[PATCH] irqchip/sifive-plic: Probe plic driver early for Allwinner D1 platform
Anup Patel
apatel at ventanamicro.com
Fri Aug 16 09:28:28 PDT 2024
Hi All,
On Fri, Aug 16, 2024 at 9:48 PM Anup Patel <apatel at ventanamicro.com> wrote:
>
> The latest Linux RISC-V no longer boots on the Allwinner D1 platform
> because the sun4i_timer driver fails to get an interrupt from PLIC.
>
> The real fix requires enabling the SBI time extension in the platform
> firmware (OpenSBI) and convert sun4i_timer into platform driver.
> Unfortunately, the real fix involves changing multiple places and
> can't be achieved in a short duration.
>
> As a work-around, retrofit plic probing such that plic is probed
> early only for the Allwinner D1 platform and probed as a regular
> platform driver for rest of the RISC-V platforms. In the process,
> partially revert some of the previous patches because PLIC device
> pointer is not available in all probing paths.
>
> More detailed discussion can found here:
> https://lore.kernel.org/lkml/20240814145642.344485-1-emil.renner.berthing@canonical.com/
>
> Fixes: e306a894bd51 ("irqchip/sifive-plic: Chain to parent IRQ after handlers are ready")
> Fixes: 8ec99b033147 ("irqchip/sifive-plic: Convert PLIC driver into a platform driver")
> Suggested-by: Thomas Gleixner <tglx at linutronix.de>
> Signed-off-by: Anup Patel <apatel at ventanamicro.com>
> ---
I don't have the Allwinner D1 platform so it would be great if someone
can test this patch on Allwinner D1.
Regards,
Anup
> drivers/irqchip/irq-sifive-plic.c | 128 +++++++++++++++++++-----------
> 1 file changed, 80 insertions(+), 48 deletions(-)
>
> diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c
> index 9e22f7e378f5..357d25662718 100644
> --- a/drivers/irqchip/irq-sifive-plic.c
> +++ b/drivers/irqchip/irq-sifive-plic.c
> @@ -3,6 +3,7 @@
> * Copyright (C) 2017 SiFive
> * Copyright (C) 2018 Christoph Hellwig
> */
> +#define pr_fmt(fmt) "riscv-plic: " fmt
> #include <linux/cpu.h>
> #include <linux/interrupt.h>
> #include <linux/io.h>
> @@ -63,7 +64,7 @@
> #define PLIC_QUIRK_EDGE_INTERRUPT 0
>
> struct plic_priv {
> - struct device *dev;
> + struct fwnode_handle *fwnode;
> struct cpumask lmask;
> struct irq_domain *irqdomain;
> void __iomem *regs;
> @@ -378,8 +379,8 @@ static void plic_handle_irq(struct irq_desc *desc)
> int err = generic_handle_domain_irq(handler->priv->irqdomain,
> hwirq);
> if (unlikely(err)) {
> - dev_warn_ratelimited(handler->priv->dev,
> - "can't find mapping for hwirq %lu\n", hwirq);
> + pr_warn_ratelimited("%pfwP: can't find mapping for hwirq %lu\n",
> + handler->priv->fwnode, hwirq);
> }
> }
>
> @@ -408,15 +409,14 @@ static int plic_starting_cpu(unsigned int cpu)
> enable_percpu_irq(plic_parent_irq,
> irq_get_trigger_type(plic_parent_irq));
> else
> - dev_warn(handler->priv->dev, "cpu%d: parent irq not available\n", cpu);
> + pr_warn("%pfwP: cpu%d: parent irq not available\n",
> + handler->priv->fwnode, cpu);
> plic_set_threshold(handler, PLIC_ENABLE_THRESHOLD);
>
> return 0;
> }
>
> -static const struct of_device_id plic_match[] = {
> - { .compatible = "sifive,plic-1.0.0" },
> - { .compatible = "riscv,plic0" },
> +static const struct of_device_id plic_quirks_match[] = {
> { .compatible = "andestech,nceplic100",
> .data = (const void *)BIT(PLIC_QUIRK_EDGE_INTERRUPT) },
> { .compatible = "thead,c900-plic",
> @@ -424,38 +424,36 @@ static const struct of_device_id plic_match[] = {
> {}
> };
>
> -static int plic_parse_nr_irqs_and_contexts(struct platform_device *pdev,
> +static int plic_parse_nr_irqs_and_contexts(struct fwnode_handle *fwnode,
> u32 *nr_irqs, u32 *nr_contexts)
> {
> - struct device *dev = &pdev->dev;
> int rc;
>
> /*
> * Currently, only OF fwnode is supported so extend this
> * function for ACPI support.
