[RESEND] [PATCH v8 8/9] pci: Add support for creating a generic host_bridge from device tree
Liviu Dudau
liviu at dudau.co.uk
Tue Jul 1 14:04:10 PDT 2014
It is clearly not my day today! This will fail compilation on ARCH=arm due to
missing header include for <linux/slab.h>
Will send an update tomorrow after more testing. Sorry!
Liviu
On Tue, Jul 01, 2014 at 09:50:50PM +0100, Liviu Dudau wrote:
> Several platforms use a rather generic version of parsing
> the device tree to find the host bridge ranges. Move the common code
> into the generic PCI code and use it to create a pci_host_bridge
> structure that can be used by arch code.
>
> Based on early attempts by Andrew Murray to unify the code.
> Used powerpc and microblaze PCI code as starting point.
>
> Signed-off-by: Liviu Dudau <Liviu.Dudau at arm.com>
> Tested-by: Tanmay Inamdar <tinamdar at apm.com>
> ---
> drivers/of/of_pci.c | 136 ++++++++++++++++++++++++++++++++++++++++++++++
> drivers/pci/host-bridge.c | 15 +++++
> include/linux/of_pci.h | 10 ++++
> include/linux/pci.h | 8 +++
> 4 files changed, 169 insertions(+)
>
> diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c
> index 8481996..e81402a 100644
> --- a/drivers/of/of_pci.c
> +++ b/drivers/of/of_pci.c
> @@ -1,6 +1,7 @@
> #include <linux/kernel.h>
> #include <linux/export.h>
> #include <linux/of.h>
> +#include <linux/of_address.h>
> #include <linux/of_pci.h>
>
> static inline int __of_pci_pci_compare(struct device_node *node,
> @@ -89,6 +90,141 @@ int of_pci_parse_bus_range(struct device_node *node, struct resource *res)
> }
> EXPORT_SYMBOL_GPL(of_pci_parse_bus_range);
>
> +/**
> + * pci_host_bridge_of_get_ranges - Parse PCI host bridge resources from DT
> + * @dev: device node of the host bridge having the range property
> + * @resources: list where the range of resources will be added after DT parsing
> + * @io_base: pointer to a variable that will contain the physical address for
> + * the start of the I/O range.
> + *
> + * It is the callers job to free the @resources list if an error is returned.
> + *
> + * This function will parse the "ranges" property of a PCI host bridge device
> + * node and setup the resource mapping based on its content. It is expected
> + * that the property conforms with the Power ePAPR document.
> + *
> + * Each architecture is then offered the chance of applying their own
> + * filtering of pci_host_bridge_windows based on their own restrictions by
> + * calling pcibios_fixup_bridge_ranges(). The filtered list of windows
> + * can then be used when creating a pci_host_bridge structure.
> + */
> +static int pci_host_bridge_of_get_ranges(struct device_node *dev,
> + struct list_head *resources, resource_size_t *io_base)
> +{
> + struct resource *res;
> + struct of_pci_range range;
> + struct of_pci_range_parser parser;
> + int err;
> +
> + pr_info("PCI host bridge %s ranges:\n", dev->full_name);
> +
> + /* Check for ranges property */
> + err = of_pci_range_parser_init(&parser, dev);
> + if (err)
> + return err;
> +
> + pr_debug("Parsing ranges property...\n");
> + for_each_of_pci_range(&parser, &range) {
> + /* Read next ranges element */
> + pr_debug("pci_space: 0x%08x pci_addr:0x%016llx cpu_addr:0x%016llx size:0x%016llx\n",
> + range.pci_space, range.pci_addr, range.cpu_addr, range.size);
> +
> + /*
> + * If we failed translation or got a zero-sized region
> + * then skip this range
> + */
> + if (range.cpu_addr == OF_BAD_ADDR || range.size == 0)
> + continue;
> +
> + res = kzalloc(sizeof(struct resource), GFP_KERNEL);
> + if (!res)
> + return -ENOMEM;
> +
> + err = of_pci_range_to_resource(&range, dev, res);
> + if (err)
> + return err;
> +
> + if (resource_type(res) == IORESOURCE_IO)
> + *io_base = range.cpu_addr;
> +
> + pci_add_resource_offset(resources, res,
> + res->start - range.pci_addr);
> + }
> +
> + /* Apply architecture specific fixups for the ranges */
> + return pcibios_fixup_bridge_ranges(resources);
> +}
> +
> +static atomic_t domain_nr = ATOMIC_INIT(-1);
> +
> +/**
> + * of_create_pci_host_bridge - Create a PCI host bridge structure using
> + * information passed in the DT.
> + * @parent: device owning this host bridge
> + * @ops: pci_ops associated with the host controller
> + * @host_data: opaque data structure used by the host controller.
> + *
> + * returns a pointer to the newly created pci_host_bridge structure, or
> + * NULL if the call failed.
> + *
> + * This function will try to obtain the host bridge domain number by
> + * using of_alias_get_id() call with "pci-domain" as a stem. If that
> + * fails, a local allocator will be used that will put each host bridge
> + * in a new domain.
