From: Gu Zheng <guz.fnst@xxxxxxxxxxxxxx>
This patch finishes step2 mentioned in previous patch 4.
In this patch, we introduce a new static array named apicid_to_cpuid[],
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 apicid_to_cpuid[], 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@xxxxxxxxxxxxxx>
Signed-off-by: Tang Chen <tangchen@xxxxxxxxxxxxxx>
---
arch/x86/include/asm/mpspec.h | 1 +
arch/x86/kernel/acpi/boot.c | 6 ++---
arch/x86/kernel/apic/apic.c | 53 ++++++++++++++++++++++++++++++++++++++++---
3 files changed, 53 insertions(+), 7 deletions(-)
diff --git a/arch/x86/include/asm/mpspec.h b/arch/x86/include/asm/mpspec.h
index b07233b..db902d8 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 e49ee24..bcc85b2 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -174,15 +174,13 @@ static int acpi_register_lapic(int id, u8 enabled)
return -EINVAL;
}
- if (!enabled) {
+ if (!enabled)
++disabled_cpus;
- return -EINVAL;
- }
if (boot_cpu_physical_apicid != -1U)
ver = apic_version[boot_cpu_physical_apicid];
- return generic_processor_info(id, ver);
+ return __generic_processor_info(id, ver, enabled);
}
static int __init
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index a9c9830..42b2a9c 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1977,7 +1977,45 @@ void disconnect_bsp_APIC(int virt_wire_setup)
apic_write(APIC_LVT1, value);
}
-static int __generic_processor_info(int apicid, int version, bool enabled)
+/*
+ * Current allocated max logical CPU ID plus 1.
+ * All allocated CPU ID should be in [0, max_logical_cpuid),
+ * so the maximum of max_logical_cpuid is nr_cpu_ids.
+ *
+ * NOTE: Reserve 0 for BSP.
+ */
+static int max_logical_cpuid = 1;
+
+static int cpuid_to_apicid[] = {
+ [0 ... NR_CPUS - 1] = -1,
+};
+
+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 < max_logical_cpuid; i++) {
+ if (cpuid_to_apicid[i] == apicid)
+ return i;
+ }
+
+ /* Allocate a new cpuid. */
+ if (max_logical_cpuid >= nr_cpu_ids) {
+ WARN_ONCE(1, "Only %d processors supported."
+ "Processor %d/0x%x and the rest are ignored.\n",
+ nr_cpu_ids - 1, max_logical_cpuid, apicid);
+ return -1;
+ }
+
+ cpuid_to_apicid[max_logical_cpuid] = apicid;
+ return max_logical_cpuid++;
+}
+
+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,
@@ -2058,8 +2096,17 @@ 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) {
+ if (enabled)
+ disabled_cpus++;
+ return -EINVAL;
+ }
+ }
/*
* Validate version
--
1.9.3
--
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