1// SPDX-License-Identifier: GPL-2.0
 2
 3#include "../cpuflags.h"
 4#include "../string.h"
 5#include "../io.h"
 6#include "error.h"
 7
 8#include <vdso/limits.h>
 9#include <uapi/asm/vmx.h>
10
11#include <asm/shared/tdx.h>
12
13/* Called from __tdx_hypercall() for unrecoverable failure */
14void __tdx_hypercall_failed(void)
15{
16	error("TDVMCALL failed. TDX module bug?");
17}
18
19static inline unsigned int tdx_io_in(int size, u16 port)
20{
21	struct tdx_hypercall_args args = {
22		.r10 = TDX_HYPERCALL_STANDARD,
23		.r11 = EXIT_REASON_IO_INSTRUCTION,
24		.r12 = size,
25		.r13 = 0,
26		.r14 = port,
27	};
28
29	if (__tdx_hypercall(&args, TDX_HCALL_HAS_OUTPUT))
30		return UINT_MAX;
31
32	return args.r11;
33}
34
35static inline void tdx_io_out(int size, u16 port, u32 value)
36{
37	struct tdx_hypercall_args args = {
38		.r10 = TDX_HYPERCALL_STANDARD,
39		.r11 = EXIT_REASON_IO_INSTRUCTION,
40		.r12 = size,
41		.r13 = 1,
42		.r14 = port,
43		.r15 = value,
44	};
45
46	__tdx_hypercall(&args, 0);
47}
48
49static inline u8 tdx_inb(u16 port)
50{
51	return tdx_io_in(1, port);
52}
53
54static inline void tdx_outb(u8 value, u16 port)
55{
56	tdx_io_out(1, port, value);
57}
58
59static inline void tdx_outw(u16 value, u16 port)
60{
61	tdx_io_out(2, port, value);
62}
63
64void early_tdx_detect(void)
65{
66	u32 eax, sig[3];
67
68	cpuid_count(TDX_CPUID_LEAF_ID, 0, &eax, &sig[0], &sig[2],  &sig[1]);
69
70	if (memcmp(TDX_IDENT, sig, sizeof(sig)))
71		return;
72
73	/* Use hypercalls instead of I/O instructions */
74	pio_ops.f_inb  = tdx_inb;
75	pio_ops.f_outb = tdx_outb;
76	pio_ops.f_outw = tdx_outw;
77}