On Tue, Jun 30, 2015 at 07:18:04PM +0100, Grant Likely wrote:
>On Thu, 4 Jun 2015 16:42:11 +1000
>, Gavin Shan <gws...@linux.vnet.ibm.com>
> wrote:
>> The patch intends to add standalone driver to support PCI hotplug
>> for PowerPC PowerNV platform, which runs on top of skiboot firmware.
>> The firmware identified hotpluggable slots and marked their device
>> tree node with proper "ibm,slot-pluggable" and "ibm,reset-by-firmware".
>> The driver simply scans device-tree to create/register PCI hotplug slot
>> accordingly.
>>
>> If the skiboot firmware doesn't support slot status retrieval, the PCI
>> slot device node shouldn't have property "ibm,reset-by-firmware". In
>> that case, none of valid PCI slots will be detected from device tree.
>> The skiboot firmware doesn't export the capability to access attention
>> LEDs yet and it's something for TBD.
>>
>> Signed-off-by: Gavin Shan <gws...@linux.vnet.ibm.com>
>> ---
>> v5:
>> * Use OF OVERLAY to update the device-tree
>> * Removed unnecessary header files
>> * More meaningful return value from powernv_php_register_one()
>> * Use pnv_pci_hotplug_notifier_{register, unregister}()
>> * Decimal values for slot's states
>> * Removed struct powernv_php_slot::release()
>> * Merged two bool arguments to one for powernv_php_slot_enable()
>> * Rename release_device_nodes_info() to remove_device_nodes_info()
>> * Don't check on "!len" in slot_power_on_handler()
>> * Handle return value in get_adapter_status() as suggested by aik
>> * Drop invalid attention status in set_attention_status()
>> * Renaming functions
>> * Fixed coding style and added entry in MAINTAINERS reported by
>> checkpatch.pl
>> ---
>> MAINTAINERS | 6 +
>> drivers/pci/hotplug/Kconfig | 12 +
>> drivers/pci/hotplug/Makefile | 4 +
>> drivers/pci/hotplug/powernv_php.c | 140 +++++++
>> drivers/pci/hotplug/powernv_php.h | 90 ++++
>> drivers/pci/hotplug/powernv_php_slot.c | 732
>> +++++++++++++++++++++++++++++++++
>> 6 files changed, 984 insertions(+)
>> create mode 100644 drivers/pci/hotplug/powernv_php.c
>> create mode 100644 drivers/pci/hotplug/powernv_php.h
>> create mode 100644 drivers/pci/hotplug/powernv_php_slot.c
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index e308718..f5e1dce 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -7481,6 +7481,12 @@ L: linux-...@vger.kernel.org
>> S: Supported
>> F: Documentation/PCI/pci-error-recovery.txt
>>
>> +PCI HOTPLUG DRIVER FOR POWERNV PLATFORM
>> +M: Gavin Shan <gws...@linux.vnet.ibm.com>
>> +L: linux-...@vger.kernel.org
>> +S: Supported
>> +F: drivers/pci/hotplug/powernv_php*
>> +
>> PCI SUBSYSTEM
>> M: Bjorn Helgaas <bhelg...@google.com>
>> L: linux-...@vger.kernel.org
>> diff --git a/drivers/pci/hotplug/Kconfig b/drivers/pci/hotplug/Kconfig
>> index df8caec..ef55dae 100644
>> --- a/drivers/pci/hotplug/Kconfig
>> +++ b/drivers/pci/hotplug/Kconfig
>> @@ -113,6 +113,18 @@ config HOTPLUG_PCI_SHPC
>>
>> When in doubt, say N.
>>
>> +config HOTPLUG_PCI_POWERNV
>> + tristate "PowerPC PowerNV PCI Hotplug driver"
>> + depends on PPC_POWERNV && EEH
>> + help
>> + Say Y here if you run PowerPC PowerNV platform that supports
>> + PCI Hotplug
>> +
>> + To compile this driver as a module, choose M here: the
>> + module will be called powernv-php.
>> +
>> + When in doubt, say N.
>> +
>> config HOTPLUG_PCI_RPA
>> tristate "RPA PCI Hotplug driver"
>> depends on PPC_PSERIES && EEH
>> diff --git a/drivers/pci/hotplug/Makefile b/drivers/pci/hotplug/Makefile
>> index 4a9aa08..a69665e 100644
>> --- a/drivers/pci/hotplug/Makefile
>> +++ b/drivers/pci/hotplug/Makefile
>> @@ -14,6 +14,7 @@ obj-$(CONFIG_HOTPLUG_PCI_PCIE) += pciehp.o
>> obj-$(CONFIG_HOTPLUG_PCI_CPCI_ZT5550) += cpcihp_zt5550.o
>> obj-$(CONFIG_HOTPLUG_PCI_CPCI_GENERIC) += cpcihp_generic.o
>> obj-$(CONFIG_HOTPLUG_PCI_SHPC) += shpchp.o
>> +obj-$(CONFIG_HOTPLUG_PCI_POWERNV) += powernv-php.o
>> obj-$(CONFIG_HOTPLUG_PCI_RPA) += rpaphp.o
>> obj-$(CONFIG_HOTPLUG_PCI_RPA_DLPAR) += rpadlpar_io.o
>> obj-$(CONFIG_HOTPLUG_PCI_SGI) += sgi_hotplug.o
>> @@ -50,6 +51,9 @@ ibmphp-objs := ibmphp_core.o \
>> acpiphp-objs := acpiphp_core.o \
>> acpiphp_glue.o
>>
>> +powernv-php-objs := powernv_php.o \
>> + powernv_php_slot.o
>> +
>> rpaphp-objs := rpaphp_core.o \
>> rpaphp_pci.o \
>> rpaphp_slot.o
>> diff --git a/drivers/pci/hotplug/powernv_php.c
>> b/drivers/pci/hotplug/powernv_php.c
>> new file mode 100644
>> index 0000000..4cbff7a
>> --- /dev/null
>> +++ b/drivers/pci/hotplug/powernv_php.c
>> @@ -0,0 +1,140 @@
>> +/*
>> + * PCI Hotplug Driver for PowerPC PowerNV platform.
