1 files changed, 652 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/eeh_pe.c b/arch/powerpc/platforms/pseries/eeh_pe.c
new file mode 100644
index 000000000000..797cd181dc3f
--- /dev/null
+++ b/arch/powerpc/platforms/pseries/eeh_pe.c
@@ -0,0 +1,652 @@
+/*
+ * 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 __devinit 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 (!(pe->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) {
+		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;
+}