1 files changed, 236 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/sgx/encls.h b/arch/x86/kernel/cpu/sgx/encls.h
new file mode 100644
index 000000000..99004b02e
--- /dev/null
+++ b/arch/x86/kernel/cpu/sgx/encls.h
@@ -0,0 +1,236 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _X86_ENCLS_H
+#define _X86_ENCLS_H
+
+#include <linux/bitops.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/rwsem.h>
+#include <linux/types.h>
+#include <asm/asm.h>
+#include <asm/traps.h>
+#include "sgx.h"
+
+/* Retrieve the encoded trapnr from the specified return code. */
+#define ENCLS_TRAPNR(r) ((r) & ~SGX_ENCLS_FAULT_FLAG)
+
+/* Issue a WARN() about an ENCLS function. */
+#define ENCLS_WARN(r, name) {						  \
+	do {								  \
+		int _r = (r);						  \
+		WARN_ONCE(_r, "%s returned %d (0x%x)\n", (name), _r, _r); \
+	} while (0);							  \
+}
+
+/*
+ * encls_faulted() - Check if an ENCLS leaf faulted given an error code
+ * @ret:	the return value of an ENCLS leaf function call
+ *
+ * Return:
+ * - true:	ENCLS leaf faulted.
+ * - false:	Otherwise.
+ */
+static inline bool encls_faulted(int ret)
+{
+	return ret & SGX_ENCLS_FAULT_FLAG;
+}
+
+/**
+ * encls_failed() - Check if an ENCLS function failed
+ * @ret:	the return value of an ENCLS function call
+ *
+ * Check if an ENCLS function failed. This happens when the function causes a
+ * fault that is not caused by an EPCM conflict or when the function returns a
+ * non-zero value.
+ */
+static inline bool encls_failed(int ret)
+{
+	if (encls_faulted(ret))
+		return ENCLS_TRAPNR(ret) != X86_TRAP_PF;
+
+	return !!ret;
+}
+
+/**
+ * __encls_ret_N - encode an ENCLS function that returns an error code in EAX
+ * @rax:	function number
+ * @inputs:	asm inputs for the function
+ *
+ * Emit assembly for an ENCLS function that returns an error code, e.g. EREMOVE.
+ * And because SGX isn't complex enough as it is, function that return an error
+ * code also modify flags.
+ *
+ * Return:
+ *	0 on success,
+ *	SGX error code on failure
+ */
+#define __encls_ret_N(rax, inputs...)				\
+	({							\
+	int ret;						\
+	asm volatile(						\
+	"1: .byte 0x0f, 0x01, 0xcf;\n\t"			\
+	"2:\n"							\
+	_ASM_EXTABLE_TYPE(1b, 2b, EX_TYPE_FAULT_SGX)		\
+	: "=a"(ret)						\
+	: "a"(rax), inputs					\
+	: "memory", "cc");					\
+	ret;							\
+	})
+
+#define __encls_ret_1(rax, rcx)		\
+	({				\
+	__encls_ret_N(rax, "c"(rcx));	\
+	})
+
+#define __encls_ret_2(rax, rbx, rcx)		\
+	({					\
+	__encls_ret_N(rax, "b"(rbx), "c"(rcx));	\
+	})
+
+#define __encls_ret_3(rax, rbx, rcx, rdx)			\
+	({							\
+	__encls_ret_N(rax, "b"(rbx), "c"(rcx), "d"(rdx));	\
+	})
+
+/**
+ * __encls_N - encode an ENCLS function that doesn't return an error code
+ * @rax:	function number
+ * @rbx_out:	optional output variable
+ * @inputs:	asm inputs for the function
+ *
+ * Emit assembly for an ENCLS function that does not return an error code, e.g.
+ * ECREATE.  Leaves without error codes either succeed or fault.  @rbx_out is an
+ * optional parameter for use by EDGBRD, which returns the requested value in
+ * RBX.
