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-rw-r--r--arch/x86/hyperv/irqdomain.c385
1 files changed, 385 insertions, 0 deletions
diff --git a/arch/x86/hyperv/irqdomain.c b/arch/x86/hyperv/irqdomain.c
new file mode 100644
index 000000000000..4421a8d92e23
--- /dev/null
+++ b/arch/x86/hyperv/irqdomain.c
@@ -0,0 +1,385 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Irqdomain for Linux to run as the root partition on Microsoft Hypervisor.
+ *
+ * Authors:
+ * Sunil Muthuswamy <sunilmut@microsoft.com>
+ * Wei Liu <wei.liu@kernel.org>
+ */
+
+#include <linux/pci.h>
+#include <linux/irq.h>
+#include <asm/mshyperv.h>
+
+static int hv_map_interrupt(union hv_device_id device_id, bool level,
+ int cpu, int vector, struct hv_interrupt_entry *entry)
+{
+ struct hv_input_map_device_interrupt *input;
+ struct hv_output_map_device_interrupt *output;
+ struct hv_device_interrupt_descriptor *intr_desc;
+ unsigned long flags;
+ u64 status;
+ int nr_bank, var_size;
+
+ local_irq_save(flags);
+
+ input = *this_cpu_ptr(hyperv_pcpu_input_arg);
+ output = *this_cpu_ptr(hyperv_pcpu_output_arg);
+
+ intr_desc = &input->interrupt_descriptor;
+ memset(input, 0, sizeof(*input));
+ input->partition_id = hv_current_partition_id;
+ input->device_id = device_id.as_uint64;
+ intr_desc->interrupt_type = HV_X64_INTERRUPT_TYPE_FIXED;
+ intr_desc->vector_count = 1;
+ intr_desc->target.vector = vector;
+
+ if (level)
+ intr_desc->trigger_mode = HV_INTERRUPT_TRIGGER_MODE_LEVEL;
+ else
+ intr_desc->trigger_mode = HV_INTERRUPT_TRIGGER_MODE_EDGE;
+
+ intr_desc->target.vp_set.valid_bank_mask = 0;
+ intr_desc->target.vp_set.format = HV_GENERIC_SET_SPARSE_4K;
+ nr_bank = cpumask_to_vpset(&(intr_desc->target.vp_set), cpumask_of(cpu));
+ if (nr_bank < 0) {
+ local_irq_restore(flags);
+ pr_err("%s: unable to generate VP set\n", __func__);
+ return EINVAL;
+ }
+ intr_desc->target.flags = HV_DEVICE_INTERRUPT_TARGET_PROCESSOR_SET;
+
+ /*
+ * 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 = nr_bank + 1;
+
+ status = hv_do_rep_hypercall(HVCALL_MAP_DEVICE_INTERRUPT, 0, var_size,
+ input, output);
+ *entry = output->interrupt_entry;
+
+ local_irq_restore(flags);
+
+ if ((status & HV_HYPERCALL_RESULT_MASK) != HV_STATUS_SUCCESS)
+ pr_err("%s: hypercall failed, status %lld\n", __func__, status);
+
+ return status & HV_HYPERCALL_RESULT_MASK;
+}
+
+static int hv_unmap_interrupt(u64 id, struct hv_interrupt_entry *old_entry)
+{
+ unsigned long flags;
+ struct hv_input_unmap_device_interrupt *input;
+ struct hv_interrupt_entry *intr_entry;
+ u64 status;
+
+ local_irq_save(flags);
+ input = *this_cpu_ptr(hyperv_pcpu_input_arg);
+
+ memset(input, 0, sizeof(*input));
+ intr_entry = &input->interrupt_entry;
+ input->partition_id = hv_current_partition_id;
+ input->device_id = id;
+ *intr_entry = *old_entry;
+
+ status = hv_do_hypercall(HVCALL_UNMAP_DEVICE_INTERRUPT, input, NULL);
+ local_irq_restore(flags);
+
+ return status & HV_HYPERCALL_RESULT_MASK;
+}
+
+#ifdef CONFIG_PCI_MSI
+struct rid_data {
+ struct pci_dev *bridge;
+ u32 rid;
+};
+
+static int get_rid_cb(struct pci_dev *pdev, u16 alias, void *data)
+{
+ struct rid_data *rd = data;
+ u8 bus = PCI_BUS_NUM(rd->rid);
+
+ if (pdev->bus->number != bus || PCI_BUS_NUM(alias) != bus) {
+ rd->bridge = pdev;
+ rd->rid = alias;
+ }
+
+ return 0;
+}
+
+static union hv_device_id hv_build_pci_dev_id(struct pci_dev *dev)
+{
+ union hv_device_id dev_id;
+ struct rid_data data = {
+ .bridge = NULL,
+ .rid = PCI_DEVID(dev->bus->number, dev->devfn)
+ };
+
+ pci_for_each_dma_alias(dev, get_rid_cb, &data);
+
+ dev_id.as_uint64 = 0;
+ dev_id.device_type = HV_DEVICE_TYPE_PCI;
+ dev_id.pci.segment = pci_domain_nr(dev->bus);
+
+ dev_id.pci.bdf.bus = PCI_BUS_NUM(data.rid);
+ dev_id.pci.bdf.device = PCI_SLOT(data.rid);
+ dev_id.pci.bdf.function = PCI_FUNC(data.rid);
+ dev_id.pci.source_shadow = HV_SOURCE_SHADOW_NONE;
+
+ if (data.bridge) {
+ int pos;
+
+ /*
+ * Microsoft Hypervisor requires a bus range when the bridge is
+ * running in PCI-X mode.
