xref: /openbmc/linux/arch/arm64/include/asm/cache.h (revision dc6a81c3)
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_IMINLINE_MASK	0xf
15 #define CTR_ERG_SHIFT		20
16 #define CTR_CWG_SHIFT		24
17 #define CTR_CWG_MASK		15
18 #define CTR_IDC_SHIFT		28
19 #define CTR_DIC_SHIFT		29
20 
21 #define CTR_CACHE_MINLINE_MASK	\
22 	(0xf << CTR_DMINLINE_SHIFT | CTR_IMINLINE_MASK << CTR_IMINLINE_SHIFT)
23 
24 #define CTR_L1IP(ctr)		(((ctr) >> CTR_L1IP_SHIFT) & CTR_L1IP_MASK)
25 
26 #define ICACHE_POLICY_VPIPT	0
27 #define ICACHE_POLICY_VIPT	2
28 #define ICACHE_POLICY_PIPT	3
29 
30 #define L1_CACHE_SHIFT		(6)
31 #define L1_CACHE_BYTES		(1 << L1_CACHE_SHIFT)
32 
33 
34 #define CLIDR_LOUU_SHIFT	27
35 #define CLIDR_LOC_SHIFT		24
36 #define CLIDR_LOUIS_SHIFT	21
37 
38 #define CLIDR_LOUU(clidr)	(((clidr) >> CLIDR_LOUU_SHIFT) & 0x7)
39 #define CLIDR_LOC(clidr)	(((clidr) >> CLIDR_LOC_SHIFT) & 0x7)
40 #define CLIDR_LOUIS(clidr)	(((clidr) >> CLIDR_LOUIS_SHIFT) & 0x7)
41 
42 /*
43  * Memory returned by kmalloc() may be used for DMA, so we must make
44  * sure that all such allocations are cache aligned. Otherwise,
45  * unrelated code may cause parts of the buffer to be read into the
46  * cache before the transfer is done, causing old data to be seen by
47  * the CPU.
48  */
49 #define ARCH_DMA_MINALIGN	(128)
50 
51 #ifdef CONFIG_KASAN_SW_TAGS
52 #define ARCH_SLAB_MINALIGN	(1ULL << KASAN_SHADOW_SCALE_SHIFT)
53 #endif
54 
55 #ifndef __ASSEMBLY__
56 
57 #include <linux/bitops.h>
58 
59 #define ICACHEF_ALIASING	0
60 #define ICACHEF_VPIPT		1
61 extern unsigned long __icache_flags;
62 
63 /*
64  * Whilst the D-side always behaves as PIPT on AArch64, aliasing is
65  * permitted in the I-cache.
66  */
67 static inline int icache_is_aliasing(void)
68 {
69 	return test_bit(ICACHEF_ALIASING, &__icache_flags);
70 }
71 
72 static inline int icache_is_vpipt(void)
73 {
74 	return test_bit(ICACHEF_VPIPT, &__icache_flags);
75 }
76 
77 static inline u32 cache_type_cwg(void)
78 {
79 	return (read_cpuid_cachetype() >> CTR_CWG_SHIFT) & CTR_CWG_MASK;
80 }
81 
82 #define __read_mostly __section(.data..read_mostly)
83 
84 static inline int cache_line_size_of_cpu(void)
85 {
86 	u32 cwg = cache_type_cwg();
87 
88 	return cwg ? 4 << cwg : ARCH_DMA_MINALIGN;
89 }
90 
91 int cache_line_size(void);
92 
93 /*
94  * Read the effective value of CTR_EL0.
95  *
96  * According to ARM ARM for ARMv8-A (ARM DDI 0487C.a),
97  * section D10.2.33 "CTR_EL0, Cache Type Register" :
98  *
99  * CTR_EL0.IDC reports the data cache clean requirements for
100  * instruction to data coherence.
101  *
102  *  0 - dcache clean to PoU is required unless :
103  *     (CLIDR_EL1.LoC == 0) || (CLIDR_EL1.LoUIS == 0 && CLIDR_EL1.LoUU == 0)
104  *  1 - dcache clean to PoU is not required for i-to-d coherence.
105  *
106  * This routine provides the CTR_EL0 with the IDC field updated to the
107  * effective state.
108  */
109 static inline u32 __attribute_const__ read_cpuid_effective_cachetype(void)
110 {
111 	u32 ctr = read_cpuid_cachetype();
112 
113 	if (!(ctr & BIT(CTR_IDC_SHIFT))) {
114 		u64 clidr = read_sysreg(clidr_el1);
115 
116 		if (CLIDR_LOC(clidr) == 0 ||
117 		    (CLIDR_LOUIS(clidr) == 0 && CLIDR_LOUU(clidr) == 0))
118 			ctr |= BIT(CTR_IDC_SHIFT);
119 	}
120 
121 	return ctr;
122 }
123 
124 #endif	/* __ASSEMBLY__ */
125 
126 #endif
127