On Thu, 3 Sep 2020 16:25:51 +0100
Marc Zyngier <maz@xxxxxxxxxx> wrote:
> Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
Few minor comments inline.
Thanks,
Jonathan
> ---
> drivers/irqchip/irq-rvid.c | 182 +++++++++++++++++++++++++++++++++++++
> 1 file changed, 182 insertions(+)
>
> diff --git a/drivers/irqchip/irq-rvid.c b/drivers/irqchip/irq-rvid.c
> index 953f654e58d4..250f95ad1a09 100644
> --- a/drivers/irqchip/irq-rvid.c
> +++ b/drivers/irqchip/irq-rvid.c
> @@ -12,12 +12,19 @@
> #include <linux/irq.h>
> #include <linux/irqchip.h>
> #include <linux/irqdomain.h>
> +#include <linux/msi.h>
>
> #include <linux/irqchip/irq-rvic.h>
>
> struct rvid_data {
> struct fwnode_handle *fwnode;
> struct irq_domain *domain;
> + struct irq_domain *msi_domain;
> + struct irq_domain *pci_domain;
> + unsigned long *msi_map;
> + struct mutex msi_lock;
> + u32 msi_base;
> + u32 msi_nr;
> };
>
> static struct rvid_data rvid;
> @@ -209,6 +216,177 @@ static const struct irq_domain_ops rvid_irq_domain_ops = {
> .deactivate = rvid_irq_domain_deactivate,
> };
>
> +#ifdef CONFIG_PCI_MSI
> +/*
> + * The MSI irqchip is completely transparent. The only purpose of the
> + * corresponding irq domain is to provide the MSI allocator, and feed
> + * the allocated inputs to the main rVID irq domain for mapping at the
> + * rVIC level.
> + */
> +static struct irq_chip rvid_msi_chip = {
> + .name = "rvid-MSI",
> + .irq_mask = irq_chip_mask_parent,
> + .irq_unmask = irq_chip_unmask_parent,
> + .irq_eoi = irq_chip_eoi_parent,
> + .irq_get_irqchip_state = irq_chip_get_parent_state,
> + .irq_set_irqchip_state = irq_chip_set_parent_state,
> + .irq_retrigger = irq_chip_retrigger_hierarchy,
> + .irq_set_type = irq_chip_set_type_parent,
> + .irq_set_affinity = irq_chip_set_affinity_parent,
> +};
> +
> +static int rvid_msi_domain_alloc(struct irq_domain *domain, unsigned int virq,
> + unsigned int nr_irqs, void *arg)
> +{
> + int ret, hwirq, i;
> +
> + mutex_lock(&rvid.msi_lock);
> + hwirq = bitmap_find_free_region(rvid.msi_map, rvid.msi_nr,
> + get_count_order(nr_irqs));
> + mutex_unlock(&rvid.msi_lock);
> +
> + if (hwirq < 0)
> + return -ENOSPC;
> +
> + for (i = 0; i < nr_irqs; i++) {
> + /* Use the rVID domain to map the input to something */
> + struct irq_fwspec fwspec = (struct irq_fwspec) {
> + .fwnode = domain->parent->fwnode,
> + .param_count = 1,
> + .param[0] = rvid.msi_base + hwirq + i,
> + };
> +
> + ret = irq_domain_alloc_irqs_parent(domain, virq + i, 1, &fwspec);
> + if (WARN_ON(ret))
> + goto out;
> +
> + irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
> + &rvid_msi_chip, &rvid);
> + }
> +
> + return 0;
> +
> +out:
I missed this on previous patch, but doesn't the error path need to undo the
irq_domain_alloc_irqs_parent part? irq_domain_free_irqs_parent()
> + mutex_lock(&rvid.msi_lock);
> + bitmap_release_region(rvid.msi_map, hwirq, get_count_order(nr_irqs));
> + mutex_unlock(&rvid.msi_lock);
> +
> + return ret;
> +}
> +
> +static void rvid_msi_domain_free(struct irq_domain *domain, unsigned int virq,
> + unsigned int nr_irqs)
> +{
> + struct irq_data *d = irq_domain_get_irq_data(domain, virq);
> + irq_hw_number_t hwirq = d->hwirq;
> +
> + /* This is a bit cheeky, but hey, recursion never hurt anyone... */
> + rvid_irq_domain_free(domain, virq, nr_irqs);
> +
> + mutex_lock(&rvid.msi_lock);
> + bitmap_release_region(rvid.msi_map, hwirq, get_count_order(nr_irqs));
> + mutex_unlock(&rvid.msi_lock);
> +}
> +
> +static struct irq_domain_ops rvid_msi_domain_ops = {
> + .alloc = rvid_msi_domain_alloc,
> + .free = rvid_msi_domain_free,
> +};
> +
> +/*
> + * The PCI irq chip only provides the minimal stuff, as most of the
> + * other methods will be provided as defaults.
