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+/* SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause) */
+#ifndef _ASM_X86_SGX_H
+#define _ASM_X86_SGX_H
+
+#include <asm/asm.h>
+#include <asm/sgx_arch.h>
+
+/**
+ * ENCLS_FAULT_FLAG - flag signifying an ENCLS return code is a trapnr
+ *
+ * ENCLS has its own (positive value) error codes and also generates
+ * ENCLS specific #GP and #PF faults. And the ENCLS values get munged
+ * with system error codes as everything percolates back up the stack.
+ * Unfortunately (for us), we need to precisely identify each unique
+ * error code, e.g. the action taken if EWB fails varies based on the
+ * type of fault and on the exact SGX error code, i.e. we can't simply
+ * convert all faults to -EFAULT.
+ *
+ * To make all three error types coexist, we set bit 30 to identify an
+ * ENCLS fault. Bit 31 (technically bits N:31) is used to differentiate
+ * between positive (faults and SGX error codes) and negative (system
+ * error codes) values.
+ */
+#define ENCLS_FAULT_FLAG 0x40000000
+
+/**
+ * Check for a fault by looking for a postive value with the fault
+ * flag set. The postive value check is needed to filter out system
+ * error codes since negative values will have all higher order bits
+ * set, including ENCLS_FAULT_FLAG.
+ */
+#define IS_ENCLS_FAULT(r) ((int)(r) > 0 && ((r) & ENCLS_FAULT_FLAG))
+
+/**
+ * Retrieve the encoded trapnr from the specified return code.
+ */
+#define ENCLS_TRAPNR(r) ((r) & ~ENCLS_FAULT_FLAG)
+
+/**
+ * encls_to_err - translate an ENCLS fault or SGX code into a system error code
+ * @ret: positive value return code
+ *
+ * Translate a postive return code, e.g. from ENCLS, into a system error
+ * code. Primarily used by functions that cannot return a non-negative
+ * error code, e.g. kernel callbacks.
+ *
+ * Return:
+ * 0 on success,
+ * -errno on failure
+ */
+static inline int encls_to_err(int ret)
+{
+ if (IS_ENCLS_FAULT(ret))
+ return -EFAULT;
+
+ switch (ret) {
+ case SGX_UNMASKED_EVENT:
+ return -EINTR;
+ case SGX_INVALID_SIG_STRUCT:
+ case SGX_INVALID_ATTRIBUTE:
+ case SGX_INVALID_MEASUREMENT:
+ case SGX_INVALID_EINITTOKEN:
+ case SGX_INVALID_CPUSVN:
+ case SGX_INVALID_ISVSVN:
+ case SGX_INVALID_KEYNAME:
+ return -EINVAL;
+ case SGX_ENCLAVE_ACT:
+ case SGX_CHILD_PRESENT:
+ case SGX_ENTRYEPOCH_LOCKED:
+ case SGX_PREV_TRK_INCMPL:
+ case SGX_PAGE_NOT_MODIFIABLE:
+ case SGX_PAGE_NOT_DEBUGGABLE:
+ return -EBUSY;
+ default:
+ return -EIO;
+ };
+}
+
+/**
+ * __encls_ret_N - encode an ENCLS leaf that returns an error code in EAX
+ * @rax: leaf number
+ * @inputs: asm inputs for the leaf
+ *
+ * Emit assembly for an ENCLS leaf that returns an error code, e.g. EREMOVE.
+ * And because SGX isn't complex enough as it is, leafs 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" \
+ ".section .fixup,\"ax\"\n" \
+ "3: orl $"__stringify(ENCLS_FAULT_FLAG)",%%eax\n" \
+ " jmp 2b\n" \
+ ".previous\n" \
+ _ASM_EXTABLE_FAULT(1b, 3b) \
+ : "=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 leaf that doesn't return an error code
+ * @rax: leaf number
+ * @rbx_out: optional output variable
+ * @inputs: asm inputs for the leaf
+ *
+ * Emit assembly for an ENCLS leaf 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 the requested value in RBX.
+ *
+ * Return:
+ * 0 on success,
+ * trapnr with 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" \
+ ".section .fixup,\"ax\"\n" \
+ "3: orl $"__stringify(ENCLS_FAULT_FLAG)",%%eax\n" \
+ " jmp 2b\n" \
+ ".previous\n" \
+ _ASM_EXTABLE_FAULT(1b, 3b) \
+ : "=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; \
+ })
+
+static inline int __ecreate(struct sgx_pageinfo *pginfo, void *secs)
+{
+ return __encls_2(SGX_ECREATE, pginfo, secs);
+}
+
+static inline int __eextend(void *secs, void *addr)
+{
+ return __encls_2(SGX_EEXTEND, secs, addr);
+}
+
+static inline int __eadd(struct sgx_pageinfo *pginfo, void *addr)
+{
+ return __encls_2(SGX_EADD, pginfo, addr);
+}
+
+static inline int __einit(void *sigstruct, struct sgx_einittoken *einittoken,
+ void *secs)
+{
+ return __encls_ret_3(SGX_EINIT, sigstruct, secs, einittoken);
+}
+
+static inline int __eremove(void *addr)
+{
+ return __encls_ret_1(SGX_EREMOVE, addr);
+}
+
+static inline int __edbgwr(void *addr, unsigned long *data)
+{
+ return __encls_2(SGX_EDGBWR, *data, addr);
+}
+
+static inline int __edbgrd(void *addr, unsigned long *data)
+{
+ return __encls_1_1(SGX_EDGBRD, *data, addr);
+}
+
+static inline int __etrack(void *addr)
+{
+ return __encls_ret_1(SGX_ETRACK, addr);
+}
+
+static inline int __eldu(struct sgx_pageinfo *pginfo, void *addr,
+ void *va)
+{
+ return __encls_ret_3(SGX_ELDU, pginfo, addr, va);
+}
+
+static inline int __eblock(void *addr)
+{
+ return __encls_ret_1(SGX_EBLOCK, addr);
+}
+
+static inline int __epa(void *addr)
+{
+ unsigned long rbx = SGX_PAGE_TYPE_VA;
+
+ return __encls_2(SGX_EPA, rbx, addr);
+}
+
+static inline int __ewb(struct sgx_pageinfo *pginfo, void *addr,
+ void *va)
+{
+ return __encls_ret_3(SGX_EWB, pginfo, addr, va);
+}
+
+static inline int __eaug(struct sgx_pageinfo *pginfo, void *addr)
+{
+ return __encls_2(SGX_EAUG, pginfo, addr);
+}
+
+static inline int __emodpr(struct sgx_secinfo *secinfo, void *addr)
+{
+ return __encls_ret_2(SGX_EMODPR, secinfo, addr);
+}
+
+static inline int __emodt(struct sgx_secinfo *secinfo, void *addr)
+{
+ return __encls_ret_2(SGX_EMODT, secinfo, addr);
+}
+
+#endif /* _ASM_X86_SGX_H */