2 * ARC700 VIPT Cache Management
4 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
10 * vineetg: May 2011: for Non-aliasing VIPT D-cache following can be NOPs
11 * -flush_cache_dup_mm (fork)
12 * -likewise for flush_cache_mm (exit/execve)
13 * -likewise for flush_cache_range,flush_cache_page (munmap, exit, COW-break)
16 * -Now that MMU can support larger pg sz (16K), the determiniation of
17 * aliasing shd not be based on assumption of 8k pg
20 * -optimised version of flush_icache_range( ) for making I/D coherent
21 * when vaddr is available (agnostic of num of aliases)
24 * -Added documentation about I-cache aliasing on ARC700 and the way it
25 * was handled up until MMU V2.
26 * -Spotted a three year old bug when killing the 4 aliases, which needs
27 * bottom 2 bits, so we need to do paddr | {0x00, 0x01, 0x02, 0x03}
28 * instead of paddr | {0x00, 0x01, 0x10, 0x11}
29 * (Rajesh you owe me one now)
32 * -Off-by-one error when computing num_of_lines to flush
33 * This broke signal handling with bionic which uses synthetic sigret stub
36 * -GCC can't generate ZOL for core cache flush loops.
37 * Conv them into iterations based as opposed to while (start < end) types
40 * -In I-cache flush routine we used to chk for aliasing for every line INV.
41 * Instead now we setup routines per cache geometry and invoke them
42 * via function pointers.
45 * -Cache Line flush routines used to flush an extra line beyond end addr
46 * because check was while (end >= start) instead of (end > start)
47 * =Some call sites had to work around by doing -1, -4 etc to end param
48 * =Some callers didnt care. This was spec bad in case of INV routines
49 * which would discard valid data (cause of the horrible ext2 bug
52 * vineetg: June 11th 2008: Fixed flush_icache_range( )
53 * -Since ARC700 caches are not coherent (I$ doesnt snoop D$) both need
54 * to be flushed, which it was not doing.
55 * -load_module( ) passes vmalloc addr (Kernel Virtual Addr) to the API,
56 * however ARC cache maintenance OPs require PHY addr. Thus need to do
58 * -Also added optimisation there, that for range > PAGE SIZE we flush the
59 * entire cache in one shot rather than line by line. For e.g. a module
60 * with Code sz 600k, old code flushed 600k worth of cache (line-by-line),
61 * while cache is only 16 or 32k.
64 #include <linux/module.h>
66 #include <linux/sched.h>
67 #include <linux/cache.h>
68 #include <linux/mmu_context.h>
69 #include <linux/syscalls.h>
70 #include <linux/uaccess.h>
71 #include <linux/pagemap.h>
72 #include <asm/cacheflush.h>
73 #include <asm/cachectl.h>
74 #include <asm/setup.h>
76 /* Instruction cache related Auxiliary registers */
77 #define ARC_REG_IC_BCR 0x77 /* Build Config reg */
78 #define ARC_REG_IC_IVIC 0x10
79 #define ARC_REG_IC_CTRL 0x11
80 #define ARC_REG_IC_IVIL 0x19
81 #if (CONFIG_ARC_MMU_VER > 2)
82 #define ARC_REG_IC_PTAG 0x1E
85 /* Bit val in IC_CTRL */
86 #define IC_CTRL_CACHE_DISABLE 0x1
88 /* Data cache related Auxiliary registers */
89 #define ARC_REG_DC_BCR 0x72 /* Build Config reg */
90 #define ARC_REG_DC_IVDC 0x47
91 #define ARC_REG_DC_CTRL 0x48
92 #define ARC_REG_DC_IVDL 0x4A
93 #define ARC_REG_DC_FLSH 0x4B
94 #define ARC_REG_DC_FLDL 0x4C
95 #if (CONFIG_ARC_MMU_VER > 2)
96 #define ARC_REG_DC_PTAG 0x5C
99 /* Bit val in DC_CTRL */
100 #define DC_CTRL_INV_MODE_FLUSH 0x40
101 #define DC_CTRL_FLUSH_STATUS 0x100
103 char *arc_cache_mumbojumbo(int cpu_id, char *buf, int len)
106 unsigned int c = smp_processor_id();
108 #define PR_CACHE(p, enb, str) \
111 n += scnprintf(buf + n, len - n, str"\t\t: N/A\n"); \
113 n += scnprintf(buf + n, len - n, \
114 str"\t\t: (%uK) VIPT, %dway set-asc, %ub Line %s\n", \
115 TO_KB((p)->sz), (p)->assoc, (p)->line_len, \
116 enb ? "" : "DISABLED (kernel-build)"); \
119 PR_CACHE(&cpuinfo_arc700[c].icache, IS_ENABLED(CONFIG_ARC_HAS_ICACHE),
121 PR_CACHE(&cpuinfo_arc700[c].dcache, IS_ENABLED(CONFIG_ARC_HAS_DCACHE),
128 * Read the Cache Build Confuration Registers, Decode them and save into
129 * the cpuinfo structure for later use.
