1// SPDX-License-Identifier: GPL-2.0-only
2
3#include "error.h"
4#include "misc.h"
5#include "tdx.h"
6#include "sev.h"
7#include <asm/shared/tdx.h>
8
9/*
10 * accept_memory() and process_unaccepted_memory() called from EFI stub which
11 * runs before decompressor and its early_tdx_detect().
12 *
13 * Enumerate TDX directly from the early users.
14 */
15static bool early_is_tdx_guest(void)
16{
17	static bool once;
18	static bool is_tdx;
19
20	if (!IS_ENABLED(CONFIG_INTEL_TDX_GUEST))
21		return false;
22
23	if (!once) {
24		u32 eax, sig[3];
25
26		cpuid_count(TDX_CPUID_LEAF_ID, 0, &eax,
27			    &sig[0], &sig[2],  &sig[1]);
28		is_tdx = !memcmp(TDX_IDENT, sig, sizeof(sig));
29		once = true;
30	}
31
32	return is_tdx;
33}
34
35void arch_accept_memory(phys_addr_t start, phys_addr_t end)
36{
37	/* Platform-specific memory-acceptance call goes here */
38	if (early_is_tdx_guest()) {
39		if (!tdx_accept_memory(start, end))
40			panic("TDX: Failed to accept memory\n");
41	} else if (sev_snp_enabled()) {
42		snp_accept_memory(start, end);
43	} else {
44		error("Cannot accept memory: unknown platform\n");
45	}
46}
47
48bool init_unaccepted_memory(void)
49{
50	guid_t guid = LINUX_EFI_UNACCEPTED_MEM_TABLE_GUID;
51	struct efi_unaccepted_memory *table;
52	unsigned long cfg_table_pa;
53	unsigned int cfg_table_len;
54	enum efi_type et;
55	int ret;
56
57	et = efi_get_type(boot_params_ptr);
58	if (et == EFI_TYPE_NONE)
59		return false;
60
61	ret = efi_get_conf_table(boot_params_ptr, &cfg_table_pa, &cfg_table_len);
62	if (ret) {
63		warn("EFI config table not found.");
64		return false;
65	}
66
67	table = (void *)efi_find_vendor_table(boot_params_ptr, cfg_table_pa,
68					      cfg_table_len, guid);
69	if (!table)
70		return false;
71
72	if (table->version != 1)
73		error("Unknown version of unaccepted memory table\n");
74
75	/*
76	 * In many cases unaccepted_table is already set by EFI stub, but it
77	 * has to be initialized again to cover cases when the table is not
78	 * allocated by EFI stub or EFI stub copied the kernel image with
79	 * efi_relocate_kernel() before the variable is set.
80	 *
81	 * It must be initialized before the first usage of accept_memory().
82	 */
83	unaccepted_table = table;
84
85	return true;
86}
87