+ *
+ * To distinguish conventional vs PCI-X bridge, we can check
+ * the bridge's PCI-X Secondary Status Register, Secondary Bus
+ * Mode and Frequency bits. See PCI Express to PCI/PCI-X Bridge
+ * Specification Revision 1.0 5.2.2.1.3.
+ *
+ * Value zero means it is in conventional mode, otherwise it is
+ * in PCI-X mode.
+ */
+
+ pos = pci_find_capability(data.bridge, PCI_CAP_ID_PCIX);
+ if (pos) {
+ u16 status;
+
+ pci_read_config_word(data.bridge, pos +
+ PCI_X_BRIDGE_SSTATUS, &status);
+
+ if (status & PCI_X_SSTATUS_FREQ) {
+ /* Non-zero, PCI-X mode */
+ u8 sec_bus, sub_bus;
+
+ dev_id.pci.source_shadow = HV_SOURCE_SHADOW_BRIDGE_BUS_RANGE;
+
+ pci_read_config_byte(data.bridge, PCI_SECONDARY_BUS, &sec_bus);
+ dev_id.pci.shadow_bus_range.secondary_bus = sec_bus;
+ pci_read_config_byte(data.bridge, PCI_SUBORDINATE_BUS, &sub_bus);
+ dev_id.pci.shadow_bus_range.subordinate_bus = sub_bus;
+ }
+ }
+ }
+
+ return dev_id;
+}
+
+static int hv_map_msi_interrupt(struct pci_dev *dev, int cpu, int vector,
+ struct hv_interrupt_entry *entry)
+{
+ union hv_device_id device_id = hv_build_pci_dev_id(dev);
+
+ return hv_map_interrupt(device_id, false, cpu, vector, entry);
+}
+
+static inline void entry_to_msi_msg(struct hv_interrupt_entry *entry, struct msi_msg *msg)
+{
+ /* High address is always 0 */
+ msg->address_hi = 0;
+ msg->address_lo = entry->msi_entry.address.as_uint32;
+ msg->data = entry->msi_entry.data.as_uint32;
+}
+
+static int hv_unmap_msi_interrupt(struct pci_dev *dev, struct hv_interrupt_entry *old_entry);
+static void hv_irq_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
+{
+ struct msi_desc *msidesc;
+ struct pci_dev *dev;
+ struct hv_interrupt_entry out_entry, *stored_entry;
+ struct irq_cfg *cfg = irqd_cfg(data);
+ cpumask_t *affinity;
+ int cpu;
+ u64 status;
+
+ msidesc = irq_data_get_msi_desc(data);
+ dev = msi_desc_to_pci_dev(msidesc);
+
+ if (!cfg) {
+ pr_debug("%s: cfg is NULL", __func__);
+ return;
+ }
+
+ affinity = irq_data_get_effective_affinity_mask(data);
+ cpu = cpumask_first_and(affinity, cpu_online_mask);
+
+ if (data->chip_data) {
+ /*
+ * This interrupt is already mapped. Let's unmap first.
+ *
+ * We don't use retarget interrupt hypercalls here because
+ * Microsoft Hypervisor doens't allow root to change the vector
+ * or specify VPs outside of the set that is initially used
+ * during mapping.
