Commit 8a43a744 authored by Bjorn Helgaas's avatar Bjorn Helgaas
Browse files

Merge branch 'remotes/lorenzo/pci/hv' 

- Avoid retarget interrupt hypercall in irq_unmask() on ARM64 (Boqun Feng)

* remotes/lorenzo/pci/hv:
  PCI: hv: Avoid the retarget interrupt hypercall in irq_unmask() on ARM64
parents d93fefad d06957d7

drivers/pci/controller/pci-hyperv.c

+122 −111
Original line number Diff line number Diff line
@@ -616,6 +616,121 @@ static int hv_msi_prepare(struct irq_domain *domain, struct device *dev, 
{

	return pci_msi_prepare(domain, dev, nvec, info);

}



/**

 * hv_arch_irq_unmask() - "Unmask" the IRQ by setting its current

 * affinity.

 * @data:	Describes the IRQ

 *

 * Build new a destination for the MSI and make a hypercall to

 * update the Interrupt Redirection Table. "Device Logical ID"

 * is built out of this PCI bus's instance GUID and the function

 * number of the device.

 */

static void hv_arch_irq_unmask(struct irq_data *data)

{

	struct msi_desc *msi_desc = irq_data_get_msi_desc(data);

	struct hv_retarget_device_interrupt *params;

	struct hv_pcibus_device *hbus;

	struct cpumask *dest;

	cpumask_var_t tmp;

	struct pci_bus *pbus;

	struct pci_dev *pdev;

	unsigned long flags;

	u32 var_size = 0;

	int cpu, nr_bank;

	u64 res;



	dest = irq_data_get_effective_affinity_mask(data);

	pdev = msi_desc_to_pci_dev(msi_desc);

	pbus = pdev->bus;

	hbus = container_of(pbus->sysdata, struct hv_pcibus_device, sysdata);



	spin_lock_irqsave(&hbus->retarget_msi_interrupt_lock, flags);



	params = &hbus->retarget_msi_interrupt_params;

	memset(params, 0, sizeof(*params));

	params->partition_id = HV_PARTITION_ID_SELF;

	params->int_entry.source = HV_INTERRUPT_SOURCE_MSI;

	hv_set_msi_entry_from_desc(&params->int_entry.msi_entry, msi_desc);

	params->device_id = (hbus->hdev->dev_instance.b[5] << 24) |

			   (hbus->hdev->dev_instance.b[4] << 16) |

			   (hbus->hdev->dev_instance.b[7] << 8) |

			   (hbus->hdev->dev_instance.b[6] & 0xf8) |

			   PCI_FUNC(pdev->devfn);

	params->int_target.vector = hv_msi_get_int_vector(data);



	/*

	 * Honoring apic->delivery_mode set to APIC_DELIVERY_MODE_FIXED by

	 * setting the HV_DEVICE_INTERRUPT_TARGET_MULTICAST flag results in a

	 * spurious interrupt storm. Not doing so does not seem to have a

	 * negative effect (yet?).

	 */



	if (hbus->protocol_version >= PCI_PROTOCOL_VERSION_1_2) {

		/*

		 * PCI_PROTOCOL_VERSION_1_2 supports the VP_SET version of the

		 * HVCALL_RETARGET_INTERRUPT hypercall, which also coincides

		 * with >64 VP support.

		 * ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED

		 * is not sufficient for this hypercall.

		 */

		params->int_target.flags |=

			HV_DEVICE_INTERRUPT_TARGET_PROCESSOR_SET;



		if (!alloc_cpumask_var(&tmp, GFP_ATOMIC)) {

			res = 1;

			goto exit_unlock;

		}



		cpumask_and(tmp, dest, cpu_online_mask);

		nr_bank = cpumask_to_vpset(&params->int_target.vp_set, tmp);

		free_cpumask_var(tmp);



		if (nr_bank <= 0) {

			res = 1;

			goto exit_unlock;

		}



		/*

		 * var-sized hypercall, var-size starts after vp_mask (thus

		 * vp_set.format does not count, but vp_set.valid_bank_mask

		 * does).

		 */

		var_size = 1 + nr_bank;

	} else {

		for_each_cpu_and(cpu, dest, cpu_online_mask) {

			params->int_target.vp_mask |=

				(1ULL << hv_cpu_number_to_vp_number(cpu));

		}

	}



	res = hv_do_hypercall(HVCALL_RETARGET_INTERRUPT | (var_size << 17),

			      params, NULL);



exit_unlock:

	spin_unlock_irqrestore(&hbus->retarget_msi_interrupt_lock, flags);



	/*

	 * During hibernation, when a CPU is offlined, the kernel tries

	 * to move the interrupt to the remaining CPUs that haven't

	 * been offlined yet. In this case, the below hv_do_hypercall()

	 * always fails since the vmbus channel has been closed:

	 * refer to cpu_disable_common() -> fixup_irqs() ->

	 * irq_migrate_all_off_this_cpu() -> migrate_one_irq().

	 *

	 * Suppress the error message for hibernation because the failure

	 * during hibernation does not matter (at this time all the devices

	 * have been frozen). Note: the correct affinity info is still updated

	 * into the irqdata data structure in migrate_one_irq() ->

	 * irq_do_set_affinity() -> hv_set_affinity(), so later when the VM

	 * resumes, hv_pci_restore_msi_state() is able to correctly restore

	 * the interrupt with the correct affinity.