> + */
> +struct pci_host_bridge *
> +of_create_pci_host_bridge(struct device *parent, struct pci_ops *ops, void *host_data)
> +{
> + int err, domain, busno;
> + struct resource *bus_range;
> + struct pci_bus *root_bus;
> + struct pci_host_bridge *bridge;
> + resource_size_t io_base = 0;
> + LIST_HEAD(res);
> +
> + bus_range = kzalloc(sizeof(*bus_range), GFP_KERNEL);
> + if (!bus_range)
> + return ERR_PTR(-ENOMEM);
> +
> + domain = of_alias_get_id(parent->of_node, "pci-domain");
> + if (domain == -ENODEV)
> + domain = atomic_inc_return(&domain_nr);
> +
> + err = of_pci_parse_bus_range(parent->of_node, bus_range);
> + if (err) {
> + dev_info(parent, "No bus range for %s, using default [0-255]\n",
> + parent->of_node->full_name);
> + bus_range->start = 0;
> + bus_range->end = 255;
> + bus_range->flags = IORESOURCE_BUS;
> + }
> + busno = bus_range->start;
> + pci_add_resource(&res, bus_range);
> +
> + /* now parse the rest of host bridge bus ranges */
> + err = pci_host_bridge_of_get_ranges(parent->of_node, &res, &io_base);
> + if (err)
> + goto err_create;
> +
> + /* then create the root bus */
> + root_bus = pci_create_root_bus_in_domain(parent, domain, busno,
> + ops, host_data, &res);
> + if (IS_ERR(root_bus)) {
> + err = PTR_ERR(root_bus);
> + goto err_create;
> + }
> +
> + bridge = to_pci_host_bridge(root_bus->bridge);
> + bridge->io_base = io_base;
> +
> + return bridge;
> +
> +err_create:
> + pci_free_resource_list(&res);
> + return ERR_PTR(err);
> +}
> +EXPORT_SYMBOL_GPL(of_create_pci_host_bridge);
> +
> #ifdef CONFIG_PCI_MSI
>
> static LIST_HEAD(of_pci_msi_chip_list);
> diff --git a/drivers/pci/host-bridge.c b/drivers/pci/host-bridge.c
> index 36c669e..54ceafd 100644
> --- a/drivers/pci/host-bridge.c
> +++ b/drivers/pci/host-bridge.c
> @@ -83,3 +83,18 @@ void pcibios_bus_to_resource(struct pci_bus *bus, struct resource *res,
> res->end = region->end + offset;
> }
> EXPORT_SYMBOL(pcibios_bus_to_resource);
> +
> +/**
> + * Simple version of the platform specific code for filtering the list
> + * of resources obtained from the ranges declaration in DT.
> + *
> + * Platforms can override this function in order to impose stronger
> + * constraints onto the list of resources that a host bridge can use.
> + * The filtered list will then be used to create a root bus and associate
> + * it with the host bridge.
> + *
> + */
> +int __weak pcibios_fixup_bridge_ranges(struct list_head *resources)
> +{
> + return 0;
> +}
> diff --git a/include/linux/of_pci.h b/include/linux/of_pci.h
> index dde3a4a..71e36d0 100644
> --- a/include/linux/of_pci.h
> +++ b/include/linux/of_pci.h
> @@ -15,6 +15,9 @@ struct device_node *of_pci_find_child_device(struct device_node *parent,
> int of_pci_get_devfn(struct device_node *np);
> int of_irq_parse_and_map_pci(const struct pci_dev *dev, u8 slot, u8 pin);
> int of_pci_parse_bus_range(struct device_node *node, struct resource *res);
> +struct pci_host_bridge *of_create_pci_host_bridge(struct device *parent,
> + struct pci_ops *ops, void *host_data);
> +
> #else
> static inline int of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args *out_irq)
> {
> @@ -43,6 +46,13 @@ of_pci_parse_bus_range(struct device_node *node, struct resource *res)
> {
> return -EINVAL;
> }
> +
> +static inline struct pci_host_bridge *
> +of_create_pci_host_bridge(struct device *parent, struct pci_ops *ops,
> + void *host_data)
> +{
> + return NULL;
> +}
> #endif
>
> #if defined(CONFIG_OF) && defined(CONFIG_PCI_MSI)
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 7e7b939..556dc5f 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -402,6 +402,7 @@ struct pci_host_bridge {
> struct device dev;
> struct pci_bus *bus; /* root bus */
> int domain_nr;
> + resource_size_t io_base; /* physical address for the start of I/O area */
> struct list_head windows; /* pci_host_bridge_windows */
> void (*release_fn)(struct pci_host_bridge *);
> void *release_data;
> @@ -1809,8 +1810,15 @@ static inline void pci_set_of_node(struct pci_dev *dev) { }
> static inline void pci_release_of_node(struct pci_dev *dev) { }
> static inline void pci_set_bus_of_node(struct pci_bus *bus) { }
> static inline void pci_release_bus_of_node(struct pci_bus *bus) { }
> +
> #endif /* CONFIG_OF */
>
> +/* Used by architecture code to apply any quirks to the list of
> + * pci_host_bridge resource ranges before they are being used
> + * by of_create_pci_host_bridge()
> + */
> +extern int pcibios_fixup_bridge_ranges(struct list_head *resources);
> +
> #ifdef CONFIG_EEH
> static inline struct eeh_dev *pci_dev_to_eeh_dev(struct pci_dev *pdev)
> {
> --
> 2.0.0
>
>
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