From: Sunil Muthuswamy <sunilmut@xxxxxxxxxxxxxxxxxxx> Sent: Wednesday, November 10, 2021 11:45 AM
>
> Add support for Hyper-V vPCI for arm64 by implementing the arch specific
> interfaces. Introduce an IRQ domain and chip specific to Hyper-v vPCI that
> is based on SPIs. The IRQ domain parents itself to the arch GIC IRQ domain
> for basic vector management.
>
> Signed-off-by: Sunil Muthuswamy <sunilmut@xxxxxxxxxxxxx>
> ---
> In v2, v3, v4 & v5:
> Changes are described in the cover letter.
>
> arch/arm64/include/asm/hyperv-tlfs.h | 9 ++
> drivers/pci/Kconfig | 2 +-
> drivers/pci/controller/Kconfig | 2 +-
> drivers/pci/controller/pci-hyperv.c | 204 ++++++++++++++++++++++++++-
> 4 files changed, 214 insertions(+), 3 deletions(-)
>
[snip]
> diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
> index 03e07a4f0e3f..b13e3ae5a34f 100644
> --- a/drivers/pci/controller/pci-hyperv.c
> +++ b/drivers/pci/controller/pci-hyperv.c
> @@ -47,6 +47,8 @@
> #include <linux/msi.h>
> #include <linux/hyperv.h>
> #include <linux/refcount.h>
> +#include <linux/irqdomain.h>
> +#include <linux/acpi.h>
> #include <asm/mshyperv.h>
>
> /*
> @@ -614,7 +616,202 @@ static int hv_msi_prepare(struct irq_domain *domain, struct device *dev,
> {
> return pci_msi_prepare(domain, dev, nvec, info);
> }
> -#endif // CONFIG_X86
> +#elif defined(CONFIG_ARM64)
> +/*
> + * SPI vectors to use for vPCI; arch SPIs range is [32, 1019], but leaving a bit
> + * of room at the start to allow for SPIs to be specified through ACPI and
> + * starting with a power of two to satisfy power of 2 multi-MSI requirement.
> + */
> +#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_prepare NULL
> +
> +struct hv_pci_chip_data {
> + DECLARE_BITMAP(spi_map, HV_PCI_MSI_SPI_NR);
> + struct mutex map_lock;
> +};
> +
> +/* Hyper-V vPCI MSI GIC IRQ domain */
> +static struct irq_domain *hv_msi_gic_irq_domain;
> +
> +/* Hyper-V PCI MSI IRQ chip */
> +static struct irq_chip hv_arm64_msi_irq_chip = {
> + .name = "MSI",
> + .irq_set_affinity = irq_chip_set_affinity_parent,
> + .irq_eoi = irq_chip_eoi_parent,
> + .irq_mask = irq_chip_mask_parent,
> + .irq_unmask = irq_chip_unmask_parent
> +};
> +
> +static unsigned int hv_msi_get_int_vector(struct irq_data *irqd)
> +{
> + return irqd->parent_data->hwirq;
> +}
> +
> +static void hv_set_msi_entry_from_desc(union hv_msi_entry *msi_entry,
> + struct msi_desc *msi_desc)
> +{
> + msi_entry->address = ((u64)msi_desc->msg.address_hi << 32) |
> + msi_desc->msg.address_lo;
> + msi_entry->data = msi_desc->msg.data;
> +}
> +
> +static void hv_pci_vec_irq_domain_free(struct irq_domain *domain,
> + unsigned int virq, unsigned int nr_irqs)
> +{
> + struct hv_pci_chip_data *chip_data = domain->host_data;
> + struct irq_data *irqd = irq_domain_get_irq_data(domain, virq);
> + int first = irqd->hwirq - HV_PCI_MSI_SPI_START;
> +
> + mutex_lock(&chip_data->map_lock);
> + bitmap_release_region(chip_data->spi_map,
> + first,
> + get_count_order(nr_irqs));
> + mutex_unlock(&chip_data->map_lock);
> + irq_domain_reset_irq_data(irqd);
> + irq_domain_free_irqs_parent(domain, virq, nr_irqs);
> +}
> +
> +static int hv_pci_vec_alloc_device_irq(struct irq_domain *domain,
> + unsigned int nr_irqs,
> + irq_hw_number_t *hwirq)
> +{
> + struct hv_pci_chip_data *chip_data = domain->host_data;
> + unsigned int index;
> +
> + /* Find and allocate region from the SPI bitmap */
