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Message-ID: <tip-8f54969dc8d6704632b42cbb5e47730cd75cc713@git.kernel.org>
Date: Thu, 22 Sep 2016 12:10:52 -0700
From: tip-bot for Gu Zheng <tipbot@...or.com>
To: linux-tip-commits@...r.kernel.org
Cc: tangchen@...fujitsu.com, linux-kernel@...r.kernel.org,
guz.fnst@...fujitsu.com, douly.fnst@...fujitsu.com,
mingo@...nel.org, zhugh.fnst@...fujitsu.com, hpa@...or.com,
tglx@...utronix.de
Subject: [tip:x86/apic] x86/acpi: Introduce persistent storage for cpuid <->
apicid mapping
Commit-ID: 8f54969dc8d6704632b42cbb5e47730cd75cc713
Gitweb: http://git.kernel.org/tip/8f54969dc8d6704632b42cbb5e47730cd75cc713
Author: Gu Zheng <guz.fnst@...fujitsu.com>
AuthorDate: Thu, 25 Aug 2016 16:35:16 +0800
Committer: Thomas Gleixner <tglx@...utronix.de>
CommitDate: Wed, 21 Sep 2016 21:18:38 +0200
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@...fujitsu.com>
Signed-off-by: Tang Chen <tangchen@...fujitsu.com>
Signed-off-by: Zhu Guihua <zhugh.fnst@...fujitsu.com>
Signed-off-by: Dou Liyang <douly.fnst@...fujitsu.com>
Acked-by: Ingo Molnar <mingo@...nel.org>
Cc: mika.j.penttila@...il.com
Cc: len.brown@...el.com
Cc: rafael@...nel.org
Cc: rjw@...ysocki.net
Cc: yasu.isimatu@...il.com
Cc: linux-mm@...ck.org
Cc: linux-acpi@...r.kernel.org
Cc: isimatu.yasuaki@...fujitsu.com
Cc: gongzhaogang@...pur.com
Cc: tj@...nel.org
Cc: izumi.taku@...fujitsu.com
Cc: cl@...ux.com
Cc: chen.tang@...ystack.cn
Cc: akpm@...ux-foundation.org
Cc: kamezawa.hiroyu@...fujitsu.com
Cc: lenb@...nel.org
Link: http://lkml.kernel.org/r/1472114120-3281-4-git-send-email-douly.fnst@cn.fujitsu.com
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
---
arch/x86/include/asm/mpspec.h | 1 +
arch/x86/kernel/acpi/boot.c | 7 +----
arch/x86/kernel/apic/apic.c | 60 ++++++++++++++++++++++++++++++++++++++++---
3 files changed, 59 insertions(+), 9 deletions(-)
diff --git a/arch/x86/include/asm/mpspec.h b/arch/x86/include/asm/mpspec.h
index c2f94dc..3200704 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 0447e31..7d668d1 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 a8c94bb..2dc01c3 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
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