>> + *
>> + * Copyright Gavin Shan, IBM Corporation 2015.
>> + *
>> + * 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.
>> + */
>> +
>> +#include <linux/module.h>
>> +
>> +#include <asm/opal.h>
>> +#include <asm/pnv-pci.h>
>> +
>> +#include "powernv_php.h"
>> +
>> +#define DRIVER_VERSION "0.1"
>> +#define DRIVER_AUTHOR "Gavin Shan, IBM Corporation"
>> +#define DRIVER_DESC "PowerPC PowerNV PCI Hotplug Driver"
>> +
>> +static struct notifier_block php_msg_nb = {
>> + .notifier_call = powernv_php_msg_handler,
>> + .next = NULL,
>> + .priority = 0,
>> +};
>> +
>> +static int powernv_php_register_one(struct device_node *dn)
>> +{
>> + struct powernv_php_slot *slot;
>> + const __be32 *prop32;
>> + int ret;
>> +
>> + /* Check if it's hotpluggable slot */
>> + prop32 = of_get_property(dn, "ibm,slot-pluggable", NULL);
>> + if (!prop32 || !of_read_number(prop32, 1))
>> + return -ENXIO;
>> +
>> + prop32 = of_get_property(dn, "ibm,reset-by-firmware", NULL);
>> + if (!prop32 || !of_read_number(prop32, 1))
>> + return -ENXIO;
>> +
>> + /* Allocate slot */
>> + slot = powernv_php_slot_alloc(dn);
>> + if (!slot)
>> + return -ENODEV;
>> +
>> + /* Register it */
>> + ret = powernv_php_slot_register(slot);
>> + if (ret) {
>> + powernv_php_slot_put(slot);
>> + return ret;
>> + }
>> +
>> + return powernv_php_slot_enable(slot->php_slot, false);
>> +}
>> +
>> +int powernv_php_register(struct device_node *dn)
>> +{
>> + struct device_node *child;
>> + int ret = 0;
>> +
>> + /*
>> + * The parent slots should be registered before their
>> + * child slots.
>> + */
>> + for_each_child_of_node(dn, child) {
>> + powernv_php_register_one(child);
>> + powernv_php_register(child);
>> + }
>> +
>> + return ret;
>> +}
>> +
>> +static void powernv_php_unregister_one(struct device_node *dn)
>> +{
>> + struct powernv_php_slot *slot;
>> +
>> + slot = powernv_php_slot_find(dn);
>> + if (!slot)
>> + return;
>> +
>> + pci_hp_deregister(slot->php_slot);
>> +}
>> +
>> +void powernv_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) {
>> + powernv_php_unregister(child);
>> + powernv_php_unregister_one(child);
>> + }
>> +}
>> +
>> +static int __init powernv_php_init(void)
>> +{
>> + struct device_node *dn;
>> + int ret;
>> +
>> + pr_info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
>> +
>> + /* Register hotplug message handler */
>> + ret = pnv_pci_hotplug_notifier_register(&php_msg_nb);
>> + if (ret) {
>> + pr_warn("%s: Error %d registering hotplug notifier\n",
>> + __func__, ret);
>> + return ret;
>> + }
>> +
>> + /* Scan PHB nodes and their children */
>> + for_each_compatible_node(dn, NULL, "ibm,ioda-phb")
>> + powernv_php_register(dn);
>> + for_each_compatible_node(dn, NULL, "ibm,ioda2-phb")
>> + powernv_php_register(dn);
>> +
>> + return 0;
>> +}
>> +
>> +static void __exit powernv_php_exit(void)
>> +{
>> + struct device_node *dn;
>> +
>> + pnv_pci_hotplug_notifier_unregister(&php_msg_nb);
>> +
>> + for_each_compatible_node(dn, NULL, "ibm,ioda-phb")
>> + powernv_php_unregister(dn);
>> + for_each_compatible_node(dn, NULL, "ibm,ioda2-phb")
>> + powernv_php_unregister(dn);
>> +}
>> +
>> +module_init(powernv_php_init);
>> +module_exit(powernv_php_exit);
>> +
>> +MODULE_VERSION(DRIVER_VERSION);
>> +MODULE_LICENSE("GPL v2");
>> +MODULE_AUTHOR(DRIVER_AUTHOR);
>> +MODULE_DESCRIPTION(DRIVER_DESC);
>> diff --git a/drivers/pci/hotplug/powernv_php.h
>> b/drivers/pci/hotplug/powernv_php.h
>> new file mode 100644
>> index 0000000..5e14a65
>> --- /dev/null
>> +++ b/drivers/pci/hotplug/powernv_php.h
>> @@ -0,0 +1,90 @@
>> +/*
>> + * PCI Hotplug Driver for PowerPC PowerNV platform.
