// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Routines for tracking a legacy ISA bridge
*
* Copyrigh 2007 Benjamin Herrenschmidt <[email protected]>, IBM Corp.
*
* Some bits and pieces moved over from pci_64.c
*
* Copyrigh 2003 Anton Blanchard <[email protected]>, 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);
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