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>
Reviewed-by: Anup Patel <anup@xxxxxxxxxxxxxx>
Reviewed-by: Atish Patra <atishp@xxxxxxxxxxxx>
---
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 the range of valid
interrupt number in riscv_intc_domain_alloc()
- Advertise the number of interrupts allowed
Changes v6 -> v7:
- No functional change
Changes v7 -> v8:
- Include Reviewed-by tags from Anup and Atish
Changes v8 -> v9 (Suggested by Thomas [3]):
- Fix coding style
- Update hwirq range checks
- Update riscv_intc_* global variables initialization
[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
[3] https://patchwork.kernel.org/project/linux-riscv/patch/20240129092553.2058043-3-peterlin@xxxxxxxxxxxxx/#25710584
---
drivers/irqchip/irq-riscv-intc.c | 26 +++++++++++++++++++-------
1 file changed, 19 insertions(+), 7 deletions(-)
diff --git a/drivers/irqchip/irq-riscv-intc.c b/drivers/irqchip/irq-riscv-intc.c
index e8d01b14ccdd..684875c39728 100644
--- a/drivers/irqchip/irq-riscv-intc.c
+++ b/drivers/irqchip/irq-riscv-intc.c
@@ -19,15 +19,16 @@
#include <linux/smp.h>
static struct irq_domain *intc_domain;
+static unsigned int riscv_intc_nr_irqs __ro_after_init = BITS_PER_LONG;
+static unsigned int riscv_intc_custom_base __ro_after_init = BITS_PER_LONG;
+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 +94,14 @@ 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 ((hwirq >= riscv_intc_nr_irqs && hwirq < riscv_intc_custom_base) ||
+ (hwirq >= riscv_intc_custom_base + riscv_intc_custom_nr_irqs))
+ return -EINVAL;
+
for (i = 0; i < nr_irqs; i++) {
ret = riscv_intc_domain_map(domain, virq + i, hwirq + i);
if (ret)
@@ -117,8 +126,7 @@ 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 +140,11 @@ 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 custom local interrupts mapped\n",
+ riscv_intc_custom_nr_irqs);
+ }
return 0;
}
--
2.34.1
