[PATCH V2] powerpc/signal: Add helper function to fetch quad word aligned pointer

[Anshuman Khandual]

This patch adds one helper function 'sigcontext_vmx_regs' which computes
quad word aligned pointer for 'vmx_reserve' array element in sigcontext
structure making the code more readable.

Signed-off-by: Anshuman Khandual <khandual at linux.vnet.ibm.com>
---
- Fixed some indentation problems
- Changed function name from 'vmx_reserve_addr' to 'sigcontext_vmx_regs'
- Added some documentation before the function

 arch/powerpc/kernel/signal_64.c | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index c7c24d2..bb9c939 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -74,6 +74,16 @@ static const char fmt64[] = KERN_INFO \
 	"%s[%d]: bad frame in %s: %016lx nip %016lx lr %016lx\n";
 
 /*
+ * This computes quad word aligned pointer for 'vmx_reserve' array element
+ * which is used primarily in assigning to the preceding pointer 'v_regs'
+ * in sigcontext structure.
+ */
+static elf_vrreg_t __user *sigcontext_vmx_regs(struct sigcontext __user *sc)
+{
+	return (elf_vrreg_t __user *) (((unsigned long)sc->vmx_reserve + 15) & ~0xful);
+}
+
+/*
  * Set up the sigcontext for the signal frame.
  */
 
@@ -90,7 +100,7 @@ static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
 	 * v_regs pointer or not
 	 */
 #ifdef CONFIG_ALTIVEC
-	elf_vrreg_t __user *v_regs = (elf_vrreg_t __user *)(((unsigned long)sc->vmx_reserve + 15) & ~0xful);
+	elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc);
 #endif
 	unsigned long msr = regs->msr;
 	long err = 0;
@@ -181,10 +191,8 @@ static long setup_tm_sigcontexts(struct sigcontext __user *sc,
 	 * v_regs pointer or not.
 	 */
 #ifdef CONFIG_ALTIVEC
-	elf_vrreg_t __user *v_regs = (elf_vrreg_t __user *)
-		(((unsigned long)sc->vmx_reserve + 15) & ~0xful);
-	elf_vrreg_t __user *tm_v_regs = (elf_vrreg_t __user *)
-		(((unsigned long)tm_sc->vmx_reserve + 15) & ~0xful);
+	elf_vrreg_t __user *v_regs = sigcontext_vmx_regs(sc);
+	elf_vrreg_t __user *tm_v_regs = sigcontext_vmx_regs(tm_sc);
 #endif
 	unsigned long msr = regs->msr;
 	long err = 0;
-- 
2.1.0