1 files changed, 276 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/isa-bridge.c b/arch/powerpc/kernel/isa-bridge.c
new file mode 100644
index 0000000000..48e0eaf1ad
--- /dev/null
+++ b/arch/powerpc/kernel/isa-bridge.c
@@ -0,0 +1,276 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * 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.
+ */
+
+#define DEBUG
+
+#include <linux/kernel.h>
+#include <linux/pci.h>
+#include <linux/string.h>
+#include <linux/export.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/notifier.h>
+#include <linux/of_address.h>
+#include <linux/vmalloc.h>
+
+#include <asm/processor.h>
+#include <asm/io.h>
+#include <asm/pci-bridge.h>
+#include <asm/machdep.h>
+#include <asm/ppc-pci.h>
+#include <asm/isa-bridge.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 remap_isa_base(phys_addr_t pa, unsigned long size)
+{
+	WARN_ON_ONCE(ISA_IO_BASE & ~PAGE_MASK);
+	WARN_ON_ONCE(pa & ~PAGE_MASK);
+	WARN_ON_ONCE(size & ~PAGE_MASK);
+
+	if (slab_is_available()) {
+		if (ioremap_page_range(ISA_IO_BASE, ISA_IO_BASE + size, pa,
+				pgprot_noncached(PAGE_KERNEL)))
+			vunmap_range(ISA_IO_BASE, ISA_IO_BASE + size);
+	} else {
+		early_ioremap_range(ISA_IO_BASE, pa, size,
+				pgprot_noncached(PAGE_KERNEL));
+	}
+}
+
+static int process_ISA_OF_ranges(struct device_node *isa_node,
+				 unsigned long phb_io_base_phys)
+{
+	unsigned int size;
+	struct of_range_parser parser;
+	struct of_range range;
+
+	if (of_range_parser_init(&parser, isa_node))
+		goto inval_range;
+
+	for_each_of_range(&parser, &range) {
+		if ((range.flags & ISA_SPACE_MASK) != ISA_SPACE_IO)
+			continue;
+
+		if (range.cpu_addr == OF_BAD_ADDR) {
+			pr_err("ISA: Bad CPU mapping: %s\n", __func__);
+			return -EINVAL;
+		}
+
+		/* We need page alignment */
+		if ((range.bus_addr & ~PAGE_MASK) || (range.cpu_addr & ~PAGE_MASK)) {
+			pr_warn("ISA: bridge %pOF has non aligned IO range\n", isa_node);
+			return -EINVAL;
+		}
+
+		/* Align size and make sure it's cropped to 64K */
+		size = PAGE_ALIGN(range.size);
+		if (size > 0x10000)
+			size = 0x10000;
+
+		if (!phb_io_base_phys)
+			phb_io_base_phys = range.cpu_addr;
+
+		remap_isa_base(phb_io_base_phys, size);
+		return 0;
+	}
+
+inval_range:
+	if (phb_io_base_phys) {
+		pr_err("no ISA IO ranges or unexpected isa range, mapping 64k\n");
+		remap_isa_base(phb_io_base_phys, 0x10000);
+		return 0;
+	}
+	return -EINVAL;
+}
+
+
+/**
+ * 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->dn) {
+				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 */
+	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 %pOF\n", np);
+}
+
+/**
+ * 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_init_non_pci(struct device_node *np)
+{
+	int ret;
+
+	/* If we already have an ISA bridge, bail off */
+	if (isa_bridge_devnode != NULL)
+		return;
+
+	ret = process_ISA_OF_ranges(np, 0);
+	if (ret)
+		return;
+
+	/* Got it */
+	isa_bridge_devnode = np;
+
+	/* Set the global ISA io base to indicate we have an ISA bridge
+	 * and map it
+	 */
+	isa_io_base = ISA_IO_BASE;
+
+	pr_debug("ISA: Non-PCI bridge is %pOF\n", np);
+}
+
+/**
+ * isa_bridge_find_late - Find and map the ISA IO space upon discovery of
+ *                        a new ISA bridge
+ */
+static void 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 */
+	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 %pOF on %s\n",
+		 devnode, 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 */
+	vunmap_range(ISA_IO_BASE, ISA_IO_BASE + 0x10000);
+}
+
+/**
+ * isa_bridge_notify - Get notified of PCI devices addition/removal
+ */
+static int 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 && of_node_is_type(devnode, "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)
+{
+	bus_register_notifier(&pci_bus_type, &isa_bridge_notifier);
+	return 0;
+}
+arch_initcall(isa_bridge_init);