Re: [Patch v7 4/7] PCI/ACPI: Add interface acpi_pci_root_create()

Bjorn Helgaas
2015-10-15T20:47:26Z

On Wed, Oct 14, 2015 at 02:29:39PM +0800, Jiang Liu wrote:
> Introduce common interface acpi_pci_root_create() and related data
> structures to create PCI root bus for ACPI PCI host bridges. It will
> be used to kill duplicated arch specific code for IA64 and x86. It may
> also help ARM64 in future.
>
> Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Tested-by: Tony Luck <tony.luck@intel.com>
> Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
> Signed-off-by: Liu Jiang <jiang.liu@linux.intel.com>

Acked-by: Bjorn Helgaas <bhelgaas@google.com>

> ---
> drivers/acpi/pci_root.c | 204 ++++++++++++++++++++++++++++++++++++++++++++++
> include/linux/pci-acpi.h | 24 ++++++
> 2 files changed, 228 insertions(+)
>
> diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
> index 393706a5261b..850d7bf0c873 100644
> --- a/drivers/acpi/pci_root.c
> +++ b/drivers/acpi/pci_root.c
> @@ -652,6 +652,210 @@ static void acpi_pci_root_remove(struct acpi_device *device)
> kfree(root);
> }
>
> +/*
> + * Following code to support acpi_pci_root_create() is copied from
> + * arch/x86/pci/acpi.c and modified so it could be reused by x86, IA64
> + * and ARM64.
> + */
> +static void acpi_pci_root_validate_resources(struct device *dev,
> + struct list_head *resources,
> + unsigned long type)
> +{
> + LIST_HEAD(list);
> + struct resource *res1, *res2, *root = NULL;
> + struct resource_entry *tmp, *entry, *entry2;
> +
> + BUG_ON((type & (IORESOURCE_MEM | IORESOURCE_IO)) == 0);
> + root = (type & IORESOURCE_MEM) ? &iomem_resource : &ioport_resource;
> +
> + list_splice_init(resources, &list);
> + resource_list_for_each_entry_safe(entry, tmp, &list) {
> + bool free = false;
> + resource_size_t end;
> +
> + res1 = entry->res;
> + if (!(res1->flags & type))
> + goto next;
> +
> + /* Exclude non-addressable range or non-addressable portion */
> + end = min(res1->end, root->end);
> + if (end <= res1->start) {
> + dev_info(dev, "host bridge window %pR (ignored, not CPU addressable)\n",
> + res1);
> + free = true;
> + goto next;
> + } else if (res1->end != end) {
> + dev_info(dev, "host bridge window %pR ([%#llx-%#llx] ignored, not CPU addressable)\n",
> + res1, (unsigned long long)end + 1,
> + (unsigned long long)res1->end);
> + res1->end = end;
> + }
> +
> + resource_list_for_each_entry(entry2, resources) {
> + res2 = entry2->res;
> + if (!(res2->flags & type))
> + continue;
> +
> + /*
> + * I don't like throwing away windows because then
> + * our resources no longer match the ACPI _CRS, but
> + * the kernel resource tree doesn't allow overlaps.
> + */
> + if (resource_overlaps(res1, res2)) {
> + res2->start = min(res1->start, res2->start);
> + res2->end = max(res1->end, res2->end);
> + dev_info(dev, "host bridge window expanded to %pR; %pR ignored\n",
> + res2, res1);
> + free = true;
> + goto next;
> + }
> + }
> +
> +next:
> + resource_list_del(entry);
> + if (free)
> + resource_list_free_entry(entry);
> + else
> + resource_list_add_tail(entry, resources);
> + }
> +}
> +
> +int acpi_pci_probe_root_resources(struct acpi_pci_root_info *info)
> +{
> + int ret;
> + struct list_head *list = &info->resources;
> + struct acpi_device *device = info->bridge;
> + struct resource_entry *entry, *tmp;
> + unsigned long flags;
> +
> + flags = IORESOURCE_IO | IORESOURCE_MEM | IORESOURCE_MEM_8AND16BIT;
> + ret = acpi_dev_get_resources(device, list,
> + acpi_dev_filter_resource_type_cb,
> + (void *)flags);
> + if (ret < 0)
> + dev_warn(&device->dev,
> + "failed to parse _CRS method, error code %d\n", ret);
> + else if (ret == 0)
> + dev_dbg(&device->dev,
> + "no IO and memory resources present in _CRS\n");
> + else {
> + resource_list_for_each_entry_safe(entry, tmp, list) {
> + if (entry->res->flags & IORESOURCE_DISABLED)
> + resource_list_destroy_entry(entry);
> + else
> + entry->res->name = info->name;
> + }
> + acpi_pci_root_validate_resources(&device->dev, list,
> + IORESOURCE_MEM);
> + acpi_pci_root_validate_resources(&device->dev, list,
> + IORESOURCE_IO);
> + }
> +
> + return ret;
> +}
> +
