x86/topology: Fix AMD core count

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+x86 Topology
+============
+
+This documents and clarifies the main aspects of x86 topology modelling
+and representation in the kernel. Update/change when doing changes to
+the respective code.
+
+Started by Thomas Gleixner <[email protected]> and Borislav Petkov <[email protected]>.
+
+The main aim of the topology facilities is to present adequate
+interfaces to code which needs to know/query/use the structure of the
+running system wrt threads, cores, packages, etc.
+
+The kernel does not care about the concept of physical sockets because
+a socket has no relevance to software. It's an electromechanical
+component. In the past a socket always contained a single package
+(see below), but with the advent of Multi Chip Modules (MCM) a socket
+can hold more than one package. So there might be still references to
+sockets in the code, but they are of historical nature and should be
+cleaned up.
+
+The topology of a system is described in the units of:
+
+    - packages
+    - cores
+    - threads
+
+* Package:
+
+  Packages contain a number of cores plus shared resources, e.g. DRAM
+  controller, shared caches etc.
+
+  AMD nomenclature for package is 'Node'.
+
+  Package-related topology information in the kernel:
+
+  - cpuinfo_x86.x86_max_cores:
+
+    The number of cores in a package. This information is retrieved via CPUID.
+
+  - cpuinfo_x86.phys_proc_id:
+
+    The physical ID of the package. This information is retrieved via CPUID
+    and deduced from the APIC IDs of the cores in the package.
+
+  - cpuinfo_x86.logical_id:
+
+    The logical ID of the package. As we do not trust BIOSes to enumerate the
+    packages in a consistent way, we introduced the concept of logical package
+    ID so we can sanely calculate the number of maximum possible packages in
+    the system and have the packages enumerated linearly.
+
+  - topology_max_packages():
+
+    The maximum possible number of packages in the system. Helpful for per
+    package facilities to preallocate per package information.
+
+
+* Cores:
+
+  A core consists of 1 or more threads. It does not matter whether the threads
+  are SMT- or CMT-type threads.
+
+  AMDs nomenclature for a CMT core is "Compute Unit". The kernel always uses
+  "core".
+
+  Core-related topology information in the kernel:
+
+  - smp_num_siblings:
+
+    The number of threads in a core. The number of threads in a package can be
+    calculated by:
+
+    	threads_per_package = cpuinfo_x86.x86_max_cores * smp_num_siblings
+
+
+* Threads:
+
+  A thread is a single scheduling unit. It's the equivalent to a logical Linux
+  CPU.
+
+  AMDs nomenclature for CMT threads is "Compute Unit Core". The kernel always
+  uses "thread".
+
+  Thread-related topology information in the kernel:
+
+  - topology_core_cpumask():
+
+    The cpumask contains all online threads in the package to which a thread
+    belongs.
+
+    The number of online threads is also printed in /proc/cpuinfo "siblings."
+
+  - topology_sibling_mask():
+
+    The cpumask contains all online threads in the core to which a thread
+    belongs.
+
+   - topology_logical_package_id():
+
+    The logical package ID to which a thread belongs.
+
+   - topology_physical_package_id():
+
+    The physical package ID to which a thread belongs.
+
+   - topology_core_id();
+
+    The ID of the core to which a thread belongs. It is also printed in /proc/cpuinfo
+    "core_id."
+
+
+
+System topology examples
+
+Note:
+
+The alternative Linux CPU enumeration depends on how the BIOS enumerates the
+threads. Many BIOSes enumerate all threads 0 first and then all threads 1.
+That has the "advantage" that the logical Linux CPU numbers of threads 0 stay
+the same whether threads are enabled or not. That's merely an implementation
+detail and has no practical impact.
