// SPDX-License-Identifier: GPL-2.0-only

#include "error.h"
#include "misc.h"
#include "tdx.h"
#include "sev.h"
#include <asm/shared/tdx.h>

/*
 * accept_memory() and process_unaccepted_memory() called from EFI stub which
 * runs before decompressor and its early_tdx_detect().
 *
 * Enumerate TDX directly from the early users.
 */
static bool early_is_tdx_guest(void)
{
        static bool once;
        static bool is_tdx;

        if (!IS_ENABLED(CONFIG_INTEL_TDX_GUEST))
                return false;

        if (!once) {
                u32 eax, sig[3];

                cpuid_count(TDX_CPUID_LEAF_ID, 0, &eax,
                            &sig[0], &sig[2],  &sig[1]);
                is_tdx = !memcmp(TDX_IDENT, sig, sizeof(sig));
                once = true;
        }

        return is_tdx;
}

void arch_accept_memory(phys_addr_t start, phys_addr_t end)
{
        /* Platform-specific memory-acceptance call goes here */
        if (early_is_tdx_guest()) {
                if (!tdx_accept_memory(start, end))
                        panic("TDX: Failed to accept memory\n");
        } else if (early_is_sevsnp_guest()) {
                snp_accept_memory(start, end);
        } else {
                error("Cannot accept memory: unknown platform\n");
        }
}

bool init_unaccepted_memory(void)
{
        guid_t guid = LINUX_EFI_UNACCEPTED_MEM_TABLE_GUID;
        struct efi_unaccepted_memory *table;
        unsigned long cfg_table_pa;
        unsigned int cfg_table_len;
        enum efi_type et;
        int ret;

        et = efi_get_type(boot_params_ptr);
        if (et == EFI_TYPE_NONE)
                return false;

        ret = efi_get_conf_table(boot_params_ptr, &cfg_table_pa, &cfg_table_len);
        if (ret) {
                warn("EFI config table not found.");
                return false;
        }

        table = (void *)efi_find_vendor_table(boot_params_ptr, cfg_table_pa,
                                              cfg_table_len, guid);
        if (!table)
                return false;

        if (table->version != 1)
                error("Unknown version of unaccepted memory table\n");

        /*
         * In many cases unaccepted_table is already set by EFI stub, but it
         * has to be initialized again to cover cases when the table is not
         * allocated by EFI stub or EFI stub copied the kernel image with
         * efi_relocate_kernel() before the variable is set.
         *
         * It must be initialized before the first usage of accept_memory().
         */
        unaccepted_table = table;

        return true;
}