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_PCI_DYNAMIC_OF_NODES.
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
+-03.0-[01-03]----00.0-[02-03]----00.0-[03]----00.0
+-03.1-[04]--
\-04.0-[05-06]----00.0-[06]--
Without CONFIG_PCI_DYNAMIC_OF_NODES
# 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-map
|-- name
|-- ranges
`-- reg
With CONFIG_PCI_DYNAMIC_OF_NODES
# 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-map
|-- name
|-- pci@3,0
| |-- #address-cells
| |-- #size-cells
| |-- bus-range
| |-- compatible
| |-- device_type
| |-- pci@0,0
| | |-- #address-cells
| | |-- #size-cells
| | |-- bus-range
| | |-- compatible
| | |-- device_type
| | |-- pci@0,0
| | | |-- #address-cells
| | | |-- #size-cells
| | | |-- bus-range
| | | |-- compatible
| | | |-- dev@0,0
| | | | |-- #address-cells
| | | | |-- #size-cells
| | | | |-- compatible
| | | | |-- ranges
| | | | `-- reg
| | | |-- device_type
| | | |-- ranges
| | | `-- reg
| | |-- ranges
| | `-- reg
| |-- ranges
| `-- reg
|-- pci@3,1
| |-- #address-cells
| |-- #size-cells
| |-- bus-range
| |-- compatible
| |-- device_type
| |-- ranges
| `-- reg
|-- pci@4,0
| |-- #address-cells
| |-- #size-cells
| |-- bus-range
| |-- compatible
| |-- device_type
| |-- pci@0,0
| | |-- #address-cells
| | |-- #size-cells
| | |-- bus-range
| | |-- compatible
| | |-- device_type
| | |-- ranges
| | `-- reg
| |-- ranges
| `-- reg
|-- ranges
`-- reg
Changes since v10:
- Remove 'dynamic' property
Changes since v9:
- Introduce 'dynamic' property to identify dynamically generated device tree
node for PCI device
- Added 'bus-range' property to remove dtc warnings
- Minor code review fixes
Changes since v8:
- Added patches to create unit test to verifying address translation
The test relies on QEMU PCI Test Device, please see
https://github.com/houlz0507/xoclv2/blob/pci-dt-0329/pci-dt-patch-0329/README
for test setup
- Minor code review fixes
Changes since v7:
- Modified dynamic node creation interfaces
- Added unittest for new added interfaces
Changes since v6:
- Removed single line wrapper functions
- Added Signed-off-by Clément Léger <[email protected]>
Changes since v5:
- Fixed code review comments
- Fixed incorrect 'ranges' and 'reg' properties
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 (5):
of: dynamic: Add interfaces for creating device node dynamically
PCI: Create device tree node for bridge
PCI: Add quirks to generate device tree node for Xilinx Alveo U50
of: overlay: Extend of_overlay_fdt_apply() to specify the target node
of: unittest: Add pci_dt_testdrv pci driver
drivers/of/dynamic.c | 164 +++++++++++++
drivers/of/overlay.c | 42 +++-
drivers/of/unittest-data/Makefile | 3 +-
.../of/unittest-data/overlay_pci_node.dtso | 22 ++
drivers/of/unittest.c | 211 +++++++++++++++-
drivers/pci/Kconfig | 12 +
drivers/pci/Makefile | 1 +
drivers/pci/bus.c | 2 +
drivers/pci/of.c | 96 +++++++-
drivers/pci/of_property.c | 232 ++++++++++++++++++
drivers/pci/pci.h | 12 +
drivers/pci/quirks.c | 12 +
drivers/pci/remove.c | 1 +
include/linux/of.h | 25 +-
14 files changed, 818 insertions(+), 17 deletions(-)
create mode 100644 drivers/of/unittest-data/overlay_pci_node.dtso
create mode 100644 drivers/pci/of_property.c
--
2.34.1
of_changeset_create_node() creates device node dynamically and attaches
the newly created node to a changeset.