>> + *
>> + * Copyright Gavin Shan, IBM Corporation 2015.
>> + *
>> + * 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.
>> + */
>> +
>> +#ifndef _POWERNV_PHP_H
>> +#define _POWERNV_PHP_H
>> +
>> +#include <linux/list.h>
>> +#include <linux/kref.h>
>> +#include <linux/of.h>
>> +#include <linux/pci.h>
>> +#include <linux/pci_hotplug.h>
>> +#include <linux/wait.h>
>> +#include <linux/workqueue.h>
>> +
>> +#include <asm/opal-api.h>
>> +
>> +/* Slot power status */
>> +#define POWERNV_PHP_SLOT_POWER_OFF 0
>> +#define POWERNV_PHP_SLOT_POWER_ON 1
>> +
>> +/* Slot presence status */
>> +#define POWERNV_PHP_SLOT_EMPTY 0
>> +#define POWERNV_PHP_SLOT_PRESENT 1
>> +
>> +/* Slot attention status */
>> +#define POWERNV_PHP_SLOT_ATTEN_OFF 0
>> +#define POWERNV_PHP_SLOT_ATTEN_ON 1
>> +#define POWERNV_PHP_SLOT_ATTEN_IND 2
>> +#define POWERNV_PHP_SLOT_ATTEN_ACT 3
>> +
>> +struct powernv_php_slot {
>> + char *name;
>> + struct device_node *dn;
>> + struct pci_bus *bus;
>> + uint64_t id;
>> + int slot_no;
>> + struct kref kref;
>> +#define POWERNV_PHP_SLOT_STATE_INIT 0
>> +#define POWERNV_PHP_SLOT_STATE_REGISTER 1
>> +#define POWERNV_PHP_SLOT_STATE_POPULATED 2
>> + int state;
>> + int check_power_status;
>> + int status_confirmed;
>> + struct opal_msg *msg;
>> + uint64_t dt_counter;
>> + int overlay_id;
>> + struct work_struct work;
>> + wait_queue_head_t queue;
>> + struct hotplug_slot *php_slot;
>> + struct powernv_php_slot *parent;
>> + struct list_head children;
>> + struct list_head link;
>> +};
>> +
>> +int powernv_php_msg_handler(struct notifier_block *nb,
>> + unsigned long type, void *message);
>> +struct powernv_php_slot *powernv_php_slot_find(struct device_node *dn);
>> +void powernv_php_slot_free(struct kref *kref);
>> +struct powernv_php_slot *powernv_php_slot_alloc(struct device_node *dn);
>> +int powernv_php_slot_register(struct powernv_php_slot *slot);
>> +int powernv_php_slot_enable(struct hotplug_slot *php_slot, bool rescan);
>> +int powernv_php_register(struct device_node *dn);
>> +void powernv_php_unregister(struct device_node *dn);
>> +
>> +#define to_powernv_php_slot(kref) \
>> + container_of(kref, struct powernv_php_slot, kref)
>> +
>> +static inline void powernv_php_slot_get(struct powernv_php_slot *slot)
>> +{
>> + if (slot)
>> + kref_get(&slot->kref);
>> +}
>> +
>> +static inline int powernv_php_slot_put(struct powernv_php_slot *slot)
>> +{
>> + if (slot)
>> + return kref_put(&slot->kref, powernv_php_slot_free);
>> +
>> + return 0;
>> +}
>> +
>> +#endif /* !_POWERNV_PHP_H */
>> diff --git a/drivers/pci/hotplug/powernv_php_slot.c
>> b/drivers/pci/hotplug/powernv_php_slot.c
>> new file mode 100644
>> index 0000000..6c56455
>> --- /dev/null
>> +++ b/drivers/pci/hotplug/powernv_php_slot.c
>> @@ -0,0 +1,732 @@
>> +/*
>> + * PCI Hotplug Driver for PowerPC PowerNV platform.
>> + *
>> + * Copyright Gavin Shan, IBM Corporation 2015.
>> + *
>> + * 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.
>> + */
>> +
>> +#include <linux/module.h>
>> +
>> +#include <asm/opal.h>
>> +#include <asm/pnv-pci.h>
>> +#include <asm/ppc-pci.h>
>> +
>> +#include "powernv_php.h"
>> +
>> +static LIST_HEAD(php_slot_list);
>> +static DEFINE_SPINLOCK(php_slot_lock);
>> +
>> +/*
>> + * Remove firmware data for all child device nodes of the
>> + * indicated one.
