| Message ID | 20210419070109.4780-2-apopple@nvidia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v5,1/3] kernel/resource: Allow region_intersects users to hold resource_lock | expand |
On 19.04.21 09:01, Alistair Popple wrote: > Refactor the portion of __request_region() done whilst holding the > resource_lock into a separate function to allow callers to hold the > lock. > > Signed-off-by: Alistair Popple <apopple@nvidia.com> > --- > kernel/resource.c | 52 +++++++++++++++++++++++++++++------------------ > 1 file changed, 32 insertions(+), 20 deletions(-) > > diff --git a/kernel/resource.c b/kernel/resource.c > index 736768587d2d..75f8da722497 100644 > --- a/kernel/resource.c > +++ b/kernel/resource.c > @@ -1181,31 +1181,16 @@ struct address_space *iomem_get_mapping(void) > return smp_load_acquire(&iomem_inode)->i_mapping; > } > > -/** > - * __request_region - create a new busy resource region > - * @parent: parent resource descriptor > - * @start: resource start address > - * @n: resource region size > - * @name: reserving caller's ID string > - * @flags: IO resource flags > - */ > -struct resource * __request_region(struct resource *parent, > +static int __request_region_locked(struct resource *res, struct resource *parent, > resource_size_t start, resource_size_t n, > const char *name, int flags) > { > DECLARE_WAITQUEUE(wait, current); > - struct resource *res = alloc_resource(GFP_KERNEL); > - struct resource *orig_parent = parent; > - > - if (!res) > - return NULL; > > res->name = name; > res->start = start; > res->end = start + n - 1; > > - write_lock(&resource_lock); > - > for (;;) { > struct resource *conflict; > > @@ -1241,13 +1226,40 @@ struct resource * __request_region(struct resource *parent, > continue; > } > /* Uhhuh, that didn't work out.. */ > - free_resource(res); > - res = NULL; > - break; > + return -EBUSY; > } > + > + return 0; > +} > + > +/** > + * __request_region - create a new busy resource region > + * @parent: parent resource descriptor > + * @start: resource start address > + * @n: resource region size > + * @name: reserving caller's ID string > + * @flags: IO resource flags > + */ > +struct resource *__request_region(struct resource *parent, > + resource_size_t start, resource_size_t n, > + const char *name, int flags) > +{ > + struct resource *res = alloc_resource(GFP_KERNEL); > + int ret; > + > + if (!res) > + return NULL; > + > + write_lock(&resource_lock); > + ret = __request_region_locked(res, parent, start, n, name, flags); > write_unlock(&resource_lock); > > - if (res && orig_parent == &iomem_resource) > + if (ret) { > + free_resource(res); > + return NULL; > + } > + > + if (parent == &iomem_resource) > revoke_iomem(res); Reviewed-by: David Hildenbrand <david@redhat.com>
diff --git a/kernel/resource.c b/kernel/resource.c index 736768587d2d..75f8da722497 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -1181,31 +1181,16 @@ struct address_space *iomem_get_mapping(void) return smp_load_acquire(&iomem_inode)->i_mapping; } -/** - * __request_region - create a new busy resource region - * @parent: parent resource descriptor - * @start: resource start address - * @n: resource region size - * @name: reserving caller's ID string - * @flags: IO resource flags - */ -struct resource * __request_region(struct resource *parent, +static int __request_region_locked(struct resource *res, struct resource *parent, resource_size_t start, resource_size_t n, const char *name, int flags) { DECLARE_WAITQUEUE(wait, current); - struct resource *res = alloc_resource(GFP_KERNEL); - struct resource *orig_parent = parent; - - if (!res) - return NULL; res->name = name; res->start = start; res->end = start + n - 1; - write_lock(&resource_lock); - for (;;) { struct resource *conflict; @@ -1241,13 +1226,40 @@ struct resource * __request_region(struct resource *parent, continue; } /* Uhhuh, that didn't work out.. */ - free_resource(res); - res = NULL; - break; + return -EBUSY; } + + return 0; +} + +/** + * __request_region - create a new busy resource region + * @parent: parent resource descriptor + * @start: resource start address + * @n: resource region size + * @name: reserving caller's ID string + * @flags: IO resource flags + */ +struct resource *__request_region(struct resource *parent, + resource_size_t start, resource_size_t n, + const char *name, int flags) +{ + struct resource *res = alloc_resource(GFP_KERNEL); + int ret; + + if (!res) + return NULL; + + write_lock(&resource_lock); + ret = __request_region_locked(res, parent, start, n, name, flags); write_unlock(&resource_lock); - if (res && orig_parent == &iomem_resource) + if (ret) { + free_resource(res); + return NULL; + } + + if (parent == &iomem_resource) revoke_iomem(res); return res;
Refactor the portion of __request_region() done whilst holding the resource_lock into a separate function to allow callers to hold the lock. Signed-off-by: Alistair Popple <apopple@nvidia.com> --- kernel/resource.c | 52 +++++++++++++++++++++++++++++------------------ 1 file changed, 32 insertions(+), 20 deletions(-)