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x86/cpu/topology: Use a data structure for topology info

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Put the processor accounting into a data structure, which will gain more
topology related information in the next steps, and sanitize the accounting.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20240213210252.111451909@linutronix.de
This commit is contained in:
Thomas Gleixner 2024-02-13 22:05:49 +01:00
parent 4c4c6f3870
commit 72530464ed
1 changed files with 29 additions and 30 deletions
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59
arch/x86/kernel/cpu/topology.c
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@ -22,6 +22,18 @@ DECLARE_BITMAP(phys_cpu_present_map, MAX_LOCAL_APIC) __read_mostly;
/* Used for CPU number allocation and parallel CPU bringup */
u32 cpuid_to_apicid[] __read_mostly = { [0 ... NR_CPUS - 1] = BAD_APICID, };
/*
* Keep track of assigned, disabled and rejected CPUs. Present assigned
* with 1 as CPU #0 is reserved for the boot CPU.
*/
static struct {
unsigned int nr_assigned_cpus;
unsigned int nr_disabled_cpus;
unsigned int nr_rejected_cpus;
} topo_info __read_mostly = {
.nr_assigned_cpus = 1,
};
/*
* Processor to be disabled specified by kernel parameter
* disable_cpu_apicid=<int>, mostly used for the kdump 2nd kernel to
@ -29,19 +41,6 @@ u32 cpuid_to_apicid[] __read_mostly = { [0 ... NR_CPUS - 1] = BAD_APICID, };
*/
static u32 disabled_cpu_apicid __ro_after_init = BAD_APICID;
static unsigned int num_processors;
static unsigned int disabled_cpus;
/*
* The number of allocated logical CPU IDs. Since logical CPU IDs are allocated
* contiguously, it equals to current allocated max logical CPU ID plus 1.
* All allocated CPU IDs should be in the [0, nr_logical_cpuids) range,
* so the maximum of nr_logical_cpuids is nr_cpu_ids.
*
* NOTE: Reserve 0 for BSP.
*/
static int nr_logical_cpuids = 1;
bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
{
return phys_id == (u64)cpuid_to_apicid[cpu];
@ -75,7 +74,7 @@ static int __init smp_init_primary_thread_mask(void)
return 0;
}
for (cpu = 0; cpu < nr_logical_cpuids; cpu++)
for (cpu = 0; cpu < topo_info.nr_assigned_cpus; cpu++)
cpu_mark_primary_thread(cpu, cpuid_to_apicid[cpu]);
return 0;
}
@ -89,7 +88,7 @@ static int topo_lookup_cpuid(u32 apic_id)
int i;
/* CPU# to APICID mapping is persistent once it is established */
for (i = 0; i < nr_logical_cpuids; i++) {
for (i = 0; i < topo_info.nr_assigned_cpus; i++) {
if (cpuid_to_apicid[i] == apic_id)
return i;
}
@ -107,22 +106,21 @@ static int allocate_logical_cpuid(u32 apic_id)
if (cpu >= 0)
return cpu;
cpuid_to_apicid[nr_logical_cpuids] = apic_id;
return nr_logical_cpuids++;
return topo_info.nr_assigned_cpus++;
}
static void cpu_update_apic(int cpu, u32 apicid)
static void cpu_update_apic(unsigned int cpu, u32 apic_id)
{
#if defined(CONFIG_SMP) || defined(CONFIG_X86_64)
early_per_cpu(x86_cpu_to_apicid, cpu) = apicid;
early_per_cpu(x86_cpu_to_apicid, cpu) = apic_id;
#endif
cpuid_to_apicid[cpu] = apic_id;
set_cpu_possible(cpu, true);
set_bit(apicid, phys_cpu_present_map);
set_bit(apic_id, phys_cpu_present_map);
set_cpu_present(cpu, true);
num_processors++;
if (system_state != SYSTEM_BOOTING)
cpu_mark_primary_thread(cpu, apicid);
cpu_mark_primary_thread(cpu, apic_id);
}
static int generic_processor_info(int apicid)
@ -137,18 +135,18 @@ static int generic_processor_info(int apicid)
return 0;
if (disabled_cpu_apicid == apicid) {
int thiscpu = num_processors + disabled_cpus;
int thiscpu = topo_info.nr_assigned_cpus + topo_info.nr_disabled_cpus;
pr_warn("APIC: Disabling requested cpu. Processor %d/0x%x ignored.\n",
thiscpu, apicid);
disabled_cpus++;
topo_info.nr_rejected_cpus++;
return -ENODEV;
}
if (num_processors >= nr_cpu_ids) {
if (topo_info.nr_assigned_cpus >= nr_cpu_ids) {
pr_warn_once("APIC: CPU limit of %d reached. Ignoring further CPUs\n", nr_cpu_ids);
disabled_cpus++;
topo_info.nr_rejected_cpus++;
return -ENOSPC;
}
@ -178,14 +176,16 @@ static int __initdata setup_possible_cpus = -1;
*/
__init void prefill_possible_map(void)
{
unsigned int num_processors = topo_info.nr_assigned_cpus;
unsigned int disabled_cpus = topo_info.nr_disabled_cpus;
int i, possible;
i = setup_max_cpus ?: 1;
if (setup_possible_cpus == -1) {
possible = num_processors;
possible = topo_info.nr_assigned_cpus;
#ifdef CONFIG_HOTPLUG_CPU
if (setup_max_cpus)
possible += disabled_cpus;
possible += num_processors;
#else
if (possible > i)
possible = i;
@ -238,7 +238,7 @@ void __init topology_register_apic(u32 apic_id, u32 acpi_id, bool present)
}
if (!present) {
disabled_cpus++;
topo_info.nr_disabled_cpus++;
return;
}
@ -295,7 +295,6 @@ void topology_hotunplug_apic(unsigned int cpu)
per_cpu(x86_cpu_to_apicid, cpu) = BAD_APICID;
clear_bit(apic_id, phys_cpu_present_map);
set_cpu_present(cpu, false);
num_processors--;
}
#endif