xref: /openbmc/linux/drivers/pci/hotplug/pciehp.h (revision 165f2d28)
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  * @slot_ctrl: cached copy of the Slot Control register
51  * @ctrl_lock: serializes writes to the Slot Control register
52  * @cmd_started: jiffies when the Slot Control register was last written;
53  *	the next write is allowed 1 second later, absent a Command Completed
54  *	interrupt (PCIe r4.0, sec 6.7.3.2)
55  * @cmd_busy: flag set on Slot Control register write, cleared by IRQ handler
56  *	on reception of a Command Completed event
57  * @queue: wait queue to wake up on reception of a Command Completed event,
58  *	used for synchronous writes to the Slot Control register
59  * @pending_events: used by the IRQ handler to save events retrieved from the
60  *	Slot Status register for later consumption by the IRQ thread
61  * @notification_enabled: whether the IRQ was requested successfully
62  * @power_fault_detected: whether a power fault was detected by the hardware
63  *	that has not yet been cleared by the user
64  * @poll_thread: thread to poll for slot events if no IRQ is available,
65  *	enabled with pciehp_poll_mode module parameter
66  * @state: current state machine position
67  * @state_lock: protects reads and writes of @state;
68  *	protects scheduling, execution and cancellation of @button_work
69  * @button_work: work item to turn the slot on or off after 5 seconds
70  *	in response to an Attention Button press
71  * @hotplug_slot: structure registered with the PCI hotplug core
72  * @reset_lock: prevents access to the Data Link Layer Link Active bit in the
73  *	Link Status register and to the Presence Detect State bit in the Slot
74  *	Status register during a slot reset which may cause them to flap
75  * @ist_running: flag to keep user request waiting while IRQ thread is running
76  * @request_result: result of last user request submitted to the IRQ thread
77  * @requester: wait queue to wake up on completion of user request,
78  *	used for synchronous slot enable/disable request via sysfs
79  *
80  * PCIe hotplug has a 1:1 relationship between controller and slot, hence
81  * unlike other drivers, the two aren't represented by separate structures.
82  */
83 struct controller {
84 	struct pcie_device *pcie;
85 
86 	u32 slot_cap;				/* capabilities and quirks */
87 	unsigned int inband_presence_disabled:1;
88 
89 	u16 slot_ctrl;				/* control register access */
90 	struct mutex ctrl_lock;
91 	unsigned long cmd_started;
92 	unsigned int cmd_busy:1;
93 	wait_queue_head_t queue;
94 
95 	atomic_t pending_events;		/* event handling */
96 	unsigned int notification_enabled:1;
97 	unsigned int power_fault_detected;
98 	struct task_struct *poll_thread;
99 
100 	u8 state;				/* state machine */
101 	struct mutex state_lock;
102 	struct delayed_work button_work;
103 
104 	struct hotplug_slot hotplug_slot;	/* hotplug core interface */
105 	struct rw_semaphore reset_lock;
106 	unsigned int ist_running;
107 	int request_result;
108 	wait_queue_head_t requester;
109 };
110 
111 /**
112  * DOC: Slot state
113  *
114  * @OFF_STATE: slot is powered off, no subordinate devices are enumerated
115  * @BLINKINGON_STATE: slot will be powered on after the 5 second delay,
116  *	Power Indicator is blinking
117  * @BLINKINGOFF_STATE: slot will be powered off after the 5 second delay,
118  *	Power Indicator is blinking
119  * @POWERON_STATE: slot is currently powering on
120  * @POWEROFF_STATE: slot is currently powering off
121  * @ON_STATE: slot is powered on, subordinate devices have been enumerated
122  */
123 #define OFF_STATE			0
124 #define BLINKINGON_STATE		1
125 #define BLINKINGOFF_STATE		2
126 #define POWERON_STATE			3
127 #define POWEROFF_STATE			4
128 #define ON_STATE			5
129 
130 /**
131  * DOC: Flags to request an action from the IRQ thread
132  *
133  * These are stored together with events read from the Slot Status register,
134  * hence must be greater than its 16-bit width.