>> + */
>> +static void remove_child_pdn(struct device_node *np)
>> +{
>> + struct device_node *child;
>> +
>> + for_each_child_of_node(np, child) {
>> + /* In depth first */
>> + remove_child_pdn(child);
>> +
>> + remove_pci_device_node_info(child);
>> + }
>> +}
>> +
>> +/*
>> + * Remove all subordinate device nodes of the indicated one.
>> + * Those device nodes in deepest path should be released firstly.
>> + */
>> +static int remove_child_device_nodes(struct device_node *parent)
>> +{
>> + struct device_node *np, *child;
>> + int ret = 0;
>> +
>> + /* If the device node has children, remove them firstly */
>> + for_each_child_of_node(parent, np) {
>> + ret = remove_child_device_nodes(np);
>> + if (ret)
>> + return ret;
>> +
>> + /* The device shouldn't have alive children */
>> + child = of_get_next_child(np, NULL);
>> + if (child) {
>> + of_node_put(child);
>> + of_node_put(np);
>> + pr_err("%s: Alive children of node <%s>\n",
>> + __func__, of_node_full_name(np));
>> + return -EBUSY;
>> + }
>> +
>> + /* Detach the device node */
>> + of_detach_node(np);
>> + of_node_put(np);
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +/*
>> + * The function processes the message sent by firmware
>> + * to remove all device tree nodes beneath the slot's
>> + * nodes, and the associated auxillary data.
>> + */
>> +static void slot_power_off_handler(struct powernv_php_slot *slot)
>> +{
>> + int ret;
>> +
>> + /* Release the firmware data for the child device nodes */
>> + remove_child_pdn(slot->dn);
>> +
>> + /*
>> + * Release the child device nodes. If the sub-tree was
>> + * built with the help of overlay, we just need revert
>> + * the changes introduced by the overlay
>> + */
>> + if (slot->overlay_id >= 0) {
>> + ret = of_overlay_destroy(slot->overlay_id);
>> + if (ret)
>> + pr_warn("%s: Error %d destroying overlay %d\n",
>> + __func__, ret, slot->overlay_id);
>> + slot->overlay_id = -1;
>> + } else {
>> + ret = remove_child_device_nodes(slot->dn);
>> + if (ret)
>> + pr_warn("%s: Error %d releasing children of <%s>\n",
>> + __func__, ret, of_node_full_name(slot->dn));
>> + }
>> +
>> + /* Confirm status change */
>> + slot->status_confirmed = 1;
>> + wake_up_interruptible(&slot->queue);
>> +}
>> +
>> +static void slot_power_on_handler(struct powernv_php_slot *slot)
>> +{
>> + struct device_node *nodes[3] = {NULL, NULL, NULL};
>> + struct property *prop = NULL;
>> + void *fdt = NULL, *dt = NULL;
>> + phandle handle;
>> + uint64_t len;
>> + int i, ret;
>> +
>> + /* Build overlay sub-tree */
>> + for (i = 0; i < ARRAY_SIZE(nodes); i++) {
>> + nodes[i] = kzalloc(sizeof(struct device_node), GFP_KERNEL);
>> + if (!nodes[i])
>> + goto out;
>> +
>> + of_node_init(nodes[i]);
>> + if (i > 0) {
>> + nodes[i - 1]->child = nodes[i];
>> + nodes[i]->parent = nodes[i - 1];
>> + }
>> + }
>> +
>> + /* Target property for parent node */
>> + prop = kzalloc(sizeof(struct property), GFP_KERNEL);
>> + if (!prop)
>> + goto out;
>> + prop->name = kstrdup("target", GFP_KERNEL);
>> + if (!prop->name)
>> + goto out;
>> + prop->value = kzalloc(sizeof(phandle), GFP_KERNEL);
>> + if (!prop->value)
>> + goto out;
>> + handle = cpu_to_be32(slot->dn->phandle);
>> + memcpy(prop->value, &handle, sizeof(phandle));
>> + prop->length = sizeof(phandle);
>> + nodes[1]->properties = prop;
>> +
>> + /* Names for overlay node */
>> + nodes[2]->name = kstrdup("__overlay__", GFP_KERNEL);
>> + if (!nodes[2]->name)
>> + goto out;
>> + nodes[2]->full_name = kstrdup(of_node_full_name(slot->dn), GFP_KERNEL);
>> + if (!nodes[2]->full_name)
>> + goto out;
>
>I think you can simplify this driver by using the of_changeset api
>instead of of_overlay. of_overlay is a particular data format passed
>into the kernel, but it uses of_changeset in the back end. In this case,
>you would allocate an of_changeset structure and then do:
>
>of_changeset_init()
>of_changeset_attach_node()
> /* you might need to create an
> * of_changeset_attach_node_subtree() varient */
>of_changeset_attach_node()
>of_changeset_attach_node()
>of_changeset_attach_node()
>of_changeset_apply()
>of_changeset_destroy() /* frees the structure */
>
>Then you don't have to muck about with creating a DT in the structure
>expected by the of_overlay code.
>
Yeah, Thanks for the suggestion, Grant. I'm waiting for a usable
4.2.rc1 and integrate the comments I received, then post the new
revision. The changes to use changeset will be included in next
revision.
