x86/CPU/AMD: Properly check the TSA microcode

In order to simplify backports, I resorted to an older version of the
microcode revision checking which didn't pull in the whole struct
x86_cpu_id matching machinery.

My simpler method, however, forgot to add the extended CPU model to the
patch revision, which lead to mismatches when determining whether TSA
mitigation support is present.

So add that forgotten extended model.

This is a stable-only fix and the preference is to do it this way
because it is a lot simpler. Also, the Fixes: tag below points to the
respective stable patch.

Fixes: 7a0395f ("x86/bugs: Add a Transient Scheduler Attacks mitigation")
Reported-by: Thomas Voegtle <[email protected]>
Signed-off-by: Borislav Petkov (AMD) <[email protected]>
Tested-by: Thomas Voegtle <[email protected]>
Message-ID: <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: bp3tk0v

arch/x86/kernel/cpu/amd.c

@@ -376,6 +376,7 @@ static bool amd_check_tsa_microcode(void)
 
 	p.ext_fam	= c->x86 - 0xf;
 	p.model		= c->x86_model;
+	p.ext_model	= c->x86_model >> 4;
 	p.stepping	= c->x86_stepping;
 
 	if (cpu_has(c, X86_FEATURE_ZEN3) ||