On 22/06/18 16:14, Miquel Raynal wrote:
> This is a cascaded interrupt controller in the AP806 GIC that collapses
> SEIs (System Error Interrupt) coming from the AP and the CPs (through
> the ICU).
>
> The SEI handles up to 64 interrupts. The first 21 interrupts are wired
> from the AP. The next 43 interrupts are from the CPs and are triggered
> through MSI messages. To handle this complexity, the driver has to
> declare to the upper layer: one IRQ domain for the wired interrupts,
> one IRQ domain for the MSIs; and acts as a MSI controller ('parent')
> by declaring an MSI domain.
>
> Suggested-by: Haim Boot <hayim@xxxxxxxxxxx>
> Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
> ---
> drivers/irqchip/Kconfig | 3 +
> drivers/irqchip/Makefile | 1 +
> drivers/irqchip/irq-mvebu-sei.c | 444 ++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 448 insertions(+)
> create mode 100644 drivers/irqchip/irq-mvebu-sei.c
>
> diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> index e9233db16e03..922e2a919cf3 100644
> --- a/drivers/irqchip/Kconfig
> +++ b/drivers/irqchip/Kconfig
> @@ -310,6 +310,9 @@ config MVEBU_ODMI
> config MVEBU_PIC
> bool
>
> +config MVEBU_SEI
> + bool
> +
> config LS_SCFG_MSI
> def_bool y if SOC_LS1021A || ARCH_LAYERSCAPE
> depends on PCI && PCI_MSI
> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> index 15f268f646bf..69d2ccb454ef 100644
> --- a/drivers/irqchip/Makefile
> +++ b/drivers/irqchip/Makefile
> @@ -76,6 +76,7 @@ obj-$(CONFIG_MVEBU_GICP) += irq-mvebu-gicp.o
> obj-$(CONFIG_MVEBU_ICU) += irq-mvebu-icu.o
> obj-$(CONFIG_MVEBU_ODMI) += irq-mvebu-odmi.o
> obj-$(CONFIG_MVEBU_PIC) += irq-mvebu-pic.o
> +obj-$(CONFIG_MVEBU_SEI) += irq-mvebu-sei.o
> obj-$(CONFIG_LS_SCFG_MSI) += irq-ls-scfg-msi.o
> obj-$(CONFIG_EZNPS_GIC) += irq-eznps.o
> obj-$(CONFIG_ARCH_ASPEED) += irq-aspeed-vic.o irq-aspeed-i2c-ic.o
> diff --git a/drivers/irqchip/irq-mvebu-sei.c b/drivers/irqchip/irq-mvebu-sei.c
> new file mode 100644
> index 000000000000..4a62cd2385d7
> --- /dev/null
> +++ b/drivers/irqchip/irq-mvebu-sei.c
> @@ -0,0 +1,444 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +#define pr_fmt(fmt) "mvebu-sei: " fmt
> +
> +#include <linux/irq.h>
> +#include <linux/interrupt.h>
> +#include <linux/irqchip/chained_irq.h>
> +#include <linux/irqdomain.h>
> +#include <linux/kernel.h>
> +#include <linux/of_address.h>
> +#include <linux/of_irq.h>
> +#include <linux/of_platform.h>
> +#include <linux/msi.h>
> +#include <linux/platform_device.h>
> +#include <linux/irqchip.h>
> +
> +#include <dt-bindings/interrupt-controller/arm-gic.h>
> +
> +/* Cause register */
> +#define GICP_SECR(idx) (0x0 + ((idx) * 0x4))
> +/* Mask register */
> +#define GICP_SEMR(idx) (0x20 + ((idx) * 0x4))
> +#define GICP_SET_SEI_OFFSET 0x30
> +
> +#define SEI_IRQ_COUNT_PER_REG 32
> +#define SEI_IRQ_REG_COUNT 2
> +#define SEI_IRQ_COUNT (SEI_IRQ_COUNT_PER_REG * SEI_IRQ_REG_COUNT)
> +#define SEI_IRQ_REG_IDX(irq_id) ((irq_id) / SEI_IRQ_COUNT_PER_REG)
> +#define SEI_IRQ_REG_BIT(irq_id) ((irq_id) % SEI_IRQ_COUNT_PER_REG)
> +
> +struct mvebu_sei_interrupt_range {
> + u32 first;
> + u32 number;
nit: number is a bit vague. consider using size (or anything similar).