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: Clément Léger <[email protected]>
Signed-off-by: Lizhi Hou <[email protected]>
---
drivers/of/dynamic.c | 164 ++++++++++++++++++++++++++++++++++++++++++
drivers/of/unittest.c | 19 ++++-
include/linux/of.h | 23 ++++++
3 files changed, 205 insertions(+), 1 deletion(-)
diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
index e311d406b170..9259cebda4d6 100644
--- a/drivers/of/dynamic.c
+++ b/drivers/of/dynamic.c
@@ -487,6 +487,38 @@ struct device_node *__of_node_dup(const struct device_node *np,
return NULL;
}
+/**
+ * of_changeset_create_node - Dynamically create a device node and attach to
+ * a given changeset.
+ *
+ * @parent: Pointer to parent device node
+ * @full_name: Node full name
+ * @cset: Pointer to changeset
+ *
+ * Return: Pointer to the created device node or NULL in case of an error.
+ */
+struct device_node *of_changeset_create_node(struct device_node *parent,
+ const char *full_name,
+ struct of_changeset *cset)
+{
+ struct device_node *np;
+ int ret;
+
+ np = __of_node_dup(NULL, full_name);
+ if (!np)
+ return NULL;
+ np->parent = parent;
+
+ ret = of_changeset_attach_node(cset, np);
+ if (ret) {
+ of_node_put(np);
+ return NULL;
+ }
+
+ return np;
+}
+EXPORT_SYMBOL(of_changeset_create_node);
+
static void __of_changeset_entry_destroy(struct of_changeset_entry *ce)
{
if (ce->action == OF_RECONFIG_ATTACH_NODE &&
@@ -960,3 +992,135 @@ 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/drivers/of/unittest.c b/drivers/of/unittest.c
index a406a12eb208..d2b286d32db0 100644
--- a/drivers/of/unittest.c
+++ b/drivers/of/unittest.c
@@ -802,7 +802,9 @@ static void __init of_unittest_changeset(void)
struct property *ppname_n21, pname_n21 = { .name = "name", .length = 3, .value = "n21" };
struct property *ppupdate, pupdate = { .name = "prop-update", .length = 5, .value = "abcd" };
struct property *ppremove;
- struct device_node *n1, *n2, *n21, *nchangeset, *nremove, *parent, *np;
+ struct device_node *n1, *n2, *n21, *n22, *nchangeset, *nremove, *parent, *np;
+ static const char * const str_array[] = { "str1", "str2", "str3" };
+ const u32 u32_array[] = { 1, 2, 3 };
struct of_changeset chgset;
n1 = __of_node_dup(NULL, "n1");
@@ -857,6 +859,17 @@ static void __init of_unittest_changeset(void)
unittest(!of_changeset_add_property(&chgset, parent, ppadd), "fail add prop prop-add\n");
unittest(!of_changeset_update_property(&chgset, parent, ppupdate), "fail update prop\n");
unittest(!of_changeset_remove_property(&chgset, parent, ppremove), "fail remove prop\n");
+ n22 = of_changeset_create_node(n2, "n22", &chgset);
+ unittest(n22, "fail create n22\n");
+ unittest(!of_changeset_add_prop_string(&chgset, n22, "prop-str", "abcd"),
+ "fail add prop prop-str");
+ unittest(!of_changeset_add_prop_string_array(&chgset, n22, "prop-str-array",
+ (const char **)str_array,
+ ARRAY_SIZE(str_array)),
+ "fail add prop prop-str-array");
+ unittest(!of_changeset_add_prop_u32_array(&chgset, n22, "prop-u32-array",
+ u32_array, ARRAY_SIZE(u32_array)),
+ "fail add prop prop-u32-array");
unittest(!of_changeset_apply(&chgset), "apply failed\n");
@@ -866,6 +879,9 @@ static void __init of_unittest_changeset(void)
unittest((np = of_find_node_by_path("/testcase-data/changeset/n2/n21")),
"'%pOF' not added\n", n21);
of_node_put(np);
+ unittest((np = of_find_node_by_path("/testcase-data/changeset/n2/n22")),
+ "'%pOF' not added\n", n22);
+ of_node_put(np);
unittest(!of_changeset_revert(&chgset), "revert failed\n");
@@ -874,6 +890,7 @@ static void __init of_unittest_changeset(void)
of_node_put(n1);
of_node_put(n2);
of_node_put(n21);
+ of_node_put(n22);
#endif
}
diff --git a/include/linux/of.h b/include/linux/of.h
index 6ecde0515677..82d0a476ec75 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -1580,6 +1580,29 @@ 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_changeset_create_node(struct device_node *parent,
+ const char *full_name,
+ struct of_changeset *cset);
+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)
{
--
2.34.1
Currently, in an overlay fdt fragment, it needs to specify the exact
location in base DT. In another word, when the fdt fragment is generated,
the base DT location for the fragment is already known.
