@@ -193,6 +193,18 @@ config PCI_HYPERV
The PCI device frontend driver allows the kernel to import arbitrary
PCI devices from a PCI backend to support PCI driver domains.
+config PCI_DYNAMIC_OF_NODES
+ bool "Create Devicetree nodes for PCI devices"
+ depends on OF
+ select OF_DYNAMIC
+ help
+ This option enables support for generating device tree nodes for some
+ PCI devices. Thus, the driver of this kind can load and overlay
+ flattened device tree for its downstream devices.
+
+ Once this option is selected, the device tree nodes will be generated
+ for all PCI bridges.
+
choice
prompt "PCI Express hierarchy optimization setting"
default PCIE_BUS_DEFAULT
@@ -32,6 +32,7 @@ obj-$(CONFIG_PCI_P2PDMA) += p2pdma.o
obj-$(CONFIG_XEN_PCIDEV_FRONTEND) += xen-pcifront.o
obj-$(CONFIG_VGA_ARB) += vgaarb.o
obj-$(CONFIG_PCI_DOE) += doe.o
+obj-$(CONFIG_PCI_DYNAMIC_OF_NODES) += of_property.o
# Endpoint library must be initialized before its users
obj-$(CONFIG_PCI_ENDPOINT) += endpoint/
@@ -340,6 +340,8 @@ void pci_bus_add_device(struct pci_dev *dev)
*/
pcibios_bus_add_device(dev);
pci_fixup_device(pci_fixup_final, dev);
+ if (pci_is_bridge(dev))
+ of_pci_make_dev_node(dev);
pci_create_sysfs_dev_files(dev);
pci_proc_attach_device(dev);
pci_bridge_d3_update(dev);
@@ -501,8 +501,10 @@ static int of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args *
* to rely on this function (you ship a firmware that doesn't
* create device nodes for all PCI devices).
*/
- if (ppnode)
+ if (ppnode && of_property_present(ppnode, "interrupt-map"))
break;
+ else
+ ppnode = NULL;
/*
* We can only get here if we hit a P2P bridge with no node;
@@ -617,6 +619,83 @@ int devm_of_pci_bridge_init(struct device *dev, struct pci_host_bridge *bridge)
return pci_parse_request_of_pci_ranges(dev, bridge);
}
+#if IS_ENABLED(CONFIG_PCI_DYNAMIC_OF_NODES)
+
+void of_pci_remove_node(struct pci_dev *pdev)
+{
+ struct device_node *np;
+
+ np = pci_device_to_OF_node(pdev);
+ if (!np || !of_node_check_flag(np, OF_DYNAMIC))
+ return;
+ pdev->dev.of_node = NULL;
+
+ of_changeset_revert(np->data);
+ of_changeset_destroy(np->data);
+ of_node_put(np);
+}
+
+void of_pci_make_dev_node(struct pci_dev *pdev)
+{
+ struct device_node *ppnode, *np = NULL;
+ const char *pci_type = "dev";
+ struct of_changeset *cset;
+ const char *name;
+ int ret;
+
+ /*
+ * If there is already a device tree node linked to this device,
+ * return immediately.
+ */
+ if (pci_device_to_OF_node(pdev))
+ return;
+
+ /* Check if there is device tree node for parent device */
+ if (!pdev->bus->self)
+ ppnode = pdev->bus->dev.of_node;
+ else
+ ppnode = pdev->bus->self->dev.of_node;
+ if (!ppnode)
+ return;
+
+ if (pci_is_bridge(pdev))
+ pci_type = "pci";
+
+ name = kasprintf(GFP_KERNEL, "%s@%x,%x", pci_type,
+ PCI_SLOT(pdev->devfn), PCI_FUNC(pdev->devfn));
+ if (!name)
+ return;
+
+ cset = kmalloc(sizeof(*cset), GFP_KERNEL);
+ if (!cset)
+ goto failed;
+ of_changeset_init(cset);
+
+ np = of_changeset_create_node(ppnode, name, cset);
+ if (!np)
+ goto failed;
+ np->data = cset;
+
+ ret = of_pci_add_properties(pdev, cset, np);
+ if (ret)
+ goto failed;
+
+ ret = of_changeset_apply(cset);
+ if (ret)
+ goto failed;
+
+ pdev->dev.of_node = np;
+ kfree(name);
+
+ return;
+
+failed:
+ if (np)
+ of_node_put(np);
+ kfree(name);
+}
+#endif
+
#endif /* CONFIG_PCI */
/**
new file mode 100644
@@ -0,0 +1,179 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2022, Advanced Micro Devices, Inc.
