PCI: Use bridge window names (PCI_BRIDGE_IO_WINDOW etc)

Use bridge resource definitions instead of using the PCI_BRIDGE_RESOURCES
constant with an integer offeset.

Link: https://lore.kernel.org/r/20200520183411.1534621-2-kw@linux.com
Signed-off-by: Krzysztof Wilczynski <kw@linux.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/setup-bus.c

@@ -583,7 +583,7 @@ static void pci_setup_bridge_io(struct pci_dev *bridge)
 		io_mask = PCI_IO_1K_RANGE_MASK;
 
 	/* Set up the top and bottom of the PCI I/O segment for this bus */
-	res = &bridge->resource[PCI_BRIDGE_RESOURCES + 0];
+	res = &bridge->resource[PCI_BRIDGE_IO_WINDOW];
 	pcibios_resource_to_bus(bridge->bus, &region, res);
 	if (res->flags & IORESOURCE_IO) {
 		pci_read_config_word(bridge, PCI_IO_BASE, &l);
@@ -613,7 +613,7 @@ static void pci_setup_bridge_mmio(struct pci_dev *bridge)
 	u32 l;
 
 	/* Set up the top and bottom of the PCI Memory segment for this bus */
-	res = &bridge->resource[PCI_BRIDGE_RESOURCES + 1];
+	res = &bridge->resource[PCI_BRIDGE_MEM_WINDOW];
 	pcibios_resource_to_bus(bridge->bus, &region, res);
 	if (res->flags & IORESOURCE_MEM) {
 		l = (region.start >> 16) & 0xfff0;
@@ -640,7 +640,7 @@ static void pci_setup_bridge_mmio_pref(struct pci_dev *bridge)
 
 	/* Set up PREF base/limit */
 	bu = lu = 0;
-	res = &bridge->resource[PCI_BRIDGE_RESOURCES + 2];
+	res = &bridge->resource[PCI_BRIDGE_PREF_MEM_WINDOW];
 	pcibios_resource_to_bus(bridge->bus, &region, res);
 	if (res->flags & IORESOURCE_PREFETCH) {
 		l = (region.start >> 16) & 0xfff0;
@@ -707,14 +707,14 @@ int pci_claim_bridge_resource(struct pci_dev *bridge, int i)
 	if (!pci_bus_clip_resource(bridge, i))
 		return -EINVAL;	/* Clipping didn't change anything */
 
-	switch (i - PCI_BRIDGE_RESOURCES) {
-	case 0:
+	switch (i) {
+	case PCI_BRIDGE_IO_WINDOW:
 		pci_setup_bridge_io(bridge);
 		break;
-	case 1:
+	case PCI_BRIDGE_MEM_WINDOW:
 		pci_setup_bridge_mmio(bridge);
 		break;
-	case 2:
+	case PCI_BRIDGE_PREF_MEM_WINDOW:
 		pci_setup_bridge_mmio_pref(bridge);
 		break;
 	default:
@@ -735,18 +735,22 @@ int pci_claim_bridge_resource(struct pci_dev *bridge, int i)
 static void pci_bridge_check_ranges(struct pci_bus *bus)
 {
 	struct pci_dev *bridge = bus->self;
-	struct resource *b_res = &bridge->resource[PCI_BRIDGE_RESOURCES];
+	struct resource *b_res;
 
-	b_res[1].flags |= IORESOURCE_MEM;
+	b_res = &bridge->resource[PCI_BRIDGE_MEM_WINDOW];
+	b_res->flags |= IORESOURCE_MEM;
 
-	if (bridge->io_window)
-		b_res[0].flags |= IORESOURCE_IO;
+	if (bridge->io_window) {
+		b_res = &bridge->resource[PCI_BRIDGE_IO_WINDOW];
+		b_res->flags |= IORESOURCE_IO;
+	}
 
 	if (bridge->pref_window) {
-		b_res[2].flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH;
+		b_res = &bridge->resource[PCI_BRIDGE_PREF_MEM_WINDOW];
+		b_res->flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH;
 		if (bridge->pref_64_window) {
-			b_res[2].flags |= IORESOURCE_MEM_64;
-			b_res[2].flags |= PCI_PREF_RANGE_TYPE_64;
+			b_res->flags |= IORESOURCE_MEM_64 |
+					PCI_PREF_RANGE_TYPE_64;
 		}
 	}
 }
@@ -1105,35 +1109,37 @@ static void pci_bus_size_cardbus(struct pci_bus *bus,
 				 struct list_head *realloc_head)
 {
 	struct pci_dev *bridge = bus->self;
-	struct resource *b_res = &bridge->resource[PCI_BRIDGE_RESOURCES];
+	struct resource *b_res;
 	resource_size_t b_res_3_size = pci_cardbus_mem_size * 2;
 	u16 ctrl;
 
