Move memory acceptance x86 arch code into EFI stub

index 5ac43762fe13..dc38047647cc 100644
@@ -1,2 +1,4 @@
+#define __NO_FORTIFY
+
 #include "error.h"
 #include "../../coco/tdx/tdx-shared.c"

index 1655aa56a0a5..29661d8dfe8e 100644
@@ -89,3 +89,34 @@ noinstr u64 __tdx_hypercall(struct tdx_module_args *args)
 	/* TDVMCALL leaf return code is in R10 */
 	return args->r10;
 }
+
+void __noreturn tdx_panic(const char *msg)
+{
+	struct tdx_module_args args = {
+		.r10 = TDX_HYPERCALL_STANDARD,
+		.r11 = TDVMCALL_REPORT_FATAL_ERROR,
+		.r12 = 0, /* Error code: 0 is Panic */
+	};
+	/* Define register order according to the GHCI */
+	struct { u64 r14, r15, rbx, rdi, rsi, r8, r9, rdx; } message = {};
+
+	/* VMM assumes '\0' in byte 65, if the message took all 64 bytes */
+	memcpy(&message, msg, strnlen(msg, sizeof(message)));
+
+	args.r8  = message.r8;
+	args.r9  = message.r9;
+	args.r14 = message.r14;
+	args.r15 = message.r15;
+	args.rdi = message.rdi;
+	args.rsi = message.rsi;
+	args.rbx = message.rbx;
+	args.rdx = message.rdx;
+
+	/*
+	 * This hypercall should never return and it is not safe
+	 * to keep the guest running. Call it forever if it
+	 * happens to return.
+	 */
+	while (1)
+		__tdx_hypercall(&args);
+}

index f904a636d449..a9a16d0fb5c2 100644
@@ -198,41 +198,6 @@ u64 tdx_hcall_get_quote(u8 *buf, size_t size)
 }
 EXPORT_SYMBOL_GPL(tdx_hcall_get_quote);
 
-static void __noreturn tdx_panic(const char *msg)
-{
-	struct tdx_module_args args = {
-		.r10 = TDX_HYPERCALL_STANDARD,
-		.r11 = TDVMCALL_REPORT_FATAL_ERROR,
-		.r12 = 0, /* Error code: 0 is Panic */
-	};
-	union {
-		/* Define register order according to the GHCI */
-		struct { u64 r14, r15, rbx, rdi, rsi, r8, r9, rdx; };
-
-		char bytes[64] __nonstring;
-	} message;
-
-	/* VMM assumes '\0' in byte 65, if the message took all 64 bytes */
-	strtomem_pad(message.bytes, msg, '\0');
-
-	args.r8  = message.r8;
-	args.r9  = message.r9;
-	args.r14 = message.r14;
-	args.r15 = message.r15;
-	args.rdi = message.rdi;
-	args.rsi = message.rsi;
-	args.rbx = message.rbx;
-	args.rdx = message.rdx;
-
-	/*
-	 * This hypercall should never return and it is not safe
-	 * to keep the guest running. Call it forever if it
-	 * happens to return.
-	 */
-	while (1)
-		__tdx_hypercall(&args);
-}
-
 /*
  * The kernel cannot handle #VEs when accessing normal kernel memory. Ensure
  * that no #VE will be delivered for accesses to TD-private memory.

index f20e91d7ac35..e5785258e547 100644
@@ -171,6 +171,7 @@ static inline u64 _tdx_hypercall(u64 fn, u64 r12, u64 r13, u64 r14, u64 r15)
 	return __tdx_hypercall(&args);
 }
 
+void __noreturn tdx_panic(const char *msg);
 
 /* Called from __tdx_hypercall() for unrecoverable failure */
 void __noreturn __tdx_hypercall_failed(void);

index 0e9f84ab4bdc..1721af3a8039 100644
@@ -2,48 +2,6 @@
 
 #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)
 {

index 22637b416b46..62e50c2e71ed 100644
@@ -14,7 +14,6 @@
 
 void snp_accept_memory(phys_addr_t start, phys_addr_t end);
 u64 sev_get_status(void);
-bool early_is_sevsnp_guest(void);
 
 static inline u64 sev_es_rd_ghcb_msr(void)
 {

@@ -37,7 +36,6 @@ static inline void sev_es_wr_ghcb_msr(u64 val)
 
 static inline void snp_accept_memory(phys_addr_t start, phys_addr_t end) { }
 static inline u64 sev_get_status(void) { return 0; }
-static inline bool early_is_sevsnp_guest(void) { return false; }
 
