v4.19.13 snapshot.
diff --git a/drivers/pci/ecam.c b/drivers/pci/ecam.c
new file mode 100644
index 0000000..1a81af0
--- /dev/null
+++ b/drivers/pci/ecam.c
@@ -0,0 +1,167 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2016 Broadcom
+ */
+
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/pci-ecam.h>
+#include <linux/slab.h>
+
+/*
+ * On 64-bit systems, we do a single ioremap for the whole config space
+ * since we have enough virtual address range available. On 32-bit, we
+ * ioremap the config space for each bus individually.
+ */
+static const bool per_bus_mapping = !IS_ENABLED(CONFIG_64BIT);
+
+/*
+ * Create a PCI config space window
+ * - reserve mem region
+ * - alloc struct pci_config_window with space for all mappings
+ * - ioremap the config space
+ */
+struct pci_config_window *pci_ecam_create(struct device *dev,
+ struct resource *cfgres, struct resource *busr,
+ struct pci_ecam_ops *ops)
+{
+ struct pci_config_window *cfg;
+ unsigned int bus_range, bus_range_max, bsz;
+ struct resource *conflict;
+ int i, err;
+
+ 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(&cfg->busr);
+ bus_range_max = resource_size(cfgres) >> ops->bus_shift;
+ if (bus_range > bus_range_max) {
+ bus_range = bus_range_max;
+ cfg->busr.end = busr->start + bus_range - 1;
+ dev_warn(dev, "ECAM area %pR can only accommodate %pR (reduced from %pR desired)\n",
+ cfgres, &cfg->busr, busr);
+ }
+ 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;
+ }
+
+ if (per_bus_mapping) {
+ cfg->winp = kcalloc(bus_range, sizeof(*cfg->winp), GFP_KERNEL);
+ if (!cfg->winp)
+ goto err_exit_malloc;
+ for (i = 0; i < bus_range; i++) {
+ cfg->winp[i] =
+ pci_remap_cfgspace(cfgres->start + i * bsz,
+ bsz);
+ if (!cfg->winp[i])
+ goto err_exit_iomap;
+ }
+ } else {
+ 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:
+ dev_err(dev, "ECAM ioremap failed\n");
+err_exit_malloc:
+ err = -ENOMEM;
+err_exit:
+ pci_ecam_free(cfg);
+ return ERR_PTR(err);
+}
+
+void pci_ecam_free(struct pci_config_window *cfg)
+{
+ int i;
+
+ if (per_bus_mapping) {
+ if (cfg->winp) {
+ for (i = 0; i < resource_size(&cfg->busr); i++)
+ if (cfg->winp[i])
+ iounmap(cfg->winp[i]);
+ kfree(cfg->winp);
+ }
+ } else {
+ if (cfg->win)
+ iounmap(cfg->win);
+ }
+ if (cfg->res.parent)
+ release_resource(&cfg->res);
+ kfree(cfg);
+}
+
+/*
+ * Function to implement the pci_ops ->map_bus method
+ */
+void __iomem *pci_ecam_map_bus(struct pci_bus *bus, unsigned int devfn,
+ int where)
+{
+ struct pci_config_window *cfg = bus->sysdata;
+ unsigned int devfn_shift = cfg->ops->bus_shift - 8;
+ unsigned int busn = bus->number;
+ void __iomem *base;
+
+ if (busn < cfg->busr.start || busn > cfg->busr.end)
+ return NULL;
+
+ busn -= cfg->busr.start;
+ if (per_bus_mapping)
+ base = cfg->winp[busn];
+ else
+ base = cfg->win + (busn << cfg->ops->bus_shift);
+ return base + (devfn << devfn_shift) + where;
+}
+
+/* ECAM ops */
+struct pci_ecam_ops pci_generic_ecam_ops = {
+ .bus_shift = 20,
+ .pci_ops = {
+ .map_bus = pci_ecam_map_bus,
+ .read = pci_generic_config_read,
+ .write = pci_generic_config_write,
+ }
+};
+
+#if defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS)
+/* ECAM ops for 32-bit access only (non-compliant) */
+struct pci_ecam_ops pci_32b_ops = {
+ .bus_shift = 20,
+ .pci_ops = {
+ .map_bus = pci_ecam_map_bus,
+ .read = pci_generic_config_read32,
+ .write = pci_generic_config_write32,
+ }
+};
+#endif