Commit | Line | Data |
---|---|---|
2e5d9c85 | 1 | /* |
2 | * Handle caching attributes in page tables (PAT) | |
3 | * | |
4 | * Authors: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> | |
5 | * Suresh B Siddha <suresh.b.siddha@intel.com> | |
6 | * | |
7 | * Loosely based on earlier PAT patchset from Eric Biederman and Andi Kleen. | |
8 | */ | |
9 | ||
ad2cde16 IM |
10 | #include <linux/seq_file.h> |
11 | #include <linux/bootmem.h> | |
12 | #include <linux/debugfs.h> | |
2e5d9c85 | 13 | #include <linux/kernel.h> |
92b9af9e | 14 | #include <linux/module.h> |
2e5d9c85 | 15 | #include <linux/gfp.h> |
ad2cde16 | 16 | #include <linux/mm.h> |
2e5d9c85 | 17 | #include <linux/fs.h> |
335ef896 | 18 | #include <linux/rbtree.h> |
2e5d9c85 | 19 | |
ad2cde16 | 20 | #include <asm/cacheflush.h> |
2e5d9c85 | 21 | #include <asm/processor.h> |
ad2cde16 | 22 | #include <asm/tlbflush.h> |
2e5d9c85 | 23 | #include <asm/pgtable.h> |
2e5d9c85 | 24 | #include <asm/fcntl.h> |
ad2cde16 | 25 | #include <asm/e820.h> |
2e5d9c85 | 26 | #include <asm/mtrr.h> |
ad2cde16 IM |
27 | #include <asm/page.h> |
28 | #include <asm/msr.h> | |
29 | #include <asm/pat.h> | |
e7f260a2 | 30 | #include <asm/io.h> |
2e5d9c85 | 31 | |
8d4a4300 | 32 | #ifdef CONFIG_X86_PAT |
499f8f84 | 33 | int __read_mostly pat_enabled = 1; |
2e5d9c85 | 34 | |
1ee4bd92 | 35 | static inline void pat_disable(const char *reason) |
2e5d9c85 | 36 | { |
499f8f84 | 37 | pat_enabled = 0; |
8d4a4300 | 38 | printk(KERN_INFO "%s\n", reason); |
2e5d9c85 | 39 | } |
2e5d9c85 | 40 | |
be524fb9 | 41 | static int __init nopat(char *str) |
2e5d9c85 | 42 | { |
8d4a4300 | 43 | pat_disable("PAT support disabled."); |
2e5d9c85 | 44 | return 0; |
45 | } | |
8d4a4300 | 46 | early_param("nopat", nopat); |
75a04811 PA |
47 | #else |
48 | static inline void pat_disable(const char *reason) | |
49 | { | |
50 | (void)reason; | |
51 | } | |
8d4a4300 TG |
52 | #endif |
53 | ||
77b52b4c VP |
54 | |
55 | static int debug_enable; | |
ad2cde16 | 56 | |
77b52b4c VP |
57 | static int __init pat_debug_setup(char *str) |
58 | { | |
59 | debug_enable = 1; | |
60 | return 0; | |
61 | } | |
62 | __setup("debugpat", pat_debug_setup); | |
63 | ||
64 | #define dprintk(fmt, arg...) \ | |
65 | do { if (debug_enable) printk(KERN_INFO fmt, ##arg); } while (0) | |
66 | ||
67 | ||
8d4a4300 | 68 | static u64 __read_mostly boot_pat_state; |
2e5d9c85 | 69 | |
70 | enum { | |
71 | PAT_UC = 0, /* uncached */ | |
72 | PAT_WC = 1, /* Write combining */ | |
73 | PAT_WT = 4, /* Write Through */ | |
74 | PAT_WP = 5, /* Write Protected */ | |
75 | PAT_WB = 6, /* Write Back (default) */ | |
76 | PAT_UC_MINUS = 7, /* UC, but can be overriden by MTRR */ | |
77 | }; | |
78 | ||
cd7a4e93 | 79 | #define PAT(x, y) ((u64)PAT_ ## y << ((x)*8)) |
2e5d9c85 | 80 | |
81 | void pat_init(void) | |
82 | { | |
83 | u64 pat; | |
e23a8b6a | 84 | bool boot_cpu = !boot_pat_state; |
2e5d9c85 | 85 | |
499f8f84 | 86 | if (!pat_enabled) |
2e5d9c85 | 87 | return; |
88 | ||
75a04811 PA |
89 | if (!cpu_has_pat) { |
90 | if (!boot_pat_state) { | |
91 | pat_disable("PAT not supported by CPU."); | |
92 | return; | |
93 | } else { | |
94 | /* | |
95 | * If this happens we are on a secondary CPU, but | |
96 | * switched to PAT on the boot CPU. We have no way to | |
97 | * undo PAT. | |
98 | */ | |
99 | printk(KERN_ERR "PAT enabled, " | |
100 | "but not supported by secondary CPU\n"); | |
101 | BUG(); | |
102 | } | |
8d4a4300 | 103 | } |
2e5d9c85 | 104 | |
105 | /* Set PWT to Write-Combining. All other bits stay the same */ | |
106 | /* | |
107 | * PTE encoding used in Linux: | |
108 | * PAT | |
109 | * |PCD | |
110 | * ||PWT | |
111 | * ||| | |
112 | * 000 WB _PAGE_CACHE_WB | |
113 | * 001 WC _PAGE_CACHE_WC | |
114 | * 010 UC- _PAGE_CACHE_UC_MINUS | |
115 | * 011 UC _PAGE_CACHE_UC | |
116 | * PAT bit unused | |
117 | */ | |
cd7a4e93 AH |
118 | pat = PAT(0, WB) | PAT(1, WC) | PAT(2, UC_MINUS) | PAT(3, UC) | |
119 | PAT(4, WB) | PAT(5, WC) | PAT(6, UC_MINUS) | PAT(7, UC); | |
2e5d9c85 | 120 | |
121 | /* Boot CPU check */ | |
8d4a4300 | 122 | if (!boot_pat_state) |
2e5d9c85 | 123 | rdmsrl(MSR_IA32_CR_PAT, boot_pat_state); |
2e5d9c85 | 124 | |
125 | wrmsrl(MSR_IA32_CR_PAT, pat); | |
e23a8b6a RD |
126 | |
127 | if (boot_cpu) | |
128 | printk(KERN_INFO "x86 PAT enabled: cpu %d, old 0x%Lx, new 0x%Lx\n", | |
129 | smp_processor_id(), boot_pat_state, pat); | |
2e5d9c85 | 130 | } |
131 | ||
132 | #undef PAT | |
133 | ||
134 | static char *cattr_name(unsigned long flags) | |
135 | { | |
136 | switch (flags & _PAGE_CACHE_MASK) { | |
cd7a4e93 AH |
137 | case _PAGE_CACHE_UC: return "uncached"; |
