1 /*
2  * Copyright (c) 2015, Linaro Limited
3  *
4  * This software is licensed under the terms of the GNU General Public
5  * License version 2, as published by the Free Software Foundation, and
6  * may be copied, distributed, and modified under those terms.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  *
13  */
14 #ifndef __LINUX_ARM_SMCCC_H
15 #define __LINUX_ARM_SMCCC_H
16 
17 #include <uapi/linux/const.h>
18 
19 /*
20  * This file provides common defines for ARM SMC Calling Convention as
21  * specified in
22  * http://infocenter.arm.com/help/topic/com.arm.doc.den0028a/index.html
23  */
24 
25 #define ARM_SMCCC_STD_CALL	        _AC(0,U)
26 #define ARM_SMCCC_FAST_CALL	        _AC(1,U)
27 #define ARM_SMCCC_TYPE_SHIFT		31
28 
29 #define ARM_SMCCC_SMC_32		0
30 #define ARM_SMCCC_SMC_64		1
31 #define ARM_SMCCC_CALL_CONV_SHIFT	30
32 
33 #define ARM_SMCCC_OWNER_MASK		0x3F
34 #define ARM_SMCCC_OWNER_SHIFT		24
35 
36 #define ARM_SMCCC_FUNC_MASK		0xFFFF
37 
38 #define ARM_SMCCC_IS_FAST_CALL(smc_val)	\
39 	((smc_val) & (ARM_SMCCC_FAST_CALL << ARM_SMCCC_TYPE_SHIFT))
40 #define ARM_SMCCC_IS_64(smc_val) \
41 	((smc_val) & (ARM_SMCCC_SMC_64 << ARM_SMCCC_CALL_CONV_SHIFT))
42 #define ARM_SMCCC_FUNC_NUM(smc_val)	((smc_val) & ARM_SMCCC_FUNC_MASK)
43 #define ARM_SMCCC_OWNER_NUM(smc_val) \
44 	(((smc_val) >> ARM_SMCCC_OWNER_SHIFT) & ARM_SMCCC_OWNER_MASK)
45 
46 #define ARM_SMCCC_CALL_VAL(type, calling_convention, owner, func_num) \
47 	(((type) << ARM_SMCCC_TYPE_SHIFT) | \
48 	((calling_convention) << ARM_SMCCC_CALL_CONV_SHIFT) | \
49 	(((owner) & ARM_SMCCC_OWNER_MASK) << ARM_SMCCC_OWNER_SHIFT) | \
50 	((func_num) & ARM_SMCCC_FUNC_MASK))
51 
52 #define ARM_SMCCC_OWNER_ARCH		0
53 #define ARM_SMCCC_OWNER_CPU		1
54 #define ARM_SMCCC_OWNER_SIP		2
55 #define ARM_SMCCC_OWNER_OEM		3
56 #define ARM_SMCCC_OWNER_STANDARD	4
57 #define ARM_SMCCC_OWNER_TRUSTED_APP	48
58 #define ARM_SMCCC_OWNER_TRUSTED_APP_END	49
59 #define ARM_SMCCC_OWNER_TRUSTED_OS	50
60 #define ARM_SMCCC_OWNER_TRUSTED_OS_END	63
61 
62 #define ARM_SMCCC_QUIRK_NONE		0
63 #define ARM_SMCCC_QUIRK_QCOM_A6		1 /* Save/restore register a6 */
64 
65 #define ARM_SMCCC_VERSION_1_0		0x10000
66 #define ARM_SMCCC_VERSION_1_1		0x10001
67 
68 #define ARM_SMCCC_VERSION_FUNC_ID					\
69 	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,				\
70 			   ARM_SMCCC_SMC_32,				\
71 			   0, 0)
72 
73 #define ARM_SMCCC_ARCH_FEATURES_FUNC_ID					\
74 	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,				\
75 			   ARM_SMCCC_SMC_32,				\
76 			   0, 1)
77 
78 #define ARM_SMCCC_ARCH_WORKAROUND_1					\
79 	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,				\
80 			   ARM_SMCCC_SMC_32,				\
81 			   0, 0x8000)
82 
83 #define ARM_SMCCC_ARCH_WORKAROUND_2					\
84 	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,				\
85 			   ARM_SMCCC_SMC_32,				\
86 			   0, 0x7fff)
87 
88 #define ARM_SMCCC_ARCH_WORKAROUND_3					\
89 	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,				\
90 			   ARM_SMCCC_SMC_32,				\
91 			   0, 0x3fff)
92 
93 #define SMCCC_ARCH_WORKAROUND_RET_UNAFFECTED	1
94 
95 #ifndef __ASSEMBLY__
96 
97 #include <linux/linkage.h>
98 #include <linux/types.h>
99 
100 enum arm_smccc_conduit {
101 	SMCCC_CONDUIT_NONE,
102 	SMCCC_CONDUIT_SMC,
103 	SMCCC_CONDUIT_HVC,
104 };
105 
106 /**
107  * arm_smccc_1_1_get_conduit()
108  *
109  * Returns the conduit to be used for SMCCCv1.1 or later.
