diff options
| author | Stratos Psomadakis <psomas@cslab.ece.ntua.gr> | 2012-01-12 15:44:47 +1030 |
|---|---|---|
| committer | Rusty Russell <rusty@rustcorp.com.au> | 2012-01-12 15:44:47 +1030 |
| commit | b6c96c0214138186f495e3ee73737c6fc5e4efa2 (patch) | |
| tree | 991ed5cd8c219543fb32f2b919556d5634859c90 | |
| parent | 07fe9977b6234ede1bd29e10e0323e478860c871 (diff) | |
| download | lwn-b6c96c0214138186f495e3ee73737c6fc5e4efa2.tar.gz lwn-b6c96c0214138186f495e3ee73737c6fc5e4efa2.zip | |
lguest: Make sure interrupt is allocated ok by lguest_setup_irq
Make sure the interrupt is allocated correctly by lguest_setup_irq (check the
return value of irq_alloc_desc_at for -ENOMEM)
Signed-off-by: Stratos Psomadakis <psomas@cslab.ece.ntua.gr>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (cleanups and commentry)
| -rw-r--r-- | arch/x86/lguest/boot.c | 21 | ||||
| -rw-r--r-- | drivers/lguest/lguest_device.c | 10 |
2 files changed, 20 insertions, 11 deletions
diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c index cf4603ba866f..642d8805bc1b 100644 --- a/arch/x86/lguest/boot.c +++ b/arch/x86/lguest/boot.c @@ -856,18 +856,23 @@ static void __init lguest_init_IRQ(void) } /* - * With CONFIG_SPARSE_IRQ, interrupt descriptors are allocated as-needed, so - * rather than set them in lguest_init_IRQ we are called here every time an - * lguest device needs an interrupt. - * - * FIXME: irq_alloc_desc_at() can fail due to lack of memory, we should - * pass that up! + * Interrupt descriptors are allocated as-needed, but low-numbered ones are + * reserved by the generic x86 code. So we ignore irq_alloc_desc_at if it + * tells us the irq is already used: other errors (ie. ENOMEM) we take + * seriously. */ -void lguest_setup_irq(unsigned int irq) +int lguest_setup_irq(unsigned int irq) { - irq_alloc_desc_at(irq, 0); + int err; + + /* Returns -ve error or vector number. */ + err = irq_alloc_desc_at(irq, 0); + if (err < 0 && err != -EEXIST) + return err; + irq_set_chip_and_handler_name(irq, &lguest_irq_controller, handle_level_irq, "level"); + return 0; } /* diff --git a/drivers/lguest/lguest_device.c b/drivers/lguest/lguest_device.c index 6a1d6447b864..9e8388efd88e 100644 --- a/drivers/lguest/lguest_device.c +++ b/drivers/lguest/lguest_device.c @@ -241,7 +241,7 @@ static void lg_notify(struct virtqueue *vq) } /* An extern declaration inside a C file is bad form. Don't do it. */ -extern void lguest_setup_irq(unsigned int irq); +extern int lguest_setup_irq(unsigned int irq); /* * This routine finds the Nth virtqueue described in the configuration of @@ -304,7 +304,9 @@ static struct virtqueue *lg_find_vq(struct virtio_device *vdev, } /* Make sure the interrupt is allocated. */ - lguest_setup_irq(lvq->config.irq); + err = lguest_setup_irq(lvq->config.irq); + if (err) + goto destroy_vring; /* * Tell the interrupt for this virtqueue to go to the virtio_ring @@ -317,7 +319,7 @@ static struct virtqueue *lg_find_vq(struct virtio_device *vdev, err = request_irq(lvq->config.irq, vring_interrupt, IRQF_SHARED, dev_name(&vdev->dev), vq); if (err) - goto destroy_vring; + goto free_desc; /* * Last of all we hook up our 'struct lguest_vq_info" to the @@ -326,6 +328,8 @@ static struct virtqueue *lg_find_vq(struct virtio_device *vdev, vq->priv = lvq; return vq; +free_desc: + irq_free_desc(lvq->config.irq); destroy_vring: vring_del_virtqueue(vq); unmap: |