> */
> - if (!is_of_node(dev->fwnode))
> + if (!is_of_node(fwnode))
> return -EINVAL;
>
> - rc = of_property_read_u32(to_of_node(dev->fwnode), "riscv,ndev", nr_irqs);
> + rc = of_property_read_u32(to_of_node(fwnode), "riscv,ndev", nr_irqs);
> if (rc) {
> - dev_err(dev, "riscv,ndev property not available\n");
> + pr_err("%pfwP: riscv,ndev property not available\n", fwnode);
> return rc;
> }
>
> - *nr_contexts = of_irq_count(to_of_node(dev->fwnode));
> + *nr_contexts = of_irq_count(to_of_node(fwnode));
> if (WARN_ON(!(*nr_contexts))) {
> - dev_err(dev, "no PLIC context available\n");
> + pr_err("%pfwP: no PLIC context available\n", fwnode);
> return -EINVAL;
> }
>
> return 0;
> }
>
> -static int plic_parse_context_parent(struct platform_device *pdev, u32 context,
> +static int plic_parse_context_parent(struct fwnode_handle *fwnode, u32 context,
> u32 *parent_hwirq, int *parent_cpu)
> {
> - struct device *dev = &pdev->dev;
> struct of_phandle_args parent;
> unsigned long hartid;
> int rc;
> @@ -464,10 +462,10 @@ static int plic_parse_context_parent(struct platform_device *pdev, u32 context,
> * Currently, only OF fwnode is supported so extend this
> * function for ACPI support.
> */
> - if (!is_of_node(dev->fwnode))
> + if (!is_of_node(fwnode))
> return -EINVAL;
>
> - rc = of_irq_parse_one(to_of_node(dev->fwnode), context, &parent);
> + rc = of_irq_parse_one(to_of_node(fwnode), context, &parent);
> if (rc)
> return rc;
>
> @@ -480,48 +478,55 @@ static int plic_parse_context_parent(struct platform_device *pdev, u32 context,
> return 0;
> }
>
> -static int plic_probe(struct platform_device *pdev)
> +static int plic_probe(struct fwnode_handle *fwnode)
> {
> int error = 0, nr_contexts, nr_handlers = 0, cpu, i;
> - struct device *dev = &pdev->dev;
> unsigned long plic_quirks = 0;
> struct plic_handler *handler;
> u32 nr_irqs, parent_hwirq;
> struct plic_priv *priv;
> irq_hw_number_t hwirq;
> + void __iomem *regs;
>
> - if (is_of_node(dev->fwnode)) {
> + if (is_of_node(fwnode)) {
> const struct of_device_id *id;
>
> - id = of_match_node(plic_match, to_of_node(dev->fwnode));
> + id = of_match_node(plic_quirks_match, to_of_node(fwnode));
> if (id)
> plic_quirks = (unsigned long)id->data;
> +
> + regs = of_iomap(to_of_node(fwnode), 0);
> + if (!regs)
> + return -ENOMEM;
> + } else {
> + return -ENODEV;
> }
>
> - error = plic_parse_nr_irqs_and_contexts(pdev, &nr_irqs, &nr_contexts);
> + error = plic_parse_nr_irqs_and_contexts(fwnode, &nr_irqs, &nr_contexts);
> if (error)
> - return error;
> + goto fail_free_regs;
>
> - priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> - if (!priv)
> - return -ENOMEM;
> + priv = kzalloc(sizeof(*priv), GFP_KERNEL);
> + if (!priv) {
> + error = -ENOMEM;
> + goto fail_free_regs;
> + }
>
> - priv->dev = dev;
> + priv->fwnode = fwnode;
> priv->plic_quirks = plic_quirks;
> priv->nr_irqs = nr_irqs;
> + priv->regs = regs;
>
> - priv->regs = devm_platform_ioremap_resource(pdev, 0);
> - if (WARN_ON(!priv->regs))
> - return -EIO;
> -
> - priv->prio_save = devm_bitmap_zalloc(dev, nr_irqs, GFP_KERNEL);
> - if (!priv->prio_save)
> - return -ENOMEM;
> + priv->prio_save = bitmap_zalloc(nr_irqs, GFP_KERNEL);
> + if (!priv->prio_save) {
> + error = -ENOMEM;
> + goto fail_free_priv;
> + }
>
> for (i = 0; i < nr_contexts; i++) {
> - error = plic_parse_context_parent(pdev, i, &parent_hwirq, &cpu);
> + error = plic_parse_context_parent(fwnode, i, &parent_hwirq, &cpu);
