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![Lukas Wunner](/assets/img/avatar_default.png)
When a hotplug driver calls pci_hp_register(), all steps necessary for registration are carried out in one go, including creation of a kobject and addition to sysfs. That's a problem for pciehp once it's converted to enable/disable the slot exclusively from the IRQ thread: The thread needs to be spawned after creation of the kobject (because it uses the kobject's name), but before addition to sysfs (because it will handle enable/disable requests submitted via sysfs). pci_hp_deregister() does offer a ->release callback that's invoked after deletion from sysfs and before destruction of the kobject. But because pci_hp_register() doesn't offer a counterpart, hotplug drivers' ->probe and ->remove code becomes asymmetric, which is error prone as recently discovered use-after-free bugs in pciehp's ->remove hook have shown. In a sense, this appears to be a case of the midlayer antipattern: "The core thesis of the "midlayer mistake" is that midlayers are bad and should not exist. That common functionality which it is so tempting to put in a midlayer should instead be provided as library routines which can [be] used, augmented, or ignored by each bottom level driver independently. Thus every subsystem that supports multiple implementations (or drivers) should provide a very thin top layer which calls directly into the bottom layer drivers, and a rich library of support code that eases the implementation of those drivers. This library is available to, but not forced upon, those drivers." -- Neil Brown (2009), https://lwn.net/Articles/336262/ The presence of midlayer traits in the PCI hotplug core might be ascribed to its age: When it was introduced in February 2002, the blessings of a library approach might not have been well known: https://git.kernel.org/tglx/history/c/a8a2069f432c For comparison, the driver core does offer split functions for creating a kobject (device_initialize()) and addition to sysfs (device_add()) as an alternative to carrying out everything at once (device_register()). This was introduced in October 2002: https://git.kernel.org/tglx/history/c/8b290eb19962 The odd ->release callback in the PCI hotplug core was added in 2003: https://git.kernel.org/tglx/history/c/69f8d663b595 Clearly, a library approach would not force every hotplug driver to implement a ->release callback, but rather allow the driver to remove the sysfs files, release its data structures and finally destroy the kobject. Alternatively, a driver may choose to remove everything with pci_hp_deregister(), then release its data structures. To this end, offer drivers pci_hp_initialize() and pci_hp_add() as a split-up version of pci_hp_register(). Likewise, offer pci_hp_del() and pci_hp_destroy() as a split-up version of pci_hp_deregister(). Eliminate the ->release callback and move its code into each driver's teardown routine. Declare pci_hp_deregister() void, in keeping with the usual kernel pattern that enablement can fail, but disablement cannot. It only returned an error if the caller passed in a NULL pointer or a slot which has never or is no longer registered or is sharing its name with another slot. Those would be bugs, so WARN about them. Few hotplug drivers actually checked the return value and those that did only printed a useless error message to dmesg. Remove that. For most drivers the conversion was straightforward since it doesn't matter whether the code in the ->release callback is executed before or after destruction of the kobject. But in the case of ibmphp, it was unclear to me whether setting slot_cur->ctrl and slot_cur->bus_on to NULL needs to happen before the kobject is destroyed, so I erred on the side of caution and ensured that the order stays the same. Another nontrivial case is pnv_php, I've found the list and kref logic difficult to understand, however my impression was that it is safe to delete the list element and drop the references until after the kobject is destroyed. Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com> # drivers/platform/x86 Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Len Brown <lenb@kernel.org> Cc: Scott Murray <scott@spiteful.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Gavin Shan <gwshan@linux.vnet.ibm.com> Cc: Sebastian Ott <sebott@linux.vnet.ibm.com> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Cc: Corentin Chary <corentin.chary@gmail.com> Cc: Darren Hart <dvhart@infradead.org> Cc: Andy Shevchenko <andy@infradead.org>
965 lines
23 KiB
C
965 lines
23 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* PCI Hotplug Driver for PowerPC PowerNV platform.
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*
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* Copyright Gavin Shan, IBM Corporation 2016.
