PCI: hv: Switch to msi_create_parent_irq_domain()

Move away from the legacy MSI domain setup, switch to use
msi_create_parent_irq_domain().

While doing the conversion, I noticed that hv_compose_msi_msg() is doing
more than it is supposed to (composing message). This function also
allocates and populates struct tran_int_desc, which should be done in
hv_pcie_domain_alloc() instead. It works, but it is not the correct design.
However, I have no hardware to test such change, therefore I leave a TODO
note.

Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Nam Cao <namcao@linutronix.de>
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index 9c0e4aaf4e8cb7fecd9f80ac6289b8d854ce03aa..9a249c65aedcd6b55437df3e8fb7b72c3985a283 100644 (file)
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -223,6 +223,7 @@ config PCI_HYPERV
        tristate "Hyper-V PCI Frontend"
        depends on ((X86 && X86_64) || ARM64) && HYPERV && PCI_MSI && SYSFS
        select PCI_HYPERV_INTERFACE
+       select IRQ_MSI_LIB
        help
          The PCI device frontend driver allows the kernel to import arbitrary
          PCI devices from a PCI backend to support PCI driver domains.

diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index 86ca041bf74a78810fc4910fd3988202ce326abf..ebe39218479aa3c87aa0b469e2a2c596836ccbb1 100644 (file)
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -44,6 +44,7 @@
 #include <linux/delay.h>
 #include <linux/semaphore.h>
 #include <linux/irq.h>
+#include <linux/irqchip/irq-msi-lib.h>
 #include <linux/msi.h>
 #include <linux/hyperv.h>
 #include <linux/refcount.h>
@@ -508,7 +509,6 @@ struct hv_pcibus_device {
        struct list_head children;
        struct list_head dr_list;
 
-       struct msi_domain_info msi_info;
        struct irq_domain *irq_domain;
 
        struct workqueue_struct *wq;
@@ -576,9 +576,8 @@ struct hv_pci_compl {
 static void hv_pci_onchannelcallback(void *context);
 
 #ifdef CONFIG_X86
-#define DELIVERY_MODE  APIC_DELIVERY_MODE_FIXED
-#define FLOW_HANDLER   handle_edge_irq
-#define FLOW_NAME      "edge"
+#define DELIVERY_MODE          APIC_DELIVERY_MODE_FIXED
+#define HV_MSI_CHIP_FLAGS      MSI_CHIP_FLAG_SET_ACK
 
 static int hv_pci_irqchip_init(void)
 {
@@ -723,8 +722,7 @@ out:
 #define HV_PCI_MSI_SPI_START   64
 #define HV_PCI_MSI_SPI_NR      (1020 - HV_PCI_MSI_SPI_START)
 #define DELIVERY_MODE          0
-#define FLOW_HANDLER           NULL
-#define FLOW_NAME              NULL
+#define HV_MSI_CHIP_FLAGS      MSI_CHIP_FLAG_SET_EOI
 #define hv_msi_prepare         NULL
 
 struct hv_pci_chip_data {
@@ -1687,7 +1685,7 @@ static void hv_msi_free(struct irq_domain *domain, struct msi_domain_info *info,
        struct msi_desc *msi = irq_data_get_msi_desc(irq_data);
 
        pdev = msi_desc_to_pci_dev(msi);
-       hbus = info->data;
+       hbus = domain->host_data;
        int_desc = irq_data_get_irq_chip_data(irq_data);
        if (!int_desc)
                return;
@@ -1705,7 +1703,6 @@ static void hv_msi_free(struct irq_domain *domain, struct msi_domain_info *info,
 
 static void hv_irq_mask(struct irq_data *data)
 {
-       pci_msi_mask_irq(data);
        if (data->parent_data->chip->irq_mask)
                irq_chip_mask_parent(data);
 }
@@ -1716,7 +1713,6 @@ static void hv_irq_unmask(struct irq_data *data)
 
        if (data->parent_data->chip->irq_unmask)
                irq_chip_unmask_parent(data);
-       pci_msi_unmask_irq(data);
 }
 
 struct compose_comp_ctxt {
@@ -2101,25 +2097,87 @@ return_null_message:
        msg->data = 0;
 }
 