+ */
+
+#include <linux/pci.h>
+#include <linux/of.h>
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include "pci.h"
+
+#define OF_PCI_ADDRESS_CELLS 3
+#define OF_PCI_SIZE_CELLS 2
+
+struct of_pci_addr_pair {
+ u32 phys_addr[OF_PCI_ADDRESS_CELLS];
+ u32 size[OF_PCI_SIZE_CELLS];
+};
+
+struct of_pci_range {
+ u32 child_addr[OF_PCI_ADDRESS_CELLS];
+ u32 parent_addr[OF_PCI_ADDRESS_CELLS];
+ u32 size[OF_PCI_SIZE_CELLS];
+};
+
+#define OF_PCI_ADDR_SPACE_IO 0x1
+#define OF_PCI_ADDR_SPACE_MEM32 0x2
+#define OF_PCI_ADDR_SPACE_MEM64 0x3
+
+#define OF_PCI_ADDR_FIELD_NONRELOC BIT(31)
+#define OF_PCI_ADDR_FIELD_SS GENMASK(25, 24)
+#define OF_PCI_ADDR_FIELD_PREFETCH BIT(30)
+#define OF_PCI_ADDR_FIELD_BUS GENMASK(23, 16)
+#define OF_PCI_ADDR_FIELD_DEV GENMASK(15, 11)
+#define OF_PCI_ADDR_FIELD_FUNC GENMASK(10, 8)
+#define OF_PCI_ADDR_FIELD_REG GENMASK(7, 0)
+
+enum of_pci_prop_compatible {
+ PROP_COMPAT_PCI_VVVV_DDDD,
+ PROP_COMPAT_PCICLASS_CCSSPP,
+ PROP_COMPAT_PCICLASS_CCSS,
+ PROP_COMPAT_NUM,
+};
+
+static void of_pci_set_address(struct pci_dev *pdev, u32 *prop, u64 addr,
+ u32 reg_num, u32 flags, bool reloc)
+{
+ prop[0] = FIELD_PREP(OF_PCI_ADDR_FIELD_BUS, pdev->bus->number) |
+ FIELD_PREP(OF_PCI_ADDR_FIELD_DEV, PCI_SLOT(pdev->devfn)) |
+ FIELD_PREP(OF_PCI_ADDR_FIELD_FUNC, PCI_FUNC(pdev->devfn));
+ prop[0] |= flags | reg_num;
+ if (!reloc) {
+ prop[0] |= OF_PCI_ADDR_FIELD_NONRELOC;
+ prop[1] = upper_32_bits(addr);
+ prop[2] = lower_32_bits(addr);
+ }
+}
+
+static int of_pci_get_addr_flags(struct resource *res, u32 *flags)
+{
+ u32 ss;
+
+ if (res->flags & IORESOURCE_IO)
+ ss = OF_PCI_ADDR_SPACE_IO;
+ else if (res->flags & IORESOURCE_MEM_64)
+ ss = OF_PCI_ADDR_SPACE_MEM64;
+ else if (res->flags & IORESOURCE_MEM)
+ ss = OF_PCI_ADDR_SPACE_MEM32;
+ else
+ return -EINVAL;
+
+ *flags = 0;
+ if (res->flags & IORESOURCE_PREFETCH)
+ *flags |= OF_PCI_ADDR_FIELD_PREFETCH;
+
+ *flags |= FIELD_PREP(OF_PCI_ADDR_FIELD_SS, ss);
+
+ return 0;
+}
+
+static int of_pci_prop_ranges(struct pci_dev *pdev, struct of_changeset *ocs,
+ struct device_node *np)
+{
+ struct of_pci_range *rp;
+ struct resource *res;
+ int i = 0, j, ret;
+ u64 val64;
+ u32 flags;
+
+ rp = kcalloc(PCI_BRIDGE_RESOURCE_NUM, sizeof(*rp), GFP_KERNEL);
+ if (!rp)
+ return -ENOMEM;
+
+ res = &pdev->resource[PCI_BRIDGE_RESOURCES];
+ for (j = 0; j < PCI_BRIDGE_RESOURCE_NUM; j++) {
+ if (!resource_size(&res[j]))
+ continue;
+
+ if (of_pci_get_addr_flags(&res[j], &flags))
+ continue;
+
+ val64 = res[j].start;
+ of_pci_set_address(pdev, rp[i].parent_addr, val64, 0, flags,
+ false);
+ memcpy(rp[i].child_addr, rp[i].parent_addr,
+ sizeof(rp[i].child_addr));
+
+ val64 = resource_size(&res[j]);
+ rp[i].size[0] = upper_32_bits(val64);
