Commit 2f6df03f authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Dave Hansen
Browse files

x86/apic: Nuke empty init_apic_ldr() callbacks 



apic::init_apic_ldr() is only invoked when the APIC is initialized. So
there is really no point in having:

  - Default empty callbacks all over the place

  - Two implementations of the actual LDR init function where one is
    just unreadable gunk but does exactly the same as the other.

Make the apic::init_apic_ldr() invocation conditional, remove the empty
callbacks and consolidate the two implementation into one.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarDave Hansen <dave.hansen@linux.intel.com>
Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: default avatarMichael Kelley <mikelley@microsoft.com>
Tested-by: default avatarSohil Mehta <sohil.mehta@intel.com>
Tested-by: Juergen Gross <jgross@suse.com> # Xen PV (dom0 and unpriv. guest)
parent 4114e168

arch/x86/include/asm/apic.h

+0 −2
Original line number Diff line number Diff line
@@ -445,8 +445,6 @@ extern void generic_bigsmp_probe(void); 


#include <asm/smp.h>



#define APIC_DFR_VALUE	(APIC_DFR_FLAT)



extern struct apic apic_noop;



static inline unsigned int read_apic_id(void)

arch/x86/kernel/apic/apic.c

+5 −2
Original line number Diff line number Diff line
@@ -1578,8 +1578,11 @@ static void setup_local_APIC(void) 
	/*

	 * Intel recommends to set DFR, LDR and TPR before enabling

	 * an APIC.  See e.g. "AP-388 82489DX User's Manual" (Intel

	 * document number 292116).  So here it goes...

	 * document number 292116).

	 *

	 * Except for APICs which operate in physical destination mode.

	 */

	if (apic->init_apic_ldr)

		apic->init_apic_ldr();



	/*

arch/x86/kernel/apic/apic_common.c

+16 −0
Original line number Diff line number Diff line
@@ -6,6 +6,8 @@ 
#include <linux/irq.h>

#include <asm/apic.h>



#include "local.h"



u32 apic_default_calc_apicid(unsigned int cpu)

{

	return per_cpu(x86_cpu_to_apicid, cpu);
@@ -39,3 +41,17 @@ int default_apic_id_valid(u32 apicid) 
{

	return (apicid < 255);

}



/*

 * Set up the logical destination ID when the APIC operates in logical

 * destination mode.

 */

void default_init_apic_ldr(void)

{

	unsigned long val;



	apic_write(APIC_DFR, APIC_DFR_FLAT);

	val = apic_read(APIC_LDR) & ~APIC_LDR_MASK;

	val |= SET_APIC_LOGICAL_ID(1UL << smp_processor_id());

	apic_write(APIC_LDR, val);

}

arch/x86/kernel/apic/apic_flat_64.c

+1 −31
Original line number Diff line number Diff line
@@ -28,26 +28,6 @@ static int flat_acpi_madt_oem_check(char *oem_id, char *oem_table_id) 
	return 1;

}



/*

 * Set up the logical destination ID.

 *

 * Intel recommends to set DFR, LDR and TPR before enabling

 * an APIC.  See e.g. "AP-388 82489DX User's Manual" (Intel

 * document number 292116).  So here it goes...

 */

void flat_init_apic_ldr(void)

{

	unsigned long val;

	unsigned long num, id;



	num = smp_processor_id();

	id = 1UL << num;

	apic_write(APIC_DFR, APIC_DFR_FLAT);

	val = apic_read(APIC_LDR) & ~APIC_LDR_MASK;

	val |= SET_APIC_LOGICAL_ID(id);

	apic_write(APIC_LDR, val);

}



static void _flat_send_IPI_mask(unsigned long mask, int vector)

{

	unsigned long flags;
@@ -119,7 +99,7 @@ static struct apic apic_flat __ro_after_init = { 
	.disable_esr			= 0,



	.check_apicid_used		= NULL,

	.init_apic_ldr			= flat_init_apic_ldr,

	.init_apic_ldr			= default_init_apic_ldr,

	.ioapic_phys_id_map		= NULL,

	.setup_apic_routing		= NULL,

	.cpu_present_to_apicid		= default_cpu_present_to_apicid,
@@ -175,15 +155,6 @@ static int physflat_acpi_madt_oem_check(char *oem_id, char *oem_table_id) 
	return 0;

}



static void physflat_init_apic_ldr(void)

{

	/*

	 * LDR and DFR are not involved in physflat mode, rather:

	 * "In physical destination mode, the destination processor is

	 * specified by its local APIC ID [...]." (Intel SDM, 10.6.2.1)

	 */

}



static int physflat_probe(void)

{

	if (apic == &apic_physflat || num_possible_cpus() > 8 ||
@@ -207,7 +178,6 @@ static struct apic apic_physflat __ro_after_init = { 
	.disable_esr			= 0,



	.check_apicid_used		= NULL,

	.init_apic_ldr			= physflat_init_apic_ldr,

	.ioapic_phys_id_map		= NULL,

	.setup_apic_routing		= NULL,

	.cpu_present_to_apicid		= default_cpu_present_to_apicid,

arch/x86/kernel/apic/apic_noop.c

+0 −2
Original line number Diff line number Diff line
@@ -14,7 +14,6 @@ 


#include <asm/apic.h>



static void noop_init_apic_ldr(void) { }

static void noop_send_IPI(int cpu, int vector) { }

static void noop_send_IPI_mask(const struct cpumask *cpumask, int vector) { }

static void noop_send_IPI_mask_allbutself(const struct cpumask *cpumask, int vector) { }
@@ -94,7 +93,6 @@ struct apic apic_noop __ro_after_init = { 
	.disable_esr			= 0,



	.check_apicid_used		= default_check_apicid_used,

	.init_apic_ldr			= noop_init_apic_ldr,

	.ioapic_phys_id_map		= default_ioapic_phys_id_map,

	.setup_apic_routing		= NULL,

	.cpu_present_to_apicid		= default_cpu_present_to_apicid,