powerpc/eeh: Introduce EEH device

Original EEH implementation depends on struct pci_dn heavily. However,
EEH shouldn't depend on that actually because EEH needn't share much
information with other PCI components. That's to say, EEH should have
worked independently.

The patch introduces struct eeh_dev so that EEH core components needn't
be working based on struct pci_dn in future. Also, struct pci_dn, struct
eeh_dev instances are created in dynamic fasion and the binding with EEH
device, OF node, PCI device is implemented as well.

The EEH devices are created after PHBs are detected and initialized, but
PCI emunation hasn't started yet. Apart from that, PHB might be created
dynamically through DLPAR component and the EEH devices should be creatd
as well. Another case might be OF node is created dynamically by DR
(Dynamic Reconfiguration), which has been defined by PAPR. For those OF
nodes created by DR, EEH devices should be also created accordingly. The
binding between EEH device and OF node is done while the EEH device is
initially created.

The binding between EEH device and PCI device should be done after PCI
emunation is done. Besides, PCI hotplug also needs the binding so that
the EEH devices could be traced from the newly coming PCI buses or PCI
devices.

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

arch/powerpc/include/asm/device.h

@@ -31,6 +31,9 @@ struct dev_archdata {
 #ifdef CONFIG_SWIOTLB
 	dma_addr_t		max_direct_dma_addr;
 #endif
+#ifdef CONFIG_EEH
+	struct eeh_dev		*edev;
+#endif
 };
 
 struct pdev_archdata {

arch/powerpc/include/asm/eeh.h

@@ -31,6 +31,43 @@ struct device_node;
 
 #ifdef CONFIG_EEH
 
+/*
+ * The struct is used to trace EEH state for the associated
+ * PCI device node or PCI device. In future, it might
+ * represent PE as well so that the EEH device to form
+ * another tree except the currently existing tree of PCI
+ * buses and PCI devices
+ */
+#define EEH_MODE_SUPPORTED	(1<<0)	/* EEH supported on the device	*/
+#define EEH_MODE_NOCHECK	(1<<1)	/* EEH check should be skipped	*/
+#define EEH_MODE_ISOLATED	(1<<2)	/* The device has been isolated	*/
+#define EEH_MODE_RECOVERING	(1<<3)	/* Recovering the device	*/
+#define EEH_MODE_IRQ_DISABLED	(1<<4)	/* Interrupt disabled		*/
+
+struct eeh_dev {
+	int mode;			/* EEH mode			*/
+	int class_code;			/* Class code of the device	*/
+	int config_addr;		/* Config address		*/
+	int pe_config_addr;		/* PE config address		*/
+	int check_count;		/* Times of ignored error	*/
+	int freeze_count;		/* Times of froze up		*/
+	int false_positives;		/* Times of reported #ff's	*/
+	u32 config_space[16];		/* Saved PCI config space	*/
+	struct pci_controller *phb;	/* Associated PHB		*/
+	struct device_node *dn;		/* Associated device node	*/
+	struct pci_dev *pdev;		/* Associated PCI device	*/
+};
+
+static inline struct device_node *eeh_dev_to_of_node(struct eeh_dev *edev)
+{
+	return edev->dn;
+}
+
+static inline struct pci_dev *eeh_dev_to_pci_dev(struct eeh_dev *edev)
+{
+	return edev->pdev;
+}
+
 /*
  * The struct is used to trace the registered EEH operation
  * callback functions. Actually, those operation callback
@@ -70,19 +107,15 @@ struct eeh_ops {
 extern struct eeh_ops *eeh_ops;
 extern int eeh_subsystem_enabled;
 
-/* Values for eeh_mode bits in device_node */
-#define EEH_MODE_SUPPORTED     (1<<0)
-#define EEH_MODE_NOCHECK       (1<<1)
-#define EEH_MODE_ISOLATED      (1<<2)
-#define EEH_MODE_RECOVERING    (1<<3)
-#define EEH_MODE_IRQ_DISABLED  (1<<4)
-
 /*
  * Max number of EEH freezes allowed before we consider the device
  * to be permanently disabled.
  */
 #define EEH_MAX_ALLOWED_FREEZES 5
 