130 * No Validation done here, simply read/convert the BCRs
132 void read_decode_cache_bcr(void)
134 struct cpuinfo_arc_cache *p_ic, *p_dc;
135 unsigned int cpu = smp_processor_id();
137 #ifdef CONFIG_CPU_BIG_ENDIAN
138 unsigned int pad:12, line_len:4, sz:4, config:4, ver:8;
140 unsigned int ver:8, config:4, sz:4, line_len:4, pad:12;
144 p_ic = &cpuinfo_arc700[cpu].icache;
145 READ_BCR(ARC_REG_IC_BCR, ibcr);
147 BUG_ON(ibcr.config != 3);
148 p_ic->assoc = 2; /* Fixed to 2w set assoc */
149 p_ic->line_len = 8 << ibcr.line_len;
150 p_ic->sz = 0x200 << ibcr.sz;
151 p_ic->ver = ibcr.ver;
153 p_dc = &cpuinfo_arc700[cpu].dcache;
154 READ_BCR(ARC_REG_DC_BCR, dbcr);
156 BUG_ON(dbcr.config != 2);
157 p_dc->assoc = 4; /* Fixed to 4w set assoc */
158 p_dc->line_len = 16 << dbcr.line_len;
159 p_dc->sz = 0x200 << dbcr.sz;
160 p_dc->ver = dbcr.ver;
164 * 1. Validate the Cache Geomtery (compile time config matches hardware)
165 * 2. If I-cache suffers from aliasing, setup work arounds (difft flush rtn)
166 * (aliasing D-cache configurations are not supported YET)
167 * 3. Enable the Caches, setup default flush mode for D-Cache
168 * 3. Calculate the SHMLBA used by user space
170 void arc_cache_init(void)
172 unsigned int cpu = smp_processor_id();
173 struct cpuinfo_arc_cache *ic = &cpuinfo_arc700[cpu].icache;
174 struct cpuinfo_arc_cache *dc = &cpuinfo_arc700[cpu].dcache;
175 unsigned int dcache_does_alias, temp;
178 printk(arc_cache_mumbojumbo(0, str, sizeof(str)));
183 #ifdef CONFIG_ARC_HAS_ICACHE
184 /* 1. Confirm some of I-cache params which Linux assumes */
185 if (ic->line_len != ARC_ICACHE_LINE_LEN)
186 panic("Cache H/W doesn't match kernel Config");
188 if (ic->ver != CONFIG_ARC_MMU_VER)
189 panic("Cache ver doesn't match MMU ver\n");
192 /* Enable/disable I-Cache */
193 temp = read_aux_reg(ARC_REG_IC_CTRL);
195 #ifdef CONFIG_ARC_HAS_ICACHE
196 temp &= ~IC_CTRL_CACHE_DISABLE;
198 temp |= IC_CTRL_CACHE_DISABLE;
201 write_aux_reg(ARC_REG_IC_CTRL, temp);
207 #ifdef CONFIG_ARC_HAS_DCACHE
208 if (dc->line_len != ARC_DCACHE_LINE_LEN)
209 panic("Cache H/W doesn't match kernel Config");
211 /* check for D-Cache aliasing */
212 dcache_does_alias = (dc->sz / dc->assoc) > PAGE_SIZE;
214 if (dcache_does_alias && !cache_is_vipt_aliasing())
215 panic("Enable CONFIG_ARC_CACHE_VIPT_ALIASING\n");
216 else if (!dcache_does_alias && cache_is_vipt_aliasing())
217 panic("Don't need CONFIG_ARC_CACHE_VIPT_ALIASING\n");