+ */
+ stored_entry = data->chip_data;
+ data->chip_data = NULL;
+
+ status = hv_unmap_msi_interrupt(dev, stored_entry);
+
+ kfree(stored_entry);
+
+ if (status != HV_STATUS_SUCCESS) {
+ pr_debug("%s: failed to unmap, status %lld", __func__, status);
+ return;
+ }
+ }
+
+ stored_entry = kzalloc(sizeof(*stored_entry), GFP_ATOMIC);
+ if (!stored_entry) {
+ pr_debug("%s: failed to allocate chip data\n", __func__);
+ return;
+ }
+
+ status = hv_map_msi_interrupt(dev, cpu, cfg->vector, &out_entry);
+ if (status != HV_STATUS_SUCCESS) {
+ kfree(stored_entry);
+ return;
+ }
+
+ *stored_entry = out_entry;
+ data->chip_data = stored_entry;
+ entry_to_msi_msg(&out_entry, msg);
+
+ return;
+}
+
+static int hv_unmap_msi_interrupt(struct pci_dev *dev, struct hv_interrupt_entry *old_entry)
+{
+ return hv_unmap_interrupt(hv_build_pci_dev_id(dev).as_uint64, old_entry);
+}
+
+static void hv_teardown_msi_irq_common(struct pci_dev *dev, struct msi_desc *msidesc, int irq)
+{
+ u64 status;
+ struct hv_interrupt_entry old_entry;
+ struct irq_desc *desc;
+ struct irq_data *data;
+ struct msi_msg msg;
+
+ desc = irq_to_desc(irq);
+ if (!desc) {
+ pr_debug("%s: no irq desc\n", __func__);
+ return;
+ }
+
+ data = &desc->irq_data;
+ if (!data) {
+ pr_debug("%s: no irq data\n", __func__);
+ return;
+ }
+
+ if (!data->chip_data) {
+ pr_debug("%s: no chip data\n!", __func__);
+ return;
+ }
+
+ old_entry = *(struct hv_interrupt_entry *)data->chip_data;
+ entry_to_msi_msg(&old_entry, &msg);
+
+ kfree(data->chip_data);
+ data->chip_data = NULL;
+
+ status = hv_unmap_msi_interrupt(dev, &old_entry);
+
+ if (status != HV_STATUS_SUCCESS) {
+ pr_err("%s: hypercall failed, status %lld\n", __func__, status);
+ return;
+ }
+}
+
+static void hv_msi_domain_free_irqs(struct irq_domain *domain, struct device *dev)
+{
+ int i;
+ struct msi_desc *entry;
+ struct pci_dev *pdev;
+
+ if (WARN_ON_ONCE(!dev_is_pci(dev)))
+ return;
+
+ pdev = to_pci_dev(dev);
+
+ for_each_pci_msi_entry(entry, pdev) {
+ if (entry->irq) {
+ for (i = 0; i < entry->nvec_used; i++) {
+ hv_teardown_msi_irq_common(pdev, entry, entry->irq + i);
+ irq_domain_free_irqs(entry->irq + i, 1);
+ }
+ }
+ }
+}
+
+/*
+ * IRQ Chip for MSI PCI/PCI-X/PCI-Express Devices,
+ * which implement the MSI or MSI-X Capability Structure.
+ */
+static struct irq_chip hv_pci_msi_controller = {
+ .name = "HV-PCI-MSI",
+ .irq_unmask = pci_msi_unmask_irq,
+ .irq_mask = pci_msi_mask_irq,
+ .irq_ack = irq_chip_ack_parent,
+ .irq_retrigger = irq_chip_retrigger_hierarchy,
+ .irq_compose_msi_msg = hv_irq_compose_msi_msg,
+ .irq_set_affinity = msi_domain_set_affinity,
+ .flags = IRQCHIP_SKIP_SET_WAKE,
+};
+
+static struct msi_domain_ops pci_msi_domain_ops = {
+ .domain_free_irqs = hv_msi_domain_free_irqs,
+ .msi_prepare = pci_msi_prepare,
+};
+
+static struct msi_domain_info hv_pci_msi_domain_info = {
+ .flags = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
+ MSI_FLAG_PCI_MSIX,
+ .ops = &pci_msi_domain_ops,
+ .chip = &hv_pci_msi_controller,
+ .handler = handle_edge_irq,
+ .handler_name = "edge",
+};
+
+struct irq_domain * __init hv_create_pci_msi_domain(void)
+{
+ struct irq_domain *d = NULL;
+ struct fwnode_handle *fn;
+
+ fn = irq_domain_alloc_named_fwnode("HV-PCI-MSI");
+ if (fn)
+ d = pci_msi_create_irq_domain(fn, &hv_pci_msi_domain_info, x86_vector_domain);
+
+ /* No point in going further if we can't get an irq domain */
+ BUG_ON(!d);
+
+ return d;
+}
+
+#endif /* CONFIG_PCI_MSI */
+
+int hv_unmap_ioapic_interrupt(int ioapic_id, struct hv_interrupt_entry *entry)
+{
+ union hv_device_id device_id;
+
+ device_id.as_uint64 = 0;
+ device_id.device_type = HV_DEVICE_TYPE_IOAPIC;
+ device_id.ioapic.ioapic_id = (u8)ioapic_id;
+
+ return hv_unmap_interrupt(device_id.as_uint64, entry);
+}
+EXPORT_SYMBOL_GPL(hv_unmap_ioapic_interrupt);
+
+int hv_map_ioapic_interrupt(int ioapic_id, bool level, int cpu, int vector,
+ struct hv_interrupt_entry *entry)
+{
+ union hv_device_id device_id;
+
+ device_id.as_uint64 = 0;
+ device_id.device_type = HV_DEVICE_TYPE_IOAPIC;
+ device_id.ioapic.ioapic_id = (u8)ioapic_id;
+
+ return hv_map_interrupt(device_id, level, cpu, vector, entry);
+}
+EXPORT_SYMBOL_GPL(hv_map_ioapic_interrupt);