[PATCH v8 45/45] PCI/hotplug: PowerPC PowerNV PCI hotplug driver
Alexey Kardashevskiy
aik at ozlabs.ru
Mon May 2 16:11:53 AEST 2016
On 05/02/2016 01:44 PM, Gavin Shan wrote:
> On Tue, Apr 19, 2016 at 08:36:48PM +1000, Alexey Kardashevskiy wrote:
>> On 02/17/2016 02:44 PM, Gavin Shan wrote:
>>> This adds standalone driver to support PCI hotplug for PowerPC PowerNV
>>> platform that runs on top of skiboot firmware. The firmware identifies
>>> hotpluggable slots and marked their device tree node with proper
>>> "ibm,slot-pluggable" and "ibm,reset-by-firmware". The driver scans
>>> device tree nodes to create/register PCI hotplug slot accordingly.
>>>
>>> The PCI slots are organized in fashion of tree, which means one
>>> PCI slot might have parent PCI slot and parent PCI slot possibly
>>> contains multiple child PCI slots. At the plugging time, the parent
>>> PCI slot is populated before its children. The child PCI slots are
>>> removed before their parent PCI slot can be removed from the system.
>>>
>>> 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 <gwshan at linux.vnet.ibm.com>
>>> Acked-by: Bjorn Helgaas <bhelgaas at google.com>
>>> ---
>>> drivers/pci/hotplug/Kconfig | 12 +
>>> drivers/pci/hotplug/Makefile | 3 +
>>> drivers/pci/hotplug/pnv_php.c | 870 ++++++++++++++++++++++++++++++++++++++++++
>>> 3 files changed, 885 insertions(+)
>>> create mode 100644 drivers/pci/hotplug/pnv_php.c
>>>
>>> diff --git a/drivers/pci/hotplug/Kconfig b/drivers/pci/hotplug/Kconfig
>>> index df8caec..167c8ce 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 pnv-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 b616e75..e33cdda 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-$(CONFIG_HOTPLUG_PCI_POWERNV) += pnv-php.o
>>> obj-$(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 +51,8 @@ ibmphp-objs := ibmphp_core.o \
>>> acpiphp-objs := acpiphp_core.o \
>>> acpiphp_glue.o
>>>
>>> +pnv-php-objs := pnv_php.o
>>> +
>>> rpaphp-objs := rpaphp_core.o \
>>> rpaphp_pci.o \
>>> rpaphp_slot.o
>>> diff --git a/drivers/pci/hotplug/pnv_php.c b/drivers/pci/hotplug/pnv_php.c
>>> new file mode 100644
>>> index 0000000..364ec36
>>> --- /dev/null
>>> +++ b/drivers/pci/hotplug/pnv_php.c
>>> @@ -0,0 +1,870 @@
>>> +/*
>>> + * 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/libfdt.h>
>>> +#include <linux/module.h>
>>> +#include <linux/pci.h>
>>> +#include <linux/pci_hotplug.h>
>>> +
>>> +#include <asm/opal.h>
>>> +#include <asm/pnv-pci.h>
>>> +#include <asm/ppc-pci.h>
>>> +
>>> +#define DRIVER_VERSION "0.1"
>>> +#define DRIVER_AUTHOR "Gavin Shan, IBM Corporation"
>>> +#define DRIVER_DESC "PowerPC PowerNV PCI Hotplug Driver"
>>> +
>>> +struct pnv_php_slot {
>>> + struct hotplug_slot slot;
>>> + struct hotplug_slot_info slot_info;
>>> + uint64_t id;
>>> + char *name;
>>> + int slot_no;
>>> + struct kref kref;
>>> +#define PNV_PHP_STATE_INITIALIZED 0
>>> +#define PNV_PHP_STATE_REGISTERED 1
>>> +#define PNV_PHP_STATE_POPULATED 2
>>> + int state;
>>> + struct device_node *dn;
>>> + struct pci_dev *pdev;
>>> + struct pci_bus *bus;
>>> + bool power_state_check;
>>> + int power_state_confirmed;
>>> +#define PNV_PHP_POWER_CONFIRMED_INVALID 0
>>> +#define PNV_PHP_POWER_CONFIRMED_SUCCESS 1
>>> +#define PNV_PHP_POWER_CONFIRMED_FAIL 2
>>> + struct opal_msg *msg;
>>> + void *fdt;
>>> + void *dt;
>>> + struct of_changeset ocs;
>>> + struct work_struct work;
>>> + wait_queue_head_t queue;
>>> + struct pnv_php_slot *parent;
>>> + struct list_head children;
>>> + struct list_head link;
>>> +};
>>> +
>>> +static LIST_HEAD(pnv_php_slot_list);
>>> +static DEFINE_SPINLOCK(pnv_php_lock);
>>> +
>>> +static void pnv_php_register(struct device_node *dn);
>>> +static void pnv_php_unregister_one(struct device_node *dn);
>>> +static void pnv_php_unregister(struct device_node *dn);
>>
>>
>> The names confused me. I'd suggest pnv_php_scan(), pnv_php_unregister(),
>> pnv_php_unregister_children() instead.