> +};
> +
> +struct mvebu_sei {
> + struct device *dev;
> + void __iomem *base;
> + struct resource *res;
> + struct irq_domain *ap_domain;
> + struct irq_domain *cp_domain;
> + struct mvebu_sei_interrupt_range ap_interrupts;
> + struct mvebu_sei_interrupt_range cp_interrupts;
> + /* Lock on MSI allocations/releases */
> + struct mutex cp_msi_lock;
> + DECLARE_BITMAP(cp_msi_bitmap, SEI_IRQ_COUNT);
> +};
> +
> +static int mvebu_sei_domain_to_sei_irq(struct mvebu_sei *sei,
> + struct irq_domain *domain,
> + irq_hw_number_t hwirq)
> +{
> + if (domain == sei->ap_domain)
> + return sei->ap_interrupts.first + hwirq;
> + else
> + return sei->cp_interrupts.first + hwirq;
> +}
> +
> +static void mvebu_sei_reset(struct mvebu_sei *sei)
> +{
> + u32 reg_idx;
> +
> + /* Clear IRQ cause registers */
> + for (reg_idx = 0; reg_idx < SEI_IRQ_REG_COUNT; reg_idx++)
> + writel(0xFFFFFFFF, sei->base + GICP_SECR(reg_idx));
> +}
> +
> +static void mvebu_sei_mask_irq(struct irq_data *d)
> +{
> + struct mvebu_sei *sei = irq_data_get_irq_chip_data(d);
> + u32 sei_irq = mvebu_sei_domain_to_sei_irq(sei, d->domain, d->hwirq);
> + u32 reg_idx = SEI_IRQ_REG_IDX(sei_irq);
> + u32 reg;
> +
> + /* 1 disables the interrupt */
> + reg = readl(sei->base + GICP_SEMR(reg_idx));
> + reg |= BIT(SEI_IRQ_REG_BIT(sei_irq));
> + writel(reg, sei->base + GICP_SEMR(reg_idx));
Consider using _relaxed accessors, unless this relies on ordering with
other memory accesses (I really don't think it does).
> +}
> +
> +static void mvebu_sei_unmask_irq(struct irq_data *d)
> +{
> + struct mvebu_sei *sei = irq_data_get_irq_chip_data(d);
> + u32 sei_irq = mvebu_sei_domain_to_sei_irq(sei, d->domain, d->hwirq);
> + u32 reg_idx = SEI_IRQ_REG_IDX(sei_irq);
> + u32 reg;
> +
> + /* 0 enables the interrupt */
> + reg = readl(sei->base + GICP_SEMR(reg_idx));
> + reg &= ~BIT(SEI_IRQ_REG_BIT(sei_irq));
> + writel(reg, sei->base + GICP_SEMR(reg_idx));
> +}
> +
> +static void mvebu_sei_compose_msi_msg(struct irq_data *data,
> + struct msi_msg *msg)
> +{
> + struct mvebu_sei *sei = data->chip_data;
> + phys_addr_t set = sei->res->start + GICP_SET_SEI_OFFSET;
> +
> + msg->data = mvebu_sei_domain_to_sei_irq(sei, data->domain, data->hwirq);
> + msg->address_lo = lower_32_bits(set);
> + msg->address_hi = upper_32_bits(set);
> +}
> +
> +static int mvebu_sei_ap_set_type(struct irq_data *data, unsigned int type)
> +{
> + if (!(type & IRQ_TYPE_LEVEL_HIGH))
> + return -EINVAL;
> +
> + return 0;
> +}
> +
> +static int mvebu_sei_cp_set_type(struct irq_data *data, unsigned int type)
> +{
> + if (!(type & IRQ_TYPE_EDGE_RISING))
> + return -EINVAL;
> +
> + return 0;
> +}
> +
> +static struct irq_chip mvebu_sei_ap_wired_irq_chip = {
> + .name = "AP wired SEI",
> + .irq_mask = mvebu_sei_mask_irq,
> + .irq_unmask = mvebu_sei_unmask_irq,
> + .irq_eoi = irq_chip_eoi_parent,
> + .irq_set_affinity = irq_chip_set_affinity_parent,
> + .irq_set_type = mvebu_sei_ap_set_type,
> +};
> +
> +static struct irq_chip mvebu_sei_cp_msi_irq_chip = {