Thanks,
Gavin
>> +
>> + /* Get FDT blob */
>> + slot->dt_counter += 1;
>> + fdt = NULL;
>> + len = 0x2000;
>> + while (len <= 0x10000) {
>> + fdt = kzalloc(len, GFP_KERNEL);
>> + if (!fdt)
>> + break;
>> +
>> + ret = pnv_pci_get_overlay_dt(&slot->dt_counter, fdt, len);
>> + if (!ret)
>> + break;
>> +
>> + kfree(fdt);
>> + fdt = NULL;
>> + len *= 2;
>> + }
>> +
>> + if (!fdt)
>> + goto out;
>> +
>> + /* Unflatten device tree blob */
>> + dt = of_fdt_unflatten_tree(fdt, nodes[2], NULL);
>> +
>> + /* Apply the overlay tree */
>> + slot->overlay_id = of_overlay_create(nodes[0]);
>> + if (slot->overlay_id < 0)
>> + goto out;
>> +
>> + /* Add device node firmware data */
>> + traverse_pci_device_nodes(slot->dn,
>> + add_pci_device_node_info,
>> + pci_bus_to_host(slot->bus));
>> +
>> +out:
>> + kfree(dt);
>> + kfree(fdt);
>> + if (nodes[2]) {
>> + kfree(nodes[2]->name);
>> + kfree(nodes[2]->full_name);
>> + }
>> + if (prop) {
>> + kfree(prop->value);
>> + kfree(prop->name);
>> + }
>> +
>> + kfree(prop);
>> + for (i = 0; i < ARRAY_SIZE(nodes); i++)
>> + kfree(nodes[i]);
>> +
>> + /* Confirm status change */
>> + slot->status_confirmed = 1;
>> + wake_up_interruptible(&slot->queue);
>> +}
>> +
>> +static void powernv_php_slot_work(struct work_struct *data)
>> +{
>> + struct powernv_php_slot *slot = container_of(data,
>> + struct powernv_php_slot,
>> + work);
>> + uint64_t php_event = be64_to_cpu(slot->msg->params[0]);
>> +
>> + switch (php_event) {
>> + case 0: /* Slot power off */
>> + slot_power_off_handler(slot);
>> + break;
>> + case 1: /* Slot power on */
>> + slot_power_on_handler(slot);
>> + break;
>> + default:
>> + pr_warn("%s: Unsupported hotplug event %lld\n",
>> + __func__, php_event);
>> + }
>> +
>> + of_node_put(slot->dn);
>> +}
>> +
>> +int powernv_php_msg_handler(struct notifier_block *nb,
>> + unsigned long type, void *message)
>> +{
>> + phandle h;
>> + struct device_node *np;
>> + struct powernv_php_slot *slot;
>> + struct opal_msg *msg = message;
>> +
>> + /* Check the message type */
>> + if (type != OPAL_MSG_PCI_HOTPLUG) {
>> + pr_warn("%s: Wrong message type %ld received!\n",
>> + __func__, type);
>> + return NOTIFY_DONE;
>> + }
>> +
>> + /* Find the device node */
>> + h = (phandle)be64_to_cpu(msg->params[1]);
>> + np = of_find_node_by_phandle(h);
>> + if (!np) {
>> + pr_warn("%s: No device node for phandle 0x%08x\n",
>> + __func__, h);
>> + return NOTIFY_DONE;
>> + }
>> +
>> + /* Find the slot */
>> + slot = powernv_php_slot_find(np);
>> + if (!slot) {
>> + pr_warn("%s: No slot found for node <%s>\n",
>> + __func__, of_node_full_name(np));
>> + of_node_put(np);
>> + return NOTIFY_DONE;
>> + }
>> +
>> + /* Schedule the work */
>> + slot->msg = msg;
>> + schedule_work(&slot->work);
>> + return NOTIFY_OK;
>> +}
>> +
>> +static int set_power_status(struct hotplug_slot *php_slot, u8 val)
>> +{
>> + struct powernv_php_slot *slot = php_slot->private;
>> + int ret;
>> +
>> + /* Retrieve the counter of device tree */
>> + ret = pnv_pci_get_overlay_dt(&slot->dt_counter, NULL, 0);
>> + if (ret) {
>> + pr_warn("%s: Error %d getting DT counter for slot %016llx\n",
>> + __func__, ret, slot->id);
>> + return ret;
>> + }
>> +
>> + /* Set power status */
>> + slot->status_confirmed = 0;
>> + ret = pnv_pci_set_power_status(slot->id, val);
>> + if (ret) {
>> + pr_warn("%s: Error %d powering %s slot %016llx\n",
>> + __func__, ret, val ? "on" : "off", slot->id);
>> + return ret;
>> + }
>> +
>> + /* Waiting until the device tree is updated */
>> + ret = wait_event_timeout(slot->queue,
>> + !slot->status_confirmed,
>> + 10 * HZ);
>> + if (ret) {
>> + pr_warn("%s: Error %d completing power-%s slot %016llx\n",
>> + __func__, ret, val ? "on" : "off", slot->id);
>> + return ret;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static int get_power_status(struct hotplug_slot *php_slot, u8 *val)
>> +{
>> + struct powernv_php_slot *slot = php_slot->private;
>> + uint8_t state;
>> + int ret;
>> +
>> + /*
>> + * Retrieve power status from firmware. If we fail
>> + * getting that, the power status fails back to
>> + * be on.
