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-rw-r--r--arch/loongarch/pci/acpi.c243
1 files changed, 243 insertions, 0 deletions
diff --git a/arch/loongarch/pci/acpi.c b/arch/loongarch/pci/acpi.c
new file mode 100644
index 000000000..8235ec92b
--- /dev/null
+++ b/arch/loongarch/pci/acpi.c
@@ -0,0 +1,243 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#include <linux/pci.h>
+#include <linux/acpi.h>
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/slab.h>
+#include <linux/pci-acpi.h>
+#include <linux/pci-ecam.h>
+
+#include <asm/pci.h>
+#include <asm/numa.h>
+#include <asm/loongson.h>
+
+struct pci_root_info {
+ struct acpi_pci_root_info common;
+ struct pci_config_window *cfg;
+};
+
+void pcibios_add_bus(struct pci_bus *bus)
+{
+ acpi_pci_add_bus(bus);
+}
+
+int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
+{
+ struct pci_config_window *cfg = bridge->bus->sysdata;
+ struct acpi_device *adev = to_acpi_device(cfg->parent);
+ struct device *bus_dev = &bridge->bus->dev;
+
+ ACPI_COMPANION_SET(&bridge->dev, adev);
+ set_dev_node(bus_dev, pa_to_nid(cfg->res.start));
+
+ return 0;
+}
+
+int acpi_pci_bus_find_domain_nr(struct pci_bus *bus)
+{
+ struct pci_config_window *cfg = bus->sysdata;
+ struct acpi_device *adev = to_acpi_device(cfg->parent);
+ struct acpi_pci_root *root = acpi_driver_data(adev);
+
+ return root->segment;
+}
+
+static void acpi_release_root_info(struct acpi_pci_root_info *ci)
+{
+ struct pci_root_info *info;
+
+ info = container_of(ci, struct pci_root_info, common);
+ pci_ecam_free(info->cfg);
+ kfree(ci->ops);
+ kfree(info);
+}
+
+static int acpi_prepare_root_resources(struct acpi_pci_root_info *ci)
+{
+ int status;
+ struct resource_entry *entry, *tmp;
+ struct acpi_device *device = ci->bridge;
+
+ status = acpi_pci_probe_root_resources(ci);
+ if (status > 0) {
+ resource_list_for_each_entry_safe(entry, tmp, &ci->resources) {
+ if (entry->res->flags & IORESOURCE_MEM) {
+ entry->offset = ci->root->mcfg_addr & GENMASK_ULL(63, 40);
+ entry->res->start |= entry->offset;
+ entry->res->end |= entry->offset;
+ }
+ }
+ return status;
+ }
+
+ resource_list_for_each_entry_safe(entry, tmp, &ci->resources) {
+ dev_dbg(&device->dev,
+ "host bridge window %pR (ignored)\n", entry->res);
+ resource_list_destroy_entry(entry);
+ }
+
+ return 0;
+}
+
+/*
+ * Create a PCI config space window
+ * - reserve mem region
+ * - alloc struct pci_config_window with space for all mappings
+ * - ioremap the config space
+ */
+static struct pci_config_window *arch_pci_ecam_create(struct device *dev,
+ struct resource *cfgres, struct resource *busr, const struct pci_ecam_ops *ops)
+{
+ int bsz, bus_range, err;
+ struct resource *conflict;
+ struct pci_config_window *cfg;
+
+ if (busr->start > busr->end)
+ return ERR_PTR(-EINVAL);
+
+ cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
+ if (!cfg)
+ return ERR_PTR(-ENOMEM);
+
+ cfg->parent = dev;
+ cfg->ops = ops;
+ cfg->busr.start = busr->start;
+ cfg->busr.end = busr->end;
+ cfg->busr.flags = IORESOURCE_BUS;
+ bus_range = resource_size(cfgres) >> ops->bus_shift;
+
+ bsz = 1 << ops->bus_shift;
+
+ cfg->res.start = cfgres->start;
+ cfg->res.end = cfgres->end;
+ cfg->res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+ cfg->res.name = "PCI ECAM";
+
+ conflict = request_resource_conflict(&iomem_resource, &cfg->res);
+ if (conflict) {
+ err = -EBUSY;
+ dev_err(dev, "can't claim ECAM area %pR: address conflict with %s %pR\n",
+ &cfg->res, conflict->name, conflict);
+ goto err_exit;
+ }
+
+ cfg->win = pci_remap_cfgspace(cfgres->start, bus_range * bsz);
+ if (!cfg->win)
+ goto err_exit_iomap;
+
+ if (ops->init) {
+ err = ops->init(cfg);
+ if (err)
+ goto err_exit;
+ }
+ dev_info(dev, "ECAM at %pR for %pR\n", &cfg->res, &cfg->busr);
+
+ return cfg;
+
+err_exit_iomap:
+ err = -ENOMEM;
+ dev_err(dev, "ECAM ioremap failed\n");
+err_exit:
+ pci_ecam_free(cfg);
+ return ERR_PTR(err);
+}
+
+/*
+ * Lookup the bus range for the domain in MCFG, and set up config space
+ * mapping.
