Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/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
This commit is contained in:
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Documentation/x86/topology.txt
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Documentation/x86/topology.txt
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@ -0,0 +1,208 @@
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x86 Topology
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||||
============
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This documents and clarifies the main aspects of x86 topology modelling and
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representation in the kernel. Update/change when doing changes to the
|
||||
respective code.
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||||
The architecture-agnostic topology definitions are in
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Documentation/cputopology.txt. This file holds x86-specific
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differences/specialities which must not necessarily apply to the generic
|
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definitions. Thus, the way to read up on Linux topology on x86 is to start
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with the generic one and look at this one in parallel for the x86 specifics.
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Needless to say, code should use the generic functions - this file is *only*
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here to *document* the inner workings of x86 topology.
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Started by Thomas Gleixner <tglx@linutronix.de> and Borislav Petkov <bp@alien8.de>.
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The main aim of the topology facilities is to present adequate interfaces to
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code which needs to know/query/use the structure of the running system wrt
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threads, cores, packages, etc.
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The kernel does not care about the concept of physical sockets because a
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socket has no relevance to software. It's an electromechanical component. In
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the past a socket always contained a single package (see below), but with the
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advent of Multi Chip Modules (MCM) a socket can hold more than one package. So
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there might be still references to sockets in the code, but they are of
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historical nature and should be cleaned up.
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The topology of a system is described in the units of:
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- packages
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- cores
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- threads
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* Package:
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Packages contain a number of cores plus shared resources, e.g. DRAM
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controller, shared caches etc.
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AMD nomenclature for package is 'Node'.
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Package-related topology information in the kernel:
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- cpuinfo_x86.x86_max_cores:
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The number of cores in a package. This information is retrieved via CPUID.
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|
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- cpuinfo_x86.phys_proc_id:
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|
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The physical ID of the package. This information is retrieved via CPUID
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and deduced from the APIC IDs of the cores in the package.
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|
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- cpuinfo_x86.logical_id:
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The logical ID of the package. As we do not trust BIOSes to enumerate the
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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
|
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the system and have the packages enumerated linearly.
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|
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- topology_max_packages():
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|
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The maximum possible number of packages in the system. Helpful for per
|
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package facilities to preallocate per package information.
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|
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|
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* Cores:
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|
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A core consists of 1 or more threads. It does not matter whether the threads
|
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are SMT- or CMT-type threads.
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|
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AMDs nomenclature for a CMT core is "Compute Unit". The kernel always uses
|
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"core".
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|
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Core-related topology information in the kernel:
|
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|
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- smp_num_siblings:
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|
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The number of threads in a core. The number of threads in a package can be
|
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calculated by:
|
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|
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threads_per_package = cpuinfo_x86.x86_max_cores * smp_num_siblings
|
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|
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|
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* Threads:
|
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|
||||
A thread is a single scheduling unit. It's the equivalent to a logical Linux
|
||||
CPU.
|
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|
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AMDs nomenclature for CMT threads is "Compute Unit Core". The kernel always
|
||||
uses "thread".
|
||||
|
||||
Thread-related topology information in the kernel:
|
||||
|
||||
- topology_core_cpumask():
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|
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The cpumask contains all online threads in the package to which a thread
|
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belongs.
|
||||
|
||||
The number of online threads is also printed in /proc/cpuinfo "siblings."