There is new use case that the base DT location is unknown when fdt
fragment is generated. For example, the add-on device provide a fdt
overlay with its firmware to describe its downstream devices. Because it
is add-on device which can be plugged to different systems, its firmware
will not be able to know the overlay location in base DT. Instead, the
device driver will load the overlay fdt and apply it to base DT at runtime.
In this case, of_overlay_fdt_apply() needs to be extended to specify
the target node for device driver to apply overlay fdt.
int overlay_fdt_apply(..., struct device_node *base);
Signed-off-by: Lizhi Hou <[email protected]>
---
drivers/of/overlay.c | 42 +++++++++++++++++++++++++++++++-----------
drivers/of/unittest.c | 3 ++-
include/linux/of.h | 2 +-
3 files changed, 34 insertions(+), 13 deletions(-)
diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
index 7feb643f1370..6f3ae30c878d 100644
--- a/drivers/of/overlay.c
+++ b/drivers/of/overlay.c
@@ -682,9 +682,11 @@ static int build_changeset(struct overlay_changeset *ovcs)
* 1) "target" property containing the phandle of the target
* 2) "target-path" property containing the path of the target
*/
-static struct device_node *find_target(struct device_node *info_node)
+static struct device_node *find_target(struct device_node *info_node,
+ struct device_node *target_base)
{
struct device_node *node;
+ char *target_path;
const char *path;
u32 val;
int ret;
@@ -700,10 +702,23 @@ static struct device_node *find_target(struct device_node *info_node)
ret = of_property_read_string(info_node, "target-path", &path);
if (!ret) {
- node = of_find_node_by_path(path);
- if (!node)
- pr_err("find target, node: %pOF, path '%s' not found\n",
- info_node, path);
+ if (target_base) {
+ target_path = kasprintf(GFP_KERNEL, "%pOF%s", target_base, path);
+ if (!target_path)
+ return NULL;
+ node = of_find_node_by_path(target_path);
+ if (!node) {
+ pr_err("find target, node: %pOF, path '%s' not found\n",
+ info_node, target_path);
+ }
+ kfree(target_path);
+ } else {
+ node = of_find_node_by_path(path);
+ if (!node) {
+ pr_err("find target, node: %pOF, path '%s' not found\n",
+ info_node, path);
+ }
+ }
return node;
}
@@ -715,6 +730,7 @@ static struct device_node *find_target(struct device_node *info_node)
/**
* init_overlay_changeset() - initialize overlay changeset from overlay tree
* @ovcs: Overlay changeset to build
+ * @target_base: Point to the target node to apply overlay
*
* Initialize @ovcs. Populate @ovcs->fragments with node information from
* the top level of @overlay_root. The relevant top level nodes are the
@@ -725,7 +741,8 @@ static struct device_node *find_target(struct device_node *info_node)
* detected in @overlay_root. On error return, the caller of
* init_overlay_changeset() must call free_overlay_changeset().
