xref: /openbmc/qemu/util/cacheflush.c (revision e4082063)
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/cacheinfo.h"
11 #include "qemu/bitops.h"
12 
13 
14 #if defined(__i386__) || defined(__x86_64__) || defined(__s390__)
15 
16 /* Caches are coherent and do not require flushing; symbol inline. */
17 
18 #elif defined(__aarch64__)
19 
20 #ifdef CONFIG_DARWIN
21 /* Apple does not expose CTR_EL0, so we must use system interfaces. */
22 extern void sys_icache_invalidate(void *start, size_t len);
23 extern void sys_dcache_flush(void *start, size_t len);
24 void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t len)
25 {
26     sys_dcache_flush((void *)rw, len);
27     sys_icache_invalidate((void *)rx, len);
28 }
29 #else
30 
31 /*
32  * TODO: unify this with cacheinfo.c.
33  * We want to save the whole contents of CTR_EL0, so that we
34  * have more than the linesize, but also IDC and DIC.
35  */
36 static uint64_t save_ctr_el0;
37 static void __attribute__((constructor)) init_ctr_el0(void)
38 {
39     asm volatile("mrs\t%0, ctr_el0" : "=r"(save_ctr_el0));
40 }
41 
42 /*
43  * This is a copy of gcc's __aarch64_sync_cache_range, modified
44  * to fit this three-operand interface.
45  */
46 void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t len)
47 {
48     const unsigned CTR_IDC = 1u << 28;
49     const unsigned CTR_DIC = 1u << 29;
50     const uint64_t ctr_el0 = save_ctr_el0;
51     const uintptr_t icache_lsize = 4 << extract64(ctr_el0, 0, 4);
52     const uintptr_t dcache_lsize = 4 << extract64(ctr_el0, 16, 4);
53     uintptr_t p;
54 
55     /*
56      * If CTR_EL0.IDC is enabled, Data cache clean to the Point of Unification
57      * is not required for instruction to data coherence.
58      */
59     if (!(ctr_el0 & CTR_IDC)) {
60         /*
61          * Loop over the address range, clearing one cache line at once.
62          * Data cache must be flushed to unification first to make sure
63          * the instruction cache fetches the updated data.
64          */
65         for (p = rw & -dcache_lsize; p < rw + len; p += dcache_lsize) {
66             asm volatile("dc\tcvau, %0" : : "r" (p) : "memory");
67         }
68         asm volatile("dsb\tish" : : : "memory");
69     }
70 
71     /*
72      * If CTR_EL0.DIC is enabled, Instruction cache cleaning to the Point
73      * of Unification is not required for instruction to data coherence.
74      */
75     if (!(ctr_el0 & CTR_DIC)) {
76         for (p = rx & -icache_lsize; p < rx + len; p += icache_lsize) {
77             asm volatile("ic\tivau, %0" : : "r"(p) : "memory");
78         }
79         asm volatile ("dsb\tish" : : : "memory");
80     }
81 
82     asm volatile("isb" : : : "memory");
83 }
84 #endif /* CONFIG_DARWIN */
85 
86 #elif defined(__mips__)
87 
88 #ifdef __OpenBSD__
89 #include <machine/sysarch.h>
90 #else
91 #include <sys/cachectl.h>
92 #endif
93 
94 void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t len)
95 {
96     if (rx != rw) {
97         cacheflush((void *)rw, len, DCACHE);
98     }
99     cacheflush((void *)rx, len, ICACHE);
100 }
101 
102 #elif defined(__powerpc__)
103 
104 void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t len)
105 {
106     uintptr_t p, b, e;
107     size_t dsize = qemu_dcache_linesize;
108     size_t isize = qemu_icache_linesize;
109 
110     b = rw & ~(dsize - 1);
111     e = (rw + len + dsize - 1) & ~(dsize - 1);
112     for (p = b; p < e; p += dsize) {
113         asm volatile ("dcbst 0,%0" : : "r"(p) : "memory");
114     }
115     asm volatile ("sync" : : : "memory");
116 
117     b = rx & ~(isize - 1);
118     e = (rx + len + isize - 1) & ~(isize - 1);
119     for (p = b; p < e; p += isize) {
120         asm volatile ("icbi 0,%0" : : "r"(p) : "memory");
121     }
122     asm volatile ("sync" : : : "memory");
123     asm volatile ("isync" : : : "memory");
124 }
125 
126 #elif defined(__sparc__)
127 
128 void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t len)
129 {
130     /* No additional data flush to the RW virtual address required. */
131     uintptr_t p, end = (rx + len + 7) & -8;
132     for (p = rx & -8; p < end; p += 8) {
133         __asm__ __volatile__("flush\t%0" : : "r" (p));
134     }
135 }
136 
137 #else
138 
139 void flush_idcache_range(uintptr_t rx, uintptr_t rw, size_t len)
140 {
141     if (rw != rx) {
142         __builtin___clear_cache((char *)rw, (char *)rw + len);
143     }
144     __builtin___clear_cache((char *)rx, (char *)rx + len);
145 }
146 
147 #endif
148