220 /* Set the default Invalidate Mode to "simpy discard dirty lines"
221 * as this is more frequent then flush before invalidate
222 * Ofcourse we toggle this default behviour when desired
224 temp = read_aux_reg(ARC_REG_DC_CTRL);
225 temp &= ~DC_CTRL_INV_MODE_FLUSH;
227 #ifdef CONFIG_ARC_HAS_DCACHE
228 /* Enable D-Cache: Clear Bit 0 */
229 write_aux_reg(ARC_REG_DC_CTRL, temp & ~IC_CTRL_CACHE_DISABLE);
232 write_aux_reg(ARC_REG_DC_FLSH, 0x1);
233 /* Disable D cache */
234 write_aux_reg(ARC_REG_DC_CTRL, temp | IC_CTRL_CACHE_DISABLE);
242 #define OP_FLUSH_N_INV 0x3
244 #ifdef CONFIG_ARC_HAS_DCACHE
246 /***************************************************************
247 * Machine specific helpers for Entire D-Cache or Per Line ops
250 static inline void wait_for_flush(void)
252 while (read_aux_reg(ARC_REG_DC_CTRL) & DC_CTRL_FLUSH_STATUS)
257 * Operation on Entire D-Cache
258 * @cacheop = {OP_INV, OP_FLUSH, OP_FLUSH_N_INV}
259 * Note that constant propagation ensures all the checks are gone
262 static inline void __dc_entire_op(const int cacheop)
264 unsigned int tmp = tmp;
267 if (cacheop == OP_FLUSH_N_INV) {
268 /* Dcache provides 2 cmd: FLUSH or INV
269 * INV inturn has sub-modes: DISCARD or FLUSH-BEFORE
270 * flush-n-inv is achieved by INV cmd but with IM=1
271 * Default INV sub-mode is DISCARD, which needs to be toggled
273 tmp = read_aux_reg(ARC_REG_DC_CTRL);
274 write_aux_reg(ARC_REG_DC_CTRL, tmp | DC_CTRL_INV_MODE_FLUSH);
277 if (cacheop & OP_INV) /* Inv or flush-n-inv use same cmd reg */
278 aux = ARC_REG_DC_IVDC;
280 aux = ARC_REG_DC_FLSH;
282 write_aux_reg(aux, 0x1);
284 if (cacheop & OP_FLUSH) /* flush / flush-n-inv both wait */
287 /* Switch back the DISCARD ONLY Invalidate mode */
288 if (cacheop == OP_FLUSH_N_INV)
289 write_aux_reg(ARC_REG_DC_CTRL, tmp & ~DC_CTRL_INV_MODE_FLUSH);
293 * Per Line Operation on D-Cache
294 * Doesn't deal with type-of-op/IRQ-disabling/waiting-for-flush-to-complete
295 * It's sole purpose is to help gcc generate ZOL
296 * (aliasing VIPT dcache flushing needs both vaddr and paddr)
298 static inline void __dc_line_loop(unsigned long paddr, unsigned long vaddr,
299 unsigned long sz, const int cacheop)
301 /* which MMU cmd: INV (discard or wback-n-discard) OR FLUSH (wback) */
302 const int aux = cacheop & OP_INV ? ARC_REG_DC_IVDL : ARC_REG_DC_FLDL;
305 /* Ensure we properly floor/ceil the non-line aligned/sized requests
306 * and have @paddr - aligned to cache line and integral @num_lines.
