PCI: Add addon_resource support for pci_dev

Will add addon_resources list in pci_dev, it will be used for resources
other than standard, rom, sriov, bridges.
Some could be same as std reg, but using different register.
Some could have own way to read/write to them.

Kernel using different way to hack those resources like abusing
pci bridge resource spot on non bridge pci device.

With this patch, will treat addon-resource like standard resource with
special ops.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>

2 files changed, 56 insertions, 2 deletions

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 4f7fb8a60f1da6..5bae8c636cf398 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -107,22 +107,53 @@ postcore_initcall(pcibus_class_init);
 
 struct resource *pci_dev_resource_n(struct pci_dev *dev, int n)
 {
-	if (n >= 0 && n < PCI_NUM_RESOURCES)
+	struct pci_dev_addon_resource *addon_res;
+
+	if (n < 0)
+		return NULL;
+
+	if (n < PCI_NUM_RESOURCES)
 		return &dev->resource[n];
 
+	n -= PCI_NUM_RESOURCES;
+	list_for_each_entry(addon_res, &dev->addon_resources, list) {
+		if (n-- == 0)
+			return &addon_res->res;
+	}
+
 	return NULL;
 }
 EXPORT_SYMBOL(pci_dev_resource_n);
 
 int pci_dev_resource_idx(struct pci_dev *dev, struct resource *res)
 {
+	struct pci_dev_addon_resource *addon_res;
+	int n;
+
 	if (res >= dev->resource &&
 	    res <= dev->resource + (PCI_NUM_RESOURCES - 1))
 		return res - dev->resource;
 
+	n = PCI_NUM_RESOURCES;
+	list_for_each_entry(addon_res, &dev->addon_resources, list) {
+		if (res == &addon_res->res)
+			return n;
+		n++;
+	}
+
 	return -1;
 }
 
+static void pci_release_dev_addon_res(struct pci_dev *dev)
+{
+	struct pci_dev_addon_resource *addon_res, *tmp;
+
+	list_for_each_entry_safe(addon_res, tmp, &dev->addon_resources, list) {
+		list_del(&addon_res->list);
+		kfree(addon_res);
+	}
+}
+
 static void __init_res_idx_mask(unsigned long *mask, int flag)
 {
 	bitmap_zero(mask, PCI_NUM_RESOURCES);
@@ -167,6 +198,9 @@ int pci_next_resource_idx(int i, int flag)
 	if (i < PCI_NUM_RESOURCES)
 		return i;
 
+	if (flag & PCI_ADDON_RES)
+		return i;
+
 	return -1;
 }
 
@@ -1182,6 +1216,7 @@ static void pci_release_dev(struct device *dev)
 	pci_dev = to_pci_dev(dev);
 	pci_release_capabilities(pci_dev);
 	pci_release_of_node(pci_dev);
+	pci_release_dev_addon_res(pci_dev);
 	kfree(pci_dev);
 }
 
@@ -1259,6 +1294,7 @@ struct pci_dev *alloc_pci_dev(void)
 		return NULL;
 
 	INIT_LIST_HEAD(&dev->bus_list);
+	INIT_LIST_HEAD(&dev->addon_resources);
 
 	return dev;
 }
diff --git a/include/linux/pci.h b/include/linux/pci.h
index d88b4d38e7f9fc..1940849ff7ccab 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -330,6 +330,7 @@ struct pci_dev {
 	 */
 	unsigned int	irq;
 	struct resource resource[DEVICE_COUNT_RESOURCE]; /* I/O and memory regions + expansion ROMs */
+	struct list_head addon_resources; /* addon I/O and memory resource */
 
 	/* These fields are used by common fixups */
 	unsigned int	transparent:1;	/* Transparent PCI bridge */
@@ -380,6 +381,21 @@ struct pci_dev {
 #endif
 };
 
+struct resource_ops {
+	int (*read)(struct pci_dev *dev, struct resource *res, int addr);
+	int (*write)(struct pci_dev *dev, struct resource *res, int addr);
+};
+
+struct pci_dev_addon_resource {
+	struct list_head list;
+	int reg_addr;
+	int size;
+	struct resource res;
+	struct resource_ops *ops;
+};
+#define	to_pci_dev_addon_resource(n)					\
+	container_of(n, struct pci_dev_addon_resource, res)
+
 struct resource *pci_dev_resource_n(struct pci_dev *dev, int n);
 int pci_dev_resource_idx(struct pci_dev *dev, struct resource *res);
 
@@ -388,8 +404,10 @@ int pci_dev_resource_idx(struct pci_dev *dev, struct resource *res);
 #define PCI_IOV_RES		(1<<2)
 #define PCI_BRIDGE_RES		(1<<3)
 #define PCI_RES_BLOCK_NUM	4
+/* addon does not need use bitmap ...*/
+#define PCI_ADDON_RES		(1<<4)
 
-#define PCI_ALL_RES		(PCI_STD_RES | PCI_ROM_RES | PCI_BRIDGE_RES | PCI_IOV_RES)
+#define PCI_ALL_RES		(PCI_STD_RES | PCI_ROM_RES | PCI_BRIDGE_RES | PCI_IOV_RES | PCI_ADDON_RES)
 #define PCI_NOSTD_RES		(PCI_ALL_RES & ~PCI_STD_RES)
 #define PCI_NOIOV_RES		(PCI_ALL_RES & ~PCI_IOV_RES)
 #define PCI_NOROM_RES		(PCI_ALL_RES & ~PCI_ROM_RES)