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authorGu Zheng <guz.fnst@cn.fujitsu.com>2016-08-25 11:35:16 +0300
committerThomas Gleixner <tglx@linutronix.de>2016-09-21 22:18:38 +0300
commit8f54969dc8d6704632b42cbb5e47730cd75cc713 (patch)
tree62703aca9b29687c588ba285ace9fd3f2cd70781
parentf7c28833c252031bc68a29e26a18a661797cf3a3 (diff)
downloadlinux-8f54969dc8d6704632b42cbb5e47730cd75cc713.tar.xz
x86/acpi: Introduce persistent storage for cpuid <-> apicid mapping
The whole patch-set aims at making cpuid <-> nodeid mapping persistent. So that, when node online/offline happens, cache based on cpuid <-> nodeid mapping such as wq_numa_possible_cpumask will not cause any problem. It contains 4 steps: 1. Enable apic registeration flow to handle both enabled and disabled cpus. 2. Introduce a new array storing all possible cpuid <-> apicid mapping. 3. Enable _MAT and MADT relative apis to return non-present or disabled cpus' apicid. 4. Establish all possible cpuid <-> nodeid mapping. This patch finishes step 2. In this patch, we introduce a new static array named cpuid_to_apicid[], which is large enough to store info for all possible cpus. And then, we modify the cpuid calculation. In generic_processor_info(), it simply finds the next unused cpuid. And it is also why the cpuid <-> nodeid mapping changes with node hotplug. After this patch, we find the next unused cpuid, map it to an apicid, and store the mapping in cpuid_to_apicid[], so that cpuid <-> apicid mapping will be persistent. And finally we will use this array to make cpuid <-> nodeid persistent. cpuid <-> apicid mapping is established at local apic registeration time. But non-present or disabled cpus are ignored. In this patch, we establish all possible cpuid <-> apicid mapping when registering local apic. Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com> Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Signed-off-by: Zhu Guihua <zhugh.fnst@cn.fujitsu.com> Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: mika.j.penttila@gmail.com Cc: len.brown@intel.com Cc: rafael@kernel.org Cc: rjw@rjwysocki.net Cc: yasu.isimatu@gmail.com Cc: linux-mm@kvack.org Cc: linux-acpi@vger.kernel.org Cc: isimatu.yasuaki@jp.fujitsu.com Cc: gongzhaogang@inspur.com Cc: tj@kernel.org Cc: izumi.taku@jp.fujitsu.com Cc: cl@linux.com Cc: chen.tang@easystack.cn Cc: akpm@linux-foundation.org Cc: kamezawa.hiroyu@jp.fujitsu.com Cc: lenb@kernel.org Link: http://lkml.kernel.org/r/1472114120-3281-4-git-send-email-douly.fnst@cn.fujitsu.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
-rw-r--r--arch/x86/include/asm/mpspec.h1
-rw-r--r--arch/x86/kernel/acpi/boot.c7
-rw-r--r--arch/x86/kernel/apic/apic.c60
3 files changed, 59 insertions, 9 deletions
diff --git a/arch/x86/include/asm/mpspec.h b/arch/x86/include/asm/mpspec.h
index c2f94dcc92ce..32007041ef8c 100644
--- a/arch/x86/include/asm/mpspec.h
+++ b/arch/x86/include/asm/mpspec.h
@@ -86,6 +86,7 @@ static inline void early_reserve_e820_mpc_new(void) { }
#endif
int generic_processor_info(int apicid, int version);
+int __generic_processor_info(int apicid, int version, bool enabled);
#define PHYSID_ARRAY_SIZE BITS_TO_LONGS(MAX_LOCAL_APIC)
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 0447e314e7f5..7d668d172fce 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -176,15 +176,10 @@ static int acpi_register_lapic(int id, u32 acpiid, u8 enabled)
return -EINVAL;
}
- if (!enabled) {
- ++disabled_cpus;
- return -EINVAL;
- }
-
if (boot_cpu_physical_apicid != -1U)
ver = boot_cpu_apic_version;
- cpu = generic_processor_info(id, ver);
+ cpu = __generic_processor_info(id, ver, enabled);
if (cpu >= 0)
early_per_cpu(x86_cpu_to_acpiid, cpu) = acpiid;
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index a8c94bb6b528..2dc01c38ad8e 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -2021,7 +2021,53 @@ void disconnect_bsp_APIC(int virt_wire_setup)
apic_write(APIC_LVT1, value);
}
-static int __generic_processor_info(int apicid, int version, bool enabled)
+/*
+ * 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 ID should be in [0, nr_logical_cpuidi), so the maximum of
+ * nr_logical_cpuids is nr_cpu_ids.
+ *
+ * NOTE: Reserve 0 for BSP.
+ */
+static int nr_logical_cpuids = 1;
+
+/*
+ * Used to store mapping between logical CPU IDs and APIC IDs.
+ */
+static int cpuid_to_apicid[] = {
+ [0 ... NR_CPUS - 1] = -1,
+};
+
+/*
+ * Should use this API to allocate logical CPU IDs to keep nr_logical_cpuids
+ * and cpuid_to_apicid[] synchronized.
+ */
+static int allocate_logical_cpuid(int apicid)
+{
+ int i;
+
+ /*
+ * cpuid <-> apicid mapping is persistent, so when a cpu is up,
+ * check if the kernel has allocated a cpuid for it.
+ */
+ for (i = 0; i < nr_logical_cpuids; i++) {
+ if (cpuid_to_apicid[i] == apicid)
+ return i;
+ }
+
+ /* Allocate a new cpuid. */
+ if (nr_logical_cpuids >= nr_cpu_ids) {
+ WARN_ONCE(1, "Only %d processors supported."
+ "Processor %d/0x%x and the rest are ignored.\n",
+ nr_cpu_ids - 1, nr_logical_cpuids, apicid);
+ return -1;
+ }
+
+ cpuid_to_apicid[nr_logical_cpuids] = apicid;
+ return nr_logical_cpuids++;
+}
+
+int __generic_processor_info(int apicid, int version, bool enabled)
{
int cpu, max = nr_cpu_ids;
bool boot_cpu_detected = physid_isset(boot_cpu_physical_apicid,
@@ -2096,8 +2142,16 @@ static int __generic_processor_info(int apicid, int version, bool enabled)
* for BSP.
*/
cpu = 0;
- } else
- cpu = cpumask_next_zero(-1, cpu_present_mask);
+
+ /* Logical cpuid 0 is reserved for BSP. */
+ cpuid_to_apicid[0] = apicid;
+ } else {
+ cpu = allocate_logical_cpuid(apicid);
+ if (cpu < 0) {
+ disabled_cpus++;
+ return -EINVAL;
+ }
+ }
/*
* This can happen on physical hotplug. The sanity check at boot time