+ rp[i].size[1] = lower_32_bits(val64);
+
+ i++;
+ }
+
+ ret = of_changeset_add_prop_u32_array(ocs, np, "ranges", (u32 *)rp,
+ i * sizeof(*rp) / sizeof(u32));
+ kfree(rp);
+
+ return ret;
+}
+
+static int of_pci_prop_reg(struct pci_dev *pdev, struct of_changeset *ocs,
+ struct device_node *np)
+{
+ struct of_pci_addr_pair reg;
+
+ /* configuration space */
+ of_pci_set_address(pdev, reg.phys_addr, 0, 0, 0, true);
+
+ return of_changeset_add_prop_u32_array(ocs, np, "reg", (u32 *)®,
+ sizeof(reg) / sizeof(u32));
+}
+
+static int of_pci_prop_compatible(struct pci_dev *pdev,
+ struct of_changeset *ocs,
+ struct device_node *np)
+{
+ const char *compat_strs[PROP_COMPAT_NUM] = { 0 };
+ int i, ret;
+
+ compat_strs[PROP_COMPAT_PCI_VVVV_DDDD] =
+ kasprintf(GFP_KERNEL, "pci%x,%x", pdev->vendor, pdev->device);
+ compat_strs[PROP_COMPAT_PCICLASS_CCSSPP] =
+ kasprintf(GFP_KERNEL, "pciclass,%06x", pdev->class);
+ compat_strs[PROP_COMPAT_PCICLASS_CCSS] =
+ kasprintf(GFP_KERNEL, "pciclass,%04x", pdev->class >> 8);
+
+ ret = of_changeset_add_prop_string_array(ocs, np, "compatible",
+ compat_strs, PROP_COMPAT_NUM);
+ for (i = 0; i < PROP_COMPAT_NUM; i++)
+ kfree(compat_strs[i]);
+
+ return ret;
+}
+
+int of_pci_add_properties(struct pci_dev *pdev, struct of_changeset *ocs,
+ struct device_node *np)
+{
+ int ret = 0;
+
+ if (pci_is_bridge(pdev)) {
+ ret |= of_changeset_add_prop_string(ocs, np, "device_type",
+ "pci");
+ ret |= of_changeset_add_prop_u32(ocs, np, "#address-cells",
+ OF_PCI_ADDRESS_CELLS);
+ ret |= of_changeset_add_prop_u32(ocs, np, "#size-cells",
+ OF_PCI_SIZE_CELLS);
+ ret |= of_pci_prop_ranges(pdev, ocs, np);
+ }
+
+ ret |= of_pci_prop_reg(pdev, ocs, np);
+ ret |= of_pci_prop_compatible(pdev, ocs, np);
+
+ /*
+ * The added properties will be released when the
+ * changeset is destroyed.
+ */
+ return ret;
+}
@@ -678,6 +678,25 @@ static inline int devm_of_pci_bridge_init(struct device *dev, struct pci_host_br
#endif /* CONFIG_OF */
+struct of_changeset;
+
+#ifdef CONFIG_PCI_DYNAMIC_OF_NODES
+void of_pci_make_dev_node(struct pci_dev *pdev);
+void of_pci_remove_node(struct pci_dev *pdev);
+int of_pci_add_properties(struct pci_dev *pdev, struct of_changeset *ocs,
+ struct device_node *np);
+#else
+static inline void
+of_pci_make_dev_node(struct pci_dev *pdev)
+{
+}
+
+static inline void
+of_pci_remove_node(struct pci_dev *pdev)
+{
+}
+#endif /* CONFIG_PCI_DYNAMIC_OF_NODES */
+
#ifdef CONFIG_PCIEAER
void pci_no_aer(void);
void pci_aer_init(struct pci_dev *dev);
@@ -22,6 +22,7 @@ static void pci_stop_dev(struct pci_dev *dev)
device_release_driver(&dev->dev);
pci_proc_detach_device(dev);
pci_remove_sysfs_dev_files(dev);
+ of_pci_remove_node(dev);
pci_dev_assign_added(dev, false);
}