110  *
111  * When SMCCCv1.1 is not present, returns SMCCC_CONDUIT_NONE.
112  */
113 enum arm_smccc_conduit arm_smccc_1_1_get_conduit(void);
114 
115 /**
116  * struct arm_smccc_res - Result from SMC/HVC call
117  * @a0-a3 result values from registers 0 to 3
118  */
119 struct arm_smccc_res {
120 	unsigned long a0;
121 	unsigned long a1;
122 	unsigned long a2;
123 	unsigned long a3;
124 };
125 
126 /**
127  * struct arm_smccc_quirk - Contains quirk information
128  * @id: quirk identification
129  * @state: quirk specific information
130  * @a6: Qualcomm quirk entry for returning post-smc call contents of a6
131  */
132 struct arm_smccc_quirk {
133 	int	id;
134 	union {
135 		unsigned long a6;
136 	} state;
137 };
138 
139 /**
140  * __arm_smccc_smc() - make SMC calls
141  * @a0-a7: arguments passed in registers 0 to 7
142  * @res: result values from registers 0 to 3
143  * @quirk: points to an arm_smccc_quirk, or NULL when no quirks are required.
144  *
145  * This function is used to make SMC calls following SMC Calling Convention.
146  * The content of the supplied param are copied to registers 0 to 7 prior
147  * to the SMC instruction. The return values are updated with the content
148  * from register 0 to 3 on return from the SMC instruction.  An optional
149  * quirk structure provides vendor specific behavior.
150  */
151 asmlinkage void __arm_smccc_smc(unsigned long a0, unsigned long a1,
152 			unsigned long a2, unsigned long a3, unsigned long a4,
153 			unsigned long a5, unsigned long a6, unsigned long a7,
154 			struct arm_smccc_res *res, struct arm_smccc_quirk *quirk);
155 
156 /**
157  * __arm_smccc_hvc() - make HVC calls
158  * @a0-a7: arguments passed in registers 0 to 7
159  * @res: result values from registers 0 to 3
160  * @quirk: points to an arm_smccc_quirk, or NULL when no quirks are required.
161  *
162  * This function is used to make HVC calls following SMC Calling
163  * Convention.  The content of the supplied param are copied to registers 0
164  * to 7 prior to the HVC instruction. The return values are updated with
165  * the content from register 0 to 3 on return from the HVC instruction.  An
166  * optional quirk structure provides vendor specific behavior.
167  */
168 asmlinkage void __arm_smccc_hvc(unsigned long a0, unsigned long a1,
169 			unsigned long a2, unsigned long a3, unsigned long a4,
170 			unsigned long a5, unsigned long a6, unsigned long a7,
171 			struct arm_smccc_res *res, struct arm_smccc_quirk *quirk);
172 
173 #define arm_smccc_smc(...) __arm_smccc_smc(__VA_ARGS__, NULL)
174 
175 #define arm_smccc_smc_quirk(...) __arm_smccc_smc(__VA_ARGS__)
176 
177 #define arm_smccc_hvc(...) __arm_smccc_hvc(__VA_ARGS__, NULL)
178 
179 #define arm_smccc_hvc_quirk(...) __arm_smccc_hvc(__VA_ARGS__)
180 
181 /* SMCCC v1.1 implementation madness follows */
182 #ifdef CONFIG_ARM64
183 
184 #define SMCCC_SMC_INST	"smc	#0"
185 #define SMCCC_HVC_INST	"hvc	#0"
186 
187 #elif defined(CONFIG_ARM)
188 #include <asm/opcodes-sec.h>
189 #include <asm/opcodes-virt.h>
190 
191 #define SMCCC_SMC_INST	__SMC(0)
192 #define SMCCC_HVC_INST	__HVC(0)
193 
194 #endif
195 
196 #define ___count_args(_0, _1, _2, _3, _4, _5, _6, _7, _8, x, ...) x
197 
198 #define __count_args(...)						\
199 	___count_args(__VA_ARGS__, 7, 6, 5, 4, 3, 2, 1, 0)
200 
201 #define __constraint_write_0						\
202 	"+r" (r0), "=&r" (r1), "=&r" (r2), "=&r" (r3)
203 #define __constraint_write_1						\
204 	"+r" (r0), "+r" (r1), "=&r" (r2), "=&r" (r3)
