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authorLorenzo Pieralisi <lorenzo.pieralisi@arm.com>2017-04-19 17:48:55 +0100
committerBjorn Helgaas <bhelgaas@google.com>2017-04-24 13:53:13 -0500
commit490cb6ddb17df5ef5f5eb33c9a34f3033b31c204 (patch)
tree7c3b684679bae3d890199b330bb18b3c744b7497 /drivers/pci
parent6524754eff305760d0b31dac468e78057a56f47e (diff)
PCI: Implement devm_pci_remap_cfgspace()
The introduction of the pci_remap_cfgspace() interface allows PCI host controller drivers to map PCI config space through a dedicated kernel interface. Current PCI host controller drivers use the devm_ioremap_*() devres interfaces to map PCI configuration space regions so in order to update them to the new pci_remap_cfgspace() mapping interface a new set of devres interfaces should be implemented so that PCI host controller drivers can make use of them. Introduce two new functions in the PCI kernel layer and Devres documentation: - devm_pci_remap_cfgspace() - devm_pci_remap_cfg_resource() so that PCI host controller drivers can make use of them to map PCI configuration space regions. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Cc: Jonathan Corbet <corbet@lwn.net>
Diffstat (limited to 'drivers/pci')
-rw-r--r--drivers/pci/pci.c82
1 files changed, 82 insertions, 0 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index bd98674a0419..4129f9453861 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -3401,6 +3401,88 @@ void pci_unmap_iospace(struct resource *res)
#endif
}
+/**
+ * devm_pci_remap_cfgspace - Managed pci_remap_cfgspace()
+ * @dev: Generic device to remap IO address for
+ * @offset: Resource address to map
+ * @size: Size of map
+ *
+ * Managed pci_remap_cfgspace(). Map is automatically unmapped on driver
+ * detach.
+ */
+void __iomem *devm_pci_remap_cfgspace(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 = pci_remap_cfgspace(offset, size);
+ if (addr) {
+ *ptr = addr;
+ devres_add(dev, ptr);
+ } else
+ devres_free(ptr);
+
+ return addr;
+}
+EXPORT_SYMBOL(devm_pci_remap_cfgspace);
+
+/**
+ * devm_pci_remap_cfg_resource - check, request region and ioremap cfg resource
+ * @dev: generic device to handle the resource for
+ * @res: configuration space resource to be handled
+ *
+ * Checks that a resource is a valid memory region, requests the memory
+ * region and ioremaps with pci_remap_cfgspace() API that ensures the
+ * proper PCI configuration space memory attributes are guaranteed.
+ *
+ * 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_pci_remap_cfg_resource(&pdev->dev, res);
+ * if (IS_ERR(base))
+ * return PTR_ERR(base);
+ */
+void __iomem *devm_pci_remap_cfg_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_pci_remap_cfgspace(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_pci_remap_cfg_resource);
+
static void __pci_set_master(struct pci_dev *dev, bool enable)
{
u16 old_cmd, cmd;