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x86/vsmp: Ignore IOAPIC IRQ affinity if possible

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vSMP can route interrupts more optimally based on internal
knowledge the OS does not have. In order to support this
optimization, all CPUs must be able to handle all possible
IOAPIC interrupts.

Fix this by setting the vector allocation domain for all CPUs
and by enabling this feature in vSMP.

Signed-off-by: Ravikiran Thirumalai <kiran.thirumalai@gmail.com>
Signed-off-by: Shai Fultheim <shai@scalemp.com>
[ Rebased, simplified, and reworded the commit message. ]
Signed-off-by: Ido Yariv <ido@wizery.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Ravikiran Thirumalai 2012-06-03 01:11:35 +03:00 committed by Ingo Molnar
parent 7db971b235
commit 110c1e1f1b
1 changed files with 23 additions and 4 deletions
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27
arch/x86/kernel/vsmp_64.c
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@ -16,6 +16,7 @@
#include <linux/pci_ids.h>
#include <linux/pci_regs.h>
#include <linux/smp.h>
#include <linux/irq.h>
#include <asm/apic.h>
#include <asm/pci-direct.h>
@ -95,6 +96,15 @@ static void __init set_vsmp_pv_ops(void)
ctl = readl(address + 4);
printk(KERN_INFO "vSMP CTL: capabilities:0x%08x control:0x%08x\n",
cap, ctl);
/* If possible, let the vSMP foundation route the interrupt optimally */
#ifdef CONFIG_SMP
if (cap & ctl & BIT(8)) {
ctl &= ~BIT(8);
no_irq_affinity = 1;
}
#endif
if (cap & ctl & (1 << 4)) {
/* Setup irq ops and turn on vSMP IRQ fastpath handling */
pv_irq_ops.irq_disable = PV_CALLEE_SAVE(vsmp_irq_disable);
@ -102,12 +112,11 @@ static void __init set_vsmp_pv_ops(void)
pv_irq_ops.save_fl = PV_CALLEE_SAVE(vsmp_save_fl);
pv_irq_ops.restore_fl = PV_CALLEE_SAVE(vsmp_restore_fl);
pv_init_ops.patch = vsmp_patch;
ctl &= ~(1 << 4);
writel(ctl, address + 4);
ctl = readl(address + 4);
printk(KERN_INFO "vSMP CTL: control set to:0x%08x\n", ctl);
}
writel(ctl, address + 4);
ctl = readl(address + 4);
pr_info("vSMP CTL: control set to:0x%08x\n", ctl);
early_iounmap(address, 8);
}
@ -192,10 +201,20 @@ static int apicid_phys_pkg_id(int initial_apic_id, int index_msb)
return hard_smp_processor_id() >> index_msb;
}
/*
* In vSMP, all cpus should be capable of handling interrupts, regardless of
* the APIC used.
*/
static void fill_vector_allocation_domain(int cpu, struct cpumask *retmask)
{
cpumask_setall(retmask);
}
static void vsmp_apic_post_init(void)
{
/* need to update phys_pkg_id */
apic->phys_pkg_id = apicid_phys_pkg_id;
apic->vector_allocation_domain = fill_vector_allocation_domain;
}
void __init vsmp_init(void)