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867e359b CM |
1 | /* |
2 | * Copyright 2010 Tilera Corporation. All Rights Reserved. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public License | |
6 | * as published by the Free Software Foundation, version 2. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, but | |
9 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or | |
11 | * NON INFRINGEMENT. See the GNU General Public License for | |
12 | * more details. | |
13 | * | |
14 | * This code maintains the "home" for each page in the system. | |
15 | */ | |
16 | ||
17 | #include <linux/kernel.h> | |
18 | #include <linux/mm.h> | |
19 | #include <linux/spinlock.h> | |
20 | #include <linux/list.h> | |
21 | #include <linux/bootmem.h> | |
22 | #include <linux/rmap.h> | |
23 | #include <linux/pagemap.h> | |
24 | #include <linux/mutex.h> | |
25 | #include <linux/interrupt.h> | |
26 | #include <linux/sysctl.h> | |
27 | #include <linux/pagevec.h> | |
28 | #include <linux/ptrace.h> | |
29 | #include <linux/timex.h> | |
30 | #include <linux/cache.h> | |
31 | #include <linux/smp.h> | |
c745a8a1 | 32 | #include <linux/module.h> |
621b1955 | 33 | #include <linux/hugetlb.h> |
867e359b CM |
34 | |
35 | #include <asm/page.h> | |
36 | #include <asm/sections.h> | |
37 | #include <asm/tlbflush.h> | |
38 | #include <asm/pgalloc.h> | |
39 | #include <asm/homecache.h> | |
40 | ||
bf65e440 CM |
41 | #include <arch/sim.h> |
42 | ||
867e359b CM |
43 | #include "migrate.h" |
44 | ||
45 | ||
867e359b CM |
46 | /* |
47 | * The noallocl2 option suppresses all use of the L2 cache to cache | |
d7c96611 | 48 | * locally from a remote home. |
867e359b | 49 | */ |
0707ad30 | 50 | static int __write_once noallocl2; |
867e359b CM |
51 | static int __init set_noallocl2(char *str) |
52 | { | |
53 | noallocl2 = 1; | |
54 | return 0; | |
55 | } | |
56 | early_param("noallocl2", set_noallocl2); | |
57 | ||
867e359b | 58 | |
867e359b CM |
59 | /* |
60 | * Update the irq_stat for cpus that we are going to interrupt | |
61 | * with TLB or cache flushes. Also handle removing dataplane cpus | |
62 | * from the TLB flush set, and setting dataplane_tlb_state instead. | |
63 | */ | |
64 | static void hv_flush_update(const struct cpumask *cache_cpumask, | |
65 | struct cpumask *tlb_cpumask, | |
66 | unsigned long tlb_va, unsigned long tlb_length, | |
67 | HV_Remote_ASID *asids, int asidcount) | |
68 | { | |
69 | struct cpumask mask; | |
70 | int i, cpu; | |
71 | ||
72 | cpumask_clear(&mask); | |
73 | if (cache_cpumask) | |
74 | cpumask_or(&mask, &mask, cache_cpumask); | |
75 | if (tlb_cpumask && tlb_length) { | |
76 | cpumask_or(&mask, &mask, tlb_cpumask); | |
77 | } | |
78 | ||
79 | for (i = 0; i < asidcount; ++i) | |
80 | cpumask_set_cpu(asids[i].y * smp_width + asids[i].x, &mask); | |
81 | ||
82 | /* | |
83 | * Don't bother to update atomically; losing a count | |
84 | * here is not that critical. | |
85 | */ | |
86 | for_each_cpu(cpu, &mask) | |
87 | ++per_cpu(irq_stat, cpu).irq_hv_flush_count; | |
88 | } | |
89 | ||
90 | /* | |
91 | * This wrapper function around hv_flush_remote() does several things: | |
92 | * | |
93 | * - Provides a return value error-checking panic path, since | |
94 | * there's never any good reason for hv_flush_remote() to fail. | |
95 | * - Accepts a 32-bit PFN rather than a 64-bit PA, which generally | |
