1 files changed, 271 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/isa-bridge.c b/arch/powerpc/kernel/isa-bridge.c
new file mode 100644
index 00000000000..f0f49d1be3d
--- /dev/null
+++ b/arch/powerpc/kernel/isa-bridge.c
@@ -0,0 +1,271 @@
+/*
+ * Routines for tracking a legacy ISA bridge
+ *
+ * Copyrigh 2007 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp.
+ *
+ * Some bits and pieces moved over from pci_64.c
+ *
+ * Copyrigh 2003 Anton Blanchard <anton@au.ibm.com>, IBM Corp.
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+
+#define DEBUG
+
+#include <linux/kernel.h>
+#include <linux/pci.h>
+#include <linux/string.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/notifier.h>
+
+#include <asm/processor.h>
+#include <asm/io.h>
+#include <asm/prom.h>
+#include <asm/pci-bridge.h>
+#include <asm/machdep.h>
+#include <asm/ppc-pci.h>
+#include <asm/firmware.h>
+
+unsigned long isa_io_base;	/* NULL if no ISA bus */
+EXPORT_SYMBOL(isa_io_base);
+
+/* Cached ISA bridge dev. */
+static struct device_node *isa_bridge_devnode;
+struct pci_dev *isa_bridge_pcidev;
+EXPORT_SYMBOL_GPL(isa_bridge_pcidev);
+
+#define ISA_SPACE_MASK 0x1
+#define ISA_SPACE_IO 0x1
+
+static void __devinit pci_process_ISA_OF_ranges(struct device_node *isa_node,
+						unsigned long phb_io_base_phys)
+{
+	/* We should get some saner parsing here and remove these structs */
+	struct pci_address {
+		u32 a_hi;
+		u32 a_mid;
+		u32 a_lo;
+	};
+
+	struct isa_address {
+		u32 a_hi;
+		u32 a_lo;
+	};
+
+	struct isa_range {
+		struct isa_address isa_addr;
+		struct pci_address pci_addr;
+		unsigned int size;
+	};
+
+	const struct isa_range *range;
+	unsigned long pci_addr;
+	unsigned int isa_addr;
+	unsigned int size;
+	int rlen = 0;
+
+	range = of_get_property(isa_node, "ranges", &rlen);
+	if (range == NULL || (rlen < sizeof(struct isa_range)))
+		goto inval_range;
+
+	/* From "ISA Binding to 1275"
+	 * The ranges property is laid out as an array of elements,
+	 * each of which comprises:
+	 *   cells 0 - 1:	an ISA address
+	 *   cells 2 - 4:	a PCI address
+	 *			(size depending on dev->n_addr_cells)
+	 *   cell 5:		the size of the range
+	 */
+	if ((range->isa_addr.a_hi && ISA_SPACE_MASK) != ISA_SPACE_IO) {
+		range++;
+		rlen -= sizeof(struct isa_range);
+		if (rlen < sizeof(struct isa_range))
+			goto inval_range;
+	}
+	if ((range->isa_addr.a_hi && ISA_SPACE_MASK) != ISA_SPACE_IO)
+		goto inval_range;
+
+	isa_addr = range->isa_addr.a_lo;
+	pci_addr = (unsigned long) range->pci_addr.a_mid << 32 |
+		range->pci_addr.a_lo;
+
+	/* Assume these are both zero. Note: We could fix that and
+	 * do a proper parsing instead ... oh well, that will do for
+	 * now as nobody uses fancy mappings for ISA bridges
+	 */
+	if ((pci_addr != 0) || (isa_addr != 0)) {
+		printk(KERN_ERR "unexpected isa to pci mapping: %s\n",
+		       __FUNCTION__);
+		return;
+	}
+
+	/* Align size and make sure it's cropped to 64K */
+	size = PAGE_ALIGN(range->size);
+	if (size > 0x10000)
+		size = 0x10000;
+
+	printk(KERN_ERR "no ISA IO ranges or unexpected isa range,"
+	       "mapping 64k\n");
+
+	__ioremap_at(phb_io_base_phys, (void *)ISA_IO_BASE,
+		     size, _PAGE_NO_CACHE|_PAGE_GUARDED);
+	return;
+
+inval_range:
+	printk(KERN_ERR "no ISA IO ranges or unexpected isa range,"
+	       "mapping 64k\n");
+	__ioremap_at(phb_io_base_phys, (void *)ISA_IO_BASE,
+		     0x10000, _PAGE_NO_CACHE|_PAGE_GUARDED);
+}
+
+
+/**
+ * isa_bridge_find_early - Find and map the ISA IO space early before
+ *                         main PCI discovery. This is optionally called by
+ *                         the arch code when adding PCI PHBs to get early
+ *                         access to ISA IO ports
+ */
+void __init isa_bridge_find_early(struct pci_controller *hose)
+{
+	struct device_node *np, *parent = NULL, *tmp;
+
+	/* If we already have an ISA bridge, bail off */
+	if (isa_bridge_devnode != NULL)