205 #define __constraint_write_2						\
206 	"+r" (r0), "+r" (r1), "+r" (r2), "=&r" (r3)
207 #define __constraint_write_3						\
208 	"+r" (r0), "+r" (r1), "+r" (r2), "+r" (r3)
209 #define __constraint_write_4	__constraint_write_3
210 #define __constraint_write_5	__constraint_write_4
211 #define __constraint_write_6	__constraint_write_5
212 #define __constraint_write_7	__constraint_write_6
213 
214 #define __constraint_read_0
215 #define __constraint_read_1
216 #define __constraint_read_2
217 #define __constraint_read_3
218 #define __constraint_read_4	"r" (r4)
219 #define __constraint_read_5	__constraint_read_4, "r" (r5)
220 #define __constraint_read_6	__constraint_read_5, "r" (r6)
221 #define __constraint_read_7	__constraint_read_6, "r" (r7)
222 
223 #define __declare_arg_0(a0, res)					\
224 	struct arm_smccc_res   *___res = res;				\
225 	register unsigned long r0 asm("r0") = (u32)a0;			\
226 	register unsigned long r1 asm("r1");				\
227 	register unsigned long r2 asm("r2");				\
228 	register unsigned long r3 asm("r3")
229 
230 #define __declare_arg_1(a0, a1, res)					\
231 	typeof(a1) __a1 = a1;						\
232 	struct arm_smccc_res   *___res = res;				\
233 	register unsigned long r0 asm("r0") = (u32)a0;			\
234 	register unsigned long r1 asm("r1") = __a1;			\
235 	register unsigned long r2 asm("r2");				\
236 	register unsigned long r3 asm("r3")
237 
238 #define __declare_arg_2(a0, a1, a2, res)				\
239 	typeof(a1) __a1 = a1;						\
240 	typeof(a2) __a2 = a2;						\
241 	struct arm_smccc_res   *___res = res;				\
242 	register unsigned long r0 asm("r0") = (u32)a0;			\
243 	register unsigned long r1 asm("r1") = __a1;			\
244 	register unsigned long r2 asm("r2") = __a2;			\
245 	register unsigned long r3 asm("r3")
246 
247 #define __declare_arg_3(a0, a1, a2, a3, res)				\
248 	typeof(a1) __a1 = a1;						\
249 	typeof(a2) __a2 = a2;						\
250 	typeof(a3) __a3 = a3;						\
251 	struct arm_smccc_res   *___res = res;				\
252 	register unsigned long r0 asm("r0") = (u32)a0;			\
253 	register unsigned long r1 asm("r1") = __a1;			\
254 	register unsigned long r2 asm("r2") = __a2;			\
255 	register unsigned long r3 asm("r3") = __a3
256 
257 #define __declare_arg_4(a0, a1, a2, a3, a4, res)			\
258 	typeof(a4) __a4 = a4;						\
259 	__declare_arg_3(a0, a1, a2, a3, res);				\
260 	register unsigned long r4 asm("r4") = __a4
261 
262 #define __declare_arg_5(a0, a1, a2, a3, a4, a5, res)			\
263 	typeof(a5) __a5 = a5;						\
264 	__declare_arg_4(a0, a1, a2, a3, a4, res);			\
265 	register unsigned long r5 asm("r5") = __a5
266 
267 #define __declare_arg_6(a0, a1, a2, a3, a4, a5, a6, res)		\
268 	typeof(a6) __a6 = a6;						\
269 	__declare_arg_5(a0, a1, a2, a3, a4, a5, res);			\
270 	register unsigned long r6 asm("r6") = __a6
271 
272 #define __declare_arg_7(a0, a1, a2, a3, a4, a5, a6, a7, res)		\
273 	typeof(a7) __a7 = a7;						\
274 	__declare_arg_6(a0, a1, a2, a3, a4, a5, a6, res);		\
275 	register unsigned long r7 asm("r7") = __a7
276 
277 #define ___declare_args(count, ...) __declare_arg_ ## count(__VA_ARGS__)
278 #define __declare_args(count, ...)  ___declare_args(count, __VA_ARGS__)
279 
280 #define ___constraints(count)						\
281 	: __constraint_write_ ## count					\
282 	: __constraint_read_ ## count					\
283 	: "memory"
284 #define __constraints(count)	___constraints(count)
285 
286 /*
287  * We have an output list that is not necessarily used, and GCC feels
288  * entitled to optimise the whole sequence away. "volatile" is what
289  * makes it stick.
