Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 142 insertions, 0 deletions

diff --git a/arch/x86/kernel/verify_cpu.S b/arch/x86/kernel/verify_cpu.S
new file mode 100644
index 000000000..3d3c2f71f
--- /dev/null
+++ b/arch/x86/kernel/verify_cpu.S
@@ -0,0 +1,142 @@
+/*
+ *
+ *	verify_cpu.S - Code for cpu long mode and SSE verification. This
+ *	code has been borrowed from boot/setup.S and was introduced by
+ * 	Andi Kleen.
+ *
+ *	Copyright (c) 2007  Andi Kleen (ak@suse.de)
+ *	Copyright (c) 2007  Eric Biederman (ebiederm@xmission.com)
+ *	Copyright (c) 2007  Vivek Goyal (vgoyal@in.ibm.com)
+ *	Copyright (c) 2010  Kees Cook (kees.cook@canonical.com)
+ *
+ * 	This source code is licensed under the GNU General Public License,
+ * 	Version 2.  See the file COPYING for more details.
+ *
+ *	This is a common code for verification whether CPU supports
+ * 	long mode and SSE or not. It is not called directly instead this
+ *	file is included at various places and compiled in that context.
+ *	This file is expected to run in 32bit code.  Currently:
+ *
+ *	arch/x86/boot/compressed/head_64.S: Boot cpu verification
+ *	arch/x86/kernel/trampoline_64.S: secondary processor verification
+ *	arch/x86/kernel/head_32.S: processor startup
+ *
+ *	verify_cpu, returns the status of longmode and SSE in register %eax.
+ *		0: Success    1: Failure
+ *
+ *	On Intel, the XD_DISABLE flag will be cleared as a side-effect.
+ *
+ * 	The caller needs to check for the error code and take the action
+ * 	appropriately. Either display a message or halt.
+ */
+
+#include <asm/cpufeatures.h>
+#include <asm/msr-index.h>
+
+ENTRY(verify_cpu)
+	pushf				# Save caller passed flags
+	push	$0			# Kill any dangerous flags
+	popf
+
+#ifndef __x86_64__
+	pushfl				# standard way to check for cpuid
+	popl	%eax
+	movl	%eax,%ebx
+	xorl	$0x200000,%eax
+	pushl	%eax
+	popfl
+	pushfl
+	popl	%eax
+	cmpl	%eax,%ebx
+	jz	.Lverify_cpu_no_longmode	# cpu has no cpuid
+#endif
+
+	movl	$0x0,%eax		# See if cpuid 1 is implemented
+	cpuid
+	cmpl	$0x1,%eax
+	jb	.Lverify_cpu_no_longmode	# no cpuid 1
+
+	xor	%di,%di
+	cmpl	$0x68747541,%ebx	# AuthenticAMD
+	jnz	.Lverify_cpu_noamd
+	cmpl	$0x69746e65,%edx
+	jnz	.Lverify_cpu_noamd
+	cmpl	$0x444d4163,%ecx
+	jnz	.Lverify_cpu_noamd
+	mov	$1,%di			# cpu is from AMD
+	jmp	.Lverify_cpu_check
+
+.Lverify_cpu_noamd:
+	cmpl	$0x756e6547,%ebx        # GenuineIntel?
+	jnz	.Lverify_cpu_check
+	cmpl	$0x49656e69,%edx
+	jnz	.Lverify_cpu_check
+	cmpl	$0x6c65746e,%ecx
+	jnz	.Lverify_cpu_check
+
+	# only call IA32_MISC_ENABLE when:
+	# family > 6 || (family == 6 && model >= 0xd)
+	movl	$0x1, %eax		# check CPU family and model
+	cpuid
+	movl	%eax, %ecx
+
+	andl	$0x0ff00f00, %eax	# mask family and extended family
+	shrl	$8, %eax
+	cmpl	$6, %eax
+	ja	.Lverify_cpu_clear_xd	# family > 6, ok
+	jb	.Lverify_cpu_check	# family < 6, skip
+
+	andl	$0x000f00f0, %ecx	# mask model and extended model
+	shrl	$4, %ecx
+	cmpl	$0xd, %ecx
+	jb	.Lverify_cpu_check	# family == 6, model < 0xd, skip
+
+.Lverify_cpu_clear_xd:
+	movl	$MSR_IA32_MISC_ENABLE, %ecx
+	rdmsr
+	btrl	$2, %edx		# clear MSR_IA32_MISC_ENABLE_XD_DISABLE
+	jnc	.Lverify_cpu_check	# only write MSR if bit was changed
+	wrmsr
+
+.Lverify_cpu_check:
+	movl    $0x1,%eax		# Does the cpu have what it takes
+	cpuid
+	andl	$REQUIRED_MASK0,%edx
+	xorl	$REQUIRED_MASK0,%edx
+	jnz	.Lverify_cpu_no_longmode
+
+	movl    $0x80000000,%eax	# See if extended cpuid is implemented
+	cpuid
+	cmpl    $0x80000001,%eax
+	jb      .Lverify_cpu_no_longmode	# no extended cpuid
+
+	movl    $0x80000001,%eax	# Does the cpu have what it takes
+	cpuid
+	andl    $REQUIRED_MASK1,%edx
+	xorl    $REQUIRED_MASK1,%edx
+	jnz     .Lverify_cpu_no_longmode
+
+.Lverify_cpu_sse_test:
+	movl	$1,%eax
+	cpuid
+	andl	$SSE_MASK,%edx
+	cmpl	$SSE_MASK,%edx
+	je	.Lverify_cpu_sse_ok
+	test	%di,%di
+	jz	.Lverify_cpu_no_longmode	# only try to force SSE on AMD
+	movl	$MSR_K7_HWCR,%ecx
+	rdmsr
+	btr	$15,%eax		# enable SSE
+	wrmsr
+	xor	%di,%di			# don't loop
+	jmp	.Lverify_cpu_sse_test	# try again
+
+.Lverify_cpu_no_longmode:
+	popf				# Restore caller passed flags
+	movl $1,%eax
+	ret
+.Lverify_cpu_sse_ok:
+	popf				# Restore caller passed flags
+	xorl %eax, %eax
+	ret
+ENDPROC(verify_cpu)