Commit | Line | Data |
---|---|---|
457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
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 | */ | |
e683014c | 9 | #include <linux/export.h> |
13d4ea09 | 10 | #include <linux/uaccess.h> |
0aed55af | 11 | #include <linux/highmem.h> |
1da177e4 | 12 | |
1da177e4 LT |
13 | /* |
14 | * Zero Userspace | |
15 | */ | |
16 | ||
17 | unsigned long __clear_user(void __user *addr, unsigned long size) | |
18 | { | |
19 | long __d0; | |
3ee1afa3 | 20 | might_fault(); |
1da177e4 LT |
21 | /* no memory constraint because it doesn't change any memory gcc knows |
22 | about */ | |
63bcff2a | 23 | stac(); |
1da177e4 LT |
24 | asm volatile( |
25 | " testq %[size8],%[size8]\n" | |
26 | " jz 4f\n" | |
11539337 AD |
27 | "0: movq $0,(%[dst])\n" |
28 | " addq $8,%[dst]\n" | |
1da177e4 LT |
29 | " decl %%ecx ; jnz 0b\n" |
30 | "4: movq %[size1],%%rcx\n" | |
31 | " testl %%ecx,%%ecx\n" | |
32 | " jz 2f\n" | |
11539337 | 33 | "1: movb $0,(%[dst])\n" |
1da177e4 LT |
34 | " incq %[dst]\n" |
35 | " decl %%ecx ; jnz 1b\n" | |
36 | "2:\n" | |
37 | ".section .fixup,\"ax\"\n" | |
38 | "3: lea 0(%[size1],%[size8],8),%[size8]\n" | |
39 | " jmp 2b\n" | |
40 | ".previous\n" | |
75045f77 JH |
41 | _ASM_EXTABLE_UA(0b, 3b) |
42 | _ASM_EXTABLE_UA(1b, 2b) | |
e0a96129 | 43 | : [size8] "=&c"(size), [dst] "=&D" (__d0) |
11539337 | 44 | : [size1] "r"(size & 7), "[size8]" (size / 8), "[dst]"(addr)); |
63bcff2a | 45 | clac(); |
1da177e4 LT |
46 | return size; |
47 | } | |
2ee60e17 | 48 | EXPORT_SYMBOL(__clear_user); |
1da177e4 LT |
49 | |
50 | unsigned long clear_user(void __user *to, unsigned long n) | |
51 | { | |
96d4f267 | 52 | if (access_ok(to, n)) |
1da177e4 LT |
53 | return __clear_user(to, n); |
54 | return n; | |
55 | } | |
2ee60e17 | 56 | EXPORT_SYMBOL(clear_user); |
1da177e4 | 57 | |
12c89130 DW |
58 | /* |
59 | * Similar to copy_user_handle_tail, probe for the write fault point, | |
60 | * but reuse __memcpy_mcsafe in case a new read error is encountered. | |
61 | * clac() is handled in _copy_to_iter_mcsafe(). | |
62 | */ | |
63 | __visible unsigned long | |
64 | mcsafe_handle_tail(char *to, char *from, unsigned len) | |
65 | { | |
66 | for (; len; --len, to++, from++) { | |
67 | /* | |
68 | * Call the assembly routine back directly since | |
69 | * memcpy_mcsafe() may silently fallback to memcpy. | |
70 | */ | |
71 | unsigned long rem = __memcpy_mcsafe(to, from, 1); | |
72 | ||
73 | if (rem) | |
74 | break; | |
75 | } | |
76 | return len; | |
77 | } | |
78 | ||
0aed55af DW |
79 | #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE |
80 | /** | |
81 | * clean_cache_range - write back a cache range with CLWB | |
82 | * @vaddr: virtual start address | |
83 | * @size: number of bytes to write back | |
84 | * | |
85 | * Write back a cache range using the CLWB (cache line write back) | |
86 | * instruction. Note that @size is internally rounded up to be cache | |
87 | * line size aligned. | |
88 | */ | |
89 | static void clean_cache_range(void *addr, size_t size) | |
90 | { | |
91 | u16 x86_clflush_size = boot_cpu_data.x86_clflush_size; | |
92 | unsigned long clflush_mask = x86_clflush_size - 1; | |
93 | void *vend = addr + size; | |
94 | void *p; | |
95 | ||
96 | for (p = (void *)((unsigned long)addr & ~clflush_mask); | |
97 | p < vend; p += x86_clflush_size) | |
98 | clwb(p); | |
99 | } | |
100 | ||
4e4f00a9 DW |
101 | void arch_wb_cache_pmem(void *addr, size_t size) |
102 | { | |
103 | clean_cache_range(addr, size); | |
