgd;
236         pud_t *pud;
237         pmd_t *pmd;
238         pte_t *pte;
239         unsigned long addr, last;
240         int updated = 0, err;
241 
242         mm = &init_mm;
243         for(addr = start; addr < end;){
244                 pgd = pgd_offset(mm, addr);
245                 if(!pgd_present(*pgd)){
246                         last = ADD_ROUND(addr, PGDIR_SIZE);
247                         if(last > end)
248                                 last = end;
249                         if(pgd_newpage(*pgd)){
250                                 updated = 1;
251                                 err = os_unmap_memory((void *) addr,
252                                                       last - addr);
253                                 if(err < 0)
254                                         panic("munmap failed, errno = %d\n",
255                                               -err);
256                         }
257                         addr = last;
258                         continue;
259                 }
260 
261                 pud = pud_offset(pgd, addr);
262                 if(!pud_present(*pud)){
263                         last = ADD_ROUND(addr, PUD_SIZE);
264                         if(last > end)
265                                 last = end;
266                         if(pud_newpage(*pud)){
267                                 updated = 1;
268                                 err = os_unmap_memory((void *) addr,
269                                                       last - addr);
270                                 if(err < 0)
271                                         panic("munmap failed, errno = %d\n",
272                                               -err);
273                         }
274                         addr = last;
275                         continue;
276                 }
277 
278                 pmd = pmd_offset(pud, addr);
279                 if(!pmd_present(*pmd)){
280                         last = ADD_ROUND(addr, PMD_SIZE);
281                         if(last > end)
282                                 last = end;
283                         if(pmd_newpage(*pmd)){
284                                 updated = 1;
285                                 err = os_unmap_memory((void *) addr,
286                                                       last - addr);
287                                 if(err < 0)
288                                         panic("munmap failed, errno = %d\n",
289                                               -err);
290                         }
291                         addr = last;
292                         continue;
293                 }
294 
295                 pte = pte_offset_kernel(pmd, addr);
296                 if(!pte_present(*pte) || pte_newpage(*pte)){
297                         updated = 1;
298                         err = os_unmap_memory((void *) addr,
299                                               PAGE_SIZE);
300                         if(err < 0)
301                                 panic("munmap failed, errno = %d\n",
302                                       -err);
303                         if(pte_present(*pte))
304                                 map_memory(addr,
305                                            pte_val(*pte) & PAGE_MASK,
306                                            PAGE_SIZE, 1, 1, 1);
307                 }
308                 else if(pte_newprot(*pte)){
309                         updated = 1;
310                         os_protect_memory((void *) addr, PAGE_SIZE, 1, 1, 1);
311                 }
312                 addr += PAGE_SIZE;
313         }
314         return(updated);
315 }
316 
317 pgd_t *pgd_offset_proc(struct mm_struct *mm, unsigned long address)
318 {
319         return(pgd_offset(mm, address));
320 }
321 
322 pud_t *pud_offset_proc(pgd_t *pgd, unsigned long address)
323 {
324         return(pud_offset(pgd, address));
325 }
326 
327 pmd_t *pmd_offset_proc(pud_t *pud, unsigned long address)
328 {
329         return(pmd_offset(pud, address));
330 }
331 
332 pte_t *pte_offset_proc(pmd_t *pmd, unsigned long address)
333 {
334         return(pte_offset_kernel(pmd, address));
335 }
336 
337 pte_t *addr_pte(struct task_struct *task, unsigned long addr)
338 {
339         pgd_t *pgd = pgd_offset(task->mm, addr);
340         pud_t *pud = pud_offset(pgd, addr);
341         pmd_t *pmd = pmd_offset(pud, addr);
342 
343         return(pte_offset_map(pmd, addr));
344 }
345 
346 void flush_tlb_page(struct vm_area_struct *vma, unsigned long address)
347 {
348         address &= PAGE_MASK;
349         flush_tlb_range(vma, address, address + PAGE_SIZE);
350 }
351 
352 void flush_tlb_all(void)
353 {
354         flush_tlb_mm(current->mm);
355 }
356 
357 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
358 {
359         CHOOSE_MODE_PROC(flush_tlb_kernel_range_tt,
360                          flush_tlb_kernel_range_common, start, end);
361 }
362 
363 void flush_tlb_kernel_vm(void)
364 {
365         CHOOSE_MODE(flush_tlb_kernel_vm_tt(),
366                     flush_tlb_kernel_range_common(start_vm, end_vm));
367 }
368 
369 void __flush_tlb_one(unsigned long addr)
370 {
371         CHOOSE_MODE_PROC(__flush_tlb_one_tt, __flush_tlb_one_skas, addr);
372 }
373 
374 void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
375 		     unsigned long end)
376 {
377         CHOOSE_MODE_PROC(flush_tlb_range_tt, flush_tlb_range_skas, vma, start,
378                          end);
379 }
380 
381 void flush_tlb_mm(struct mm_struct *mm)
382 {
383         CHOOSE_MODE_PROC(flush_tlb_mm_tt, flush_tlb_mm_skas, mm);
384 }
385 
386 void force_flush_all(void)
387 {
388         CHOOSE_MODE(force_flush_all_tt(), force_flush_all_skas());
389 }
390 
391