1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (c) 2015, Linaro Limited
4  */
5 #ifndef __LINUX_ARM_SMCCC_H
6 #define __LINUX_ARM_SMCCC_H
7 
8 #include <linux/init.h>
9 #include <uapi/linux/const.h>
10 
11 /*
12  * This file provides common defines for ARM SMC Calling Convention as
13  * specified in
14  * https://developer.arm.com/docs/den0028/latest
15  *
16  * This code is up-to-date with version DEN 0028 C
17  */
18 
19 #define ARM_SMCCC_STD_CALL	        _AC(0,U)
20 #define ARM_SMCCC_FAST_CALL	        _AC(1,U)
21 #define ARM_SMCCC_TYPE_SHIFT		31
22 
23 #define ARM_SMCCC_SMC_32		0
24 #define ARM_SMCCC_SMC_64		1
25 #define ARM_SMCCC_CALL_CONV_SHIFT	30
26 
27 #define ARM_SMCCC_OWNER_MASK		0x3F
28 #define ARM_SMCCC_OWNER_SHIFT		24
29 
30 #define ARM_SMCCC_FUNC_MASK		0xFFFF
31 
32 #define ARM_SMCCC_IS_FAST_CALL(smc_val)	\
33 	((smc_val) & (ARM_SMCCC_FAST_CALL << ARM_SMCCC_TYPE_SHIFT))
34 #define ARM_SMCCC_IS_64(smc_val) \
35 	((smc_val) & (ARM_SMCCC_SMC_64 << ARM_SMCCC_CALL_CONV_SHIFT))
36 #define ARM_SMCCC_FUNC_NUM(smc_val)	((smc_val) & ARM_SMCCC_FUNC_MASK)
37 #define ARM_SMCCC_OWNER_NUM(smc_val) \
38 	(((smc_val) >> ARM_SMCCC_OWNER_SHIFT) & ARM_SMCCC_OWNER_MASK)
39 
40 #define ARM_SMCCC_CALL_VAL(type, calling_convention, owner, func_num) \
41 	(((type) << ARM_SMCCC_TYPE_SHIFT) | \
42 	((calling_convention) << ARM_SMCCC_CALL_CONV_SHIFT) | \
43 	(((owner) & ARM_SMCCC_OWNER_MASK) << ARM_SMCCC_OWNER_SHIFT) | \
44 	((func_num) & ARM_SMCCC_FUNC_MASK))
45 
46 #define ARM_SMCCC_OWNER_ARCH		0
47 #define ARM_SMCCC_OWNER_CPU		1
48 #define ARM_SMCCC_OWNER_SIP		2
49 #define ARM_SMCCC_OWNER_OEM		3
50 #define ARM_SMCCC_OWNER_STANDARD	4
51 #define ARM_SMCCC_OWNER_STANDARD_HYP	5
52 #define ARM_SMCCC_OWNER_VENDOR_HYP	6
53 #define ARM_SMCCC_OWNER_TRUSTED_APP	48
54 #define ARM_SMCCC_OWNER_TRUSTED_APP_END	49
55 #define ARM_SMCCC_OWNER_TRUSTED_OS	50
56 #define ARM_SMCCC_OWNER_TRUSTED_OS_END	63
57 
58 #define ARM_SMCCC_QUIRK_NONE		0
59 #define ARM_SMCCC_QUIRK_QCOM_A6		1 /* Save/restore register a6 */
60 
61 #define ARM_SMCCC_VERSION_1_0		0x10000
62 #define ARM_SMCCC_VERSION_1_1		0x10001
63 #define ARM_SMCCC_VERSION_1_2		0x10002
64 
65 #define ARM_SMCCC_VERSION_FUNC_ID					\
66 	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,				\
67 			   ARM_SMCCC_SMC_32,				\
68 			   0, 0)
69 
70 #define ARM_SMCCC_ARCH_FEATURES_FUNC_ID					\
71 	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,				\
72 			   ARM_SMCCC_SMC_32,				\
73 			   0, 1)
74 
75 #define ARM_SMCCC_ARCH_SOC_ID						\
76 	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,				\
77 			   ARM_SMCCC_SMC_32,				\
78 			   0, 2)
79 
80 #define ARM_SMCCC_ARCH_WORKAROUND_1					\
81 	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,				\
82 			   ARM_SMCCC_SMC_32,				\
83 			   0, 0x8000)
84 
85 #define ARM_SMCCC_ARCH_WORKAROUND_2					\
86 	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,				\
87 			   ARM_SMCCC_SMC_32,				\
88 			   0, 0x7fff)
89 
90 #define SMCCC_ARCH_WORKAROUND_RET_UNAFFECTED	1
91 
92 /* Paravirtualised time calls (defined by ARM DEN0057A) */
93 #define ARM_SMCCC_HV_PV_TIME_FEATURES				\
94 	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,			\
95 			   ARM_SMCCC_SMC_64,			\
96 			   ARM_SMCCC_OWNER_STANDARD_HYP,	\
97 			   0x20)
98 
99 #define ARM_SMCCC_HV_PV_TIME_ST					\
100 	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,			\
