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_ERG_SHIFT		20
26 #define CTR_CWG_SHIFT		24
27 #define CTR_CWG_MASK		15
28 #define CTR_IDC_SHIFT		28
29 #define CTR_DIC_SHIFT		29
30 
31 #define CTR_CACHE_MINLINE_MASK	\
32 	(0xf << CTR_DMINLINE_SHIFT | 0xf << CTR_IMINLINE_SHIFT)
33 
34 #define CTR_L1IP(ctr)		(((ctr) >> CTR_L1IP_SHIFT) & CTR_L1IP_MASK)
35 
36 #define ICACHE_POLICY_VPIPT	0
37 #define ICACHE_POLICY_VIPT	2
38 #define ICACHE_POLICY_PIPT	3
39 
40 #define L1_CACHE_SHIFT		(6)
41 #define L1_CACHE_BYTES		(1 << L1_CACHE_SHIFT)
42 
43 /*
44  * Memory returned by kmalloc() may be used for DMA, so we must make
45  * sure that all such allocations are cache aligned. Otherwise,
46  * unrelated code may cause parts of the buffer to be read into the
47  * cache before the transfer is done, causing old data to be seen by
48  * the CPU.
49  */
50 #define ARCH_DMA_MINALIGN	(128)
51 
52 #ifndef __ASSEMBLY__
53 
54 #include <linux/bitops.h>
55 
56 #define ICACHEF_ALIASING	0
57 #define ICACHEF_VPIPT		1
58 extern unsigned long __icache_flags;
59 
60 /*
61  * Whilst the D-side always behaves as PIPT on AArch64, aliasing is
62  * permitted in the I-cache.
63  */
icache_is_aliasing(void)64 static inline int icache_is_aliasing(void)
65 {
66 	return test_bit(ICACHEF_ALIASING, &__icache_flags);
67 }
68 
icache_is_vpipt(void)69 static inline int icache_is_vpipt(void)
70 {
71 	return test_bit(ICACHEF_VPIPT, &__icache_flags);
72 }
73 
cache_type_cwg(void)74 static inline u32 cache_type_cwg(void)
75 {
76 	return (read_cpuid_cachetype() >> CTR_CWG_SHIFT) & CTR_CWG_MASK;
77 }
78 
79 #define __read_mostly __attribute__((__section__(".data..read_mostly")))
80 
cache_line_size(void)81 static inline int cache_line_size(void)
82 {
83 	u32 cwg = cache_type_cwg();
84 	return cwg ? 4 << cwg : ARCH_DMA_MINALIGN;
85 }
86 
87 #endif	/* __ASSEMBLY__ */
88 
89 #endif
90