cache.c

 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/cpuinfo.h>
18#include <asm/tlbflush.h>
19
20/*
21 * Check if the cache component exists.
22 */
23bool cpu_cache_is_present(const unsigned int cache_type)
24{
25	unsigned long upr = mfspr(SPR_UPR);
26	unsigned long mask = SPR_UPR_UP | cache_type;
27
28	return !((upr & mask) ^ mask);
29}
30
31static __always_inline void cache_loop(unsigned long paddr, unsigned long end,
32				       const unsigned short reg, const unsigned int cache_type)
33{
34	if (!cpu_cache_is_present(cache_type))
35		return;
36
37	while (paddr < end) {
38		mtspr(reg, paddr);
39		paddr += L1_CACHE_BYTES;
40	}
41}
42
43static __always_inline void cache_loop_page(struct page *page, const unsigned short reg,
44					    const unsigned int cache_type)
45{
46	unsigned long paddr = page_to_pfn(page) << PAGE_SHIFT;
47	unsigned long end = paddr + PAGE_SIZE;
48
49	paddr &= ~(L1_CACHE_BYTES - 1);
50
51	cache_loop(paddr, end, reg, cache_type);
52}
53
54void local_dcache_page_flush(struct page *page)
55{
56	cache_loop_page(page, SPR_DCBFR, SPR_UPR_DCP);
57}
58EXPORT_SYMBOL(local_dcache_page_flush);
59
60void local_icache_page_inv(struct page *page)
61{
62	cache_loop_page(page, SPR_ICBIR, SPR_UPR_ICP);
63}
64EXPORT_SYMBOL(local_icache_page_inv);
65
66void local_dcache_range_flush(unsigned long start, unsigned long end)
67{
68	cache_loop(start, end, SPR_DCBFR, SPR_UPR_DCP);
69}
70
71void local_dcache_range_inv(unsigned long start, unsigned long end)
72{
73	cache_loop(start, end, SPR_DCBIR, SPR_UPR_DCP);
74}
75
76void local_icache_range_inv(unsigned long start, unsigned long end)
77{
78	cache_loop(start, end, SPR_ICBIR, SPR_UPR_ICP);
79}
80
81void update_cache(struct vm_area_struct *vma, unsigned long address,
82	pte_t *pte)
83{
84	unsigned long pfn = pte_val(*pte) >> PAGE_SHIFT;
85	struct folio *folio = page_folio(pfn_to_page(pfn));
86	int dirty = !test_and_set_bit(PG_dc_clean, &folio->flags.f);
87
88	/*
89	 * Since icaches do not snoop for updated data on OpenRISC, we
90	 * must write back and invalidate any dirty pages manually. We
91	 * can skip data pages, since they will not end up in icaches.
92	 */
93	if ((vma->vm_flags & VM_EXEC) && dirty) {
94		unsigned int nr = folio_nr_pages(folio);
95
96		while (nr--)
97			sync_icache_dcache(folio_page(folio, nr));
98	}
99}