Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1626544

[PATCH v4 06/21] PCI: implement Devres interface to map PCI config space

Show all headers | View raw

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>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Bjorn Helgaas <bhelgaas@google.com>
---
 Documentation/driver-model/devres.txt |  6 ++-
 drivers/pci/pci.c                     | 82 +++++++++++++++++++++++++++++++++++
 include/linux/pci.h                   |  5 +++
 3 files changed, 91 insertions(+), 2 deletions(-)

diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt
index bf34d5b..e72587f 100644
--- a/Documentation/driver-model/devres.txt
+++ b/Documentation/driver-model/devres.txt
@@ -342,8 +342,10 @@ PER-CPU MEM
   devm_free_percpu()
 
 PCI
-  pcim_enable_device()	: after success, all PCI ops become managed
-  pcim_pin_device()	: keep PCI device enabled after release
+  devm_pci_remap_cfgspace()	: ioremap PCI configuration space
+  devm_pci_remap_cfg_resource()	: ioremap PCI configuration space resource
+  pcim_enable_device()		: after success, all PCI ops become managed
+  pcim_pin_device()		: keep PCI device enabled after release
 
 PHY
   devm_usb_get_phy()
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index bd98674..4129f94 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;
diff --git a/include/linux/pci.h b/include/linux/pci.h
index eb3da1a..70534d6 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1199,6 +1199,11 @@ unsigned long pci_address_to_pio(phys_addr_t addr);
 phys_addr_t pci_pio_to_address(unsigned long pio);
 int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr);
 void pci_unmap_iospace(struct resource *res);
+void __iomem *devm_pci_remap_cfgspace(struct device *dev,
+				      resource_size_t offset,
+				      resource_size_t size);
+void __iomem *devm_pci_remap_cfg_resource(struct device *dev,
+					  struct resource *res);
 
 static inline pci_bus_addr_t pci_bus_address(struct pci_dev *pdev, int bar)
 {
-- 
2.10.0

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH v4 00/21] PCI: fix config space memory mappings Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> - 2017-04-19 19:00 +0200
  [PATCH v4 20/21] PCI: keystone-dw: update PCI config space remap function Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> - 2017-04-19 19:00 +0200
  [PATCH v4 17/21] PCI: tegra: update PCI config space remap function Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> - 2017-04-19 19:00 +0200
  [PATCH v4 06/21] PCI: implement Devres interface to map PCI config space Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> - 2017-04-19 19:00 +0200
  [PATCH v4 15/21] PCI: armada8k: update PCI config space remap function Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> - 2017-04-19 19:00 +0200
  [PATCH v4 12/21] PCI: qcom: update PCI config space remap function Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> - 2017-04-19 19:00 +0200
  [PATCH v4 19/21] PCI: layerscape: update PCI config space remap function Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> - 2017-04-19 19:00 +0200
  [PATCH v4 16/21] PCI: xgene: update PCI config space remap function Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> - 2017-04-19 19:00 +0200
  [PATCH v4 11/21] PCI: rockchip: update PCI config space remap function Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> - 2017-04-19 19:00 +0200
  [PATCH v4 07/21] PCI: ECAM: use pci_remap_cfgspace() to map config region Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> - 2017-04-19 19:00 +0200
  [PATCH v4 03/21] ARM64: implement pci_remap_cfgspace() interface Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> - 2017-04-19 19:00 +0200
    Re: [PATCH v4 03/21] ARM64: implement pci_remap_cfgspace() interface Catalin Marinas <catalin.marinas@arm.com> - 2017-04-20 12:40 +0200
  [PATCH v4 13/21] PCI: iproc-platform: update PCI config space remap function Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> - 2017-04-19 19:00 +0200
  [PATCH v4 18/21] PCI: hisi: update PCI config space remap function Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> - 2017-04-19 19:00 +0200
  [PATCH v4 21/21] PCI: versatile: update PCI config space remap function Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> - 2017-04-19 19:00 +0200
  Re: [PATCH v4 00/21] PCI: fix config space memory mappings Bjorn Helgaas <helgaas@kernel.org> - 2017-04-20 15:30 +0200

csiph-web