1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _X86_ENCLS_H
3 #define _X86_ENCLS_H
4 
5 #include <linux/bitops.h>
6 #include <linux/err.h>
7 #include <linux/io.h>
8 #include <linux/rwsem.h>
9 #include <linux/types.h>
10 #include <asm/asm.h>
11 #include <asm/traps.h>
12 #include "sgx.h"
13 
14 /* Retrieve the encoded trapnr from the specified return code. */
15 #define ENCLS_TRAPNR(r) ((r) & ~SGX_ENCLS_FAULT_FLAG)
16 
17 /* Issue a WARN() about an ENCLS function. */
18 #define ENCLS_WARN(r, name) {						  \
19 	do {								  \
20 		int _r = (r);						  \
21 		WARN_ONCE(_r, "%s returned %d (0x%x)\n", (name), _r, _r); \
22 	} while (0);							  \
23 }
24 
25 /*
26  * encls_faulted() - Check if an ENCLS leaf faulted given an error code
27  * @ret:	the return value of an ENCLS leaf function call
28  *
29  * Return:
30  * - true:	ENCLS leaf faulted.
31  * - false:	Otherwise.
32  */
encls_faulted(int ret)33 static inline bool encls_faulted(int ret)
34 {
35 	return ret & SGX_ENCLS_FAULT_FLAG;
36 }
37 
38 /**
39  * encls_failed() - Check if an ENCLS function failed
40  * @ret:	the return value of an ENCLS function call
41  *
42  * Check if an ENCLS function failed. This happens when the function causes a
43  * fault that is not caused by an EPCM conflict or when the function returns a
44  * non-zero value.
45  */
encls_failed(int ret)46 static inline bool encls_failed(int ret)
47 {
48 	if (encls_faulted(ret))
49 		return ENCLS_TRAPNR(ret) != X86_TRAP_PF;
50 
51 	return !!ret;
52 }
53 
54 /**
55  * __encls_ret_N - encode an ENCLS function that returns an error code in EAX
56  * @rax:	function number
57  * @inputs:	asm inputs for the function
58  *
59  * Emit assembly for an ENCLS function that returns an error code, e.g. EREMOVE.
60  * And because SGX isn't complex enough as it is, function that return an error
61  * code also modify flags.
62  *
63  * Return:
64  *	0 on success,
65  *	SGX error code on failure
66  */
67 #define __encls_ret_N(rax, inputs...)				\
68 	({							\
69 	int ret;						\
70 	asm volatile(						\
71 	"1: .byte 0x0f, 0x01, 0xcf;\n\t"			\
72 	"2:\n"							\
73 	_ASM_EXTABLE_TYPE(1b, 2b, EX_TYPE_FAULT_SGX)		\
74 	: "=a"(ret)						\
75 	: "a"(rax), inputs					\
76 	: "memory", "cc");					\
77 	ret;							\
78 	})
79 
80 #define __encls_ret_1(rax, rcx)		\
81 	({				\
82 	__encls_ret_N(rax, "c"(rcx));	\
83 	})
84 
85 #define __encls_ret_2(rax, rbx, rcx)		\
86 	({					\
87 	__encls_ret_N(rax, "b"(rbx), "c"(rcx));	\
88 	})
89 
90 #define __encls_ret_3(rax, rbx, rcx, rdx)			\
91 	({							\
92 	__encls_ret_N(rax, "b"(rbx), "c"(rcx), "d"(rdx));	\
93 	})
94 
95 /**
96  * __encls_N - encode an ENCLS function that doesn't return an error code
97  * @rax:	function number
98  * @rbx_out:	optional output variable
99  * @inputs:	asm inputs for the function
100  *
101  * Emit assembly for an ENCLS function that does not return an error code, e.g.
102  * ECREATE.  Leaves without error codes either succeed or fault.  @rbx_out is an
103  * optional parameter for use by EDGBRD, which returns the requested value in
104  * RBX.
