This patch series introduces OF overlay support for PCI devices which
primarily addresses two use cases. First, it provides a data driven method
to describe hardware peripherals that are present in a PCI endpoint and
hence can be accessed by the PCI host. Second, it allows reuse of a OF
compatible driver -- often used in SoC platforms -- in a PCI host based
system.
There are 2 series devices rely on this patch:
1) Xilinx Alveo Accelerator cards (FPGA based device)
2) Microchip LAN9662 Ethernet Controller
Please see: https://lore.kernel.org/lkml/[email protected]/
Normally, the PCI core discovers PCI devices and their BARs using the
PCI enumeration process. However, the process does not provide a way to
discover the hardware peripherals that are present in a PCI device, and
which can be accessed through the PCI BARs. Also, the enumeration process
does not provide a way to associate MSI-X vectors of a PCI device with the
hardware peripherals that are present in the device. PCI device drivers
often use header files to describe the hardware peripherals and their
resources as there is no standard data driven way to do so. This patch
series proposes to use flattened device tree blob to describe the
peripherals in a data driven way. Based on previous discussion, using
device tree overlay is the best way to unflatten the blob and populate
platform devices. To use device tree overlay, there are three obvious
problems that need to be resolved.
First, we need to create a base tree for non-DT system such as x86_64. A
patch series has been submitted for this:
https://lore.kernel.org/lkml/[email protected]/
https://lore.kernel.org/lkml/[email protected]/
Second, a device tree node corresponding to the PCI endpoint is required
for overlaying the flattened device tree blob for that PCI endpoint.
Because PCI is a self-discoverable bus, a device tree node is usually not
created for PCI devices. This series adds support to generate a device
tree node for a PCI device which advertises itself using PCI quirks
infrastructure.
Third, we need to generate device tree nodes for PCI bridges since a child
PCI endpoint may choose to have a device tree node created.
This patch series is made up of three patches.
The first patch is adding OF interface to create or destroy OF node
dynamically.
The second patch introduces a kernel option, CONFIG_DYNAMIC_PCI_OF_NODEX.
When the option is turned on, the kernel will generate device tree nodes
for all PCI bridges unconditionally. The patch also shows how to use the
PCI quirks infrastructure, DECLARE_PCI_FIXUP_FINAL to generate a device
tree node for a device. Specifically, the patch generates a device tree
node for Xilinx Alveo U50 PCIe accelerator device. The generated device
tree nodes do not have any property.
The third patch adds basic properties ('reg', 'compatible' and
'device_type') to the dynamically generated device tree nodes. More
properties can be added in the future.
Here is the example of device tree nodes generated within the ARM64 QEMU.
# lspci -t
-[0000:00]-+-00.0
+-01.0-[01]--
+-01.1-[02]----00.0
+-01.2-[03]----00.0
+-01.3-[04]----00.0
+-01.4-[05]----00.0
+-01.5-[06]--
+-01.6-[07]--
+-01.7-[08]--
+-02.0-[09-0b]----00.0-[0a-0b]----00.0-[0b]--+-00.0
| \-00.1
+-02.1-[0c]--
\-03.0-[0d-0e]----00.0-[0e]----01.0
# tree /sys/firmware/devicetree/base/pcie\@10000000
/sys/firmware/devicetree/base/pcie@10000000
|-- #address-cells
|-- #interrupt-cells
|-- #size-cells
|-- bus-range
|-- compatible
|-- device_type
|-- dma-coherent
|-- interrupt-map
|-- interrupt-map-mask
|-- linux,pci-domain