+
+1) Single Package, Single Core
+
+   [package 0] -> [core 0] -> [thread 0] -> Linux CPU 0
+
+2) Single Package, Dual Core
+
+   a) One thread per core
+
+      [package 0] -> [core 0] -> [thread 0] -> Linux CPU 0
+	          -> [core 1] -> [thread 0] -> Linux CPU 1
+
+   b) Two threads per core
+
+      [package 0] -> [core 0] -> [thread 0] -> Linux CPU 0
+   	         	      -> [thread 1] -> Linux CPU 1
+      	          -> [core 1] -> [thread 0] -> Linux CPU 2
+   	         	      -> [thread 1] -> Linux CPU 3
+
+      Alternative enumeration:
+
+      [package 0] -> [core 0] -> [thread 0] -> Linux CPU 0
+   	         	      -> [thread 1] -> Linux CPU 2
+      	          -> [core 1] -> [thread 0] -> Linux CPU 1
+   	         	      -> [thread 1] -> Linux CPU 3
+
+      AMD nomenclature for CMT systems:
+
+      [node 0] -> [Compute Unit 0] -> [Compute Unit Core 0] -> Linux CPU 0
+   	       		           -> [Compute Unit Core 1] -> Linux CPU 1
+               -> [Compute Unit 1] -> [Compute Unit Core 0] -> Linux CPU 2
+   	       		           -> [Compute Unit Core 1] -> Linux CPU 3
+
+4) Dual Package, Dual Core
+
+   a) One thread per core
+
+      [package 0] -> [core 0] -> [thread 0] -> Linux CPU 0
+    	          -> [core 1] -> [thread 0] -> Linux CPU 1
+
+      [package 1] -> [core 0] -> [thread 0] -> Linux CPU 2
+   	          -> [core 1] -> [thread 0] -> Linux CPU 3
+
+   b) Two threads per core
+
+      [package 0] -> [core 0] -> [thread 0] -> Linux CPU 0
+   	           	      -> [thread 1] -> Linux CPU 1
+      	          -> [core 1] -> [thread 0] -> Linux CPU 2
+   	         	      -> [thread 1] -> Linux CPU 3
+
+      [package 1] -> [core 0] -> [thread 0] -> Linux CPU 4
+   	         	      -> [thread 1] -> Linux CPU 5
+      	          -> [core 1] -> [thread 0] -> Linux CPU 6
+   	         	      -> [thread 1] -> Linux CPU 7
+
+      Alternative enumeration:
+
+      [package 0] -> [core 0] -> [thread 0] -> Linux CPU 0
+   	         	      -> [thread 1] -> Linux CPU 4
+       	          -> [core 1] -> [thread 0] -> Linux CPU 1
+   	         	      -> [thread 1] -> Linux CPU 5
+
+      [package 1] -> [core 0] -> [thread 0] -> Linux CPU 2
+   	         	      -> [thread 1] -> Linux CPU 6
+      	          -> [core 1] -> [thread 0] -> Linux CPU 3
+   	         	      -> [thread 1] -> Linux CPU 7
+
+      AMD nomenclature for CMT systems:
+
+      [node 0] -> [Compute Unit 0] -> [Compute Unit Core 0] -> Linux CPU 0
+   	       		           -> [Compute Unit Core 1] -> Linux CPU 1
+               -> [Compute Unit 1] -> [Compute Unit Core 0] -> Linux CPU 2
+   	       		           -> [Compute Unit Core 1] -> Linux CPU 3
+
+      [node 1] -> [Compute Unit 0] -> [Compute Unit Core 0] -> Linux CPU 4
+   	       		           -> [Compute Unit Core 1] -> Linux CPU 5
+               -> [Compute Unit 1] -> [Compute Unit Core 0] -> Linux CPU 6
+   	       		           -> [Compute Unit Core 1] -> Linux CPU 7
+
+

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+x86 Topology
+============
+
+This documents and clarifies the main aspects of x86 topology modelling
+and representation in the kernel. Update/change when doing changes to
+the respective code.
+
+The architecture-agnostic topology definitions are in
+Documentation/cputopology.txt. This file holds x86-specific
+differences/specialities which must not necessarily apply to the generic
+definitions. Thus, the way to read up on Linux topology on x86 is to
+start with the generic one and look at this one in parallel for the x86
+specifics.
+
+Needless to say, code should use the generic functions - this file is
+*only* here to *document* the inner workings of x86 topology.
+
+Started by Thomas Gleixner <[email protected]> and Borislav Petkov <[email protected]>.
+
+The main aim of the topology facilities is to present adequate
+interfaces to code which needs to know/query/use the structure of the
+running system wrt threads, cores, packages, etc.
+
+The kernel does not care about the concept of physical sockets because
+a socket has no relevance to software. It's an electromechanical
+component. In the past a socket always contained a single package
+(see below), but with the advent of Multi Chip Modules (MCM) a socket
+can hold more than one package. So there might be still references to
+sockets in the code, but they are of historical nature and should be
+cleaned up.
+
+The topology of a system is described in the units of:
+
+    - packages
+    - cores
+    - threads
+
+* Package:
+
+  Packages contain a number of cores plus shared resources, e.g. DRAM
+  controller, shared caches etc.
+
+  AMD nomenclature for package is 'Node'.
+
+  Package-related topology information in the kernel:
+
+  - cpuinfo_x86.x86_max_cores:
+
+    The number of cores in a package. This information is retrieved via CPUID.
+
+  - cpuinfo_x86.phys_proc_id:
+
+    The physical ID of the package. This information is retrieved via CPUID
+    and deduced from the APIC IDs of the cores in the package.
+
+  - cpuinfo_x86.logical_id:
+
+    The logical ID of the package. As we do not trust BIOSes to enumerate the
+    packages in a consistent way, we introduced the concept of logical package
+    ID so we can sanely calculate the number of maximum possible packages in
+    the system and have the packages enumerated linearly.
+
+  - topology_max_packages():
+
+    The maximum possible number of packages in the system. Helpful for per
+    package facilities to preallocate per package information.
+
+
+* Cores:
+
+  A core consists of 1 or more threads. It does not matter whether the threads
+  are SMT- or CMT-type threads.
+
+  AMDs nomenclature for a CMT core is "Compute Unit". The kernel always uses
+  "core".
+
+  Core-related topology information in the kernel:
+
+  - smp_num_siblings:
+
+    The number of threads in a core. The number of threads in a package can be
+    calculated by:
+
+    	threads_per_package = cpuinfo_x86.x86_max_cores * smp_num_siblings
+
+
+* Threads:
+
+  A thread is a single scheduling unit. It's the equivalent to a logical Linux
+  CPU.