307 * This however can be avoided for page sized since:
308 * -@paddr will be cache-line aligned already (being page aligned)
309 * -@sz will be integral multiple of line size (being page sized).
311 if (!(__builtin_constant_p(sz) && sz == PAGE_SIZE)) {
312 sz += paddr & ~DCACHE_LINE_MASK;
313 paddr &= DCACHE_LINE_MASK;
314 vaddr &= DCACHE_LINE_MASK;
317 num_lines = DIV_ROUND_UP(sz, ARC_DCACHE_LINE_LEN);
319 #if (CONFIG_ARC_MMU_VER <= 2)
320 paddr |= (vaddr >> PAGE_SHIFT) & 0x1F;
323 while (num_lines-- > 0) {
324 #if (CONFIG_ARC_MMU_VER > 2)
326 * Just as for I$, in MMU v3, D$ ops also require
327 * "tag" bits in DC_PTAG, "index" bits in FLDL,IVDL ops
329 write_aux_reg(ARC_REG_DC_PTAG, paddr);
331 write_aux_reg(aux, vaddr);
332 vaddr += ARC_DCACHE_LINE_LEN;
334 /* paddr contains stuffed vaddrs bits */
335 write_aux_reg(aux, paddr);
337 paddr += ARC_DCACHE_LINE_LEN;
341 /* For kernel mappings cache operation: index is same as paddr */
342 #define __dc_line_op_k(p, sz, op) __dc_line_op(p, p, sz, op)
345 * D-Cache : Per Line INV (discard or wback+discard) or FLUSH (wback)
347 static inline void __dc_line_op(unsigned long paddr, unsigned long vaddr,
348 unsigned long sz, const int cacheop)
350 unsigned long flags, tmp = tmp;
352 local_irq_save(flags);
354 if (cacheop == OP_FLUSH_N_INV) {
356 * Dcache provides 2 cmd: FLUSH or INV
357 * INV inturn has sub-modes: DISCARD or FLUSH-BEFORE
358 * flush-n-inv is achieved by INV cmd but with IM=1
359 * Default INV sub-mode is DISCARD, which needs to be toggled
361 tmp = read_aux_reg(ARC_REG_DC_CTRL);
362 write_aux_reg(ARC_REG_DC_CTRL, tmp | DC_CTRL_INV_MODE_FLUSH);
365 __dc_line_loop(paddr, vaddr, sz, cacheop);
367 if (cacheop & OP_FLUSH) /* flush / flush-n-inv both wait */
370 /* Switch back the DISCARD ONLY Invalidate mode */
371 if (cacheop == OP_FLUSH_N_INV)
372 write_aux_reg(ARC_REG_DC_CTRL, tmp & ~DC_CTRL_INV_MODE_FLUSH);
374 local_irq_restore(flags);
379 #define __dc_entire_op(cacheop)
380 #define __dc_line_op(paddr, vaddr, sz, cacheop)
381 #define __dc_line_op_k(paddr, sz, cacheop)
383 #endif /* CONFIG_ARC_HAS_DCACHE */
386 #ifdef CONFIG_ARC_HAS_ICACHE
389 * I-Cache Aliasing in ARC700 VIPT caches
391 * ARC VIPT I-cache uses vaddr to index into cache and paddr to match the tag.
392 * The orig Cache Management Module "CDU" only required paddr to invalidate a
393 * certain line since it sufficed as index in Non-Aliasing VIPT cache-geometry.
394 * Infact for distinct V1,V2,P: all of {V1-P},{V2-P},{P-P} would end up fetching
395 * the exact same line.
397 * However for larger Caches (way-size > page-size) - i.e. in Aliasing config,
398 * paddr alone could not be used to correctly index the cache.
