[for-4.18][PATCH 1/2] xen/x86: Add family guards to the is_zen[12]_uarch() macros

[Alejandro Vallejo <alejandro.vallejo@cloud.com>]

It slightly simplifies the code that uses them at no real cost because the
code is very rarely executed. This makes it harder to confuse zen uarches
due to missing or mistaken family checks.

No functional change intended.

Signed-off-by: Alejandro Vallejo <alejandro.vallejo@cloud.com>
---
 xen/arch/x86/cpu/amd.c         | 5 ++---
 xen/arch/x86/include/asm/amd.h | 9 +++++----
 xen/arch/x86/spec_ctrl.c       | 3 ---
 3 files changed, 7 insertions(+), 10 deletions(-)

diff --git a/xen/arch/x86/cpu/amd.c b/xen/arch/x86/cpu/amd.c
index 4f27187f92..22aa8c0085 100644
--- a/xen/arch/x86/cpu/amd.c
+++ b/xen/arch/x86/cpu/amd.c
@@ -1056,8 +1056,7 @@ static void cf_check init_amd(struct cpuinfo_x86 *c)
 
 	amd_init_ssbd(c);
 
-	if (c->x86 == 0x17)
-		amd_init_spectral_chicken();
+	amd_init_spectral_chicken();
 
 	/* Probe for NSCB on Zen2 CPUs when not virtualised */
 	if (!cpu_has_hypervisor && !cpu_has_nscb && c == &boot_cpu_data &&
@@ -1293,7 +1292,7 @@ static int __init cf_check zen2_c6_errata_check(void)
 	 */
 	s_time_t delta;
 
-	if (cpu_has_hypervisor || boot_cpu_data.x86 != 0x17 || !is_zen2_uarch())
+	if (cpu_has_hypervisor || !is_zen2_uarch())
 		return 0;
 
 	/*
diff --git a/xen/arch/x86/include/asm/amd.h b/xen/arch/x86/include/asm/amd.h
index d862cb7972..5a40bcc2ba 100644
--- a/xen/arch/x86/include/asm/amd.h
+++ b/xen/arch/x86/include/asm/amd.h
@@ -145,11 +145,12 @@
  * Hygon (Fam18h) but without simple model number rules.  Instead, use STIBP
  * as a heuristic that distinguishes the two.
  *
- * The caller is required to perform the appropriate vendor/family checks
- * first.
+ * The caller is required to perform the appropriate vendor check first.
  */
-#define is_zen1_uarch() (!boot_cpu_has(X86_FEATURE_AMD_STIBP))
-#define is_zen2_uarch()   boot_cpu_has(X86_FEATURE_AMD_STIBP)
+#define is_zen1_uarch() ((boot_cpu_data.x86 == 0x17 || boot_cpu_data.x86 == 0x18) && \
+                         !boot_cpu_has(X86_FEATURE_AMD_STIBP))
+#define is_zen2_uarch() (boot_cpu_data.x86 == 0x17 && \
+                         boot_cpu_has(X86_FEATURE_AMD_STIBP))
 
 struct cpuinfo_x86;
 int cpu_has_amd_erratum(const struct cpuinfo_x86 *, int, ...);
diff --git a/xen/arch/x86/spec_ctrl.c b/xen/arch/x86/spec_ctrl.c
index 6fd7d44ce4..508c454516 100644
--- a/xen/arch/x86/spec_ctrl.c
+++ b/xen/arch/x86/spec_ctrl.c
@@ -976,9 +976,6 @@ static bool __init has_div_vuln(void)
            (X86_VENDOR_AMD | X86_VENDOR_HYGON)) )
         return false;
 
-    if ( boot_cpu_data.x86 != 0x17 && boot_cpu_data.x86 != 0x18 )
-        return false;
-
     return is_zen1_uarch();
 }
 
-- 
2.34.1