>> + */
>> + ret = pnv_pci_get_power_status(slot->id, &state);
>> + if (ret) {
>> + *val = POWERNV_PHP_SLOT_POWER_ON;
>> + pr_warn("%s: Error %d getting power status of slot %016llx\n",
>> + __func__, ret, slot->id);
>> + } else {
>> + *val = state ? POWERNV_PHP_SLOT_POWER_ON :
>> + POWERNV_PHP_SLOT_POWER_OFF;
>> + php_slot->info->power_status = *val;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static int get_adapter_status(struct hotplug_slot *php_slot, u8 *val)
>> +{
>> + struct powernv_php_slot *slot = php_slot->private;
>> + uint8_t state;
>> + int ret;
>> +
>> + /*
>> + * Retrieve presence status from firmware. If we can't
>> + * get that, it will fail back to be empty.
>> + */
>> + ret = pnv_pci_get_presence_status(slot->id, &state);
>> + if (ret >= 0) {
>> + ret = 0;
>> + *val = state ? POWERNV_PHP_SLOT_PRESENT :
>> + POWERNV_PHP_SLOT_EMPTY;
>> + php_slot->info->adapter_status = *val;
>> + ret = 0;
>> + } else {
>> + *val = POWERNV_PHP_SLOT_EMPTY;
>> + pr_warn("%s: Error %d getting presence of slot %016llx\n",
>> + __func__, ret, slot->id);
>> + }
>> +
>> + return ret;
>> +}
>> +
>> +static int set_attention_status(struct hotplug_slot *php_slot, u8 val)
>> +{
>> + /* The default operation would to turn on the attention */
>> + switch (val) {
>> + case POWERNV_PHP_SLOT_ATTEN_OFF:
>> + case POWERNV_PHP_SLOT_ATTEN_ON:
>> + case POWERNV_PHP_SLOT_ATTEN_IND:
>> + case POWERNV_PHP_SLOT_ATTEN_ACT:
>> + break;
>> + default:
>> + pr_warn("%s: Invalid attention status 0x%02x\n",
>> + __func__, val);
>> + return -EINVAL;
>> + }
>> +
>> + /* FIXME: Make it real once firmware supports it */
>> + php_slot->info->attention_status = val;
>> +
>> + return 0;
>> +}
>> +
>> +int powernv_php_slot_enable(struct hotplug_slot *php_slot, bool rescan)
>> +{
>> + struct powernv_php_slot *slot = php_slot->private;
>> + uint8_t presence, power_status;
>> + int ret;
>> +
>> + /* Check if the slot has been configured */
>> + if (slot->state != POWERNV_PHP_SLOT_STATE_REGISTER)
>> + return 0;
>> +
>> + /* Retrieve slot presence status */
>> + ret = php_slot->ops->get_adapter_status(php_slot, &presence);
>> + if (ret) {
>> + pr_warn("%s: Error %d getting presence of slot %016llx\n",
>> + __func__, ret, slot->id);
>> + return ret;
>> + }
>> +
>> + /* Proceed if there have nothing behind the slot */
>> + if (presence == POWERNV_PHP_SLOT_EMPTY)
>> + goto scan;
>> +
>> + /*
>> + * If we don't detect something behind the slot, we need
>> + * make sure the power suply to the slot is on. Otherwise,
>> + * the slot downstream PCIe linkturn should be down.
>> + *
>> + * 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 (!slot->check_power_status) {
>> + slot->check_power_status = 1;
>> + goto scan;
>> + }
>> +
>> + /* Check the power status. Scan the slot if that's already on */
>> + ret = php_slot->ops->get_power_status(php_slot, &power_status);
>> + if (ret) {
>> + pr_warn("%s: Error %d getting power status of slot %016llx\n",
>> + __func__, ret, slot->id);
>> + return ret;
>> + }
>> + if (power_status == POWERNV_PHP_SLOT_POWER_ON)
>> + goto scan;
>> +
>> + /* Power is off, turn it on and then scan the slot */
>> + ret = set_power_status(php_slot, POWERNV_PHP_SLOT_POWER_ON);
>> + if (ret) {
>> + pr_warn("%s: Error %d powering on slot %016llx\n",
>> + __func__, ret, slot->id);
>> + return ret;
>> + }
>> +
>> +scan:
>> + switch (presence) {
>> + case POWERNV_PHP_SLOT_PRESENT:
>> + if (rescan) {
>> + pci_lock_rescan_remove();
>> + pcibios_add_pci_devices(slot->bus);
>> + pci_unlock_rescan_remove();
>> + }
>> +
>> + /* Rescan for child hotpluggable slots */
>> + slot->state = POWERNV_PHP_SLOT_STATE_POPULATED;
>> + if (rescan)
>> + powernv_php_register(slot->dn);
>> + break;
>> + case POWERNV_PHP_SLOT_EMPTY:
>> + slot->state = POWERNV_PHP_SLOT_STATE_POPULATED;
>> + break;
>> + default:
>> + pr_warn("%s: Invalid presence status %d of slot %016llx\n",
>> + __func__, presence, slot->id);
>> + return -EINVAL;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static int enable_slot(struct hotplug_slot *php_slot)
>> +{
>> + return powernv_php_slot_enable(php_slot, true);
>> +}
>> +
>> +static int disable_slot(struct hotplug_slot *php_slot)
>> +{
>> + struct powernv_php_slot *slot = php_slot->private;
>> + uint8_t power_status;
>> + int ret;
>> +
>> + if (slot->state != POWERNV_PHP_SLOT_STATE_POPULATED)
>> + return 0;
>> +
>> + /* Remove all devices behind the slot */
>> + pci_lock_rescan_remove();
>> + pcibios_remove_pci_devices(slot->bus);
>> + pci_unlock_rescan_remove();
>> +
>> + /* Detach the child hotpluggable slots */
>> + powernv_php_unregister(slot->dn);
>> +
>> + /*
>> + * Check the power status and turn it off if necessary. If we
>> + * fail to get the power status, the power will be forced to
>> + * be off.