-	if (b_res[0].parent)
+	b_res = &bridge->resource[PCI_CB_BRIDGE_IO_0_WINDOW];
+	if (b_res->parent)
 		goto handle_b_res_1;
 	/*
 	 * Reserve some resources for CardBus.  We reserve a fixed amount
 	 * of bus space for CardBus bridges.
 	 */
-	b_res[0].start = pci_cardbus_io_size;
-	b_res[0].end = b_res[0].start + pci_cardbus_io_size - 1;
-	b_res[0].flags |= IORESOURCE_IO | IORESOURCE_STARTALIGN;
+	b_res->start = pci_cardbus_io_size;
+	b_res->end = b_res->start + pci_cardbus_io_size - 1;
+	b_res->flags |= IORESOURCE_IO | IORESOURCE_STARTALIGN;
 	if (realloc_head) {
-		b_res[0].end -= pci_cardbus_io_size;
+		b_res->end -= pci_cardbus_io_size;
 		add_to_list(realloc_head, bridge, b_res, pci_cardbus_io_size,
-				pci_cardbus_io_size);
+			    pci_cardbus_io_size);
 	}
 
 handle_b_res_1:
-	if (b_res[1].parent)
+	b_res = &bridge->resource[PCI_CB_BRIDGE_IO_1_WINDOW];
+	if (b_res->parent)
 		goto handle_b_res_2;
-	b_res[1].start = pci_cardbus_io_size;
-	b_res[1].end = b_res[1].start + pci_cardbus_io_size - 1;
-	b_res[1].flags |= IORESOURCE_IO | IORESOURCE_STARTALIGN;
+	b_res->start = pci_cardbus_io_size;
+	b_res->end = b_res->start + pci_cardbus_io_size - 1;
+	b_res->flags |= IORESOURCE_IO | IORESOURCE_STARTALIGN;
 	if (realloc_head) {
-		b_res[1].end -= pci_cardbus_io_size;
-		add_to_list(realloc_head, bridge, b_res+1, pci_cardbus_io_size,
-				 pci_cardbus_io_size);
+		b_res->end -= pci_cardbus_io_size;
+		add_to_list(realloc_head, bridge, b_res, pci_cardbus_io_size,
+			    pci_cardbus_io_size);
 	}
 
 handle_b_res_2:
@@ -1153,21 +1159,22 @@ handle_b_res_2:
 		pci_read_config_word(bridge, PCI_CB_BRIDGE_CONTROL, &ctrl);
 	}
 
-	if (b_res[2].parent)
+	b_res = &bridge->resource[PCI_CB_BRIDGE_MEM_0_WINDOW];
+	if (b_res->parent)
 		goto handle_b_res_3;
 	/*
 	 * If we have prefetchable memory support, allocate two regions.
 	 * Otherwise, allocate one region of twice the size.
 	 */
 	if (ctrl & PCI_CB_BRIDGE_CTL_PREFETCH_MEM0) {
-		b_res[2].start = pci_cardbus_mem_size;
-		b_res[2].end = b_res[2].start + pci_cardbus_mem_size - 1;
-		b_res[2].flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH |
-				  IORESOURCE_STARTALIGN;
+		b_res->start = pci_cardbus_mem_size;
+		b_res->end = b_res->start + pci_cardbus_mem_size - 1;
+		b_res->flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH |
+				    IORESOURCE_STARTALIGN;
 		if (realloc_head) {
-			b_res[2].end -= pci_cardbus_mem_size;
-			add_to_list(realloc_head, bridge, b_res+2,
-				 pci_cardbus_mem_size, pci_cardbus_mem_size);
+			b_res->end -= pci_cardbus_mem_size;
+			add_to_list(realloc_head, bridge, b_res,
+				    pci_cardbus_mem_size, pci_cardbus_mem_size);
 		}
 
