[tip:x86/cpu] x86/amd_nb: Check vendor in AMD-only functions

[tip-bot for Pu Wen]

Commit-ID:  b7a5cb4f220e78490735b2b984ad29b7d8e612a9
Gitweb:     https://git.kernel.org/tip/b7a5cb4f220e78490735b2b984ad29b7d8e612a9
Author:     Pu Wen <puwen@xxxxxxxx>
AuthorDate: Tue, 25 Sep 2018 22:45:01 +0800
Committer:  Borislav Petkov <bp@xxxxxxx>
CommitDate: Thu, 27 Sep 2018 18:28:58 +0200

x86/amd_nb: Check vendor in AMD-only functions

Exit early in functions which are meant to run on AMD only but which get
run on different vendor (VMs, etc).

 [ bp: rewrite commit message. ]

Signed-off-by: Pu Wen <puwen@xxxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Cc: bhelgaas@xxxxxxxxxx
Cc: tglx@xxxxxxxxxxxxx
Cc: mingo@xxxxxxxxxx
Cc: hpa@xxxxxxxxx
Cc: x86@xxxxxxxxxx
Cc: thomas.lendacky@xxxxxxx
Cc: helgaas@xxxxxxxxxx
Link: https://lkml.kernel.org/r/487d8078708baedaf63eb00a82251e228b58f1c2.1537885177.git.puwen@xxxxxxxx
---
 arch/x86/include/asm/amd_nb.h | 3 +++
 arch/x86/kernel/amd_nb.c      | 4 ++++
 2 files changed, 7 insertions(+)

diff --git a/arch/x86/include/asm/amd_nb.h b/arch/x86/include/asm/amd_nb.h
index fddb6d26239f..1ae4e5791afa 100644
--- a/arch/x86/include/asm/amd_nb.h
+++ b/arch/x86/include/asm/amd_nb.h
@@ -103,6 +103,9 @@ static inline u16 amd_pci_dev_to_node_id(struct pci_dev *pdev)
 
 static inline bool amd_gart_present(void)
 {
+	if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
+		return false;
+
 	/* GART present only on Fam15h, upto model 0fh */
 	if (boot_cpu_data.x86 == 0xf || boot_cpu_data.x86 == 0x10 ||
 	    (boot_cpu_data.x86 == 0x15 && boot_cpu_data.x86_model < 0x10))
diff --git a/arch/x86/kernel/amd_nb.c b/arch/x86/kernel/amd_nb.c
index b481b95bd8f6..b51c6b183a35 100644
--- a/arch/x86/kernel/amd_nb.c
+++ b/arch/x86/kernel/amd_nb.c
@@ -264,6 +264,10 @@ bool __init early_is_amd_nb(u32 device)
 	const struct pci_device_id *id;
 	u32 vendor = device & 0xffff;
 
+	if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD &&
+	    boot_cpu_data.x86_vendor != X86_VENDOR_HYGON)
+		return false;
+
 	device >>= 16;
 	for (id = amd_nb_misc_ids; id->vendor; id++)
 		if (vendor == id->vendor && device == id->device)