101 			   ARM_SMCCC_SMC_64,			\
102 			   ARM_SMCCC_OWNER_STANDARD_HYP,	\
103 			   0x21)
104 
105 /*
106  * Return codes defined in ARM DEN 0070A
107  * ARM DEN 0070A is now merged/consolidated into ARM DEN 0028 C
108  */
109 #define SMCCC_RET_SUCCESS			0
110 #define SMCCC_RET_NOT_SUPPORTED			-1
111 #define SMCCC_RET_NOT_REQUIRED			-2
112 #define SMCCC_RET_INVALID_PARAMETER		-3
113 
114 #ifndef __ASSEMBLY__
115 
116 #include <linux/linkage.h>
117 #include <linux/types.h>
118 
119 enum arm_smccc_conduit {
120 	SMCCC_CONDUIT_NONE,
121 	SMCCC_CONDUIT_SMC,
122 	SMCCC_CONDUIT_HVC,
123 };
124 
125 /**
126  * arm_smccc_1_1_get_conduit()
127  *
128  * Returns the conduit to be used for SMCCCv1.1 or later.
129  *
130  * When SMCCCv1.1 is not present, returns SMCCC_CONDUIT_NONE.
131  */
132 enum arm_smccc_conduit arm_smccc_1_1_get_conduit(void);
133 
134 /**
135  * arm_smccc_get_version()
136  *
137  * Returns the version to be used for SMCCCv1.1 or later.
138  *
139  * When SMCCCv1.1 or above is not present, returns SMCCCv1.0, but this
140  * does not imply the presence of firmware or a valid conduit. Caller
141  * handling SMCCCv1.0 must determine the conduit by other means.
142  */
143 u32 arm_smccc_get_version(void);
144 
145 void __init arm_smccc_version_init(u32 version, enum arm_smccc_conduit conduit);
146 
147 /**
148  * struct arm_smccc_res - Result from SMC/HVC call
149  * @a0-a3 result values from registers 0 to 3
150  */
151 struct arm_smccc_res {
152 	unsigned long a0;
153 	unsigned long a1;
154 	unsigned long a2;
155 	unsigned long a3;
156 };
157 
158 /**
159  * struct arm_smccc_quirk - Contains quirk information
160  * @id: quirk identification
161  * @state: quirk specific information
162  * @a6: Qualcomm quirk entry for returning post-smc call contents of a6
163  */
164 struct arm_smccc_quirk {
165 	int	id;
166 	union {
167 		unsigned long a6;
168 	} state;
169 };
170 
171 /**
172  * __arm_smccc_smc() - make SMC calls
173  * @a0-a7: arguments passed in registers 0 to 7
174  * @res: result values from registers 0 to 3
175  * @quirk: points to an arm_smccc_quirk, or NULL when no quirks are required.
176  *
177  * This function is used to make SMC calls following SMC Calling Convention.
178  * The content of the supplied param are copied to registers 0 to 7 prior
179  * to the SMC instruction. The return values are updated with the content
180  * from register 0 to 3 on return from the SMC instruction.  An optional
181  * quirk structure provides vendor specific behavior.
182  */
183 asmlinkage void __arm_smccc_smc(unsigned long a0, unsigned long a1,
184 			unsigned long a2, unsigned long a3, unsigned long a4,
185 			unsigned long a5, unsigned long a6, unsigned long a7,
186 			struct arm_smccc_res *res, struct arm_smccc_quirk *quirk);
187 
188 /**
189  * __arm_smccc_hvc() - make HVC calls
190  * @a0-a7: arguments passed in registers 0 to 7
191  * @res: result values from registers 0 to 3
192  * @quirk: points to an arm_smccc_quirk, or NULL when no quirks are required.
193  *
194  * This function is used to make HVC calls following SMC Calling
195  * Convention.  The content of the supplied param are copied to registers 0
196  * to 7 prior to the HVC instruction. The return values are updated with
197  * the content from register 0 to 3 on return from the HVC instruction.  An
198  * optional quirk structure provides vendor specific behavior.