96 | * is the type that Linux wants to pass around anyway. | |
867e359b CM |
97 | * - Canonicalizes that lengths of zero make cpumasks NULL. |
98 | * - Handles deferring TLB flushes for dataplane tiles. | |
99 | * - Tracks remote interrupts in the per-cpu irq_cpustat_t. | |
100 | * | |
101 | * Note that we have to wait until the cache flush completes before | |
102 | * updating the per-cpu last_cache_flush word, since otherwise another | |
103 | * concurrent flush can race, conclude the flush has already | |
104 | * completed, and start to use the page while it's still dirty | |
105 | * remotely (running concurrently with the actual evict, presumably). | |
106 | */ | |
107 | void flush_remote(unsigned long cache_pfn, unsigned long cache_control, | |
108 | const struct cpumask *cache_cpumask_orig, | |
109 | HV_VirtAddr tlb_va, unsigned long tlb_length, | |
110 | unsigned long tlb_pgsize, | |
111 | const struct cpumask *tlb_cpumask_orig, | |
112 | HV_Remote_ASID *asids, int asidcount) | |
113 | { | |
114 | int rc; | |
867e359b CM |
115 | struct cpumask cache_cpumask_copy, tlb_cpumask_copy; |
116 | struct cpumask *cache_cpumask, *tlb_cpumask; | |
117 | HV_PhysAddr cache_pa; | |
118 | char cache_buf[NR_CPUS*5], tlb_buf[NR_CPUS*5]; | |
119 | ||
120 | mb(); /* provided just to simplify "magic hypervisor" mode */ | |
121 | ||
122 | /* | |
123 | * Canonicalize and copy the cpumasks. | |
124 | */ | |
125 | if (cache_cpumask_orig && cache_control) { | |
126 | cpumask_copy(&cache_cpumask_copy, cache_cpumask_orig); | |
127 | cache_cpumask = &cache_cpumask_copy; | |
128 | } else { | |
129 | cpumask_clear(&cache_cpumask_copy); | |
130 | cache_cpumask = NULL; | |
131 | } | |
132 | if (cache_cpumask == NULL) | |
133 | cache_control = 0; | |
134 | if (tlb_cpumask_orig && tlb_length) { | |
135 | cpumask_copy(&tlb_cpumask_copy, tlb_cpumask_orig); | |
136 | tlb_cpumask = &tlb_cpumask_copy; | |
137 | } else { | |
138 | cpumask_clear(&tlb_cpumask_copy); | |
139 | tlb_cpumask = NULL; | |
140 | } | |
141 | ||
142 | hv_flush_update(cache_cpumask, tlb_cpumask, tlb_va, tlb_length, | |
143 | asids, asidcount); | |
144 | cache_pa = (HV_PhysAddr)cache_pfn << PAGE_SHIFT; | |
867e359b CM |
145 | rc = hv_flush_remote(cache_pa, cache_control, |
146 | cpumask_bits(cache_cpumask), | |
147 | tlb_va, tlb_length, tlb_pgsize, | |
148 | cpumask_bits(tlb_cpumask), | |
149 | asids, asidcount); | |
867e359b CM |
150 | if (rc == 0) |
151 | return; | |
152 | cpumask_scnprintf(cache_buf, sizeof(cache_buf), &cache_cpumask_copy); | |
153 | cpumask_scnprintf(tlb_buf, sizeof(tlb_buf), &tlb_cpumask_copy); | |
154 | ||
0707ad30 | 155 | pr_err("hv_flush_remote(%#llx, %#lx, %p [%s]," |
867e359b CM |
156 | " %#lx, %#lx, %#lx, %p [%s], %p, %d) = %d\n", |
157 | cache_pa, cache_control, cache_cpumask, cache_buf, | |
158 | (unsigned long)tlb_va, tlb_length, tlb_pgsize, | |
159 | tlb_cpumask, tlb_buf, | |
160 | asids, asidcount, rc); | |
867e359b CM |
161 | panic("Unsafe to continue."); |
162 | } | |
163 | ||
bbaa22c3 | 164 | static void homecache_finv_page_va(void* va, int home) |
63b7ca6b | 165 | { |
bc1a298f CM |
166 | int cpu = get_cpu(); |
167 | if (home == cpu) { | |
bbaa22c3 CM |
168 | finv_buffer_local(va, PAGE_SIZE); |
169 | } else if (home == PAGE_HOME_HASH) { | |
170 | finv_buffer_remote(va, PAGE_SIZE, 1); | |