> + .name = "CP MSI SEI",
> + .irq_mask = mvebu_sei_mask_irq,
> + .irq_unmask = mvebu_sei_unmask_irq,
> + .irq_eoi = irq_chip_eoi_parent,
> + .irq_set_affinity = irq_chip_set_affinity_parent,
> + .irq_set_type = mvebu_sei_cp_set_type,
> + .irq_compose_msi_msg = mvebu_sei_compose_msi_msg,
> +};
> +
> +static int mvebu_sei_irq_domain_alloc(struct irq_domain *domain,
> + unsigned int virq, unsigned int nr_irqs,
> + void *args)
> +{
> + struct mvebu_sei *sei = domain->host_data;
> + struct irq_fwspec *fwspec = args;
> + struct irq_chip *irq_chip;
> + int sei_hwirq, hwirq;
> + int ret;
> +
> + /* The software only supports single allocations for now */
> + if (nr_irqs != 1)
> + return -ENOTSUPP;
> +
> + if (domain == sei->ap_domain) {
> + irq_chip = &mvebu_sei_ap_wired_irq_chip;
> + hwirq = fwspec->param[0];
> + } else {
> + irq_chip = &mvebu_sei_cp_msi_irq_chip;
> + mutex_lock(&sei->cp_msi_lock);
> + hwirq = bitmap_find_free_region(sei->cp_msi_bitmap,
> + sei->cp_interrupts.number, 0);
> + mutex_unlock(&sei->cp_msi_lock);
> + if (hwirq < 0)
> + return -ENOSPC;
> + }
> +
> + sei_hwirq = mvebu_sei_domain_to_sei_irq(sei, domain, hwirq);
> +
> + fwspec->fwnode = domain->parent->fwnode;
> + fwspec->param_count = 3;
> + fwspec->param[0] = GIC_SPI;
> + fwspec->param[1] = sei_hwirq;
> + fwspec->param[2] = IRQ_TYPE_EDGE_RISING;
> +
> + ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, fwspec);
> + if (ret)
> + goto release_region;
> +
> + ret = irq_domain_set_hwirq_and_chip(domain, virq, hwirq, irq_chip, sei);
> + if (ret)
> + goto free_irq_parents;
> +
> + return 0;
> +
> +free_irq_parents:
> + irq_domain_free_irqs_parent(domain, virq, nr_irqs);
> +release_region:
> + if (domain == sei->cp_domain) {
> + mutex_lock(&sei->cp_msi_lock);
> + bitmap_release_region(sei->cp_msi_bitmap, hwirq, 0);
> + mutex_unlock(&sei->cp_msi_lock);
> + }
> +
> + return ret;
> +}
> +
> +static void mvebu_sei_irq_domain_free(struct irq_domain *domain,
> + unsigned int virq, unsigned int nr_irqs)
> +{
> + struct mvebu_sei *sei = domain->host_data;
> + struct irq_data *d = irq_domain_get_irq_data(domain, virq);
> + u32 irq_nb = sei->ap_interrupts.number + sei->cp_interrupts.number;
> +
> + if (nr_irqs != 1 || d->hwirq >= irq_nb) {
> + dev_err(sei->dev, "Invalid hwirq %lu\n", d->hwirq);
> + return;
> + }
> +
> + irq_domain_free_irqs_parent(domain, virq, nr_irqs);
> +
> + mutex_lock(&sei->cp_msi_lock);
> + bitmap_release_region(sei->cp_msi_bitmap, d->hwirq, 0);
> + mutex_unlock(&sei->cp_msi_lock);
> +}
> +
> +static int mvebu_sei_ap_match(struct irq_domain *d, struct device_node *node,
> + enum irq_domain_bus_token bus_token)
> +{
> + struct mvebu_sei *sei = d->host_data;
If you're dereferencing the domain here...
> +
> + if (!sei)
> + return 0;
> +
> + if (sei->dev->of_node != node)
> + return 0;
> +
> + if (!d || !sei->ap_domain)
... how can it be NULL here? Actually, how can it *ever* be NULL?
Also, it is not clear to me how can sei or sei->ap_domain be NULL.