 		/* Reduce that to half */
@@ -1175,15 +1182,16 @@ handle_b_res_2:
 	}
 
 handle_b_res_3:
-	if (b_res[3].parent)
+	b_res = &bridge->resource[PCI_CB_BRIDGE_MEM_1_WINDOW];
+	if (b_res->parent)
 		goto handle_done;
-	b_res[3].start = pci_cardbus_mem_size;
-	b_res[3].end = b_res[3].start + b_res_3_size - 1;
-	b_res[3].flags |= IORESOURCE_MEM | IORESOURCE_STARTALIGN;
+	b_res->start = pci_cardbus_mem_size;
+	b_res->end = b_res->start + b_res_3_size - 1;
+	b_res->flags |= IORESOURCE_MEM | IORESOURCE_STARTALIGN;
 	if (realloc_head) {
-		b_res[3].end -= b_res_3_size;
-		add_to_list(realloc_head, bridge, b_res+3, b_res_3_size,
-				 pci_cardbus_mem_size);
+		b_res->end -= b_res_3_size;
+		add_to_list(realloc_head, bridge, b_res, b_res_3_size,
+			    pci_cardbus_mem_size);
 	}
 
 handle_done:
@@ -1227,7 +1235,7 @@ void __pci_bus_size_bridges(struct pci_bus *bus, struct list_head *realloc_head)
 				break;
 		hdr_type = -1;	/* Intentionally invalid - not a PCI device. */
 	} else {
-		pref = &bus->self->resource[PCI_BRIDGE_RESOURCES + 2];
+		pref = &bus->self->resource[PCI_BRIDGE_PREF_MEM_WINDOW];
 		hdr_type = bus->self->hdr_type;
 	}
 
@@ -1885,9 +1893,9 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus,
 	struct pci_dev *dev, *bridge = bus->self;
 	resource_size_t io_per_hp, mmio_per_hp, mmio_pref_per_hp, align;
 
-	io_res = &bridge->resource[PCI_BRIDGE_RESOURCES + 0];
-	mmio_res = &bridge->resource[PCI_BRIDGE_RESOURCES + 1];
-	mmio_pref_res = &bridge->resource[PCI_BRIDGE_RESOURCES + 2];
+	io_res = &bridge->resource[PCI_BRIDGE_IO_WINDOW];
+	mmio_res = &bridge->resource[PCI_BRIDGE_MEM_WINDOW];
+	mmio_pref_res = &bridge->resource[PCI_BRIDGE_PREF_MEM_WINDOW];
 
 	/*
 	 * The alignment of this bridge is yet to be considered, hence it must
@@ -1960,21 +1968,21 @@ static void pci_bus_distribute_available_resources(struct pci_bus *bus,
 		 * Reduce the available resource space by what the
 		 * bridge and devices below it occupy.
 		 */
-		res = &dev->resource[PCI_BRIDGE_RESOURCES + 0];
+		res = &dev->resource[PCI_BRIDGE_IO_WINDOW];
 		align = pci_resource_alignment(dev, res);
 		align = align ? ALIGN(io.start, align) - io.start : 0;
 		used_size = align + resource_size(res);
 		if (!res->parent)
 			io.start = min(io.start + used_size, io.end + 1);
 
-		res = &dev->resource[PCI_BRIDGE_RESOURCES + 1];
+		res = &dev->resource[PCI_BRIDGE_MEM_WINDOW];
 		align = pci_resource_alignment(dev, res);
 		align = align ? ALIGN(mmio.start, align) - mmio.start : 0;
 		used_size = align + resource_size(res);
 		if (!res->parent)
 			mmio.start = min(mmio.start + used_size, mmio.end + 1);
 
-		res = &dev->resource[PCI_BRIDGE_RESOURCES + 2];
+		res = &dev->resource[PCI_BRIDGE_PREF_MEM_WINDOW];
 		align = pci_resource_alignment(dev, res);
 		align = align ? ALIGN(mmio_pref.start, align) -
 			mmio_pref.start : 0;
@@ -2027,9 +2035,9 @@ static void pci_bridge_distribute_available_resources(struct pci_dev *bridge,
 		return;
 
 	/* Take the initial extra resources from the hotplug port */
-	available_io = bridge->resource[PCI_BRIDGE_RESOURCES + 0];
-	available_mmio = bridge->resource[PCI_BRIDGE_RESOURCES + 1];
-	available_mmio_pref = bridge->resource[PCI_BRIDGE_RESOURCES + 2];
+	available_io = bridge->resource[PCI_BRIDGE_IO_WINDOW];
+	available_mmio = bridge->resource[PCI_BRIDGE_MEM_WINDOW];
+	available_mmio_pref = bridge->resource[PCI_BRIDGE_PREF_MEM_WINDOW];
 
 	pci_bus_distribute_available_resources(bridge->subordinate,
 					       add_list, available_io,

drivers/pcmcia/yenta_socket.c

@@ -694,7 +694,7 @@ static int yenta_allocate_res(struct yenta_socket *socket, int nr, unsigned type
 	struct pci_bus_region region;
 	unsigned mask;
 