105  *
106  * Return:
107  *   0 on success,
108  *   trapnr with SGX_ENCLS_FAULT_FLAG set on fault
109  */
110 #define __encls_N(rax, rbx_out, inputs...)			\
111 	({							\
112 	int ret;						\
113 	asm volatile(						\
114 	"1: .byte 0x0f, 0x01, 0xcf;\n\t"			\
115 	"   xor %%eax,%%eax;\n"					\
116 	"2:\n"							\
117 	_ASM_EXTABLE_TYPE(1b, 2b, EX_TYPE_FAULT_SGX)		\
118 	: "=a"(ret), "=b"(rbx_out)				\
119 	: "a"(rax), inputs					\
120 	: "memory");						\
121 	ret;							\
122 	})
123 
124 #define __encls_2(rax, rbx, rcx)				\
125 	({							\
126 	unsigned long ign_rbx_out;				\
127 	__encls_N(rax, ign_rbx_out, "b"(rbx), "c"(rcx));	\
128 	})
129 
130 #define __encls_1_1(rax, data, rcx)			\
131 	({						\
132 	unsigned long rbx_out;				\
133 	int ret = __encls_N(rax, rbx_out, "c"(rcx));	\
134 	if (!ret)					\
135 		data = rbx_out;				\
136 	ret;						\
137 	})
138 
139 /* Initialize an EPC page into an SGX Enclave Control Structure (SECS) page. */
__ecreate(struct sgx_pageinfo * pginfo,void * secs)140 static inline int __ecreate(struct sgx_pageinfo *pginfo, void *secs)
141 {
142 	return __encls_2(ECREATE, pginfo, secs);
143 }
144 
145 /* Hash a 256 byte region of an enclave page to SECS:MRENCLAVE. */
__eextend(void * secs,void * addr)146 static inline int __eextend(void *secs, void *addr)
147 {
148 	return __encls_2(EEXTEND, secs, addr);
149 }
150 
151 /*
152  * Associate an EPC page to an enclave either as a REG or TCS page
153  * populated with the provided data.
154  */
__eadd(struct sgx_pageinfo * pginfo,void * addr)155 static inline int __eadd(struct sgx_pageinfo *pginfo, void *addr)
156 {
157 	return __encls_2(EADD, pginfo, addr);
158 }
159 
160 /* Finalize enclave build, initialize enclave for user code execution. */
__einit(void * sigstruct,void * token,void * secs)161 static inline int __einit(void *sigstruct, void *token, void *secs)
162 {
163 	return __encls_ret_3(EINIT, sigstruct, secs, token);
164 }
165 
166 /* Disassociate EPC page from its enclave and mark it as unused. */
__eremove(void * addr)167 static inline int __eremove(void *addr)
168 {
169 	return __encls_ret_1(EREMOVE, addr);
170 }
171 
172 /* Copy data to an EPC page belonging to a debug enclave. */
__edbgwr(void * addr,unsigned long * data)173 static inline int __edbgwr(void *addr, unsigned long *data)
174 {
175 	return __encls_2(EDGBWR, *data, addr);
176 }
177 
178 /* Copy data from an EPC page belonging to a debug enclave. */
__edbgrd(void * addr,unsigned long * data)179 static inline int __edbgrd(void *addr, unsigned long *data)
180 {
181 	return __encls_1_1(EDGBRD, *data, addr);
182 }
183 
184 /* Track that software has completed the required TLB address clears. */
__etrack(void * addr)185 static inline int __etrack(void *addr)
186 {
187 	return __encls_ret_1(ETRACK, addr);
188 }
189 
190 /* Load, verify, and unblock an EPC page. */
__eldu(struct sgx_pageinfo * pginfo,void * addr,void * va)191 static inline int __eldu(struct sgx_pageinfo *pginfo, void *addr,
192 			 void *va)
193 {
194 	return __encls_ret_3(ELDU, pginfo, addr, va);
195 }
196 
197 /* Make EPC page inaccessible to enclave, ready to be written to memory. */
__eblock(void * addr)198 static inline int __eblock(void *addr)
199 {
200 	return __encls_ret_1(EBLOCK, addr);
201 }
202 
203 /* Initialize an EPC page into a Version Array (VA) page. */
__epa(void * addr)204 static inline int __epa(void *addr)
205 {
206 	unsigned long rbx = SGX_PAGE_TYPE_VA;
207 
208 	return __encls_2(EPA, rbx, addr);
209 }
210 
211 /* Invalidate an EPC page and write it out to main memory. */
__ewb(struct sgx_pageinfo * pginfo,void * addr,void * va)212 static inline int __ewb(struct sgx_pageinfo *pginfo, void *addr,
213 			void *va)
214 {
215 	return __encls_ret_3(EWB, pginfo, addr, va);
216 }
217 
218 /* Restrict the EPCM permissions of an EPC page. */
__emodpr(struct sgx_secinfo * secinfo,void * addr)219 static inline int __emodpr(struct sgx_secinfo *secinfo, void *addr)
220 {
221 	return __encls_ret_2(EMODPR, secinfo, addr);
222 }
223 
224 /* Change the type of an EPC page. */
__emodt(struct sgx_secinfo * secinfo,void * addr)225 static inline int __emodt(struct sgx_secinfo *secinfo, void *addr)
226 {
227 	return __encls_ret_2(EMODT, secinfo, addr);
228 }
229 
230 /* Zero a page of EPC memory and add it to an initialized enclave. */
__eaug(struct sgx_pageinfo * pginfo,void * addr)231 static inline int __eaug(struct sgx_pageinfo *pginfo, void *addr)
232 {
233 	return __encls_2(EAUG, pginfo, addr);
234 }
235 
236 #endif /* _X86_ENCLS_H */
237