diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h index 7fb326983ed6..541bbe6d5343 100644 --- a/drivers/pci/hotplug/pciehp.h +++ b/drivers/pci/hotplug/pciehp.h @@ -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) { diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c index 7d72c5e2eba9..f4a18f51a29c 100644 --- a/drivers/pci/hotplug/pciehp_core.c +++ b/drivers/pci/hotplug/pciehp_core.c @@ -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; diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c index b2255736ac81..51f56ef4ab6f 100644 --- a/drivers/pci/hotplug/pciehp_hpc.c +++ b/drivers/pci/hotplug/pciehp_hpc.c @@ -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)) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 7d6ce2ec04ec..10e3c4e15178 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -22,6 +22,7 @@ #include #include #include +#include #include #include #include "pci.h" @@ -3288,9 +3289,42 @@ static int pci_pm_reset(struct pci_dev *dev, int probe) return 0; } -static int pci_parent_bus_reset(struct pci_dev *dev, int probe) +/** + * pci_reset_bridge_secondary_bus - Reset the secondary bus on a PCI bridge. + * @dev: Bridge device + * + * Use the bridge control register to assert reset on the secondary bus. + * Devices on the secondary bus are left in power-on state. + */ +void pci_reset_bridge_secondary_bus(struct pci_dev *dev) { u16 ctrl; + + pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &ctrl); + ctrl |= PCI_BRIDGE_CTL_BUS_RESET; + pci_write_config_word(dev, PCI_BRIDGE_CONTROL, ctrl); + /* + * PCI spec v3.0 7.6.4.2 requires minimum Trst of 1ms. Double + * this to 2ms to ensure that we meet the minium requirement. + */ + msleep(2); + + ctrl &= ~PCI_BRIDGE_CTL_BUS_RESET; + pci_write_config_word(dev, PCI_BRIDGE_CONTROL, ctrl); + + /* + * Trhfa for conventional PCI is 2^25 clock cycles. + * Assuming a minimum 33MHz clock this results in a 1s + * delay before we can consider subordinate devices to + * be re-initialized. PCIe has some ways to shorten this, + * but we don't make use of them yet. + */ + ssleep(1); +} +EXPORT_SYMBOL_GPL(pci_reset_bridge_secondary_bus); + +static int pci_parent_bus_reset(struct pci_dev *dev, int probe) +{ struct pci_dev *pdev; if (pci_is_root_bus(dev->bus) || dev->subordinate || !dev->bus->self) @@ -3303,18 +3337,40 @@ static int pci_parent_bus_reset(struct pci_dev *dev, int probe) if (probe) return 0; - pci_read_config_word(dev->bus->self, PCI_BRIDGE_CONTROL, &ctrl); - ctrl |= PCI_BRIDGE_CTL_BUS_RESET; - pci_write_config_word(dev->bus->self, PCI_BRIDGE_CONTROL, ctrl); - msleep(100); - - ctrl &= ~PCI_BRIDGE_CTL_BUS_RESET; - pci_write_config_word(dev->bus->self, PCI_BRIDGE_CONTROL, ctrl); - msleep(100); + pci_reset_bridge_secondary_bus(dev->bus->self); return 0; } +static int pci_reset_hotplug_slot(struct hotplug_slot *hotplug, int probe) +{ + int rc = -ENOTTY; + + if (!hotplug || !try_module_get(hotplug->ops->owner)) + return rc; + + if (hotplug->ops->reset_slot) + rc = hotplug->ops->reset_slot(hotplug, probe); + + module_put(hotplug->ops->owner); + + return rc; +} + +static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe) +{ + struct pci_dev *pdev; + + if (dev->subordinate || !dev->slot) + return -ENOTTY; + + list_for_each_entry(pdev, &dev->bus->devices, bus_list) + if (pdev != dev && pdev->slot == dev->slot) + return -ENOTTY; + + return pci_reset_hotplug_slot(dev->slot->hotplug, probe); +} + static int __pci_dev_reset(struct pci_dev *dev, int probe) { int rc; @@ -3337,27 +3393,65 @@ static int __pci_dev_reset(struct pci_dev *dev, int probe) if (rc != -ENOTTY) goto done; + rc = pci_dev_reset_slot_function(dev, probe); + if (rc != -ENOTTY) + goto done; + rc = pci_parent_bus_reset(dev, probe); done: return rc; } +static void pci_dev_lock(struct pci_dev *dev) +{ + pci_cfg_access_lock(dev); + /* block PM suspend, driver probe, etc. */ + device_lock(&dev->dev); +} + +static void pci_dev_unlock(struct pci_dev *dev) +{ + device_unlock(&dev->dev); + pci_cfg_access_unlock(dev); +} + +static void pci_dev_save_and_disable(struct pci_dev *dev) +{ + /* + * Wake-up device prior to save. PM registers default to D0 after + * reset and a simple register restore doesn't reliably return + * to a non-D0 state anyway. + */ + pci_set_power_state(dev, PCI_D0); + + pci_save_state(dev); + /* + * Disable the device by clearing the Command register, except for + * INTx-disable which is set. This not only disables MMIO and I/O port + * BARs, but also prevents the device from being Bus Master, preventing + * DMA from the device including MSI/MSI-X interrupts. For PCI 2.3 + * compliant devices, INTx-disable prevents legacy interrupts. + */ + pci_write_config_word(dev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE); +} + +static void pci_dev_restore(struct pci_dev *dev) +{ + pci_restore_state(dev); +} + static int pci_dev_reset(struct pci_dev *dev, int probe) { int rc; - if (!probe) { - pci_cfg_access_lock(dev); - /* block PM suspend, driver probe, etc. */ - device_lock(&dev->dev); - } + if (!probe) + pci_dev_lock(dev); rc = __pci_dev_reset(dev, probe); - if (!probe) { - device_unlock(&dev->dev); - pci_cfg_access_unlock(dev); - } + if (!probe) + pci_dev_unlock(dev); + return rc; } /** @@ -3448,22 +3542,249 @@ int pci_reset_function(struct pci_dev *dev) if (rc) return rc; - pci_save_state(dev); - - /* - * both INTx and MSI are disabled after the Interrupt Disable bit - * is set and the Bus Master bit is cleared. - */ - pci_write_config_word(dev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE); + pci_dev_save_and_disable(dev); rc = pci_dev_reset(dev, 0); - pci_restore_state(dev); + pci_dev_restore(dev); return rc; } EXPORT_SYMBOL_GPL(pci_reset_function); +/* Lock devices from the top of the tree down */ +static void pci_bus_lock(struct pci_bus *bus) +{ + struct pci_dev *dev; + + list_for_each_entry(dev, &bus->devices, bus_list) { + pci_dev_lock(dev); + if (dev->subordinate) + pci_bus_lock(dev->subordinate); + } +} + +/* Unlock devices from the bottom of the tree up */ +static void pci_bus_unlock(struct pci_bus *bus) +{ + struct pci_dev *dev; + + list_for_each_entry(dev, &bus->devices, bus_list) { + if (dev->subordinate) + pci_bus_unlock(dev->subordinate); + pci_dev_unlock(dev); + } +} + +/* Lock devices from the top of the tree down */ +static void pci_slot_lock(struct pci_slot *slot) +{ + struct pci_dev *dev; + + list_for_each_entry(dev, &slot->bus->devices, bus_list) { + if (!dev->slot || dev->slot != slot) + continue; + pci_dev_lock(dev); + if (dev->subordinate) + pci_bus_lock(dev->subordinate); + } +} + +/* Unlock devices from the bottom of the tree up */ +static void pci_slot_unlock(struct pci_slot *slot) +{ + struct pci_dev *dev; + + list_for_each_entry(dev, &slot->bus->devices, bus_list) { + if (!dev->slot || dev->slot != slot) + continue; + if (dev->subordinate) + pci_bus_unlock(dev->subordinate); + pci_dev_unlock(dev); + } +} + +/* Save and disable devices from the top of the tree down */ +static void pci_bus_save_and_disable(struct pci_bus *bus) +{ + struct pci_dev *dev; + + list_for_each_entry(dev, &bus->devices, bus_list) { + pci_dev_save_and_disable(dev); + if (dev->subordinate) + pci_bus_save_and_disable(dev->subordinate); + } +} + +/* + * Restore devices from top of the tree down - parent bridges need to be + * restored before we can get to subordinate devices. + */ +static void pci_bus_restore(struct pci_bus *bus) +{ + struct pci_dev *dev; + + list_for_each_entry(dev, &bus->devices, bus_list) { + pci_dev_restore(dev); + if (dev->subordinate) + pci_bus_restore(dev->subordinate); + } +} + +/* Save and disable devices from the top of the tree down */ +static void pci_slot_save_and_disable(struct pci_slot *slot) +{ + struct pci_dev *dev; + + list_for_each_entry(dev, &slot->bus->devices, bus_list) { + if (!dev->slot || dev->slot != slot) + continue; + pci_dev_save_and_disable(dev); + if (dev->subordinate) + pci_bus_save_and_disable(dev->subordinate); + } +} + +/* + * Restore