linux-loongson/include/linux/pci_hotplug.h
Lukas Wunner c2f9de5e2d PCI: Move is_pciehp check out of pciehp_is_native()
pci_bridge_d3_possible() seeks to forbid runtime power management on:

* Non Hot-Plug Capable PCIe ports which are nevertheless ACPI slots
  (recognizable as: bridge->is_hotplug_bridge && !bridge->is_pciehp)

* Hot-Plug Capable PCIe ports for which platform firmware has not granted
  PCIe Native Hot-Plug control to the operating system
  (recognizable as: bridge->is_pciehp && !pciehp_is_native(bridge))

Somewhat confusingly, the check for is_hotplug_bridge is in
pci_bridge_d3_possible(), whereas the one for is_pciehp is in
pciehp_is_native().

For clarity, check is_pciehp directly in pci_bridge_d3_possible()
(and in the other caller of pciehp_is_native(), hotplug_is_native()).

Rephrase the code comment preceding these checks to no longer mention
"System Management Mode", which is an x86 term inappropriate in generic
PCI code.  Likewise no longer mention "Thunderbolt on non-Macs", because
there is nothing Thunderbolt-specific about these checks.  It used to be
the case that non-Macs relied on the platform for Thunderbolt tunnel
management and hotplug, but they've since moved to OS-native tunnel
management (as Macs always have), hence the code comment is no longer
accurate.

There is a subsequent check for is_hotplug_bridge further down in
pci_bridge_d3_possible().  Change the check to is_pciehp because any
ports matching "bridge->is_hotplug_bridge && !bridge->is_pciehp" are
already filtered out at the top of the function.

Do the same for another check in acpi_pci_bridge_d3(), which is called
from pci_bridge_d3_possible() via platform_pci_bridge_d3().

No functional change intended.

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/18b2c2110ad0f27a34b189d793310b9c4f2f24a0.1752390102.git.lukas@wunner.de
2025-07-29 11:45:39 -05:00

111 lines
4.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0+ */
/*
* PCI HotPlug Core Functions
*
* Copyright (C) 1995,2001 Compaq Computer Corporation
* Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
* Copyright (C) 2001 IBM Corp.
*
* All rights reserved.
*
* Send feedback to <kristen.c.accardi@intel.com>
*
*/
#ifndef _PCI_HOTPLUG_H
#define _PCI_HOTPLUG_H
/**
* struct hotplug_slot_ops -the callbacks that the hotplug pci core can use
* @enable_slot: Called when the user wants to enable a specific pci slot
* @disable_slot: Called when the user wants to disable a specific pci slot
* @set_attention_status: Called to set the specific slot's attention LED to
* the specified value
* @hardware_test: Called to run a specified hardware test on the specified
* slot.
* @get_power_status: Called to get the current power status of a slot.
* @get_attention_status: Called to get the current attention status of a slot.
* @get_latch_status: Called to get the current latch status of a slot.
* @get_adapter_status: Called to get see if an adapter is present in the slot or not.
* @reset_slot: Optional interface to allow override of a bus reset for the
* slot for cases where a secondary bus reset can result in spurious
* hotplug events or where a slot can be reset independent of the bus.
*
* The table of function pointers that is passed to the hotplug pci core by a
* hotplug pci driver. These functions are called by the hotplug pci core when
* the user wants to do something to a specific slot (query it for information,
* set an LED, enable / disable power, etc.)
*/
struct hotplug_slot_ops {
int (*enable_slot) (struct hotplug_slot *slot);
int (*disable_slot) (struct hotplug_slot *slot);
int (*set_attention_status) (struct hotplug_slot *slot, u8 value);
int (*hardware_test) (struct hotplug_slot *slot, u32 value);
int (*get_power_status) (struct hotplug_slot *slot, u8 *value);
int (*get_attention_status) (struct hotplug_slot *slot, u8 *value);
int (*get_latch_status) (struct hotplug_slot *slot, u8 *value);
int (*get_adapter_status) (struct hotplug_slot *slot, u8 *value);
int (*reset_slot) (struct hotplug_slot *slot, bool probe);
};
/**
* struct hotplug_slot - used to register a physical slot with the hotplug pci core
* @ops: pointer to the &struct hotplug_slot_ops to be used for this slot
* @pci_slot: represents a physical slot
* @owner: The module owner of this structure
* @mod_name: The module name (KBUILD_MODNAME) of this structure
*/
struct hotplug_slot {
const struct hotplug_slot_ops *ops;
/* Variables below this are for use only by the hotplug pci core. */
struct pci_slot *pci_slot;
struct module *owner;
const char *mod_name;
};
static inline const char *hotplug_slot_name(const struct hotplug_slot *slot)
{
return pci_slot_name(slot->pci_slot);
}
int __pci_hp_register(struct hotplug_slot *slot, struct pci_bus *pbus, int nr,
const char *name, struct module *owner,
const char *mod_name);
int __pci_hp_initialize(struct hotplug_slot *slot, struct pci_bus *bus, int nr,
const char *name, struct module *owner,
const char *mod_name);
int pci_hp_add(struct hotplug_slot *slot);
void pci_hp_del(struct hotplug_slot *slot);
void pci_hp_destroy(struct hotplug_slot *slot);
void pci_hp_deregister(struct hotplug_slot *slot);
/* use a define to avoid include chaining to get THIS_MODULE & friends */
#define pci_hp_register(slot, pbus, devnr, name) \
__pci_hp_register(slot, pbus, devnr, name, THIS_MODULE, KBUILD_MODNAME)
#define pci_hp_initialize(slot, bus, nr, name) \
__pci_hp_initialize(slot, bus, nr, name, THIS_MODULE, KBUILD_MODNAME)
#ifdef CONFIG_ACPI
#include <linux/acpi.h>
bool pciehp_is_native(struct pci_dev *bridge);
int acpi_get_hp_hw_control_from_firmware(struct pci_dev *bridge);
bool shpchp_is_native(struct pci_dev *bridge);
int acpi_pci_check_ejectable(struct pci_bus *pbus, acpi_handle handle);
int acpi_pci_detect_ejectable(acpi_handle handle);
#else
static inline int acpi_get_hp_hw_control_from_firmware(struct pci_dev *bridge)
{
return 0;
}
static inline bool pciehp_is_native(struct pci_dev *bridge) { return true; }
static inline bool shpchp_is_native(struct pci_dev *bridge) { return true; }
#endif
static inline bool hotplug_is_native(struct pci_dev *bridge)
{
return (bridge->is_pciehp && pciehp_is_native(bridge)) ||
shpchp_is_native(bridge);
}
#endif