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*/
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#include <linux/libfdt.h>
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#include <linux/module.h>
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#include <linux/pci.h>
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#include <linux/pci_hotplug.h>
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#include <asm/opal.h>
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#include <asm/pnv-pci.h>
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#include <asm/ppc-pci.h>
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#define DRIVER_VERSION "0.1"
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#define DRIVER_AUTHOR "Gavin Shan, IBM Corporation"
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#define DRIVER_DESC "PowerPC PowerNV PCI Hotplug Driver"
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struct pnv_php_event {
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bool added;
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struct pnv_php_slot *php_slot;
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struct work_struct work;
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};
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static LIST_HEAD(pnv_php_slot_list);
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static DEFINE_SPINLOCK(pnv_php_lock);
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static void pnv_php_register(struct device_node *dn);
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static void pnv_php_unregister_one(struct device_node *dn);
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static void pnv_php_unregister(struct device_node *dn);
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static void pnv_php_disable_irq(struct pnv_php_slot *php_slot,
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bool disable_device)
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{
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struct pci_dev *pdev = php_slot->pdev;
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int irq = php_slot->irq;
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u16 ctrl;
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if (php_slot->irq > 0) {
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pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &ctrl);
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ctrl &= ~(PCI_EXP_SLTCTL_HPIE |
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PCI_EXP_SLTCTL_PDCE |
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PCI_EXP_SLTCTL_DLLSCE);
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pcie_capability_write_word(pdev, PCI_EXP_SLTCTL, ctrl);
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free_irq(php_slot->irq, php_slot);
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php_slot->irq = 0;
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}
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if (php_slot->wq) {
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destroy_workqueue(php_slot->wq);
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php_slot->wq = NULL;
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}
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if (disable_device || irq > 0) {
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if (pdev->msix_enabled)
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pci_disable_msix(pdev);
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else if (pdev->msi_enabled)
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pci_disable_msi(pdev);
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pci_disable_device(pdev);
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}
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}
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static void pnv_php_free_slot(struct kref *kref)
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{
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struct pnv_php_slot *php_slot = container_of(kref,
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struct pnv_php_slot, kref);
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WARN_ON(!list_empty(&php_slot->children));
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pnv_php_disable_irq(php_slot, false);
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kfree(php_slot->name);
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kfree(php_slot);
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}
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static inline void pnv_php_put_slot(struct pnv_php_slot *php_slot)
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{
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if (!php_slot)
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return;
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kref_put(&php_slot->kref, pnv_php_free_slot);
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}
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static struct pnv_php_slot *pnv_php_match(struct device_node *dn,
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struct pnv_php_slot *php_slot)
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{
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struct pnv_php_slot *target, *tmp;
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if (php_slot->dn == dn) {
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kref_get(&php_slot->kref);
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return php_slot;
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}
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list_for_each_entry(tmp, &php_slot->children, link) {
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target = pnv_php_match(dn, tmp);
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if (target)
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return target;
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}
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return NULL;
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}
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struct pnv_php_slot *pnv_php_find_slot(struct device_node *dn)
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{
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struct pnv_php_slot *php_slot, *tmp;
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unsigned long flags;
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spin_lock_irqsave(&pnv_php_lock, flags);
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list_for_each_entry(tmp, &pnv_php_slot_list, link) {
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php_slot = pnv_php_match(dn, tmp);
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if (php_slot) {
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spin_unlock_irqrestore(&pnv_php_lock, flags);
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return php_slot;
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}
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}
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spin_unlock_irqrestore(&pnv_php_lock, flags);
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return NULL;
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}
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EXPORT_SYMBOL_GPL(pnv_php_find_slot);
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/*
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* Remove pdn for all children of the indicated device node.
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* The function should remove pdn in a depth-first manner.
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*/
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static void pnv_php_rmv_pdns(struct device_node *dn)
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{
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struct device_node *child;
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for_each_child_of_node(dn, child) {
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pnv_php_rmv_pdns(child);
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pci_remove_device_node_info(child);
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}
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}
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/*
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* Detach all child nodes of the indicated device nodes. The
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* function should handle device nodes in depth-first manner.
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*
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* We should not invoke of_node_release() as the memory for
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* individual device node is part of large memory block. The
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* large block is allocated from memblock (system bootup) or
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* kmalloc() when unflattening the device tree by OF changeset.
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* We can not free the large block allocated from memblock. For
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* later case, it should be released at once.
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*/
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static void pnv_php_detach_device_nodes(struct device_node *parent)
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{
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struct device_node *dn;
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int refcount;
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for_each_child_of_node(parent, dn) {
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pnv_php_detach_device_nodes(dn);
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of_node_put(dn);
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refcount = kref_read(&dn->kobj.kref);
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if (refcount != 1)
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pr_warn("Invalid refcount %d on <%pOF>\n",
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refcount, dn);
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of_detach_node(dn);
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}
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}
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static void pnv_php_rmv_devtree(struct pnv_php_slot *php_slot)
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{
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pnv_php_rmv_pdns(php_slot->dn);
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/*
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* Decrease the refcount if the device nodes were created
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* through OF changeset before detaching them.
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*/
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if (php_slot->fdt)
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of_changeset_destroy(&php_slot->ocs);
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pnv_php_detach_device_nodes(php_slot->dn);
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if (php_slot->fdt) {
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kfree(php_slot->dt);
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kfree(php_slot->fdt);
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php_slot->dt = NULL;
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php_slot->dn->child = NULL;
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php_slot->fdt = NULL;
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}
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}
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/*
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* As the nodes in OF changeset are applied in reverse order, we
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* need revert the nodes in advance so that we have correct node
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* order after the changeset is applied.
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*/
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static void pnv_php_reverse_nodes(struct device_node *parent)
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{
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struct device_node *child, *next;
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/* In-depth first */
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for_each_child_of_node(parent, child)
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pnv_php_reverse_nodes(child);
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/* Reverse the nodes in the child list */
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child = parent->child;
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parent->child = NULL;
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while (child) {
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next = child->sibling;
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child->sibling = parent->child;
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parent->child = child;
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child = next;
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}
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}
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static int pnv_php_populate_changeset(struct of_changeset *ocs,
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struct device_node *dn)
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{
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struct device_node *child;
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int ret = 0;
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for_each_child_of_node(dn, child) {
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ret = of_changeset_attach_node(ocs, child);
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if (ret) {
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of_node_put(child);
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break;
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}
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ret = pnv_php_populate_changeset(ocs, child);
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if (ret) {
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of_node_put(child);
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break;
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}
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}
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return ret;
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}
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static void *pnv_php_add_one_pdn(struct device_node *dn, void *data)
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{
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struct pci_controller *hose = (struct pci_controller *)data;
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struct pci_dn *pdn;
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pdn = pci_add_device_node_info(hose, dn);
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if (!pdn)
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return ERR_PTR(-ENOMEM);
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return NULL;
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}
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static void pnv_php_add_pdns(struct pnv_php_slot *slot)
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{
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struct pci_controller *hose = pci_bus_to_host(slot->bus);
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pci_traverse_device_nodes(slot->dn, pnv_php_add_one_pdn, hose);
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}
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static int pnv_php_add_devtree(struct pnv_php_slot *php_slot)
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{
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void *fdt, *fdt1, *dt;
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int ret;
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/* We don't know the FDT blob size. We try to get it through
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* maximal memory chunk and then copy it to another chunk that
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* fits the real size.
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*/
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fdt1 = kzalloc(0x10000, GFP_KERNEL);
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if (!fdt1) {
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ret = -ENOMEM;
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goto out;
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}
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ret = pnv_pci_get_device_tree(php_slot->dn->phandle, fdt1, 0x10000);
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if (ret) {
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pci_warn(php_slot->pdev, "Error %d getting FDT blob\n", ret);
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goto free_fdt1;
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}
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fdt = kzalloc(fdt_totalsize(fdt1), GFP_KERNEL);
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if (!fdt) {
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ret = -ENOMEM;
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goto free_fdt1;
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}
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/* Unflatten device tree blob */
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memcpy(fdt, fdt1, fdt_totalsize(fdt1));
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dt = of_fdt_unflatten_tree(fdt, php_slot->dn, NULL);
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if (!dt) {
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ret = -EINVAL;
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pci_warn(php_slot->pdev, "Cannot unflatten FDT\n");
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goto free_fdt;
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}
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/* Initialize and apply the changeset */
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of_changeset_init(&php_slot->ocs);
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pnv_php_reverse_nodes(php_slot->dn);
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ret = pnv_php_populate_changeset(&php_slot->ocs, php_slot->dn);
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if (ret) {
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pnv_php_reverse_nodes(php_slot->dn);
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pci_warn(php_slot->pdev, "Error %d populating changeset\n",
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ret);
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goto free_dt;
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}
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php_slot->dn->child = NULL;
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ret = of_changeset_apply(&php_slot->ocs);
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if (ret) {
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pci_warn(php_slot->pdev, "Error %d applying changeset\n", ret);
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goto destroy_changeset;
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}
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/* Add device node firmware data */
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pnv_php_add_pdns(php_slot);
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php_slot->fdt = fdt;
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php_slot->dt = dt;
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kfree(fdt1);
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goto out;
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destroy_changeset:
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of_changeset_destroy(&php_slot->ocs);
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free_dt:
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kfree(dt);
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php_slot->dn->child = NULL;
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free_fdt:
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kfree(fdt);
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free_fdt1:
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kfree(fdt1);
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out:
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return ret;
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}
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int pnv_php_set_slot_power_state(struct hotplug_slot *slot,
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uint8_t state)
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{
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struct pnv_php_slot *php_slot = slot->private;
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struct opal_msg msg;
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int ret;
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ret = pnv_pci_set_power_state(php_slot->id, state, &msg);
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if (ret > 0) {
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if (be64_to_cpu(msg.params[1]) != php_slot->dn->phandle ||
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be64_to_cpu(msg.params[2]) != state ||
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be64_to_cpu(msg.params[3]) != OPAL_SUCCESS) {
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pci_warn(php_slot->pdev, "Wrong msg (%lld, %lld, %lld)\n",
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be64_to_cpu(msg.params[1]),
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be64_to_cpu(msg.params[2]),
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be64_to_cpu(msg.params[3]));
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return -ENOMSG;
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}
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} else if (ret < 0) {
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pci_warn(php_slot->pdev, "Error %d powering %s\n",
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ret, (state == OPAL_PCI_SLOT_POWER_ON) ? "on" : "off");
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return ret;
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}
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if (state == OPAL_PCI_SLOT_POWER_OFF || state == OPAL_PCI_SLOT_OFFLINE)
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pnv_php_rmv_devtree(php_slot);
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else
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ret = pnv_php_add_devtree(php_slot);
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return ret;
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}
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EXPORT_SYMBOL_GPL(pnv_php_set_slot_power_state);
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static int pnv_php_get_power_state(struct hotplug_slot *slot, u8 *state)
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{
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struct pnv_php_slot *php_slot = slot->private;
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uint8_t power_state = OPAL_PCI_SLOT_POWER_ON;
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int ret;
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/*
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* Retrieve power status from firmware. If we fail
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* getting that, the power status fails back to
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* be on.
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*/
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ret = pnv_pci_get_power_state(php_slot->id, &power_state);
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if (ret) {
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pci_warn(php_slot->pdev, "Error %d getting power status\n",
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ret);
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} else {
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*state = power_state;
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slot->info->power_status = power_state;
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}
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return 0;
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}
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static int pnv_php_get_adapter_state(struct hotplug_slot *slot, u8 *state)
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{
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struct pnv_php_slot *php_slot = slot->private;
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uint8_t presence = OPAL_PCI_SLOT_EMPTY;
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int ret;
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/*
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* Retrieve presence status from firmware. If we can't
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* get that, it will fail back to be empty.
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*/
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ret = pnv_pci_get_presence_state(php_slot->id, &presence);
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if (ret >= 0) {
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*state = presence;
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slot->info->adapter_status = presence;
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ret = 0;
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} else {
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pci_warn(php_slot->pdev, "Error %d getting presence\n", ret);
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}
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return ret;
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}
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static int pnv_php_set_attention_state(struct hotplug_slot *slot, u8 state)
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{
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/* FIXME: Make it real once firmware supports it */
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slot->info->attention_status = state;
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return 0;
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}
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static int pnv_php_enable(struct pnv_php_slot *php_slot, bool rescan)
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{
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struct hotplug_slot *slot = &php_slot->slot;
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uint8_t presence = OPAL_PCI_SLOT_EMPTY;
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uint8_t power_status = OPAL_PCI_SLOT_POWER_ON;
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int ret;
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/* Check if the slot has been configured */
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if (php_slot->state != PNV_PHP_STATE_REGISTERED)
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return 0;
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/* Retrieve slot presence status */
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ret = pnv_php_get_adapter_state(slot, &presence);
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if (ret)
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return ret;
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/*
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* Proceed if there have nothing behind the slot. However,
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* we should leave the slot in registered state at the
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* beginning. Otherwise, the PCI devices inserted afterwards
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* won't be probed and populated.
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*/
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if (presence == OPAL_PCI_SLOT_EMPTY) {
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if (!php_slot->power_state_check) {
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php_slot->power_state_check = true;
|
|
|
|
return 0;
|
|
}
|
|
|
|
goto scan;
|
|
}
|
|
|
|
/*
|
|
* If the power supply to the slot is off, we can't detect
|
|
* adapter presence state. That means we have to turn the
|
|
* slot on before going to probe slot's presence state.
|
|
*
|
|
* On the first time, we don't change the power status to
|
|
* boost system boot with assumption that the firmware
|
|
* supplies consistent slot power status: empty slot always
|
|
* has its power off and non-empty slot has its power on.
|
|
*/
|
|
if (!php_slot->power_state_check) {
|
|
php_slot->power_state_check = true;
|
|
|
|
ret = pnv_php_get_power_state(slot, &power_status);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (power_status != OPAL_PCI_SLOT_POWER_ON)
|
|
return 0;
|
|
}
|
|
|
|
/* Check the power status. Scan the slot if it is already on */
|
|
ret = pnv_php_get_power_state(slot, &power_status);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (power_status == OPAL_PCI_SLOT_POWER_ON)
|
|
goto scan;
|
|
|
|
/* Power is off, turn it on and then scan the slot */
|
|
ret = pnv_php_set_slot_power_state(slot, OPAL_PCI_SLOT_POWER_ON);
|
|
if (ret)
|
|
return ret;
|
|
|
|
scan:
|
|
if (presence == OPAL_PCI_SLOT_PRESENT) {
|
|
if (rescan) {
|
|
pci_lock_rescan_remove();
|
|
pci_hp_add_devices(php_slot->bus);
|
|
pci_unlock_rescan_remove();
|
|
}
|
|
|
|
/* Rescan for child hotpluggable slots */
|
|
php_slot->state = PNV_PHP_STATE_POPULATED;
|
|
if (rescan)
|
|
pnv_php_register(php_slot->dn);
|
|
} else {
|
|
php_slot->state = PNV_PHP_STATE_POPULATED;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int pnv_php_enable_slot(struct hotplug_slot *slot)
|
|
{
|
|
struct pnv_php_slot *php_slot = container_of(slot,
|
|
struct pnv_php_slot, slot);
|
|
|
|
return pnv_php_enable(php_slot, true);
|
|
}
|
|
|
|
static int pnv_php_disable_slot(struct hotplug_slot *slot)
|
|
{
|
|
struct pnv_php_slot *php_slot = slot->private;
|
|
int ret;
|
|
|
|
if (php_slot->state != PNV_PHP_STATE_POPULATED)
|
|
return 0;
|
|
|
|
/* Remove all devices behind the slot */
|
|
pci_lock_rescan_remove();
|
|
pci_hp_remove_devices(php_slot->bus);
|
|
pci_unlock_rescan_remove();
|
|
|
|
/* Detach the child hotpluggable slots */
|
|
pnv_php_unregister(php_slot->dn);
|
|
|
|
/* Notify firmware and remove device nodes */
|
|
ret = pnv_php_set_slot_power_state(slot, OPAL_PCI_SLOT_POWER_OFF);
|
|
|
|
php_slot->state = PNV_PHP_STATE_REGISTERED;
|
|
return ret;
|
|
}
|
|
|
|
static struct hotplug_slot_ops php_slot_ops = {
|
|
.get_power_status = pnv_php_get_power_state,
|
|
.get_adapter_status = pnv_php_get_adapter_state,
|
|
.set_attention_status = pnv_php_set_attention_state,
|
|
.enable_slot = pnv_php_enable_slot,
|
|
.disable_slot = pnv_php_disable_slot,
|
|
};
|
|
|
|
static void pnv_php_release(struct pnv_php_slot *php_slot)
|
|
{
|
|
unsigned long flags;
|
|
|
|
/* Remove from global or child list */
|
|
spin_lock_irqsave(&pnv_php_lock, flags);
|
|
list_del(&php_slot->link);
|
|
spin_unlock_irqrestore(&pnv_php_lock, flags);
|
|
|
|
/* Detach from parent */
|
|
pnv_php_put_slot(php_slot);
|
|
pnv_php_put_slot(php_slot->parent);
|
|
}
|
|
|
|
static struct pnv_php_slot *pnv_php_alloc_slot(struct device_node *dn)
|
|
{
|
|
struct pnv_php_slot *php_slot;
|
|
struct pci_bus *bus;
|
|
const char *label;
|
|
uint64_t id;
|
|
int ret;
|
|
|
|
ret = of_property_read_string(dn, "ibm,slot-label", &label);
|
|
if (ret)
|
|
return NULL;
|
|
|
|
if (pnv_pci_get_slot_id(dn, &id))
|
|
return NULL;
|
|
|
|
bus = pci_find_bus_by_node(dn);
|
|
if (!bus)
|
|
return NULL;
|
|
|
|
php_slot = kzalloc(sizeof(*php_slot), GFP_KERNEL);
|
|
if (!php_slot)
|
|
return NULL;
|
|
|
|
php_slot->name = kstrdup(label, GFP_KERNEL);
|
|
if (!php_slot->name) {
|
|
kfree(php_slot);
|
|
return NULL;
|
|
}
|
|
|
|
if (dn->child && PCI_DN(dn->child))
|
|
php_slot->slot_no = PCI_SLOT(PCI_DN(dn->child)->devfn);
|
|
else
|
|
php_slot->slot_no = -1; /* Placeholder slot */
|
|
|
|
kref_init(&php_slot->kref);
|
|
php_slot->state = PNV_PHP_STATE_INITIALIZED;
|
|
php_slot->dn = dn;
|
|
php_slot->pdev = bus->self;
|
|
php_slot->bus = bus;
|
|
php_slot->id = id;
|
|
php_slot->power_state_check = false;
|
|
php_slot->slot.ops = &php_slot_ops;
|
|
php_slot->slot.info = &php_slot->slot_info;
|
|
php_slot->slot.private = php_slot;
|
|
|
|
INIT_LIST_HEAD(&php_slot->children);
|
|
INIT_LIST_HEAD(&php_slot->link);
|
|
|
|
return php_slot;
|
|
}
|
|
|
|
static int pnv_php_register_slot(struct pnv_php_slot *php_slot)
|
|
{
|
|
struct pnv_php_slot *parent;
|
|
struct device_node *dn = php_slot->dn;
|
|
unsigned long flags;
|
|
int ret;
|
|
|
|
/* Check if the slot is registered or not */
|
|
parent = pnv_php_find_slot(php_slot->dn);
|
|
if (parent) {
|
|
pnv_php_put_slot(parent);
|
|
return -EEXIST;
|
|
}
|
|
|
|
/* Register PCI slot */
|
|
ret = pci_hp_register(&php_slot->slot, php_slot->bus,
|
|
php_slot->slot_no, php_slot->name);
|
|
if (ret) {
|
|
pci_warn(php_slot->pdev, "Error %d registering slot\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
/* Attach to the parent's child list or global list */
|
|
while ((dn = of_get_parent(dn))) {
|
|
if (!PCI_DN(dn)) {
|
|
of_node_put(dn);
|
|
break;
|
|
}
|
|
|
|
parent = pnv_php_find_slot(dn);
|
|
if (parent) {
|
|
of_node_put(dn);
|
|
break;
|
|
}
|
|
|
|
of_node_put(dn);
|
|
}
|
|
|
|
spin_lock_irqsave(&pnv_php_lock, flags);
|
|
php_slot->parent = parent;
|
|
if (parent)
|
|
list_add_tail(&php_slot->link, &parent->children);
|
|
else
|
|
list_add_tail(&php_slot->link, &pnv_php_slot_list);
|
|
spin_unlock_irqrestore(&pnv_php_lock, flags);
|
|
|
|
php_slot->state = PNV_PHP_STATE_REGISTERED;
|
|
return 0;
|
|
}
|
|
|
|
static int pnv_php_enable_msix(struct pnv_php_slot *php_slot)
|
|
{
|
|
struct pci_dev *pdev = php_slot->pdev;
|
|
struct msix_entry entry;
|
|
int nr_entries, ret;
|
|
u16 pcie_flag;
|
|
|
|
/* Get total number of MSIx entries */
|
|
nr_entries = pci_msix_vec_count(pdev);
|
|
if (nr_entries < 0)
|
|
return nr_entries;
|
|
|
|
/* Check hotplug MSIx entry is in range */
|
|
pcie_capability_read_word(pdev, PCI_EXP_FLAGS, &pcie_flag);
|
|
entry.entry = (pcie_flag & PCI_EXP_FLAGS_IRQ) >> 9;
|
|
if (entry.entry >= nr_entries)
|
|
return -ERANGE;
|
|
|
|
/* Enable MSIx */
|
|
ret = pci_enable_msix_exact(pdev, &entry, 1);
|
|
if (ret) {
|
|
pci_warn(pdev, "Error %d enabling MSIx\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
return entry.vector;
|
|
}
|
|
|
|
static void pnv_php_event_handler(struct work_struct *work)
|
|
{
|
|
struct pnv_php_event *event =
|
|
container_of(work, struct pnv_php_event, work);
|
|
struct pnv_php_slot *php_slot = event->php_slot;
|
|
|
|
if (event->added)
|
|
pnv_php_enable_slot(&php_slot->slot);
|
|
else
|
|
pnv_php_disable_slot(&php_slot->slot);
|
|
|
|
kfree(event);
|
|
}
|
|
|
|
static irqreturn_t pnv_php_interrupt(int irq, void *data)
|
|
{
|
|
struct pnv_php_slot *php_slot = data;
|
|
struct pci_dev *pchild, *pdev = php_slot->pdev;
|
|
struct eeh_dev *edev;
|
|
struct eeh_pe *pe;
|
|
struct pnv_php_event *event;
|
|
u16 sts, lsts;
|
|
u8 presence;
|
|
bool added;
|
|
unsigned long flags;
|
|
int ret;
|
|
|
|
pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &sts);
|
|
sts &= (PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC);
|
|
pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, sts);
|
|
if (sts & PCI_EXP_SLTSTA_DLLSC) {
|
|
pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lsts);
|
|
added = !!(lsts & PCI_EXP_LNKSTA_DLLLA);
|
|
} else if (!(php_slot->flags & PNV_PHP_FLAG_BROKEN_PDC) &&
|
|
(sts & PCI_EXP_SLTSTA_PDC)) {
|
|
ret = pnv_pci_get_presence_state(php_slot->id, &presence);
|
|
if (ret) {
|
|
pci_warn(pdev, "PCI slot [%s] error %d getting presence (0x%04x), to retry the operation.\n",
|
|
php_slot->name, ret, sts);
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
added = !!(presence == OPAL_PCI_SLOT_PRESENT);
|
|
} else {
|
|
return IRQ_NONE;
|
|
}
|
|
|
|
/* Freeze the removed PE to avoid unexpected error reporting */
|
|
if (!added) {
|
|
pchild = list_first_entry_or_null(&php_slot->bus->devices,
|
|
struct pci_dev, bus_list);
|
|
edev = pchild ? pci_dev_to_eeh_dev(pchild) : NULL;
|
|
pe = edev ? edev->pe : NULL;
|
|
if (pe) {
|
|
eeh_serialize_lock(&flags);
|
|
eeh_pe_state_mark(pe, EEH_PE_ISOLATED);
|
|
eeh_serialize_unlock(flags);
|
|
eeh_pe_set_option(pe, EEH_OPT_FREEZE_PE);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* The PE is left in frozen state if the event is missed. It's
|
|
* fine as the PCI devices (PE) aren't functional any more.
|
|
*/
|
|
event = kzalloc(sizeof(*event), GFP_ATOMIC);
|
|
if (!event) {
|
|
pci_warn(pdev, "PCI slot [%s] missed hotplug event 0x%04x\n",
|
|
php_slot->name, sts);
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
pci_info(pdev, "PCI slot [%s] %s (IRQ: %d)\n",
|
|
php_slot->name, added ? "added" : "removed", irq);
|
|
INIT_WORK(&event->work, pnv_php_event_handler);
|
|
event->added = added;
|
|
event->php_slot = php_slot;
|
|
queue_work(php_slot->wq, &event->work);
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static void pnv_php_init_irq(struct pnv_php_slot *php_slot, int irq)
|
|
{
|
|
struct pci_dev *pdev = php_slot->pdev;
|
|
u32 broken_pdc = 0;
|
|
u16 sts, ctrl;
|
|
int ret;
|
|
|
|
/* Allocate workqueue */
|
|
php_slot->wq = alloc_workqueue("pciehp-%s", 0, 0, php_slot->name);
|
|
if (!php_slot->wq) {
|
|
pci_warn(pdev, "Cannot alloc workqueue\n");
|
|
pnv_php_disable_irq(php_slot, true);
|
|
return;
|
|
}
|
|
|
|
/* Check PDC (Presence Detection Change) is broken or not */
|
|
ret = of_property_read_u32(php_slot->dn, "ibm,slot-broken-pdc",
|
|
&broken_pdc);
|
|
if (!ret && broken_pdc)
|
|
php_slot->flags |= PNV_PHP_FLAG_BROKEN_PDC;
|
|
|
|
/* Clear pending interrupts */
|
|
pcie_capability_read_word(pdev, PCI_EXP_SLTSTA, &sts);
|
|
if (php_slot->flags & PNV_PHP_FLAG_BROKEN_PDC)
|
|
sts |= PCI_EXP_SLTSTA_DLLSC;
|
|
else
|
|
sts |= (PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC);
|
|
pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, sts);
|
|
|
|
/* Request the interrupt */
|
|
ret = request_irq(irq, pnv_php_interrupt, IRQF_SHARED,
|
|
php_slot->name, php_slot);
|
|
if (ret) {
|
|
pnv_php_disable_irq(php_slot, true);
|
|
pci_warn(pdev, "Error %d enabling IRQ %d\n", ret, irq);
|
|
return;
|
|
}
|
|
|
|
/* Enable the interrupts */
|
|
pcie_capability_read_word(pdev, PCI_EXP_SLTCTL, &ctrl);
|
|
if (php_slot->flags & PNV_PHP_FLAG_BROKEN_PDC) {
|
|
ctrl &= ~PCI_EXP_SLTCTL_PDCE;
|
|
ctrl |= (PCI_EXP_SLTCTL_HPIE |
|
|
PCI_EXP_SLTCTL_DLLSCE);
|
|
} else {
|
|
ctrl |= (PCI_EXP_SLTCTL_HPIE |
|
|
PCI_EXP_SLTCTL_PDCE |
|
|
PCI_EXP_SLTCTL_DLLSCE);
|
|
}
|
|
pcie_capability_write_word(pdev, PCI_EXP_SLTCTL, ctrl);
|
|
|
|
/* The interrupt is initialized successfully when @irq is valid */
|
|
php_slot->irq = irq;
|
|
}
|
|
|
|
static void pnv_php_enable_irq(struct pnv_php_slot *php_slot)
|
|
{
|
|
struct pci_dev *pdev = php_slot->pdev;
|
|
int irq, ret;
|
|
|
|
/*
|
|
* The MSI/MSIx interrupt might have been occupied by other
|
|
* drivers. Don't populate the surprise hotplug capability
|
|
* in that case.
