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path: root/drivers/pci/hotplug/pciehp.h
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Diffstat (limited to 'drivers/pci/hotplug/pciehp.h')
-rw-r--r--drivers/pci/hotplug/pciehp.h117
1 files changed, 91 insertions, 26 deletions
diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h
index 5f892065585e..811cf83f956d 100644
--- a/drivers/pci/hotplug/pciehp.h
+++ b/drivers/pci/hotplug/pciehp.h
@@ -21,6 +21,7 @@
#include <linux/delay.h>
#include <linux/sched/signal.h> /* signal_pending() */
#include <linux/mutex.h>
+#include <linux/rwsem.h>
#include <linux/workqueue.h>
#include "../pcie/portdrv.h"
@@ -57,49 +58,111 @@ do { \
dev_warn(&ctrl->pcie->device, format, ## arg)
#define SLOT_NAME_SIZE 10
+
+/**
+ * struct slot - PCIe hotplug slot
+ * @state: current state machine position
+ * @ctrl: pointer to the slot's controller structure
+ * @hotplug_slot: pointer to the structure registered with the PCI hotplug core
+ * @work: work item to turn the slot on or off after 5 seconds in response to
+ * an Attention Button press
+ * @lock: protects reads and writes of @state;
+ * protects scheduling, execution and cancellation of @work
+ */
struct slot {
u8 state;
struct controller *ctrl;
struct hotplug_slot *hotplug_slot;
- struct delayed_work work; /* work for button event */
+ struct delayed_work work;
struct mutex lock;
- struct mutex hotplug_lock;
- struct workqueue_struct *wq;
-};
-
-struct event_info {
- u32 event_type;
- struct slot *p_slot;
- struct work_struct work;
};
+/**
+ * struct controller - PCIe hotplug controller
+ * @ctrl_lock: serializes writes to the Slot Control register
+ * @pcie: pointer to the controller's PCIe port service device
+ * @reset_lock: prevents access to the Data Link Layer Link Active bit in the
+ * Link Status register and to the Presence Detect State bit in the Slot
+ * Status register during a slot reset which may cause them to flap
+ * @slot: pointer to the controller's slot structure
+ * @queue: wait queue to wake up on reception of a Command Completed event,
+ * used for synchronous writes to the Slot Control register
+ * @slot_cap: cached copy of the Slot Capabilities register
+ * @slot_ctrl: cached copy of the Slot Control register
+ * @poll_thread: thread to poll for slot events if no IRQ is available,
+ * enabled with pciehp_poll_mode module parameter
+ * @cmd_started: jiffies when the Slot Control register was last written;
+ * the next write is allowed 1 second later, absent a Command Completed
+ * interrupt (PCIe r4.0, sec 6.7.3.2)
+ * @cmd_busy: flag set on Slot Control register write, cleared by IRQ handler
+ * on reception of a Command Completed event
+ * @link_active_reporting: cached copy of Data Link Layer Link Active Reporting
+ * Capable bit in Link Capabilities register; if this bit is zero, the
+ * Data Link Layer Link Active bit in the Link Status register will never
+ * be set and the driver is thus confined to wait 1 second before assuming
+ * the link to a hotplugged device is up and accessing it
+ * @notification_enabled: whether the IRQ was requested successfully
+ * @power_fault_detected: whether a power fault was detected by the hardware
+ * that has not yet been cleared by the user
+ * @pending_events: used by the IRQ handler to save events retrieved from the
+ * Slot Status register for later consumption by the IRQ thread
+ * @request_result: result of last user request submitted to the IRQ thread
+ * @requester: wait queue to wake up on completion of user request,
