xref: /openbmc/linux/arch/arm64/include/asm/cache.h (revision 2169e6da)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (C) 2012 ARM Ltd.
4  */
5 #ifndef __ASM_CACHE_H
6 #define __ASM_CACHE_H
7 
8 #include <asm/cputype.h>
9 
10 #define CTR_L1IP_SHIFT		14
11 #define CTR_L1IP_MASK		3
12 #define CTR_DMINLINE_SHIFT	16
13 #define CTR_IMINLINE_SHIFT	0
14 #define CTR_ERG_SHIFT		20
15 #define CTR_CWG_SHIFT		24
16 #define CTR_CWG_MASK		15
17 #define CTR_IDC_SHIFT		28
18 #define CTR_DIC_SHIFT		29
19 
20 #define CTR_CACHE_MINLINE_MASK	\
21 	(0xf << CTR_DMINLINE_SHIFT | 0xf << CTR_IMINLINE_SHIFT)
22 
23 #define CTR_L1IP(ctr)		(((ctr) >> CTR_L1IP_SHIFT) & CTR_L1IP_MASK)
24 
25 #define ICACHE_POLICY_VPIPT	0
26 #define ICACHE_POLICY_VIPT	2
27 #define ICACHE_POLICY_PIPT	3
28 
29 #define L1_CACHE_SHIFT		(6)
30 #define L1_CACHE_BYTES		(1 << L1_CACHE_SHIFT)
31 
32 
33 #define CLIDR_LOUU_SHIFT	27
34 #define CLIDR_LOC_SHIFT		24
35 #define CLIDR_LOUIS_SHIFT	21
36 
37 #define CLIDR_LOUU(clidr)	(((clidr) >> CLIDR_LOUU_SHIFT) & 0x7)
38 #define CLIDR_LOC(clidr)	(((clidr) >> CLIDR_LOC_SHIFT) & 0x7)
39 #define CLIDR_LOUIS(clidr)	(((clidr) >> CLIDR_LOUIS_SHIFT) & 0x7)
40 
41 /*
42  * Memory returned by kmalloc() may be used for DMA, so we must make
43  * sure that all such allocations are cache aligned. Otherwise,
44  * unrelated code may cause parts of the buffer to be read into the
45  * cache before the transfer is done, causing old data to be seen by
46  * the CPU.
47  */
48 #define ARCH_DMA_MINALIGN	(128)
49 
50 #ifdef CONFIG_KASAN_SW_TAGS
51 #define ARCH_SLAB_MINALIGN	(1ULL << KASAN_SHADOW_SCALE_SHIFT)
52 #endif
53 
54 #ifndef __ASSEMBLY__
55 
56 #include <linux/bitops.h>
57 
58 #define ICACHEF_ALIASING	0
59 #define ICACHEF_VPIPT		1
60 extern unsigned long __icache_flags;
61 
62 /*
63  * Whilst the D-side always behaves as PIPT on AArch64, aliasing is
64  * permitted in the I-cache.
65  */
66 static inline int icache_is_aliasing(void)
67 {
68 	return test_bit(ICACHEF_ALIASING, &__icache_flags);
69 }
70 
71 static inline int icache_is_vpipt(void)
72 {
73 	return test_bit(ICACHEF_VPIPT, &__icache_flags);
74 }
75 
76 static inline u32 cache_type_cwg(void)
77 {
78 	return (read_cpuid_cachetype() >> CTR_CWG_SHIFT) & CTR_CWG_MASK;
79 }
80 
81 #define __read_mostly __attribute__((__section__(".data..read_mostly")))
82 
83 static inline int cache_line_size_of_cpu(void)
84 {
85 	u32 cwg = cache_type_cwg();
86 
87 	return cwg ? 4 << cwg : ARCH_DMA_MINALIGN;
88 }
89 
90 int cache_line_size(void);
91 
92 /*
93  * Read the effective value of CTR_EL0.
94  *
95  * According to ARM ARM for ARMv8-A (ARM DDI 0487C.a),
96  * section D10.2.33 "CTR_EL0, Cache Type Register" :
97  *
98  * CTR_EL0.IDC reports the data cache clean requirements for
99  * instruction to data coherence.
100  *
101  *  0 - dcache clean to PoU is required unless :
102  *     (CLIDR_EL1.LoC == 0) || (CLIDR_EL1.LoUIS == 0 && CLIDR_EL1.LoUU == 0)
103  *  1 - dcache clean to PoU is not required for i-to-d coherence.
104  *
105  * This routine provides the CTR_EL0 with the IDC field updated to the
106  * effective state.
107  */
108 static inline u32 __attribute_const__ read_cpuid_effective_cachetype(void)
109 {
110 	u32 ctr = read_cpuid_cachetype();
111 
112 	if (!(ctr & BIT(CTR_IDC_SHIFT))) {
113 		u64 clidr = read_sysreg(clidr_el1);
114 
115 		if (CLIDR_LOC(clidr) == 0 ||
116 		    (CLIDR_LOUIS(clidr) == 0 && CLIDR_LOUU(clidr) == 0))
117 			ctr |= BIT(CTR_IDC_SHIFT);
118 	}
119 
120 	return ctr;
121 }
122 
123 #endif	/* __ASSEMBLY__ */
124 
125 #endif
126