| Message ID | 1665598440-47410-1-git-send-email-lizhi.hou@amd.com |
|---|---|
| Headers | show |
| Series | Generate device tree node for pci devices | expand |
Le 12/10/2022 à 20:13, Lizhi Hou a écrit : > of_create_node() creates device node and apply to base tree dynamically. > The parent device node and full name are required for creating the node. > And the caller can also provide a property array for the node. > > Inside this function, it creates a changeset. Then the new device node > and properties are added to the changeset and applied to base tree. The > pointer of this changeset is saved in device node private data. > > of_destroy_node() removes the node created by of_create_node() from the > base tree and free it. It gets the changeset pointer from device node > private data and call of_changeset_destroy() to free everything. > > Signed-off-by: Lizhi Hou <lizhi.hou@amd.com> > Signed-off-by: Sonal Santan <sonal.santan@amd.com> > Signed-off-by: Max Zhen <max.zhen@amd.com> > Signed-off-by: Brian Xu <brian.xu@amd.com> > --- > drivers/of/dynamic.c | 80 ++++++++++++++++++++++++++++++++++++++++++++ > include/linux/of.h | 4 +++ > 2 files changed, 84 insertions(+) > > diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c > index cd3821a6444f..eca28b723706 100644 > --- a/drivers/of/dynamic.c > +++ b/drivers/of/dynamic.c > @@ -934,3 +934,83 @@ int of_changeset_action(struct of_changeset *ocs, unsigned long action, > return 0; > } > EXPORT_SYMBOL_GPL(of_changeset_action); > + > +/** > + * of_create_node - Dynamically create a device node and apply it to base tree > + * > + * @parent: Pointer to parent device node > + * @full_name: Full name of device node > + * @props: Pointer to property array > + * > + * 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 property *props) > +{ > + struct of_changeset *cset; > + struct property *new_pp; > + struct device_node *np; > + int ret, i; > + > + cset = kzalloc(sizeof(*cset), GFP_KERNEL); Hi, kmalloc() would be enough. of_changeset_init() below already calls memset(). > + if (!cset) > + return NULL; > + > + of_changeset_init(cset); > + > + np = __of_node_dup(NULL, full_name); > + if (!np) > + goto failed; 'cset' seems to be leaking if __of_node_dup() fails. > + np->parent = parent; > + > + ret = of_changeset_attach_node(cset, np); > + if (ret) > + goto failed; > + > + if (props) { > + for (i = 0; props[i].name; i++) { > + new_pp = __of_prop_dup(&props[i], GFP_KERNEL); > + if (!new_pp) > + goto failed; > + ret = of_changeset_add_property(cset, np, new_pp); > + if (ret) { > + kfree(new_pp->name); > + kfree(new_pp->value); > + kfree(new_pp); > + goto failed; > + } > + } > + } > + > + ret = of_changeset_apply(cset); > + if (ret) > + goto failed; > + > + np->data = cset; > + > + return np; > + > +failed: > + of_changeset_destroy(cset); > + if (np) > + of_node_put(np); > + > + return NULL; > +} > + > +/** > + * 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 *cset; > + > + cset = (struct of_changeset *)np->data; > + of_changeset_destroy(cset); > + of_node_put(np); > + kfree(cset); > +} > diff --git a/include/linux/of.h b/include/linux/of.h > index 766d002bddb9..493ef957c1a8 100644 > --- a/include/linux/of.h > +++ b/include/linux/of.h > @@ -1475,6 +1475,10 @@ extern int of_changeset_revert(struct of_changeset *ocs); > extern int of_changeset_action(struct of_changeset *ocs, > unsigned long action, struct device_node *np, > struct property *prop); > +struct device_node *of_create_node(struct device_node *parent, > + const char *full_name, > + struct property *props); > +void of_destroy_node(struct device_node *np); > > static inline int of_changeset_attach_node(struct of_changeset *ocs, > struct device_node *np)
On 11/1/22 00:47, Christophe JAILLET wrote: > Le 12/10/2022 à 20:13, Lizhi Hou a écrit : >> of_create_node() creates device node and apply to base tree dynamically. >> The parent device node and full name are required for creating the node. >> And the caller can also provide a property array for the node. >> >> Inside this function, it creates a changeset. Then the new device node >> and properties are added to the changeset and applied to base tree. The >> pointer of this changeset is saved in device node private data. >> >> of_destroy_node() removes the node created by of_create_node() from the >> base tree and free it. It gets the changeset pointer from device node >> private data and call of_changeset_destroy() to free everything. >> >> Signed-off-by: Lizhi Hou <lizhi.hou@amd.com> >> Signed-off-by: Sonal Santan <sonal.santan@amd.com> >> Signed-off-by: Max Zhen <max.zhen@amd.com> >> Signed-off-by: Brian Xu <brian.xu@amd.com> >> --- >> drivers/of/dynamic.c | 80 ++++++++++++++++++++++++++++++++++++++++++++ >> include/linux/of.h | 4 +++ >> 2 files changed, 84 insertions(+) >> >> diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c >> index cd3821a6444f..eca28b723706 100644 >> --- a/drivers/of/dynamic.c >> +++ b/drivers/of/dynamic.c >> @@ -934,3 +934,83 @@ int of_changeset_action(struct of_changeset >> *ocs, unsigned long action, >> return 0; >> } >> EXPORT_SYMBOL_GPL(of_changeset_action); >> + >> +/** >> + * of_create_node - Dynamically create a device node and apply it to >> base tree >> + * >> + * @parent: Pointer to parent device node >> + * @full_name: Full name of device node >> + * @props: Pointer to property array >> + * >> + * 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 property *props) >> +{ >> + struct of_changeset *cset; >> + struct property *new_pp; >> + struct device_node *np; >> + int ret, i; >> + >> + cset = kzalloc(sizeof(*cset), GFP_KERNEL); > > Hi, > > kmalloc() would be enough. of_changeset_init() below already calls > memset(). Ok. > >> + if (!cset) >> + return NULL; >> + >> + of_changeset_init(cset); >> + >> + np = __of_node_dup(NULL, full_name); >> + if (!np) >> + goto failed; > > 'cset' seems to be leaking if __of_node_dup() fails. Will fix this. Thanks. Lizhi > >> + np->parent = parent; >> + >> + ret = of_changeset_attach_node(cset, np); >> + if (ret) >> + goto failed; >> + >> + if (props) { >> + for (i = 0; props[i].name; i++) { >> + new_pp = __of_prop_dup(&props[i], GFP_KERNEL); >> + if (!new_pp) >> + goto failed; >> + ret = of_changeset_add_property(cset, np, new_pp); >> + if (ret) { >> + kfree(new_pp->name); >> + kfree(new_pp->value); >> + kfree(new_pp); >> + goto failed; >> + } >> + } >> + } >> + >> + ret = of_changeset_apply(cset); >> + if (ret) >> + goto failed; >> + >> + np->data = cset; >> + >> + return np; >> + >> +failed: >> + of_changeset_destroy(cset); >> + if (np) >> + of_node_put(np); >> + >> + return NULL; >> +} >> + >> +/** >> + * 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 *cset; >> + >> + cset = (struct of_changeset *)np->data; >> + of_changeset_destroy(cset); >> + of_node_put(np); >> + kfree(cset); >> +} >> diff --git a/include/linux/of.h b/include/linux/of.h >> index 766d002bddb9..493ef957c1a8 100644 >> --- a/include/linux/of.h >> +++ b/include/linux/of.h >> @@ -1475,6 +1475,10 @@ extern int of_changeset_revert(struct >> of_changeset *ocs); >> extern int of_changeset_action(struct of_changeset *ocs, >> unsigned long action, struct device_node *np, >> struct property *prop); >> +struct device_node *of_create_node(struct device_node *parent, >> + const char *full_name, >> + struct property *props); >> +void of_destroy_node(struct device_node *np); >> static inline int of_changeset_attach_node(struct of_changeset *ocs, >> struct device_node *np) >
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/20220427094502.456111-1-clement.leger@bootlin.com/ 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/20220624034327.2542112-1-frowand.list@gmail.com/ https://lore.kernel.org/lkml/20220216050056.311496-1-lizhi.hou@xilinx.com/ 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 | |-- compatible | |-- device_type | `-- reg |-- pci@1,1 | |-- compatible | |-- device_type | `-- reg |-- pci@1,2 | |-- compatible | |-- device_type | `-- reg |-- pci@1,3 | |-- compatible | |-- device_type | `-- reg |-- pci@1,4 | |-- compatible | |-- device_type | `-- reg |-- pci@1,5 | |-- compatible | |-- device_type | `-- reg |-- pci@1,6 | |-- compatible | |-- device_type | `-- reg |-- pci@1,7 | |-- compatible | |-- device_type | `-- reg |-- pci@2,0 | |-- compatible | |-- device_type | |-- pci@0,0 | | |-- compatible | | |-- device_type | | |-- pci@0,0 | | | |-- compatible | | | |-- dev@0,0 | | | | |-- compatible | | | | `-- reg | | | |-- dev@0,1 | | | | |-- compatible | | | | `-- reg | | | |-- device_type | | | `-- reg | | `-- reg | `-- reg |-- pci@2,1 | |-- compatible | |-- device_type | `-- reg |-- pci@3,0 | |-- compatible | |-- device_type | |-- pci@0,0 | | |-- compatible | | |-- device_type | | `-- reg | `-- reg |-- ranges `-- reg 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 of_create_node() and of_destroy_node() PCI: Create device tree node for selected devices PCI: Add basic properties for dynamically generated PCI OF node drivers/of/dynamic.c | 80 ++++++++++++++++ drivers/pci/Kconfig | 12 +++ drivers/pci/Makefile | 1 + drivers/pci/bus.c | 2 + drivers/pci/msi/irqdomain.c | 6 +- drivers/pci/of.c | 69 ++++++++++++++ drivers/pci/of_property.c | 177 ++++++++++++++++++++++++++++++++++++ drivers/pci/pci-driver.c | 3 +- drivers/pci/pci.h | 17 ++++ drivers/pci/quirks.c | 11 +++ drivers/pci/remove.c | 1 + include/linux/of.h | 4 + 12 files changed, 380 insertions(+), 3 deletions(-) create mode 100644 drivers/pci/of_property.c