/* * 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);