// 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 (vmap_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);