401 * MMU v1/v2 (Fixed Page Size 8k)
403 * The solution was to provide CDU with these additonal vaddr bits. These
404 * would be bits [x:13], x would depend on cache-geometry, 13 comes from
405 * standard page size of 8k.
406 * H/w folks chose [17:13] to be a future safe range, and moreso these 5 bits
407 * of vaddr could easily be "stuffed" in the paddr as bits [4:0] since the
408 * orig 5 bits of paddr were anyways ignored by CDU line ops, as they
409 * represent the offset within cache-line. The adv of using this "clumsy"
410 * interface for additional info was no new reg was needed in CDU programming
413 * 17:13 represented the max num of bits passable, actual bits needed were
414 * fewer, based on the num-of-aliases possible.
415 * -for 2 alias possibility, only bit 13 needed (32K cache)
416 * -for 4 alias possibility, bits 14:13 needed (64K cache)
421 * This ver of MMU supports variable page sizes (1k-16k): although Linux will
422 * only support 8k (default), 16k and 4k.
423 * However from hardware perspective, smaller page sizes aggrevate aliasing
424 * meaning more vaddr bits needed to disambiguate the cache-line-op ;
425 * the existing scheme of piggybacking won't work for certain configurations.
426 * Two new registers IC_PTAG and DC_PTAG inttoduced.
427 * "tag" bits are provided in PTAG, index bits in existing IVIL/IVDL/FLDL regs
430 /***********************************************************
431 * Machine specific helper for per line I-Cache invalidate.
433 static void __ic_line_inv_vaddr(unsigned long paddr, unsigned long vaddr,
440 * Ensure we properly floor/ceil the non-line aligned/sized requests:
441 * However page sized flushes can be compile time optimised.
442 * -@paddr will be cache-line aligned already (being page aligned)
443 * -@sz will be integral multiple of line size (being page sized).
445 if (!(__builtin_constant_p(sz) && sz == PAGE_SIZE)) {
446 sz += paddr & ~ICACHE_LINE_MASK;
447 paddr &= ICACHE_LINE_MASK;
448 vaddr &= ICACHE_LINE_MASK;
451 num_lines = DIV_ROUND_UP(sz, ARC_ICACHE_LINE_LEN);
453 #if (CONFIG_ARC_MMU_VER <= 2)
454 /* bits 17:13 of vaddr go as bits 4:0 of paddr */
455 paddr |= (vaddr >> PAGE_SHIFT) & 0x1F;
458 local_irq_save(flags);
459 while (num_lines-- > 0) {
460 #if (CONFIG_ARC_MMU_VER > 2)
461 /* tag comes from phy addr */
462 write_aux_reg(ARC_REG_IC_PTAG, paddr);
464 /* index bits come from vaddr */
465 write_aux_reg(ARC_REG_IC_IVIL, vaddr);
466 vaddr += ARC_ICACHE_LINE_LEN;
468 /* paddr contains stuffed vaddrs bits */
469 write_aux_reg(ARC_REG_IC_IVIL, paddr);
471 paddr += ARC_ICACHE_LINE_LEN;
473 local_irq_restore(flags);
476 static inline void __ic_entire_inv(void)
478 write_aux_reg(ARC_REG_IC_IVIC, 1);
479 read_aux_reg(ARC_REG_IC_CTRL); /* blocks */
484 #define __ic_entire_inv()
485 #define __ic_line_inv_vaddr(pstart, vstart, sz)
487 #endif /* CONFIG_ARC_HAS_ICACHE */
490 /***********************************************************
495 * Handle cache congruency of kernel and userspace mappings of page when kernel
496 * writes-to/reads-from
498 * The idea is to defer flushing of kernel mapping after a WRITE, possible if:
499 * -dcache is NOT aliasing, hence any U/K-mappings of page are congruent
500 * -U-mapping doesn't exist yet for page (finalised in update_mmu_cache)
501 * -In SMP, if hardware caches are coherent
503 * There's a corollary case, where kernel READs from a userspace mapped page.
504 * If the U-mapping is not congruent to to K-mapping, former needs flushing.
