UefiCpuPkg/MtrrLib: Update APIs related to set memory attributes.

Update APIs related to set memory attributes to handle the fixed MTRR
is not always supported.

There are 3 APIs in MtrrLib that can set memory attributes:
1. MtrrSetMemoryAttributesInMtrrSettings
2. MtrrSetMemoryAttributeInMtrrSettings
3. MtrrSetMemoryAttribute

The general idea applied in MtrrSetMemoryAttributesInMtrrSettings is:
1. MtrrLibPreMtrrChange saves the old MTRR default type which
   contains bit to enable fixed MTRR.
2. Main logic in MtrrSetMemoryAttributesInMtrrSettings applies
    memory attribute settings for below 1MB to variable MTRRs
    if fixed MTRR is not supported.
3. MtrrLibPostMtrrChange unconditionally sets E bit in MTRR default
    type MSR but only set FE bit when fixed MTRRs are modified.

Signed-off-by: Ray Ni <ray.ni@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Rahul Kumar <rahul1.kumar@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>

Reviewed-by: Eric Dong <eric.dong@intel.com>
Reviewed-by: Ray Ni <ray.ni@intel.com>

0 files changed, 0 insertions, 0 deletions