Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754798Ab3HETh3 (ORCPT ); Mon, 5 Aug 2013 15:37:29 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42220 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754601Ab3HETh0 (ORCPT ); Mon, 5 Aug 2013 15:37:26 -0400 Subject: [PATCH v4 3/9] pci: Implement reset_slot for pciehp To: bhelgaas@google.com, linux-pci@vger.kernel.org From: Alex Williamson Cc: ddutile@redhat.com, indou.takao@jp.fujitsu.com, linux-kernel@vger.kernel.org Date: Mon, 05 Aug 2013 13:37:22 -0600 Message-ID: <20130805193722.9260.10216.stgit@bling.home> In-Reply-To: <20130805193200.9260.38729.stgit@bling.home> References: <20130805193200.9260.38729.stgit@bling.home> User-Agent: StGit/0.16 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4018 Lines: 110 PCIe hotplug has a bus per slot, so we can just use a normal secondary bus reset. However, if a slot supports surprise removal then 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 --- drivers/pci/hotplug/pciehp.h | 1 + drivers/pci/hotplug/pciehp_core.c | 12 ++++++++++++ drivers/pci/hotplug/pciehp_hpc.c | 31 +++++++++++++++++++++++++++++++ 3 files changed, 44 insertions(+) diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h index 7fb3269..541bbe6 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 7d72c5e..f4a18f5 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 b225573..51f56ef 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)) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/