Commit 6db6a5f3 authored by Rusty Russell's avatar Rusty Russell
Browse files

lguest: fix for CONFIG_SPARSE_IRQ=y 



Impact: remove lots of lguest boot WARN_ON() when CONFIG_SPARSE_IRQ=y

We now need to call irq_to_desc_alloc_cpu() before
set_irq_chip_and_handler_name(), but we can't do that from init_IRQ (no
kmalloc available).

So do it as we use interrupts instead.  Also means we only alloc for
irqs we use, which was the intent of CONFIG_SPARSE_IRQ anyway.

Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@redhat.com>
parent cbd88c8e

arch/x86/lguest/boot.c

+9 −7
Original line number Diff line number Diff line
@@ -594,19 +594,21 @@ static void __init lguest_init_IRQ(void) 
		/* Some systems map "vectors" to interrupts weirdly.  Lguest has

		 * a straightforward 1 to 1 mapping, so force that here. */

		__get_cpu_var(vector_irq)[vector] = i;

		if (vector != SYSCALL_VECTOR) {

			set_intr_gate(vector,

				      interrupt[vector-FIRST_EXTERNAL_VECTOR]);

			set_irq_chip_and_handler_name(i, &lguest_irq_controller,

						      handle_level_irq,

						      "level");

		}

		if (vector != SYSCALL_VECTOR)

			set_intr_gate(vector, interrupt[i]);

	}

	/* This call is required to set up for 4k stacks, where we have

	 * separate stacks for hard and soft interrupts. */

	irq_ctx_init(smp_processor_id());

}



void lguest_setup_irq(unsigned int irq)

{

	irq_to_desc_alloc_cpu(irq, 0);

	set_irq_chip_and_handler_name(irq, &lguest_irq_controller,

				      handle_level_irq, "level");

}



/*

 * Time.

 *

drivers/lguest/lguest_device.c

+6 −0
Original line number Diff line number Diff line
@@ -212,6 +212,9 @@ static void lg_notify(struct virtqueue *vq) 
	hcall(LHCALL_NOTIFY, lvq->config.pfn << PAGE_SHIFT, 0, 0);

}



/* An extern declaration inside a C file is bad form.  Don't do it. */

extern void lguest_setup_irq(unsigned int irq);



/* This routine finds the first virtqueue described in the configuration of

 * this device and sets it up.

 *
@@ -266,6 +269,9 @@ static struct virtqueue *lg_find_vq(struct virtio_device *vdev, 
		goto unmap;

	}



	/* Make sure the interrupt is allocated. */

	lguest_setup_irq(lvq->config.irq);



	/* Tell the interrupt for this virtqueue to go to the virtio_ring

	 * interrupt handler. */

	/* FIXME: We used to have a flag for the Host to tell us we could use

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