2 * Copyright (c) 2015 The FreeBSD Foundation
4 * This software was developed by Andrew Turner under
5 * sponsorship from the FreeBSD Foundation.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 #include <machine/asm.h>
31 __FBSDID("$FreeBSD$");
33 #include <sys/errno.h>
35 #include <machine/vmparam.h>
39 .macro check_user_access user_arg, size_arg, bad_access_func
40 adds x6, x\user_arg, x\size_arg
42 ldr x7, =VM_MAXUSER_ADDRESS
48 * Fault handler for the copy{in,out} functions below.
51 SET_FAULT_HANDLER(xzr, x1) /* Clear the handler */
52 EXIT_USER_ACCESS_CHECK(w0, x1)
59 * Copies from a kernel to user address
61 * int copyout(const void *kaddr, void *udaddr, size_t len)
65 check_user_access 1, 2, copyio_fault_nopcb
69 1: mov x0, xzr /* return 0 */
75 * Copies from a user to kernel address
77 * int copyin(const void *uaddr, void *kdaddr, size_t len)
81 check_user_access 0, 2, copyio_fault_nopcb
85 1: mov x0, xzr /* return 0 */
91 * Copies a string from a user to kernel address
93 * int copyinstr(const void *udaddr, void *kaddr, size_t len, size_t *done)
96 mov x5, xzr /* count = 0 */
97 mov w4, #1 /* If zero return faulure */
98 cbz x2, 3f /* If len == 0 then skip loop */
100 adr x6, copyio_fault /* Get the handler address */
101 SET_FAULT_HANDLER(x6, x7) /* Set the handler */
103 ldr x7, =VM_MAXUSER_ADDRESS
106 ldtrb w4, [x0] /* Load from uaddr */
107 add x0, x0, #1 /* Next char */
108 strb w4, [x1], #1 /* Store in kaddr */
109 add x5, x5, #1 /* count++ */
110 cbz w4, 2f /* Break when NUL-terminated */
111 sub x2, x2, #1 /* len-- */
114 2: SET_FAULT_HANDLER(xzr, x7) /* Clear the handler */
117 3: cbz x3, 4f /* Check if done != NULL */
118 str x5, [x3] /* done = count */
120 4: mov w1, #ENAMETOOLONG /* Load ENAMETOOLONG to return if failed */
121 cmp w4, #0 /* Check if we saved the NUL-terminator */
122 csel w0, wzr, w1, eq /* If so return success, else failure */
132 * lr - the return address, so jump here instead of calling
134 * This function is optimized to minimize concurrent memory accesses. In
135 * present form it is suited for cores with a single memory prefetching
138 * Consider using separate functions for each ARM64 core. Adding memory
139 * access interleaving might increase a total throughput on A57 or A72.
144 .type copycommon,@function
147 adr x6, copyio_fault /* Get the handler address */
148 SET_FAULT_HANDLER(x6, x7) /* Set the handler */
149 ENTER_USER_ACCESS(w6, x7)
151 /* Check alignment */
156 /* Unaligned is byte by byte copy */
173 ldp x3, x4, [x0], #0x10
174 ldp x5, x6, [x0], #0x10
175 ldp x7, x8, [x0], #0x10
176 ldp x9, x10, [x0], #0x10
177 stp x3, x4, [x1], #0x10
178 stp x5, x6, [x1], #0x10
179 stp x7, x8, [x1], #0x10
180 stp x9, x10, [x1], #0x10
191 ldp x3, x4, [x0], #0x10
192 stp x3, x4, [x1], #0x10
196 /* Less than 16 bytes to copy */
198 tbz x2, #0x03, last_word
203 tbz x2, #0x02, last_hword
208 tbz x2, #0x01, last_byte
213 tbz x2, #0x00, ending
218 EXIT_USER_ACCESS_CHECK(w6, x7)
219 SET_FAULT_HANDLER(xzr, x7) /* Clear the handler */
221 mov x0, xzr /* return 0 */
223 .size copycommon, . - copycommon