On Wednesday, August 11, 2021, David Hildenbrand <[email protected]> wrote:
> Let's clean it up a bit, removing the unnecessary usage of r_next() by > next_resource(), and use next_range_resource() in case we are not > interested in a certain subtree. > > Signed-off-by: David Hildenbrand <[email protected]> > --- > kernel/resource.c | 19 +++++++++++-------- > 1 file changed, 11 insertions(+), 8 deletions(-) > > diff --git a/kernel/resource.c b/kernel/resource.c > index 2938cf520ca3..ea853a075a83 100644 > --- a/kernel/resource.c > +++ b/kernel/resource.c > @@ -1754,9 +1754,8 @@ static int strict_iomem_checks; > */ > bool iomem_is_exclusive(u64 addr) > { > - struct resource *p = &iomem_resource; > + struct resource *p; > bool err = false; > - loff_t l; > int size = PAGE_SIZE; > > if (!strict_iomem_checks) > @@ -1765,27 +1764,31 @@ bool iomem_is_exclusive(u64 addr) > addr = addr & PAGE_MASK; > > read_lock(&resource_lock); > - for (p = p->child; p ; p = r_next(NULL, p, &l)) { > + for (p = iomem_resource.child; p ;) { I consider the ordinal part of p initialization is slightly better and done outside of read lock. Something like p= &iomem_res...; read lock for (p = p->child; ...) { > /* > * We can probably skip the resources without > * IORESOURCE_IO attribute? > */ > if (p->start >= addr + size) > break; > - if (p->end < addr) > + if (p->end < addr) { > + /* No need to consider children */ > + p = next_resource_skip_children(p); > continue; > + } > + > /* > * A resource is exclusive if IORESOURCE_EXCLUSIVE is set > * or CONFIG_IO_STRICT_DEVMEM is enabled and the > * resource is busy. > */ > - if ((p->flags & IORESOURCE_BUSY) == 0) > - continue; > - if (IS_ENABLED(CONFIG_IO_STRICT_DEVMEM) > - || p->flags & IORESOURCE_EXCLUSIVE) { > + if (p->flags & IORESOURCE_BUSY && > + (IS_ENABLED(CONFIG_IO_STRICT_DEVMEM) || > + p->flags & IORESOURCE_EXCLUSIVE)) { > err = true; > break; > } > + p = next_resource(p); > } > read_unlock(&resource_lock); > > -- > 2.31.1 > > -- With Best Regards, Andy Shevchenko
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