+ * used for synchronous slot enable/disable request via sysfs
+ */
struct controller {
- struct mutex ctrl_lock; /* controller lock */
- struct pcie_device *pcie; /* PCI Express port service */
+ struct mutex ctrl_lock;
+ struct pcie_device *pcie;
+ struct rw_semaphore reset_lock;
struct slot *slot;
- wait_queue_head_t queue; /* sleep & wake process */
+ wait_queue_head_t queue;
u32 slot_cap;
u16 slot_ctrl;
- struct timer_list poll_timer;
+ struct task_struct *poll_thread;
unsigned long cmd_started; /* jiffies */
unsigned int cmd_busy:1;
unsigned int link_active_reporting:1;
unsigned int notification_enabled:1;
unsigned int power_fault_detected;
+ atomic_t pending_events;
+ int request_result;
+ wait_queue_head_t requester;
};
-#define INT_PRESENCE_ON 1
-#define INT_PRESENCE_OFF 2
-#define INT_POWER_FAULT 3
-#define INT_BUTTON_PRESS 4
-#define INT_LINK_UP 5
-#define INT_LINK_DOWN 6
-
-#define STATIC_STATE 0
+/**
+ * DOC: Slot state
+ *
+ * @OFF_STATE: slot is powered off, no subordinate devices are enumerated
+ * @BLINKINGON_STATE: slot will be powered on after the 5 second delay,
+ * green led is blinking
+ * @BLINKINGOFF_STATE: slot will be powered off after the 5 second delay,
+ * green led is blinking
+ * @POWERON_STATE: slot is currently powering on
+ * @POWEROFF_STATE: slot is currently powering off
+ * @ON_STATE: slot is powered on, subordinate devices have been enumerated
+ */
+#define OFF_STATE 0
#define BLINKINGON_STATE 1
#define BLINKINGOFF_STATE 2
#define POWERON_STATE 3
#define POWEROFF_STATE 4
+#define ON_STATE 5
+
+/**
+ * DOC: Flags to request an action from the IRQ thread
+ *
+ * These are stored together with events read from the Slot Status register,
+ * hence must be greater than its 16-bit width.
+ *
+ * %DISABLE_SLOT: Disable the slot in response to a user request via sysfs or
+ * an Attention Button press after the 5 second delay
+ * %RERUN_ISR: Used by the IRQ handler to inform the IRQ thread that the
+ * hotplug port was inaccessible when the interrupt occurred, requiring
+ * that the IRQ handler is rerun by the IRQ thread after it has made the
+ * hotplug port accessible by runtime resuming its parents to D0
+ */
+#define DISABLE_SLOT (1 << 16)
+#define RERUN_ISR (1 << 17)
#define ATTN_BUTTN(ctrl) ((ctrl)->slot_cap & PCI_EXP_SLTCAP_ABP)
#define POWER_CTRL(ctrl) ((ctrl)->slot_cap & PCI_EXP_SLTCAP_PCP)
@@ -113,15 +176,17 @@ struct controller {
int pciehp_sysfs_enable_slot(struct slot *slot);
int pciehp_sysfs_disable_slot(struct slot *slot);
-void pciehp_queue_interrupt_event(struct slot *slot, u32 event_type);
+void pciehp_request(struct controller *ctrl, int action);
+void pciehp_handle_button_press(struct slot *slot);
+void pciehp_handle_disable_request(struct slot *slot);
+void pciehp_handle_presence_or_link_change(struct slot *slot, u32 events);
int pciehp_configure_device(struct slot *p_slot);
-int pciehp_unconfigure_device(struct slot *p_slot);
+void pciehp_unconfigure_device(struct slot *p_slot);
void pciehp_queue_pushbutton_work(struct work_struct *work);
struct controller *pcie_init(struct pcie_device *dev);
int pcie_init_notification(struct controller *ctrl);
-int pciehp_enable_slot(struct slot *p_slot);
-int pciehp_disable_slot(struct slot *p_slot);
-void pcie_reenable_notification(struct controller *ctrl);
+void pcie_shutdown_notification(struct controller *ctrl);
+void pcie_clear_hotplug_events(struct controller *ctrl);
int pciehp_power_on_slot(struct slot *slot);
void pciehp_power_off_slot(struct slot *slot);
void pciehp_get_power_status(struct slot *slot, u8 *status);