cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

s390_pci_hpc.c (3066B)

      1// SPDX-License-Identifier: GPL-2.0+
      2/*
      3 * PCI Hot Plug Controller Driver for System z
      4 *
      5 * Copyright 2012 IBM Corp.
      6 *
      7 * Author(s):
      8 *   Jan Glauber <jang@linux.vnet.ibm.com>
      9 */
     10
     11#define KMSG_COMPONENT "zpci"
     12#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
     13
     14#include <linux/kernel.h>
     15#include <linux/slab.h>
     16#include <linux/pci.h>
     17#include <linux/pci_hotplug.h>
     18#include <asm/pci_debug.h>
     19#include <asm/sclp.h>
     20
     21#define SLOT_NAME_SIZE	10
     22
     23static int enable_slot(struct hotplug_slot *hotplug_slot)
     24{
     25	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
     26					     hotplug_slot);
     27	int rc;
     28
     29	if (zdev->state != ZPCI_FN_STATE_STANDBY)
     30		return -EIO;
     31
     32	rc = sclp_pci_configure(zdev->fid);
     33	zpci_dbg(3, "conf fid:%x, rc:%d\n", zdev->fid, rc);
     34	if (rc)
     35		return rc;
     36	zdev->state = ZPCI_FN_STATE_CONFIGURED;
     37
     38	return zpci_scan_configured_device(zdev, zdev->fh);
     39}
     40
     41static int disable_slot(struct hotplug_slot *hotplug_slot)
     42{
     43	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
     44					     hotplug_slot);
     45	struct pci_dev *pdev;
     46
     47	if (zdev->state != ZPCI_FN_STATE_CONFIGURED)
     48		return -EIO;
     49
     50	pdev = pci_get_slot(zdev->zbus->bus, zdev->devfn);
     51	if (pdev && pci_num_vf(pdev)) {
     52		pci_dev_put(pdev);
     53		return -EBUSY;
     54	}
     55	pci_dev_put(pdev);
     56
     57	return zpci_deconfigure_device(zdev);
     58}
     59
     60static int reset_slot(struct hotplug_slot *hotplug_slot, bool probe)
     61{
     62	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
     63					     hotplug_slot);
     64
     65	if (zdev->state != ZPCI_FN_STATE_CONFIGURED)
     66		return -EIO;
     67	/*
     68	 * We can't take the zdev->lock as reset_slot may be called during
     69	 * probing and/or device removal which already happens under the
     70	 * zdev->lock. Instead the user should use the higher level
     71	 * pci_reset_function() or pci_bus_reset() which hold the PCI device
     72	 * lock preventing concurrent removal. If not using these functions
     73	 * holding the PCI device lock is required.
     74	 */
     75
     76	/* As long as the function is configured we can reset */
     77	if (probe)
     78		return 0;
     79
     80	return zpci_hot_reset_device(zdev);
     81}
     82
     83static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
     84{
     85	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
     86					     hotplug_slot);
     87
     88	*value = zpci_is_device_configured(zdev) ? 1 : 0;
     89	return 0;
     90}
     91
     92static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
     93{
     94	/* if the slot exits it always contains a function */
     95	*value = 1;
     96	return 0;
     97}
     98
     99static const struct hotplug_slot_ops s390_hotplug_slot_ops = {
    100	.enable_slot =		enable_slot,
    101	.disable_slot =		disable_slot,
    102	.reset_slot =		reset_slot,
    103	.get_power_status =	get_power_status,
    104	.get_adapter_status =	get_adapter_status,
    105};
    106
    107int zpci_init_slot(struct zpci_dev *zdev)
    108{
    109	char name[SLOT_NAME_SIZE];
    110	struct zpci_bus *zbus = zdev->zbus;
    111
    112	zdev->hotplug_slot.ops = &s390_hotplug_slot_ops;
    113
    114	snprintf(name, SLOT_NAME_SIZE, "%08x", zdev->fid);
    115	return pci_hp_register(&zdev->hotplug_slot, zbus->bus,
    116			       zdev->devfn, name);
    117}
    118
    119void zpci_exit_slot(struct zpci_dev *zdev)
    120{
    121	pci_hp_deregister(&zdev->hotplug_slot);
    122}