Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/l…

…inux/kernel/git/tip/tip

Pull x86 fixes from Thomas Gleixner:
 "This lot contains:

   - Some fixups for the fallout of the topology consolidation which
     unearthed AMD/Intel inconsistencies
   - Documentation for the x86 topology management
   - Support for AMD advanced power management bits
   - Two simple cleanups removing duplicated code"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu: Add advanced power management bits
  x86/thread_info: Merge two !__ASSEMBLY__ sections
  x86/cpufreq: Remove duplicated TDP MSR macro definitions
  x86/Documentation: Start documenting x86 topology
  x86/cpu: Get rid of compute_unit_id
  perf/x86/amd: Cleanup Fam10h NB event constraints
  x86/topology: Fix AMD core count

Documentation/x86/topology.txt

@@ -0,0 +1,208 @@
+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

arch/x86/events/amd/core.c

@@ -369,7 +369,7 @@ static int amd_pmu_cpu_prepare(int cpu)
 
 	WARN_ON_ONCE(cpuc->amd_nb);
 
-	if (boot_cpu_data.x86_max_cores < 2)
+	if (!x86_pmu.amd_nb_constraints)
 		return NOTIFY_OK;
 
 	cpuc->amd_nb = amd_alloc_nb(cpu);
@@ -388,7 +388,7 @@ static void amd_pmu_cpu_starting(int cpu)
 
 	cpuc->perf_ctr_virt_mask = AMD64_EVENTSEL_HOSTONLY;
 
-	if (boot_cpu_data.x86_max_cores < 2)
+	if (!x86_pmu.amd_nb_constraints)
 		return;
 
 	nb_id = amd_get_nb_id(cpu);
@@ -414,7 +414,7 @@ static void amd_pmu_cpu_dead(int cpu)
 {
 	struct cpu_hw_events *cpuhw;
 
-	if (boot_cpu_data.x86_max_cores < 2)
+	if (!x86_pmu.amd_nb_constraints)
 		return;
 
 	cpuhw = &per_cpu(cpu_hw_events, cpu);
@@ -648,6 +648,8 @@ static __initconst const struct x86_pmu amd_pmu = {
 	.cpu_prepare		= amd_pmu_cpu_prepare,
 	.cpu_starting		= amd_pmu_cpu_starting,
 	.cpu_dead		= amd_pmu_cpu_dead,
+
+	.amd_nb_constraints	= 1,
 };
 
 static int __init amd_core_pmu_init(void)
@@ -674,6 +676,11 @@ static int __init amd_core_pmu_init(void)
 	x86_pmu.eventsel	= MSR_F15H_PERF_CTL;
 	x86_pmu.perfctr		= MSR_F15H_PERF_CTR;
 	x86_pmu.num_counters	= AMD64_NUM_COUNTERS_CORE;
+	/*
+	 * AMD Core perfctr has separate MSRs for the NB events, see
+	 * the amd/uncore.c driver.
+	 */
+	x86_pmu.amd_nb_constraints = 0;
 
 	pr_cont("core perfctr, ");
 	return 0;
@@ -693,6 +700,14 @@ __init int amd_pmu_init(void)
 	if (ret)
 		return ret;
 
+	if (num_possible_cpus() == 1) {
+		/*
+		 * No point in allocating data structures to serialize
+		 * against other CPUs, when there is only the one CPU.
+		 */
+		x86_pmu.amd_nb_constraints = 0;
+	}
+
 	/* Events are common for all AMDs */
 	memcpy(hw_cache_event_ids, amd_hw_cache_event_ids,
 	       sizeof(hw_cache_event_ids));

arch/x86/events/perf_event.h

@@ -607,6 +607,11 @@ struct x86_pmu {
 	 */
 	atomic_t	lbr_exclusive[x86_lbr_exclusive_max];
 
+	/*
+	 * AMD bits
+	 */
+	unsigned int	amd_nb_constraints : 1;
+
 	/*
 	 * Extra registers for events
 	 */

arch/x86/include/asm/msr-index.h

@@ -190,6 +190,7 @@
 #define MSR_PP1_ENERGY_STATUS		0x00000641
 #define MSR_PP1_POLICY			0x00000642
 
+/* Config TDP MSRs */
 #define MSR_CONFIG_TDP_NOMINAL		0x00000648
 #define MSR_CONFIG_TDP_LEVEL_1		0x00000649
 #define MSR_CONFIG_TDP_LEVEL_2		0x0000064A
@@ -210,13 +211,6 @@
 #define MSR_GFX_PERF_LIMIT_REASONS	0x000006B0
 #define MSR_RING_PERF_LIMIT_REASONS	0x000006B1
 
-/* Config TDP MSRs */
-#define MSR_CONFIG_TDP_NOMINAL		0x00000648
-#define MSR_CONFIG_TDP_LEVEL1		0x00000649
-#define MSR_CONFIG_TDP_LEVEL2		0x0000064A
-#define MSR_CONFIG_TDP_CONTROL		0x0000064B
-#define MSR_TURBO_ACTIVATION_RATIO	0x0000064C
-
 /* Hardware P state interface */
 #define MSR_PPERF			0x0000064e
 #define MSR_PERF_LIMIT_REASONS		0x0000064f

arch/x86/include/asm/processor.h

@@ -132,8 +132,6 @@ struct cpuinfo_x86 {
 	u16			logical_proc_id;
 	/* Core id: */
 	u16			cpu_core_id;
-	/* Compute unit id */
-	u8			compute_unit_id;
 	/* Index into per_cpu list: */
 	u16			cpu_index;
 	u32			microcode;

arch/x86/include/asm/smp.h

@@ -155,6 +155,7 @@ static inline int wbinvd_on_all_cpus(void)
 	wbinvd();
 	return 0;
 }
+#define smp_num_siblings	1
 #endif /* CONFIG_SMP */
 
 extern unsigned disabled_cpus;

arch/x86/include/asm/thread_info.h

@@ -276,11 +276,9 @@ static inline bool is_ia32_task(void)
  */
 #define force_iret() set_thread_flag(TIF_NOTIFY_RESUME)
 
-#endif	/* !__ASSEMBLY__ */
-
-#ifndef __ASSEMBLY__
 extern void arch_task_cache_init(void);
 extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
 extern void arch_release_task_struct(struct task_struct *tsk);
-#endif
+#endif	/* !__ASSEMBLY__ */
+
 #endif /* _ASM_X86_THREAD_INFO_H */

arch/x86/kernel/amd_nb.c

@@ -170,15 +170,13 @@ int amd_get_subcaches(int cpu)
 {
 	struct pci_dev *link = node_to_amd_nb(amd_get_nb_id(cpu))->link;
 	unsigned int mask;
-	int cuid;
 
 	if (!amd_nb_has_feature(AMD_NB_L3_PARTITIONING))
 		return 0;
 
 	pci_read_config_dword(link, 0x1d4, &mask);
 
-	cuid = cpu_data(cpu).compute_unit_id;
-	return (mask >> (4 * cuid)) & 0xf;
+	return (mask >> (4 * cpu_data(cpu).cpu_core_id)) & 0xf;
 }
 
 int amd_set_subcaches(int cpu, unsigned long mask)
@@ -204,7 +202,7 @@ int amd_set_subcaches(int cpu, unsigned long mask)
 		pci_write_config_dword(nb->misc, 0x1b8, reg & ~0x180000);
 	}
 
-	cuid = cpu_data(cpu).compute_unit_id;
+	cuid = cpu_data(cpu).cpu_core_id;
 	mask <<= 4 * cuid;
 	mask |= (0xf ^ (1 << cuid)) << 26;