138 | case _PAGE_CACHE_UC_MINUS: return "uncached-minus"; | |
139 | case _PAGE_CACHE_WB: return "write-back"; | |
140 | case _PAGE_CACHE_WC: return "write-combining"; | |
141 | default: return "broken"; | |
2e5d9c85 | 142 | } |
143 | } | |
144 | ||
145 | /* | |
146 | * The global memtype list keeps track of memory type for specific | |
147 | * physical memory areas. Conflicting memory types in different | |
148 | * mappings can cause CPU cache corruption. To avoid this we keep track. | |
149 | * | |
150 | * The list is sorted based on starting address and can contain multiple | |
151 | * entries for each address (this allows reference counting for overlapping | |
152 | * areas). All the aliases have the same cache attributes of course. | |
153 | * Zero attributes are represented as holes. | |
154 | * | |
335ef896 VP |
155 | * The data structure is a list that is also organized as an rbtree |
156 | * sorted on the start address of memtype range. | |
2e5d9c85 | 157 | * |
335ef896 | 158 | * memtype_lock protects both the linear list and rbtree. |
2e5d9c85 | 159 | */ |
160 | ||
161 | struct memtype { | |
ad2cde16 IM |
162 | u64 start; |
163 | u64 end; | |
164 | unsigned long type; | |
165 | struct list_head nd; | |
335ef896 | 166 | struct rb_node rb; |
2e5d9c85 | 167 | }; |
168 | ||
335ef896 | 169 | static struct rb_root memtype_rbroot = RB_ROOT; |
2e5d9c85 | 170 | static LIST_HEAD(memtype_list); |
ad2cde16 | 171 | static DEFINE_SPINLOCK(memtype_lock); /* protects memtype list */ |
2e5d9c85 | 172 | |
335ef896 VP |
173 | static struct memtype *memtype_rb_search(struct rb_root *root, u64 start) |
174 | { | |
175 | struct rb_node *node = root->rb_node; | |
176 | struct memtype *last_lower = NULL; | |
177 | ||
178 | while (node) { | |
179 | struct memtype *data = container_of(node, struct memtype, rb); | |
180 | ||
181 | if (data->start < start) { | |
182 | last_lower = data; | |
183 | node = node->rb_right; | |
184 | } else if (data->start > start) { | |
185 | node = node->rb_left; | |
186 | } else | |
187 | return data; | |
188 | } | |
189 | ||
190 | /* Will return NULL if there is no entry with its start <= start */ | |
191 | return last_lower; | |
192 | } | |
193 | ||
194 | static void memtype_rb_insert(struct rb_root *root, struct memtype *data) | |
195 | { | |
196 | struct rb_node **new = &(root->rb_node); | |
197 | struct rb_node *parent = NULL; | |
198 | ||
199 | while (*new) { | |
200 | struct memtype *this = container_of(*new, struct memtype, rb); | |
201 | ||
202 | parent = *new; | |
203 | if (data->start <= this->start) | |
204 | new = &((*new)->rb_left); | |
205 | else if (data->start > this->start) | |
206 | new = &((*new)->rb_right); | |
207 | } | |
208 | ||
209 | rb_link_node(&data->rb, parent, new); | |
210 | rb_insert_color(&data->rb, root); | |
211 | } | |
212 | ||
2e5d9c85 | 213 | /* |
214 | * Does intersection of PAT memory type and MTRR memory type and returns | |
215 | * the resulting memory type as PAT understands it. | |
216 | * (Type in pat and mtrr will not have same value) | |
217 | * The intersection is based on "Effective Memory Type" tables in IA-32 | |
218 | * SDM vol 3a | |
219 | */ | |
6cf514fc | 220 | static unsigned long pat_x_mtrr_type(u64 start, u64 end, unsigned long req_type) |
2e5d9c85 | 221 | { |
c26421d0 VP |
222 | /* |
223 | * Look for MTRR hint to get the effective type in case where PAT | |
224 | * request is for WB. | |
225 | */ | |
dd0c7c49 AH |
226 | if (req_type == _PAGE_CACHE_WB) { |
227 | u8 mtrr_type; | |
228 | ||
229 | mtrr_type = mtrr_type_lookup(start, end); | |
b6ff32d9 SS |
230 | if (mtrr_type != MTRR_TYPE_WRBACK) |
231 | return _PAGE_CACHE_UC_MINUS; | |
232 | ||
233 | return _PAGE_CACHE_WB; | |
dd0c7c49 AH |
234 | } |
235 | ||
236 | return req_type; | |
2e5d9c85 | 237 | } |
238 | ||
ad2cde16 IM |
239 | static int |
240 | chk_conflict(struct memtype *new, struct memtype *entry, unsigned long *type) | |
64fe44c3 AH |
241 | { |
242 | if (new->type != entry->type) { | |
243 | if (type) { | |
244 | new->type = entry->type; | |
245 | *type = entry->type; | |
246 | } else | |
247 | goto conflict; | |
248 | } | |
249 | ||
250 | /* check overlaps with more than one entry in the list */ | |
251 | list_for_each_entry_continue(entry, &memtype_list, nd) { | |
252 | if (new->end <= entry->start) | |
253 | break; | |
254 | else if (new->type != entry->type) | |
255 | goto conflict; | |
256 | } | |
257 | return 0; | |
258 | ||
259 | conflict: | |
260 | printk(KERN_INFO "%s:%d conflicting memory types " | |
261 | "%Lx-%Lx %s<->%s\n", current->comm, current->pid, new->start, | |
262 | new->end, cattr_name(new->type), cattr_name(entry->type)); | |