> + return 0;
> +
> + if (d == sei->ap_domain)
> + return 1;
> +
> + return 0;
> +}
> +
> +static const struct irq_domain_ops mvebu_sei_ap_domain_ops = {
> + .match = mvebu_sei_ap_match,
> + .xlate = irq_domain_xlate_onecell,
> + .alloc = mvebu_sei_irq_domain_alloc,
> + .free = mvebu_sei_irq_domain_free,
> +};
> +
> +static const struct irq_domain_ops mvebu_sei_cp_domain_ops = {
> + .alloc = mvebu_sei_irq_domain_alloc,
> + .free = mvebu_sei_irq_domain_free,
> +};
> +
> +static struct irq_chip mvebu_sei_msi_irq_chip = {
> + .name = "SEI MSI controller",
> + .irq_set_type = mvebu_sei_cp_set_type,
> +};
> +
> +static struct msi_domain_ops mvebu_sei_msi_ops = {
> +};
> +
> +static struct msi_domain_info mvebu_sei_msi_domain_info = {
> + .flags = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS,
> + .ops = &mvebu_sei_msi_ops,
> + .chip = &mvebu_sei_msi_irq_chip,
> +};
> +
> +static void mvebu_sei_handle_cascade_irq(struct irq_desc *desc)
> +{
> + struct mvebu_sei *sei = irq_desc_get_handler_data(desc);
> + struct irq_chip *chip = irq_desc_get_chip(desc);
> + unsigned long irqmap, irq_bit;
> + u32 reg_idx, virq, irqn;
> +
> + chained_irq_enter(chip, desc);
> +
> + /* Read both SEI cause registers (64 bits) */
> + for (reg_idx = 0; reg_idx < SEI_IRQ_REG_COUNT; reg_idx++) {
> + irqmap = readl_relaxed(sei->base + GICP_SECR(reg_idx));
I think it'd be a lot clearer if you just read both 32bit registers and
treat the resulting 64bit quantity as a single bitmap, rather than
having this outer loop.
> +
> + /* Call handler for each set bit */
> + for_each_set_bit(irq_bit, &irqmap, SEI_IRQ_COUNT_PER_REG) {
> + /* Cause Register gives the SEI number */
> + irqn = irq_bit + reg_idx * SEI_IRQ_COUNT_PER_REG;
> + /*
> + * Finding Linux mapping (virq) needs the right domain
> + * and the relative hwirq (which start at 0 in both
> + * cases, while irqn is relative to all SEI interrupts).
> + */
> + if (irqn < sei->ap_interrupts.number) {
> + virq = irq_find_mapping(sei->ap_domain, irqn);
> + } else {
> + irqn -= sei->ap_interrupts.number;
> + virq = irq_find_mapping(sei->cp_domain, irqn);
> + }
> +
> + /* Call IRQ handler */
> + generic_handle_irq(virq);
> + }
> +
> + /* Clear interrupt indication by writing 1 to it */
> + writel(irqmap, sei->base + GICP_SECR(reg_idx));
write_relaxed. It would probably make sense not to write to that
register if no bits were set to 1 the first place.
> + }
> +
> + chained_irq_exit(chip, desc);
> +}
> +
> +static int mvebu_sei_probe(struct platform_device *pdev)
> +{
> + struct device_node *node = pdev->dev.of_node, *parent;
> + struct irq_domain *parent_domain, *plat_domain;
> + struct mvebu_sei *sei;
> + const __be32 *property;
> + u32 parent_irq, size;
> + int ret;
> +
> + sei = devm_kzalloc(&pdev->dev, sizeof(*sei), GFP_KERNEL);
> + if (!sei)
> + return -ENOMEM;
> +
> + sei->dev = &pdev->dev;
> +
> + mutex_init(&sei->cp_msi_lock);
> +
> + sei->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + sei->base = devm_ioremap_resource(sei->dev, sei->res);
> + if (!sei->base) {
> + dev_err(sei->dev, "Failed to remap SEI resource\n");
> + return -ENODEV;
> + }
> +
> + mvebu_sei_reset(sei);
> +
> + /*
> + * Reserve the single (top-level) parent SPI IRQ from which all the
> + * interrupts handled by this driver will be signaled.
