[tip:x86/apic] x86: apic: Fixmap apic address even if apic disabled

tip-bot for Cyrill Gorcunov
2009-05-11T13:55:41Z

Commit-ID: cec6be6d1069d697beb490bbb40a290d5ff554a2
Gitweb: http://git.kernel.org/tip/cec6be6d1069d697beb490bbb40a290d5ff554a2
Author: Cyrill Gorcunov <gorcunov@gmail.com>
AuthorDate: Mon, 11 May 2009 17:41:40 +0400
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Mon, 11 May 2009 15:50:58 +0200

x86: apic: Fixmap apic address even if apic disabled

In case if apic were disabled by boot option
we still need read_apic operation. So fixmap
a fake apic area if needed.

[ Impact: fix boot crash ]

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: yinghai@kernel.org
Cc: eswierk@aristanetworks.com
LKML-Reference: <20090511134140.GH4624@lenovo>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

---
arch/x86/kernel/apic/apic.c | 17 +++++++++--------
1 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 0e6543f..07cffc1 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1587,13 +1587,6 @@ void __init init_apic_mappings(void)
} else
apic_phys = mp_lapic_addr;

- /* lets check if we may NOP'ify apic operations */
- if (!cpu_has_apic) {
- pr_info("APIC: disable apic facility\n");
- apic_disable();
- return;
- }
-
/*
* acpi lapic path already maps that address in
* acpi_register_lapic_address()
@@ -1602,7 +1595,15 @@ void __init init_apic_mappings(void)
set_fixmap_nocache(FIX_APIC_BASE, apic_phys);

apic_printk(APIC_VERBOSE, "mapped APIC to %08lx (%08lx)\n",
- APIC_BASE, apic_phys);
+ APIC_BASE, apic_phys);
+
+ /* lets check if we may NOP'ify apic operations */
+ if (!cpu_has_apic) {
+ pr_info("APIC: disable apic facility\n");
+ apic_disable();
+ return;
+ }
+
/*
* Fetch the APIC ID of the BSP in case we have a
* default configuration (or the MP table is broken).