263 | return -EBUSY; | |
264 | } | |
265 | ||
be03d9e8 SS |
266 | static int pat_pagerange_is_ram(unsigned long start, unsigned long end) |
267 | { | |
268 | int ram_page = 0, not_rampage = 0; | |
269 | unsigned long page_nr; | |
270 | ||
271 | for (page_nr = (start >> PAGE_SHIFT); page_nr < (end >> PAGE_SHIFT); | |
272 | ++page_nr) { | |
273 | /* | |
274 | * For legacy reasons, physical address range in the legacy ISA | |
275 | * region is tracked as non-RAM. This will allow users of | |
276 | * /dev/mem to map portions of legacy ISA region, even when | |
277 | * some of those portions are listed(or not even listed) with | |
278 | * different e820 types(RAM/reserved/..) | |
279 | */ | |
280 | if (page_nr >= (ISA_END_ADDRESS >> PAGE_SHIFT) && | |
281 | page_is_ram(page_nr)) | |
282 | ram_page = 1; | |
283 | else | |
284 | not_rampage = 1; | |
285 | ||
286 | if (ram_page == not_rampage) | |
287 | return -1; | |
288 | } | |
289 | ||
290 | return ram_page; | |
291 | } | |
292 | ||
9542ada8 | 293 | /* |
f5841740 VP |
294 | * For RAM pages, we use page flags to mark the pages with appropriate type. |
295 | * Here we do two pass: | |
296 | * - Find the memtype of all the pages in the range, look for any conflicts | |
297 | * - In case of no conflicts, set the new memtype for pages in the range | |
9542ada8 | 298 | * |
f5841740 | 299 | * Caller must hold memtype_lock for atomicity. |
9542ada8 SS |
300 | */ |
301 | static int reserve_ram_pages_type(u64 start, u64 end, unsigned long req_type, | |
ad2cde16 | 302 | unsigned long *new_type) |
9542ada8 SS |
303 | { |
304 | struct page *page; | |
f5841740 VP |
305 | u64 pfn; |
306 | ||
307 | if (req_type == _PAGE_CACHE_UC) { | |
308 | /* We do not support strong UC */ | |
309 | WARN_ON_ONCE(1); | |
310 | req_type = _PAGE_CACHE_UC_MINUS; | |
311 | } | |
9542ada8 SS |
312 | |
313 | for (pfn = (start >> PAGE_SHIFT); pfn < (end >> PAGE_SHIFT); ++pfn) { | |
f5841740 | 314 | unsigned long type; |
9542ada8 | 315 | |
f5841740 VP |
316 | page = pfn_to_page(pfn); |
317 | type = get_page_memtype(page); | |
318 | if (type != -1) { | |
319 | printk(KERN_INFO "reserve_ram_pages_type failed " | |
320 | "0x%Lx-0x%Lx, track 0x%lx, req 0x%lx\n", | |
321 | start, end, type, req_type); | |
322 | if (new_type) | |
323 | *new_type = type; | |
324 | ||
325 | return -EBUSY; | |
326 | } | |
9542ada8 | 327 | } |
9542ada8 | 328 | |
f5841740 VP |
329 | if (new_type) |
330 | *new_type = req_type; | |
331 | ||
332 | for (pfn = (start >> PAGE_SHIFT); pfn < (end >> PAGE_SHIFT); ++pfn) { | |
9542ada8 | 333 | page = pfn_to_page(pfn); |
f5841740 | 334 | set_page_memtype(page, req_type); |
9542ada8 | 335 | } |
f5841740 | 336 | return 0; |
9542ada8 SS |
337 | } |
338 | ||
339 | static int free_ram_pages_type(u64 start, u64 end) | |
340 | { | |
341 | struct page *page; | |
f5841740 | 342 | u64 pfn; |
9542ada8 SS |
343 | |
344 | for (pfn = (start >> PAGE_SHIFT); pfn < (end >> PAGE_SHIFT); ++pfn) { | |
345 | page = pfn_to_page(pfn); | |
f5841740 | 346 | set_page_memtype(page, -1); |
9542ada8 SS |
347 | } |
348 | return 0; | |
9542ada8 SS |
349 | } |
350 | ||
e7f260a2 | 351 | /* |
352 | * req_type typically has one of the: | |
353 | * - _PAGE_CACHE_WB | |
354 | * - _PAGE_CACHE_WC | |
355 | * - _PAGE_CACHE_UC_MINUS | |
356 | * - _PAGE_CACHE_UC | |
357 | * | |
358 | * req_type will have a special case value '-1', when requester want to inherit | |
359 | * the memory type from mtrr (if WB), existing PAT, defaulting to UC_MINUS. | |
360 | * | |
ac97991e AH |
361 | * If new_type is NULL, function will return an error if it cannot reserve the |
362 | * region with req_type. If new_type is non-NULL, function will return | |
363 | * available type in new_type in case of no error. In case of any error | |
e7f260a2 | 364 | * it will return a negative return value. |
365 | */ | |
2e5d9c85 | 366 | int reserve_memtype(u64 start, u64 end, unsigned long req_type, |
ad2cde16 | 367 | unsigned long *new_type) |
2e5d9c85 | 368 | { |
ac97991e | 369 | struct memtype *new, *entry; |
2e5d9c85 | 370 | unsigned long actual_type; |
f6887264 | 371 | struct list_head *where; |
9542ada8 | 372 | int is_range_ram; |
ad2cde16 | 373 | int err = 0; |
2e5d9c85 | 374 | |
ad2cde16 | 375 | BUG_ON(start >= end); /* end is exclusive */ |
69e26be9 | 376 | |
499f8f84 | 377 | if (!pat_enabled) { |
e7f260a2 | 378 | /* This is identical to page table setting without PAT */ |
ac97991e AH |
379 | if (new_type) { |
380 | if (req_type == -1) | |
381 | *new_type = _PAGE_CACHE_WB; | |
5fc51746 VP |
382 | else if (req_type == _PAGE_CACHE_WC) |
383 | *new_type = _PAGE_CACHE_UC_MINUS; | |
