[PATCH] alpha: marvel: Fix lock ordering in init_io7_irqs()

From: Matt Turner

Date: Fri Apr 03 2026 - 11:11:47 EST


Move irq_set_chip_and_handler() and irq_set_status_flags() calls
outside the io7->irq_lock raw spinlock. These functions take
sparse_irq_lock, which is a mutex, and taking a sleeping lock while
holding a raw spinlock is invalid. The raw spinlock only needs to
protect the hardware CSR accesses.

This fixes the following lockdep splat during boot:

[ BUG: Invalid wait context ]
swapper/0/0 is trying to lock:
sparse_irq_lock{....}-{4:4}, at: irq_mark_irq
other info that might help us debug this:
context-{5:5}
1 lock held by swapper/0/0:
#0: &io7->irq_lock{....}-{2:2}, at: init_io7_irqs.constprop.0

Assisted-by: Claude:claude-opus-4-6
Signed-off-by: Matt Turner <mattst88@xxxxxxxxx>
---
arch/alpha/kernel/sys_marvel.c | 27 +++++++++++++--------------
1 file changed, 13 insertions(+), 14 deletions(-)

diff --git ./arch/alpha/kernel/sys_marvel.c ./arch/alpha/kernel/sys_marvel.c
index 1f99b03effc2..d0bdd5e6cfd7 100644
--- ./arch/alpha/kernel/sys_marvel.c
+++ ./arch/alpha/kernel/sys_marvel.c
@@ -263,6 +263,18 @@ init_io7_irqs(struct io7 *io7,
*/
printk(" Interrupts reported to CPU at PE %u\n", boot_cpuid);

+ /* Set up the lsi irqs. */
+ for (i = 0; i < 128; ++i) {
+ irq_set_chip_and_handler(base + i, lsi_ops, handle_level_irq);
+ irq_set_status_flags(i, IRQ_LEVEL);
+ }
+
+ /* Set up the msi irqs. */
+ for (i = 128; i < (128 + 512); ++i) {
+ irq_set_chip_and_handler(base + i, msi_ops, handle_level_irq);
+ irq_set_status_flags(i, IRQ_LEVEL);
+ }
+
raw_spin_lock(&io7->irq_lock);

/* set up the error irqs */
@@ -272,26 +284,13 @@ init_io7_irqs(struct io7 *io7,
io7_redirect_irq(io7, &io7->csrs->STV_CTL.csr, boot_cpuid);
io7_redirect_irq(io7, &io7->csrs->HEI_CTL.csr, boot_cpuid);

- /* Set up the lsi irqs. */
- for (i = 0; i < 128; ++i) {
- irq_set_chip_and_handler(base + i, lsi_ops, handle_level_irq);
- irq_set_status_flags(i, IRQ_LEVEL);
- }
-
/* Disable the implemented irqs in hardware. */
- for (i = 0; i < 0x60; ++i)
+ for (i = 0; i < 0x60; ++i)
init_one_io7_lsi(io7, i, boot_cpuid);

init_one_io7_lsi(io7, 0x74, boot_cpuid);
init_one_io7_lsi(io7, 0x75, boot_cpuid);

-
- /* Set up the msi irqs. */
- for (i = 128; i < (128 + 512); ++i) {
- irq_set_chip_and_handler(base + i, msi_ops, handle_level_irq);
- irq_set_status_flags(i, IRQ_LEVEL);
- }
-
for (i = 0; i < 16; ++i)
init_one_io7_msi(io7, i, boot_cpuid);

--
2.52.0