>> + */
>> + ret = php_slot->ops->get_power_status(php_slot, &power_status);
>> + if (ret || power_status == POWERNV_PHP_SLOT_POWER_ON) {
>> + ret = set_power_status(php_slot, POWERNV_PHP_SLOT_POWER_OFF);
>> + if (ret)
>> + pr_warn("%s: Error %d powering off slot %016llx\n",
>> + __func__, ret, slot->id);
>> + }
>> +
>> + /* Update slot state */
>> + slot->state = POWERNV_PHP_SLOT_STATE_REGISTER;
>> + return 0;
>> +}
>> +
>> +static struct hotplug_slot_ops php_slot_ops = {
>> + .get_power_status = get_power_status,
>> + .get_adapter_status = get_adapter_status,
>> + .set_attention_status = set_attention_status,
>> + .enable_slot = enable_slot,
>> + .disable_slot = disable_slot,
>> +};
>> +
>> +static struct powernv_php_slot *php_slot_match(struct device_node *dn,
>> + struct powernv_php_slot *slot)
>> +{
>> + struct powernv_php_slot *target, *tmp;
>> +
>> + if (slot->dn == dn)
>> + return slot;
>> +
>> + list_for_each_entry(tmp, &slot->children, link) {
>> + target = php_slot_match(dn, tmp);
>> + if (target)
>> + return target;
>> + }
>> +
>> + return NULL;
>> +}
>> +
>> +struct powernv_php_slot *powernv_php_slot_find(struct device_node *dn)
>> +{
>> + struct powernv_php_slot *slot, *tmp;
>> + unsigned long flags;
>> +
>> + spin_lock_irqsave(&php_slot_lock, flags);
>> + list_for_each_entry(tmp, &php_slot_list, link) {
>> + slot = php_slot_match(dn, tmp);
>> + if (slot) {
>> + spin_unlock_irqrestore(&php_slot_lock, flags);
>> + return slot;
>> + }
>> + }
>> + spin_unlock_irqrestore(&php_slot_lock, flags);
>> +
>> + return NULL;
>> +}
>> +
>> +void powernv_php_slot_free(struct kref *kref)
>> +{
>> + struct powernv_php_slot *slot = to_powernv_php_slot(kref);
>> +
>> + WARN_ON(!list_empty(&slot->children));
>> + kfree(slot->name);
>> + kfree(slot);
>> +}
>> +
>> +static void php_slot_release(struct hotplug_slot *hp_slot)
>> +{
>> + struct powernv_php_slot *slot = hp_slot->private;
>> + unsigned long flags;
>> +
>> + /* Remove from global or child list */
>> + spin_lock_irqsave(&php_slot_lock, flags);
>> + list_del(&slot->link);
>> + spin_unlock_irqrestore(&php_slot_lock, flags);
>> +
>> + /* Detach from parent */
>> + powernv_php_slot_put(slot);
>> + powernv_php_slot_put(slot->parent);
>> +}
>> +
>> +static bool php_slot_get_id(struct device_node *dn,
>> + uint64_t *id)
>> +{
>> + struct device_node *parent = dn;
>> + const __be64 *prop64;
>> + const __be32 *prop32;
>> +
>> + /*
>> + * The hotpluggable slot always has a compound Id, which
>> + * consists of 16-bits PHB Id, 16 bits bus/slot/function
>> + * number, and compound indicator
>> + */
>> + *id = (0x1ul << 63);
>> +
>> + /* Bus/Slot/Function number */
>> + prop32 = of_get_property(dn, "reg", NULL);
>> + if (!prop32)
>> + return false;
>> + *id |= ((of_read_number(prop32, 1) & 0x00ffff00) << 8);
>> +
>> + /* PHB Id */
>> + while ((parent = of_get_parent(parent))) {
>> + if (!PCI_DN(parent)) {
>> + of_node_put(parent);
>> + break;
>> + }
>> +
>> + if (!of_device_is_compatible(parent, "ibm,ioda2-phb") &&
>> + !of_device_is_compatible(parent, "ibm,ioda-phb")) {
>> + of_node_put(parent);
>> + continue;
>> + }
>> +
>> + prop64 = of_get_property(parent, "ibm,opal-phbid", NULL);
>> + if (!prop64) {
>> + of_node_put(parent);
>> + return false;
>> + }
>> +
>> + *id |= be64_to_cpup(prop64);
>> + of_node_put(parent);
>> + return true;
>> + }
>> +
>> + return false;
