drivers/pci/hotplug/cpci_hotplug_pci.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * CompactPCI Hot Plug Driver PCI functions
 *
 * Copyright (C) 2002,2005 by SOMA Networks, Inc.
 *
 * All rights reserved.
 *
 * Send feedback to <scottm@somanetworks.com>
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/pci_hotplug.h>
#include <linux/proc_fs.h>
#include "../pci.h"
#include "cpci_hotplug.h"

#define MY_NAME	"cpci_hotplug"

#define dbg(format, arg...)					\
	do {							\
		if (cpci_debug)					\
			printk(KERN_DEBUG "%s: " format "\n",	\
				MY_NAME, ## arg);		\
	} while (0)
#define err(format, arg...) printk(KERN_ERR "%s: " format "\n", MY_NAME, ## arg)
#define info(format, arg...) printk(KERN_INFO "%s: " format "\n", MY_NAME, ## arg)
#define warn(format, arg...) printk(KERN_WARNING "%s: " format "\n", MY_NAME, ## arg)


u8 cpci_get_attention_status(struct slot *slot)
{
	int hs_cap;
	u16 hs_csr;

	hs_cap = pci_bus_find_capability(slot->bus,
					 slot->devfn,
					 PCI_CAP_ID_CHSWP);
	if (!hs_cap)
		return 0;

	if (pci_bus_read_config_word(slot->bus,
				     slot->devfn,
				     hs_cap + 2,
				     &hs_csr))
		return 0;

	return hs_csr & 0x0008 ? 1 : 0;
}

int cpci_set_attention_status(struct slot *slot, int status)
{
	int hs_cap;
	u16 hs_csr;

	hs_cap = pci_bus_find_capability(slot->bus,
					 slot->devfn,
					 PCI_CAP_ID_CHSWP);
	if (!hs_cap)
		return 0;
	if (pci_bus_read_config_word(slot->bus,
				     slot->devfn,
				     hs_cap + 2,
				     &hs_csr))
		return 0;
	if (status)
		hs_csr |= HS_CSR_LOO;
	else
		hs_csr &= ~HS_CSR_LOO;
	if (pci_bus_write_config_word(slot->bus,
				      slot->devfn,
				      hs_cap + 2,
				      hs_csr))
		return 0;
	return 1;
}

u16 cpci_get_hs_csr(struct slot *slot)
{
	int hs_cap;
	u16 hs_csr;

	hs_cap = pci_bus_find_capability(slot->bus,
					 slot->devfn,
					 PCI_CAP_ID_CHSWP);
	if (!hs_cap)
		return 0xFFFF;
	if (pci_bus_read_config_word(slot->bus,
				     slot->devfn,
				     hs_cap + 2,
				     &hs_csr))
		return 0xFFFF;
	return hs_csr;
}

int cpci_check_and_clear_ins(struct slot *slot)
{
	int hs_cap;
	u16 hs_csr;
	int ins = 0;

	hs_cap = pci_bus_find_capability(slot->bus,
					 slot->devfn,
					 PCI_CAP_ID_CHSWP);
	if (!hs_cap)
		return 0;
	if (pci_bus_read_config_word(slot->bus,
				     slot->devfn,
				     hs_cap + 2,
				     &hs_csr))
		return 0;
	if (hs_csr & HS_CSR_INS) {
		/* Clear INS (by setting it) */
		if (pci_bus_write_config_word(slot->bus,
					      slot->devfn,
					      hs_cap + 2,
					      hs_csr))
			ins = 0;
		else
			ins = 1;
	}
	return ins;
}

int cpci_check_ext(struct slot *slot)
{
	int hs_cap;
	u16 hs_csr;
	int ext = 0;

	hs_cap = pci_bus_find_capability(slot->bus,
					 slot->devfn,
					 PCI_CAP_ID_CHSWP);
	if (!hs_cap)
		return 0;
	if (pci_bus_read_config_word(slot->bus,
				     slot->devfn,
				     hs_cap + 2,
				     &hs_csr))
		return 0;
	if (hs_csr & HS_CSR_EXT)
		ext = 1;
	return ext;
}

int cpci_clear_ext(struct slot *slot)
{
	int hs_cap;
	u16 hs_csr;

