1 /*
2 * Copyright (c) 2022 Intel Corporation.
3 *
4 * SPDX-License-Identifier: Apache-2.0
5 */
6
7 /**
8 * @file
9 * @brief Xtensa specific syscall header
10 *
11 * This header contains the Xtensa specific syscall interface. It is
12 * included by the syscall interface architecture-abstraction header
13 * (include/arch/syscall.h)
14 */
15
16 #ifndef ZEPHYR_INCLUDE_ARCH_XTENSA_SYSCALL_H_
17 #define ZEPHYR_INCLUDE_ARCH_XTENSA_SYSCALL_H_
18
19 #ifdef CONFIG_USERSPACE
20 #ifndef _ASMLANGUAGE
21
22 #include <zephyr/types.h>
23 #include <stdbool.h>
24 #include <zephyr/linker/sections.h>
25 #include <zephyr/sys/util_macro.h>
26
27 #include <xtensa/config/core-isa.h>
28
29 #ifdef __cplusplus
30 extern "C" {
31 #endif
32
33 #ifdef CONFIG_XTENSA_SYSCALL_USE_HELPER
34 uintptr_t xtensa_syscall_helper(uintptr_t arg1, uintptr_t arg2,
35 uintptr_t arg3, uintptr_t arg4,
36 uintptr_t arg5, uintptr_t arg6,
37 uintptr_t call_id);
38
39 #define SYSINL ALWAYS_INLINE
40 #else
41 #define SYSINL inline
42 #endif /* CONFIG_XTENSA_SYSCALL_USE_HELPER */
43
44 /**
45 * We are following Linux Xtensa syscall ABI:
46 *
47 * syscall number arg1, arg2, arg3, arg4, arg5, arg6
48 * -------------- ----------------------------------
49 * a2 a6, a3, a4, a5, a8, a9
50 *
51 **/
52
arch_syscall_invoke6(uintptr_t arg1,uintptr_t arg2,uintptr_t arg3,uintptr_t arg4,uintptr_t arg5,uintptr_t arg6,uintptr_t call_id)53 static SYSINL uintptr_t arch_syscall_invoke6(uintptr_t arg1, uintptr_t arg2,
54 uintptr_t arg3, uintptr_t arg4,
55 uintptr_t arg5, uintptr_t arg6,
56 uintptr_t call_id)
57 {
58 #ifdef CONFIG_XTENSA_SYSCALL_USE_HELPER
59 return xtensa_syscall_helper(arg1, arg2, arg3, arg4, arg5, arg6, call_id);
60 #else
61 register uintptr_t a2 __asm__("%a2") = call_id;
62 register uintptr_t a6 __asm__("%a6") = arg1;
63 register uintptr_t a3 __asm__("%a3") = arg2;
64 register uintptr_t a4 __asm__("%a4") = arg3;
65 register uintptr_t a5 __asm__("%a5") = arg4;
66 register uintptr_t a8 __asm__("%a8") = arg5;
67 register uintptr_t a9 __asm__("%a9") = arg6;
68
69 __asm__ volatile("syscall\n\t"
70 : "=r" (a2)
71 : "r" (a2), "r" (a6), "r" (a3), "r" (a4),
72 "r" (a5), "r" (a8), "r" (a9)
73 : "memory");
74
75 return a2;
76 #endif /* CONFIG_XTENSA_SYSCALL_USE_HELPER */
77 }
78
arch_syscall_invoke5(uintptr_t arg1,uintptr_t arg2,uintptr_t arg3,uintptr_t arg4,uintptr_t arg5,uintptr_t call_id)79 static SYSINL uintptr_t arch_syscall_invoke5(uintptr_t arg1, uintptr_t arg2,
80 uintptr_t arg3, uintptr_t arg4,
81 uintptr_t arg5, uintptr_t call_id)
82 {
83 #ifdef CONFIG_XTENSA_SYSCALL_USE_HELPER
84 return xtensa_syscall_helper(arg1, arg2, arg3, arg4, arg5, 0, call_id);
85 #else
86 register uintptr_t a2 __asm__("%a2") = call_id;
87 register uintptr_t a6 __asm__("%a6") = arg1;
88 register uintptr_t a3 __asm__("%a3") = arg2;
89 register uintptr_t a4 __asm__("%a4") = arg3;
90 register uintptr_t a5 __asm__("%a5") = arg4;
91 register uintptr_t a8 __asm__("%a8") = arg5;
92
93 __asm__ volatile("syscall\n\t"
94 : "=r" (a2)
95 : "r" (a2), "r" (a6), "r" (a3), "r" (a4),
96 "r" (a5), "r" (a8)
97 : "memory");
98
99 return a2;
100 #endif /* CONFIG_XTENSA_SYSCALL_USE_HELPER */
101 }
102
arch_syscall_invoke4(uintptr_t arg1,uintptr_t arg2,uintptr_t arg3,uintptr_t arg4,uintptr_t call_id)103 static SYSINL uintptr_t arch_syscall_invoke4(uintptr_t arg1, uintptr_t arg2,
104 uintptr_t arg3, uintptr_t arg4,
105 uintptr_t call_id)
106 {
107 #ifdef CONFIG_XTENSA_SYSCALL_USE_HELPER
108 return xtensa_syscall_helper(arg1, arg2, arg3, arg4, 0, 0, call_id);
109 #else
110 register uintptr_t a2 __asm__("%a2") = call_id;
111 register uintptr_t a6 __asm__("%a6") = arg1;