> if (error) {
> - dev_warn(dev, "hwirq for context%d not found\n", i);
> + pr_warn("%pfwP: hwirq for context%d not found\n", fwnode, i);
> continue;
> }
>
> @@ -543,7 +548,7 @@ static int plic_probe(struct platform_device *pdev)
> }
>
> if (cpu < 0) {
> - dev_warn(dev, "Invalid cpuid for context %d\n", i);
> + pr_warn("%pfwP: Invalid cpuid for context %d\n", fwnode, i);
> continue;
> }
>
> @@ -554,7 +559,8 @@ static int plic_probe(struct platform_device *pdev)
> */
> handler = per_cpu_ptr(&plic_handlers, cpu);
> if (handler->present) {
> - dev_warn(dev, "handler already present for context %d.\n", i);
> + pr_warn("%pfwP: handler already present for context %d.\n",
> + fwnode, i);
> plic_set_threshold(handler, PLIC_DISABLE_THRESHOLD);
> goto done;
> }
> @@ -568,8 +574,8 @@ static int plic_probe(struct platform_device *pdev)
> i * CONTEXT_ENABLE_SIZE;
> handler->priv = priv;
>
> - handler->enable_save = devm_kcalloc(dev, DIV_ROUND_UP(nr_irqs, 32),
> - sizeof(*handler->enable_save), GFP_KERNEL);
> + handler->enable_save = kcalloc(DIV_ROUND_UP(nr_irqs, 32),
> + sizeof(*handler->enable_save), GFP_KERNEL);
> if (!handler->enable_save)
> goto fail_cleanup_contexts;
> done:
> @@ -581,7 +587,7 @@ static int plic_probe(struct platform_device *pdev)
> nr_handlers++;
> }
>
> - priv->irqdomain = irq_domain_add_linear(to_of_node(dev->fwnode), nr_irqs + 1,
> + priv->irqdomain = irq_domain_add_linear(to_of_node(fwnode), nr_irqs + 1,
> &plic_irqdomain_ops, priv);
> if (WARN_ON(!priv->irqdomain))
> goto fail_cleanup_contexts;
> @@ -619,13 +625,13 @@ static int plic_probe(struct platform_device *pdev)
> }
> }
>
> - dev_info(dev, "mapped %d interrupts with %d handlers for %d contexts.\n",
> - nr_irqs, nr_handlers, nr_contexts);
> + pr_info("%pfwP: mapped %d interrupts with %d handlers for %d contexts.\n",
> + fwnode, nr_irqs, nr_handlers, nr_contexts);
> return 0;
>
> fail_cleanup_contexts:
> for (i = 0; i < nr_contexts; i++) {
> - if (plic_parse_context_parent(pdev, i, &parent_hwirq, &cpu))
> + if (plic_parse_context_parent(fwnode, i, &parent_hwirq, &cpu))
> continue;
> if (parent_hwirq != RV_IRQ_EXT || cpu < 0)
> continue;
> @@ -634,17 +640,43 @@ static int plic_probe(struct platform_device *pdev)
> handler->present = false;
> handler->hart_base = NULL;
> handler->enable_base = NULL;
> + kfree(handler->enable_save);
> handler->enable_save = NULL;
> handler->priv = NULL;
> }
> - return -ENOMEM;
> + bitmap_free(priv->prio_save);
> +fail_free_priv:
> + kfree(priv);
> +fail_free_regs:
> + iounmap(regs);
> + return error;
> +}
> +
> +static int plic_platform_probe(struct platform_device *pdev)
> +{
> + return plic_probe(pdev->dev.fwnode);
> }
>
> +static const struct of_device_id plic_platform_match[] = {
> + { .compatible = "sifive,plic-1.0.0" },
> + { .compatible = "riscv,plic0" },
> + { .compatible = "andestech,nceplic100" },
> + {}
> +};
> +
> static struct platform_driver plic_driver = {
> .driver = {
> .name = "riscv-plic",
> - .of_match_table = plic_match,
> + .of_match_table = plic_platform_match,
> },
> - .probe = plic_probe,
> + .probe = plic_platform_probe,
> };
> builtin_platform_driver(plic_driver);
> +
> +static int __init plic_early_probe(struct device_node *node,
> + struct device_node *parent)
> +{
> + return plic_probe(&node->fwnode);
> +}
> +
> +IRQCHIP_DECLARE(riscv, "thead,c900-plic", plic_early_probe);
> --
> 2.34.1
>
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