|
||||
|
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- topology_sibling_mask():
|
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|
||||
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
|
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|
||||
[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
|
|
@ -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));
|
||||
|
|
|
@ -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
|
||||
*/
|
||||
|
|
|
@ -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
|
||||
|
|
|
@ -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;
|
||||
|
|
|
@ -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;
|
||||
|
|
|
@ -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 */
|
||||
|
|
|
@ -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;
|
||||
|
||||
|
|
|
@ -300,7 +300,6 @@ static int nearby_node(int apicid)
|
|||
#ifdef CONFIG_SMP
|
||||
static void amd_get_topology(struct cpuinfo_x86 *c)
|
||||
{
|
||||
u32 cores_per_cu = 1;
|
||||
u8 node_id;
|
||||
int cpu = smp_processor_id();
|
||||
|
||||
|
@ -313,8 +312,8 @@ static void amd_get_topology(struct cpuinfo_x86 *c)
|
|||
|
||||
/* get compute unit information */
|
||||
smp_num_siblings = ((ebx >> 8) & 3) + 1;
|
||||
c->compute_unit_id = ebx & 0xff;
|
||||
cores_per_cu += ((ebx >> 8) & 3);
|
||||
c->x86_max_cores /= smp_num_siblings;
|
||||
c->cpu_core_id = ebx & 0xff;
|
||||
} else if (cpu_has(c, X86_FEATURE_NODEID_MSR)) {
|
||||
u64 value;
|
||||
|
||||
|
@ -325,19 +324,16 @@ static void amd_get_topology(struct cpuinfo_x86 *c)
|
|||
|
||||
/* fixup multi-node processor information */
|
||||
if (nodes_per_socket > 1) {
|
||||
u32 cores_per_node;
|
||||
u32 cus_per_node;
|
||||
|
||||
set_cpu_cap(c, X86_FEATURE_AMD_DCM);
|
||||
cores_per_node = c->x86_max_cores / nodes_per_socket;
|
||||
cus_per_node = cores_per_node / cores_per_cu;
|
||||
cus_per_node = c->x86_max_cores / nodes_per_socket;
|
||||
|
||||
/* store NodeID, use llc_shared_map to store sibling info */
|
||||
per_cpu(cpu_llc_id, cpu) = node_id;
|
||||
|
||||
/* core id has to be in the [0 .. cores_per_node - 1] range */
|
||||
c->cpu_core_id %= cores_per_node;
|
||||
c->compute_unit_id %= cus_per_node;
|
||||
c->cpu_core_id %= cus_per_node;
|
||||
}
|
||||
}
|
||||
#endif
|
||||
|
|
|
@ -18,4 +18,6 @@ const char *const x86_power_flags[32] = {
|
|||
"", /* tsc invariant mapped to constant_tsc */
|
||||
"cpb", /* core performance boost */
|
||||
"eff_freq_ro", /* Readonly aperf/mperf */
|
||||
"proc_feedback", /* processor feedback interface */
|
||||
"acc_power", /* accumulated power mechanism */
|
||||
};
|
||||
|
|
|
@ -422,7 +422,7 @@ static bool match_smt(struct cpuinfo_x86 *c, struct cpuinfo_x86 *o)
|
|||
|
||||
if (c->phys_proc_id == o->phys_proc_id &&
|
||||
per_cpu(cpu_llc_id, cpu1) == per_cpu(cpu_llc_id, cpu2) &&
|
||||
c->compute_unit_id == o->compute_unit_id)
|
||||
c->cpu_core_id == o->cpu_core_id)
|
||||
return topology_sane(c, o, "smt");
|
||||
|
||||
} else if (c->phys_proc_id == o->phys_proc_id &&
|
||||
|
|
|
@ -20,6 +20,7 @@
|
|||
#include <linux/pci.h>
|
||||
|
||||
#include <asm/mce.h>
|
||||
#include <asm/smp.h>
|
||||
#include <asm/amd_nb.h>
|
||||
#include <asm/irq_vectors.h>
|
||||
|
||||
|
@ -206,7 +207,7 @@ static u32 get_nbc_for_node(int node_id)
|
|||
struct cpuinfo_x86 *c = &boot_cpu_data;
|
||||
u32 cores_per_node;
|
||||
|
||||
cores_per_node = c->x86_max_cores / amd_get_nodes_per_socket();
|
||||
cores_per_node = (c->x86_max_cores * smp_num_siblings) / amd_get_nodes_per_socket();
|
||||
|
||||
return cores_per_node * node_id;
|
||||
}
|
||||
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Reference in New Issue
Block a user