Messages in this thread | | | From | "Tian, Kevin" <> | Subject | RE: [PATCH 01/10] iommu/ioasid: Introduce system-wide capacity | Date | Fri, 27 Mar 2020 08:07:20 +0000 |
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> From: Jacob Pan <jacob.jun.pan@linux.intel.com> > 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 <jacob.jun.pan@linux.intel.com> > --- > 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?
> /* > * 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
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