ac97991e AH |
384 | else |
385 | *new_type = req_type & _PAGE_CACHE_MASK; | |
e7f260a2 | 386 | } |
2e5d9c85 | 387 | return 0; |
388 | } | |
389 | ||
390 | /* Low ISA region is always mapped WB in page table. No need to track */ | |
bcc643dc | 391 | if (is_ISA_range(start, end - 1)) { |
ac97991e AH |
392 | if (new_type) |
393 | *new_type = _PAGE_CACHE_WB; | |
2e5d9c85 | 394 | return 0; |
395 | } | |
396 | ||
b6ff32d9 SS |
397 | /* |
398 | * Call mtrr_lookup to get the type hint. This is an | |
399 | * optimization for /dev/mem mmap'ers into WB memory (BIOS | |
400 | * tools and ACPI tools). Use WB request for WB memory and use | |
401 | * UC_MINUS otherwise. | |
402 | */ | |
403 | actual_type = pat_x_mtrr_type(start, end, req_type & _PAGE_CACHE_MASK); | |
2e5d9c85 | 404 | |
95971342 SS |
405 | if (new_type) |
406 | *new_type = actual_type; | |
407 | ||
be03d9e8 | 408 | is_range_ram = pat_pagerange_is_ram(start, end); |
f5841740 VP |
409 | if (is_range_ram == 1) { |
410 | ||
411 | spin_lock(&memtype_lock); | |
412 | err = reserve_ram_pages_type(start, end, req_type, new_type); | |
413 | spin_unlock(&memtype_lock); | |
414 | ||
415 | return err; | |
416 | } else if (is_range_ram < 0) { | |
9542ada8 | 417 | return -EINVAL; |
f5841740 | 418 | } |
9542ada8 | 419 | |
ac97991e AH |
420 | new = kmalloc(sizeof(struct memtype), GFP_KERNEL); |
421 | if (!new) | |
2e5d9c85 | 422 | return -ENOMEM; |
423 | ||
ad2cde16 IM |
424 | new->start = start; |
425 | new->end = end; | |
426 | new->type = actual_type; | |
2e5d9c85 | 427 | |
2e5d9c85 | 428 | spin_lock(&memtype_lock); |
429 | ||
430 | /* Search for existing mapping that overlaps the current range */ | |
f6887264 | 431 | where = NULL; |
dcb73bf4 | 432 | list_for_each_entry(entry, &memtype_list, nd) { |
33af9039 | 433 | if (end <= entry->start) { |
f6887264 | 434 | where = entry->nd.prev; |
2e5d9c85 | 435 | break; |
33af9039 | 436 | } else if (start <= entry->start) { /* end > entry->start */ |
64fe44c3 | 437 | err = chk_conflict(new, entry, new_type); |
33af9039 AH |
438 | if (!err) { |
439 | dprintk("Overlap at 0x%Lx-0x%Lx\n", | |
440 | entry->start, entry->end); | |
441 | where = entry->nd.prev; | |
2e5d9c85 | 442 | } |
2e5d9c85 | 443 | break; |
33af9039 | 444 | } else if (start < entry->end) { /* start > entry->start */ |
64fe44c3 | 445 | err = chk_conflict(new, entry, new_type); |
33af9039 AH |
446 | if (!err) { |
447 | dprintk("Overlap at 0x%Lx-0x%Lx\n", | |
448 | entry->start, entry->end); | |
80c5e73d VP |
449 | |
450 | /* | |
451 | * Move to right position in the linked | |
452 | * list to add this new entry | |
453 | */ | |
454 | list_for_each_entry_continue(entry, | |
455 | &memtype_list, nd) { | |
456 | if (start <= entry->start) { | |
457 | where = entry->nd.prev; | |
458 | break; | |
459 | } | |
460 | } | |
2e5d9c85 | 461 | } |
2e5d9c85 | 462 | break; |
463 | } | |
464 | } | |
465 | ||
466 | if (err) { | |
3e9c83b3 AH |
467 | printk(KERN_INFO "reserve_memtype failed 0x%Lx-0x%Lx, " |
468 | "track %s, req %s\n", | |
469 | start, end, cattr_name(new->type), cattr_name(req_type)); | |
ac97991e | 470 | kfree(new); |
2e5d9c85 | 471 | spin_unlock(&memtype_lock); |
ad2cde16 | 472 | |
2e5d9c85 | 473 | return err; |
474 | } | |
475 | ||
f6887264 AH |
476 | if (where) |
477 | list_add(&new->nd, where); | |
478 | else | |
ac97991e | 479 | list_add_tail(&new->nd, &memtype_list); |
6997ab49 | 480 | |
335ef896 VP |
481 | memtype_rb_insert(&memtype_rbroot, new); |
482 | ||
2e5d9c85 | 483 | spin_unlock(&memtype_lock); |
3e9c83b3 AH |
484 | |
485 | dprintk("reserve_memtype added 0x%Lx-0x%Lx, track %s, req %s, ret %s\n", | |
486 | start, end, cattr_name(new->type), cattr_name(req_type), | |
487 | new_type ? cattr_name(*new_type) : "-"); | |
488 | ||
2e5d9c85 | 489 | return err; |
490 | } | |
491 | ||
492 | int free_memtype(u64 start, u64 end) | |
493 | { | |
335ef896 | 494 | struct memtype *entry, *saved_entry; |
2e5d9c85 | 495 | int err = -EINVAL; |
9542ada8 | 496 | int is_range_ram; |
2e5d9c85 | 497 | |
69e26be9 | 498 | if (!pat_enabled) |
2e5d9c85 | 499 | return 0; |
2e5d9c85 | 500 | |
501 | /* Low ISA region is always mapped WB. No need to track */ | |
bcc643dc | 502 | if (is_ISA_range(start, end - 1)) |
2e5d9c85 | 503 | return 0; |
2e5d9c85 | 504 | |
be03d9e8 | 505 | is_range_ram = pat_pagerange_is_ram(start, end); |
f5841740 VP |
506 | if (is_range_ram == 1) { |
507 | ||
508 | spin_lock(&memtype_lock); | |
509 | err = free_ram_pages_type(start, end); | |
510 | spin_unlock(&memtype_lock); | |
511 | ||
512 | return err; | |
513 | } else if (is_range_ram < 0) { | |
9542ada8 | 514 | return -EINVAL; |
