xen: address violations of MISRA C:2012 Rule 11.8

Remove or amend casts to comply with Rule 11.8.

Fix violations by adding missing const qualifier in cast.
Fix violations by removing unnecessary cast.
Change type of operands from char* to uintptr_t: uintptr_t is
the appropriate type for memory address operations.

No functional changes.

Signed-off-by: Maria Celeste Cesario  <maria.celeste.cesario@bugseng.com>
Signed-off-by: Simone Ballarin  <simone.ballarin@bugseng.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>

xen/arch/arm/dom0less-build.c

@@ -354,7 +354,7 @@ static int __init handle_passthrough_prop(struct kernel_info *kinfo,
     if ( node == NULL )
     {
         printk(XENLOG_ERR "Couldn't find node %s in host_dt!\n",
-               (char *)xen_path->data);
+               xen_path->data);
         return -EINVAL;
     }
 

xen/arch/arm/include/asm/atomic.h

@@ -154,7 +154,7 @@ static always_inline void write_atomic_size(volatile void *p,
  */
 static inline int atomic_read(const atomic_t *v)
 {
-    return *(volatile int *)&v->counter;
+    return *(const volatile int *)&v->counter;
 }
 
 static inline int _atomic_read(atomic_t v)

xen/arch/arm/include/asm/regs.h

@@ -48,7 +48,7 @@ static inline bool regs_mode_is_32bit(const struct cpu_user_regs *regs)
 
 static inline bool guest_mode(const struct cpu_user_regs *r)
 {
-    unsigned long diff = (char *)guest_cpu_user_regs() - (char *)(r);
+    unsigned long diff = (uintptr_t)guest_cpu_user_regs() - (uintptr_t)(r);
     /* Frame pointer must point into current CPU stack. */
     ASSERT(diff < STACK_SIZE);
     /* If not a guest frame, it must be a hypervisor frame. */

xen/arch/x86/include/asm/regs.h

@@ -6,7 +6,7 @@
 
 #define guest_mode(r)                                                         \
 ({                                                                            \
-    unsigned long diff = (char *)guest_cpu_user_regs() - (char *)(r);         \
+    unsigned long diff = (uintptr_t)guest_cpu_user_regs() - (uintptr_t)(r);   \
     /* Frame pointer must point into current CPU stack. */                    \
     ASSERT(diff < STACK_SIZE);                                                \
     /* If not a guest frame, it must be a hypervisor frame. */                \