1 // SPDX-License-Identifier: GPL-2.0-only 1
2 /*
3 * User address space access functions.
4 *
5 * Copyright 1997 Andi Kleen <ak@muc.de>
6 * Copyright 1997 Linus Torvalds
7 * Copyright 2002 Andi Kleen <ak@suse.de>
8 */
9 #include <linux/export.h>
10 #include <linux/uaccess.h>
11 #include <linux/highmem.h>
12 #include <linux/libnvdimm.h>
13
14 /*
15 * Zero Userspace
16 */
17
18 #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
19 /**
20 * clean_cache_range - write back a cache rang
21 * @vaddr: virtual start address
22 * @size: number of bytes to write back
23 *
24 * Write back a cache range using the CLWB (ca
25 * instruction. Note that @size is internally
26 * line size aligned.
27 */
28 static void clean_cache_range(void *addr, size
29 {
30 u16 x86_clflush_size = boot_cpu_data.x
31 unsigned long clflush_mask = x86_clflu
32 void *vend = addr + size;
33 void *p;
34
35 for (p = (void *)((unsigned long)addr
36 p < vend; p += x86_clflush_size)
37 clwb(p);
38 }
39
40 void arch_wb_cache_pmem(void *addr, size_t siz
41 {
42 clean_cache_range(addr, size);
43 }
44 EXPORT_SYMBOL_GPL(arch_wb_cache_pmem);
45
46 long __copy_user_flushcache(void *dst, const v
47 {
48 unsigned long flushed, dest = (unsigne
49 long rc;
50
51 stac();
52 rc = __copy_user_nocache(dst, src, siz
53 clac();
54
55 /*
56 * __copy_user_nocache() uses non-temp
57 * of the transfer, but we need to man
58 * transfer is unaligned. A cached mem
59 * destination or size is not naturall
60 * - Require 8-byte alignment when s
61 * - Require 4-byte alignment when s
62 */
63 if (size < 8) {
64 if (!IS_ALIGNED(dest, 4) || si
65 clean_cache_range(dst,
66 } else {
67 if (!IS_ALIGNED(dest, 8)) {
68 dest = ALIGN(dest, boo
69 clean_cache_range(dst,
70 }
71
72 flushed = dest - (unsigned lon
73 if (size > flushed && !IS_ALIG
74 clean_cache_range(dst
75 }
76
77 return rc;
78 }
79
80 void __memcpy_flushcache(void *_dst, const voi
81 {
82 unsigned long dest = (unsigned long) _
83 unsigned long source = (unsigned long)
84
85 /* cache copy and flush to align dest
86 if (!IS_ALIGNED(dest, 8)) {
87 size_t len = min_t(size_t, siz
88
89 memcpy((void *) dest, (void *)
90 clean_cache_range((void *) des
91 dest += len;
92 source += len;
93 size -= len;
94 if (!size)
95 return;
96 }
97
98 /* 4x8 movnti loop */
99 while (size >= 32) {
100 asm("movq (%0), %%r8\n"
101 "movq 8(%0), %%r9\n"
102 "movq 16(%0), %%r10\n"
103 "movq 24(%0), %%r11\n"
104 "movnti %%r8, (%1)\n"
105 "movnti %%r9, 8(%1)\n"
106 "movnti %%r10, 16(%1)\n"
107 "movnti %%r11, 24(%1)\n"
108 :: "r" (source), "r" (dest
109 : "memory", "r8", "r9", "r
110 dest += 32;
111 source += 32;
112 size -= 32;
113 }
114
115 /* 1x8 movnti loop */
116 while (size >= 8) {
117 asm("movq (%0), %%r8\n"
118 "movnti %%r8, (%1)\n"
119 :: "r" (source), "r" (dest
120 : "memory", "r8");
121 dest += 8;
122 source += 8;
123 size -= 8;
124 }
125
126 /* 1x4 movnti loop */
127 while (size >= 4) {
128 asm("movl (%0), %%r8d\n"
129 "movnti %%r8d, (%1)\n"
130 :: "r" (source), "r" (dest
131 : "memory", "r8");
132 dest += 4;
133 source += 4;
134 size -= 4;
135 }
136
137 /* cache copy for remaining bytes */
138 if (size) {
139 memcpy((void *) dest, (void *)
140 clean_cache_range((void *) des
141 }
142 }
143 EXPORT_SYMBOL_GPL(__memcpy_flushcache);
144 #endif
145
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