Commit a438322e authored Oct 24, 2023 by Herve Codina Committed by Greg Kroah-Hartman Nov 28, 2023

genirq/generic_chip: Make irq_remove_generic_chip() irqdomain aware

commit 5e7afb2eb7b2a7c81e9f608cbdf74a07606fd1b5 upstream.

irq_remove_generic_chip() calculates the Linux interrupt number for removing the
handler and interrupt chip based on gc::irq_base as a linear function of
the bit positions of set bits in the @msk argument.

When the generic chip is present in an irq domain, i.e. created with a call
to irq_alloc_domain_generic_chips(), gc::irq_base contains not the base
Linux interrupt number. It contains the base hardware interrupt for this
chip. It is set to 0 for the first chip in the domain, 0 + N for the next
chip, where $N is the number of hardware interrupts per chip.

That means the Linux interrupt number cannot be calculated based on
gc::irq_base for irqdomain based chips without a domain map lookup, which
is currently missing.

Rework the code to take the irqdomain case into account and calculate the
Linux interrupt number by a irqdomain lookup of the domain specific
hardware interrupt number.

[ tglx: Massage changelog. Reshuffle the logic and add a proper comment. ]

Fixes: cfefd21e ("genirq: Add chip suspend and resume callbacks")
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20231024150335.322282-1-herve.codina@bootlin.com

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 683c562c

kernel/irq/generic-chip.c

+19 −6

Original line number	Diff line number	Diff line
		@@ -537,21 +537,34 @@ EXPORT_SYMBOL_GPL(irq_setup_alt_chip);
		void irq_remove_generic_chip(struct irq_chip_generic *gc, u32 msk,
		unsigned int clr, unsigned int set)
		{
		unsigned int i = gc->irq_base;
		unsigned int i, virq;

		raw_spin_lock(&gc_lock);
		list_del(&gc->list);
		raw_spin_unlock(&gc_lock);

		for (; msk; msk >>= 1, i++) {
		for (i = 0; msk; msk >>= 1, i++) {
		if (!(msk & 0x01))
		continue;

		/*
		* Interrupt domain based chips store the base hardware
		* interrupt number in gc::irq_base. Otherwise gc::irq_base
		* contains the base Linux interrupt number.
		*/
		if (gc->domain) {
		virq = irq_find_mapping(gc->domain, gc->irq_base + i);
		if (!virq)
		continue;
		} else {
		virq = gc->irq_base + i;
		}

		/* Remove handler first. That will mask the irq line */
		irq_set_handler(i, NULL);
		irq_set_chip(i, &no_irq_chip);
		irq_set_chip_data(i, NULL);
		irq_modify_status(i, clr, set);
		irq_set_handler(virq, NULL);
		irq_set_chip(virq, &no_irq_chip);
		irq_set_chip_data(virq, NULL);
		irq_modify_status(virq, clr, set);
		}
		}
		EXPORT_SYMBOL_GPL(irq_remove_generic_chip);