506 void flush_dcache_page(struct page *page)
508 struct address_space *mapping;
510 if (!cache_is_vipt_aliasing()) {
511 clear_bit(PG_dc_clean, &page->flags);
515 /* don't handle anon pages here */
516 mapping = page_mapping(page);
521 * pagecache page, file not yet mapped to userspace
522 * Make a note that K-mapping is dirty
524 if (!mapping_mapped(mapping)) {
525 clear_bit(PG_dc_clean, &page->flags);
526 } else if (page_mapped(page)) {
528 /* kernel reading from page with U-mapping */
529 void *paddr = page_address(page);
530 unsigned long vaddr = page->index << PAGE_CACHE_SHIFT;
532 if (addr_not_cache_congruent(paddr, vaddr))
533 __flush_dcache_page(paddr, vaddr);
536 EXPORT_SYMBOL(flush_dcache_page);
539 void dma_cache_wback_inv(unsigned long start, unsigned long sz)
541 __dc_line_op_k(start, sz, OP_FLUSH_N_INV);
543 EXPORT_SYMBOL(dma_cache_wback_inv);
545 void dma_cache_inv(unsigned long start, unsigned long sz)
547 __dc_line_op_k(start, sz, OP_INV);
549 EXPORT_SYMBOL(dma_cache_inv);
551 void dma_cache_wback(unsigned long start, unsigned long sz)
553 __dc_line_op_k(start, sz, OP_FLUSH);
555 EXPORT_SYMBOL(dma_cache_wback);
558 * This is API for making I/D Caches consistent when modifying
559 * kernel code (loadable modules, kprobes, kgdb...)
560 * This is called on insmod, with kernel virtual address for CODE of
561 * the module. ARC cache maintenance ops require PHY address thus we
562 * need to convert vmalloc addr to PHY addr
564 void flush_icache_range(unsigned long kstart, unsigned long kend)
566 unsigned int tot_sz, off, sz;
567 unsigned long phy, pfn;
569 /* printk("Kernel Cache Cohenercy: %lx to %lx\n",kstart, kend); */
571 /* This is not the right API for user virtual address */
572 if (kstart < TASK_SIZE) {
573 BUG_ON("Flush icache range for user virtual addr space");
577 /* Shortcut for bigger flush ranges.
578 * Here we don't care if this was kernel virtual or phy addr
580 tot_sz = kend - kstart;
581 if (tot_sz > PAGE_SIZE) {
586 /* Case: Kernel Phy addr (0x8000_0000 onwards) */
587 if (likely(kstart > PAGE_OFFSET)) {
589 * The 2nd arg despite being paddr will be used to index icache
590 * This is OK since no alternate virtual mappings will exist
591 * given the callers for this case: kprobe/kgdb in built-in
594 __sync_icache_dcache(kstart, kstart, kend - kstart);
599 * Case: Kernel Vaddr (0x7000_0000 to 0x7fff_ffff)
600 * (1) ARC Cache Maintenance ops only take Phy addr, hence special
601 * handling of kernel vaddr.
603 * (2) Despite @tot_sz being < PAGE_SIZE (bigger cases handled already),
604 * it still needs to handle a 2 page scenario, where the range
605 * straddles across 2 virtual pages and hence need for loop
608 off = kstart % PAGE_SIZE;
609 pfn = vmalloc_to_pfn((void *)kstart);
610 phy = (pfn << PAGE_SHIFT) + off;
611 sz = min_t(unsigned int, tot_sz, PAGE_SIZE - off);
612 __sync_icache_dcache(phy, kstart, sz);
619 * General purpose helper to make I and D cache lines consistent.
620 * @paddr is phy addr of region
621 * @vaddr is typically user vaddr (breakpoint) or kernel vaddr (vmalloc)
622 * However in one instance, when called by kprobe (for a breakpt in
623 * builtin kernel code) @vaddr will be paddr only, meaning CDU operation will
624 * use a paddr to index the cache (despite VIPT). This is fine since since a
625 * builtin kernel page will not have any virtual mappings.