f5841740 | 515 | } |
9542ada8 | 516 | |
2e5d9c85 | 517 | spin_lock(&memtype_lock); |
335ef896 VP |
518 | |
519 | entry = memtype_rb_search(&memtype_rbroot, start); | |
520 | if (unlikely(entry == NULL)) | |
521 | goto unlock_ret; | |
522 | ||
523 | /* | |
524 | * Saved entry points to an entry with start same or less than what | |
525 | * we searched for. Now go through the list in both directions to look | |
526 | * for the entry that matches with both start and end, with list stored | |
527 | * in sorted start address | |
528 | */ | |
529 | saved_entry = entry; | |
dcb73bf4 | 530 | list_for_each_entry_from(entry, &memtype_list, nd) { |
ac97991e | 531 | if (entry->start == start && entry->end == end) { |
335ef896 VP |
532 | rb_erase(&entry->rb, &memtype_rbroot); |
533 | list_del(&entry->nd); | |
534 | kfree(entry); | |
535 | err = 0; | |
536 | break; | |
537 | } else if (entry->start > start) { | |
538 | break; | |
539 | } | |
540 | } | |
541 | ||
542 | if (!err) | |
543 | goto unlock_ret; | |
80c5e73d | 544 | |
335ef896 VP |
545 | entry = saved_entry; |
546 | list_for_each_entry_reverse(entry, &memtype_list, nd) { | |
547 | if (entry->start == start && entry->end == end) { | |
548 | rb_erase(&entry->rb, &memtype_rbroot); | |
ac97991e AH |
549 | list_del(&entry->nd); |
550 | kfree(entry); | |
2e5d9c85 | 551 | err = 0; |
552 | break; | |
335ef896 VP |
553 | } else if (entry->start < start) { |
554 | break; | |
2e5d9c85 | 555 | } |
556 | } | |
335ef896 | 557 | unlock_ret: |
2e5d9c85 | 558 | spin_unlock(&memtype_lock); |
559 | ||
560 | if (err) { | |
28eb559b | 561 | printk(KERN_INFO "%s:%d freeing invalid memtype %Lx-%Lx\n", |
2e5d9c85 | 562 | current->comm, current->pid, start, end); |
563 | } | |
6997ab49 | 564 | |
77b52b4c | 565 | dprintk("free_memtype request 0x%Lx-0x%Lx\n", start, end); |
ad2cde16 | 566 | |
2e5d9c85 | 567 | return err; |
568 | } | |
569 | ||
f0970c13 | 570 | |
637b86e7 VP |
571 | /** |
572 | * lookup_memtype - Looksup the memory type for a physical address | |
573 | * @paddr: physical address of which memory type needs to be looked up | |
574 | * | |
575 | * Only to be called when PAT is enabled | |
576 | * | |
577 | * Returns _PAGE_CACHE_WB, _PAGE_CACHE_WC, _PAGE_CACHE_UC_MINUS or | |
578 | * _PAGE_CACHE_UC | |
579 | */ | |
580 | static unsigned long lookup_memtype(u64 paddr) | |
581 | { | |
582 | int rettype = _PAGE_CACHE_WB; | |
583 | struct memtype *entry; | |
584 | ||
585 | if (is_ISA_range(paddr, paddr + PAGE_SIZE - 1)) | |
586 | return rettype; | |
587 | ||
588 | if (pat_pagerange_is_ram(paddr, paddr + PAGE_SIZE)) { | |
589 | struct page *page; | |
590 | spin_lock(&memtype_lock); | |
591 | page = pfn_to_page(paddr >> PAGE_SHIFT); | |
592 | rettype = get_page_memtype(page); | |
593 | spin_unlock(&memtype_lock); | |
594 | /* | |
595 | * -1 from get_page_memtype() implies RAM page is in its | |
596 | * default state and not reserved, and hence of type WB | |
597 | */ | |
598 | if (rettype == -1) | |
599 | rettype = _PAGE_CACHE_WB; | |
600 | ||
601 | return rettype; | |
602 | } | |
603 | ||
604 | spin_lock(&memtype_lock); | |
605 | ||
606 | entry = memtype_rb_search(&memtype_rbroot, paddr); | |
607 | if (entry != NULL) | |
608 | rettype = entry->type; | |
609 | else | |
610 | rettype = _PAGE_CACHE_UC_MINUS; | |
611 | ||
612 | spin_unlock(&memtype_lock); | |
613 | return rettype; | |
614 | } | |
615 | ||
9fd126bc VP |
616 | /** |
617 | * io_reserve_memtype - Request a memory type mapping for a region of memory | |
618 | * @start: start (physical address) of the region | |
619 | * @end: end (physical address) of the region | |
620 | * @type: A pointer to memtype, with requested type. On success, requested | |
621 | * or any other compatible type that was available for the region is returned | |
622 | * | |
623 | * On success, returns 0 | |
624 | * On failure, returns non-zero | |
625 | */ | |
626 | int io_reserve_memtype(resource_size_t start, resource_size_t end, | |
627 | unsigned long *type) | |
628 | { | |
b855192c | 629 | resource_size_t size = end - start; |
9fd126bc VP |
630 | unsigned long req_type = *type; |
631 | unsigned long new_type; | |
632 | int ret; | |
633 | ||
b855192c | 634 | WARN_ON_ONCE(iomem_map_sanity_check(start, size)); |
9fd126bc VP |
635 | |
636 | ret = reserve_memtype(start, end, req_type, &new_type); | |
637 | if (ret) | |
638 | goto out_err; | |
639 | ||
b855192c | 640 | if (!is_new_memtype_allowed(start, size, req_type, new_type)) |
9fd126bc VP |
641 | goto out_free; |
642 | ||
b855192c | 643 | if (kernel_map_sync_memtype(start, size, new_type) < 0) |
9fd126bc VP |
644 | goto out_free; |
