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* Merge branch 'x86-cache-for-linus' of ↵Linus Torvalds2016-12-221-0/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cache allocation interface from Thomas Gleixner: "This provides support for Intel's Cache Allocation Technology, a cache partitioning mechanism. The interface is odd, but the hardware interface of that CAT stuff is odd as well. We tried hard to come up with an abstraction, but that only allows rather simple partitioning, but no way of sharing and dealing with the per package nature of this mechanism. In the end we decided to expose the allocation bitmaps directly so all combinations of the hardware can be utilized. There are two ways of associating a cache partition: - Task A task can be added to a resource group. It uses the cache partition associated to the group. - CPU All tasks which are not member of a resource group use the group to which the CPU they are running on is associated with. That allows for simple CPU based partitioning schemes. The main expected user sare: - Virtualization so a VM can only trash only the associated part of the cash w/o disturbing others - Real-Time systems to seperate RT and general workloads. - Latency sensitive enterprise workloads - In theory this also can be used to protect against cache side channel attacks" [ Intel RDT is "Resource Director Technology". The interface really is rather odd and very specific, which delayed this pull request while I was thinking about it. The pull request itself came in early during the merge window, I just delayed it until things had calmed down and I had more time. But people tell me they'll use this, and the good news is that it is _so_ specific that it's rather independent of anything else, and no user is going to depend on the interface since it's pretty rare. So if push comes to shove, we can just remove the interface and nothing will break ] * 'x86-cache-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits) x86/intel_rdt: Implement show_options() for resctrlfs x86/intel_rdt: Call intel_rdt_sched_in() with preemption disabled x86/intel_rdt: Update task closid immediately on CPU in rmdir and unmount x86/intel_rdt: Fix setting of closid when adding CPUs to a group x86/intel_rdt: Update percpu closid immeditately on CPUs affected by changee x86/intel_rdt: Reset per cpu closids on unmount x86/intel_rdt: Select KERNFS when enabling INTEL_RDT_A x86/intel_rdt: Prevent deadlock against hotplug lock x86/intel_rdt: Protect info directory from removal x86/intel_rdt: Add info files to Documentation x86/intel_rdt: Export the minimum number of set mask bits in sysfs x86/intel_rdt: Propagate error in rdt_mount() properly x86/intel_rdt: Add a missing #include MAINTAINERS: Add maintainer for Intel RDT resource allocation x86/intel_rdt: Add scheduler hook x86/intel_rdt: Add schemata file x86/intel_rdt: Add tasks files x86/intel_rdt: Add cpus file x86/intel_rdt: Add mkdir to resctrl file system x86/intel_rdt: Add "info" files to resctrl file system ...
| * cacheinfo: Introduce cache idFenghua Yu2016-10-261-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Fenghua 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.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | drivers: base: cacheinfo: fix x86 with CONFIG_OF enabledSudeep Holla2016-11-101-0/+1
|/ | | | | | | | | | | | | | | | | | | | | | 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: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* drivers/base: cacheinfo: fix annoying typo when DT nodes are absentWill Deacon2015-05-241-1/+1
| | | | | | | | | | | | 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: Will Deacon <will.deacon@arm.com> Acked-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* drivers: base: support cpu cache information interface to userspace via sysfsSudeep Holla2014-11-071-0/+100
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: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen 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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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