diff options
| author | Roman Kisel <romank@linux.microsoft.com> | 2025-05-07 11:22:26 -0700 |
|---|---|---|
| committer | Wei Liu <wei.liu@kernel.org> | 2025-05-23 16:30:56 +0000 |
| commit | 43cb39ad260a168abf6da3a48f394afff92d436b (patch) | |
| tree | 0f6d3729bc472fc2958f7bd6d9d856f1a4990681 /arch/x86/kernel/smpboot.c | |
| parent | 86c48271e0d60c82665e9fd61277002391efcef7 (diff) | |
arch/x86: Provide the CPU number in the wakeup AP callback
When starting APs, confidential guests and paravisor guests
need to know the CPU number, and the pattern of using the linear
search has emerged in several places. With N processors that leads
to the O(N^2) time complexity.
Provide the CPU number in the AP wake up callback so that one can
get the CPU number in constant time.
Suggested-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: Roman Kisel <romank@linux.microsoft.com>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20250507182227.7421-3-romank@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20250507182227.7421-3-romank@linux.microsoft.com>
Diffstat (limited to 'arch/x86/kernel/smpboot.c')
| -rw-r--r-- | arch/x86/kernel/smpboot.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index d6cf1e23c2a3..d52e9238e9fd 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -695,7 +695,7 @@ static void send_init_sequence(u32 phys_apicid) /* * Wake up AP by INIT, INIT, STARTUP sequence. */ -static int wakeup_secondary_cpu_via_init(u32 phys_apicid, unsigned long start_eip) +static int wakeup_secondary_cpu_via_init(u32 phys_apicid, unsigned long start_eip, unsigned int cpu) { unsigned long send_status = 0, accept_status = 0; int num_starts, j, maxlvt; @@ -842,7 +842,7 @@ int common_cpu_up(unsigned int cpu, struct task_struct *idle) * Returns zero if startup was successfully sent, else error code from * ->wakeup_secondary_cpu. */ -static int do_boot_cpu(u32 apicid, int cpu, struct task_struct *idle) +static int do_boot_cpu(u32 apicid, unsigned int cpu, struct task_struct *idle) { unsigned long start_ip = real_mode_header->trampoline_start; int ret; @@ -896,11 +896,11 @@ static int do_boot_cpu(u32 apicid, int cpu, struct task_struct *idle) * - Use an INIT boot APIC message */ if (apic->wakeup_secondary_cpu_64) - ret = apic->wakeup_secondary_cpu_64(apicid, start_ip); + ret = apic->wakeup_secondary_cpu_64(apicid, start_ip, cpu); else if (apic->wakeup_secondary_cpu) - ret = apic->wakeup_secondary_cpu(apicid, start_ip); + ret = apic->wakeup_secondary_cpu(apicid, start_ip, cpu); else - ret = wakeup_secondary_cpu_via_init(apicid, start_ip); + ret = wakeup_secondary_cpu_via_init(apicid, start_ip, cpu); /* If the wakeup mechanism failed, cleanup the warm reset vector */ if (ret) |