+
+  AMDs nomenclature for CMT threads is "Compute Unit Core". The kernel always
+  uses "thread".
+
+  Thread-related topology information in the kernel:
+
+  - topology_core_cpumask():
+
+    The cpumask contains all online threads in the package to which a thread
+    belongs.
+
+    The number of online threads is also printed in /proc/cpuinfo "siblings."
+
+  - topology_sibling_mask():
+
+    The cpumask contains all online threads in the core to which a thread
+    belongs.
+
+   - topology_logical_package_id():
+
+    The logical package ID to which a thread belongs.
+
+   - topology_physical_package_id():
+
+    The physical package ID to which a thread belongs.
+
+   - topology_core_id();
+
+    The ID of the core to which a thread belongs. It is also printed in /proc/cpuinfo
+    "core_id."
+
+
+
+System topology examples
+
+Note:
+
+The alternative Linux CPU enumeration depends on how the BIOS enumerates the
+threads. Many BIOSes enumerate all threads 0 first and then all threads 1.
+That has the "advantage" that the logical Linux CPU numbers of threads 0 stay
+the same whether threads are enabled or not. That's merely an implementation
+detail and has no practical impact.
+
+1) Single Package, Single Core
+
+   [package 0] -> [core 0] -> [thread 0] -> Linux CPU 0
+
+2) Single Package, Dual Core
+
+   a) One thread per core
+
+      [package 0] -> [core 0] -> [thread 0] -> Linux CPU 0
+	          -> [core 1] -> [thread 0] -> Linux CPU 1
+
+   b) Two threads per core
+
+      [package 0] -> [core 0] -> [thread 0] -> Linux CPU 0
+   	         	      -> [thread 1] -> Linux CPU 1
+      	          -> [core 1] -> [thread 0] -> Linux CPU 2
+   	         	      -> [thread 1] -> Linux CPU 3
+
+      Alternative enumeration:
+
+      [package 0] -> [core 0] -> [thread 0] -> Linux CPU 0
+   	         	      -> [thread 1] -> Linux CPU 2
+      	          -> [core 1] -> [thread 0] -> Linux CPU 1
+   	         	      -> [thread 1] -> Linux CPU 3
+
+      AMD nomenclature for CMT systems:
+
+      [node 0] -> [Compute Unit 0] -> [Compute Unit Core 0] -> Linux CPU 0
+   	       		           -> [Compute Unit Core 1] -> Linux CPU 1
+               -> [Compute Unit 1] -> [Compute Unit Core 0] -> Linux CPU 2
+   	       		           -> [Compute Unit Core 1] -> Linux CPU 3
+
+4) Dual Package, Dual Core
+
+   a) One thread per core
+
+      [package 0] -> [core 0] -> [thread 0] -> Linux CPU 0
+    	          -> [core 1] -> [thread 0] -> Linux CPU 1
+
+      [package 1] -> [core 0] -> [thread 0] -> Linux CPU 2
+   	          -> [core 1] -> [thread 0] -> Linux CPU 3
+
+   b) Two threads per core
+
+      [package 0] -> [core 0] -> [thread 0] -> Linux CPU 0
+   	           	      -> [thread 1] -> Linux CPU 1
+      	          -> [core 1] -> [thread 0] -> Linux CPU 2
+   	         	      -> [thread 1] -> Linux CPU 3
+
+      [package 1] -> [core 0] -> [thread 0] -> Linux CPU 4
+   	         	      -> [thread 1] -> Linux CPU 5
+      	          -> [core 1] -> [thread 0] -> Linux CPU 6
+   	         	      -> [thread 1] -> Linux CPU 7
+
+      Alternative enumeration:
+
+      [package 0] -> [core 0] -> [thread 0] -> Linux CPU 0
+   	         	      -> [thread 1] -> Linux CPU 4
+       	          -> [core 1] -> [thread 0] -> Linux CPU 1
+   	         	      -> [thread 1] -> Linux CPU 5
+
+      [package 1] -> [core 0] -> [thread 0] -> Linux CPU 2
+   	         	      -> [thread 1] -> Linux CPU 6
+      	          -> [core 1] -> [thread 0] -> Linux CPU 3
+   	         	      -> [thread 1] -> Linux CPU 7
+
+      AMD nomenclature for CMT systems:
+
+      [node 0] -> [Compute Unit 0] -> [Compute Unit Core 0] -> Linux CPU 0
+   	       		           -> [Compute Unit Core 1] -> Linux CPU 1
+               -> [Compute Unit 1] -> [Compute Unit Core 0] -> Linux CPU 2
+   	       		           -> [Compute Unit Core 1] -> Linux CPU 3
+
+      [node 1] -> [Compute Unit 0] -> [Compute Unit Core 0] -> Linux CPU 4
+   	       		           -> [Compute Unit Core 1] -> Linux CPU 5
+               -> [Compute Unit 1] -> [Compute Unit Core 0] -> Linux CPU 6
+   	       		           -> [Compute Unit Core 1] -> Linux CPU 7
+
+