xref: /openbmc/qemu/util/cacheflush.c (revision e9e51b71)
1 /*
2  * Flush the host cpu caches.
3  *
4  * This work is licensed under the terms of the GNU GPL, version 2 or later.
5  * See the COPYING file in the top-level directory.
6  */
7 
8 #include "qemu/osdep.h"
9 #include "qemu/cacheflush.h"
10 #include "qemu/bitops.h"
11 
12 
13 #if defined(__i386__) || defined(__x86_64__) || defined(__s390__)
14 
15 /* Caches are coherent and do not require flushing; symbol inline. */
16 
17 #elif defined(__aarch64__)
18 
19 #ifdef CONFIG_DARWIN
20 /* Apple does not expose CTR_EL0, so we must use system interfaces. */
21 extern void sys_icache_invalidate(void *start, size_t len);
22 extern void sys_dcache_flush(void *start, size_t len);
23 void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t len)
24 {
25     sys_dcache_flush((void *)rw, len);
26     sys_icache_invalidate((void *)rx, len);
27 }
28 #else
29 
30 /*
31  * TODO: unify this with cacheinfo.c.
32  * We want to save the whole contents of CTR_EL0, so that we
33  * have more than the linesize, but also IDC and DIC.
34  */
35 static uint64_t save_ctr_el0;
36 static void __attribute__((constructor)) init_ctr_el0(void)
37 {
38     asm volatile("mrs\t%0, ctr_el0" : "=r"(save_ctr_el0));
39 }
40 
41 /*
42  * This is a copy of gcc's __aarch64_sync_cache_range, modified
43  * to fit this three-operand interface.
44  */
45 void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t len)
46 {
47     const unsigned CTR_IDC = 1u << 28;
48     const unsigned CTR_DIC = 1u << 29;
49     const uint64_t ctr_el0 = save_ctr_el0;
50     const uintptr_t icache_lsize = 4 << extract64(ctr_el0, 0, 4);
51     const uintptr_t dcache_lsize = 4 << extract64(ctr_el0, 16, 4);
52     uintptr_t p;
53 
54     /*
55      * If CTR_EL0.IDC is enabled, Data cache clean to the Point of Unification
56      * is not required for instruction to data coherence.
57      */
58     if (!(ctr_el0 & CTR_IDC)) {
59         /*
60          * Loop over the address range, clearing one cache line at once.
61          * Data cache must be flushed to unification first to make sure
62          * the instruction cache fetches the updated data.
63          */
64         for (p = rw & -dcache_lsize; p < rw + len; p += dcache_lsize) {
65             asm volatile("dc\tcvau, %0" : : "r" (p) : "memory");
66         }
67         asm volatile("dsb\tish" : : : "memory");
68     }
69 
70     /*
71      * If CTR_EL0.DIC is enabled, Instruction cache cleaning to the Point
72      * of Unification is not required for instruction to data coherence.
73      */
74     if (!(ctr_el0 & CTR_DIC)) {
75         for (p = rx & -icache_lsize; p < rx + len; p += icache_lsize) {
76             asm volatile("ic\tivau, %0" : : "r"(p) : "memory");
77         }
78         asm volatile ("dsb\tish" : : : "memory");
79     }
80 
81     asm volatile("isb" : : : "memory");
82 }
83 #endif /* CONFIG_DARWIN */
84 
85 #elif defined(__mips__)
86 
87 #ifdef __OpenBSD__
88 #include <machine/sysarch.h>
89 #else
90 #include <sys/cachectl.h>
91 #endif
92 
93 void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t len)
94 {
95     if (rx != rw) {
96         cacheflush((void *)rw, len, DCACHE);
97     }
98     cacheflush((void *)rx, len, ICACHE);
99 }
100 
101 #elif defined(__powerpc__)
102 
103 void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t len)
104 {
105     uintptr_t p, b, e;
106     size_t dsize = qemu_dcache_linesize;
107     size_t isize = qemu_icache_linesize;
108 
109     b = rw & ~(dsize - 1);
110     e = (rw + len + dsize - 1) & ~(dsize - 1);
111     for (p = b; p < e; p += dsize) {
112         asm volatile ("dcbst 0,%0" : : "r"(p) : "memory");
113     }
114     asm volatile ("sync" : : : "memory");
115 
116     b = rx & ~(isize - 1);
117     e = (rx + len + isize - 1) & ~(isize - 1);
118     for (p = b; p < e; p += isize) {
119         asm volatile ("icbi 0,%0" : : "r"(p) : "memory");
120     }
121     asm volatile ("sync" : : : "memory");
122     asm volatile ("isync" : : : "memory");
123 }
124 
125 #elif defined(__sparc__)
126 
127 void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t len)
128 {
129     /* No additional data flush to the RW virtual address required. */
130     uintptr_t p, end = (rx + len + 7) & -8;
131     for (p = rx & -8; p < end; p += 8) {
132         __asm__ __volatile__("flush\t%0" : : "r" (p));
133     }
134 }
135 
136 #else
137 
138 void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t len)
139 {
140     if (rw != rx) {
141         __builtin___clear_cache((char *)rw, (char *)rw + len);
142     }
143     __builtin___clear_cache((char *)rx, (char *)rx + len);
144 }
145 
146 #endif
147