[PATCH v5 03/16] x86/mtrr: get MTRR number and support TOP_MEM2

Pu Wen
2018-08-29T12:43:42Z

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

The MtrrFixDramModEn bit on Hygon platform should also be set to 1
during BIOS initialization of the fixed MTRRs, then cleared to 0 for
operation.

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

Signed-off-by: Pu Wen <puwen@hygon.cn>
---
arch/x86/kernel/cpu/mtrr/cleanup.c | 3 ++-
arch/x86/kernel/cpu/mtrr/generic.c | 5 +++--
arch/x86/kernel/cpu/mtrr/mtrr.c | 2 +-
3 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/cpu/mtrr/cleanup.c b/arch/x86/kernel/cpu/mtrr/cleanup.c
index 765afd5..3668c5d 100644
--- 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/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c
index e12ee86..77c3eaa 100644
--- a/arch/x86/kernel/cpu/mtrr/generic.c
+++ b/arch/x86/kernel/cpu/mtrr/generic.c
@@ -49,8 +49,9 @@ static inline void k8_check_syscfg_dram_mod_en(void)
{
u32 lo, hi;

- if (!((boot_cpu_data.x86_vendor == X86_VENDOR_AMD) &&
- (boot_cpu_data.x86 >= 0x0f)))
+ if (!((boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
+ boot_cpu_data.x86 >= 0x0f) ||
+ boot_cpu_data.x86_vendor == X86_VENDOR_HYGON))
return;

rdmsr(MSR_K8_SYSCFG, lo, hi);
diff --git a/arch/x86/kernel/cpu/mtrr/mtrr.c b/arch/x86/kernel/cpu/mtrr/mtrr.c
index 9a19c80..507039c 100644
--- 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;
--
2.7.4