645 | ||
646 | *type = new_type; | |
647 | return 0; | |
648 | ||
649 | out_free: | |
650 | free_memtype(start, end); | |
651 | ret = -EBUSY; | |
652 | out_err: | |
653 | return ret; | |
654 | } | |
655 | ||
656 | /** | |
657 | * io_free_memtype - Release a memory type mapping for a region of memory | |
658 | * @start: start (physical address) of the region | |
659 | * @end: end (physical address) of the region | |
660 | */ | |
661 | void io_free_memtype(resource_size_t start, resource_size_t end) | |
662 | { | |
663 | free_memtype(start, end); | |
664 | } | |
665 | ||
f0970c13 | 666 | pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, |
667 | unsigned long size, pgprot_t vma_prot) | |
668 | { | |
669 | return vma_prot; | |
670 | } | |
671 | ||
d092633b IM |
672 | #ifdef CONFIG_STRICT_DEVMEM |
673 | /* This check is done in drivers/char/mem.c in case of STRICT_DEVMEM*/ | |
0124cecf VP |
674 | static inline int range_is_allowed(unsigned long pfn, unsigned long size) |
675 | { | |
676 | return 1; | |
677 | } | |
678 | #else | |
9e41bff2 | 679 | /* This check is needed to avoid cache aliasing when PAT is enabled */ |
0124cecf VP |
680 | static inline int range_is_allowed(unsigned long pfn, unsigned long size) |
681 | { | |
682 | u64 from = ((u64)pfn) << PAGE_SHIFT; | |
683 | u64 to = from + size; | |
684 | u64 cursor = from; | |
685 | ||
9e41bff2 RT |
686 | if (!pat_enabled) |
687 | return 1; | |
688 | ||
0124cecf VP |
689 | while (cursor < to) { |
690 | if (!devmem_is_allowed(pfn)) { | |
691 | printk(KERN_INFO | |
692 | "Program %s tried to access /dev/mem between %Lx->%Lx.\n", | |
693 | current->comm, from, to); | |
694 | return 0; | |
695 | } | |
696 | cursor += PAGE_SIZE; | |
697 | pfn++; | |
698 | } | |
699 | return 1; | |
700 | } | |
d092633b | 701 | #endif /* CONFIG_STRICT_DEVMEM */ |
0124cecf | 702 | |
f0970c13 | 703 | int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn, |
704 | unsigned long size, pgprot_t *vma_prot) | |
705 | { | |
0c3c8a18 | 706 | unsigned long flags = _PAGE_CACHE_WB; |
f0970c13 | 707 | |
0124cecf VP |
708 | if (!range_is_allowed(pfn, size)) |
709 | return 0; | |
710 | ||
f0970c13 | 711 | if (file->f_flags & O_SYNC) { |
28df82eb | 712 | flags = _PAGE_CACHE_UC_MINUS; |
f0970c13 | 713 | } |
714 | ||
715 | #ifdef CONFIG_X86_32 | |
716 | /* | |
717 | * On the PPro and successors, the MTRRs are used to set | |
718 | * memory types for physical addresses outside main memory, | |
719 | * so blindly setting UC or PWT on those pages is wrong. | |
720 | * For Pentiums and earlier, the surround logic should disable | |
721 | * caching for the high addresses through the KEN pin, but | |
722 | * we maintain the tradition of paranoia in this code. | |
723 | */ | |
499f8f84 | 724 | if (!pat_enabled && |
cd7a4e93 AH |
725 | !(boot_cpu_has(X86_FEATURE_MTRR) || |
726 | boot_cpu_has(X86_FEATURE_K6_MTRR) || | |
727 | boot_cpu_has(X86_FEATURE_CYRIX_ARR) || | |
728 | boot_cpu_has(X86_FEATURE_CENTAUR_MCR)) && | |
729 | (pfn << PAGE_SHIFT) >= __pa(high_memory)) { | |
e7f260a2 | 730 | flags = _PAGE_CACHE_UC; |
f0970c13 | 731 | } |
732 | #endif | |
733 | ||
e7f260a2 | 734 | *vma_prot = __pgprot((pgprot_val(*vma_prot) & ~_PAGE_CACHE_MASK) | |
735 | flags); | |
f0970c13 | 736 | return 1; |
737 | } | |
e7f260a2 | 738 | |
7880f746 VP |
739 | /* |
740 | * Change the memory type for the physial address range in kernel identity | |
741 | * mapping space if that range is a part of identity map. | |
742 | */ | |
743 | int kernel_map_sync_memtype(u64 base, unsigned long size, unsigned long flags) | |
744 | { | |
745 | unsigned long id_sz; | |
746 | ||
5fc51746 | 747 | if (base >= __pa(high_memory)) |
7880f746 VP |
748 | return 0; |
749 | ||
750 | id_sz = (__pa(high_memory) < base + size) ? | |
751 | __pa(high_memory) - base : | |
752 | size; | |
753 | ||
754 | if (ioremap_change_attr((unsigned long)__va(base), id_sz, flags) < 0) { | |
755 | printk(KERN_INFO | |
756 | "%s:%d ioremap_change_attr failed %s " | |
757 | "for %Lx-%Lx\n", | |
758 | current->comm, current->pid, | |
759 | cattr_name(flags), | |
760 | base, (unsigned long long)(base + size)); | |
761 | return -EINVAL; | |
762 | } | |
763 | return 0; | |
764 | } | |
765 | ||
5899329b | 766 | /* |
767 | * Internal interface to reserve a range of physical memory with prot. | |
768 | * Reserved non RAM regions only and after successful reserve_memtype, | |
769 | * this func also keeps identity mapping (if any) in sync with this new prot. | |
770 | */ | |
cdecff68 | 771 | static int reserve_pfn_range(u64 paddr, unsigned long size, pgprot_t *vma_prot, |
772 | int strict_prot) | |
5899329b | 773 | { |