290  */
291 #define __arm_smccc_1_1(inst, ...)					\
292 	do {								\
293 		__declare_args(__count_args(__VA_ARGS__), __VA_ARGS__);	\
294 		asm volatile(inst "\n"					\
295 			     __constraints(__count_args(__VA_ARGS__)));	\
296 		if (___res)						\
297 			*___res = (typeof(*___res)){r0, r1, r2, r3};	\
298 	} while (0)
299 
300 /*
301  * arm_smccc_1_1_smc() - make an SMCCC v1.1 compliant SMC call
302  *
303  * This is a variadic macro taking one to eight source arguments, and
304  * an optional return structure.
305  *
306  * @a0-a7: arguments passed in registers 0 to 7
307  * @res: result values from registers 0 to 3
308  *
309  * This macro is used to make SMC calls following SMC Calling Convention v1.1.
310  * The content of the supplied param are copied to registers 0 to 7 prior
311  * to the SMC instruction. The return values are updated with the content
312  * from register 0 to 3 on return from the SMC instruction if not NULL.
313  */
314 #define arm_smccc_1_1_smc(...)	__arm_smccc_1_1(SMCCC_SMC_INST, __VA_ARGS__)
315 
316 /*
317  * arm_smccc_1_1_hvc() - make an SMCCC v1.1 compliant HVC call
318  *
319  * This is a variadic macro taking one to eight source arguments, and
320  * an optional return structure.
321  *
322  * @a0-a7: arguments passed in registers 0 to 7
323  * @res: result values from registers 0 to 3
324  *
325  * This macro is used to make HVC calls following SMC Calling Convention v1.1.
326  * The content of the supplied param are copied to registers 0 to 7 prior
327  * to the HVC instruction. The return values are updated with the content
328  * from register 0 to 3 on return from the HVC instruction if not NULL.
329  */
330 #define arm_smccc_1_1_hvc(...)	__arm_smccc_1_1(SMCCC_HVC_INST, __VA_ARGS__)
331 
332 /* Return codes defined in ARM DEN 0070A */
333 #define SMCCC_RET_SUCCESS			0
334 #define SMCCC_RET_NOT_SUPPORTED			-1
335 #define SMCCC_RET_NOT_REQUIRED			-2
336 
337 /*
338  * Like arm_smccc_1_1* but always returns SMCCC_RET_NOT_SUPPORTED.
339  * Used when the SMCCC conduit is not defined. The empty asm statement
340  * avoids compiler warnings about unused variables.
341  */
342 #define __fail_smccc_1_1(...)						\
343 	do {								\
344 		__declare_args(__count_args(__VA_ARGS__), __VA_ARGS__);	\
345 		asm ("" __constraints(__count_args(__VA_ARGS__)));	\
346 		if (___res)						\
347 			___res->a0 = SMCCC_RET_NOT_SUPPORTED;		\
348 	} while (0)
349 
350 /*
351  * arm_smccc_1_1_invoke() - make an SMCCC v1.1 compliant call
352  *
353  * This is a variadic macro taking one to eight source arguments, and
354  * an optional return structure.
355  *
356  * @a0-a7: arguments passed in registers 0 to 7
357  * @res: result values from registers 0 to 3
358  *
359  * This macro will make either an HVC call or an SMC call depending on the
360  * current SMCCC conduit. If no valid conduit is available then -1
361  * (SMCCC_RET_NOT_SUPPORTED) is returned in @res.a0 (if supplied).
362  *
363  * The return value also provides the conduit that was used.
364  */
365 #define arm_smccc_1_1_invoke(...) ({					\
366 		int method = arm_smccc_1_1_get_conduit();		\
367 		switch (method) {					\
368 		case SMCCC_CONDUIT_HVC:					\
369 			arm_smccc_1_1_hvc(__VA_ARGS__);			\
370 			break;						\
371 		case SMCCC_CONDUIT_SMC:					\
372 			arm_smccc_1_1_smc(__VA_ARGS__);			\
373 			break;						\
374 		default:						\
375 			__fail_smccc_1_1(__VA_ARGS__);			\
376 			method = SMCCC_CONDUIT_NONE;			\
377 			break;						\
378 		}							\
379 		method;							\
380 	})
381 
382 /* Paravirtualised time calls (defined by ARM DEN0057A) */
383 #define ARM_SMCCC_HV_PV_TIME_FEATURES				\
384 	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,			\
385 			   ARM_SMCCC_SMC_64,			\
386 			   ARM_SMCCC_OWNER_STANDARD_HYP,	\
387 			   0x20)
388 
389 #define ARM_SMCCC_HV_PV_TIME_ST					\
390 	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,			\
391 			   ARM_SMCCC_SMC_64,			\
392 			   ARM_SMCCC_OWNER_STANDARD_HYP,	\
393 			   0x21)
394 
395 #endif /*__ASSEMBLY__*/
396 #endif /*__LINUX_ARM_SMCCC_H*/
397