diff mbox series

[XEN,for-next,v2,4/8] x86_64/mm: express macro CNT using LOWEST_BIT

Message ID eb05327a3af71c883c3ff5ed3b4501a8859403d3.1697123806.git.nicola.vetrini@bugseng.com (mailing list archive)
State Superseded
Headers show
Series address violations of MISRA C:2012 Rule 10.1 | expand

Commit Message

Nicola Vetrini Oct. 12, 2023, 3:28 p.m. UTC 
The various definitions of macro CNT (and the related BUILD_BUG_ON)
can be rewritten using LOWEST_BIT, encapsulating a violation of
MISRA C:2012 Rule 10.1.

Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
---
 xen/arch/x86/x86_64/mm.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

--
2.34.1

Comments

Stefano Stabellini Oct. 12, 2023, 11:34 p.m. UTC | #1 
On Thu, 12 Oct 2023, Nicola Vetrini wrote:
> The various definitions of macro CNT (and the related BUILD_BUG_ON)
> can be rewritten using LOWEST_BIT, encapsulating a violation of
> MISRA C:2012 Rule 10.1.
> 
> Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>

Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
diff mbox series

Patch

diff --git a/xen/arch/x86/x86_64/mm.c b/xen/arch/x86/x86_64/mm.c
index c3ebb777144a..0eb7b71124f5 100644
--- a/xen/arch/x86/x86_64/mm.c
+++ b/xen/arch/x86/x86_64/mm.c
@@ -351,9 +351,9 @@  static int setup_compat_m2p_table(struct mem_hotadd_info *info)
                 ~((1UL << (L2_PAGETABLE_SHIFT - 2)) - 1) );

 #define MFN(x) (((x) << L2_PAGETABLE_SHIFT) / sizeof(unsigned int))
-#define CNT ((sizeof(*frame_table) & -sizeof(*frame_table)) / \
+#define CNT (LOWEST_BIT(sizeof(*frame_table)) / \
              sizeof(*compat_machine_to_phys_mapping))
-    BUILD_BUG_ON((sizeof(*frame_table) & -sizeof(*frame_table)) % \
+    BUILD_BUG_ON(LOWEST_BIT(sizeof(*frame_table)) % \
                  sizeof(*compat_machine_to_phys_mapping));

     for ( i = smap; i < emap; i += (1UL << (L2_PAGETABLE_SHIFT - 2)) )
@@ -410,10 +410,10 @@  static int setup_m2p_table(struct mem_hotadd_info *info)
     va = RO_MPT_VIRT_START + smap * sizeof(*machine_to_phys_mapping);

 #define MFN(x) (((x) << L2_PAGETABLE_SHIFT) / sizeof(unsigned long))
-#define CNT ((sizeof(*frame_table) & -sizeof(*frame_table)) / \
+#define CNT (LOWEST_BIT(sizeof(*frame_table)) / \
              sizeof(*machine_to_phys_mapping))

-    BUILD_BUG_ON((sizeof(*frame_table) & -sizeof(*frame_table)) % \
+    BUILD_BUG_ON(LOWEST_BIT(sizeof(*frame_table)) % \
                  sizeof(*machine_to_phys_mapping));

     i = smap;
@@ -539,7 +539,7 @@  void __init paging_init(void)
     mpt_size  = (max_page * BYTES_PER_LONG) + (1UL << L2_PAGETABLE_SHIFT) - 1;
     mpt_size &= ~((1UL << L2_PAGETABLE_SHIFT) - 1UL);
 #define MFN(x) (((x) << L2_PAGETABLE_SHIFT) / sizeof(unsigned long))
-#define CNT ((sizeof(*frame_table) & -sizeof(*frame_table)) / \
+#define CNT (LOWEST_BIT(sizeof(*frame_table)) / \
              sizeof(*machine_to_phys_mapping))
     BUILD_BUG_ON((sizeof(*frame_table) & ~sizeof(*frame_table)) % \
                  sizeof(*machine_to_phys_mapping));
@@ -666,7 +666,7 @@  void __init paging_init(void)
         mpt_size = 0;

 #define MFN(x) (((x) << L2_PAGETABLE_SHIFT) / sizeof(unsigned int))
-#define CNT ((sizeof(*frame_table) & -sizeof(*frame_table)) / \
+#define CNT (LOWEST_BIT(sizeof(*frame_table)) / \
              sizeof(*compat_machine_to_phys_mapping))
     BUILD_BUG_ON((sizeof(*frame_table) & ~sizeof(*frame_table)) % \
                  sizeof(*compat_machine_to_phys_mapping));