| Message ID | 20221111132706.388892782@linutronix.de |
|---|---|
| State | New |
| Headers | show |
| Series | genirq, PCI/MSI: Support for per device MSI and PCI/IMS - Part 2 API rework | expand |
> From: Thomas Gleixner <tglx@linutronix.de> > Sent: Friday, November 11, 2022 9:57 PM > > @@ -937,13 +937,21 @@ int msi_domain_alloc_irqs_descs_locked(s > > lockdep_assert_held(&dev->msi.data->mutex); > > + if (WARN_ON_ONCE(irq_domain_is_msi_parent(domain))) { > + ret = -EINVAL; > + goto free; > + } > + > + /* Frees allocated descriptors in case of failure. */ > ret = msi_domain_add_simple_msi_descs(info, dev, nvec); > if (ret) > return ret; it's unusual to see a direct return when error unwind is already required at an early failure point. is it something which can be improved here?
On Fri, Nov 18 2022 at 07:50, Kevin Tian wrote: >> From: Thomas Gleixner <tglx@linutronix.de> >> Sent: Friday, November 11, 2022 9:57 PM >> >> @@ -937,13 +937,21 @@ int msi_domain_alloc_irqs_descs_locked(s >> >> lockdep_assert_held(&dev->msi.data->mutex); >> >> + if (WARN_ON_ONCE(irq_domain_is_msi_parent(domain))) { >> + ret = -EINVAL; >> + goto free; >> + } >> + >> + /* Frees allocated descriptors in case of failure. */ >> ret = msi_domain_add_simple_msi_descs(info, dev, nvec); >> if (ret) >> return ret; > > it's unusual to see a direct return when error unwind is already required > at an early failure point. is it something which can be improved here? It's redundant in this case, but you are right it looks weird.
--- a/kernel/irq/msi.c +++ b/kernel/irq/msi.c @@ -937,13 +937,21 @@ int msi_domain_alloc_irqs_descs_locked(s lockdep_assert_held(&dev->msi.data->mutex); + if (WARN_ON_ONCE(irq_domain_is_msi_parent(domain))) { + ret = -EINVAL; + goto free; + } + + /* Frees allocated descriptors in case of failure. */ ret = msi_domain_add_simple_msi_descs(info, dev, nvec); if (ret) return ret; ret = ops->domain_alloc_irqs(domain, dev, nvec); - if (ret) - msi_domain_free_irqs_descs_locked(domain, dev); + if (!ret) + return 0; +free: + msi_domain_free_irqs_descs_locked(domain, dev); return ret; } @@ -1013,6 +1021,9 @@ void msi_domain_free_irqs_descs_locked(s lockdep_assert_held(&dev->msi.data->mutex); + if (WARN_ON_ONCE(irq_domain_is_msi_parent(domain))) + return; + ops->domain_free_irqs(domain, dev); if (ops->msi_post_free) ops->msi_post_free(domain, dev);
In the upcoming per device MSI domain concept the MSI parent domains are not allowed to be used as regular MSI domains where the MSI allocation/free operations are applicable. Add appropriate checks. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> --- kernel/irq/msi.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-)