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From:   Thomas Gleixner <tglx@linutronix.de>
To:     LKML <linux-kernel@vger.kernel.org>
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Subject: [patch 07/37] x86/smpboot: Restrict soft_restart_cpu() to SEV
References: <20230414225551.858160935@linutronix.de>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Date:   Sat, 15 Apr 2023 01:44:24 +0200 (CEST)
Precedence: bulk

Now that the CPU0 hotplug cruft is gone, the only user is AMD SEV.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
---
 arch/x86/kernel/callthunks.c |    2 +-
 arch/x86/kernel/head_32.S    |   14 --------------
 arch/x86/kernel/head_64.S    |    2 +-
 3 files changed, 2 insertions(+), 16 deletions(-)

--- a/arch/x86/kernel/callthunks.c
+++ b/arch/x86/kernel/callthunks.c
@@ -133,7 +133,7 @@ static bool skip_addr(void *dest)
 	/* Accounts directly */
 	if (dest == ret_from_fork)
 		return true;
-#ifdef CONFIG_HOTPLUG_CPU
+#if defined(CONFIG_HOTPLUG_CPU) && defined(CONFIG_AMD_MEM_ENCRYPT)
 	if (dest == soft_restart_cpu)
 		return true;
 #endif
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -138,20 +138,6 @@ SYM_CODE_START(startup_32)
 	jmp .Ldefault_entry
 SYM_CODE_END(startup_32)
 
-#ifdef CONFIG_HOTPLUG_CPU
-/*
- * Entry point for soft restart of a CPU. Invoked from xxx_play_dead() for
- * restarting the boot CPU or for restarting SEV guest CPUs after CPU hot
- * unplug. Everything is set up already except the stack.
- */
-SYM_FUNC_START(soft_restart_cpu)
-	movl initial_stack, %ecx
-	movl %ecx, %esp
-	call *(initial_code)
-1:	jmp 1b
-SYM_FUNC_END(soft_restart_cpu)
-#endif
-
 /*
  * Non-boot CPU entry point; entered from trampoline.S
  * We can't lgdt here, because lgdt itself uses a data segment, but
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -375,7 +375,7 @@ SYM_CODE_END(secondary_startup_64)
 #include "verify_cpu.S"
 #include "sev_verify_cbit.S"
 
-#ifdef CONFIG_HOTPLUG_CPU
+#if defined(CONFIG_HOTPLUG_CPU) && defined(CONFIG_AMD_MEM_ENCRYPT)
 /*
  * Entry point for soft restart of a CPU. Invoked from xxx_play_dead() for
  * restarting the boot CPU or for restarting SEV guest CPUs after CPU hot