|-- msi-parent
|-- name
|-- pci@1,0
| |-- #address_cells
| |-- #size_cells
| |-- compatible
| |-- device_type
| |-- ranges
| `-- reg
|-- pci@1,1
| |-- #address_cells
| |-- #size_cells
| |-- compatible
| |-- device_type
| |-- ranges
| `-- reg
|-- pci@1,2
| |-- #address_cells
| |-- #size_cells
| |-- compatible
| |-- device_type
| |-- ranges
| `-- reg
|-- pci@1,3
| |-- #address_cells
| |-- #size_cells
| |-- compatible
| |-- device_type
| |-- ranges
| `-- reg
|-- pci@1,4
| |-- #address_cells
| |-- #size_cells
| |-- compatible
| |-- device_type
| |-- ranges
| `-- reg
|-- pci@1,5
| |-- #address_cells
| |-- #size_cells
| |-- compatible
| |-- device_type
| |-- ranges
| `-- reg
|-- pci@1,6
| |-- #address_cells
| |-- #size_cells
| |-- compatible
| |-- device_type
| |-- ranges
| `-- reg
|-- pci@1,7
| |-- #address_cells
| |-- #size_cells
| |-- compatible
| |-- device_type
| |-- ranges
| `-- reg
|-- pci@2,0
| |-- #address_cells
| |-- #size_cells
| |-- compatible
| |-- device_type
| |-- pci@0,0
| | |-- #address_cells
| | |-- #size_cells
| | |-- compatible
| | |-- device_type
| | |-- pci@0,0
| | | |-- #address_cells
| | | |-- #size_cells
| | | |-- compatible
| | | |-- dev@0,0
| | | | |-- compatible
| | | | `-- reg
| | | |-- dev@0,1
| | | | |-- compatible
| | | | `-- reg
| | | |-- device_type
| | | |-- ranges
| | | `-- reg
| | |-- ranges
| | `-- reg
| |-- ranges
| `-- reg
|-- pci@2,1
| |-- #address_cells
| |-- #size_cells
| |-- compatible
| |-- device_type
| |-- ranges
| `-- reg
|-- pci@3,0
| |-- #address_cells
| |-- #size_cells
| |-- compatible
| |-- device_type
| |-- pci@0,0
| | |-- #address_cells
| | |-- #size_cells
| | |-- compatible
| | |-- device_type
| | |-- ranges
| | `-- reg
| |-- ranges
| `-- reg
|-- ranges
`-- reg
Changes since RFC v4:
- Fixed code review comments
Changes since RFC v3:
- Split the Xilinx Alveo U50 PCI quirk to a separate patch
- Minor changes in commit description and code comment
Changes since RFC v2:
- Merged patch 3 with patch 2
- Added OF interfaces of_changeset_add_prop_* and use them to create
properties.
- Added '#address-cells', '#size-cells' and 'ranges' properties.
Changes since RFC v1:
- Added one patch to create basic properties.
- To move DT related code out of PCI subsystem, replaced of_node_alloc()
with of_create_node()/of_destroy_node()
Lizhi Hou (3):
of: dynamic: Add interfaces for creating device node dynamically
PCI: Create device tree node for selected devices
PCI: Add PCI quirks to generate device tree node for Xilinx Alveo U50
drivers/of/dynamic.c | 197 ++++++++++++++++++++++++++++++++
drivers/pci/Kconfig | 12 ++
drivers/pci/Makefile | 1 +
drivers/pci/bus.c | 2 +
drivers/pci/msi/irqdomain.c | 6 +-
drivers/pci/of.c | 71 ++++++++++++
drivers/pci/of_property.c | 222 ++++++++++++++++++++++++++++++++++++
drivers/pci/pci-driver.c | 3 +-
drivers/pci/pci.h | 19 +++
drivers/pci/quirks.c | 11 ++
drivers/pci/remove.c | 1 +
include/linux/of.h | 24 ++++
12 files changed, 566 insertions(+), 3 deletions(-)
create mode 100644 drivers/pci/of_property.c
--
2.17.1
of_create_node() creates device node dynamically. The parent device node
and full name are required for creating the node. It optionally creates
an OF changeset and attaches the newly created node to the changeset. The
device node pointer and the changeset pointer can be used to add
properties to the device node and apply the node to the base tree.
of_destroy_node() frees the device node created by of_create_node(). If
an OF changeset was also created for this node, it will destroy the
changeset before freeing the device node.