>> +}
>> +
>> +struct powernv_php_slot *powernv_php_slot_alloc(struct device_node *dn)
>> +{
>> + struct pci_bus *bus;
>> + struct powernv_php_slot *slot;
>> + const char *label;
>> + uint64_t id;
>> + int slot_no;
>> + size_t size;
>> + void *pmem;
>> +
>> + /* Slot name */
>> + label = of_get_property(dn, "ibm,slot-label", NULL);
>> + if (!label)
>> + return NULL;
>> +
>> + /* Slot indentifier */
>> + if (!php_slot_get_id(dn, &id))
>> + return NULL;
>> +
>> + /* PCI bus */
>> + bus = pcibios_find_pci_bus(dn);
>> + if (!bus)
>> + return NULL;
>> +
>> + /* Slot number */
>> + if (dn->child && PCI_DN(dn->child))
>> + slot_no = PCI_SLOT(PCI_DN(dn->child)->devfn);
>> + else
>> + slot_no = -1;
>> +
>> + /* Allocate slot */
>> + size = sizeof(struct powernv_php_slot) +
>> + sizeof(struct hotplug_slot) +
>> + sizeof(struct hotplug_slot_info);
>> + pmem = kzalloc(size, GFP_KERNEL);
>> + if (!pmem) {
>> + pr_warn("%s: Cannot allocate slot for node %s\n",
>> + __func__, dn->full_name);
>> + return NULL;
>> + }
>> +
>> + /* Assign memory blocks */
>> + slot = pmem;
>> + slot->php_slot = pmem + sizeof(struct powernv_php_slot);
>> + slot->php_slot->info = pmem + sizeof(struct powernv_php_slot) +
>> + sizeof(struct hotplug_slot);
>> + slot->name = kstrdup(label, GFP_KERNEL);
>> + if (!slot->name) {
>> + pr_warn("%s: Cannot populate name for node %s\n",
>> + __func__, dn->full_name);
>> + kfree(pmem);
>> + return NULL;
>> + }
>> +
>> + /* Initialize slot */
>> + kref_init(&slot->kref);
>> + slot->state = POWERNV_PHP_SLOT_STATE_INIT;
>> + slot->dn = dn;
>> + slot->bus = bus;
>> + slot->id = id;
>> + slot->slot_no = slot_no;
>> + slot->overlay_id = -1;
>> + INIT_WORK(&slot->work, powernv_php_slot_work);
>> + init_waitqueue_head(&slot->queue);
>> + slot->check_power_status = 0;
>> + slot->status_confirmed = 0;
>> + slot->php_slot->ops = &php_slot_ops;
>> + slot->php_slot->release = php_slot_release;
>> + slot->php_slot->private = slot;
>> + INIT_LIST_HEAD(&slot->children);
>> + INIT_LIST_HEAD(&slot->link);
>> +
>> + return slot;
>> +}
>> +
>> +int powernv_php_slot_register(struct powernv_php_slot *slot)
>> +{
>> + struct powernv_php_slot *parent;
>> + struct device_node *dn = slot->dn;
>> + unsigned long flags;
>> + int ret;
>> +
>> + /* Avoid register same slot for twice */
>> + if (powernv_php_slot_find(slot->dn))
>> + return -EEXIST;
>> +
>> + /* Register slot */
>> + ret = pci_hp_register(slot->php_slot, slot->bus,
>> + slot->slot_no, slot->name);
>> + if (ret) {
>> + pr_warn("%s: Cannot register slot %s (%d)\n",
>> + __func__, slot->name, ret);
>> + return ret;
>> + }
>> +
>> + /* Put into global or parent list */
>> + while ((dn = of_get_parent(dn))) {
>> + if (!PCI_DN(dn)) {
>> + of_node_put(dn);
>> + break;
>> + }
>> +
>> + parent = powernv_php_slot_find(dn);
>> + if (parent) {
>> + of_node_put(dn);
>> + break;
>> + }
>> + }
>> +
>> + spin_lock_irqsave(&php_slot_lock, flags);
>> + if (parent) {
>> + powernv_php_slot_get(parent);
>> + slot->parent = parent;
>> + list_add_tail(&slot->link, &parent->children);
>> + } else {
>> + list_add_tail(&slot->link, &php_slot_list);
>> + }
>> + spin_unlock_irqrestore(&php_slot_lock, flags);
>> +
>> + /* Update slot state */
>> + slot->state = POWERNV_PHP_SLOT_STATE_REGISTER;
>> + return 0;
>> +}
>> --
>> 2.1.0
>>
>
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