ARM: 7981/1: add support for AT_HWCAP2 ELF auxv entry

This enables AT_HWCAP2 for ARM. The generic support for this
new ELF auxv entry was added in commit 2171364d1a (powerpc:
Add HWCAP2 aux entry)

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/include/asm/hwcap.h

@@ -9,6 +9,7 @@
  * instruction set this cpu supports.
  */
 #define ELF_HWCAP	(elf_hwcap)
-extern unsigned int elf_hwcap;
+#define ELF_HWCAP2	(elf_hwcap2)
+extern unsigned int elf_hwcap, elf_hwcap2;
 #endif
 #endif

arch/arm/include/uapi/asm/hwcap.h

@@ -28,4 +28,8 @@
 #define HWCAP_LPAE	(1 << 20)
 #define HWCAP_EVTSTRM	(1 << 21)
 
+/*
+ * HWCAP2 flags - for elf_hwcap2 (in kernel) and AT_HWCAP2
+ */
+
 #endif /* _UAPI__ASMARM_HWCAP_H */

arch/arm/kernel/setup.c

@@ -100,6 +100,9 @@ EXPORT_SYMBOL(system_serial_high);
 unsigned int elf_hwcap __read_mostly;
 EXPORT_SYMBOL(elf_hwcap);
 
+unsigned int elf_hwcap2 __read_mostly;
+EXPORT_SYMBOL(elf_hwcap2);
+
 
 #ifdef MULTI_CPU
 struct processor processor __read_mostly;
@@ -1005,6 +1008,10 @@ static const char *hwcap_str[] = {
 	NULL
 };
 
+static const char *hwcap2_str[] = {
+	NULL
+};
+
 static int c_show(struct seq_file *m, void *v)
 {
 	int i, j;
@@ -1028,6 +1035,10 @@ static int c_show(struct seq_file *m, void *v)
 			if (elf_hwcap & (1 << j))
 				seq_printf(m, "%s ", hwcap_str[j]);
 
+		for (j = 0; hwcap2_str[j]; j++)
+			if (elf_hwcap2 & (1 << j))
+				seq_printf(m, "%s ", hwcap2_str[j]);
+
 		seq_printf(m, "\nCPU implementer\t: 0x%02x\n", cpuid >> 24);
 		seq_printf(m, "CPU architecture: %s\n",
 			   proc_arch[cpu_architecture()]);