powerpc/eeh: Create PEs for PHBs

For one particular PE, it's only meaningful in the ancestor PHB
domain. Therefore, each PHB should have its own PE hierarchy tree
to trace those PEs created against the PHB.

The patch creates PEs for the PHBs and put those PEs into the
global link list traced by "eeh_phb_pe". The link list of PEs
would be first level of overall PE hierarchy tree across the
system.

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

1 files changed, 120 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 00000000000..7dee7dc8352
--- /dev/null
+++ b/arch/powerpc/platforms/pseries/eeh_pe.c
@@ -0,0 +1,120 @@
+/*
+ * 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;
+
+	eeh_lock();
+
+	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) {
+			eeh_unlock();
+			return pe;
+		}
+	}
+
+	eeh_unlock();
+
+	return NULL;
+}