Commit cff9ab2b authored by Denys Vlasenko's avatar Denys Vlasenko Committed by Thomas Gleixner
Browse files

x86/apic: Get rid of apic_version[] array 



The array has a size of MAX_LOCAL_APIC, which can be as large as 32k, so it
can consume up to 128k.

The array has been there forever and was never used for anything useful
other than a version mismatch check which was introduced in 2009.

There is no reason to store the version in an array. The kernel is not
prepared to handle different APIC versions anyway, so the real important
part is to detect a version mismatch and warn about it, which can be done
with a single variable as well.

[ tglx: Massaged changelog ]

Signed-off-by: default avatarDenys Vlasenko <dvlasenk@redhat.com>
CC: Andy Lutomirski <luto@amacapital.net>
CC: Borislav Petkov <bp@alien8.de>
CC: Brian Gerst <brgerst@gmail.com>
CC: Mike Travis <travis@sgi.com>
Link: http://lkml.kernel.org/r/20160913181232.30815-1-dvlasenk@redhat.com


Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent b0f48706

arch/x86/include/asm/mpspec.h

+1 −1
Original line number Diff line number Diff line
@@ -6,7 +6,6 @@ 
#include <asm/x86_init.h>

#include <asm/apicdef.h>



extern int apic_version[];

extern int pic_mode;



#ifdef CONFIG_X86_32
@@ -40,6 +39,7 @@ extern int mp_bus_id_to_type[MAX_MP_BUSSES]; 
extern DECLARE_BITMAP(mp_bus_not_pci, MAX_MP_BUSSES);



extern unsigned int boot_cpu_physical_apicid;

extern u8 boot_cpu_apic_version;

extern unsigned long mp_lapic_addr;



#ifdef CONFIG_X86_LOCAL_APIC

arch/x86/kernel/acpi/boot.c

+1 −1
Original line number Diff line number Diff line
@@ -182,7 +182,7 @@ static int acpi_register_lapic(int id, u32 acpiid, u8 enabled) 
	}



	if (boot_cpu_physical_apicid != -1U)

		ver = apic_version[boot_cpu_physical_apicid];

		ver = boot_cpu_apic_version;



	cpu = generic_processor_info(id, ver);

	if (cpu >= 0)

arch/x86/kernel/apic/apic.c

+7 −10
Original line number Diff line number Diff line
@@ -64,6 +64,8 @@ unsigned disabled_cpus; 
unsigned int boot_cpu_physical_apicid = -1U;

EXPORT_SYMBOL_GPL(boot_cpu_physical_apicid);



u8 boot_cpu_apic_version;



/*

 * The highest APIC ID seen during enumeration.

 */
@@ -1812,8 +1814,7 @@ void __init init_apic_mappings(void) 
		 * since smp_sanity_check is prepared for such a case

		 * and disable smp mode

		 */

		apic_version[new_apicid] =

			 GET_APIC_VERSION(apic_read(APIC_LVR));

		boot_cpu_apic_version = GET_APIC_VERSION(apic_read(APIC_LVR));

	}

}
@@ -1828,13 +1829,10 @@ void __init register_lapic_address(unsigned long address) 
	}

	if (boot_cpu_physical_apicid == -1U) {

		boot_cpu_physical_apicid  = read_apic_id();

		apic_version[boot_cpu_physical_apicid] =

			 GET_APIC_VERSION(apic_read(APIC_LVR));

		boot_cpu_apic_version = GET_APIC_VERSION(apic_read(APIC_LVR));

	}

}



int apic_version[MAX_LOCAL_APIC];



/*

 * Local APIC interrupts

 */
@@ -2124,11 +2122,10 @@ int generic_processor_info(int apicid, int version) 
			   cpu, apicid);

		version = 0x10;

	}

	apic_version[apicid] = version;



	if (version != apic_version[boot_cpu_physical_apicid]) {

	if (version != boot_cpu_apic_version) {

		pr_warning("BIOS bug: APIC version mismatch, boot CPU: %x, CPU %d: version %x\n",

			apic_version[boot_cpu_physical_apicid], cpu, version);

			boot_cpu_apic_version, cpu, version);

	}



	physid_set(apicid, phys_cpu_present_map);
@@ -2271,7 +2268,7 @@ int __init APIC_init_uniprocessor(void) 
	 * Complain if the BIOS pretends there is one.

	 */

	if (!boot_cpu_has(X86_FEATURE_APIC) &&

	    APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) {

	    APIC_INTEGRATED(boot_cpu_apic_version)) {

		pr_err("BIOS bug, local APIC 0x%x not detected!...\n",

			boot_cpu_physical_apicid);

		return -1;

arch/x86/kernel/apic/io_apic.c

+2 −2
Original line number Diff line number Diff line
@@ -1593,7 +1593,7 @@ void __init setup_ioapic_ids_from_mpc(void) 
	 * no meaning without the serial APIC bus.

	 */

	if (!(boot_cpu_data.x86_vendor == X86_VENDOR_INTEL)

		|| APIC_XAPIC(apic_version[boot_cpu_physical_apicid]))

		|| APIC_XAPIC(boot_cpu_apic_version))

		return;

	setup_ioapic_ids_from_mpc_nocheck();

}
@@ -2423,7 +2423,7 @@ static int io_apic_get_unique_id(int ioapic, int apic_id) 
static u8 io_apic_unique_id(int idx, u8 id)

{

	if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&

	    !APIC_XAPIC(apic_version[boot_cpu_physical_apicid]))

	    !APIC_XAPIC(boot_cpu_apic_version))

		return io_apic_get_unique_id(idx, id);

	else

		return id;

arch/x86/kernel/apic/probe_32.c

+1 −1
Original line number Diff line number Diff line
@@ -152,7 +152,7 @@ early_param("apic", parse_apic); 


void __init default_setup_apic_routing(void)

{

	int version = apic_version[boot_cpu_physical_apicid];

	int version = boot_cpu_apic_version;



	if (num_possible_cpus() > 8) {

		switch (boot_cpu_data.x86_vendor) {

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