| Message ID | 20170327094954.7162-9-lorenzo.pieralisi@arm.com |
|---|---|
| State | Changes Requested |
| Headers | show |
On Mon, Mar 27, 2017 at 10:49:36AM +0100, Lorenzo Pieralisi wrote: > The introduction of the ioremap_nopost() interface allows > kernel drivers to map memory through a dedicated kernel > interface providing non-posted writes semantics. > > Introduce two new functions in the Devres kernel layer and Devres > documentation: > > - devm_ioremap_nopost() > - devm_ioremap_nopost_resource() > > so that drivers can make use of devm_* interface to map memory > regions requiring non-posted writes memory attributes. > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > Cc: Jonathan Corbet <corbet@lwn.net> > Cc: Bjorn Helgaas <bhelgaas@google.com> > Cc: Tejun Heo <tj@kernel.org> > --- > Documentation/driver-model/devres.txt | 3 ++ > include/linux/device.h | 2 + > include/linux/io.h | 2 + > lib/devres.c | 78 +++++++++++++++++++++++++++++++++++ > 4 files changed, 85 insertions(+) > > diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt > index bf34d5b..9991a66 100644 > --- a/Documentation/driver-model/devres.txt > +++ b/Documentation/driver-model/devres.txt > @@ -294,7 +294,10 @@ IOMAP > devm_ioremap() > devm_ioremap_nocache() > devm_ioremap_wc() > + devm_ioremap_nopost() > devm_ioremap_resource() : checks resource, requests memory region, ioremaps > + devm_ioremap_nopost_resource() : do devm_ioremap_resource() with nopost > + memory attributes > devm_iounmap() > pcim_iomap() > pcim_iomap_regions() : do request_region() and iomap() on multiple BARs > diff --git a/include/linux/device.h b/include/linux/device.h > index 9ef518a..1dce865 100644 > --- a/include/linux/device.h > +++ b/include/linux/device.h > @@ -689,6 +689,8 @@ extern unsigned long devm_get_free_pages(struct device *dev, > extern void devm_free_pages(struct device *dev, unsigned long addr); > > void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res); > +void __iomem *devm_ioremap_nopost_resource(struct device *dev, > + struct resource *res); > > /* allows to add/remove a custom action to devres stack */ > int devm_add_action(struct device *dev, void (*action)(void *), void *data); > diff --git a/include/linux/io.h b/include/linux/io.h > index 82ef36e..e34d799 100644 > --- a/include/linux/io.h > +++ b/include/linux/io.h > @@ -79,6 +79,8 @@ void __iomem *devm_ioremap_nocache(struct device *dev, resource_size_t offset, > resource_size_t size); > void __iomem *devm_ioremap_wc(struct device *dev, resource_size_t offset, > resource_size_t size); > +void __iomem *devm_ioremap_nopost(struct device *dev, resource_size_t offset, > + resource_size_t size); > void devm_iounmap(struct device *dev, void __iomem *addr); > int check_signature(const volatile void __iomem *io_addr, > const unsigned char *signature, int length); > diff --git a/lib/devres.c b/lib/devres.c > index cb1464c..4e05660 100644 > --- a/lib/devres.c > +++ b/lib/devres.c > @@ -100,6 +100,34 @@ void __iomem *devm_ioremap_wc(struct device *dev, resource_size_t offset, > EXPORT_SYMBOL(devm_ioremap_wc); > > /** > + * devm_ioremap_nopost - Managed ioremap_nopost() > + * @dev: Generic device to remap IO address for > + * @offset: BUS offset to map I know this comment was just copied from other devm_ioremap*() interfaces, but I think it's slightly misleading to call this the "BUS offset". That suggests this is a bus address, but it is not. Maybe it should be "resource address" or similar? I propose a separate patch to update the existing comments, followed by this patch to add this new one. > + * @size: Size of map > + * > + * Managed ioremap_nopost(). Map is automatically unmapped on driver detach. > + */ > +void __iomem *devm_ioremap_nopost(struct device *dev, resource_size_t offset, > + resource_size_t size) > +{ > + void __iomem **ptr, *addr; > + > + ptr = devres_alloc(devm_ioremap_release, sizeof(*ptr), GFP_KERNEL); > + if (!ptr) > + return NULL; > + > + addr = ioremap_nopost(offset, size); > + if (addr) { > + *ptr = addr; > + devres_add(dev, ptr); > + } else > + devres_free(ptr); > + > + return addr; > +} > +EXPORT_SYMBOL(devm_ioremap_nopost); > + > +/** > * devm_iounmap - Managed iounmap() > * @dev: Generic device to unmap for > * @addr: Address to unmap > @@ -163,6 +191,56 @@ void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res) > } > EXPORT_SYMBOL(devm_ioremap_resource); > > +/** > + * devm_ioremap_nopost_resource() - devm_ioremap_resource() nopost version > + * @dev: generic device to handle the resource for > + * @res: resource to be handled > + * > + * Checks that a resource is a valid memory region, requests the memory > + * region and ioremaps it with ioremap_nopost() interface. > + * All operations are managed and will be undone on driver detach. > + * > + * Returns a pointer to the remapped memory or an ERR_PTR() encoded error code > + * on failure. Usage example: > + * > + * res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + * base = devm_ioremap_nopost_resource(&pdev->dev, res); > + * if (IS_ERR(base)) > + * return PTR_ERR(base); > + */ > +void __iomem *devm_ioremap_nopost_resource(struct device *dev, > + struct resource *res) > +{ > + resource_size_t size; > + const char *name; > + void __iomem *dest_ptr; > + > + BUG_ON(!dev); > + > + if (!res || resource_type(res) != IORESOURCE_MEM) { > + dev_err(dev, "invalid resource\n"); > + return IOMEM_ERR_PTR(-EINVAL); > + } > + > + size = resource_size(res); > + name = res->name ?: dev_name(dev); > + > + if (!devm_request_mem_region(dev, res->start, size, name)) { > + dev_err(dev, "can't request region for resource %pR\n", res); > + return IOMEM_ERR_PTR(-EBUSY); > + } > + > + dest_ptr = devm_ioremap_nopost(dev, res->start, size); > + if (!dest_ptr) { > + dev_err(dev, "ioremap failed for resource %pR\n", res); > + devm_release_mem_region(dev, res->start, size); > + dest_ptr = IOMEM_ERR_PTR(-ENOMEM); > + } > + > + return dest_ptr; > +} > +EXPORT_SYMBOL(devm_ioremap_nopost_resource); > + > #ifdef CONFIG_HAS_IOPORT_MAP > /* > * Generic iomap devres > -- > 2.10.0 >
On Mon, Mar 27, 2017 at 08:41:29PM -0500, Bjorn Helgaas wrote: > On Mon, Mar 27, 2017 at 10:49:36AM +0100, Lorenzo Pieralisi wrote: > > The introduction of the ioremap_nopost() interface allows > > kernel drivers to map memory through a dedicated kernel > > interface providing non-posted writes semantics. > > > > Introduce two new functions in the Devres kernel layer and Devres > > documentation: > > > > - devm_ioremap_nopost() > > - devm_ioremap_nopost_resource() > > > > so that drivers can make use of devm_* interface to map memory > > regions requiring non-posted writes memory attributes. > > > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > > Cc: Jonathan Corbet <corbet@lwn.net> > > Cc: Bjorn Helgaas <bhelgaas@google.com> > > Cc: Tejun Heo <tj@kernel.org> > > --- > > Documentation/driver-model/devres.txt | 3 ++ > > include/linux/device.h | 2 + > > include/linux/io.h | 2 + > > lib/devres.c | 78 +++++++++++++++++++++++++++++++++++ > > 4 files changed, 85 insertions(+) > > > > diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt > > index bf34d5b..9991a66 100644 > > --- a/Documentation/driver-model/devres.txt > > +++ b/Documentation/driver-model/devres.txt > > @@ -294,7 +294,10 @@ IOMAP > > devm_ioremap() > > devm_ioremap_nocache() > > devm_ioremap_wc() > > + devm_ioremap_nopost() > > devm_ioremap_resource() : checks