add new system file

hc

2024-02-20 102a0743326a03cd1a1202ceda21e175b7d3575c

 kernel/drivers/pci/hotplug/pciehp_pci.c
..
..
@@ -13,20 +13,28 @@
13
13
  *
14
14
  */
15
15
 
16
-#include <linux/module.h>
16
+#define dev_fmt(fmt) "pciehp: " fmt
17
+
17
18
 #include <linux/kernel.h>
18
19
 #include <linux/types.h>
19
20
 #include <linux/pci.h>
20
21
 #include "../pci.h"
21
22
 #include "pciehp.h"
22
23
 
23
-int pciehp_configure_device(struct slot *p_slot)
24
+/**
25
+ * pciehp_configure_device() - enumerate PCI devices below a hotplug bridge
26
+ * @ctrl: PCIe hotplug controller
27
+ *
28
+ * Enumerate PCI devices below a hotplug bridge and add them to the system.
29
+ * Return 0 on success, %-EEXIST if the devices are already enumerated or
30
+ * %-ENODEV if enumeration failed.
31
+ */
32
+int pciehp_configure_device(struct controller *ctrl)
24
33
 {
25
34
 	struct pci_dev *dev;
26
-	struct pci_dev *bridge = p_slot->ctrl->pcie->port;
35
+	struct pci_dev *bridge = ctrl->pcie->port;
27
36
 	struct pci_bus *parent = bridge->subordinate;
28
37
 	int num, ret = 0;
29
-	struct controller *ctrl = p_slot->ctrl;
30
38
 
31
39
 	pci_lock_rescan_remove();
32
40
 
..
..
@@ -55,24 +63,42 @@
55
63
 
56
64
 	pci_assign_unassigned_bridge_resources(bridge);
57
65
 	pcie_bus_configure_settings(parent);
66
+
67
+	/*
68
+	 * Release reset_lock during driver binding
69
+	 * to avoid AB-BA deadlock with device_lock.
70
+	 */
71
+	up_read(&ctrl->reset_lock);
58
72
 	pci_bus_add_devices(parent);
73
+	down_read_nested(&ctrl->reset_lock, ctrl->depth);
59
74
 
60
75
  out:
61
76
 	pci_unlock_rescan_remove();
62
77
 	return ret;
63
78
 }
64
79
 
65
-void pciehp_unconfigure_device(struct slot *p_slot)
80
+/**
81
+ * pciehp_unconfigure_device() - remove PCI devices below a hotplug bridge
82
+ * @ctrl: PCIe hotplug controller
83
+ * @presence: whether the card is still present in the slot;
84
+ *	true for safe removal via sysfs or an Attention Button press,
85
+ *	false for surprise removal
86
+ *
87
+ * Unbind PCI devices below a hotplug bridge from their drivers and remove
88
+ * them from the system.  Safely removed devices are quiesced.  Surprise
89
+ * removed devices are marked as such to prevent further accesses.
90
+ */
91
+void pciehp_unconfigure_device(struct controller *ctrl, bool presence)
66
92
 {
67
-	u8 presence = 0;
68
93
 	struct pci_dev *dev, *temp;
69
-	struct pci_bus *parent = p_slot->ctrl->pcie->port->subordinate;
94
+	struct pci_bus *parent = ctrl->pcie->port->subordinate;
70
95
 	u16 command;
71
-	struct controller *ctrl = p_slot->ctrl;
72
96
 
73
97
 	ctrl_dbg(ctrl, "%s: domain:bus:dev = %04x:%02x:00\n",
74
98
 		 __func__, pci_domain_nr(parent), parent->number);
75
-	pciehp_get_adapter_status(p_slot, &presence);
99
+
100
+	if (!presence)
101
+		pci_walk_bus(parent, pci_dev_set_disconnected, NULL);
76
102
 
77
103
 	pci_lock_rescan_remove();
78
104
 
..
..
@@ -85,13 +111,15 @@
85
111
 	list_for_each_entry_safe_reverse(dev, temp, &parent->devices,
86
112
 					 bus_list) {
87
113
 		pci_dev_get(dev);
88
-		if (!presence) {
89
-			pci_dev_set_disconnected(dev, NULL);
90
-			if (pci_has_subordinate(dev))
91
-				pci_walk_bus(dev->subordinate,
92
-					     pci_dev_set_disconnected, NULL);
93
-		}
114
+
115
+		/*
116
+		 * Release reset_lock during driver unbinding
117
+		 * to avoid AB-BA deadlock with device_lock.
118
+		 */
119
+		up_read(&ctrl->reset_lock);
94
120
 		pci_stop_and_remove_bus_device(dev);
121
+		down_read_nested(&ctrl->reset_lock, ctrl->depth);
122
+
95
123
 		/*
96
124
 		 * Ensure that no new Requests will be generated from
97
125
 		 * the device.