+ */
+static struct pci_config_window *
+pci_acpi_setup_ecam_mapping(struct acpi_pci_root *root)
+{
+ int ret, bus_shift;
+ u16 seg = root->segment;
+ struct device *dev = &root->device->dev;
+ struct resource cfgres;
+ struct resource *bus_res = &root->secondary;
+ struct pci_config_window *cfg;
+ const struct pci_ecam_ops *ecam_ops;
+
+ ret = pci_mcfg_lookup(root, &cfgres, &ecam_ops);
+ if (ret < 0) {
+ dev_err(dev, "%04x:%pR ECAM region not found, use default value\n", seg, bus_res);
+ ecam_ops = &loongson_pci_ecam_ops;
+ root->mcfg_addr = mcfg_addr_init(0);
+ }
+
+ bus_shift = ecam_ops->bus_shift ? : 20;
+
+ if (bus_shift == 20)
+ cfg = pci_ecam_create(dev, &cfgres, bus_res, ecam_ops);
+ else {
+ cfgres.start = root->mcfg_addr + (bus_res->start << bus_shift);
+ cfgres.end = cfgres.start + (resource_size(bus_res) << bus_shift) - 1;
+ cfgres.end |= BIT(28) + (((PCI_CFG_SPACE_EXP_SIZE - 1) & 0xf00) << 16);
+ cfgres.flags = IORESOURCE_MEM;
+ cfg = arch_pci_ecam_create(dev, &cfgres, bus_res, ecam_ops);
+ }
+
+ if (IS_ERR(cfg)) {
+ dev_err(dev, "%04x:%pR error %ld mapping ECAM\n", seg, bus_res, PTR_ERR(cfg));
+ return NULL;
+ }
+
+ return cfg;
+}
+
+struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
+{
+ struct pci_bus *bus;
+ struct pci_root_info *info;
+ struct acpi_pci_root_ops *root_ops;
+ int domain = root->segment;
+ int busnum = root->secondary.start;
+
+ info = kzalloc(sizeof(*info), GFP_KERNEL);
+ if (!info) {
+ pr_warn("pci_bus %04x:%02x: ignored (out of memory)\n", domain, busnum);
+ return NULL;
+ }
+
+ root_ops = kzalloc(sizeof(*root_ops), GFP_KERNEL);
+ if (!root_ops) {
+ kfree(info);
+ return NULL;
+ }
+
+ info->cfg = pci_acpi_setup_ecam_mapping(root);
+ if (!info->cfg) {
+ kfree(info);
+ kfree(root_ops);
+ return NULL;
+ }
+
+ root_ops->release_info = acpi_release_root_info;
+ root_ops->prepare_resources = acpi_prepare_root_resources;
+ root_ops->pci_ops = (struct pci_ops *)&info->cfg->ops->pci_ops;
+
+ bus = pci_find_bus(domain, busnum);
+ if (bus) {
+ memcpy(bus->sysdata, info->cfg, sizeof(struct pci_config_window));
+ kfree(info);
+ } else {
+ struct pci_bus *child;
+
+ bus = acpi_pci_root_create(root, root_ops,
+ &info->common, info->cfg);
+ if (!bus) {
+ kfree(info);
+ kfree(root_ops);
+ return NULL;
+ }
+
+ pci_bus_size_bridges(bus);
+ pci_bus_assign_resources(bus);
+ list_for_each_entry(child, &bus->children, node)
+ pcie_bus_configure_settings(child);
+ }
+
+ return bus;
+}