> + */
> +static void rvid_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
> +{
> + /* Random address, the rVID doesn't really have a doorbell */
> + msg->address_hi = 0;
> + msg->address_lo = 0xba5e0000;
> +
> + /*
> + * We are called from the PCI domain, and what we program in
> + * the device is the rVID input pin, which is located two
> + * levels down in the interrupt chain (PCI -> MSI -> rVID).
> + */
> + msg->data = data->parent_data->parent_data->hwirq;
> +}
> +
> +static void rvid_pci_mask(struct irq_data *d)
> +{
> + pci_msi_mask_irq(d);
> + irq_chip_mask_parent(d);
> +}
> +
> +static void rvid_pci_unmask(struct irq_data *d)
> +{
> + pci_msi_unmask_irq(d);
> + irq_chip_unmask_parent(d);
> +}
> +
> +static struct irq_chip rvid_pci_chip = {
> + .name = "PCI-MSI",
> + .irq_mask = rvid_pci_mask,
> + .irq_unmask = rvid_pci_unmask,
> + .irq_eoi = irq_chip_eoi_parent,
> + .irq_compose_msi_msg = rvid_compose_msi_msg,
> + .irq_write_msi_msg = pci_msi_domain_write_msg,
> +};
> +
> +static struct msi_domain_info rvid_pci_domain_info = {
> + .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
> + MSI_FLAG_PCI_MSIX | MSI_FLAG_MULTI_PCI_MSI),
> + .chip = &rvid_pci_chip,
> +};
> +
> +static void __init rvid_msi_setup(struct device_node *np)
> +{
> + if (!of_property_read_bool(np, "msi-controller"))
> + return;
> +
> + if (of_property_read_u32_index(np, "msi-range", 0, &rvid.msi_base) ||
> + of_property_read_u32_index(np, "msi-range", 1, &rvid.msi_nr)) {
Looks like msi-range isn't defined in any existing bindings, or my grep
fu is broken today.
> + pr_err("Invalid or missing msi-range\n");
> + return;
> + }
> +
> + mutex_init(&rvid.msi_lock);
> +
> + rvid.msi_map = bitmap_alloc(rvid.msi_nr, GFP_KERNEL | __GFP_ZERO);
bitmap_zalloc()
> + if (!rvid.msi_map)
> + return;
> +
> + rvid.msi_domain = irq_domain_create_hierarchy(rvid.domain, 0, 0,
> + rvid.fwnode,
> + &rvid_msi_domain_ops,
> + &rvid);
> + if (!rvid.msi_domain) {
> + pr_err("Failed to allocate MSI domain\n");
> + goto out;
> + }
> +
> + irq_domain_update_bus_token(rvid.msi_domain, DOMAIN_BUS_NEXUS);
> +
> + rvid.pci_domain = pci_msi_create_irq_domain(rvid.domain->fwnode,
> + &rvid_pci_domain_info,
> + rvid.msi_domain);
> + if (!rvid.pci_domain) {
> + pr_err("Failed to allocate PCI domain\n");
> + goto out;
> + }
> +
> + pr_info("MSIs available as inputs [%d:%d]\n",
> + rvid.msi_base, rvid.msi_base + rvid.msi_nr - 1);
> + return;
> +
> +out:
> + if (rvid.msi_domain)
> + irq_domain_remove(rvid.msi_domain);
> + kfree(rvid.msi_map);
> +}
> +#else
> +static inline void rvid_msi_setup(struct device_node *np) {}
> +#endif
> +
> static int __init rvid_init(struct device_node *node,
> struct device_node *parent)
> {
> @@ -253,6 +431,10 @@ static int __init rvid_init(struct device_node *node,
> return -ENOMEM;
> }
>
> + irq_domain_update_bus_token(rvid.domain, DOMAIN_BUS_WIRED);
> +
> + rvid_msi_setup(node);
> +
> return 0;
> }
>
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