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 */
14 void __tdx_hypercall_failed(void)
15 {
16 error("TDVMCALL failed. TDX module bug?");
17 }
18
19 static inline unsigned int tdx_io_in(int size, u16 port)
20 {
21 struct tdx_module_args args = {
22 .r10 = TDX_HYPERCALL_STANDARD,
23 .r11 = hcall_func(EXIT_REASON_IO_INSTRUCTION),
24 .r12 = size,
25 .r13 = 0,
26 .r14 = port,
27 };
28
29 if (__tdx_hypercall(&args))
30 return UINT_MAX;
31
32 return args.r11;
33 }
34
35 static inline void tdx_io_out(int size, u16 port, u32 value)
36 {
37 struct tdx_module_args args = {
38 .r10 = TDX_HYPERCALL_STANDARD,
39 .r11 = hcall_func(EXIT_REASON_IO_INSTRUCTION),
40 .r12 = size,
41 .r13 = 1,
42 .r14 = port,
43 .r15 = value,
44 };
45
46 __tdx_hypercall(&args);
47 }
48
49 static inline u8 tdx_inb(u16 port)
50 {
51 return tdx_io_in(1, port);
52 }
53
54 static inline void tdx_outb(u8 value, u16 port)
55 {
56 tdx_io_out(1, port, value);
57 }
58
59 static inline void tdx_outw(u16 value, u16 port)
60 {
61 tdx_io_out(2, port, value);
62 }
63
64 void 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 }
78
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