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/* 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"
/**
* 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
/* Retrieve the encoded trapnr from the specified return code. */
#define ENCLS_TRAPNR(r) ((r) & ~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 & 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" \
".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 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 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(ECREATE, pginfo, secs);
}
static inline int __eextend(void *secs, void *addr)
{
return __encls_2(EEXTEND, secs, addr);
}
static inline int __eadd(struct sgx_pageinfo *pginfo, void *addr)
{
return __encls_2(EADD, pginfo, addr);
}
static inline int __einit(void *sigstruct, void *token, void *secs)
{
return __encls_ret_3(EINIT, sigstruct, secs, token);
}
static inline int __eremove(void *addr)
{
return __encls_ret_1(EREMOVE, addr);
}
static inline int __edbgwr(void *addr, unsigned long *data)
{
return __encls_2(EDGBWR, *data, addr);
}
static inline int __edbgrd(void *addr, unsigned long *data)
{
return __encls_1_1(EDGBRD, *data, addr);
}
static inline int __etrack(void *addr)
{
return __encls_ret_1(ETRACK, addr);
}
static inline int __eldu(struct sgx_pageinfo *pginfo, void *addr,
void *va)
{
return __encls_ret_3(ELDU, pginfo, addr, va);
}
static inline int __eblock(void *addr)
{
return __encls_ret_1(EBLOCK, addr);
}
static inline int __epa(void *addr)
{
unsigned long rbx = SGX_PAGE_TYPE_VA;
return __encls_2(EPA, rbx, addr);
}
static inline int __ewb(struct sgx_pageinfo *pginfo, void *addr,
void *va)
{
return __encls_ret_3(EWB, pginfo, addr, va);
}
#endif /* _X86_ENCLS_H */
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