* [PATCH 4.8 105/140] x86/boot/smp: Dont try to poke disabled/non-existent APIC
[not found] <20161026122220.384323763@linuxfoundation.org>
@ 2016-10-26 12:22 ` Greg Kroah-Hartman
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From: Greg Kroah-Hartman @ 2016-10-26 12:22 UTC (permalink / raw)
To: linux-kernel
Cc: Peter Zijlstra, H. Peter Anvin, Jiri Olsa, Ingo Molnar,
Ville Syrjälä, Prarit Bhargava, Borislav Petkov, dyoung,
Len Brown, Denys Vlasenko, Brian Gerst, Borislav Petkov,
Andy Lutomirski, Josh Poimboeuf, Thomas Gleixner, Yinghai Lu,
Juergen Gross, Greg Kroah-Hartman, kexec, stable, Eric Biederman,
Linus Torvalds
4.8-stable review patch. If anyone has any objections, please let me know.
------------------
From: Ville Syrjälä <ville.syrjala@linux.intel.com>
commit ff8560512b8d4b7ca3ef4fd69166634ac30b2525 upstream.
Apparently trying to poke a disabled or non-existent APIC
leads to a box that doesn't even boot. Let's not do that.
No real clue if this is the right fix, but at least my
P3 machine boots again.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: dyoung@redhat.com
Cc: kexec@lists.infradead.org
Fixes: 2a51fe083eba ("arch/x86: Handle non enumerated CPU after physical hotplug")
Link: http://lkml.kernel.org/r/1477102684-5092-1-git-send-email-ville.syrjala@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/kernel/smpboot.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1408,15 +1408,17 @@ __init void prefill_possible_map(void)
/* No boot processor was found in mptable or ACPI MADT */
if (!num_processors) {
- int apicid = boot_cpu_physical_apicid;
- int cpu = hard_smp_processor_id();
+ if (boot_cpu_has(X86_FEATURE_APIC)) {
+ int apicid = boot_cpu_physical_apicid;
+ int cpu = hard_smp_processor_id();
- pr_warn("Boot CPU (id %d) not listed by BIOS\n", cpu);
+ pr_warn("Boot CPU (id %d) not listed by BIOS\n", cpu);
- /* Make sure boot cpu is enumerated */
- if (apic->cpu_present_to_apicid(0) == BAD_APICID &&
- apic->apic_id_valid(apicid))
- generic_processor_info(apicid, boot_cpu_apic_version);
+ /* Make sure boot cpu is enumerated */
+ if (apic->cpu_present_to_apicid(0) == BAD_APICID &&
+ apic->apic_id_valid(apicid))
+ generic_processor_info(apicid, boot_cpu_apic_version);
+ }
if (!num_processors)
num_processors = 1;
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