626 * kprobe on loadable module will be kernel vaddr.
628 void __sync_icache_dcache(unsigned long paddr, unsigned long vaddr, int len)
632 local_irq_save(flags);
633 __ic_line_inv_vaddr(paddr, vaddr, len);
634 __dc_line_op(paddr, vaddr, len, OP_FLUSH_N_INV);
635 local_irq_restore(flags);
638 /* wrapper to compile time eliminate alignment checks in flush loop */
639 void __inv_icache_page(unsigned long paddr, unsigned long vaddr)
641 __ic_line_inv_vaddr(paddr, vaddr, PAGE_SIZE);
645 * wrapper to clearout kernel or userspace mappings of a page
646 * For kernel mappings @vaddr == @paddr
648 void ___flush_dcache_page(unsigned long paddr, unsigned long vaddr)
650 __dc_line_op(paddr, vaddr & PAGE_MASK, PAGE_SIZE, OP_FLUSH_N_INV);
653 noinline void flush_cache_all(void)
657 local_irq_save(flags);
660 __dc_entire_op(OP_FLUSH_N_INV);
662 local_irq_restore(flags);
666 #ifdef CONFIG_ARC_CACHE_VIPT_ALIASING
668 void flush_cache_mm(struct mm_struct *mm)
673 void flush_cache_page(struct vm_area_struct *vma, unsigned long u_vaddr,
676 unsigned int paddr = pfn << PAGE_SHIFT;
678 u_vaddr &= PAGE_MASK;
680 ___flush_dcache_page(paddr, u_vaddr);
682 if (vma->vm_flags & VM_EXEC)
683 __inv_icache_page(paddr, u_vaddr);
686 void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
692 void flush_anon_page(struct vm_area_struct *vma, struct page *page,
693 unsigned long u_vaddr)
695 /* TBD: do we really need to clear the kernel mapping */
696 __flush_dcache_page(page_address(page), u_vaddr);
697 __flush_dcache_page(page_address(page), page_address(page));
703 void copy_user_highpage(struct page *to, struct page *from,
704 unsigned long u_vaddr, struct vm_area_struct *vma)
706 void *kfrom = page_address(from);
707 void *kto = page_address(to);
708 int clean_src_k_mappings = 0;
711 * If SRC page was already mapped in userspace AND it's U-mapping is
712 * not congruent with K-mapping, sync former to physical page so that
713 * K-mapping in memcpy below, sees the right data
715 * Note that while @u_vaddr refers to DST page's userspace vaddr, it is
716 * equally valid for SRC page as well
718 if (page_mapped(from) && addr_not_cache_congruent(kfrom, u_vaddr)) {
719 __flush_dcache_page(kfrom, u_vaddr);
720 clean_src_k_mappings = 1;
723 copy_page(kto, kfrom);
726 * Mark DST page K-mapping as dirty for a later finalization by
727 * update_mmu_cache(). Although the finalization could have been done
728 * here as well (given that both vaddr/paddr are available).
729 * But update_mmu_cache() already has code to do that for other
730 * non copied user pages (e.g. read faults which wire in pagecache page
733 clear_bit(PG_dc_clean, &to->flags);
736 * if SRC was already usermapped and non-congruent to kernel mapping
737 * sync the kernel mapping back to physical page
739 if (clean_src_k_mappings) {
740 __flush_dcache_page(kfrom, kfrom);
741 set_bit(PG_dc_clean, &from->flags);
743 clear_bit(PG_dc_clean, &from->flags);
747 void clear_user_page(void *to, unsigned long u_vaddr, struct page *page)
750 clear_bit(PG_dc_clean, &page->flags);
754 /**********************************************************************
755 * Explicit Cache flush request from user space via syscall
756 * Needed for JITs which generate code on the fly
758 SYSCALL_DEFINE3(cacheflush, uint32_t, start, uint32_t, sz, uint32_t, flags)
760 /* TBD: optimize this */