arm64: restore bogomips information in /proc/cpuinfo

commit 92e788b749862ebe9920360513a718e5dd4da7a9 upstream.

As previously reported, some userspace applications depend on bogomips
showed by /proc/cpuinfo. Although there is much less legacy impact on
aarch64 than arm, it does break libvirt.

This patch reverts commit 326b16db9f69 ("arm64: delay: don't bother
reporting bogomips in /proc/cpuinfo"), but with some tweak due to
context change and without the pr_info().

Fixes: 326b16db9f69 ("arm64: delay: don't bother reporting bogomips in /proc/cpuinfo")
Signed-off-by: Yang Shi <yang.shi@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
[ luis: backported to 3.16:
  - file rename: cpuinfo.c -> setup.c
  - linux/delay.h is already included
  - adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index 37655ae949b56014aa78ab015ab9268e4fc30024..5da0da6e7cf0d1719cf9014f9e8bd45fc09341f2 100644 (file)
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -502,6 +502,10 @@ static int c_show(struct seq_file *m, void *v)
                seq_printf(m, "processor\t: %d\n", i);
 #endif
 
+               seq_printf(m, "BogoMIPS\t: %lu.%02lu\n",
+                          loops_per_jiffy / (500000UL/HZ),
+                          loops_per_jiffy / (5000UL/HZ) % 100);
+
                /*
                 * Dump out the common processor features in a single line.
                 * Userspace should read the hwcaps with getauxval(AT_HWCAP)