resource, requests memory region, ioremaps > > + devm_ioremap_nopost_resource() : do devm_ioremap_resource() with nopost > > + memory attributes > > devm_iounmap() > > pcim_iomap() > > pcim_iomap_regions() : do request_region() and iomap() on multiple BARs > > diff --git a/include/linux/device.h b/include/linux/device.h > > index 9ef518a..1dce865 100644 > > --- a/include/linux/device.h > > +++ b/include/linux/device.h > > @@ -689,6 +689,8 @@ extern unsigned long devm_get_free_pages(struct device *dev, > > extern void devm_free_pages(struct device *dev, unsigned long addr); > > > > void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res); > > +void __iomem *devm_ioremap_nopost_resource(struct device *dev, > > + struct resource *res); > > > > /* allows to add/remove a custom action to devres stack */ > > int devm_add_action(struct device *dev, void (*action)(void *), void *data); > > diff --git a/include/linux/io.h b/include/linux/io.h > > index 82ef36e..e34d799 100644 > > --- a/include/linux/io.h > > +++ b/include/linux/io.h > > @@ -79,6 +79,8 @@ void __iomem *devm_ioremap_nocache(struct device *dev, resource_size_t offset, > > resource_size_t size); > > void __iomem *devm_ioremap_wc(struct device *dev, resource_size_t offset, > > resource_size_t size); > > +void __iomem *devm_ioremap_nopost(struct device *dev, resource_size_t offset, > > + resource_size_t size); > > void devm_iounmap(struct device *dev, void __iomem *addr); > > int check_signature(const volatile void __iomem *io_addr, > > const unsigned char *signature, int length); > > diff --git a/lib/devres.c b/lib/devres.c > > index cb1464c..4e05660 100644 > > --- a/lib/devres.c > > +++ b/lib/devres.c > > @@ -100,6 +100,34 @@ void __iomem *devm_ioremap_wc(struct device *dev, resource_size_t offset, > > EXPORT_SYMBOL(devm_ioremap_wc); > > > > /** > > + * devm_ioremap_nopost - Managed ioremap_nopost() > > + * @dev: Generic device to remap IO address for > > + * @offset: BUS offset to map > > I know this comment was just copied from other devm_ioremap*() > interfaces, but I think it's slightly misleading to call this the "BUS > offset". That suggests this is a bus address, but it is not. Maybe > it should be "resource address" or similar? > > I propose a separate patch to update the existing comments, followed > by this patch to add this new one. I agree with you, maybe Tejun has more context on why that parameter is called BUS offset ? Anyway, I can easily do what you suggest above, just asking Tejun if there is something I am missing. Tejun ? Thanks ! Lorenzo > > > + * @size: Size of map > > + * > > + * Managed ioremap_nopost(). Map is automatically unmapped on driver detach. > > + */ > > +void __iomem *devm_ioremap_nopost(struct device *dev, resource_size_t offset, > > + resource_size_t size) > > +{ > > + void __iomem **ptr, *addr; > > + > > + ptr = devres_alloc(devm_ioremap_release, sizeof(*ptr), GFP_KERNEL); > > + if (!ptr) > > + return NULL; > > + > > + addr = ioremap_nopost(offset, size); > > + if (addr) { > > + *ptr = addr; > > + devres_add(dev, ptr); > > + } else > > + devres_free(ptr); > > + > > + return addr; > > +} > > +EXPORT_SYMBOL(devm_ioremap_nopost); > > + > > +/** > > * devm_iounmap - Managed iounmap() > > * @dev: Generic device to unmap for > > * @addr: Address to unmap > > @@ -163,6 +191,56 @@ void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res) > > } > > EXPORT_SYMBOL(devm_ioremap_resource); > > > > +/** > > + * devm_ioremap_nopost_resource() - devm_ioremap_resource() nopost version > > + * @dev: generic device to handle the resource for > > + * @res: resource to be handled > > + * > > + * Checks that a resource is a valid memory region, requests