x86/cpu/mtrr: Support TOP_MEM2 and get MTRR number

The Hygon Dhyana CPU has a special MSR way to force WB for memory >4GB,
and support TOP_MEM2. Therefore, it is necessary to add Hygon Dhyana
support in amd_special_default_mtrr().

The number of variable MTRRs for Hygon is 2 as AMD's.

Signed-off-by: Pu Wen <puwen@hygon.cn>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: tglx@linutronix.de
Cc: mingo@redhat.com
Cc: hpa@zytor.com
Cc: x86@kernel.org
Cc: thomas.lendacky@amd.com
Link: https://lkml.kernel.org/r/8246f81648d014601de3812ade40e85d9c50d9b3.1537533369.git.puwen@hygon.cn

diff --git a/arch/x86/kernel/cpu/mtrr/cleanup.c b/arch/x86/kernel/cpu/mtrr/cleanup.c
index 765afd5..3668c5d 100644 (file)
--- a/arch/x86/kernel/cpu/mtrr/cleanup.c
+++ b/arch/x86/kernel/cpu/mtrr/cleanup.c
@@ -831,7 +831,8 @@ int __init amd_special_default_mtrr(void)
 {
        u32 l, h;
 
-       if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
+       if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD &&
+           boot_cpu_data.x86_vendor != X86_VENDOR_HYGON)
                return 0;
        if (boot_cpu_data.x86 < 0xf)
                return 0;

diff --git a/arch/x86/kernel/cpu/mtrr/mtrr.c b/arch/x86/kernel/cpu/mtrr/mtrr.c
index 9a19c80..507039c 100644 (file)
--- a/arch/x86/kernel/cpu/mtrr/mtrr.c
+++ b/arch/x86/kernel/cpu/mtrr/mtrr.c
@@ -127,7 +127,7 @@ static void __init set_num_var_ranges(void)
 
        if (use_intel())
                rdmsr(MSR_MTRRcap, config, dummy);
-       else if (is_cpu(AMD))
+       else if (is_cpu(AMD) || is_cpu(HYGON))
                config = 2;
        else if (is_cpu(CYRIX) || is_cpu(CENTAUR))
                config = 8;