xref: /openbmc/linux/drivers/pci/hotplug/pciehp.h (revision 7ce05074)
1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  * PCI Express Hot Plug Controller Driver
4  *
5  * Copyright (C) 1995,2001 Compaq Computer Corporation
6  * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
7  * Copyright (C) 2001 IBM Corp.
8  * Copyright (C) 2003-2004 Intel Corporation
9  *
10  * All rights reserved.
11  *
12  * Send feedback to <greg@kroah.com>, <kristen.c.accardi@intel.com>
13  *
14  */
15 #ifndef _PCIEHP_H
16 #define _PCIEHP_H
17 
18 #include <linux/types.h>
19 #include <linux/pci.h>
20 #include <linux/pci_hotplug.h>
21 #include <linux/delay.h>
22 #include <linux/mutex.h>
23 #include <linux/rwsem.h>
24 #include <linux/workqueue.h>
25 
26 #include "../pcie/portdrv.h"
27 
28 extern bool pciehp_poll_mode;
29 extern int pciehp_poll_time;
30 
31 /*
32  * Set CONFIG_DYNAMIC_DEBUG=y and boot with 'dyndbg="file pciehp* +p"' to
33  * enable debug messages.
34  */
35 #define ctrl_dbg(ctrl, format, arg...)					\
36 	pci_dbg(ctrl->pcie->port, format, ## arg)
37 #define ctrl_err(ctrl, format, arg...)					\
38 	pci_err(ctrl->pcie->port, format, ## arg)
39 #define ctrl_info(ctrl, format, arg...)					\
40 	pci_info(ctrl->pcie->port, format, ## arg)
41 #define ctrl_warn(ctrl, format, arg...)					\
42 	pci_warn(ctrl->pcie->port, format, ## arg)
43 
44 #define SLOT_NAME_SIZE 10
45 
46 /**
47  * struct controller - PCIe hotplug controller
48  * @pcie: pointer to the controller's PCIe port service device
49  * @slot_cap: cached copy of the Slot Capabilities register
50  * @inband_presence_disabled: In-Band Presence Detect Disable supported by
51  *	controller and disabled per spec recommendation (PCIe r5.0, appendix I
52  *	implementation note)
53  * @slot_ctrl: cached copy of the Slot Control register
54  * @ctrl_lock: serializes writes to the Slot Control register
55  * @cmd_started: jiffies when the Slot Control register was last written;
56  *	the next write is allowed 1 second later, absent a Command Completed
57  *	interrupt (PCIe r4.0, sec 6.7.3.2)
58  * @cmd_busy: flag set on Slot Control register write, cleared by IRQ handler
59  *	on reception of a Command Completed event
60  * @queue: wait queue to wake up on reception of a Command Completed event,
61  *	used for synchronous writes to the Slot Control register
62  * @pending_events: used by the IRQ handler to save events retrieved from the
63  *	Slot Status register for later consumption by the IRQ thread
64  * @notification_enabled: whether the IRQ was requested successfully
65  * @power_fault_detected: whether a power fault was detected by the hardware
66  *	that has not yet been cleared by the user
67  * @poll_thread: thread to poll for slot events if no IRQ is available,
68  *	enabled with pciehp_poll_mode module parameter
69  * @state: current state machine position
70  * @state_lock: protects reads and writes of @state;
71  *	protects scheduling, execution and cancellation of @button_work
72  * @button_work: work item to turn the slot on or off after 5 seconds
73  *	in response to an Attention Button press
74  * @hotplug_slot: structure registered with the PCI hotplug core
75  * @reset_lock: prevents access to the Data Link Layer Link Active bit in the
76  *	Link Status register and to the Presence Detect State bit in the Slot
77  *	Status register during a slot reset which may cause them to flap
78  * @ist_running: flag to keep user request waiting while IRQ thread is running
79  * @request_result: result of last user request submitted to the IRQ thread
80  * @requester: wait queue to wake up on completion of user request,
81  *	used for synchronous slot enable/disable request via sysfs
82  *
83  * PCIe hotplug has a 1:1 relationship between controller and slot, hence
84  * unlike other drivers, the two aren't represented by separate structures.
85  */
86 struct controller {
87 	struct pcie_device *pcie;
88 
89 	u32 slot_cap;				/* capabilities and quirks */
90 	unsigned int inband_presence_disabled:1;
91 
92 	u16 slot_ctrl;				/* control register access */
93 	struct mutex ctrl_lock;
94 	unsigned long cmd_started;
95 	unsigned int cmd_busy:1;
96 	wait_queue_head_t queue;
97 
98 	atomic_t pending_events;		/* event handling */
99 	unsigned int notification_enabled:1;
100 	unsigned int power_fault_detected;
101 	struct task_struct *poll_thread;
102 
103 	u8 state;				/* state machine */
104 	struct mutex state_lock;
105 	struct delayed_work button_work;
106 
107 	struct hotplug_slot hotplug_slot;	/* hotplug core interface */
108 	struct rw_semaphore reset_lock;
109 	unsigned int ist_running;
110 	int request_result;
111 	wait_queue_head_t requester;
112 };
113 
114 /**
115  * DOC: Slot state
116  *
117  * @OFF_STATE: slot is powered off, no subordinate devices are enumerated
118  * @BLINKINGON_STATE: slot will be powered on after the 5 second delay,
119  *	Power Indicator is blinking
120  * @BLINKINGOFF_STATE: slot will be powered off after the 5 second delay,
121  *	Power Indicator is blinking
122  * @POWERON_STATE: slot is currently powering on
123  * @POWEROFF_STATE: slot is currently powering off
124  * @ON_STATE: slot is powered on, subordinate devices have been enumerated
125  */
126 #define OFF_STATE			0
127 #define BLINKINGON_STATE		1
128 #define BLINKINGOFF_STATE		2
129 #define POWERON_STATE			3
130 #define POWEROFF_STATE			4
131 #define ON_STATE			5
132 
133 /**
134  * DOC: Flags to request an action from the IRQ thread
135  *
136  * These are stored together with events read from the Slot Status register,
137  * hence must be greater than its 16-bit width.