171 | } else { | |
172 | BUG_ON(home < 0 || home >= NR_CPUS); | |
173 | finv_buffer_remote(va, PAGE_SIZE, 0); | |
63b7ca6b | 174 | } |
bc1a298f | 175 | put_cpu(); |
63b7ca6b CM |
176 | } |
177 | ||
bbaa22c3 | 178 | void homecache_finv_map_page(struct page *page, int home) |
867e359b | 179 | { |
bbaa22c3 CM |
180 | unsigned long flags; |
181 | unsigned long va; | |
182 | pte_t *ptep; | |
183 | pte_t pte; | |
184 | ||
185 | if (home == PAGE_HOME_UNCACHED) | |
186 | return; | |
187 | local_irq_save(flags); | |
188 | #ifdef CONFIG_HIGHMEM | |
189 | va = __fix_to_virt(FIX_KMAP_BEGIN + kmap_atomic_idx_push() + | |
190 | (KM_TYPE_NR * smp_processor_id())); | |
191 | #else | |
192 | va = __fix_to_virt(FIX_HOMECACHE_BEGIN + smp_processor_id()); | |
193 | #endif | |
640710a3 | 194 | ptep = virt_to_kpte(va); |
bbaa22c3 CM |
195 | pte = pfn_pte(page_to_pfn(page), PAGE_KERNEL); |
196 | __set_pte(ptep, pte_set_home(pte, home)); | |
197 | homecache_finv_page_va((void *)va, home); | |
198 | __pte_clear(ptep); | |
199 | hv_flush_page(va, PAGE_SIZE); | |
200 | #ifdef CONFIG_HIGHMEM | |
201 | kmap_atomic_idx_pop(); | |
202 | #endif | |
203 | local_irq_restore(flags); | |
867e359b CM |
204 | } |
205 | ||
bbaa22c3 | 206 | static void homecache_finv_page_home(struct page *page, int home) |
867e359b | 207 | { |
bbaa22c3 CM |
208 | if (!PageHighMem(page) && home == page_home(page)) |
209 | homecache_finv_page_va(page_address(page), home); | |
210 | else | |
211 | homecache_finv_map_page(page, home); | |
867e359b CM |
212 | } |
213 | ||
bbaa22c3 | 214 | static inline bool incoherent_home(int home) |
867e359b | 215 | { |
bbaa22c3 | 216 | return home == PAGE_HOME_IMMUTABLE || home == PAGE_HOME_INCOHERENT; |
867e359b CM |
217 | } |
218 | ||
bbaa22c3 | 219 | static void homecache_finv_page_internal(struct page *page, int force_map) |
867e359b | 220 | { |
bbaa22c3 CM |
221 | int home = page_home(page); |
222 | if (home == PAGE_HOME_UNCACHED) | |
223 | return; | |
224 | if (incoherent_home(home)) { | |
225 | int cpu; | |
226 | for_each_cpu(cpu, &cpu_cacheable_map) | |
227 | homecache_finv_map_page(page, cpu); | |
228 | } else if (force_map) { | |
229 | /* Force if, e.g., the normal mapping is migrating. */ | |
230 | homecache_finv_map_page(page, home); | |
231 | } else { | |
232 | homecache_finv_page_home(page, home); | |
233 | } | |
234 | sim_validate_lines_evicted(PFN_PHYS(page_to_pfn(page)), PAGE_SIZE); | |
867e359b CM |
235 | } |
236 | ||
bbaa22c3 CM |
237 | void homecache_finv_page(struct page *page) |
238 | { | |
239 | homecache_finv_page_internal(page, 0); | |
240 | } | |
241 | ||
242 | void homecache_evict(const struct cpumask *mask) | |
243 | { | |
244 | flush_remote(0, HV_FLUSH_EVICT_L2, mask, 0, 0, 0, NULL, NULL, 0); | |
245 | } | |
867e359b CM |
246 | |
247 | /* Report the home corresponding to a given PTE. */ | |
248 | static int pte_to_home(pte_t pte) | |
249 | { | |
250 | if (hv_pte_get_nc(pte)) | |
251 | return PAGE_HOME_IMMUTABLE; | |
252 | switch (hv_pte_get_mode(pte)) { | |
253 | case HV_PTE_MODE_CACHE_TILE_L3: | |
254 | return get_remote_cache_cpu(pte); | |
255 | case HV_PTE_MODE_CACHE_NO_L3: | |
256 | return PAGE_HOME_INCOHERENT; | |
257 | case HV_PTE_MODE_UNCACHED: | |
258 | return PAGE_HOME_UNCACHED; | |
867e359b CM |
259 | case HV_PTE_MODE_CACHE_HASH_L3: |
