With CONFIG_OF enabled on x86, we get the following error on boot:
"
	Failed to find cpu0 device node
 	Unable to detect cache hierarchy from DT for CPU 0
"
and the cacheinfo fails to get populated in the corresponding sysfs
entries. This is because cache_setup_of_node looks for of_node for
setting up the shared cpu_map without checking that it's already
populated in the architecture specific callback.

In order to indicate that the shared cpu_map is already populated, this
patch introduces a boolean `cpu_map_populated` in struct cpu_cacheinfo
that can be used by the generic code to skip cache_shared_cpu_map_setup.

This patch also sets that boolean for x86.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Cache management software needs an id for each instance of a cache of
a particular type.

The current cacheinfo structure does not provide any information about
the underlying hardware so there is no way to expose it.

Hardware with cache management features provides means (cpuid, enumeration
etc.) to retrieve the hardware id of a particular cache instance. Cache
instances which share hardware have the same hardware id.

Add an 'id' field to struct cacheinfo to store this information. Expose
this information under the /sys/devices/system/cpu/cpu*/cache/index*/
directory as well.
Signed-off-by: NFenghua Yu <fenghua.yu@intel.com>
Cc: "Ravi V Shankar" <ravi.v.shankar@intel.com>
Cc: "Tony Luck" <tony.luck@intel.com>
Cc: "David Carrillo-Cisneros" <davidcc@google.com>
Cc: "Sai Prakhya" <sai.praneeth.prakhya@intel.com>
Cc: "Peter Zijlstra" <peterz@infradead.org>
Cc: "Stephane Eranian" <eranian@google.com>
Cc: "Dave Hansen" <dave.hansen@intel.com>
Cc: "Shaohua Li" <shli@fb.com>
Cc: "Nilay Vaish" <nilayvaish@gmail.com>
Cc: "Vikas Shivappa" <vikas.shivappa@linux.intel.com>
Cc: "Ingo Molnar" <mingo@elte.hu>
Cc: "Borislav Petkov" <bp@suse.de>
Cc: "H. Peter Anvin" <h.peter.anvin@intel.com>
Link: http://lkml.kernel.org/r/1477142405-32078-3-git-send-email-fenghua.yu@intel.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

s/hierarcy/hierarchy/

Maybe the typo will annoy people enough so that they add the missing
nodes to their device-tree files, but I still think this is better off
fixed.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Acked-by: NSudeep Holla <sudeep.holla@arm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch adds initial support for providing processor cache information
to userspace through sysfs interface. This is based on already existing
implementations(x86, ia64, s390 and powerpc) and hence the interface is
intended to be fully compatible.

The main purpose of this generic support is to avoid further code
duplication to support new architectures and also to unify all the existing
different implementations.

This implementation maintains the hierarchy of cache objects which reflects
the system's cache topology. Cache devices are instantiated as needed as
CPUs come online. The cache information is replicated per-cpu even if they are
shared. A per-cpu array of cache information maintained is used mainly for
sysfs-related book keeping.

It also implements the shared_cpu_map attribute, which is essential for
enabling both kernel and user-space to discover the system's overall cache
topology.

This patch also add the missing ABI documentation for the cacheinfo sysfs
interface already, which is well defined and widely used.
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Tested-by: NStephen Boyd <sboyd@codeaurora.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-api@vger.kernel.org
Cc: linux390@de.ibm.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-ia64@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
Cc: x86@kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>