PCI: Make pci_bus_for_each_resource() index optional

Refactor pci_bus_for_each_resource() in the same way as
pci_dev_for_each_resource(). This allows the index to be hidden inside the
implementation so the caller can omit it when it's not used otherwise.

No functional changes intended.

Link: https://lore.kernel.org/r/20230330162434.35055-6-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Krzysztof Wilczyński <kw@linux.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

drivers/pci/bus.c

@@ -161,13 +161,13 @@ static int pci_bus_alloc_from_region(struct pci_bus *bus, struct resource *res,
 		void *alignf_data,
 		struct pci_bus_region *region)
 {
-	int i, ret;
 	struct resource *r, avail;
 	resource_size_t max;
+	int ret;
 
 	type_mask |= IORESOURCE_TYPE_BITS;
 
-	pci_bus_for_each_resource(bus, r, i) {
+	pci_bus_for_each_resource(bus, r) {
 		resource_size_t min_used = min;
 
 		if (!r)
@@ -268,9 +268,8 @@ bool pci_bus_clip_resource(struct pci_dev *dev, int idx)
 	struct resource *res = &dev->resource[idx];
 	struct resource orig_res = *res;
 	struct resource *r;
-	int i;
 
-	pci_bus_for_each_resource(bus, r, i) {
+	pci_bus_for_each_resource(bus, r) {
 		resource_size_t start, end;
 
 		if (!r)

drivers/pci/hotplug/shpchp_sysfs.c

@@ -24,16 +24,16 @@
 static ssize_t show_ctrl(struct device *dev, struct device_attribute *attr, char *buf)
 {
 	struct pci_dev *pdev;
-	int index, busnr;
 	struct resource *res;
 	struct pci_bus *bus;
 	size_t len = 0;
+	int busnr;
 
 	pdev = to_pci_dev(dev);
 	bus = pdev->subordinate;
 
 	len += sysfs_emit_at(buf, len, "Free resources: memory\n");
-	pci_bus_for_each_resource(bus, res, index) {
+	pci_bus_for_each_resource(bus, res) {
 		if (res && (res->flags & IORESOURCE_MEM) &&
 				!(res->flags & IORESOURCE_PREFETCH)) {
 			len += sysfs_emit_at(buf, len,
@@ -43,7 +43,7 @@ static ssize_t show_ctrl(struct device *dev, struct device_attribute *attr, char
 		}
 	}
 	len += sysfs_emit_at(buf, len, "Free resources: prefetchable memory\n");
-	pci_bus_for_each_resource(bus, res, index) {
+	pci_bus_for_each_resource(bus, res) {
 		if (res && (res->flags & IORESOURCE_MEM) &&
 			       (res->flags & IORESOURCE_PREFETCH)) {
 			len += sysfs_emit_at(buf, len,
@@ -53,7 +53,7 @@ static ssize_t show_ctrl(struct device *dev, struct device_attribute *attr, char
 		}
 	}
 	len += sysfs_emit_at(buf, len, "Free resources: IO\n");
-	pci_bus_for_each_resource(bus, res, index) {
+	pci_bus_for_each_resource(bus, res) {
 		if (res && (res->flags & IORESOURCE_IO)) {
 			len += sysfs_emit_at(buf, len,
 					     "start = %8.8llx, length = %8.8llx\n",

drivers/pci/pci.c

@@ -779,9 +779,8 @@ struct resource *pci_find_parent_resource(const struct pci_dev *dev,
 {
 	const struct pci_bus *bus = dev->bus;
 	struct resource *r;
-	int i;
 
-	pci_bus_for_each_resource(bus, r, i) {
+	pci_bus_for_each_resource(bus, r) {
 		if (!r)
 			continue;
 		if (resource_contains(r, res)) {

drivers/pci/probe.c

@@ -533,7 +533,7 @@ void pci_read_bridge_bases(struct pci_bus *child)
 	pci_read_bridge_mmio_pref(child);
 
 	if (dev->transparent) {
-		pci_bus_for_each_resource(child->parent, res, i) {
+		pci_bus_for_each_resource(child->parent, res) {
 			if (res && res->flags) {
 				pci_bus_add_resource(child, res,
 						     PCI_SUBTRACTIVE_DECODE);

drivers/pci/setup-bus.c

@@ -770,9 +770,8 @@ static struct resource *find_bus_resource_of_type(struct pci_bus *bus,
 						  unsigned long type)
 {
 	struct resource *r, *r_assigned = NULL;
-	int i;
 