104 | } | |
105 | EXPORT_SYMBOL_GPL(arch_wb_cache_pmem); | |
106 | ||
0aed55af DW |
107 | long __copy_user_flushcache(void *dst, const void __user *src, unsigned size) |
108 | { | |
109 | unsigned long flushed, dest = (unsigned long) dst; | |
110 | long rc = __copy_user_nocache(dst, src, size, 0); | |
111 | ||
112 | /* | |
113 | * __copy_user_nocache() uses non-temporal stores for the bulk | |
114 | * of the transfer, but we need to manually flush if the | |
115 | * transfer is unaligned. A cached memory copy is used when | |
116 | * destination or size is not naturally aligned. That is: | |
117 | * - Require 8-byte alignment when size is 8 bytes or larger. | |
118 | * - Require 4-byte alignment when size is 4 bytes. | |
119 | */ | |
120 | if (size < 8) { | |
121 | if (!IS_ALIGNED(dest, 4) || size != 4) | |
122 | clean_cache_range(dst, 1); | |
123 | } else { | |
124 | if (!IS_ALIGNED(dest, 8)) { | |
125 | dest = ALIGN(dest, boot_cpu_data.x86_clflush_size); | |
126 | clean_cache_range(dst, 1); | |
127 | } | |
128 | ||
129 | flushed = dest - (unsigned long) dst; | |
130 | if (size > flushed && !IS_ALIGNED(size - flushed, 8)) | |
131 | clean_cache_range(dst + size - 1, 1); | |
132 | } | |
133 | ||
134 | return rc; | |
135 | } | |
136 | ||
02101c45 | 137 | void __memcpy_flushcache(void *_dst, const void *_src, size_t size) |
0aed55af DW |
138 | { |
139 | unsigned long dest = (unsigned long) _dst; | |
140 | unsigned long source = (unsigned long) _src; | |
141 | ||
142 | /* cache copy and flush to align dest */ | |
143 | if (!IS_ALIGNED(dest, 8)) { | |
144 | unsigned len = min_t(unsigned, size, ALIGN(dest, 8) - dest); | |
145 | ||
146 | memcpy((void *) dest, (void *) source, len); | |
147 | clean_cache_range((void *) dest, len); | |
148 | dest += len; | |
149 | source += len; | |
150 | size -= len; | |
151 | if (!size) | |
152 | return; | |
153 | } | |
154 | ||
155 | /* 4x8 movnti loop */ | |
156 | while (size >= 32) { | |
157 | asm("movq (%0), %%r8\n" | |
158 | "movq 8(%0), %%r9\n" | |
159 | "movq 16(%0), %%r10\n" | |
160 | "movq 24(%0), %%r11\n" | |
161 | "movnti %%r8, (%1)\n" | |
162 | "movnti %%r9, 8(%1)\n" | |
163 | "movnti %%r10, 16(%1)\n" | |
164 | "movnti %%r11, 24(%1)\n" | |
165 | :: "r" (source), "r" (dest) | |
166 | : "memory", "r8", "r9", "r10", "r11"); | |
167 | dest += 32; | |
168 | source += 32; | |
169 | size -= 32; | |
170 | } | |
171 | ||
172 | /* 1x8 movnti loop */ | |
173 | while (size >= 8) { | |
174 | asm("movq (%0), %%r8\n" | |
175 | "movnti %%r8, (%1)\n" | |
176 | :: "r" (source), "r" (dest) | |
177 | : "memory", "r8"); | |
178 | dest += 8; | |
179 | source += 8; | |
180 | size -= 8; | |
181 | } | |
182 | ||
183 | /* 1x4 movnti loop */ | |
184 | while (size >= 4) { | |
185 | asm("movl (%0), %%r8d\n" | |
186 | "movnti %%r8d, (%1)\n" | |
187 | :: "r" (source), "r" (dest) | |
188 | : "memory", "r8"); | |
189 | dest += 4; | |
190 | source += 4; | |
191 | size -= 4; | |
192 | } | |
193 | ||
194 | /* cache copy for remaining bytes */ | |
195 | if (size) { | |
196 | memcpy((void *) dest, (void *) source, size); | |
197 | clean_cache_range((void *) dest, size); | |
198 | } | |
199 | } | |
02101c45 | 200 | EXPORT_SYMBOL_GPL(__memcpy_flushcache); |
0aed55af DW |
201 | |
202 | void memcpy_page_flushcache(char *to, struct page *page, size_t offset, | |
203 | size_t len) | |
204 | { | |
205 | char *from = kmap_atomic(page); | |
206 | ||
207 | memcpy_flushcache(to, from + offset, len); | |
208 | kunmap_atomic(from); | |
209 | } | |
210 | #endif |