*/
-static int init_overlay_changeset(struct overlay_changeset *ovcs)
+static int init_overlay_changeset(struct overlay_changeset *ovcs,
+ struct device_node *target_base)
{
struct device_node *node, *overlay_node;
struct fragment *fragment;
@@ -786,7 +803,7 @@ static int init_overlay_changeset(struct overlay_changeset *ovcs)
fragment = &fragments[cnt];
fragment->overlay = overlay_node;
- fragment->target = find_target(node);
+ fragment->target = find_target(node, target_base);
if (!fragment->target) {
of_node_put(fragment->overlay);
ret = -EINVAL;
@@ -877,6 +894,7 @@ static void free_overlay_changeset(struct overlay_changeset *ovcs)
*
* of_overlay_apply() - Create and apply an overlay changeset
* @ovcs: overlay changeset
+ * @base: point to the target node to apply overlay
*
* Creates and applies an overlay changeset.
*
@@ -900,7 +918,8 @@ static void free_overlay_changeset(struct overlay_changeset *ovcs)
* the caller of of_overlay_apply() must call free_overlay_changeset().
*/
-static int of_overlay_apply(struct overlay_changeset *ovcs)
+static int of_overlay_apply(struct overlay_changeset *ovcs,
+ struct device_node *base)
{
int ret = 0, ret_revert, ret_tmp;
@@ -908,7 +927,7 @@ static int of_overlay_apply(struct overlay_changeset *ovcs)
if (ret)
goto out;
- ret = init_overlay_changeset(ovcs);
+ ret = init_overlay_changeset(ovcs, base);
if (ret)
goto out;
@@ -952,6 +971,7 @@ static int of_overlay_apply(struct overlay_changeset *ovcs)
* @overlay_fdt: pointer to overlay FDT
* @overlay_fdt_size: number of bytes in @overlay_fdt
* @ret_ovcs_id: pointer for returning created changeset id
+ * @base: pointer for the target node to apply overlay
*
* Creates and applies an overlay changeset.
*
@@ -967,7 +987,7 @@ static int of_overlay_apply(struct overlay_changeset *ovcs)
*/
int of_overlay_fdt_apply(const void *overlay_fdt, u32 overlay_fdt_size,
- int *ret_ovcs_id)
+ int *ret_ovcs_id, struct device_node *base)
{
void *new_fdt;
void *new_fdt_align;
@@ -1037,7 +1057,7 @@ int of_overlay_fdt_apply(const void *overlay_fdt, u32 overlay_fdt_size,
}
ovcs->overlay_mem = overlay_mem;
- ret = of_overlay_apply(ovcs);
+ ret = of_overlay_apply(ovcs, base);
/*
* If of_overlay_apply() error, calling free_overlay_changeset() may
* result in a memory leak if the apply partly succeeded, so do NOT
diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c
index d2b286d32db0..7bff6c4cb653 100644
--- a/drivers/of/unittest.c
+++ b/drivers/of/unittest.c
@@ -3478,7 +3478,8 @@ static int __init overlay_data_apply(const char *overlay_name, int *ovcs_id)
if (!size)
pr_err("no overlay data for %s\n", overlay_name);
- ret = of_overlay_fdt_apply(info->dtbo_begin, size, &info->ovcs_id);
+ ret = of_overlay_fdt_apply(info->dtbo_begin, size, &info->ovcs_id,
+ NULL);
if (ovcs_id)
*ovcs_id = info->ovcs_id;
if (ret < 0)
diff --git a/include/linux/of.h b/include/linux/of.h
index 82d0a476ec75..5fe5257a7ab7 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -1668,7 +1668,7 @@ struct of_overlay_notify_data {
#ifdef CONFIG_OF_OVERLAY
int of_overlay_fdt_apply(const void *overlay_fdt, u32 overlay_fdt_size,
- int *ovcs_id);
+ int *ovcs_id, struct device_node *target_base);
int of_overlay_remove(int *ovcs_id);
int of_overlay_remove_all(void);
--
2.34.1