774 | int is_ram = 0; | |
7880f746 | 775 | int ret; |
cdecff68 | 776 | unsigned long want_flags = (pgprot_val(*vma_prot) & _PAGE_CACHE_MASK); |
0c3c8a18 | 777 | unsigned long flags = want_flags; |
5899329b | 778 | |
be03d9e8 | 779 | is_ram = pat_pagerange_is_ram(paddr, paddr + size); |
5899329b | 780 | |
be03d9e8 | 781 | /* |
d886c73c VP |
782 | * reserve_pfn_range() for RAM pages. We do not refcount to keep |
783 | * track of number of mappings of RAM pages. We can assert that | |
784 | * the type requested matches the type of first page in the range. | |
be03d9e8 | 785 | */ |
d886c73c VP |
786 | if (is_ram) { |
787 | if (!pat_enabled) | |
788 | return 0; | |
789 | ||
790 | flags = lookup_memtype(paddr); | |
791 | if (want_flags != flags) { | |
792 | printk(KERN_WARNING | |
793 | "%s:%d map pfn RAM range req %s for %Lx-%Lx, got %s\n", | |
794 | current->comm, current->pid, | |
795 | cattr_name(want_flags), | |
796 | (unsigned long long)paddr, | |
797 | (unsigned long long)(paddr + size), | |
798 | cattr_name(flags)); | |
799 | *vma_prot = __pgprot((pgprot_val(*vma_prot) & | |
800 | (~_PAGE_CACHE_MASK)) | | |
801 | flags); | |
802 | } | |
4bb9c5c0 | 803 | return 0; |
d886c73c | 804 | } |
5899329b | 805 | |
806 | ret = reserve_memtype(paddr, paddr + size, want_flags, &flags); | |
807 | if (ret) | |
808 | return ret; | |
809 | ||
810 | if (flags != want_flags) { | |
1adcaafe SS |
811 | if (strict_prot || |
812 | !is_new_memtype_allowed(paddr, size, want_flags, flags)) { | |
cdecff68 | 813 | free_memtype(paddr, paddr + size); |
814 | printk(KERN_ERR "%s:%d map pfn expected mapping type %s" | |
815 | " for %Lx-%Lx, got %s\n", | |
816 | current->comm, current->pid, | |
817 | cattr_name(want_flags), | |
818 | (unsigned long long)paddr, | |
819 | (unsigned long long)(paddr + size), | |
820 | cattr_name(flags)); | |
821 | return -EINVAL; | |
822 | } | |
823 | /* | |
824 | * We allow returning different type than the one requested in | |
825 | * non strict case. | |
826 | */ | |
827 | *vma_prot = __pgprot((pgprot_val(*vma_prot) & | |
828 | (~_PAGE_CACHE_MASK)) | | |
829 | flags); | |
5899329b | 830 | } |
831 | ||
7880f746 | 832 | if (kernel_map_sync_memtype(paddr, size, flags) < 0) { |
5899329b | 833 | free_memtype(paddr, paddr + size); |
5899329b | 834 | return -EINVAL; |
835 | } | |
836 | return 0; | |
837 | } | |
838 | ||
839 | /* | |
840 | * Internal interface to free a range of physical memory. | |
841 | * Frees non RAM regions only. | |
842 | */ | |
843 | static void free_pfn_range(u64 paddr, unsigned long size) | |
844 | { | |
845 | int is_ram; | |
846 | ||
be03d9e8 | 847 | is_ram = pat_pagerange_is_ram(paddr, paddr + size); |
5899329b | 848 | if (is_ram == 0) |
849 | free_memtype(paddr, paddr + size); | |
850 | } | |
851 | ||
852 | /* | |
853 | * track_pfn_vma_copy is called when vma that is covering the pfnmap gets | |
854 | * copied through copy_page_range(). | |
855 | * | |
856 | * If the vma has a linear pfn mapping for the entire range, we get the prot | |
857 | * from pte and reserve the entire vma range with single reserve_pfn_range call. | |
5899329b | 858 | */ |
859 | int track_pfn_vma_copy(struct vm_area_struct *vma) | |
860 | { | |
c1c15b65 | 861 | resource_size_t paddr; |
982d789a | 862 | unsigned long prot; |
4b065046 | 863 | unsigned long vma_size = vma->vm_end - vma->vm_start; |
cdecff68 | 864 | pgprot_t pgprot; |
5899329b | 865 | |
5899329b | 866 | if (is_linear_pfn_mapping(vma)) { |
867 | /* | |
982d789a | 868 | * reserve the whole chunk covered by vma. We need the |
869 | * starting address and protection from pte. | |
5899329b | 870 | */ |
4b065046 | 871 | if (follow_phys(vma, vma->vm_start, 0, &prot, &paddr)) { |
5899329b | 872 | WARN_ON_ONCE(1); |
982d789a | 873 | return -EINVAL; |
5899329b | 874 | } |
cdecff68 | 875 | pgprot = __pgprot(prot); |
876 | return reserve_pfn_range(paddr, vma_size, &pgprot, 1); | |
5899329b | 877 | } |
878 | ||
5899329b | 879 | return 0; |
5899329b | 880 | } |
881 | ||
882 | /* | |
883 | * track_pfn_vma_new is called when a _new_ pfn mapping is being established | |
884 | * for physical range indicated by pfn and size. | |
885 | * | |
886 | * prot is passed in as a parameter for the new mapping. If the vma has a | |
887 | * linear pfn mapping for the entire range reserve the entire vma range with | |
888 | * single reserve_pfn_range call. | |
5899329b | 889 | */ |
e4b866ed | 890 | int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t *prot, |
5899329b | 891 | unsigned long pfn, unsigned long size) |
892 | { | |
10876376 | 893 | unsigned long flags; |
c1c15b65 | 894 | resource_size_t paddr; |
