[XEN PATCH 5/9] x86/cpu-policy: address violations of MISRA C Rule 10.1

[Nicola Vetrini <nicola.vetrini@xxxxxxxxxxx>]

The COUNT_LEAVES macro is introduced to avoid using an essentially
boolean value in a subtraction.

No functional change.

Signed-off-by: Nicola Vetrini <nicola.vetrini@xxxxxxxxxxx>
---
 xen/include/xen/lib/x86/cpu-policy.h | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/xen/include/xen/lib/x86/cpu-policy.h 
b/xen/include/xen/lib/x86/cpu-policy.h
index bab3eecda6c1..700993cc67e8 100644
--- a/xen/include/xen/lib/x86/cpu-policy.h
+++ b/xen/include/xen/lib/x86/cpu-policy.h
@@ -95,17 +95,18 @@ const char *x86_cpuid_vendor_to_str(unsigned int vendor);
 #define CPUID_GUEST_NR_EXTD       MAX(CPUID_GUEST_NR_EXTD_INTEL, \
                                       CPUID_GUEST_NR_EXTD_AMD)
 
+#define COUNT_LEAVES(X) ((X) - ((X) ? 1 : 0))
 /*
  * Maximum number of leaves a struct cpu_policy turns into when serialised for
  * interaction with the toolstack.  (Sum of all leaves in each union, less the
  * entries in basic which sub-unions hang off of.)
  */
-#define CPUID_MAX_SERIALISED_LEAVES                     \
-    (CPUID_GUEST_NR_BASIC +                             \
-     CPUID_GUEST_NR_FEAT   - !!CPUID_GUEST_NR_FEAT +    \
-     CPUID_GUEST_NR_CACHE  - !!CPUID_GUEST_NR_CACHE +   \
-     CPUID_GUEST_NR_TOPO   - !!CPUID_GUEST_NR_TOPO +    \
-     CPUID_GUEST_NR_XSTATE - !!CPUID_GUEST_NR_XSTATE +  \
+#define CPUID_MAX_SERIALISED_LEAVES         \
+    (CPUID_GUEST_NR_BASIC +                 \
+     COUNT_LEAVES(CPUID_GUEST_NR_FEAT) +    \
+     COUNT_LEAVES(CPUID_GUEST_NR_CACHE) +   \
+     COUNT_LEAVES(CPUID_GUEST_NR_TOPO) +    \
+     COUNT_LEAVES(CPUID_GUEST_NR_XSTATE) +  \
      CPUID_GUEST_NR_EXTD + 2 /* hv_limit and hv2_limit */ )
 
 /* Maximum number of MSRs written when serialising a cpu_policy. */
-- 
2.34.1