> +static void pci_acpi_root_add_resources(struct acpi_pci_root_info *info)
> +{
> + struct resource_entry *entry, *tmp;
> + struct resource *res, *conflict, *root = NULL;
> +
> + resource_list_for_each_entry_safe(entry, tmp, &info->resources) {
> + res = entry->res;
> + if (res->flags & IORESOURCE_MEM)
> + root = &iomem_resource;
> + else if (res->flags & IORESOURCE_IO)
> + root = &ioport_resource;
> + else
> + continue;
> +
> + conflict = insert_resource_conflict(root, res);
> + if (conflict) {
> + dev_info(&info->bridge->dev,
> + "ignoring host bridge window %pR (conflicts with %s %pR)\n",
> + res, conflict->name, conflict);
> + resource_list_destroy_entry(entry);
> + }
> + }
> +}
> +
> +static void __acpi_pci_root_release_info(struct acpi_pci_root_info *info)
> +{
> + struct resource *res;
> + struct resource_entry *entry, *tmp;
> +
> + if (!info)
> + return;
> +
> + resource_list_for_each_entry_safe(entry, tmp, &info->resources) {
> + res = entry->res;
> + if (res->parent &&
> + (res->flags & (IORESOURCE_MEM | IORESOURCE_IO)))
> + release_resource(res);
> + resource_list_destroy_entry(entry);
> + }
> +
> + info->ops->release_info(info);
> +}
> +
> +static void acpi_pci_root_release_info(struct pci_host_bridge *bridge)
> +{
> + struct resource *res;
> + struct resource_entry *entry;
> +
> + resource_list_for_each_entry(entry, &bridge->windows) {
> + res = entry->res;
> + if (res->parent &&
> + (res->flags & (IORESOURCE_MEM | IORESOURCE_IO)))
> + release_resource(res);
> + }
> + __acpi_pci_root_release_info(bridge->release_data);
> +}
> +
> +struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
> + struct acpi_pci_root_ops *ops,
> + struct acpi_pci_root_info *info,
> + void *sysdata)
> +{
> + int ret, busnum = root->secondary.start;
> + struct acpi_device *device = root->device;
> + int node = acpi_get_node(device->handle);
> + struct pci_bus *bus;
> +
> + info->root = root;
> + info->bridge = device;
> + info->ops = ops;
> + INIT_LIST_HEAD(&info->resources);
> + snprintf(info->name, sizeof(info->name), "PCI Bus %04x:%02x",
> + root->segment, busnum);
> +
> + if (ops->init_info && ops->init_info(info))
> + goto out_release_info;
> + if (ops->prepare_resources)
> + ret = ops->prepare_resources(info);
> + else
> + ret = acpi_pci_probe_root_resources(info);
> + if (ret < 0)
> + goto out_release_info;
> +
> + pci_acpi_root_add_resources(info);
> + pci_add_resource(&info->resources, &root->secondary);
> + bus = pci_create_root_bus(NULL, busnum, ops->pci_ops,
> + sysdata, &info->resources);
> + if (!bus)
> + goto out_release_info;
> +
> + pci_scan_child_bus(bus);
> + pci_set_host_bridge_release(to_pci_host_bridge(bus->bridge),
> + acpi_pci_root_release_info, info);
> + if (node != NUMA_NO_NODE)
> + dev_printk(KERN_DEBUG, &bus->dev, "on NUMA node %d\n", node);
> + return bus;
> +
> +out_release_info:
> + __acpi_pci_root_release_info(info);
> + return NULL;
> +}
> +
> void __init acpi_pci_root_init(void)
> {
> acpi_hest_init();
> diff --git a/include/linux/pci-acpi.h b/include/linux/pci-acpi.h
> index a965efa52152..89ab0572dbc6 100644
> --- a/include/linux/pci-acpi.h
> +++ b/include/linux/pci-acpi.h
> @@ -52,6 +52,30 @@ static inline acpi_handle acpi_pci_get_bridge_handle(struct pci_bus *pbus)
> return ACPI_HANDLE(dev);
> }
>
> +struct acpi_pci_root;
> +struct acpi_pci_root_ops;
> +
> +struct acpi_pci_root_info {
> + struct acpi_pci_root *root;
> + struct acpi_device *bridge;
> + struct acpi_pci_root_ops *ops;
> + struct list_head resources;
> + char name[16];
> +};
> +
> +struct acpi_pci_root_ops {
> + struct pci_ops *pci_ops;
> + int (*init_info)(struct acpi_pci_root_info *info);
> + void (*release_info)(struct acpi_pci_root_info *info);
> + int (*prepare_resources)(struct acpi_pci_root_info *info);
> +};
> +
> +extern int acpi_pci_probe_root_resources(struct acpi_pci_root_info *info);
> +extern struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
> + struct acpi_pci_root_ops *ops,
> + struct acpi_pci_root_info *info,
> + void *sd);
> +
> void acpi_pci_add_bus(struct pci_bus *bus);
> void acpi_pci_remove_bus(struct pci_bus *bus);
>
> --
> 1.7.10.4
>
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