 #endif
 

index 9e7a077c445d..4b5db43cc0b1 100644
@@ -517,6 +517,7 @@ void snp_accept_memory(phys_addr_t start, phys_addr_t end);
 u64 snp_get_unsupported_features(u64 status);
 u64 sev_get_status(void);
 void sev_show_status(void);
+bool early_is_sevsnp_guest(void);
 int prepare_pte_enc(struct pte_enc_desc *d);
 void set_pte_enc_mask(pte_t *kpte, unsigned long pfn, pgprot_t new_prot);
 void snp_kexec_finish(void);

@@ -626,6 +627,7 @@ static inline void snp_accept_memory(phys_addr_t start, phys_addr_t end) { }
 static inline u64 snp_get_unsupported_features(u64 status) { return 0; }
 static inline u64 sev_get_status(void) { return 0; }
 static inline void sev_show_status(void) { }
+static inline bool early_is_sevsnp_guest(void) { return false; }
 static inline int prepare_pte_enc(struct pte_enc_desc *d) { return 0; }
 static inline void set_pte_enc_mask(pte_t *kpte, unsigned long pfn, pgprot_t new_prot) { }
 static inline void snp_kexec_finish(void) { }

index cef32e2c82d8..80556a7e7552 100644
@@ -10,6 +10,7 @@
 #include <linux/pci.h>
 #include <linux/stddef.h>
 
+#include <asm/cpuid/api.h>
 #include <asm/efi.h>
 #include <asm/e820/types.h>
 #include <asm/setup.h>

@@ -17,6 +18,7 @@
 #include <asm/boot.h>
 #include <asm/kaslr.h>
 #include <asm/sev.h>
+#include <asm/shared/tdx.h>
 
 #include "efistub.h"
 #include "x86-stub.h"

@@ -1068,3 +1070,40 @@ void efi64_stub_entry(efi_handle_t handle, efi_system_table_t *sys_table_arg,
 		      struct boot_params *boot_params);
 #endif
 #endif
+
+#ifdef CONFIG_UNACCEPTED_MEMORY
+/*
+ * process_unaccepted_memory() is called after ExitBootServices(), and so these
+ * memory acceptance routines cannot rely on EFI protocols for detecting the
+ * presence of TDX or SEV-SNP, or emit any kind of output if any error
+ * conditions are detected.
+ */
+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 = TDX_CPUID_LEAF_ID, sig[3] = {};
+
+		native_cpuid(&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)
+{
+	if (early_is_tdx_guest()) {
+		if (!tdx_accept_memory(start, end))
+			tdx_panic("Failed to accept memory");
+	} else if (early_is_sevsnp_guest()) {
+		snp_accept_memory(start, end);
+	}
+}
+#endif

index 19a8251de506..ce5ed7d8265e 100644
@@ -22,22 +22,3 @@ void error(char *m)
 	while (1)
 		asm("hlt");
 }
-
-/* EFI libstub  provides vsnprintf() */
-#ifdef CONFIG_EFI_STUB
-void panic(const char *fmt, ...)
-{
-	static char buf[1024];
-	va_list args;
-	int len;
-
-	va_start(args, fmt);
-	len = vsnprintf(buf, sizeof(buf), fmt, args);
-	va_end(args);
-
-	if (len && buf[len - 1] == '\n')
-		buf[len - 1] = '\0';
-
-	error(buf);
-}
-#endif

index 31f9e080d61a..87062dea9a20 100644
@@ -6,6 +6,5 @@
 
 void warn(const char *m);
 void error(char *m) __noreturn;
-void panic(const char *fmt, ...) __noreturn __cold;
 
 #endif /* BOOT_COMPRESSED_ERROR_H */