From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Andr=C3=A9=20Fabian=20Silva=20Delgado?= Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- arch/powerpc/kernel/isa-bridge.c | 266 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 266 insertions(+) create mode 100644 arch/powerpc/kernel/isa-bridge.c (limited to 'arch/powerpc/kernel/isa-bridge.c') diff --git a/arch/powerpc/kernel/isa-bridge.c b/arch/powerpc/kernel/isa-bridge.c new file mode 100644 index 000000000..0f1997097 --- /dev/null +++ b/arch/powerpc/kernel/isa-bridge.c @@ -0,0 +1,266 @@ +/* + * Routines for tracking a legacy ISA bridge + * + * Copyrigh 2007 Benjamin Herrenschmidt , IBM Corp. + * + * Some bits and pieces moved over from pci_64.c + * + * Copyrigh 2003 Anton Blanchard , 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 +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include + +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 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", + __func__); + return; + } + + /* Align size and make sure it's cropped to 64K */ + size = PAGE_ALIGN(range->size); + if (size > 0x10000) + size = 0x10000; + + __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->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 */ + 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 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 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) +{ + bus_register_notifier(&pci_bus_type, &isa_bridge_notifier); + return 0; +} +arch_initcall(isa_bridge_init); -- cgit v1.2.3