the memory > > + * region and ioremaps it with ioremap_nopost() interface. > > + * All operations are managed and will be undone on driver detach. > > + * > > + * Returns a pointer to the remapped memory or an ERR_PTR() encoded error code > > + * on failure. Usage example: > > + * > > + * res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > > + * base = devm_ioremap_nopost_resource(&pdev->dev, res); > > + * if (IS_ERR(base)) > > + * return PTR_ERR(base); > > + */ > > +void __iomem *devm_ioremap_nopost_resource(struct device *dev, > > + struct resource *res) > > +{ > > + resource_size_t size; > > + const char *name; > > + void __iomem *dest_ptr; > > + > > + BUG_ON(!dev); > > + > > + if (!res || resource_type(res) != IORESOURCE_MEM) { > > + dev_err(dev, "invalid resource\n"); > > + return IOMEM_ERR_PTR(-EINVAL); > > + } > > + > > + size = resource_size(res); > > + name = res->name ?: dev_name(dev); > > + > > + if (!devm_request_mem_region(dev, res->start, size, name)) { > > + dev_err(dev, "can't request region for resource %pR\n", res); > > + return IOMEM_ERR_PTR(-EBUSY); > > + } > > + > > + dest_ptr = devm_ioremap_nopost(dev, res->start, size); > > + if (!dest_ptr) { > > + dev_err(dev, "ioremap failed for resource %pR\n", res); > > + devm_release_mem_region(dev, res->start, size); > > + dest_ptr = IOMEM_ERR_PTR(-ENOMEM); > > + } > > + > > + return dest_ptr; > > +} > > +EXPORT_SYMBOL(devm_ioremap_nopost_resource); > > + > > #ifdef CONFIG_HAS_IOPORT_MAP > > /* > > * Generic iomap devres > > -- > > 2.10.0 > >
Hello, On Tue, Mar 28, 2017 at 03:50:03PM +0100, Lorenzo Pieralisi wrote: > > I know this comment was just copied from other devm_ioremap*() > > interfaces, but I think it's slightly misleading to call this the "BUS > > offset". That suggests this is a bus address, but it is not. Maybe > > it should be "resource address" or similar? > > > > I propose a separate patch to update the existing comments, followed > > by this patch to add this new one. > > I agree with you, maybe Tejun has more context on why that parameter > is called BUS offset ? Anyway, I can easily do what you suggest above, > just asking Tejun if there is something I am missing. I'm pretty sure I copied it from somewhere without thinking much about it. Please feel free to change. Thanks.
diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt index bf34d5b..9991a66 100644 --- a/Documentation/driver-model/devres.txt +++ b/Documentation/driver-model/devres.txt @@ -294,7 +294,10 @@ IOMAP devm_ioremap() devm_ioremap_nocache() devm_ioremap_wc() + devm_ioremap_nopost() devm_ioremap_resource() : checks resource, requests memory region, ioremaps + devm_ioremap_nopost_resource() : do devm_ioremap_resource() with nopost + memory attributes devm_iounmap() pcim_iomap() pcim_iomap_regions() : do request_region() and iomap() on multiple BARs diff --git a/include/linux/device.h b/include/linux/device.h index 9ef518a..1dce865 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -689,6 +689,8 @@ extern unsigned long devm_get_free_pages(struct device *dev, extern void devm_free_pages(struct device *dev, unsigned long addr); void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res); +void __iomem *devm_ioremap_nopost_resource(struct device *dev, + struct resource *res); /* allows to add/remove a custom action to devres stack */ int devm_add_action(struct device *dev, void (*action)(void *), void *data); diff --git a/include/linux/io.h b/include/linux/io.h index 82ef36e..e34d799 100644 --- a/include/linux/io.h +++ b/include/linux/io.h @@ -79,6 +79,8 @@ void __iomem *devm_ioremap_nocache(struct device *dev, resource_size_t offset, resource_size_t size); void __iomem *devm_ioremap_wc(struct device *dev, resource_size_t offset, resource_size_t size); +void __iomem *devm_ioremap_nopost(struct device *dev, resource_size_t offset, + resource_size_t size); void devm_iounmap(struct device *dev, void __iomem *addr); int check_signature(const volatile void __iomem *io_addr, const unsigned char *signature, int length); diff --git a/lib/devres.c b/lib/devres.c index cb1464c..4e05660 100644 --- a/lib/devres.c +++ b/lib/devres.c @@ -100,6 +100,34 @@ void __iomem *devm_ioremap_wc(struct device *dev, resource_size_t offset, EXPORT_SYMBOL(devm_ioremap_wc); /** + * devm_ioremap_nopost - Managed ioremap_nopost() + * @dev: Generic device to remap IO address for + * @offset: BUS offset to map + * @size: Size of map + * + * Managed ioremap_nopost(). Map is automatically unmapped on driver detach. + */ +void __iomem *devm_ioremap_nopost(struct device *dev, resource_size_t offset, + resource_size_t size) +{ + void __iomem **ptr, *addr; + + ptr = devres_alloc(devm_ioremap_release, sizeof(*ptr), GFP_KERNEL); + if (!ptr) + return NULL; + + addr = ioremap_nopost(offset, size); + if (addr) { + *ptr = addr; + devres_add(dev, ptr); + } else + devres_free(ptr); + + return addr; +} +EXPORT_SYMBOL(devm_ioremap_nopost); + +/** * devm_iounmap - Managed iounmap() * @dev: Generic device to unmap for * @addr: Address to unmap @@ -163,6 +191,56 @@ void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res) } EXPORT_SYMBOL(devm_ioremap_resource); +/** + * devm_ioremap_nopost_resource() - devm_ioremap_resource() nopost version + * @dev: generic device to handle the resource for + * @res: resource to be handled + * + * Checks that a resource is a valid memory region, requests the memory + * region and ioremaps it with ioremap_nopost() interface. + * All operations are managed and will be undone on driver detach. + * + * Returns a pointer to the remapped memory or an ERR_PTR() encoded error code + * on failure. Usage example: + * + * res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + * base = devm_ioremap_nopost_resource(&pdev->dev, res); + * if (IS_ERR(base)) + * return PTR_ERR(base); + */ +void __iomem *devm_ioremap_nopost_resource(struct device *dev, + struct resource *res) +{ + resource_size_t size; + const char *name; + void __iomem *dest_ptr; + + BUG_ON(!dev); + + if (!res || resource_type(res) != IORESOURCE_MEM) { + dev_err(dev, "invalid resource\n"); + return IOMEM_ERR_PTR(-EINVAL); + } + + size = resource_size(res); + name = res->name ?: dev_name(dev); + + if (!devm_request_mem_region(dev, res->start, size, name)) { + dev_err(dev, "can't request region for resource %pR\n", res); + return IOMEM_ERR_PTR(-EBUSY); + } + + dest_ptr = devm_ioremap_nopost(dev, res->start, size); + if (!dest_ptr) { + dev_err(dev, "ioremap failed for resource %pR\n", res); + devm_release_mem_region(dev, res->start, size); + dest_ptr = IOMEM_ERR_PTR(-ENOMEM); + } + + return dest_ptr; +} +EXPORT_SYMBOL(devm_ioremap_nopost_resource); + #ifdef CONFIG_HAS_IOPORT_MAP /* * Generic iomap devres
The introduction of the ioremap_nopost() interface allows kernel drivers to map memory through a dedicated kernel interface providing non-posted writes semantics. Introduce two new functions in the Devres kernel layer and Devres documentation: - devm_ioremap_nopost() - devm_ioremap_nopost_resource() so that drivers can make use of devm_* interface to map memory regions requiring non-posted writes memory attributes. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Tejun Heo <tj@kernel.org> --- Documentation/driver-model/devres.txt | 3 ++ include/linux/device.h | 2 + include/linux/io.h | 2 + lib/devres.c | 78 +++++++++++++++++++++++++++++++++++ 4 files changed, 85 insertions(+)