199  */
200 asmlinkage void __arm_smccc_hvc(unsigned long a0, unsigned long a1,
201 			unsigned long a2, unsigned long a3, unsigned long a4,
202 			unsigned long a5, unsigned long a6, unsigned long a7,
203 			struct arm_smccc_res *res, struct arm_smccc_quirk *quirk);
204 
205 #define arm_smccc_smc(...) __arm_smccc_smc(__VA_ARGS__, NULL)
206 
207 #define arm_smccc_smc_quirk(...) __arm_smccc_smc(__VA_ARGS__)
208 
209 #define arm_smccc_hvc(...) __arm_smccc_hvc(__VA_ARGS__, NULL)
210 
211 #define arm_smccc_hvc_quirk(...) __arm_smccc_hvc(__VA_ARGS__)
212 
213 /* SMCCC v1.1 implementation madness follows */
214 #ifdef CONFIG_ARM64
215 
216 #define SMCCC_SMC_INST	"smc	#0"
217 #define SMCCC_HVC_INST	"hvc	#0"
218 
219 #elif defined(CONFIG_ARM)
220 #include <asm/opcodes-sec.h>
221 #include <asm/opcodes-virt.h>
222 
223 #define SMCCC_SMC_INST	__SMC(0)
224 #define SMCCC_HVC_INST	__HVC(0)
225 
226 #endif
227 
228 #define ___count_args(_0, _1, _2, _3, _4, _5, _6, _7, _8, x, ...) x
229 
230 #define __count_args(...)						\
231 	___count_args(__VA_ARGS__, 7, 6, 5, 4, 3, 2, 1, 0)
232 
233 #define __constraint_read_0	"r" (arg0)
234 #define __constraint_read_1	__constraint_read_0, "r" (arg1)
235 #define __constraint_read_2	__constraint_read_1, "r" (arg2)
236 #define __constraint_read_3	__constraint_read_2, "r" (arg3)
237 #define __constraint_read_4	__constraint_read_3, "r" (arg4)
238 #define __constraint_read_5	__constraint_read_4, "r" (arg5)
239 #define __constraint_read_6	__constraint_read_5, "r" (arg6)
240 #define __constraint_read_7	__constraint_read_6, "r" (arg7)
241 
242 #define __declare_arg_0(a0, res)					\
243 	struct arm_smccc_res   *___res = res;				\
244 	register unsigned long arg0 asm("r0") = (u32)a0
245 
246 #define __declare_arg_1(a0, a1, res)					\
247 	typeof(a1) __a1 = a1;						\
248 	struct arm_smccc_res   *___res = res;				\
249 	register unsigned long arg0 asm("r0") = (u32)a0;			\
250 	register typeof(a1) arg1 asm("r1") = __a1
251 
252 #define __declare_arg_2(a0, a1, a2, res)				\
253 	typeof(a1) __a1 = a1;						\
254 	typeof(a2) __a2 = a2;						\
255 	struct arm_smccc_res   *___res = res;				\
256 	register unsigned long arg0 asm("r0") = (u32)a0;			\
257 	register typeof(a1) arg1 asm("r1") = __a1;			\
258 	register typeof(a2) arg2 asm("r2") = __a2
259 
260 #define __declare_arg_3(a0, a1, a2, a3, res)				\
261 	typeof(a1) __a1 = a1;						\
262 	typeof(a2) __a2 = a2;						\
263 	typeof(a3) __a3 = a3;						\
264 	struct arm_smccc_res   *___res = res;				\
265 	register unsigned long arg0 asm("r0") = (u32)a0;			\
266 	register typeof(a1) arg1 asm("r1") = __a1;			\
267 	register typeof(a2) arg2 asm("r2") = __a2;			\
268 	register typeof(a3) arg3 asm("r3") = __a3
269 
270 #define __declare_arg_4(a0, a1, a2, a3, a4, res)			\
271 	typeof(a4) __a4 = a4;						\
272 	__declare_arg_3(a0, a1, a2, a3, res);				\
273 	register typeof(a4) arg4 asm("r4") = __a4
274 
275 #define __declare_arg_5(a0, a1, a2, a3, a4, a5, res)			\
276 	typeof(a5) __a5 = a5;						\
277 	__declare_arg_4(a0, a1, a2, a3, a4, res);			\
278 	register typeof(a5) arg5 asm("r5") = __a5
279 
280 #define __declare_arg_6(a0, a1, a2, a3, a4, a5, a6, res)		\
281 	typeof(a6) __a6 = a6;						\
282 	__declare_arg_5(a0, a1, a2, a3, a4, a5, res);			\
283 	register typeof(a6) arg6 asm("r6") = __a6
284 
285 #define __declare_arg_7(a0, a1, a2, a3, a4, a5, a6, a7, res)		\
286 	typeof(a7) __a7 = a7;						\
287 	__declare_arg_6(a0, a1, a2, a3, a4, a5, a6, res);		\
288 	register typeof(a7) arg7 asm("r7") = __a7
289 
290 #define ___declare_args(count, ...) __declare_arg_ ## count(__VA_ARGS__)
291 #define __declare_args(count, ...)  ___declare_args(count, __VA_ARGS__)
292 
293 #define ___constraints(count)						\
294 	: __constraint_read_ ## count					\
295 	: "memory"
296 #define __constraints(count)	___constraints(count)
297 
298 /*
299  * We have an output list that is not necessarily used, and GCC feels
300  * entitled to optimise the whole sequence away. "volatile" is what
301  * makes it stick.
