On Fri, Apr 02, 2021 at 06:05:36PM +0900, Hector Martin wrote: > This implements the 'nonposted-mmio' boolean property. Placing this > property in a bus marks all direct child devices as requiring > non-posted MMIO mappings. If no such property is found, the default > is posted MMIO. > > of_mmio_is_nonposted() performs this check to determine if a given > device has requested non-posted MMIO. > > of_address_to_resource() uses this to set the IORESOURCE_MEM_NONPOSTED > flag on resources that require non-posted MMIO. > > of_iomap() and of_io_request_and_map() then use this flag to pick the > correct ioremap() variant. > > This mechanism is currently restricted to builds that support Apple ARM > platforms, as an optimization. > > Reviewed-by: Linus Walleij <[email protected]> > Signed-off-by: Hector Martin <[email protected]> > --- > drivers/of/address.c | 43 ++++++++++++++++++++++++++++++++++++-- > include/linux/of_address.h | 1 + > 2 files changed, 42 insertions(+), 2 deletions(-) > > diff --git a/drivers/of/address.c b/drivers/of/address.c > index 73ddf2540f3f..6485cc536e81 100644 > --- a/drivers/of/address.c > +++ b/drivers/of/address.c > @@ -847,6 +847,9 @@ static int __of_address_to_resource(struct device_node > *dev, > return -EINVAL; > memset(r, 0, sizeof(struct resource)); > > + if (of_mmio_is_nonposted(dev)) > + flags |= IORESOURCE_MEM_NONPOSTED; > + > r->start = taddr; > r->end = taddr + size - 1; > r->flags = flags; > @@ -896,7 +899,10 @@ void __iomem *of_iomap(struct device_node *np, int index) > if (of_address_to_resource(np, index, &res)) > return NULL; > > - return ioremap(res.start, resource_size(&res)); > + if (res.flags & IORESOURCE_MEM_NONPOSTED) > + return ioremap_np(res.start, resource_size(&res)); > + else > + return ioremap(res.start, resource_size(&res)); > } > EXPORT_SYMBOL(of_iomap); > > @@ -928,7 +934,11 @@ void __iomem *of_io_request_and_map(struct device_node > *np, int index, > if (!request_mem_region(res.start, resource_size(&res), name)) > return IOMEM_ERR_PTR(-EBUSY); > > - mem = ioremap(res.start, resource_size(&res)); > + if (res.flags & IORESOURCE_MEM_NONPOSTED) > + mem = ioremap_np(res.start, resource_size(&res)); > + else > + mem = ioremap(res.start, resource_size(&res)); > + > if (!mem) { > release_mem_region(res.start, resource_size(&res)); > return IOMEM_ERR_PTR(-ENOMEM); > @@ -1094,3 +1104,32 @@ bool of_dma_is_coherent(struct device_node *np) > return false; > } > EXPORT_SYMBOL_GPL(of_dma_is_coherent); > + > +/** > + * of_mmio_is_nonposted - Check if device uses non-posted MMIO > + * @np: device node > + * > + * Returns true if the "nonposted-mmio" property was found for > + * the device's bus. > + * > + * This is currently only enabled on builds that support Apple ARM devices, > as > + * an optimization. > + */ > +bool of_mmio_is_nonposted(struct device_node *np) > +{ > + struct device_node *parent; > + bool nonposted; > + > + if (!IS_ENABLED(CONFIG_ARCH_APPLE)) > + return false; > + > + parent = of_get_parent(np); > + if (!parent) > + return false; > + > + nonposted = of_property_read_bool(parent, "nonposted-mmio"); > + > + of_node_put(parent); > + return nonposted; > +} > +EXPORT_SYMBOL_GPL(of_mmio_is_nonposted);
Is this needed outside of of/address.c? If not, please make it static and don't export. With that, Reviewed-by: Rob Herring <[email protected]>