112 register uintptr_t a3 __asm__("%a3") = arg2;
113 register uintptr_t a4 __asm__("%a4") = arg3;
114 register uintptr_t a5 __asm__("%a5") = arg4;
115
116 __asm__ volatile("syscall\n\t"
117 : "=r" (a2)
118 : "r" (a2), "r" (a6), "r" (a3), "r" (a4),
119 "r" (a5)
120 : "memory");
121
122 return a2;
123 #endif /* CONFIG_XTENSA_SYSCALL_USE_HELPER */
124 }
125
arch_syscall_invoke3(uintptr_t arg1,uintptr_t arg2,uintptr_t arg3,uintptr_t call_id)126 static SYSINL uintptr_t arch_syscall_invoke3(uintptr_t arg1, uintptr_t arg2,
127 uintptr_t arg3, uintptr_t call_id)
128 {
129 #ifdef CONFIG_XTENSA_SYSCALL_USE_HELPER
130 return xtensa_syscall_helper(arg1, arg2, arg3, 0, 0, 0, call_id);
131 #else
132 register uintptr_t a2 __asm__("%a2") = call_id;
133 register uintptr_t a6 __asm__("%a6") = arg1;
134 register uintptr_t a3 __asm__("%a3") = arg2;
135 register uintptr_t a4 __asm__("%a4") = arg3;
136
137 __asm__ volatile("syscall\n\t"
138 : "=r" (a2)
139 : "r" (a2), "r" (a6), "r" (a3), "r" (a4)
140 : "memory");
141
142 return a2;
143 #endif /* CONFIG_XTENSA_SYSCALL_USE_HELPER */
144 }
145
arch_syscall_invoke2(uintptr_t arg1,uintptr_t arg2,uintptr_t call_id)146 static SYSINL uintptr_t arch_syscall_invoke2(uintptr_t arg1, uintptr_t arg2,
147 uintptr_t call_id)
148 {
149 #ifdef CONFIG_XTENSA_SYSCALL_USE_HELPER
150 return xtensa_syscall_helper(arg1, arg2, 0, 0, 0, 0, call_id);
151 #else
152 register uintptr_t a2 __asm__("%a2") = call_id;
153 register uintptr_t a6 __asm__("%a6") = arg1;
154 register uintptr_t a3 __asm__("%a3") = arg2;
155
156 __asm__ volatile("syscall\n\t"
157 : "=r" (a2)
158 : "r" (a2), "r" (a6), "r" (a3)
159 : "memory");
160
161 return a2;
162 #endif
163 }
164
arch_syscall_invoke1(uintptr_t arg1,uintptr_t call_id)165 static SYSINL uintptr_t arch_syscall_invoke1(uintptr_t arg1,
166 uintptr_t call_id)
167 {
168 #ifdef CONFIG_XTENSA_SYSCALL_USE_HELPER
169 return xtensa_syscall_helper(arg1, 0, 0, 0, 0, 0, call_id);
170 #else
171 register uintptr_t a2 __asm__("%a2") = call_id;
172 register uintptr_t a6 __asm__("%a6") = arg1;
173
174 __asm__ volatile("syscall\n\t"
175 : "=r" (a2)
176 : "r" (a2), "r" (a6)
177 : "memory");
178
179 return a2;
180 #endif
181 }
182
arch_syscall_invoke0(uintptr_t call_id)183 static SYSINL uintptr_t arch_syscall_invoke0(uintptr_t call_id)
184 {
185 #ifdef CONFIG_XTENSA_SYSCALL_USE_HELPER
186 return xtensa_syscall_helper(0, 0, 0, 0, 0, 0, call_id);
187 #else
188 register uintptr_t a2 __asm__("%a2") = call_id;
189
190 __asm__ volatile("syscall\n\t"
191 : "=r" (a2)
192 : "r" (a2)
193 : "memory");
194
195 return a2;
196 #endif
197 }
198
199 /*
200 * There is no easy (or generic) way to figure out if a thread is runnining
201 * in un-privileged mode. Reading the current ring (PS.CRING) is a privileged
202 * instruction and not thread local storage is not available in xcc.
203 */
arch_is_user_context(void)204 static inline bool arch_is_user_context(void)
205 {
206 #if XCHAL_HAVE_THREADPTR
207 uint32_t thread;
208
209 __asm__ volatile(
210 "rur.THREADPTR %0\n\t"
211 : "=a" (thread)
212 );
213 #ifdef CONFIG_THREAD_LOCAL_STORAGE
214 extern __thread uint32_t is_user_mode;
215
216 if (!thread) {
217 return false;
218 }
219
220 return is_user_mode != 0;
221 #else
222 return !!thread;
223 #endif
224
225 #else /* XCHAL_HAVE_THREADPTR */
226 extern bool xtensa_is_user_context(void);
227
228 return xtensa_is_user_context();
229 #endif /* XCHAL_HAVE_THREADPTR */
230 }
231
232 #undef SYSINL
233
234 #ifdef __cplusplus
235 }
236 #endif
237
238 #endif /* _ASMLANGUAGE */
239 #endif /* CONFIG_USERSPACE */
240 #endif /* ZEPHYR_INCLUDE_ARCH_XTENSA_SYSCALL_H_ */
241