-	pci_bus_for_each_resource(bus, r, i) {
+	pci_bus_for_each_resource(bus, r) {
 		if (r == &ioport_resource || r == &iomem_resource)
 			continue;
 		if (r && (r->flags & type_mask) == type && !r->parent)
@@ -1204,7 +1203,7 @@ void __pci_bus_size_bridges(struct pci_bus *bus, struct list_head *realloc_head)
 			additional_mmio_pref_size = 0;
 	struct resource *pref;
 	struct pci_host_bridge *host;
-	int hdr_type, i, ret;
+	int hdr_type, ret;
 
 	list_for_each_entry(dev, &bus->devices, bus_list) {
 		struct pci_bus *b = dev->subordinate;
@@ -1228,7 +1227,7 @@ void __pci_bus_size_bridges(struct pci_bus *bus, struct list_head *realloc_head)
 		host = to_pci_host_bridge(bus->bridge);
 		if (!host->size_windows)
 			return;
-		pci_bus_for_each_resource(bus, pref, i)
+		pci_bus_for_each_resource(bus, pref)
 			if (pref && (pref->flags & IORESOURCE_PREFETCH))
 				break;
 		hdr_type = -1;	/* Intentionally invalid - not a PCI device. */
@@ -1333,12 +1332,11 @@ EXPORT_SYMBOL(pci_bus_size_bridges);
 
 static void assign_fixed_resource_on_bus(struct pci_bus *b, struct resource *r)
 {
-	int i;
 	struct resource *parent_r;
 	unsigned long mask = IORESOURCE_IO | IORESOURCE_MEM |
 			     IORESOURCE_PREFETCH;
 
-	pci_bus_for_each_resource(b, parent_r, i) {
+	pci_bus_for_each_resource(b, parent_r) {
 		if (!parent_r)
 			continue;
 

include/linux/pci.h

@@ -1444,11 +1444,21 @@ int devm_request_pci_bus_resources(struct device *dev,
 /* Temporary until new and working PCI SBR API in place */
 int pci_bridge_secondary_bus_reset(struct pci_dev *dev);
 
+#define __pci_bus_for_each_res0(bus, res, ...)				\
+	for (unsigned int __b = 0;					\
+	     (res = pci_bus_resource_n(bus, __b)) || __b < PCI_BRIDGE_RESOURCE_NUM; \
+	     __b++)
+
+#define __pci_bus_for_each_res1(bus, res, __b)				\
+	for (__b = 0;							\
+	     (res = pci_bus_resource_n(bus, __b)) || __b < PCI_BRIDGE_RESOURCE_NUM; \
+	     __b++)
+
 /**
  * pci_bus_for_each_resource - iterate over PCI bus resources
  * @bus: the PCI bus
  * @res: pointer to the current resource
- * @i: index of the current resource
+ * @...: optional index of the current resource
  *
  * Iterate over PCI bus resources. The first part is to go over PCI bus
  * resource array, which has at most the %PCI_BRIDGE_RESOURCE_NUM entries.
@@ -1461,13 +1471,17 @@ int pci_bridge_secondary_bus_reset(struct pci_dev *dev);
  *	struct resource *res;
  *	unsigned int i;
  *
+ * 	// With optional index
  * 	pci_bus_for_each_resource(bus, res, i)
  * 		pr_info("PCI bus resource[%u]: %pR\n", i, res);
+ *
+ * 	// Without index
+ * 	pci_bus_for_each_resource(bus, res)
+ * 		_do_something_(res);
  */
-#define pci_bus_for_each_resource(bus, res, i)				\
-	for (i = 0;							\
-	    (res = pci_bus_resource_n(bus, i)) || i < PCI_BRIDGE_RESOURCE_NUM; \
-	     i++)
+#define pci_bus_for_each_resource(bus, res, ...)			\
+	CONCATENATE(__pci_bus_for_each_res, COUNT_ARGS(__VA_ARGS__))	\
+		    (bus, res, __VA_ARGS__)
 
 int __must_check pci_bus_alloc_resource(struct pci_bus *bus,
 			struct resource *res, resource_size_t size,