138  *
139  * %DISABLE_SLOT: Disable the slot in response to a user request via sysfs or
140  *	an Attention Button press after the 5 second delay
141  * %RERUN_ISR: Used by the IRQ handler to inform the IRQ thread that the
142  *	hotplug port was inaccessible when the interrupt occurred, requiring
143  *	that the IRQ handler is rerun by the IRQ thread after it has made the
144  *	hotplug port accessible by runtime resuming its parents to D0
145  */
146 #define DISABLE_SLOT		(1 << 16)
147 #define RERUN_ISR		(1 << 17)
148 
149 #define ATTN_BUTTN(ctrl)	((ctrl)->slot_cap & PCI_EXP_SLTCAP_ABP)
150 #define POWER_CTRL(ctrl)	((ctrl)->slot_cap & PCI_EXP_SLTCAP_PCP)
151 #define MRL_SENS(ctrl)		((ctrl)->slot_cap & PCI_EXP_SLTCAP_MRLSP)
152 #define ATTN_LED(ctrl)		((ctrl)->slot_cap & PCI_EXP_SLTCAP_AIP)
153 #define PWR_LED(ctrl)		((ctrl)->slot_cap & PCI_EXP_SLTCAP_PIP)
154 #define NO_CMD_CMPL(ctrl)	((ctrl)->slot_cap & PCI_EXP_SLTCAP_NCCS)
155 #define PSN(ctrl)		(((ctrl)->slot_cap & PCI_EXP_SLTCAP_PSN) >> 19)
156 
157 void pciehp_request(struct controller *ctrl, int action);
158 void pciehp_handle_button_press(struct controller *ctrl);
159 void pciehp_handle_disable_request(struct controller *ctrl);
160 void pciehp_handle_presence_or_link_change(struct controller *ctrl, u32 events);
161 int pciehp_configure_device(struct controller *ctrl);
162 void pciehp_unconfigure_device(struct controller *ctrl, bool presence);
163 void pciehp_queue_pushbutton_work(struct work_struct *work);
164 struct controller *pcie_init(struct pcie_device *dev);
165 int pcie_init_notification(struct controller *ctrl);
166 void pcie_shutdown_notification(struct controller *ctrl);
167 void pcie_clear_hotplug_events(struct controller *ctrl);
168 void pcie_enable_interrupt(struct controller *ctrl);
169 void pcie_disable_interrupt(struct controller *ctrl);
170 int pciehp_power_on_slot(struct controller *ctrl);
171 void pciehp_power_off_slot(struct controller *ctrl);
172 void pciehp_get_power_status(struct controller *ctrl, u8 *status);
173 
174 #define INDICATOR_NOOP -1	/* Leave indicator unchanged */
175 void pciehp_set_indicators(struct controller *ctrl, int pwr, int attn);
176 
177 void pciehp_get_latch_status(struct controller *ctrl, u8 *status);
178 int pciehp_query_power_fault(struct controller *ctrl);
179 int pciehp_card_present(struct controller *ctrl);
180 int pciehp_card_present_or_link_active(struct controller *ctrl);
181 int pciehp_check_link_status(struct controller *ctrl);
182 int pciehp_check_link_active(struct controller *ctrl);
183 void pciehp_release_ctrl(struct controller *ctrl);
184 
185 int pciehp_sysfs_enable_slot(struct hotplug_slot *hotplug_slot);
186 int pciehp_sysfs_disable_slot(struct hotplug_slot *hotplug_slot);
187 int pciehp_reset_slot(struct hotplug_slot *hotplug_slot, int probe);
188 int pciehp_get_attention_status(struct hotplug_slot *hotplug_slot, u8 *status);
189 int pciehp_set_raw_indicator_status(struct hotplug_slot *h_slot, u8 status);
190 int pciehp_get_raw_indicator_status(struct hotplug_slot *h_slot, u8 *status);
191 
192 static inline const char *slot_name(struct controller *ctrl)
193 {
194 	return hotplug_slot_name(&ctrl->hotplug_slot);
195 }
196 
197 static inline struct controller *to_ctrl(struct hotplug_slot *hotplug_slot)
198 {
199 	return container_of(hotplug_slot, struct controller, hotplug_slot);
200 }
201 
202 #endif				/* _PCIEHP_H */
203