devices from top of the tree down - parent bridges need to be + * restored before we can get to subordinate devices. + */ +static void pci_slot_restore(struct pci_slot *slot) +{ + struct pci_dev *dev; + + list_for_each_entry(dev, &slot->bus->devices, bus_list) { + if (!dev->slot || dev->slot != slot) + continue; + pci_dev_restore(dev); + if (dev->subordinate) + pci_bus_restore(dev->subordinate); + } +} + +static int pci_slot_reset(struct pci_slot *slot, int probe) +{ + int rc; + + if (!slot) + return -ENOTTY; + + if (!probe) + pci_slot_lock(slot); + + might_sleep(); + + rc = pci_reset_hotplug_slot(slot->hotplug, probe); + + if (!probe) + pci_slot_unlock(slot); + + return rc; +} + +/** + * pci_probe_reset_slot - probe whether a PCI slot can be reset + * @slot: PCI slot to probe + * + * Return 0 if slot can be reset, negative if a slot reset is not supported. + */ +int pci_probe_reset_slot(struct pci_slot *slot) +{ + return pci_slot_reset(slot, 1); +} +EXPORT_SYMBOL_GPL(pci_probe_reset_slot); + +/** + * pci_reset_slot - reset a PCI slot + * @slot: PCI slot to reset + * + * A PCI bus may host multiple slots, each slot may support a reset mechanism + * independent of other slots. For instance, some slots may support slot power + * control. In the case of a 1:1 bus to slot architecture, this function may + * wrap the bus reset to avoid spurious slot related events such as hotplug. + * Generally a slot reset should be attempted before a bus reset. All of the + * function of the slot and any subordinate buses behind the slot are reset + * through this function. PCI config space of all devices in the slot and + * behind the slot is saved before and restored after reset. + * + * Return 0 on success, non-zero on error. + */ +int pci_reset_slot(struct pci_slot *slot) +{ + int rc; + + rc = pci_slot_reset(slot, 1); + if (rc) + return rc; + + pci_slot_save_and_disable(slot); + + rc = pci_slot_reset(slot, 0); + + pci_slot_restore(slot); + + return rc; +} +EXPORT_SYMBOL_GPL(pci_reset_slot); + +static int pci_bus_reset(struct pci_bus *bus, int probe) +{ + if (!bus->self) + return -ENOTTY; + + if (probe) + return 0; + + pci_bus_lock(bus); + + might_sleep(); + + pci_reset_bridge_secondary_bus(bus->self); + + pci_bus_unlock(bus); + + return 0; +} + +/** + * pci_probe_reset_bus - probe whether a PCI bus can be reset + * @bus: PCI bus to probe + * + * Return 0 if bus can be reset, negative if a bus reset is not supported. + */ +int pci_probe_reset_bus(struct pci_bus *bus) +{ + return pci_bus_reset(bus, 1); +} +EXPORT_SYMBOL_GPL(pci_probe_reset_bus); + +/** + * pci_reset_bus - reset a PCI bus + * @bus: top level PCI bus to reset + * + * Do a bus reset on the given bus and any subordinate buses, saving + * and restoring state of all devices. + * + * Return 0 on success, non-zero on error. + */ +int pci_reset_bus(struct pci_bus *bus) +{ + int rc; + + rc = pci_bus_reset(bus, 1); + if (rc) + return rc; + + pci_bus_save_and_disable(bus); + + rc = pci_bus_reset(bus, 0); + + pci_bus_restore(bus); + + return rc; +} +EXPORT_SYMBOL_GPL(pci_reset_bus); + /** * pcix_get_max_mmrbc - get PCI-X maximum designed memory read byte count * @dev: PCI device to query diff --git a/drivers/pci/pcie/aer/aerdrv.c b/drivers/pci/pcie/aer/aerdrv.c index 76ef634caf6f..0bf82a20a0fb 100644 --- a/drivers/pci/pcie/aer/aerdrv.c +++ b/drivers/pci/pcie/aer/aerdrv.c @@ -352,7 +352,7 @@ static pci_ers_result_t aer_root_reset(struct pci_dev *dev) reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK; pci_write_config_dword(dev, pos + PCI_ERR_ROOT_COMMAND, reg32); - aer_do_secondary_bus_reset(dev); + pci_reset_bridge_secondary_bus(dev); dev_printk(KERN_DEBUG, &dev->dev, "Root Port link has been reset\n"); /* Clear Root Error Status */ diff --git a/drivers/pci/pcie/aer/aerdrv.h b/drivers/pci/pcie/aer/aerdrv.h index 90ea3e88041f..84420b7c9456 100644 --- a/drivers/pci/pcie/aer/aerdrv.h +++ b/drivers/pci/pcie/aer/aerdrv.h @@ -106,7 +106,6 @@ static inline pci_ers_result_t merge_result(enum pci_ers_result orig, } extern struct bus_type pcie_port_bus_type; -void aer_do_secondary_bus_reset(struct pci_dev *dev); int aer_init(struct pcie_device *dev); void aer_isr(struct work_struct *work); void aer_print_error(struct pci_dev *dev, struct aer_err_info *info); diff --git a/drivers/pci/pcie/aer/aerdrv_core.c b/drivers/pci/pcie/aer/aerdrv_core.c index 8b68ae59b7b6..85ca36f2136d 100644 --- a/drivers/pci/pcie/aer/aerdrv_core.c +++ b/drivers/pci/pcie/aer/aerdrv_core.c @@ -366,39 +366,6 @@ static pci_ers_result_t broadcast_error_message(struct pci_dev *dev, return result_data.result; } -/** - * aer_do_secondary_bus_reset - perform secondary bus reset - * @dev: pointer to bridge's pci_dev data structure - * - * Invoked when performing link reset at Root Port or Downstream Port. - */ -void aer_do_secondary_bus_reset(struct pci_dev *dev) -{ - u16 p2p_ctrl; - - /* Assert Secondary Bus Reset */ - pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &p2p_ctrl); - p2p_ctrl |= PCI_BRIDGE_CTL_BUS_RESET; - pci_write_config_word(dev, PCI_BRIDGE_CONTROL, p2p_ctrl); - - /* - * we should send hot reset message for 2ms to allow it time to - * propagate to all downstream ports - */ - msleep(2); - - /* De-assert Secondary Bus Reset */ - p2p_ctrl &= ~PCI_BRIDGE_CTL_BUS_RESET; - pci_write_config_word(dev, PCI_BRIDGE_CONTROL, p2p_ctrl); - - /* - * System software must wait for at least 100ms from the end - * of a reset of one or more device before it is permitted - * to issue Configuration Requests to those devices. - */ - msleep(200); -} - /** * default_reset_link - default reset function * @dev: pointer to pci_dev data structure @@ -408,7 +375,7 @@ void aer_do_secondary_bus_reset(struct pci_dev *dev) */ static pci_ers_result_t default_reset_link(struct pci_dev *dev) { - aer_do_secondary_bus_reset(dev); + pci_reset_bridge_secondary_bus(dev); dev_printk(KERN_DEBUG, &dev->dev, "downstream link has been reset\n"); return PCI_ERS_RESULT_RECOVERED; } diff --git a/include/linux/pci.h b/include/linux/pci.h index e6470016c718..408f047ad929 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -925,6 +925,11 @@ int pcie_set_mps(struct pci_dev *dev, int mps); int __pci_reset_function(struct pci_dev *dev); int __pci_reset_function_locked(struct pci_dev *dev); int pci_reset_function(struct pci_dev *dev); +int pci_probe_reset_slot(struct pci_slot *slot); +int pci_reset_slot(struct pci_slot *slot); +int pci_probe_reset_bus(struct pci_bus *bus); +int pci_reset_bus(struct pci_bus *bus); +void pci_reset_bridge_secondary_bus(struct pci_dev *dev); void pci_update_resource(struct pci_dev *dev, int resno); int __must_check pci_assign_resource(struct pci_dev *dev, int i); int __must_check pci_reassign_resource(struct pci_dev *dev, int i, resource_size_t add_size, resource_size_t align); diff --git a/include/linux/pci_hotplug.h b/include/linux/pci_hotplug.h index 8db71dcd6337..bd32109e607e 100644 --- a/include/linux/pci_hotplug.h +++ b/include/linux/pci_hotplug.h @@ -63,6 +63,9 @@ enum pcie_link_width { * @get_adapter_status: Called to get see if an adapter is present in the slot or not. * If this field is NULL, the value passed in the struct hotplug_slot_info * will be used when this value is requested by a user. + * @reset_slot: Optional interface to allow override of a bus reset for the + * slot for cases where a secondary bus reset can result in spurious + * hotplug events or where a slot can be reset independent of the bus. * * The table of function pointers that is passed to the hotplug pci core by a * hotplug pci driver. These functions are called by the hotplug pci core when @@ -80,6 +83,7 @@ struct hotplug_slot_ops { int (*get_attention_status) (struct hotplug_slot *slot, u8 *value); int (*get_latch_status) (struct hotplug_slot *slot, u8 *value); int (*get_adapter_status) (struct hotplug_slot *slot, u8 *value); + int (*reset_slot) (struct hotplug_slot *slot, int probe); }; /**