-	res = dev->resource + PCI_BRIDGE_RESOURCES + nr;
+	res = &dev->resource[nr];
 	/* Already allocated? */
 	if (res->parent)
 		return 0;
@@ -711,7 +711,7 @@ static int yenta_allocate_res(struct yenta_socket *socket, int nr, unsigned type
 	region.end = config_readl(socket, addr_end) | ~mask;
 	if (region.start && region.end > region.start && !override_bios) {
 		pcibios_bus_to_resource(dev->bus, res, &region);
-		if (pci_claim_resource(dev, PCI_BRIDGE_RESOURCES + nr) == 0)
+		if (pci_claim_resource(dev, nr) == 0)
 			return 0;
 		dev_info(&dev->dev,
 			 "Preassigned resource %d busy or not available, reconfiguring...\n",
@@ -751,13 +751,17 @@ static int yenta_allocate_res(struct yenta_socket *socket, int nr, unsigned type
 static void yenta_allocate_resources(struct yenta_socket *socket)
 {
 	int program = 0;
-	program += yenta_allocate_res(socket, 0, IORESOURCE_IO,
+	program += yenta_allocate_res(socket, PCI_CB_BRIDGE_IO_0_WINDOW,
+			   IORESOURCE_IO,
 			   PCI_CB_IO_BASE_0, PCI_CB_IO_LIMIT_0);
-	program += yenta_allocate_res(socket, 1, IORESOURCE_IO,
+	program += yenta_allocate_res(socket, PCI_CB_BRIDGE_IO_1_WINDOW,
+			   IORESOURCE_IO,
 			   PCI_CB_IO_BASE_1, PCI_CB_IO_LIMIT_1);
-	program += yenta_allocate_res(socket, 2, IORESOURCE_MEM|IORESOURCE_PREFETCH,
+	program += yenta_allocate_res(socket, PCI_CB_BRIDGE_MEM_0_WINDOW,
+			   IORESOURCE_MEM | IORESOURCE_PREFETCH,
 			   PCI_CB_MEMORY_BASE_0, PCI_CB_MEMORY_LIMIT_0);
-	program += yenta_allocate_res(socket, 3, IORESOURCE_MEM,
+	program += yenta_allocate_res(socket, PCI_CB_BRIDGE_MEM_1_WINDOW,
+			   IORESOURCE_MEM,
 			   PCI_CB_MEMORY_BASE_1, PCI_CB_MEMORY_LIMIT_1);
 	if (program)
 		pci_setup_cardbus(socket->dev->subordinate);

include/linux/pci.h

@@ -100,9 +100,21 @@ enum {
 	PCI_IOV_RESOURCE_END = PCI_IOV_RESOURCES + PCI_SRIOV_NUM_BARS - 1,
 #endif
 
-	/* Resources assigned to buses behind the bridge */
+/* PCI-to-PCI (P2P) bridge windows */
+#define PCI_BRIDGE_IO_WINDOW		(PCI_BRIDGE_RESOURCES + 0)
+#define PCI_BRIDGE_MEM_WINDOW		(PCI_BRIDGE_RESOURCES + 1)
+#define PCI_BRIDGE_PREF_MEM_WINDOW	(PCI_BRIDGE_RESOURCES + 2)
+
+/* CardBus bridge windows */
+#define PCI_CB_BRIDGE_IO_0_WINDOW	(PCI_BRIDGE_RESOURCES + 0)
+#define PCI_CB_BRIDGE_IO_1_WINDOW	(PCI_BRIDGE_RESOURCES + 1)
+#define PCI_CB_BRIDGE_MEM_0_WINDOW	(PCI_BRIDGE_RESOURCES + 2)
+#define PCI_CB_BRIDGE_MEM_1_WINDOW	(PCI_BRIDGE_RESOURCES + 3)
+
+/* Total number of bridge resources for P2P and CardBus */
 #define PCI_BRIDGE_RESOURCE_NUM 4
 
+	/* Resources assigned to buses behind the bridge */
 	PCI_BRIDGE_RESOURCES,
 	PCI_BRIDGE_RESOURCE_END = PCI_BRIDGE_RESOURCES +
 				  PCI_BRIDGE_RESOURCE_NUM - 1,