	 */

	if (!hv_result_success(res) && hbus->state != hv_pcibus_removing)

		dev_err(&hbus->hdev->device,

			"%s() failed: %#llx", __func__, res);

}

#elif defined(CONFIG_ARM64)

/*

 * SPI vectors to use for vPCI; arch SPIs range is [32, 1019], but leaving a bit
@@ -839,6 +954,12 @@ static struct irq_domain *hv_pci_get_root_domain(void) 
{

	return hv_msi_gic_irq_domain;

}



/*

 * SPIs are used for interrupts of PCI devices and SPIs is managed via GICD

 * registers which Hyper-V already supports, so no hypercall needed.

 */

static void hv_arch_irq_unmask(struct irq_data *data) { }

#endif /* CONFIG_ARM64 */



/**
@@ -1456,119 +1577,9 @@ static void hv_irq_mask(struct irq_data *data) 
		irq_chip_mask_parent(data);

}



/**

 * hv_irq_unmask() - "Unmask" the IRQ by setting its current

 * affinity.

 * @data:	Describes the IRQ

 *

 * Build new a destination for the MSI and make a hypercall to

 * update the Interrupt Redirection Table. "Device Logical ID"

 * is built out of this PCI bus's instance GUID and the function

 * number of the device.

 */

static void hv_irq_unmask(struct irq_data *data)

{

	struct msi_desc *msi_desc = irq_data_get_msi_desc(data);

	struct hv_retarget_device_interrupt *params;

	struct hv_pcibus_device *hbus;

	struct cpumask *dest;

	cpumask_var_t tmp;

	struct pci_bus *pbus;

	struct pci_dev *pdev;

	unsigned long flags;

	u32 var_size = 0;

	int cpu, nr_bank;

	u64 res;



	dest = irq_data_get_effective_affinity_mask(data);

	pdev = msi_desc_to_pci_dev(msi_desc);

	pbus = pdev->bus;

	hbus = container_of(pbus->sysdata, struct hv_pcibus_device, sysdata);



	spin_lock_irqsave(&hbus->retarget_msi_interrupt_lock, flags);



	params = &hbus->retarget_msi_interrupt_params;

	memset(params, 0, sizeof(*params));

	params->partition_id = HV_PARTITION_ID_SELF;

	params->int_entry.source = HV_INTERRUPT_SOURCE_MSI;

	hv_set_msi_entry_from_desc(&params->int_entry.msi_entry, msi_desc);

	params->device_id = (hbus->hdev->dev_instance.b[5] << 24) |

			   (hbus->hdev->dev_instance.b[4] << 16) |

			   (hbus->hdev->dev_instance.b[7] << 8) |

			   (hbus->hdev->dev_instance.b[6] & 0xf8) |

			   PCI_FUNC(pdev->devfn);

	params->int_target.vector = hv_msi_get_int_vector(data);



	/*

	 * Honoring apic->delivery_mode set to APIC_DELIVERY_MODE_FIXED by

	 * setting the HV_DEVICE_INTERRUPT_TARGET_MULTICAST flag results in a

	 * spurious interrupt storm. Not doing so does not seem to have a

	 * negative effect (yet?).

	 */



	if (hbus->protocol_version >= PCI_PROTOCOL_VERSION_1_2) {

		/*

		 * PCI_PROTOCOL_VERSION_1_2 supports the VP_SET version of the

		 * HVCALL_RETARGET_INTERRUPT hypercall, which also coincides

		 * with >64 VP support.

		 * ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED

		 * is not sufficient for this hypercall.

		 */

		params->int_target.flags |=

			HV_DEVICE_INTERRUPT_TARGET_PROCESSOR_SET;



		if (!alloc_cpumask_var(&tmp, GFP_ATOMIC)) {

			res = 1;

			goto exit_unlock;

		}



		cpumask_and(tmp, dest, cpu_online_mask);

		nr_bank = cpumask_to_vpset(&params->int_target.vp_set, tmp);

		free_cpumask_var(tmp);



		if (nr_bank <= 0) {

			res = 1;

			goto exit_unlock;

		}



		/*

		 * var-sized hypercall, var-size starts after vp_mask (thus

		 * vp_set.format does not count, but vp_set.valid_bank_mask

		 * does).

		 */

		var_size = 1 + nr_bank;

	} else {

		for_each_cpu_and(cpu, dest, cpu_online_mask) {

			params->int_target.vp_mask |=

				(1ULL << hv_cpu_number_to_vp_number(cpu));

		}

	}



	res = hv_do_hypercall(HVCALL_RETARGET_INTERRUPT | (var_size << 17),

			      params, NULL);



exit_unlock:

	spin_unlock_irqrestore(&hbus->retarget_msi_interrupt_lock, flags);



	/*

	 * During hibernation, when a CPU is offlined, the kernel tries

	 * to move the interrupt to the remaining CPUs that haven't

	 * been offlined yet. In this case, the below hv_do_hypercall()

	 * always fails since the vmbus channel has been closed:

	 * refer to cpu_disable_common() -> fixup_irqs() ->

	 * irq_migrate_all_off_this_cpu() -> migrate_one_irq().

	 *

	 * Suppress the error message for hibernation because the failure

	 * during hibernation does not matter (at this time all the devices

	 * have been frozen). Note: the correct affinity info is still updated

	 * into the irqdata data structure in migrate_one_irq() ->

	 * irq_do_set_affinity() -> hv_set_affinity(), so later when the VM

	 * resumes, hv_pci_restore_msi_state() is able to correctly restore

	 * the interrupt with the correct affinity.

	 */

	if (!hv_result_success(res) && hbus->state != hv_pcibus_removing)

		dev_err(&hbus->hdev->device,

			"%s() failed: %#llx", __func__, res);

	hv_arch_irq_unmask(data);



	if (data->parent_data->chip->irq_unmask)

		irq_chip_unmask_parent(data);