xref: /openbmc/linux/arch/openrisc/mm/cache.c (revision 9aa2cba7)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * OpenRISC cache.c
4  *
5  * Linux architectural port borrowing liberally from similar works of
6  * others.  All original copyrights apply as per the original source
7  * declaration.
8  *
9  * Modifications for the OpenRISC architecture:
10  * Copyright (C) 2015 Jan Henrik Weinstock <jan.weinstock@rwth-aachen.de>
11  */
12 
13 #include <asm/spr.h>
14 #include <asm/spr_defs.h>
15 #include <asm/cache.h>
16 #include <asm/cacheflush.h>
17 #include <asm/tlbflush.h>
18 
19 static __always_inline void cache_loop(struct page *page, const unsigned int reg)
20 {
21 	unsigned long paddr = page_to_pfn(page) << PAGE_SHIFT;
22 	unsigned long line = paddr & ~(L1_CACHE_BYTES - 1);
23 
24 	while (line < paddr + PAGE_SIZE) {
25 		mtspr(reg, line);
26 		line += L1_CACHE_BYTES;
27 	}
28 }
29 
30 void local_dcache_page_flush(struct page *page)
31 {
32 	cache_loop(page, SPR_DCBFR);
33 }
34 EXPORT_SYMBOL(local_dcache_page_flush);
35 
36 void local_icache_page_inv(struct page *page)
37 {
38 	cache_loop(page, SPR_ICBIR);
39 }
40 EXPORT_SYMBOL(local_icache_page_inv);
41 
42 void update_cache(struct vm_area_struct *vma, unsigned long address,
43 	pte_t *pte)
44 {
45 	unsigned long pfn = pte_val(*pte) >> PAGE_SHIFT;
46 	struct folio *folio = page_folio(pfn_to_page(pfn));
47 	int dirty = !test_and_set_bit(PG_dc_clean, &folio->flags);
48 
49 	/*
50 	 * Since icaches do not snoop for updated data on OpenRISC, we
51 	 * must write back and invalidate any dirty pages manually. We
52 	 * can skip data pages, since they will not end up in icaches.
53 	 */
54 	if ((vma->vm_flags & VM_EXEC) && dirty) {
55 		unsigned int nr = folio_nr_pages(folio);
56 
57 		while (nr--)
58 			sync_icache_dcache(folio_page(folio, nr));
59 	}
60 }
61 
62