302  */
303 #define __arm_smccc_1_1(inst, ...)					\
304 	do {								\
305 		register unsigned long r0 asm("r0");			\
306 		register unsigned long r1 asm("r1");			\
307 		register unsigned long r2 asm("r2");			\
308 		register unsigned long r3 asm("r3"); 			\
309 		__declare_args(__count_args(__VA_ARGS__), __VA_ARGS__);	\
310 		asm volatile(inst "\n" :				\
311 			     "=r" (r0), "=r" (r1), "=r" (r2), "=r" (r3)	\
312 			     __constraints(__count_args(__VA_ARGS__)));	\
313 		if (___res)						\
314 			*___res = (typeof(*___res)){r0, r1, r2, r3};	\
315 	} while (0)
316 
317 /*
318  * arm_smccc_1_1_smc() - make an SMCCC v1.1 compliant SMC call
319  *
320  * This is a variadic macro taking one to eight source arguments, and
321  * an optional return structure.
322  *
323  * @a0-a7: arguments passed in registers 0 to 7
324  * @res: result values from registers 0 to 3
325  *
326  * This macro is used to make SMC calls following SMC Calling Convention v1.1.
327  * The content of the supplied param are copied to registers 0 to 7 prior
328  * to the SMC instruction. The return values are updated with the content
329  * from register 0 to 3 on return from the SMC instruction if not NULL.
330  */
331 #define arm_smccc_1_1_smc(...)	__arm_smccc_1_1(SMCCC_SMC_INST, __VA_ARGS__)
332 
333 /*
334  * arm_smccc_1_1_hvc() - make an SMCCC v1.1 compliant HVC call
335  *
336  * This is a variadic macro taking one to eight source arguments, and
337  * an optional return structure.
338  *
339  * @a0-a7: arguments passed in registers 0 to 7
340  * @res: result values from registers 0 to 3
341  *
342  * This macro is used to make HVC calls following SMC Calling Convention v1.1.
343  * The content of the supplied param are copied to registers 0 to 7 prior
344  * to the HVC instruction. The return values are updated with the content
345  * from register 0 to 3 on return from the HVC instruction if not NULL.
346  */
347 #define arm_smccc_1_1_hvc(...)	__arm_smccc_1_1(SMCCC_HVC_INST, __VA_ARGS__)
348 
349 /*
350  * Like arm_smccc_1_1* but always returns SMCCC_RET_NOT_SUPPORTED.
351  * Used when the SMCCC conduit is not defined. The empty asm statement
352  * avoids compiler warnings about unused variables.
353  */
354 #define __fail_smccc_1_1(...)						\
355 	do {								\
356 		__declare_args(__count_args(__VA_ARGS__), __VA_ARGS__);	\
357 		asm ("" : __constraints(__count_args(__VA_ARGS__)));	\
358 		if (___res)						\
359 			___res->a0 = SMCCC_RET_NOT_SUPPORTED;		\
360 	} while (0)
361 
362 /*
363  * arm_smccc_1_1_invoke() - make an SMCCC v1.1 compliant call
364  *
365  * This is a variadic macro taking one to eight source arguments, and
366  * an optional return structure.
367  *
368  * @a0-a7: arguments passed in registers 0 to 7
369  * @res: result values from registers 0 to 3
370  *
371  * This macro will make either an HVC call or an SMC call depending on the
372  * current SMCCC conduit. If no valid conduit is available then -1
373  * (SMCCC_RET_NOT_SUPPORTED) is returned in @res.a0 (if supplied).
374  *
375  * The return value also provides the conduit that was used.
376  */
377 #define arm_smccc_1_1_invoke(...) ({					\
378 		int method = arm_smccc_1_1_get_conduit();		\
379 		switch (method) {					\
380 		case SMCCC_CONDUIT_HVC:					\
381 			arm_smccc_1_1_hvc(__VA_ARGS__);			\
382 			break;						\
383 		case SMCCC_CONDUIT_SMC:					\
384 			arm_smccc_1_1_smc(__VA_ARGS__);			\
385 			break;						\
386 		default:						\
387 			__fail_smccc_1_1(__VA_ARGS__);			\
388 			method = SMCCC_CONDUIT_NONE;			\
389 			break;						\
390 		}							\
391 		method;							\
392 	})
393 
394 #endif /*__ASSEMBLY__*/
395 #endif /*__LINUX_ARM_SMCCC_H*/
396