提交 4797f6b0 编写于 作者: Y Yinghai Lu 提交者: Ingo Molnar

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: NEd Swierk <eswierk@aristanetworks.com>
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Acked-by: NCyrill Gorcunov <gorcunov@openvz.org>
LKML-Reference: <49FC85A9.2070702@kernel.org>
[ v4: sanity-check in the ACPI case too ]
Signed-off-by: NIngo Molnar <mingo@elte.hu>
上级 6cda3eb6
......@@ -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
......
......@@ -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);
}
/*
......
......@@ -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();
......
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