Expand of_changeset APIs to handle specific types of properties.
of_changeset_add_prop_string()
of_changeset_add_prop_string_array()
of_changeset_add_prop_u32_array()
Signed-off-by: Lizhi Hou <[email protected]>
Signed-off-by: Sonal Santan <[email protected]>
Signed-off-by: Max Zhen <[email protected]>
Reviewed-by: Brian Xu <[email protected]>
---
drivers/of/dynamic.c | 197 +++++++++++++++++++++++++++++++++++++++++++
include/linux/of.h | 24 ++++++
2 files changed, 221 insertions(+)
diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
index cd3821a6444f..067d996a9f79 100644
--- a/drivers/of/dynamic.c
+++ b/drivers/of/dynamic.c
@@ -461,6 +461,71 @@ struct device_node *__of_node_dup(const struct device_node *np,
return NULL;
}
+/**
+ * of_create_node - Dynamically create a device node
+ *
+ * @parent: Pointer to parent device node
+ * @full_name: Node full name
+ * @cset: Pointer to returning changeset
+ *
+ * Return: Pointer to the created device node or NULL in case of an error.
+ */
+struct device_node *of_create_node(struct device_node *parent,
+ const char *full_name,
+ struct of_changeset **cset)
+{
+ struct of_changeset *ocs;
+ struct device_node *np;
+ int ret;
+
+ np = __of_node_dup(NULL, full_name);
+ if (!np)
+ return NULL;
+ np->parent = parent;
+
+ if (!cset)
+ return np;
+
+ ocs = kmalloc(sizeof(*cset), GFP_KERNEL);
+ if (!ocs) {
+ of_node_put(np);
+ return NULL;
+ }
+
+ of_changeset_init(ocs);
+ ret = of_changeset_attach_node(ocs, np);
+ if (ret) {
+ of_changeset_destroy(ocs);
+ of_node_put(np);
+ kfree(ocs);
+ return NULL;
+ }
+
+ np->data = ocs;
+ *cset = ocs;
+
+ return np;
+}
+EXPORT_SYMBOL(of_create_node);
+
+/**
+ * of_destroy_node - Destroy a dynamically created device node
+ *
+ * @np: Pointer to dynamically created device node
+ *
+ */
+void of_destroy_node(struct device_node *np)
+{
+ struct of_changeset *ocs;
+
+ if (np->data) {
+ ocs = (struct of_changeset *)np->data;
+ of_changeset_destroy(ocs);
+ }
+ of_node_put(np);
+}
+EXPORT_SYMBOL(of_destroy_node);
+
static void __of_changeset_entry_destroy(struct of_changeset_entry *ce)
{
if (ce->action == OF_RECONFIG_ATTACH_NODE &&
@@ -934,3 +999,135 @@ int of_changeset_action(struct of_changeset *ocs, unsigned long action,
return 0;
}
EXPORT_SYMBOL_GPL(of_changeset_action);
+
+static int of_changeset_add_prop_helper(struct of_changeset *ocs,
+ struct device_node *np,
+ const struct property *pp)
+{
+ struct property *new_pp;
+ int ret;
+
+ new_pp = __of_prop_dup(pp, GFP_KERNEL);
+ if (!new_pp)
+ return -ENOMEM;
+
+ ret = of_changeset_add_property(ocs, np, new_pp);
+ if (ret) {
+ kfree(new_pp->name);
+ kfree(new_pp->value);
+ kfree(new_pp);
+ }
+
+ return ret;
+}
+
+/**
+ * of_changeset_add_prop_string - Add a string property to a changeset
+ *
+ * @ocs: changeset pointer
+ * @np: device node pointer
+ * @prop_name: name of the property to be added
+ * @str: pointer to null terminated string
+ *
+ * Create a string property and add it to a changeset.
+ *
+ * Return: 0 on success, a negative error value in case of an error.
+ */
+int of_changeset_add_prop_string(struct of_changeset *ocs,
+ struct device_node *np,
+ const char *prop_name, const char *str)
+{
+ struct property prop;
+
+ prop.name = (char *)prop_name;
+ prop.length = strlen(str) + 1;
+ prop.value = (void *)str;
+
+ return of_changeset_add_prop_helper(ocs, np, &prop);
+}
+EXPORT_SYMBOL_GPL(of_changeset_add_prop_string);
+
+/**
+ * of_changeset_add_prop_string_array - Add a string list property to
+ * a changeset
+ *
+ * @ocs: changeset pointer
+ * @np: device node pointer
+ * @prop_name: name of the property to be added
+ * @str_array: pointer to an array of null terminated strings
+ * @sz: number of string array elements
+ *
+ * Create a string list property and add it to a changeset.
