On Thu, 4 Jun 2015 16:42:11 +1000
, Gavin Shan <[email protected]>
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 <[email protected]>
> ---
> 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: [email protected]
> S: Supported
> F: Documentation/PCI/pci-error-recovery.txt
>
> +PCI HOTPLUG DRIVER FOR POWERNV PLATFORM
> +M: Gavin Shan <[email protected]>
> +L: [email protected]
> +S: Supported
> +F: drivers/pci/hotplug/powernv_php*
> +
> PCI SUBSYSTEM
> M: Bjorn Helgaas <[email protected]>
> L: [email protected]
> 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.
> +
> + /* 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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