On Fri, 27 Mar 2020 08:07:20 +0000 "Tian, Kevin" <[email protected]> wrote:
> > From: Jacob Pan <[email protected]> > > Sent: Thursday, March 26, 2020 1:55 AM > > > > IOASID is a limited system-wide resource that can be allocated at > > runtime. This limitation can be enumerated during boot. For > > example, on x86 platforms, PCI Process Address Space ID (PASID) > > allocation uses IOASID service. The number of supported PASID bits > > are enumerated by extended capability register as defined in the > > VT-d spec. > > > > This patch adds a helper to set the system capacity, it expected to > > be set during boot prior to any allocation request. > > > > Signed-off-by: Jacob Pan <[email protected]> > > --- > > drivers/iommu/ioasid.c | 15 +++++++++++++++ > > include/linux/ioasid.h | 5 ++++- > > 2 files changed, 19 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/iommu/ioasid.c b/drivers/iommu/ioasid.c > > index 0f8dd377aada..4026e52855b9 100644 > > --- a/drivers/iommu/ioasid.c > > +++ b/drivers/iommu/ioasid.c > > @@ -17,6 +17,21 @@ struct ioasid_data { > > struct rcu_head rcu; > > }; > > > > +static ioasid_t ioasid_capacity; > > +static ioasid_t ioasid_capacity_avail; > > + > > +/* System capacity can only be set once */ > > +void ioasid_install_capacity(ioasid_t total) > > +{ > > + if (ioasid_capacity) { > > + pr_warn("IOASID capacity already set at %d\n", > > ioasid_capacity); > > + return; > > + } > > + > > + ioasid_capacity = ioasid_capacity_avail = total; > > +} > > +EXPORT_SYMBOL_GPL(ioasid_install_capacity); > > + > > From all the texts in this patch, looks ioasid_set_capacity might be > a better name? > That was my initial choice as well :), but it may get confused with ioasid_set. I will rephrase the text to avoid 'set'. > > /* > > * struct ioasid_allocator_data - Internal data structure to hold > > information > > * about an allocator. There are two types of allocators: > > diff --git a/include/linux/ioasid.h b/include/linux/ioasid.h > > index 6f000d7a0ddc..9711fa0dc357 100644 > > --- a/include/linux/ioasid.h > > +++ b/include/linux/ioasid.h > > @@ -40,7 +40,7 @@ void *ioasid_find(struct ioasid_set *set, > > ioasid_t ioasid, int ioasid_register_allocator(struct > > ioasid_allocator_ops *allocator); void > > ioasid_unregister_allocator(struct ioasid_allocator_ops > > *allocator); int ioasid_set_data(ioasid_t ioasid, void *data); - > > +void ioasid_install_capacity(ioasid_t total); > > #else /* !CONFIG_IOASID */ > > static inline ioasid_t ioasid_alloc(struct ioasid_set *set, > > ioasid_t min, ioasid_t max, void *private) > > @@ -72,5 +72,8 @@ static inline int ioasid_set_data(ioasid_t > > ioasid, void *data) > > return -ENOTSUPP; > > } > > > > +static inline void ioasid_install_capacity(ioasid_t total) > > +{ > > +} > > #endif /* CONFIG_IOASID */ > > #endif /* __LINUX_IOASID_H */ > > -- > > 2.7.4 > [Jacob Pan] _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