+void * __devinit eeh_dev_init(struct device_node *dn, void *data);
+void __devinit eeh_dev_phb_init_dynamic(struct pci_controller *phb);
+void __init eeh_dev_phb_init(void);
 void __init eeh_init(void);
 #ifdef CONFIG_PPC_PSERIES
 int __init eeh_pseries_init(void);
@@ -113,6 +146,16 @@ void eeh_remove_bus_device(struct pci_dev *);
 #define EEH_IO_ERROR_VALUE(size)	(~0U >> ((4 - (size)) * 8))
 
 #else /* !CONFIG_EEH */
+
+static inline void *eeh_dev_init(struct device_node *dn, void *data)
+{
+	return NULL;
+}
+
+static inline void eeh_dev_phb_init_dynamic(struct pci_controller *phb) { }
+
+static inline void eeh_dev_phb_init(void) { }
+
 static inline void eeh_init(void) { }
 
 #ifdef CONFIG_PPC_PSERIES

arch/powerpc/kernel/of_platform.c

@@ -21,12 +21,13 @@
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/of_platform.h>
+#include <linux/atomic.h>
 
 #include <asm/errno.h>
 #include <asm/topology.h>
 #include <asm/pci-bridge.h>
 #include <asm/ppc-pci.h>
-#include <linux/atomic.h>
+#include <asm/eeh.h>
 
 #ifdef CONFIG_PPC_OF_PLATFORM_PCI
 
@@ -66,6 +67,9 @@ static int __devinit of_pci_phb_probe(struct platform_device *dev)
 	/* Init pci_dn data structures */
 	pci_devs_phb_init_dynamic(phb);
 
+	/* Create EEH devices for the PHB */
+	eeh_dev_phb_init_dynamic(phb);
+
 	/* Register devices with EEH */
 #ifdef CONFIG_EEH
 	if (dev->dev.of_node->child)

arch/powerpc/kernel/rtas_pci.c

@@ -275,6 +275,9 @@ void __init find_and_init_phbs(void)
 	of_node_put(root);
 	pci_devs_phb_init();
 
+	/* Create EEH devices for all PHBs */
+	eeh_dev_phb_init();
+
 	/*
 	 * pci_probe_only and pci_assign_all_buses can be set via properties
 	 * in chosen.

arch/powerpc/platforms/pseries/Makefile

@@ -6,7 +6,8 @@ obj-y			:= lpar.o hvCall.o nvram.o reconfig.o \
 			   firmware.o power.o dlpar.o mobility.o
 obj-$(CONFIG_SMP)	+= smp.o
 obj-$(CONFIG_SCANLOG)	+= scanlog.o
-obj-$(CONFIG_EEH)	+= eeh.o eeh_cache.o eeh_driver.o eeh_event.o eeh_sysfs.o eeh_pseries.o
+obj-$(CONFIG_EEH)	+= eeh.o eeh_dev.o eeh_cache.o eeh_driver.o \
+			   eeh_event.o eeh_sysfs.o eeh_pseries.o
 obj-$(CONFIG_KEXEC)	+= kexec.o
 obj-$(CONFIG_PCI)	+= pci.o pci_dlpar.o
 obj-$(CONFIG_PSERIES_MSI)	+= msi.o