260 | return PAGE_HOME_HASH; | |
867e359b CM |
261 | } |
262 | panic("Bad PTE %#llx\n", pte.val); | |
263 | } | |
264 | ||
265 | /* Update the home of a PTE if necessary (can also be used for a pgprot_t). */ | |
266 | pte_t pte_set_home(pte_t pte, int home) | |
267 | { | |
268 | /* Check for non-linear file mapping "PTEs" and pass them through. */ | |
269 | if (pte_file(pte)) | |
270 | return pte; | |
271 | ||
272 | #if CHIP_HAS_MMIO() | |
273 | /* Check for MMIO mappings and pass them through. */ | |
274 | if (hv_pte_get_mode(pte) == HV_PTE_MODE_MMIO) | |
275 | return pte; | |
276 | #endif | |
277 | ||
278 | ||
279 | /* | |
280 | * Only immutable pages get NC mappings. If we have a | |
281 | * non-coherent PTE, but the underlying page is not | |
282 | * immutable, it's likely the result of a forced | |
283 | * caching setting running up against ptrace setting | |
284 | * the page to be writable underneath. In this case, | |
285 | * just keep the PTE coherent. | |
286 | */ | |
287 | if (hv_pte_get_nc(pte) && home != PAGE_HOME_IMMUTABLE) { | |
288 | pte = hv_pte_clear_nc(pte); | |
0707ad30 | 289 | pr_err("non-immutable page incoherently referenced: %#llx\n", |
867e359b CM |
290 | pte.val); |
291 | } | |
292 | ||
293 | switch (home) { | |
294 | ||
295 | case PAGE_HOME_UNCACHED: | |
296 | pte = hv_pte_set_mode(pte, HV_PTE_MODE_UNCACHED); | |
297 | break; | |
298 | ||
299 | case PAGE_HOME_INCOHERENT: | |
300 | pte = hv_pte_set_mode(pte, HV_PTE_MODE_CACHE_NO_L3); | |
301 | break; | |
302 | ||
303 | case PAGE_HOME_IMMUTABLE: | |
304 | /* | |
305 | * We could home this page anywhere, since it's immutable, | |
306 | * but by default just home it to follow "hash_default". | |
307 | */ | |
308 | BUG_ON(hv_pte_get_writable(pte)); | |
309 | if (pte_get_forcecache(pte)) { | |
310 | /* Upgrade "force any cpu" to "No L3" for immutable. */ | |
311 | if (hv_pte_get_mode(pte) == HV_PTE_MODE_CACHE_TILE_L3 | |
312 | && pte_get_anyhome(pte)) { | |
313 | pte = hv_pte_set_mode(pte, | |
314 | HV_PTE_MODE_CACHE_NO_L3); | |
315 | } | |
316 | } else | |
867e359b CM |
317 | if (hash_default) |
318 | pte = hv_pte_set_mode(pte, HV_PTE_MODE_CACHE_HASH_L3); | |
319 | else | |
867e359b CM |
320 | pte = hv_pte_set_mode(pte, HV_PTE_MODE_CACHE_NO_L3); |
321 | pte = hv_pte_set_nc(pte); | |
322 | break; | |
323 | ||
867e359b CM |
324 | case PAGE_HOME_HASH: |
325 | pte = hv_pte_set_mode(pte, HV_PTE_MODE_CACHE_HASH_L3); | |
326 | break; | |
867e359b CM |
327 | |
328 | default: | |
329 | BUG_ON(home < 0 || home >= NR_CPUS || | |
330 | !cpu_is_valid_lotar(home)); | |
331 | pte = hv_pte_set_mode(pte, HV_PTE_MODE_CACHE_TILE_L3); | |
332 | pte = set_remote_cache_cpu(pte, home); | |
333 | break; | |
334 | } | |
335 | ||
867e359b CM |
336 | if (noallocl2) |
337 | pte = hv_pte_set_no_alloc_l2(pte); | |
338 | ||
339 | /* Simplify "no local and no l3" to "uncached" */ | |
340 | if (hv_pte_get_no_alloc_l2(pte) && hv_pte_get_no_alloc_l1(pte) && | |
341 | hv_pte_get_mode(pte) == HV_PTE_MODE_CACHE_NO_L3) { | |
342 | pte = hv_pte_set_mode(pte, HV_PTE_MODE_UNCACHED); | |
343 | } | |
867e359b CM |
344 | |
345 | /* Checking this case here gives a better panic than from the hv. */ | |
346 | BUG_ON(hv_pte_get_mode(pte) == 0); | |
347 | ||
348 | return pte; | |
349 | } | |
c745a8a1 | 350 | EXPORT_SYMBOL(pte_set_home); |
867e359b CM |