> + */
> + parent_irq = irq_of_parse_and_map(node, 0);
> + if (parent_irq <= 0) {
> + dev_err(sei->dev, "Failed to retrieve top-level SPI IRQ\n");
> + return -ENODEV;
> + }
> +
> + irq_set_chained_handler(parent_irq, mvebu_sei_handle_cascade_irq);
> + irq_set_handler_data(parent_irq, sei);
> +
> + /*
> + * SEIs can be triggered from the AP through wired interrupts and from
> + * the CPs through MSIs.
> + */
> +
> + /* Get a reference to the parent domain to create a hierarchy */
> + parent = of_irq_find_parent(node);
> + if (!parent) {
> + dev_err(sei->dev, "Failed to find parent IRQ node\n");
> + ret = -ENODEV;
> + goto dispose_irq;
> + }
Wouldn't it make sense to check this before having configured things
with a chained handler? i.e. check everything that can be checked, and
once you have everything in order, do the plumbing?
> +
> + parent_domain = irq_find_host(parent);
> + if (!parent_domain) {
> + dev_err(sei->dev, "Failed to find parent IRQ domain\n");
> + ret = -ENODEV;
> + goto dispose_irq;
> + }
> +
> + /*
> + * Retrieve the IRQ organization (AP/CP): the index of the first one and
> + * the number of them for each domain.
> + */
> + property = of_get_property(node, "marvell,sei-ap-ranges", &size);
> + if (!property || (size != (2 * sizeof(u32)))) {
> + dev_err(sei->dev, "Missing 'marvell,sei-ap-ranges' property\n");
> + ret = -ENODEV;
> + goto dispose_irq;
> + }
> +
> + sei->ap_interrupts.first = be32_to_cpu(property[0]);
> + sei->ap_interrupts.number = be32_to_cpu(property[1]);
> +
> + property = of_get_property(node, "marvell,sei-cp-ranges", &size);
> + if (!property || (size != (2 * sizeof(u32)))) {
> + dev_err(sei->dev, "Missing 'marvell,sei-cp-ranges' property\n");
> + ret = -ENODEV;
> + goto dispose_irq;
> + }
> +
> + sei->cp_interrupts.first = be32_to_cpu(property[0]);
> + sei->cp_interrupts.number = be32_to_cpu(property[1]);
> +
> + /* Create the 'wired' hierarchy */
> + sei->ap_domain = irq_domain_create_hierarchy(parent_domain, 0,
> + sei->ap_interrupts.number,
> + of_node_to_fwnode(node),
> + &mvebu_sei_ap_domain_ops,
> + sei);
> + if (!sei->ap_domain) {
> + dev_err(sei->dev, "Failed to create AP IRQ domain\n");
> + ret = -ENOMEM;
> + goto dispose_irq;
> + }
> +
> + /* Create the 'MSI' hierarchy */
> + sei->cp_domain = irq_domain_create_hierarchy(parent_domain, 0,
> + sei->cp_interrupts.number,
> + of_node_to_fwnode(node),
> + &mvebu_sei_cp_domain_ops,
> + sei);
> + if (!sei->cp_domain) {
> + pr_err("Failed to create CPs IRQ domain\n");
> + ret = -ENOMEM;
> + goto remove_ap_domain;
> + }
> +
> + plat_domain = platform_msi_create_irq_domain(of_node_to_fwnode(node),
> + &mvebu_sei_msi_domain_info,
> + sei->cp_domain);
> + if (!plat_domain) {
> + pr_err("Failed to create CPs MSI domain\n");
> + ret = -ENOMEM;
> + goto remove_cp_domain;
> + }
> +
> + platform_set_drvdata(pdev, sei);
> +
> + return 0;
> +
> +remove_cp_domain:
> + irq_domain_remove(sei->cp_domain);
> +remove_ap_domain:
> + irq_domain_remove(sei->ap_domain);
> +dispose_irq:
> + irq_dispose_mapping(parent_irq);
> +
> + return ret;
> +}
> +
> +static const struct of_device_id mvebu_sei_of_match[] = {
> + { .compatible = "marvell,armada-8k-sei", },
> + {},
> +};
> +
> +static struct platform_driver mvebu_sei_driver = {
> + .probe = mvebu_sei_probe,
> + .driver = {
> + .name = "mvebu-sei",
> + .of_match_table = mvebu_sei_of_match,
> + },
> +};
> +builtin_platform_driver(mvebu_sei_driver);
>
Thanks,
M.
--
Jazz is not dead. It just smells funny...
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