diff --git a/drivers/pci/ecam.c b/drivers/pci/ecam.c
index d2a1920bb0557..1c40d2506aef3 100644
--- a/drivers/pci/ecam.c
+++ b/drivers/pci/ecam.c
@@ -32,7 +32,7 @@ struct pci_config_window *pci_ecam_create(struct device *dev,
 	struct pci_config_window *cfg;
 	unsigned int bus_range, bus_range_max, bsz;
 	struct resource *conflict;
-	int i, err;
+	int err;
 
 	if (busr->start > busr->end)
 		return ERR_PTR(-EINVAL);
@@ -50,6 +50,7 @@ struct pci_config_window *pci_ecam_create(struct device *dev,
 	cfg->busr.start = busr->start;
 	cfg->busr.end = busr->end;
 	cfg->busr.flags = IORESOURCE_BUS;
+	cfg->bus_shift = bus_shift;
 	bus_range = resource_size(&cfg->busr);
 	bus_range_max = resource_size(cfgres) >> bus_shift;
 	if (bus_range > bus_range_max) {
@@ -77,13 +78,6 @@ struct pci_config_window *pci_ecam_create(struct device *dev,
 		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)
@@ -129,6 +123,44 @@ void pci_ecam_free(struct pci_config_window *cfg)
 }
 EXPORT_SYMBOL_GPL(pci_ecam_free);
 
+static int pci_ecam_add_bus(struct pci_bus *bus)
+{
+	struct pci_config_window *cfg = bus->sysdata;
+	unsigned int bsz = 1 << cfg->bus_shift;
+	unsigned int busn = bus->number;
+	phys_addr_t start;
+
+	if (!per_bus_mapping)
+		return 0;
+
+	if (busn < cfg->busr.start || busn > cfg->busr.end)
+		return -EINVAL;
+
+	busn -= cfg->busr.start;
+	start = cfg->res.start + busn * bsz;
+
+	cfg->winp[busn] = pci_remap_cfgspace(start, bsz);
+	if (!cfg->winp[busn])
+		return -ENOMEM;
+
+	return 0;
+}
+
+static void pci_ecam_remove_bus(struct pci_bus *bus)
+{
+	struct pci_config_window *cfg = bus->sysdata;
+	unsigned int busn = bus->number;
+
+	if (!per_bus_mapping || busn < cfg->busr.start || busn > cfg->busr.end)
+		return;
+
+	busn -= cfg->busr.start;
+	if (cfg->winp[busn]) {
+		iounmap(cfg->winp[busn]);
+		cfg->winp[busn] = NULL;
+	}
+}
+
 /*
  * Function to implement the pci_ops ->map_bus method
  */
@@ -167,6 +199,8 @@ EXPORT_SYMBOL_GPL(pci_ecam_map_bus);
 /* ECAM ops */
 const struct pci_ecam_ops pci_generic_ecam_ops = {
 	.pci_ops	= {
+		.add_bus	= pci_ecam_add_bus,
+		.remove_bus	= pci_ecam_remove_bus,
 		.map_bus	= pci_ecam_map_bus,
 		.read		= pci_generic_config_read,
 		.write		= pci_generic_config_write,
@@ -178,6 +212,8 @@ EXPORT_SYMBOL_GPL(pci_generic_ecam_ops);
 /* ECAM ops for 32-bit access only (non-compliant) */
 const struct pci_ecam_ops pci_32b_ops = {
 	.pci_ops	= {
+		.add_bus	= pci_ecam_add_bus,
+		.remove_bus	= pci_ecam_remove_bus,
 		.map_bus	= pci_ecam_map_bus,
 		.read		= pci_generic_config_read32,
 		.write		= pci_generic_config_write32,
@@ -187,6 +223,8 @@ const struct pci_ecam_ops pci_32b_ops = {
 /* ECAM ops for 32-bit read only (non-compliant) */
 const struct pci_ecam_ops pci_32b_read_ops = {
 	.pci_ops	= {
+		.add_bus	= pci_ecam_add_bus,
+		.remove_bus	= pci_ecam_remove_bus,
 		.map_bus	= pci_ecam_map_bus,
 		.read		= pci_generic_config_read32,
 		.write		= pci_generic_config_write,
diff --git a/include/linux/pci-ecam.h b/include/linux/pci-ecam.h
index fbdadd4d83774..adea5a4771cf8 100644
--- a/include/linux/pci-ecam.h
+++ b/include/linux/pci-ecam.h
@@ -55,6 +55,7 @@ struct pci_ecam_ops {
 struct pci_config_window {
 	struct resource			res;
 	struct resource			busr;
+	unsigned int			bus_shift;
 	void				*priv;
 	const struct pci_ecam_ops	*ops;
 	union {