135  *
136  * %DISABLE_SLOT: Disable the slot in response to a user request via sysfs or
137  *	an Attention Button press after the 5 second delay
138  * %RERUN_ISR: Used by the IRQ handler to inform the IRQ thread that the
139  *	hotplug port was inaccessible when the interrupt occurred, requiring
140  *	that the IRQ handler is rerun by the IRQ thread after it has made the
141  *	hotplug port accessible by runtime resuming its parents to D0
142  */
143 #define DISABLE_SLOT		(1 << 16)
144 #define RERUN_ISR		(1 << 17)
145 
146 #define ATTN_BUTTN(ctrl)	((ctrl)->slot_cap & PCI_EXP_SLTCAP_ABP)
147 #define POWER_CTRL(ctrl)	((ctrl)->slot_cap & PCI_EXP_SLTCAP_PCP)
148 #define MRL_SENS(ctrl)		((ctrl)->slot_cap & PCI_EXP_SLTCAP_MRLSP)
149 #define ATTN_LED(ctrl)		((ctrl)->slot_cap & PCI_EXP_SLTCAP_AIP)
150 #define PWR_LED(ctrl)		((ctrl)->slot_cap & PCI_EXP_SLTCAP_PIP)
151 #define HP_SUPR_RM(ctrl)	((ctrl)->slot_cap & PCI_EXP_SLTCAP_HPS)
152 #define EMI(ctrl)		((ctrl)->slot_cap & PCI_EXP_SLTCAP_EIP)
153 #define NO_CMD_CMPL(ctrl)	((ctrl)->slot_cap & PCI_EXP_SLTCAP_NCCS)
154 #define PSN(ctrl)		(((ctrl)->slot_cap & PCI_EXP_SLTCAP_PSN) >> 19)
155 
156 void pciehp_request(struct controller *ctrl, int action);
157 void pciehp_handle_button_press(struct controller *ctrl);
158 void pciehp_handle_disable_request(struct controller *ctrl);
159 void pciehp_handle_presence_or_link_change(struct controller *ctrl, u32 events);
160 int pciehp_configure_device(struct controller *ctrl);
161 void pciehp_unconfigure_device(struct controller *ctrl, bool presence);
162 void pciehp_queue_pushbutton_work(struct work_struct *work);
163 struct controller *pcie_init(struct pcie_device *dev);
164 int pcie_init_notification(struct controller *ctrl);
165 void pcie_shutdown_notification(struct controller *ctrl);
166 void pcie_clear_hotplug_events(struct controller *ctrl);
167 void pcie_enable_interrupt(struct controller *ctrl);
168 void pcie_disable_interrupt(struct controller *ctrl);
169 int pciehp_power_on_slot(struct controller *ctrl);
170 void pciehp_power_off_slot(struct controller *ctrl);
171 void pciehp_get_power_status(struct controller *ctrl, u8 *status);
172 
173 #define INDICATOR_NOOP -1	/* Leave indicator unchanged */
174 void pciehp_set_indicators(struct controller *ctrl, int pwr, int attn);
175 
176 void pciehp_get_latch_status(struct controller *ctrl, u8 *status);
177 int pciehp_query_power_fault(struct controller *ctrl);
178 int pciehp_card_present(struct controller *ctrl);
179 int pciehp_card_present_or_link_active(struct controller *ctrl);
180 int pciehp_check_link_status(struct controller *ctrl);
181 int pciehp_check_link_active(struct controller *ctrl);
182 void pciehp_release_ctrl(struct controller *ctrl);
183 
184 int pciehp_sysfs_enable_slot(struct hotplug_slot *hotplug_slot);
185 int pciehp_sysfs_disable_slot(struct hotplug_slot *hotplug_slot);
186 int pciehp_reset_slot(struct hotplug_slot *hotplug_slot, int probe);
187 int pciehp_get_attention_status(struct hotplug_slot *hotplug_slot, u8 *status);
188 int pciehp_set_raw_indicator_status(struct hotplug_slot *h_slot, u8 status);
189 int pciehp_get_raw_indicator_status(struct hotplug_slot *h_slot, u8 *status);
190 
191 static inline const char *slot_name(struct controller *ctrl)
192 {
193 	return hotplug_slot_name(&ctrl->hotplug_slot);
194 }
195 
196 static inline struct controller *to_ctrl(struct hotplug_slot *hotplug_slot)
197 {
198 	return container_of(hotplug_slot, struct controller, hotplug_slot);
199 }
200 
201 #endif				/* _PCIEHP_H */
202