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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/pci/hotplug/pciehp_pci.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/pci/hotplug/pciehp_pci.c')
-rw-r--r--drivers/pci/hotplug/pciehp_pci.c137
1 files changed, 137 insertions, 0 deletions
diff --git a/drivers/pci/hotplug/pciehp_pci.c b/drivers/pci/hotplug/pciehp_pci.c
new file mode 100644
index 000000000..ad12515a4
--- /dev/null
+++ b/drivers/pci/hotplug/pciehp_pci.c
@@ -0,0 +1,137 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * PCI Express Hot Plug Controller Driver
+ *
+ * Copyright (C) 1995,2001 Compaq Computer Corporation
+ * Copyright (C) 2001 Greg Kroah-Hartman (greg@kroah.com)
+ * Copyright (C) 2001 IBM Corp.
+ * Copyright (C) 2003-2004 Intel Corporation
+ *
+ * All rights reserved.
+ *
+ * Send feedback to <greg@kroah.com>, <kristen.c.accardi@intel.com>
+ *
+ */
+
+#define dev_fmt(fmt) "pciehp: " fmt
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/pci.h>
+#include "../pci.h"
+#include "pciehp.h"
+
+/**
+ * pciehp_configure_device() - enumerate PCI devices below a hotplug bridge
+ * @ctrl: PCIe hotplug controller
+ *
+ * Enumerate PCI devices below a hotplug bridge and add them to the system.
+ * Return 0 on success, %-EEXIST if the devices are already enumerated or
+ * %-ENODEV if enumeration failed.
+ */
+int pciehp_configure_device(struct controller *ctrl)
+{
+ struct pci_dev *dev;
+ struct pci_dev *bridge = ctrl->pcie->port;
+ struct pci_bus *parent = bridge->subordinate;
+ int num, ret = 0;
+
+ pci_lock_rescan_remove();
+
+ dev = pci_get_slot(parent, PCI_DEVFN(0, 0));
+ if (dev) {
+ /*
+ * The device is already there. Either configured by the
+ * boot firmware or a previous hotplug event.
+ */
+ ctrl_dbg(ctrl, "Device %s already exists at %04x:%02x:00, skipping hot-add\n",
+ pci_name(dev), pci_domain_nr(parent), parent->number);
+ pci_dev_put(dev);
+ ret = -EEXIST;
+ goto out;
+ }
+
+ num = pci_scan_slot(parent, PCI_DEVFN(0, 0));
+ if (num == 0) {
+ ctrl_err(ctrl, "No new device found\n");
+ ret = -ENODEV;
+ goto out;
+ }
+
+ for_each_pci_bridge(dev, parent)
+ pci_hp_add_bridge(dev);
+
+ pci_assign_unassigned_bridge_resources(bridge);
+ pcie_bus_configure_settings(parent);
+
+ /*
+ * Release reset_lock during driver binding
+ * to avoid AB-BA deadlock with device_lock.
+ */
+ up_read(&ctrl->reset_lock);
+ pci_bus_add_devices(parent);
+ down_read_nested(&ctrl->reset_lock, ctrl->depth);
+
+ out:
+ pci_unlock_rescan_remove();
+ return ret;
+}
+
+/**
+ * pciehp_unconfigure_device() - remove PCI devices below a hotplug bridge
+ * @ctrl: PCIe hotplug controller
+ * @presence: whether the card is still present in the slot;
+ * true for safe removal via sysfs or an Attention Button press,
+ * false for surprise removal
+ *
+ * Unbind PCI devices below a hotplug bridge from their drivers and remove
+ * them from the system. Safely removed devices are quiesced. Surprise
+ * removed devices are marked as such to prevent further accesses.
+ */
+void pciehp_unconfigure_device(struct controller *ctrl, bool presence)
+{
+ struct pci_dev *dev, *temp;
+ struct pci_bus *parent = ctrl->pcie->port->subordinate;
+ u16 command;
+
+ ctrl_dbg(ctrl, "%s: domain:bus:dev = %04x:%02x:00\n",
+ __func__, pci_domain_nr(parent), parent->number);
+
+ if (!presence)
+ pci_walk_bus(parent, pci_dev_set_disconnected, NULL);
+
+ pci_lock_rescan_remove();
+
+ /*
+ * Stopping an SR-IOV PF device removes all the associated VFs,
+ * which will update the bus->devices list and confuse the
+ * iterator. Therefore, iterate in reverse so we remove the VFs
+ * first, then the PF. We do the same in pci_stop_bus_device().
+ */
+ list_for_each_entry_safe_reverse(dev, temp, &parent->devices,
+ bus_list) {
+ pci_dev_get(dev);
+
+ /*
+ * Release reset_lock during driver unbinding
+ * to avoid AB-BA deadlock with device_lock.
+ */
+ up_read(&ctrl->reset_lock);
+ pci_stop_and_remove_bus_device(dev);
+ down_read_nested(&ctrl->reset_lock, ctrl->depth);
+
+ /*
+ * Ensure that no new Requests will be generated from
+ * the device.
+ */
+ if (presence) {
+ pci_read_config_word(dev, PCI_COMMAND, &command);
+ command &= ~(PCI_COMMAND_MASTER | PCI_COMMAND_SERR);
+ command |= PCI_COMMAND_INTX_DISABLE;
+ pci_write_config_word(dev, PCI_COMMAND, command);
+ }
+ pci_dev_put(dev);
+ }
+
+ pci_unlock_rescan_remove();
+}