Currently, the implementation of the RISC-V INTC driver uses the interrupt cause as the hardware interrupt number, with a maximum of 64 interrupts. However, the platform can expand the interrupt number further for custom local interrupts. To fully utilize the available local interrupt sources, switch to using irq_domain_create_tree() that creates the radix tree map, add global variables (riscv_intc_nr_irqs, riscv_intc_custom_base and riscv_intc_custom_nr_irqs) to determine the valid range of local interrupt number (hwirq). Signed-off-by: Yu Chien Peter Lin <peterlin@xxxxxxxxxxxxx> Reviewed-by: Randolph <randolph@xxxxxxxxxxxxx> --- Changes v1 -> v2: - Fixed irq mapping failure checking (suggested by Clément and Anup) Changes v2 -> v3: - No change Changes v3 -> v4: (Suggested by Thomas [1]) - Use pr_warn_ratelimited instead - Fix coding style and commit message Changes v4 -> v5: (Suggested by Thomas) - Fix commit message Changes v5 -> v6: (Suggested by Anup [2]) - Add riscv_intc_* global variables for checking range in riscv_intc_domain_alloc() - Advertise the number of interrupts allowed [1] https://patchwork.kernel.org/project/linux-riscv/patch/20231023004100.2663486-3-peterlin@xxxxxxxxxxxxx/#25573085 [2] https://patchwork.kernel.org/project/linux-riscv/patch/20231213070301.1684751-3-peterlin@xxxxxxxxxxxxx/#25636589 --- drivers/irqchip/irq-riscv-intc.c | 31 ++++++++++++++++++++++++------- 1 file changed, 24 insertions(+), 7 deletions(-) diff --git a/drivers/irqchip/irq-riscv-intc.c b/drivers/irqchip/irq-riscv-intc.c index e8d01b14ccdd..e1d80cb0020e 100644 --- a/drivers/irqchip/irq-riscv-intc.c +++ b/drivers/irqchip/irq-riscv-intc.c @@ -19,15 +19,17 @@ #include <linux/smp.h> static struct irq_domain *intc_domain; +static unsigned int riscv_intc_nr_irqs __ro_after_init; +static unsigned int riscv_intc_custom_base __ro_after_init; +static unsigned int riscv_intc_custom_nr_irqs __ro_after_init; static asmlinkage void riscv_intc_irq(struct pt_regs *regs) { unsigned long cause = regs->cause & ~CAUSE_IRQ_FLAG; - if (unlikely(cause >= BITS_PER_LONG)) - panic("unexpected interrupt cause"); - - generic_handle_domain_irq(intc_domain, cause); + if (generic_handle_domain_irq(intc_domain, cause)) + pr_warn_ratelimited("Failed to handle interrupt (cause: %ld)\n", + cause); } /* @@ -93,6 +95,14 @@ static int riscv_intc_domain_alloc(struct irq_domain *domain, if (ret) return ret; + /* + * Only allow hwirq for which we have corresponding standard or + * custom interrupt enable register. + */ + if ((riscv_intc_nr_irqs <= hwirq && hwirq < riscv_intc_custom_base) || + (riscv_intc_custom_base + riscv_intc_custom_nr_irqs) <= hwirq) + return -EINVAL; + for (i = 0; i < nr_irqs; i++) { ret = riscv_intc_domain_map(domain, virq + i, hwirq + i); if (ret) @@ -117,8 +127,7 @@ static int __init riscv_intc_init_common(struct fwnode_handle *fn) { int rc; - intc_domain = irq_domain_create_linear(fn, BITS_PER_LONG, - &riscv_intc_domain_ops, NULL); + intc_domain = irq_domain_create_tree(fn, &riscv_intc_domain_ops, NULL); if (!intc_domain) { pr_err("unable to add IRQ domain\n"); return -ENXIO; @@ -132,7 +141,11 @@ static int __init riscv_intc_init_common(struct fwnode_handle *fn) riscv_set_intc_hwnode_fn(riscv_intc_hwnode); - pr_info("%d local interrupts mapped\n", BITS_PER_LONG); + pr_info("%d local interrupts mapped\n", riscv_intc_nr_irqs); + if (riscv_intc_custom_nr_irqs) + pr_info("%d (%d - %d) custom local interrupts mapped\n", + riscv_intc_custom_nr_irqs, riscv_intc_custom_base, + riscv_intc_custom_base + riscv_intc_custom_nr_irqs); return 0; } @@ -166,6 +179,10 @@ static int __init riscv_intc_init(struct device_node *node, return 0; } + riscv_intc_nr_irqs = BITS_PER_LONG; + riscv_intc_custom_base = riscv_intc_nr_irqs; + riscv_intc_custom_nr_irqs = 0; + return riscv_intc_init_common(of_node_to_fwnode(node)); } -- 2.34.1
