xref: /openbmc/linux/arch/openrisc/mm/cache.c (revision e3b9f1e8)
1 /*
2  * OpenRISC cache.c
3  *
4  * Linux architectural port borrowing liberally from similar works of
5  * others.  All original copyrights apply as per the original source
6  * declaration.
7  *
8  * Modifications for the OpenRISC architecture:
9  * Copyright (C) 2015 Jan Henrik Weinstock <jan.weinstock@rwth-aachen.de>
10  *
11  *      This program is free software; you can redistribute it and/or
12  *      modify it under the terms of the GNU General Public License
13  *      as published by the Free Software Foundation; either version
14  *      2 of the License, or (at your option) any later version.
15  */
16 
17 #include <asm/spr.h>
18 #include <asm/spr_defs.h>
19 #include <asm/cache.h>
20 #include <asm/cacheflush.h>
21 #include <asm/tlbflush.h>
22 
23 static void cache_loop(struct page *page, const unsigned int reg)
24 {
25 	unsigned long paddr = page_to_pfn(page) << PAGE_SHIFT;
26 	unsigned long line = paddr & ~(L1_CACHE_BYTES - 1);
27 
28 	while (line < paddr + PAGE_SIZE) {
29 		mtspr(reg, line);
30 		line += L1_CACHE_BYTES;
31 	}
32 }
33 
34 void local_dcache_page_flush(struct page *page)
35 {
36 	cache_loop(page, SPR_DCBFR);
37 }
38 EXPORT_SYMBOL(local_dcache_page_flush);
39 
40 void local_icache_page_inv(struct page *page)
41 {
42 	cache_loop(page, SPR_ICBIR);
43 }
44 EXPORT_SYMBOL(local_icache_page_inv);
45 
46 void update_cache(struct vm_area_struct *vma, unsigned long address,
47 	pte_t *pte)
48 {
49 	unsigned long pfn = pte_val(*pte) >> PAGE_SHIFT;
50 	struct page *page = pfn_to_page(pfn);
51 	int dirty = !test_and_set_bit(PG_dc_clean, &page->flags);
52 
53 	/*
54 	 * Since icaches do not snoop for updated data on OpenRISC, we
55 	 * must write back and invalidate any dirty pages manually. We
56 	 * can skip data pages, since they will not end up in icaches.
57 	 */
58 	if ((vma->vm_flags & VM_EXEC) && dirty)
59 		sync_icache_dcache(page);
60 }
61 
62