arm64: cpuinfo: ARMv7 compatable cpuinfo option

To be backwards compatable with the output of cpuinfo on an ARMv7,
print the features that were optional in ARMv7 but are required in
ARMv8.

Change-Id: Ic728f71be4a971adc79ef552f25cfbf95a4dac29
Signed-off-by: Alex Van Brunt <avanbrunt@nvidia.com>
Reviewed-on: http://git-master/r/366095
Reviewed-by: Richard Wiley <rwiley@nvidia.com>
Tested-by: Oskari Jaaskelainen <oskarij@nvidia.com>

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 787cee384e1ce760010d2314680b28c6f9058205..71c2a070ace4741e460e22cd9498fec0117cd91e 100644 (file)
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -217,6 +217,16 @@ config ARMV7_COMPAT
 
         If you want to execute ARMv7 applications, say Y
 
+config ARMV7_COMPAT_CPUINFO
+       bool "Report backwards compatible cpu features in /proc/cpuinfo"
+       depends on ARMV7_COMPAT
+       default y
+       help
+        This option makes /proc/cpuinfo list CPU features that an ARMv7 or
+        earlier kernel would report, but are not optional on an ARMv8 or later
+        processor.
+
+        If you want to execute ARMv7 applications, say Y
 
 source "mm/Kconfig"
 

diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index 3a06f1aa09025bfd16bee0cb0b6bb5118ffa2992..efe4850da9d02fea70357c6638fa8af73788d8a2 100644 (file)
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -420,9 +420,14 @@ static int c_show(struct seq_file *m, void *v)
        for (i = 0; hwcap_str[i]; i++)
                if (elf_hwcap & (1 << i))
                        seq_printf(m, "%s ", hwcap_str[i]);
+#ifdef CONFIG_ARMV7_COMPAT_CPUINFO
+       /* Print out the non-optional ARMv8 HW capabilities */
+       seq_printf(m, "wp half thumb fastmult vfp edsp neon vfpv3d16 tlsi ");
+       seq_printf(m, "vfpv4 idiva idivt ");
+#endif
 
        seq_printf(m, "\nCPU implementer\t: 0x%02x\n", read_cpuid_id() >> 24);
-       seq_printf(m, "CPU architecture: AArch64\n");
+       seq_printf(m, "CPU architecture: 8\n");
        seq_printf(m, "CPU variant\t: 0x%x\n", (read_cpuid_id() >> 20) & 15);
        seq_printf(m, "CPU part\t: 0x%03x\n", (read_cpuid_id() >> 4) & 0xfff);
        seq_printf(m, "CPU revision\t: %d\n", read_cpuid_id() & 15);