> + mutex_lock(&chip_data->map_lock);
> + index = bitmap_find_free_region(chip_data->spi_map,
> + HV_PCI_MSI_SPI_NR,
> + get_count_order(nr_irqs));
> + mutex_unlock(&chip_data->map_lock);
> + if (index < 0)
> + return -ENOSPC;
> +
> + *hwirq = index + HV_PCI_MSI_SPI_START;
> +
> + return 0;
> +}
> +
> +static int hv_pci_vec_irq_gic_domain_alloc(struct irq_domain *domain,
> + unsigned int virq,
> + irq_hw_number_t hwirq)
> +{
> + struct irq_fwspec fwspec;
> +
> + fwspec.fwnode = domain->parent->fwnode;
> + fwspec.param_count = 2;
> + fwspec.param[0] = hwirq;
> + fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
> +
> + return irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
> +}
> +
> +static int hv_pci_vec_irq_domain_alloc(struct irq_domain *domain,
> + unsigned int virq, unsigned int nr_irqs,
> + void *args)
> +{
> + irq_hw_number_t hwirq;
> + unsigned int i;
> + int ret;
> +
> + ret = hv_pci_vec_alloc_device_irq(domain, nr_irqs, &hwirq);
> + if (ret)
> + return ret;
> +
> + for (i = 0; i < nr_irqs; i++) {
> + ret = hv_pci_vec_irq_gic_domain_alloc(domain, virq + i,
> + hwirq + i);
> + if (ret)
> + goto free_irq;
> +
> + ret = irq_domain_set_hwirq_and_chip(domain, virq + i,
> + hwirq + i,
> + &hv_arm64_msi_irq_chip,
> + domain->host_data);
> + if (ret)
> + goto free_irq;
> +
> + pr_debug("pID:%d vID:%u\n", (int)(hwirq + i), virq + i);
> + }
> +
> + return 0;
> +
> +free_irq:
> + hv_pci_vec_irq_domain_free(domain, virq, nr_irqs);
> +
> + return ret;
> +}
> +
> +/*
> + * Pick the first online cpu as the irq affinity that can be temporarily used
> + * for composing MSI from the hypervisor. GIC will eventually set the right
> + * affinity for the irq and the 'unmask' will retarget the interrupt to that
> + * cpu.
> + */
> +static int hv_pci_vec_irq_domain_activate(struct irq_domain *domain,
> + struct irq_data *irqd, bool reserve)
> +{
> + int cpu = cpumask_first(cpu_online_mask);
> +
> + irq_data_update_effective_affinity(irqd, cpumask_of(cpu));
> +
> + return 0;
> +}
> +
> +static const struct irq_domain_ops hv_pci_domain_ops = {
> + .alloc = hv_pci_vec_irq_domain_alloc,
> + .free = hv_pci_vec_irq_domain_free,
> + .activate = hv_pci_vec_irq_domain_activate,
> +};
> +
> +static int hv_pci_irqchip_init(void)
> +{
> + static struct hv_pci_chip_data *chip_data;
> + struct fwnode_handle *fn = NULL;
> + int ret = -ENOMEM;
> +
> + chip_data = kzalloc(sizeof(*chip_data), GFP_KERNEL);
> + if (!chip_data)
> + return ret;
> +
> + mutex_init(&chip_data->map_lock);
> + fn = irq_domain_alloc_named_fwnode("Hyper-V ARM64 vPCI");
> + if (!fn)
> + goto free_chip;
> +
> + /*
> + * IRQ domain once enabled, should not be removed since there is no
> + * way to ensure that all the corresponding devices are also gone and
> + * no interrupts will be generated.
> + */
> + hv_msi_gic_irq_domain = acpi_irq_create_hierarchy(0, HV_PCI_MSI_SPI_NR,
> + fn, &hv_pci_domain_ops,
> + chip_data);
> +
> + if (!hv_msi_gic_irq_domain) {
> + pr_err("Failed to create Hyper-V ARMV vPCI MSI IRQ domain\n");
Typo in the above error message: "ARMV" should be "ARM64".
> + goto free_chip;
> + }
> +
> + return 0;
> +
> +free_chip:
> + kfree(chip_data);
> + if (fn)
> + irq_domain_free_fwnode(fn);
> +
> + return ret;
> +}
> +
> +static struct irq_domain *hv_pci_get_root_domain(void)
> +{
> + return hv_msi_gic_irq_domain;
> +}
> +#endif //CONFIG_ARM64
Use "C" style comments.
Michael
