[PATCH v2] x86/platform: tidy do_platform_op() a little

[Jan Beulich <jbeulich@xxxxxxxx>]

The function has a few stray scopes and inconsistent use (indentation)
of break statements. Drop the stray braces and bring all the break-s in
line with one another. This in particular means dropping a redundant
break from XENPF_cpu_offline handling, pleasing Misra C:2012 rule 2.1.

No functional change intended.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
---
This is an alternative proposal to
https://lists.xen.org/archives/html/xen-devel/2023-12/msg01540.html.

A few more scopes could be eliminated if the various "cpu" variables
were consolidated to switch() of function scope.
---
v2: Also move an inconsistently indented break of an inner switch() (in
    XENPF_set_processor_pminfo handling).

--- unstable.orig/xen/arch/x86/platform_hypercall.c     2023-12-20 
10:27:41.690558632 +0100
+++ unstable/xen/arch/x86/platform_hypercall.c  2023-12-20 10:30:48.234533379 
+0100
@@ -258,7 +258,6 @@ ret_t do_platform_op(
         break;
 
     case XENPF_add_memtype:
-    {
         ret = mtrr_add_page(
             op->u.add_memtype.mfn,
             op->u.add_memtype.nr_mfns,
@@ -273,11 +272,9 @@ ret_t do_platform_op(
             if ( ret != 0 )
                 mtrr_del_page(ret, 0, 0);
         }
-    }
-    break;
+        break;
 
     case XENPF_del_memtype:
-    {
         if (op->u.del_memtype.handle == 0
             /* mtrr/main.c otherwise does a lookup */
             && (int)op->u.del_memtype.reg >= 0)
@@ -288,8 +285,7 @@ ret_t do_platform_op(
         }
         else
             ret = -EINVAL;
-    }
-    break;
+        break;
 
     case XENPF_read_memtype:
     {
@@ -306,8 +302,8 @@ ret_t do_platform_op(
             ret = __copy_field_to_guest(u_xenpf_op, op, u.read_memtype)
                   ? -EFAULT : 0;
         }
+        break;
     }
-    break;
 
     case XENPF_microcode_update:
     {
@@ -316,8 +312,8 @@ ret_t do_platform_op(
         guest_from_compat_handle(data, op->u.microcode.data);
 
         ret = microcode_update(data, op->u.microcode.length);
+        break;
     }
-    break;
 
     case XENPF_platform_quirk:
     {
@@ -340,8 +336,8 @@ ret_t do_platform_op(
             ret = -EINVAL;
             break;
         }
+        break;
     }
-    break;
 
     case XENPF_firmware_info:
         switch ( op->u.firmware_info.type )
@@ -521,8 +517,8 @@ ret_t do_platform_op(
 
         if ( ret == 0 && __copy_field_to_guest(u_xenpf_op, op, u.getidletime) )
             ret = -EFAULT;
+        break;
     }
-    break;
 
     case XENPF_set_processor_pminfo:
         switch ( op->u.set_pminfo.type )
@@ -560,8 +556,8 @@ ret_t do_platform_op(
 
             guest_from_compat_handle(pdc, op->u.set_pminfo.u.pdc);
             ret = acpi_set_pdc_bits(op->u.set_pminfo.id, pdc);
+            break;
         }
-        break;
 
         default:
             ret = -EINVAL;
@@ -601,8 +597,8 @@ ret_t do_platform_op(
         put_cpu_maps();
 
         ret = __copy_field_to_guest(u_xenpf_op, op, u.pcpu_info) ? -EFAULT : 0;
+        break;
     }
-    break;
 
     case XENPF_get_cpu_version:
     {
@@ -637,8 +633,8 @@ ret_t do_platform_op(
 
         if ( __copy_field_to_guest(u_xenpf_op, op, u.pcpu_version) )
             ret = -EFAULT;
+        break;
     }
-    break;
 
     case XENPF_get_ucode_revision:
     {
@@ -666,8 +662,8 @@ ret_t do_platform_op(
 
         if ( __copy_field_to_guest(u_xenpf_op, op, u.ucode_revision) )
             ret = -EFAULT;
+        break;
     }
-    break;
 
     case XENPF_cpu_online:
     {
@@ -725,7 +721,6 @@ ret_t do_platform_op(
             0, cpu_down_helper, (void *)(unsigned long)cpu);
         break;
     }
-    break;
 
     case XENPF_cpu_hotadd:
         ret = xsm_resource_plug_core(XSM_HOOK);
@@ -735,7 +730,7 @@ ret_t do_platform_op(
         ret = cpu_add(op->u.cpu_add.apic_id,
                       op->u.cpu_add.acpi_id,
                       op->u.cpu_add.pxm);
-    break;
+        break;
 
     case XENPF_mem_hotadd:
         ret = xsm_resource_plug_core(XSM_HOOK);
@@ -775,8 +770,8 @@ ret_t do_platform_op(
             ret = -EINVAL;
             break;
         }
+        break;
     }
-    break;
 
     case XENPF_resource_op:
     {
@@ -842,8 +837,8 @@ ret_t do_platform_op(
             ret = ra.nr_done;
 
         xfree(ra.entries);
+        break;
     }
-    break;
 
     case XENPF_get_symbol:
     {
@@ -870,8 +865,8 @@ ret_t do_platform_op(
             ret = -EFAULT;
         if ( !ret && __copy_field_to_guest(u_xenpf_op, op, u.symdata) )
             ret = -EFAULT;
+        break;
     }
-    break;
 
 #ifdef CONFIG_VIDEO
     case XENPF_get_dom0_console: