powerpc/eeh: Move common part to kernel directory

The patch moves the common part of EEH core into arch/powerpc/kernel
directory so that we needn't PPC_PSERIES while compiling POWERNV
platform:

        * Move the EEH common part into arch/powerpc/kernel
        * Move the functions for PCI hotplug from pSeries platform to
          arch/powerpc/kernel/pci-hotplug.c
        * Move CONFIG_EEH from arch/powerpc/platforms/pseries/Kconfig to
          arch/powerpc/platforms/Kconfig
        * Adjust makefile accordingly

Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 653 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/eeh_pe.c b/arch/powerpc/kernel/eeh_pe.c
new file mode 100644
index 000000000000..9d4a9e8562b2
--- /dev/null
+++ b/arch/powerpc/kernel/eeh_pe.c
@@ -0,0 +1,653 @@
+/*
+ * The file intends to implement PE based on the information from
+ * platforms. Basically, there have 3 types of PEs: PHB/Bus/Device.
+ * All the PEs should be organized as hierarchy tree. The first level
+ * of the tree will be associated to existing PHBs since the particular
+ * PE is only meaningful in one PHB domain.
+ *
+ * Copyright Benjamin Herrenschmidt & Gavin Shan, IBM Corporation 2012.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ */
+
+#include <linux/export.h>
+#include <linux/gfp.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/pci.h>
+#include <linux/string.h>
+
+#include <asm/pci-bridge.h>
+#include <asm/ppc-pci.h>
+
+static LIST_HEAD(eeh_phb_pe);
+
+/**
+ * eeh_pe_alloc - Allocate PE
+ * @phb: PCI controller
+ * @type: PE type
+ *
+ * Allocate PE instance dynamically.
+ */
+static struct eeh_pe *eeh_pe_alloc(struct pci_controller *phb, int type)
+{
+        struct eeh_pe *pe;
+
+        /* Allocate PHB PE */
+        pe = kzalloc(sizeof(struct eeh_pe), GFP_KERNEL);
+        if (!pe) return NULL;
+
+        /* Initialize PHB PE */
+        pe->type = type;
+        pe->phb = phb;
+        INIT_LIST_HEAD(&pe->child_list);
+        INIT_LIST_HEAD(&pe->child);
+        INIT_LIST_HEAD(&pe->edevs);
+
+        return pe;
+}
+
+/**
+ * eeh_phb_pe_create - Create PHB PE
+ * @phb: PCI controller
+ *
+ * The function should be called while the PHB is detected during
+ * system boot or PCI hotplug in order to create PHB PE.
+ */
+int eeh_phb_pe_create(struct pci_controller *phb)
+{
+        struct eeh_pe *pe;
+
+        /* Allocate PHB PE */
+        pe = eeh_pe_alloc(phb, EEH_PE_PHB);
+        if (!pe) {
+                pr_err("%s: out of memory!\n", __func__);
+                return -ENOMEM;
+        }
+
+        /* Put it into the list */
+        eeh_lock();
+        list_add_tail(&pe->child, &eeh_phb_pe);
+        eeh_unlock();
+
+        pr_debug("EEH: Add PE for PHB#%d\n", phb->global_number);
+
+        return 0;
+}
+
+/**
+ * eeh_phb_pe_get - Retrieve PHB PE based on the given PHB
+ * @phb: PCI controller
+ *
+ * The overall PEs form hierarchy tree. The first layer of the
+ * hierarchy tree is composed of PHB PEs. The function is used
+ * to retrieve the corresponding PHB PE according to the given PHB.
+ */
+static struct eeh_pe *eeh_phb_pe_get(struct pci_controller *phb)
+{
+        struct eeh_pe *pe;
+
+        list_for_each_entry(pe, &eeh_phb_pe, child) {
+                /*
+                 * Actually, we needn't check the type since
+                 * the PE for PHB has been determined when that
+                 * was created.
+                 */
+                if ((pe->type & EEH_PE_PHB) && pe->phb == phb)
+                        return pe;
+        }
+
+        return NULL;
+}
+
+/**
+ * eeh_pe_next - Retrieve the next PE in the tree
+ * @pe: current PE
+ * @root: root PE
+ *
+ * The function is used to retrieve the next PE in the
+ * hierarchy PE tree.
+ */
+static struct eeh_pe *eeh_pe_next(struct eeh_pe *pe,
+                                  struct eeh_pe *root)
+{
+        struct list_head *next = pe->child_list.next;
+
+        if (next == &pe->child_list) {
+                while (1) {
+                        if (pe == root)
+                                return NULL;
+                        next = pe->child.next;
+                        if (next != &pe->parent->child_list)
+                                break;
+                        pe = pe->parent;
+                }
+        }
+
+        return list_entry(next, struct eeh_pe, child);
+}
+
+/**
+ * eeh_pe_traverse - Traverse PEs in the specified PHB
+ * @root: root PE
+ * @fn: callback
+ * @flag: extra parameter to callback
+ *
+ * The function is used to traverse the specified PE and its
+ * child PEs. The traversing is to be terminated once the
+ * callback returns something other than NULL, or no more PEs
+ * to be traversed.
+ */
+static void *eeh_pe_traverse(struct eeh_pe *root,
+                        eeh_traverse_func fn, void *flag)
+{
+        struct eeh_pe *pe;
+        void *ret;
+
+        for (pe = root; pe; pe = eeh_pe_next(pe, root)) {
+                ret = fn(pe, flag);
+                if (ret) return ret;
+        }
+
+        return NULL;
+}
+
+/**
+ * eeh_pe_dev_traverse - Traverse the devices from the PE
+ * @root: EEH PE
+ * @fn: function callback
+ * @flag: extra parameter to callback
+ *
+ * The function is used to traverse the devices of the specified
+ * PE and its child PEs.
+ */
+void *eeh_pe_dev_traverse(struct eeh_pe *root,
+                eeh_traverse_func fn, void *flag)
+{
+        struct eeh_pe *pe;
+        struct eeh_dev *edev;
+        void *ret;
+
+        if (!root) {
+                pr_warning("%s: Invalid PE %p\n", __func__, root);
+                return NULL;
+        }
+
+        eeh_lock();
+
+        /* Traverse root PE */
+        for (pe = root; pe; pe = eeh_pe_next(pe, root)) {
+                eeh_pe_for_each_dev(pe, edev) {
+                        ret = fn(edev, flag);
+                        if (ret) {
+                                eeh_unlock();
+                                return ret;
+                        }
+                }
+        }
+
+        eeh_unlock();
+
+        return NULL;
+}
+
+/**
+ * __eeh_pe_get - Check the PE address
+ * @data: EEH PE
+ * @flag: EEH device
+ *
+ * For one particular PE, it can be identified by PE address
+ * or tranditional BDF address. BDF address is composed of
+ * Bus/Device/Function number. The extra data referred by flag
+ * indicates which type of address should be used.
+ */
+static void *__eeh_pe_get(void *data, void *flag)
+{
+        struct eeh_pe *pe = (struct eeh_pe *)data;
+        struct eeh_dev *edev = (struct eeh_dev *)flag;
+
+        /* Unexpected PHB PE */
+        if (pe->type & EEH_PE_PHB)
+                return NULL;
+
+        /* We prefer PE address */
+        if (edev->pe_config_addr &&
+           (edev->pe_config_addr == pe->addr))
+                return pe;
+
+        /* Try BDF address */
+        if (edev->pe_config_addr &&
+           (edev->config_addr == pe->config_addr))
+                return pe;
+
+        return NULL;
+}
+
+/**
+ * eeh_pe_get - Search PE based on the given address
+ * @edev: EEH device
+ *
+ * Search the corresponding PE based on the specified address which
+ * is included in the eeh device. The function is used to check if
+ * the associated PE has been created against the PE address. It's
+ * notable that the PE address has 2 format: traditional PE address
+ * which is composed of PCI bus/device/function number, or unified
+ * PE address.
+ */
+static struct eeh_pe *eeh_pe_get(struct eeh_dev *edev)
+{
+        struct eeh_pe *root = eeh_phb_pe_get(edev->phb);
+        struct eeh_pe *pe;
+
+        pe = eeh_pe_traverse(root, __eeh_pe_get, edev);
+
+        return pe;
+}
+
+/**
+ * eeh_pe_get_parent - Retrieve the parent PE
+ * @edev: EEH device
+ *
+ * The whole PEs existing in the system are organized as hierarchy
+ * tree. The function is used to retrieve the parent PE according
+ * to the parent EEH device.
+ */
+static struct eeh_pe *eeh_pe_get_parent(struct eeh_dev *edev)
+{
+        struct device_node *dn;
+        struct eeh_dev *parent;
+
+        /*
+         * It might have the case for the indirect parent
+         * EEH device already having associated PE, but
+         * the direct parent EEH device doesn't have yet.
+         */
+        dn = edev->dn->parent;
+        while (dn) {
+                /* We're poking out of PCI territory */
+                if (!PCI_DN(dn)) return NULL;
+
+                parent = of_node_to_eeh_dev(dn);
+                /* We're poking out of PCI territory */
+                if (!parent) return NULL;
+
+                if (parent->pe)
+                        return parent->pe;
+
+                dn = dn->parent;
+        }
+
+        return NULL;
+}
+
+/**
+ * eeh_add_to_parent_pe - Add EEH device to parent PE
+ * @edev: EEH device
+ *
+ * Add EEH device to the parent PE. If the parent PE already
+ * exists, the PE type will be changed to EEH_PE_BUS. Otherwise,
+ * we have to create new PE to hold the EEH device and the new
+ * PE will be linked to its parent PE as well.
+ */
+int eeh_add_to_parent_pe(struct eeh_dev *edev)
+{
+        struct eeh_pe *pe, *parent;
+
+        eeh_lock();
+
+        /*
+         * Search the PE has been existing or not according
+         * to the PE address. If that has been existing, the
+         * PE should be composed of PCI bus and its subordinate
+         * components.
+         */
+        pe = eeh_pe_get(edev);
+        if (pe && !(pe->type & EEH_PE_INVALID)) {
+                if (!edev->pe_config_addr) {
+                        eeh_unlock();
+                        pr_err("%s: PE with addr 0x%x already exists\n",
+                                __func__, edev->config_addr);
+                        return -EEXIST;
+                }
+
+                /* Mark the PE as type of PCI bus */
+                pe->type = EEH_PE_BUS;
+                edev->pe = pe;
+
+                /* Put the edev to PE */
+                list_add_tail(&edev->list, &pe->edevs);
+                eeh_unlock();
+                pr_debug("EEH: Add %s to Bus PE#%x\n",
+                        edev->dn->full_name, pe->addr);
+
+                return 0;
+        } else if (pe && (pe->type & EEH_PE_INVALID)) {
+                list_add_tail(&edev->list, &pe->edevs);
+                edev->pe = pe;
+                /*
+                 * We're running to here because of PCI hotplug caused by
+                 * EEH recovery. We need clear EEH_PE_INVALID until the top.
+                 */
+                parent = pe;
+                while (parent) {
+                        if (!(parent->type & EEH_PE_INVALID))
+                                break;
+                        parent->type &= ~EEH_PE_INVALID;
+                        parent = parent->parent;
+                }
+                eeh_unlock();
+                pr_debug("EEH: Add %s to Device PE#%x, Parent PE#%x\n",
+                        edev->dn->full_name, pe->addr, pe->parent->addr);
+
+                return 0;
+        }
+
+        /* Create a new EEH PE */
+        pe = eeh_pe_alloc(edev->phb, EEH_PE_DEVICE);
+        if (!pe) {
+                eeh_unlock();
+                pr_err("%s: out of memory!\n", __func__);
+                return -ENOMEM;
+        }
+        pe->addr        = edev->pe_config_addr;
+        pe->config_addr = edev->config_addr;
+
+        /*
+         * Put the new EEH PE into hierarchy tree. If the parent
+         * can't be found, the newly created PE will be attached
+         * to PHB directly. Otherwise, we have to associate the
+         * PE with its parent.
+         */
+        parent = eeh_pe_get_parent(edev);
+        if (!parent) {
+                parent = eeh_phb_pe_get(edev->phb);
+                if (!parent) {
+                        eeh_unlock();
+                        pr_err("%s: No PHB PE is found (PHB Domain=%d)\n",
+                                __func__, edev->phb->global_number);
+                        edev->pe = NULL;
+                        kfree(pe);
+                        return -EEXIST;
+                }
+        }
+        pe->parent = parent;
+
+        /*
+         * Put the newly created PE into the child list and
+         * link the EEH device accordingly.
+         */
+        list_add_tail(&pe->child, &parent->child_list);
+        list_add_tail(&edev->list, &pe->edevs);
+        edev->pe = pe;
+        eeh_unlock();
+        pr_debug("EEH: Add %s to Device PE#%x, Parent PE#%x\n",
+                edev->dn->full_name, pe->addr, pe->parent->addr);
+
+        return 0;
+}
+
+/**
+ * eeh_rmv_from_parent_pe - Remove one EEH device from the associated PE
+ * @edev: EEH device
+ * @purge_pe: remove PE or not
+ *
+ * The PE hierarchy tree might be changed when doing PCI hotplug.
+ * Also, the PCI devices or buses could be removed from the system
+ * during EEH recovery. So we have to call the function remove the
+ * corresponding PE accordingly if necessary.
+ */
+int eeh_rmv_from_parent_pe(struct eeh_dev *edev, int purge_pe)
+{
+        struct eeh_pe *pe, *parent, *child;
+        int cnt;
+
+        if (!edev->pe) {
+                pr_warning("%s: No PE found for EEH device %s\n",
+                        __func__, edev->dn->full_name);
+                return -EEXIST;
+        }
+
+        eeh_lock();
+
+        /* Remove the EEH device */
+        pe = edev->pe;
+        edev->pe = NULL;
+        list_del(&edev->list);
+
+        /*
+         * Check if the parent PE includes any EEH devices.
+         * If not, we should delete that. Also, we should
+         * delete the parent PE if it doesn't have associated
+         * child PEs and EEH devices.
+         */
+        while (1) {
+                parent = pe->parent;
+                if (pe->type & EEH_PE_PHB)
+                        break;
+
+                if (purge_pe) {
+                        if (list_empty(&pe->edevs) &&
+                            list_empty(&pe->child_list)) {
+                                list_del(&pe->child);
+                                kfree(pe);
+                        } else {
+                                break;
+                        }
+                } else {
+                        if (list_empty(&pe->edevs)) {
+                                cnt = 0;
+                                list_for_each_entry(child, &pe->child_list, child) {
+                                        if (!(child->type & EEH_PE_INVALID)) {
+                                                cnt++;
+                                                break;
+                                        }
+                                }
+
+                                if (!cnt)
+                                        pe->type |= EEH_PE_INVALID;
+                                else
+                                        break;
+                        }
+                }
+
+                pe = parent;
+        }
+
+        eeh_unlock();
+
+        return 0;
+}
+
+/**
+ * __eeh_pe_state_mark - Mark the state for the PE
+ * @data: EEH PE
+ * @flag: state
+ *
+ * The function is used to mark the indicated state for the given
+ * PE. Also, the associated PCI devices will be put into IO frozen
+ * state as well.
+ */
+static void *__eeh_pe_state_mark(void *data, void *flag)
+{
+        struct eeh_pe *pe = (struct eeh_pe *)data;
+        int state = *((int *)flag);
+        struct eeh_dev *tmp;
+        struct pci_dev *pdev;
+
+        /*
+         * Mark the PE with the indicated state. Also,
+         * the associated PCI device will be put into
+         * I/O frozen state to avoid I/O accesses from
+         * the PCI device driver.
+         */
+        pe->state |= state;
+        eeh_pe_for_each_dev(pe, tmp) {
+                pdev = eeh_dev_to_pci_dev(tmp);
+                if (pdev)
+                        pdev->error_state = pci_channel_io_frozen;
+        }
+
+        return NULL;
+}
+
+/**
+ * eeh_pe_state_mark - Mark specified state for PE and its associated device
+ * @pe: EEH PE
+ *
+ * EEH error affects the current PE and its child PEs. The function
+ * is used to mark appropriate state for the affected PEs and the
+ * associated devices.
+ */
+void eeh_pe_state_mark(struct eeh_pe *pe, int state)
+{
+        eeh_lock();
+        eeh_pe_traverse(pe, __eeh_pe_state_mark, &state);
+        eeh_unlock();
+}
+
+/**
+ * __eeh_pe_state_clear - Clear state for the PE
+ * @data: EEH PE
+ * @flag: state
+ *
+ * The function is used to clear the indicated state from the
+ * given PE. Besides, we also clear the check count of the PE
+ * as well.
+ */
+static void *__eeh_pe_state_clear(void *data, void *flag)
+{
+        struct eeh_pe *pe = (struct eeh_pe *)data;
+        int state = *((int *)flag);
+
+        pe->state &= ~state;
+        pe->check_count = 0;
+
+        return NULL;
+}
+
+/**
+ * eeh_pe_state_clear - Clear state for the PE and its children
+ * @pe: PE
+ * @state: state to be cleared
+ *
+ * When the PE and its children has been recovered from error,
+ * we need clear the error state for that. The function is used
+ * for the purpose.
+ */
+void eeh_pe_state_clear(struct eeh_pe *pe, int state)
+{
+        eeh_lock();
+        eeh_pe_traverse(pe, __eeh_pe_state_clear, &state);
+        eeh_unlock();
+}
+
+/**
+ * eeh_restore_one_device_bars - Restore the Base Address Registers for one device
+ * @data: EEH device
+ * @flag: Unused
+ *
+ * Loads the PCI configuration space base address registers,
+ * the expansion ROM base address, the latency timer, and etc.
+ * from the saved values in the device node.
+ */
+static void *eeh_restore_one_device_bars(void *data, void *flag)
+{
+        int i;
+        u32 cmd;
+        struct eeh_dev *edev = (struct eeh_dev *)data;
+        struct device_node *dn = eeh_dev_to_of_node(edev);
+
+        for (i = 4; i < 10; i++)
+                eeh_ops->write_config(dn, i*4, 4, edev->config_space[i]);
+        /* 12 == Expansion ROM Address */
+        eeh_ops->write_config(dn, 12*4, 4, edev->config_space[12]);
+
+#define BYTE_SWAP(OFF) (8*((OFF)/4)+3-(OFF))
+#define SAVED_BYTE(OFF) (((u8 *)(edev->config_space))[BYTE_SWAP(OFF)])
+
+        eeh_ops->write_config(dn, PCI_CACHE_LINE_SIZE, 1,
+                SAVED_BYTE(PCI_CACHE_LINE_SIZE));
+        eeh_ops->write_config(dn, PCI_LATENCY_TIMER, 1,
+                SAVED_BYTE(PCI_LATENCY_TIMER));
+
+        /* max latency, min grant, interrupt pin and line */
+        eeh_ops->write_config(dn, 15*4, 4, edev->config_space[15]);
+
+        /*
+         * Restore PERR & SERR bits, some devices require it,
+         * don't touch the other command bits
+         */
+        eeh_ops->read_config(dn, PCI_COMMAND, 4, &cmd);
+        if (edev->config_space[1] & PCI_COMMAND_PARITY)
+                cmd |= PCI_COMMAND_PARITY;
+        else
+                cmd &= ~PCI_COMMAND_PARITY;
+        if (edev->config_space[1] & PCI_COMMAND_SERR)
+                cmd |= PCI_COMMAND_SERR;
+        else
+                cmd &= ~PCI_COMMAND_SERR;
+        eeh_ops->write_config(dn, PCI_COMMAND, 4, cmd);
+
+        return NULL;
+}
+
+/**
+ * eeh_pe_restore_bars - Restore the PCI config space info
+ * @pe: EEH PE
+ *
+ * This routine performs a recursive walk to the children
+ * of this device as well.
+ */
+void eeh_pe_restore_bars(struct eeh_pe *pe)
+{
+        /*
+         * We needn't take the EEH lock since eeh_pe_dev_traverse()
+         * will take that.
+         */
+        eeh_pe_dev_traverse(pe, eeh_restore_one_device_bars, NULL);
+}
+
+/**
+ * eeh_pe_bus_get - Retrieve PCI bus according to the given PE
+ * @pe: EEH PE
+ *
+ * Retrieve the PCI bus according to the given PE. Basically,
+ * there're 3 types of PEs: PHB/Bus/Device. For PHB PE, the
+ * primary PCI bus will be retrieved. The parent bus will be
+ * returned for BUS PE. However, we don't have associated PCI
+ * bus for DEVICE PE.
+ */
+struct pci_bus *eeh_pe_bus_get(struct eeh_pe *pe)
+{
+        struct pci_bus *bus = NULL;
+        struct eeh_dev *edev;
+        struct pci_dev *pdev;
+
+        eeh_lock();
+
+        if (pe->type & EEH_PE_PHB) {
+                bus = pe->phb->bus;
+        } else if (pe->type & EEH_PE_BUS ||
+                   pe->type & EEH_PE_DEVICE) {
+                edev = list_first_entry(&pe->edevs, struct eeh_dev, list);
+                pdev = eeh_dev_to_pci_dev(edev);
+                if (pdev)
+                        bus = pdev->bus;
+        }
+
+        eeh_unlock();
+
+        return bus;
+}