[XEN PATCH 2/3] x86/emul: use pseudo keyword fallthrough

[Federico Serafini <federico.serafini@xxxxxxxxxxx>]

Make explicit the fallthrough intetion by adding the pseudo keyword
where missing and refactor comments not following the agreed syntax.

This satisfies the requirements to deviate violations of
MISRA C:2012 Rule 16.3 "An unconditional break statement shall
terminate every switch-clause".

No functional change.

Signed-off-by: Federico Serafini <federico.serafini@xxxxxxxxxxx>
---
 xen/arch/x86/x86_emulate/decode.c      | 6 ++++--
 xen/arch/x86/x86_emulate/x86_emulate.c | 2 ++
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/xen/arch/x86/x86_emulate/decode.c 
b/xen/arch/x86/x86_emulate/decode.c
index 32b9276dc5..0a0751f2ed 100644
--- a/xen/arch/x86/x86_emulate/decode.c
+++ b/xen/arch/x86/x86_emulate/decode.c
@@ -1356,7 +1356,8 @@ int x86emul_decode(struct x86_emulate_state *s,
                         --disp8scale;
                     break;
                 }
-                /* vcvt{,t}s{s,d}2usi need special casing: fall through */
+                /* vcvt{,t}s{s,d}2usi need special casing. */
+                fallthrough;
             case 0x2c: /* vcvtts{s,d}2si need special casing */
             case 0x2d: /* vcvts{s,d}2si need special casing */
                 if ( evex_encoded() )
@@ -1530,7 +1531,8 @@ int x86emul_decode(struct x86_emulate_state *s,
                         disp8scale -= 1 + (s->evex.pfx == vex_66);
                     break;
                 }
-                /* vcvt{,t}sh2usi needs special casing: fall through */
+                /* vcvt{,t}sh2usi needs special casing. */
+                fallthrough;
             case 0x2c: case 0x2d: /* vcvt{,t}sh2si need special casing */
                 disp8scale = 1;
                 break;
diff --git a/xen/arch/x86/x86_emulate/x86_emulate.c 
b/xen/arch/x86/x86_emulate/x86_emulate.c
index 30674ec301..c38984b201 100644
--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -1460,6 +1460,7 @@ x86_emulate(
 
         d = (d & ~DstMask) | DstMem;
         /* Becomes a normal DstMem operation from here on. */
+        fallthrough;
     case DstMem:
         generate_exception_if(ea.type == OP_MEM && evex.z, X86_EXC_UD);
         if ( state->simd_size != simd_none )
@@ -1942,6 +1943,7 @@ x86_emulate(
             break;
         }
         generate_exception_if((modrm_reg & 7) != 0, X86_EXC_UD);
+        fallthrough;
     case 0x88 ... 0x8b: /* mov */
     case 0xa0 ... 0xa1: /* mov mem.offs,{%al,%ax,%eax,%rax} */
     case 0xa2 ... 0xa3: /* mov {%al,%ax,%eax,%rax},mem.offs */
-- 
2.43.0