+ *
+ * Return:
+ *   0 on success,
+ *   trapnr with SGX_ENCLS_FAULT_FLAG set on fault
+ */
+#define __encls_N(rax, rbx_out, inputs...)			\
+	({							\
+	int ret;						\
+	asm volatile(						\
+	"1: .byte 0x0f, 0x01, 0xcf;\n\t"			\
+	"   xor %%eax,%%eax;\n"					\
+	"2:\n"							\
+	_ASM_EXTABLE_TYPE(1b, 2b, EX_TYPE_FAULT_SGX)		\
+	: "=a"(ret), "=b"(rbx_out)				\
+	: "a"(rax), inputs					\
+	: "memory");						\
+	ret;							\
+	})
+
+#define __encls_2(rax, rbx, rcx)				\
+	({							\
+	unsigned long ign_rbx_out;				\
+	__encls_N(rax, ign_rbx_out, "b"(rbx), "c"(rcx));	\
+	})
+
+#define __encls_1_1(rax, data, rcx)			\
+	({						\
+	unsigned long rbx_out;				\
+	int ret = __encls_N(rax, rbx_out, "c"(rcx));	\
+	if (!ret)					\
+		data = rbx_out;				\
+	ret;						\
+	})
+
+/* Initialize an EPC page into an SGX Enclave Control Structure (SECS) page. */
+static inline int __ecreate(struct sgx_pageinfo *pginfo, void *secs)
+{
+	return __encls_2(ECREATE, pginfo, secs);
+}
+
+/* Hash a 256 byte region of an enclave page to SECS:MRENCLAVE. */
+static inline int __eextend(void *secs, void *addr)
+{
+	return __encls_2(EEXTEND, secs, addr);
+}
+
+/*
+ * Associate an EPC page to an enclave either as a REG or TCS page
+ * populated with the provided data.
+ */
+static inline int __eadd(struct sgx_pageinfo *pginfo, void *addr)
+{
+	return __encls_2(EADD, pginfo, addr);
+}
+
+/* Finalize enclave build, initialize enclave for user code execution. */
+static inline int __einit(void *sigstruct, void *token, void *secs)
+{
+	return __encls_ret_3(EINIT, sigstruct, secs, token);
+}
+
+/* Disassociate EPC page from its enclave and mark it as unused. */
+static inline int __eremove(void *addr)
+{
+	return __encls_ret_1(EREMOVE, addr);
+}
+
+/* Copy data to an EPC page belonging to a debug enclave. */
+static inline int __edbgwr(void *addr, unsigned long *data)
+{
+	return __encls_2(EDGBWR, *data, addr);
+}
+
+/* Copy data from an EPC page belonging to a debug enclave. */
+static inline int __edbgrd(void *addr, unsigned long *data)
+{
+	return __encls_1_1(EDGBRD, *data, addr);
+}
+
+/* Track that software has completed the required TLB address clears. */
+static inline int __etrack(void *addr)
+{
+	return __encls_ret_1(ETRACK, addr);
+}
+
+/* Load, verify, and unblock an EPC page. */
+static inline int __eldu(struct sgx_pageinfo *pginfo, void *addr,
+			 void *va)
+{
+	return __encls_ret_3(ELDU, pginfo, addr, va);
+}
+
+/* Make EPC page inaccessible to enclave, ready to be written to memory. */
+static inline int __eblock(void *addr)
+{
+	return __encls_ret_1(EBLOCK, addr);
+}
+
+/* Initialize an EPC page into a Version Array (VA) page. */
+static inline int __epa(void *addr)
+{
+	unsigned long rbx = SGX_PAGE_TYPE_VA;
+
+	return __encls_2(EPA, rbx, addr);
+}
+
+/* Invalidate an EPC page and write it out to main memory. */
+static inline int __ewb(struct sgx_pageinfo *pginfo, void *addr,
+			void *va)
+{
+	return __encls_ret_3(EWB, pginfo, addr, va);
+}
+
+/* Restrict the EPCM permissions of an EPC page. */
+static inline int __emodpr(struct sgx_secinfo *secinfo, void *addr)
+{
+	return __encls_ret_2(EMODPR, secinfo, addr);
+}
+
+/* Change the type of an EPC page. */
+static inline int __emodt(struct sgx_secinfo *secinfo, void *addr)
+{
+	return __encls_ret_2(EMODT, secinfo, addr);
+}
+
+/* Zero a page of EPC memory and add it to an initialized enclave. */
+static inline int __eaug(struct sgx_pageinfo *pginfo, void *addr)
+{
+	return __encls_2(EAUG, pginfo, addr);
+}
+
+#endif /* _X86_ENCLS_H */