351 | |
352 | /* | |
353 | * The routines in this section are the "static" versions of the normal | |
354 | * dynamic homecaching routines; they just set the home cache | |
355 | * of a kernel page once, and require a full-chip cache/TLB flush, | |
356 | * so they're not suitable for anything but infrequent use. | |
357 | */ | |
358 | ||
867e359b CM |
359 | int page_home(struct page *page) |
360 | { | |
361 | if (PageHighMem(page)) { | |
d7c96611 | 362 | return PAGE_HOME_HASH; |
867e359b CM |
363 | } else { |
364 | unsigned long kva = (unsigned long)page_address(page); | |
640710a3 | 365 | return pte_to_home(*virt_to_kpte(kva)); |
867e359b CM |
366 | } |
367 | } | |
e81510e0 | 368 | EXPORT_SYMBOL(page_home); |
867e359b CM |
369 | |
370 | void homecache_change_page_home(struct page *page, int order, int home) | |
371 | { | |
372 | int i, pages = (1 << order); | |
373 | unsigned long kva; | |
374 | ||
375 | BUG_ON(PageHighMem(page)); | |
376 | BUG_ON(page_count(page) > 1); | |
377 | BUG_ON(page_mapcount(page) != 0); | |
378 | kva = (unsigned long) page_address(page); | |
379 | flush_remote(0, HV_FLUSH_EVICT_L2, &cpu_cacheable_map, | |
380 | kva, pages * PAGE_SIZE, PAGE_SIZE, cpu_online_mask, | |
381 | NULL, 0); | |
382 | ||
383 | for (i = 0; i < pages; ++i, kva += PAGE_SIZE) { | |
640710a3 | 384 | pte_t *ptep = virt_to_kpte(kva); |
867e359b CM |
385 | pte_t pteval = *ptep; |
386 | BUG_ON(!pte_present(pteval) || pte_huge(pteval)); | |
76c567fb | 387 | __set_pte(ptep, pte_set_home(pteval, home)); |
867e359b CM |
388 | } |
389 | } | |
7c63e1ee | 390 | EXPORT_SYMBOL(homecache_change_page_home); |
867e359b CM |
391 | |
392 | struct page *homecache_alloc_pages(gfp_t gfp_mask, | |
393 | unsigned int order, int home) | |
394 | { | |
395 | struct page *page; | |
396 | BUG_ON(gfp_mask & __GFP_HIGHMEM); /* must be lowmem */ | |
397 | page = alloc_pages(gfp_mask, order); | |
398 | if (page) | |
399 | homecache_change_page_home(page, order, home); | |
400 | return page; | |
401 | } | |
c745a8a1 | 402 | EXPORT_SYMBOL(homecache_alloc_pages); |
867e359b CM |
403 | |
404 | struct page *homecache_alloc_pages_node(int nid, gfp_t gfp_mask, | |
405 | unsigned int order, int home) | |
406 | { | |
407 | struct page *page; | |
408 | BUG_ON(gfp_mask & __GFP_HIGHMEM); /* must be lowmem */ | |
409 | page = alloc_pages_node(nid, gfp_mask, order); | |
410 | if (page) | |
411 | homecache_change_page_home(page, order, home); | |
412 | return page; | |
413 | } | |
414 | ||
bbaa22c3 | 415 | void __homecache_free_pages(struct page *page, unsigned int order) |
867e359b | 416 | { |
867e359b | 417 | if (put_page_testzero(page)) { |
d7c96611 | 418 | homecache_change_page_home(page, order, PAGE_HOME_HASH); |
c2851a9b | 419 | if (order == 0) { |
b745bc85 | 420 | free_hot_cold_page(page, false); |
c2851a9b CM |
421 | } else { |
422 | init_page_count(page); | |
423 | __free_pages(page, order); | |
424 | } | |
867e359b CM |
425 | } |
426 | } | |
bbaa22c3 CM |
427 | EXPORT_SYMBOL(__homecache_free_pages); |
428 | ||
429 | void homecache_free_pages(unsigned long addr, unsigned int order) | |
430 | { | |
431 | if (addr != 0) { | |
432 | VM_BUG_ON(!virt_addr_valid((void *)addr)); | |
433 | __homecache_free_pages(virt_to_page((void *)addr), order); | |
434 | } | |
435 | } | |
436 | EXPORT_SYMBOL(homecache_free_pages); |