PCI: pciehp: Add reset_slot() method

PCIe hotplug has a bus per slot, so we can just use a normal
secondary bus reset.  However, if a slot supports surprise removal,
a bus reset can be seen as a presence detection change triggering
a hot-remove followed by a hot-add.  Disable presence detection from
triggering an interrupt or being polled around the bus reset.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
This commit is contained in:
Alex Williamson 2013-08-08 14:09:37 -06:00 committed by Bjorn Helgaas
parent 5c32b35b00
commit 2e35afaefe
3 changed files with 44 additions and 0 deletions

View file

@ -155,6 +155,7 @@ void pciehp_green_led_off(struct slot *slot);
void pciehp_green_led_blink(struct slot *slot);
int pciehp_check_link_status(struct controller *ctrl);
void pciehp_release_ctrl(struct controller *ctrl);
int pciehp_reset_slot(struct slot *slot, int probe);
static inline const char *slot_name(struct slot *slot)
{

View file

@ -69,6 +69,7 @@ static int get_power_status (struct hotplug_slot *slot, u8 *value);
static int get_attention_status (struct hotplug_slot *slot, u8 *value);
static int get_latch_status (struct hotplug_slot *slot, u8 *value);
static int get_adapter_status (struct hotplug_slot *slot, u8 *value);
static int reset_slot (struct hotplug_slot *slot, int probe);
/**
* release_slot - free up the memory used by a slot
@ -111,6 +112,7 @@ static int init_slot(struct controller *ctrl)
ops->disable_slot = disable_slot;
ops->get_power_status = get_power_status;
ops->get_adapter_status = get_adapter_status;
ops->reset_slot = reset_slot;
if (MRL_SENS(ctrl))
ops->get_latch_status = get_latch_status;
if (ATTN_LED(ctrl)) {
@ -223,6 +225,16 @@ static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
return pciehp_get_adapter_status(slot, value);
}
static int reset_slot(struct hotplug_slot *hotplug_slot, int probe)
{
struct slot *slot = hotplug_slot->private;
ctrl_dbg(slot->ctrl, "%s: physical_slot = %s\n",
__func__, slot_name(slot));
return pciehp_reset_slot(slot, probe);
}
static int pciehp_probe(struct pcie_device *dev)
{
int rc;

View file

@ -749,6 +749,37 @@ static void pcie_disable_notification(struct controller *ctrl)
ctrl_warn(ctrl, "Cannot disable software notification\n");
}
/*
* pciehp has a 1:1 bus:slot relationship so we ultimately want a secondary
* bus reset of the bridge, but if the slot supports surprise removal we need
* to disable presence detection around the bus reset and clear any spurious
* events after.
*/
int pciehp_reset_slot(struct slot *slot, int probe)
{
struct controller *ctrl = slot->ctrl;
if (probe)
return 0;
if (HP_SUPR_RM(ctrl)) {
pcie_write_cmd(ctrl, 0, PCI_EXP_SLTCTL_PDCE);
if (pciehp_poll_mode)
del_timer_sync(&ctrl->poll_timer);
}
pci_reset_bridge_secondary_bus(ctrl->pcie->port);
if (HP_SUPR_RM(ctrl)) {
pciehp_writew(ctrl, PCI_EXP_SLTSTA, PCI_EXP_SLTSTA_PDC);
pcie_write_cmd(ctrl, PCI_EXP_SLTCTL_PDCE, PCI_EXP_SLTCTL_PDCE);
if (pciehp_poll_mode)
int_poll_timeout(ctrl->poll_timer.data);
}
return 0;
}
int pcie_init_notification(struct controller *ctrl)
{
if (pciehp_request_irq(ctrl))