arch/powerpc/kernel/isa-bridge.c - linux - Git at Google

 /*
  * 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",
 		       __func__);
 		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->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 __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);
	/*
	* 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",
	__func__);
	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->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 __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);