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1 /*
2  * Copyright (C) 2012 ARM Ltd.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public License
14  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
15  */
16 #ifndef __ASM_CACHE_H
17 #define __ASM_CACHE_H
18 
19 #include <asm/cputype.h>
20 
21 #define CTR_L1IP_SHIFT		14
22 #define CTR_L1IP_MASK		3
23 #define CTR_DMINLINE_SHIFT	16
24 #define CTR_IMINLINE_SHIFT	0
25 #define CTR_CWG_SHIFT		24
26 #define CTR_CWG_MASK		15
27 
28 #define CTR_CACHE_MINLINE_MASK	\
29 	(0xf << CTR_DMINLINE_SHIFT | 0xf << CTR_IMINLINE_SHIFT)
30 
31 #define CTR_L1IP(ctr)		(((ctr) >> CTR_L1IP_SHIFT) & CTR_L1IP_MASK)
32 
33 #define ICACHE_POLICY_VPIPT	0
34 #define ICACHE_POLICY_VIPT	2
35 #define ICACHE_POLICY_PIPT	3
36 
37 #define L1_CACHE_SHIFT		7
38 #define L1_CACHE_BYTES		(1 << L1_CACHE_SHIFT)
39 
40 /*
41  * Memory returned by kmalloc() may be used for DMA, so we must make
42  * sure that all such allocations are cache aligned. Otherwise,
43  * unrelated code may cause parts of the buffer to be read into the
44  * cache before the transfer is done, causing old data to be seen by
45  * the CPU.
46  */
47 #define ARCH_DMA_MINALIGN	L1_CACHE_BYTES
48 
49 #ifndef __ASSEMBLY__
50 
51 #include <linux/bitops.h>
52 
53 #define ICACHEF_ALIASING	0
54 #define ICACHEF_VPIPT		1
55 extern unsigned long __icache_flags;
56 
57 /*
58  * Whilst the D-side always behaves as PIPT on AArch64, aliasing is
59  * permitted in the I-cache.
60  */
icache_is_aliasing(void)61 static inline int icache_is_aliasing(void)
62 {
63 	return test_bit(ICACHEF_ALIASING, &__icache_flags);
64 }
65 
icache_is_vpipt(void)66 static inline int icache_is_vpipt(void)
67 {
68 	return test_bit(ICACHEF_VPIPT, &__icache_flags);
69 }
70 
cache_type_cwg(void)71 static inline u32 cache_type_cwg(void)
72 {
73 	return (read_cpuid_cachetype() >> CTR_CWG_SHIFT) & CTR_CWG_MASK;
74 }
75 
76 #define __read_mostly __attribute__((__section__(".data..read_mostly")))
77 
cache_line_size(void)78 static inline int cache_line_size(void)
79 {
80 	u32 cwg = cache_type_cwg();
81 	return cwg ? 4 << cwg : L1_CACHE_BYTES;
82 }
83 
84 #endif	/* __ASSEMBLY__ */
85 
86 #endif
87