+ *
+ * Return: 0 on success, a negative error value in case of an error.
+ */
+int of_changeset_add_prop_string_array(struct of_changeset *ocs,
+ struct device_node *np,
+ const char *prop_name,
+ const char **str_array, size_t sz)
+{
+ struct property prop;
+ int i, ret;
+ char *vp;
+
+ prop.name = (char *)prop_name;
+
+ prop.length = 0;
+ for (i = 0; i < sz; i++)
+ prop.length += strlen(str_array[i]) + 1;
+
+ prop.value = kmalloc(prop.length, GFP_KERNEL);
+ if (!prop.value)
+ return -ENOMEM;
+
+ vp = prop.value;
+ for (i = 0; i < sz; i++) {
+ vp += snprintf(vp, (char *)prop.value + prop.length - vp, "%s",
+ str_array[i]) + 1;
+ }
+ ret = of_changeset_add_prop_helper(ocs, np, &prop);
+ kfree(prop.value);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(of_changeset_add_prop_string_array);
+
+/**
+ * of_changeset_add_prop_u32_array - Add a property of 32 bit integers
+ * property to a changeset
+ *
+ * @ocs: changeset pointer
+ * @np: device node pointer
+ * @prop_name: name of the property to be added
+ * @array: pointer to an array of 32 bit integers
+ * @sz: number of array elements
+ *
+ * Create a property of 32 bit integers and add it to a changeset.
+ *
+ * Return: 0 on success, a negative error value in case of an error.
+ */
+int of_changeset_add_prop_u32_array(struct of_changeset *ocs,
+ struct device_node *np,
+ const char *prop_name,
+ const u32 *array, size_t sz)
+{
+ struct property prop;
+ __be32 *val;
+ int i, ret;
+
+ val = kcalloc(sz, sizeof(__be32), GFP_KERNEL);
+ if (!val)
+ return -ENOMEM;
+
+ for (i = 0; i < sz; i++)
+ val[i] = cpu_to_be32(array[i]);
+ prop.name = (char *)prop_name;
+ prop.length = sizeof(u32) * sz;
+ prop.value = (void *)val;
+
+ ret = of_changeset_add_prop_helper(ocs, np, &prop);
+ kfree(val);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(of_changeset_add_prop_u32_array);
diff --git a/include/linux/of.h b/include/linux/of.h
index 766d002bddb9..ba31036f0876 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -1505,6 +1505,30 @@ static inline int of_changeset_update_property(struct of_changeset *ocs,
{
return of_changeset_action(ocs, OF_RECONFIG_UPDATE_PROPERTY, np, prop);
}
+
+struct device_node *of_create_node(struct device_node *parent,
+ const char *full_name,
+ struct of_changeset **cset);
+void of_destroy_node(struct device_node *np);
+int of_changeset_add_prop_string(struct of_changeset *ocs,
+ struct device_node *np,
+ const char *prop_name, const char *str);
+int of_changeset_add_prop_string_array(struct of_changeset *ocs,
+ struct device_node *np,
+ const char *prop_name,
+ const char **str_array, size_t sz);
+int of_changeset_add_prop_u32_array(struct of_changeset *ocs,
+ struct device_node *np,
+ const char *prop_name,
+ const u32 *array, size_t sz);
+static inline int of_changeset_add_prop_u32(struct of_changeset *ocs,
+ struct device_node *np,
+ const char *prop_name,
+ const u32 val)
+{
+ return of_changeset_add_prop_u32_array(ocs, np, prop_name, &val, 1);
+}
+
#else /* CONFIG_OF_DYNAMIC */
static inline int of_reconfig_notifier_register(struct notifier_block *nb)
{
--
2.17.1