+		return;
+
+	/* For each "isa" node in the system. Note : we do a search by
+	 * type and not by name. It might be better to do by name but that's
+	 * what the code used to do and I don't want to break too much at
+	 * once. We can look into changing that separately
+	 */
+	for_each_node_by_type(np, "isa") {
+		/* Look for our hose being a parent */
+		for (parent = of_get_parent(np); parent;) {
+			if (parent == hose->arch_data) {
+				of_node_put(parent);
+				break;
+			}
+			tmp = parent;
+			parent = of_get_parent(parent);
+			of_node_put(tmp);
+		}
+		if (parent != NULL)
+			break;
+	}
+	if (np == NULL)
+		return;
+	isa_bridge_devnode = np;
+
+	/* Now parse the "ranges" property and setup the ISA mapping */
+	pci_process_ISA_OF_ranges(np, hose->io_base_phys);
+
+	/* Set the global ISA io base to indicate we have an ISA bridge */
+	isa_io_base = ISA_IO_BASE;
+
+	pr_debug("ISA bridge (early) is %s\n", np->full_name);
+}
+
+/**
+ * isa_bridge_find_late - Find and map the ISA IO space upon discovery of
+ *                        a new ISA bridge
+ */
+static void __devinit isa_bridge_find_late(struct pci_dev *pdev,
+					   struct device_node *devnode)
+{
+	struct pci_controller *hose = pci_bus_to_host(pdev->bus);
+
+	/* Store ISA device node and PCI device */
+	isa_bridge_devnode = of_node_get(devnode);
+	isa_bridge_pcidev = pdev;
+
+	/* Now parse the "ranges" property and setup the ISA mapping */
+	pci_process_ISA_OF_ranges(devnode, hose->io_base_phys);
+
+	/* Set the global ISA io base to indicate we have an ISA bridge */
+	isa_io_base = ISA_IO_BASE;
+
+	pr_debug("ISA bridge (late) is %s on %s\n",
+		 devnode->full_name, pci_name(pdev));
+}
+
+/**
+ * isa_bridge_remove - Remove/unmap an ISA bridge
+ */
+static void isa_bridge_remove(void)
+{
+	pr_debug("ISA bridge removed !\n");
+
+	/* Clear the global ISA io base to indicate that we have no more
+	 * ISA bridge. Note that drivers don't quite handle that, though
+	 * we should probably do something about it. But do we ever really
+	 * have ISA bridges being removed on machines using legacy devices ?
+	 */
+	isa_io_base = ISA_IO_BASE;
+
+	/* Clear references to the bridge */
+	of_node_put(isa_bridge_devnode);
+	isa_bridge_devnode = NULL;
+	isa_bridge_pcidev = NULL;
+
+	/* Unmap the ISA area */
+	__iounmap_at((void *)ISA_IO_BASE, 0x10000);
+}
+
+/**
+ * isa_bridge_notify - Get notified of PCI devices addition/removal
+ */
+static int __devinit isa_bridge_notify(struct notifier_block *nb,
+				       unsigned long action, void *data)
+{
+	struct device *dev = data;
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct device_node *devnode = pci_device_to_OF_node(pdev);
+
+	switch(action) {
+	case BUS_NOTIFY_ADD_DEVICE:
+		/* Check if we have an early ISA device, without PCI dev */
+		if (isa_bridge_devnode && isa_bridge_devnode == devnode &&
+		    !isa_bridge_pcidev) {
+			pr_debug("ISA bridge PCI attached: %s\n",
+				 pci_name(pdev));
+			isa_bridge_pcidev = pdev;
+		}
+
+		/* Check if we have no ISA device, and this happens to be one,
+		 * register it as such if it has an OF device
+		 */
+		if (!isa_bridge_devnode && devnode && devnode->type &&
+		    !strcmp(devnode->type, "isa"))
+			isa_bridge_find_late(pdev, devnode);
+
+		return 0;
+	case BUS_NOTIFY_DEL_DEVICE:
+		/* Check if this our existing ISA device */
+		if (pdev == isa_bridge_pcidev ||
+		    (devnode && devnode == isa_bridge_devnode))
+			isa_bridge_remove();
+		return 0;
+	}
+	return 0;
+}
+
+static struct notifier_block isa_bridge_notifier = {
+	.notifier_call = isa_bridge_notify
+};
+
+/**
+ * isa_bridge_init - register to be notified of ISA bridge addition/removal
+ *
+ */
+static int __init isa_bridge_init(void)
+{
+	if (firmware_has_feature(FW_FEATURE_ISERIES))
+		return 0;
+	bus_register_notifier(&pci_bus_type, &isa_bridge_notifier);
+	return 0;
+}
+arch_initcall(isa_bridge_init);