	hs_cap = pci_bus_find_capability(slot->bus,
					 slot->devfn,
					 PCI_CAP_ID_CHSWP);
	if (!hs_cap)
		return -ENODEV;
	if (pci_bus_read_config_word(slot->bus,
				     slot->devfn,
				     hs_cap + 2,
				     &hs_csr))
		return -ENODEV;
	if (hs_csr & HS_CSR_EXT) {
		/* Clear EXT (by setting it) */
		if (pci_bus_write_config_word(slot->bus,
					      slot->devfn,
					      hs_cap + 2,
					      hs_csr))
			return -ENODEV;
	}
	return 0;
}

int cpci_led_on(struct slot *slot)
{
	int hs_cap;
	u16 hs_csr;

	hs_cap = pci_bus_find_capability(slot->bus,
					 slot->devfn,
					 PCI_CAP_ID_CHSWP);
	if (!hs_cap)
		return -ENODEV;
	if (pci_bus_read_config_word(slot->bus,
				     slot->devfn,
				     hs_cap + 2,
				     &hs_csr))
		return -ENODEV;
	if ((hs_csr & HS_CSR_LOO) != HS_CSR_LOO) {
		hs_csr |= HS_CSR_LOO;
		if (pci_bus_write_config_word(slot->bus,
					      slot->devfn,
					      hs_cap + 2,
					      hs_csr)) {
			err("Could not set LOO for slot %s", slot_name(slot));
			return -ENODEV;
		}
	}
	return 0;
}

int cpci_led_off(struct slot *slot)
{
	int hs_cap;
	u16 hs_csr;

	hs_cap = pci_bus_find_capability(slot->bus,
					 slot->devfn,
					 PCI_CAP_ID_CHSWP);
	if (!hs_cap)
		return -ENODEV;
	if (pci_bus_read_config_word(slot->bus,
				     slot->devfn,
				     hs_cap + 2,
				     &hs_csr))
		return -ENODEV;
	if (hs_csr & HS_CSR_LOO) {
		hs_csr &= ~HS_CSR_LOO;
		if (pci_bus_write_config_word(slot->bus,
					      slot->devfn,
					      hs_cap + 2,
					      hs_csr)) {
			err("Could not clear LOO for slot %s", slot_name(slot));
			return -ENODEV;
		}
	}
	return 0;
}


/*
 * Device configuration functions
 */

int cpci_configure_slot(struct slot *slot)
{
	struct pci_dev *dev;
	struct pci_bus *parent;
	int ret = 0;

	dbg("%s - enter", __func__);

	pci_lock_rescan_remove();

	if (slot->dev == NULL) {
		dbg("pci_dev null, finding %02x:%02x:%x",
		    slot->bus->number, PCI_SLOT(slot->devfn), PCI_FUNC(slot->devfn));
		slot->dev = pci_get_slot(slot->bus, slot->devfn);
	}

	/* Still NULL? Well then scan for it! */
	if (slot->dev == NULL) {
		int n;
		dbg("pci_dev still null");

		/*
		 * This will generate pci_dev structures for all functions, but
		 * we will only call this case when lookup fails.
		 */
		n = pci_scan_slot(slot->bus, slot->devfn);
		dbg("%s: pci_scan_slot returned %d", __func__, n);
		slot->dev = pci_get_slot(slot->bus, slot->devfn);
		if (slot->dev == NULL) {
			err("Could not find PCI device for slot %02x", slot->number);
			ret = -ENODEV;
			goto out;
		}
	}
	parent = slot->dev->bus;

	for_each_pci_bridge(dev, parent) {
		if (PCI_SLOT(dev->devfn) == PCI_SLOT(slot->devfn))
			pci_hp_add_bridge(dev);
	}

	pci_assign_unassigned_bridge_resources(parent->self);

	pci_bus_add_devices(parent);

 out:
	pci_unlock_rescan_remove();
	dbg("%s - exit", __func__);
	return ret;
}

int cpci_unconfigure_slot(struct slot *slot)
{
	struct pci_dev *dev, *temp;

	dbg("%s - enter", __func__);
	if (!slot->dev) {
		err("No device for slot %02x\n", slot->number);
		return -ENODEV;
	}

	pci_lock_rescan_remove();

	list_for_each_entry_safe(dev, temp, &slot->bus->devices, bus_list) {
		if (PCI_SLOT(dev->devfn) != PCI_SLOT(slot->devfn))
			continue;
		pci_dev_get(dev);
		pci_stop_and_remove_bus_device(dev);
		pci_dev_put(dev);
	}
	pci_dev_put(slot->dev);
	slot->dev = NULL;

	pci_unlock_rescan_remove();

	dbg("%s - exit", __func__);
	return 0;
}