From cdcaf2e07354ca74539aecb5f23f0ed35b3c7260 Mon Sep 17 00:00:00 2001
From: Konstantin Belousov <kib@FreeBSD.org>
Date: Thu, 12 Sep 2024 05:42:23 +0300
Subject: [PATCH] amd64 la57_trampoline: turn off global pages and PCID before
 turning off paging

(cherry picked from commit 1be58e67eb24024bc808357771579d396679ecb0)
---
 sys/amd64/amd64/locore.S | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/sys/amd64/amd64/locore.S b/sys/amd64/amd64/locore.S
index 9a991402cdc..d05f38dbba0 100644
--- a/sys/amd64/amd64/locore.S
+++ b/sys/amd64/amd64/locore.S
@@ -94,6 +94,8 @@ ENTRY(la57_trampoline)
 	movq	%rsp,%r11
 	movq	%rbx,%r10
 	movq	%rbp,%r9
+	movq	%cr4,%r8
+	orl	$CR4_LA57,%r8d
 	leaq	la57_trampoline_end(%rip),%rsp
 
 	movq	%cr0,%rbp
@@ -110,6 +112,10 @@ ENTRY(la57_trampoline)
 l1:	movl	$(3<<3),%eax
 	movl	%eax,%ss
 
+	movl	%cr4,%eax
+	andl	$~(CR4_PGE | CR4_PCIDE),%eax
+	movl	%eax,%cr4
+
 	movl	%ebp,%eax
 	andl	$~CR0_PG,%eax
 	movl	%eax,%cr0
@@ -140,6 +146,7 @@ l1:	movl	$(3<<3),%eax
 l2:	movq	%r11,%rsp
 	movq	%r10,%rbx
 	movq	%r9,%rbp
+	movq	%r8,%cr4
 	retq
 	.p2align 4,0
 ENTRY(la57_trampoline_gdt_desc)