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authorYinghai Lu <yinghai@kernel.org>2009-05-02 10:40:57 -0700
committerIngo Molnar <mingo@elte.hu>2009-05-12 12:22:06 +0200
commit4797f6b021a3fa399942245d07a1feb30df81bb8 (patch)
treeaea4f0aec80786f8e5b4d55c9140add997a9a348 /arch
parent6cda3eb62ef42aa5acd649bf99c8db544e0f4051 (diff)
x86: read apic ID in the !acpi_lapic case
Ed found that on 32-bit, boot_cpu_physical_apicid is not read right, when the mptable is broken. Interestingly, actually three paths use/set it: 1. acpi: at that time that is already read from reg 2. mptable: only read from mptable 3. no madt, and no mptable, that use default apic id 0 for 64-bit, -1 for 32-bit so we could read the apic id for the 2/3 path. We trust the hardware register more than we trust a BIOS data structure (the mptable). We can also avoid the double set_fixmap() when acpi_lapic is used, and also need to move cpu_has_apic earlier and call apic_disable(). Also when need to update the apic id, we'd better read and set the apic version as well - so that quirks are applied precisely. v2: make path 3 with 64bit, use -1 as apic id, so could read it later. v3: fix whitespace problem pointed out by Ed Swierk v5: fix boot crash [ Impact: get correct apic id for bsp other than acpi path ] Reported-by: Ed Swierk <eswierk@aristanetworks.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> LKML-Reference: <49FC85A9.2070702@kernel.org> [ v4: sanity-check in the ACPI case too ] Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/include/asm/smp.h2
-rw-r--r--arch/x86/kernel/apic/apic.c46
-rw-r--r--arch/x86/kernel/apic/io_apic.c5
3 files changed, 28 insertions, 25 deletions
diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h
index 19e0d88b966..6a84ed166ae 100644
--- a/arch/x86/include/asm/smp.h
+++ b/arch/x86/include/asm/smp.h
@@ -180,7 +180,7 @@ extern int safe_smp_processor_id(void);
static inline int logical_smp_processor_id(void)
{
/* we don't want to mark this access volatile - bad code generation */
- return GET_APIC_LOGICAL_ID(*(u32 *)(APIC_BASE + APIC_LDR));
+ return GET_APIC_LOGICAL_ID(apic_read(APIC_LDR));
}
#endif
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 07cffc1214c..b0fd26442c4 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -242,17 +242,24 @@ static int modern_apic(void)
* bare function to substitute write operation
* and it's _that_ fast :)
*/
-void native_apic_write_dummy(u32 reg, u32 v)
+static void native_apic_write_dummy(u32 reg, u32 v)
{
WARN_ON_ONCE((cpu_has_apic || !disable_apic));
}
+static u32 native_apic_read_dummy(u32 reg)
+{
+ WARN_ON_ONCE((cpu_has_apic || !disable_apic));
+ return 0;
+}
+
/*
- * right after this call apic->write doesn't do anything
+ * right after this call apic->write/read doesn't do anything
* note that there is no restore operation it works one way
*/
void apic_disable(void)
{
+ apic->read = native_apic_read_dummy;
apic->write = native_apic_write_dummy;
}
@@ -1576,32 +1583,23 @@ void __init init_apic_mappings(void)
return;
}
- /*
- * If no local APIC can be found then set up a fake all
- * zeroes page to simulate the local APIC and another
- * one for the IO-APIC.
- */
+ /* If no local APIC can be found return early */
if (!smp_found_config && detect_init_APIC()) {
- apic_phys = (unsigned long) alloc_bootmem_pages(PAGE_SIZE);
- apic_phys = __pa(apic_phys);
- } else
+ /* lets NOP'ify apic operations */
+ pr_info("APIC: disable apic facility\n");
+ apic_disable();
+ } else {
apic_phys = mp_lapic_addr;
- /*
- * acpi lapic path already maps that address in
- * acpi_register_lapic_address()
- */
- if (!acpi_lapic)
- set_fixmap_nocache(FIX_APIC_BASE, apic_phys);
-
- apic_printk(APIC_VERBOSE, "mapped APIC to %08lx (%08lx)\n",
- APIC_BASE, apic_phys);
+ /*
+ * acpi lapic path already maps that address in
+ * acpi_register_lapic_address()
+ */
+ if (!acpi_lapic)
+ set_fixmap_nocache(FIX_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;
+ apic_printk(APIC_VERBOSE, "mapped APIC to %08lx (%08lx)\n",
+ APIC_BASE, apic_phys);
}
/*
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 1f3d3669dae..74d2b480a20 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -1878,6 +1878,11 @@ __apicdebuginit(void) print_PIC(void)
__apicdebuginit(int) print_all_ICs(void)
{
print_PIC();
+
+ /* don't print out if apic is not there */
+ if (!cpu_has_apic || disable_apic)
+ return 0;
+
print_all_local_APICs();
print_IO_APIC();