arch/powerpc/platforms/pseries/eeh_dev.c

@@ -0,0 +1,102 @@
+/*
+ * The file intends to implement dynamic creation of EEH device, which will
+ * be bound with OF node and PCI device simutaneously. The EEH devices would
+ * be foundamental information for EEH core components to work proerly. Besides,
+ * We have to support multiple situations where dynamic creation of EEH device
+ * is required:
+ *
+ * 1) Before PCI emunation starts, we need create EEH devices according to the
+ *    PCI sensitive OF nodes.
+ * 2) When PCI emunation is done, we need do the binding between PCI device and
+ *    the associated EEH device.
+ * 3) DR (Dynamic Reconfiguration) would create PCI sensitive OF node. EEH device
+ *    will be created while PCI sensitive OF node is detected from DR.
+ * 4) PCI hotplug needs redoing the binding between PCI device and EEH device. If
+ *    PHB is newly inserted, we also need create EEH devices accordingly.
+ *
+ * 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>
+
+/**
+ * eeh_dev_init - Create EEH device according to OF node
+ * @dn: device node
+ * @data: PHB
+ *
+ * It will create EEH device according to the given OF node. The function
+ * might be called by PCI emunation, DR, PHB hotplug.
+ */
+void * __devinit eeh_dev_init(struct device_node *dn, void *data)
+{
+	struct pci_controller *phb = data;
+	struct eeh_dev *edev;
+
+	/* Allocate EEH device */
+	edev = zalloc_maybe_bootmem(sizeof(*edev), GFP_KERNEL);
+	if (!edev) {
+		pr_warning("%s: out of memory\n", __func__);
+		return NULL;
+	}
+
+	/* Associate EEH device with OF node */
+	dn->edev  = edev;
+	edev->dn  = dn;
+	edev->phb = phb;
+
+	return NULL;
+}
+
+/**
+ * eeh_dev_phb_init_dynamic - Create EEH devices for devices included in PHB
+ * @phb: PHB
+ *
+ * Scan the PHB OF node and its child association, then create the
+ * EEH devices accordingly
+ */
+void __devinit eeh_dev_phb_init_dynamic(struct pci_controller *phb)
+{
+	struct device_node *dn = phb->dn;
+
+	/* EEH device for PHB */
+	eeh_dev_init(dn, phb);
+
+	/* EEH devices for children OF nodes */
+	traverse_pci_devices(dn, eeh_dev_init, phb);
+}
+
+/**
+ * eeh_dev_phb_init - Create EEH devices for devices included in existing PHBs
+ *
+ * Scan all the existing PHBs and create EEH devices for their OF
+ * nodes and their children OF nodes
+ */
+void __init eeh_dev_phb_init(void)
+{
+	struct pci_controller *phb, *tmp;
+
+	list_for_each_entry_safe(phb, tmp, &hose_list, list_node)
+		eeh_dev_phb_init_dynamic(phb);
+}

arch/powerpc/platforms/pseries/pci_dlpar.c

@@ -147,6 +147,9 @@ struct pci_controller * __devinit init_phb_dynamic(struct device_node *dn)
 
 	pci_devs_phb_init_dynamic(phb);
 
+	/* Create EEH devices for the PHB */
+	eeh_dev_phb_init_dynamic(phb);
+
 	if (dn->child)
 		eeh_add_device_tree_early(dn);
 

arch/powerpc/platforms/pseries/setup.c

@@ -260,8 +260,12 @@ static int pci_dn_reconfig_notifier(struct notifier_block *nb, unsigned long act
 	switch (action) {
 	case PSERIES_RECONFIG_ADD:
 		pci = np->parent->data;
-		if (pci)
+		if (pci) {
 			update_dn_pci_info(np, pci->phb);
+
+			/* Create EEH device for the OF node */
+			eeh_dev_init(np, pci->phb);
+		}
 		break;
 	default:
 		err = NOTIFY_DONE;

include/linux/of.h

@@ -58,6 +58,9 @@ struct device_node {
 	struct	kref kref;
 	unsigned long _flags;
 	void	*data;
+#if defined(CONFIG_EEH)
+	struct eeh_dev *edev;
+#endif
 #if defined(CONFIG_SPARC)
 	char	*path_component_name;
 	unsigned int unique_id;
@@ -72,6 +75,13 @@ struct of_phandle_args {
 	uint32_t args[MAX_PHANDLE_ARGS];
 };
 
+#if defined(CONFIG_EEH)
+static inline struct eeh_dev *of_node_to_eeh_dev(struct device_node *dn)
+{
+	return dn->edev;
+}
+#endif
+
 #if defined(CONFIG_SPARC) || !defined(CONFIG_OF)
 /* Dummy ref counting routines - to be implemented later */
 static inline struct device_node *of_node_get(struct device_node *node)

include/linux/pci.h

@@ -1647,6 +1647,13 @@ static inline void pci_set_bus_of_node(struct pci_bus *bus) { }
 static inline void pci_release_bus_of_node(struct pci_bus *bus) { }
 #endif  /* CONFIG_OF */
 
+#ifdef CONFIG_EEH
+static inline struct eeh_dev *pci_dev_to_eeh_dev(struct pci_dev *pdev)
+{
+	return pdev->dev.archdata.edev;
+}
+#endif
+
 /**
  * pci_find_upstream_pcie_bridge - find upstream PCIe-to-PCI bridge of a device
  * @pdev: the PCI device