+static bool hv_pcie_init_dev_msi_info(struct device *dev, struct irq_domain *domain,
+                                     struct irq_domain *real_parent, struct msi_domain_info *info)
+{
+       struct irq_chip *chip = info->chip;
+
+       if (!msi_lib_init_dev_msi_info(dev, domain, real_parent, info))
+               return false;
+
+       info->ops->msi_prepare = hv_msi_prepare;
+
+       chip->irq_set_affinity = irq_chip_set_affinity_parent;
+
+       if (IS_ENABLED(CONFIG_X86))
+               chip->flags |= IRQCHIP_MOVE_DEFERRED;
+
+       return true;
+}
+
+#define HV_PCIE_MSI_FLAGS_REQUIRED (MSI_FLAG_USE_DEF_DOM_OPS           | \
+                                   MSI_FLAG_USE_DEF_CHIP_OPS           | \
+                                   MSI_FLAG_PCI_MSI_MASK_PARENT)
+#define HV_PCIE_MSI_FLAGS_SUPPORTED (MSI_FLAG_MULTI_PCI_MSI            | \
+                                    MSI_FLAG_PCI_MSIX                  | \
+                                    MSI_FLAG_PCI_MSIX_ALLOC_DYN        | \
+                                    MSI_GENERIC_FLAGS_MASK)
+
+static const struct msi_parent_ops hv_pcie_msi_parent_ops = {
+       .required_flags         = HV_PCIE_MSI_FLAGS_REQUIRED,
+       .supported_flags        = HV_PCIE_MSI_FLAGS_SUPPORTED,
+       .bus_select_token       = DOMAIN_BUS_PCI_MSI,
+       .chip_flags             = HV_MSI_CHIP_FLAGS,
+       .prefix                 = "HV-",
+       .init_dev_msi_info      = hv_pcie_init_dev_msi_info,
+};
+
 /* HW Interrupt Chip Descriptor */
 static struct irq_chip hv_msi_irq_chip = {
        .name                   = "Hyper-V PCIe MSI",
        .irq_compose_msi_msg    = hv_compose_msi_msg,
        .irq_set_affinity       = irq_chip_set_affinity_parent,
-#ifdef CONFIG_X86
        .irq_ack                = irq_chip_ack_parent,
-       .flags                  = IRQCHIP_MOVE_DEFERRED,
-#elif defined(CONFIG_ARM64)
        .irq_eoi                = irq_chip_eoi_parent,
-#endif
        .irq_mask               = hv_irq_mask,
        .irq_unmask             = hv_irq_unmask,
 };
 
-static struct msi_domain_ops hv_msi_ops = {
-       .msi_prepare    = hv_msi_prepare,
-       .msi_free       = hv_msi_free,
-       .prepare_desc   = pci_msix_prepare_desc,
+static int hv_pcie_domain_alloc(struct irq_domain *d, unsigned int virq, unsigned int nr_irqs,
+                              void *arg)
+{
+       /*
+        * TODO: Allocating and populating struct tran_int_desc in hv_compose_msi_msg()
+        * should be moved here.
+        */
+       int ret;
+
+       ret = irq_domain_alloc_irqs_parent(d, virq, nr_irqs, arg);
+       if (ret < 0)
+               return ret;
+
+       for (int i = 0; i < nr_irqs; i++) {
+               irq_domain_set_hwirq_and_chip(d, virq + i, 0, &hv_msi_irq_chip, NULL);
+               if (IS_ENABLED(CONFIG_X86))
+                       __irq_set_handler(virq + i, handle_edge_irq, 0, "edge");
+       }
+
+       return 0;
+}
+
+static void hv_pcie_domain_free(struct irq_domain *d, unsigned int virq, unsigned int nr_irqs)
+{
+       struct msi_domain_info *info = d->host_data;
+
+       for (int i = 0; i < nr_irqs; i++)
+               hv_msi_free(d, info, virq + i);
+
+       irq_domain_free_irqs_top(d, virq, nr_irqs);
+}
+
+static const struct irq_domain_ops hv_pcie_domain_ops = {
+       .alloc  = hv_pcie_domain_alloc,
+       .free   = hv_pcie_domain_free,
 };
 
 /**
@@ -2137,17 +2195,14 @@ static struct msi_domain_ops hv_msi_ops = {
  */
 static int hv_pcie_init_irq_domain(struct hv_pcibus_device *hbus)
 {
-       hbus->msi_info.chip = &hv_msi_irq_chip;
-       hbus->msi_info.ops = &hv_msi_ops;
-       hbus->msi_info.flags = (MSI_FLAG_USE_DEF_DOM_OPS |
-               MSI_FLAG_USE_DEF_CHIP_OPS | MSI_FLAG_MULTI_PCI_MSI |
-               MSI_FLAG_PCI_MSIX | MSI_FLAG_PCI_MSIX_ALLOC_DYN);
-       hbus->msi_info.handler = FLOW_HANDLER;
-       hbus->msi_info.handler_name = FLOW_NAME;
-       hbus->msi_info.data = hbus;
-       hbus->irq_domain = pci_msi_create_irq_domain(hbus->fwnode,
-                                                    &hbus->msi_info,
-                                                    hv_pci_get_root_domain());
+       struct irq_domain_info info = {
+               .fwnode         = hbus->fwnode,
+               .ops            = &hv_pcie_domain_ops,
+               .host_data      = hbus,
+               .parent         = hv_pci_get_root_domain(),
+       };
+
+       hbus->irq_domain = msi_create_parent_irq_domain(&info, &hv_pcie_msi_parent_ops);
        if (!hbus->irq_domain) {
                dev_err(&hbus->hdev->device,
                        "Failed to build an MSI IRQ domain\n");