|
|
*/
|
|
if (pci_dev_msi_enabled(pdev))
|
|
return;
|
|
|
|
ret = pci_enable_device(pdev);
|
|
if (ret) {
|
|
pci_warn(pdev, "Error %d enabling device\n", ret);
|
|
return;
|
|
}
|
|
|
|
pci_set_master(pdev);
|
|
|
|
/* Enable MSIx interrupt */
|
|
irq = pnv_php_enable_msix(php_slot);
|
|
if (irq > 0) {
|
|
pnv_php_init_irq(php_slot, irq);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Use MSI if MSIx doesn't work. Fail back to legacy INTx
|
|
* if MSI doesn't work either
|
|
*/
|
|
ret = pci_enable_msi(pdev);
|
|
if (!ret || pdev->irq) {
|
|
irq = pdev->irq;
|
|
pnv_php_init_irq(php_slot, irq);
|
|
}
|
|
}
|
|
|
|
static int pnv_php_register_one(struct device_node *dn)
|
|
{
|
|
struct pnv_php_slot *php_slot;
|
|
u32 prop32;
|
|
int ret;
|
|
|
|
/* Check if it's hotpluggable slot */
|
|
ret = of_property_read_u32(dn, "ibm,slot-pluggable", &prop32);
|
|
if (ret || !prop32)
|
|
return -ENXIO;
|
|
|
|
ret = of_property_read_u32(dn, "ibm,reset-by-firmware", &prop32);
|
|
if (ret || !prop32)
|
|
return -ENXIO;
|
|
|
|
php_slot = pnv_php_alloc_slot(dn);
|
|
if (!php_slot)
|
|
return -ENODEV;
|
|
|
|
ret = pnv_php_register_slot(php_slot);
|
|
if (ret)
|
|
goto free_slot;
|
|
|
|
ret = pnv_php_enable(php_slot, false);
|
|
if (ret)
|
|
goto unregister_slot;
|
|
|
|
/* Enable interrupt if the slot supports surprise hotplug */
|
|
ret = of_property_read_u32(dn, "ibm,slot-surprise-pluggable", &prop32);
|
|
if (!ret && prop32)
|
|
pnv_php_enable_irq(php_slot);
|
|
|
|
return 0;
|
|
|
|
unregister_slot:
|
|
pnv_php_unregister_one(php_slot->dn);
|
|
free_slot:
|
|
pnv_php_put_slot(php_slot);
|
|
return ret;
|
|
}
|
|
|
|
static void pnv_php_register(struct device_node *dn)
|
|
{
|
|
struct device_node *child;
|
|
|
|
/*
|
|
* The parent slots should be registered before their
|
|
* child slots.
|
|
*/
|
|
for_each_child_of_node(dn, child) {
|
|
pnv_php_register_one(child);
|
|
pnv_php_register(child);
|
|
}
|
|
}
|
|
|
|
static void pnv_php_unregister_one(struct device_node *dn)
|
|
{
|
|
struct pnv_php_slot *php_slot;
|
|
|
|
php_slot = pnv_php_find_slot(dn);
|
|
if (!php_slot)
|
|
return;
|
|
|
|
php_slot->state = PNV_PHP_STATE_OFFLINE;
|
|
pci_hp_deregister(&php_slot->slot);
|
|
pnv_php_release(php_slot);
|
|
pnv_php_put_slot(php_slot);
|
|
}
|
|
|
|
static void pnv_php_unregister(struct device_node *dn)
|
|
{
|
|
struct device_node *child;
|
|
|
|
/* The child slots should go before their parent slots */
|
|
for_each_child_of_node(dn, child) {
|
|
pnv_php_unregister(child);
|
|
pnv_php_unregister_one(child);
|
|
}
|
|
}
|
|
|
|
static int __init pnv_php_init(void)
|
|
{
|
|
struct device_node *dn;
|
|
|
|
pr_info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
|
|
for_each_compatible_node(dn, NULL, "ibm,ioda2-phb")
|
|
pnv_php_register(dn);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void __exit pnv_php_exit(void)
|
|
{
|
|
struct device_node *dn;
|
|
|
|
for_each_compatible_node(dn, NULL, "ibm,ioda2-phb")
|
|
pnv_php_unregister(dn);
|
|
}
|
|
|
|
module_init(pnv_php_init);
|
|
module_exit(pnv_php_exit);
|
|
|
|
MODULE_VERSION(DRIVER_VERSION);
|
|
MODULE_LICENSE("GPL v2");
|
|
MODULE_AUTHOR(DRIVER_AUTHOR);
|
|
MODULE_DESCRIPTION(DRIVER_DESC);
|