4b065046 | 895 | unsigned long vma_size = vma->vm_end - vma->vm_start; |
5899329b | 896 | |
5899329b | 897 | if (is_linear_pfn_mapping(vma)) { |
898 | /* reserve the whole chunk starting from vm_pgoff */ | |
c1c15b65 | 899 | paddr = (resource_size_t)vma->vm_pgoff << PAGE_SHIFT; |
cdecff68 | 900 | return reserve_pfn_range(paddr, vma_size, prot, 0); |
5899329b | 901 | } |
902 | ||
10876376 VP |
903 | if (!pat_enabled) |
904 | return 0; | |
905 | ||
906 | /* for vm_insert_pfn and friends, we set prot based on lookup */ | |
907 | flags = lookup_memtype(pfn << PAGE_SHIFT); | |
908 | *prot = __pgprot((pgprot_val(vma->vm_page_prot) & (~_PAGE_CACHE_MASK)) | | |
909 | flags); | |
910 | ||
5899329b | 911 | return 0; |
5899329b | 912 | } |
913 | ||
914 | /* | |
915 | * untrack_pfn_vma is called while unmapping a pfnmap for a region. | |
916 | * untrack can be called for a specific region indicated by pfn and size or | |
917 | * can be for the entire vma (in which case size can be zero). | |
918 | */ | |
919 | void untrack_pfn_vma(struct vm_area_struct *vma, unsigned long pfn, | |
920 | unsigned long size) | |
921 | { | |
c1c15b65 | 922 | resource_size_t paddr; |
4b065046 | 923 | unsigned long vma_size = vma->vm_end - vma->vm_start; |
5899329b | 924 | |
5899329b | 925 | if (is_linear_pfn_mapping(vma)) { |
926 | /* free the whole chunk starting from vm_pgoff */ | |
c1c15b65 | 927 | paddr = (resource_size_t)vma->vm_pgoff << PAGE_SHIFT; |
5899329b | 928 | free_pfn_range(paddr, vma_size); |
929 | return; | |
930 | } | |
5899329b | 931 | } |
932 | ||
2520bd31 | 933 | pgprot_t pgprot_writecombine(pgprot_t prot) |
934 | { | |
935 | if (pat_enabled) | |
936 | return __pgprot(pgprot_val(prot) | _PAGE_CACHE_WC); | |
937 | else | |
938 | return pgprot_noncached(prot); | |
939 | } | |
92b9af9e | 940 | EXPORT_SYMBOL_GPL(pgprot_writecombine); |
2520bd31 | 941 | |
012f09e7 | 942 | #if defined(CONFIG_DEBUG_FS) && defined(CONFIG_X86_PAT) |
fec0962e | 943 | |
944 | /* get Nth element of the linked list */ | |
945 | static struct memtype *memtype_get_idx(loff_t pos) | |
946 | { | |
947 | struct memtype *list_node, *print_entry; | |
948 | int i = 1; | |
949 | ||
950 | print_entry = kmalloc(sizeof(struct memtype), GFP_KERNEL); | |
951 | if (!print_entry) | |
952 | return NULL; | |
953 | ||
954 | spin_lock(&memtype_lock); | |
955 | list_for_each_entry(list_node, &memtype_list, nd) { | |
956 | if (pos == i) { | |
957 | *print_entry = *list_node; | |
958 | spin_unlock(&memtype_lock); | |
959 | return print_entry; | |
960 | } | |
961 | ++i; | |
962 | } | |
963 | spin_unlock(&memtype_lock); | |
964 | kfree(print_entry); | |
ad2cde16 | 965 | |
fec0962e | 966 | return NULL; |
967 | } | |
968 | ||
969 | static void *memtype_seq_start(struct seq_file *seq, loff_t *pos) | |
970 | { | |
971 | if (*pos == 0) { | |
972 | ++*pos; | |
973 | seq_printf(seq, "PAT memtype list:\n"); | |
974 | } | |
975 | ||
976 | return memtype_get_idx(*pos); | |
977 | } | |
978 | ||
979 | static void *memtype_seq_next(struct seq_file *seq, void *v, loff_t *pos) | |
980 | { | |
981 | ++*pos; | |
982 | return memtype_get_idx(*pos); | |
983 | } | |
984 | ||
985 | static void memtype_seq_stop(struct seq_file *seq, void *v) | |
986 | { | |
987 | } | |
988 | ||
989 | static int memtype_seq_show(struct seq_file *seq, void *v) | |
990 | { | |
991 | struct memtype *print_entry = (struct memtype *)v; | |
992 | ||
993 | seq_printf(seq, "%s @ 0x%Lx-0x%Lx\n", cattr_name(print_entry->type), | |
994 | print_entry->start, print_entry->end); | |
995 | kfree(print_entry); | |
ad2cde16 | 996 | |
fec0962e | 997 | return 0; |
998 | } | |
999 | ||
d535e431 | 1000 | static const struct seq_operations memtype_seq_ops = { |
fec0962e | 1001 | .start = memtype_seq_start, |
1002 | .next = memtype_seq_next, | |
1003 | .stop = memtype_seq_stop, | |
1004 | .show = memtype_seq_show, | |
1005 | }; | |
1006 | ||
1007 | static int memtype_seq_open(struct inode *inode, struct file *file) | |
1008 | { | |
1009 | return seq_open(file, &memtype_seq_ops); | |
1010 | } | |
1011 | ||
1012 | static const struct file_operations memtype_fops = { | |
1013 | .open = memtype_seq_open, | |
1014 | .read = seq_read, | |
1015 | .llseek = seq_lseek, | |
1016 | .release = seq_release, | |
1017 | }; | |
1018 | ||
1019 | static int __init pat_memtype_list_init(void) | |
1020 | { | |
1021 | debugfs_create_file("pat_memtype_list", S_IRUSR, arch_debugfs_dir, | |
1022 | NULL, &memtype_fops); | |
1023 | return 0; | |
1024 | } | |
1025 | ||
1026 | late_initcall(pat_memtype_list_init); | |
1027 | ||
012f09e7 | 1028 | #endif /* CONFIG_DEBUG_FS && CONFIG_X86_PAT */ |