>>
>>
>> Alistair, what do you reckon?
>>
>>
>>> +
>>> +static void pnv_php_free_slot(struct kref *kref)
>>> +{
>>> + struct pnv_php_slot *php_slot = container_of(kref,
>>> + struct pnv_php_slot,
>>> + kref);
>>> +
>>> + WARN_ON(!list_empty(&php_slot->children));
>>> + kfree(php_slot->name);
>>> + kfree(php_slot);
>>> +}
>>> +
>>> +static inline void pnv_php_put_slot(struct pnv_php_slot *php_slot)
>>> +{
>>> + if (!php_slot)
>>
>>
>> BUG_ON()?
>>
>
> checkpatch.pl will report warning like below. Are you sure you need a BUG_ON()?
No, I am not - this is why I asked. How possible is it to have here
phb_slot==NULL? Can we recover from that? The options are -
1) memory is corrupted (then we cannot and it has to be BUG_ON)
2) broken/old OPAL returns unexpected error (then we can continue, I guess)
3) there are ways (via sysfs in the userspace? no idea) to get
pnv_php_put_slot() called with phb_slot.
If only 1) is possible - then BUG_ON, if 2) - WARN_ON, if 3) - should be
neither BUG_ON nor WARN_ON. You know the code better, you decide.
>
> WARNING: Avoid crashing the kernel - try using WARN_ON & recovery code rather than BUG() or BUG_ON()
> #159: FILE: drivers/pci/hotplug/pnv_php.c:76:
> + BUG_ON(!php_slot);
>
>
>>> + return;
>>> +
>>> + kref_put(&php_slot->kref, pnv_php_free_slot);
>>> +}
>>> +
>>> +static struct pnv_php_slot *pnv_php_match(struct device_node *dn,
>>> + struct pnv_php_slot *php_slot)
>>> +{
>>> + struct pnv_php_slot *target, *tmp;
>>> +
>>> + if (php_slot->dn == dn) {
>>> + kref_get(&php_slot->kref);
>>> + return php_slot;
>>> + }
>>> +
>>> + list_for_each_entry(tmp, &php_slot->children, link) {
>>> + target = pnv_php_match(dn, tmp);
>>> + if (target)
>>> + return target;
>>> + }
>>> +
>>> + return NULL;
>>> +}
>>> +
>>> +static struct pnv_php_slot *pnv_php_find_slot(struct device_node *dn)
>>> +{
>>> + struct pnv_php_slot *php_slot, *tmp;
>>> + unsigned long flags;
>>> +
>>> + spin_lock_irqsave(&pnv_php_lock, flags);
>>> + list_for_each_entry(tmp, &pnv_php_slot_list, link) {
>>> + php_slot = pnv_php_match(dn, tmp);
>>> + if (php_slot) {
>>> + spin_unlock_irqrestore(&pnv_php_lock, flags);
>>> + return php_slot;
>>> + }
>>> + }
>>> + spin_unlock_irqrestore(&pnv_php_lock, flags);
>>> +
>>> + return NULL;
>>> +}
>>> +
>>> +/*
>>> + * Remove pdn for all children of the indicated device node.
>>> + * The function should remove pdn in a depth-first manner.
>>> + */
>>> +static void pnv_php_rmv_pdns(struct device_node *dn)
>>> +{
>>> + struct device_node *child;
>>> +
>>> + for_each_child_of_node(dn, child) {
>>> + pnv_php_rmv_pdns(child);
>>> +
>>> + pci_remove_device_node_info(child);
>>> + }
>>> +}
>>> +
>>> +/*
>>> + * Remove all child nodes of the indicated device nodes. The
>>> + * function should remove device nodes in depth-first manner.
>>> + */
>>> +static int pnv_php_rmv_device_nodes(struct device_node *parent)
>>> +{
>>> + struct device_node *dn, *child;
>>> + int ret = 0;
>>> +
>>> + for_each_child_of_node(parent, dn) {
>>> + ret = pnv_php_rmv_device_nodes(dn);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + child = of_get_next_child(dn, NULL);
>>> + if (child) {
>>> + of_node_put(child);
>>> + of_node_put(dn);
>>> + pr_err("%s: Alive children of node <%s>\n",
>>> + __func__, of_node_full_name(dn));
>>> + return -EBUSY;
>>> + }
>>> +
>>> + of_detach_node(dn);
While playing with compiler options, I hit this:
MODPOST 248 modules
ERROR: "of_detach_node" [drivers/pci/hotplug/pnv-php.ko] undefined!
/home/aik/p/kernel-power8hp/scripts/Makefile.modpost:91: recipe for target
'__modpost' failed
make[2]: *** [__modpost] Error 1
I enabled pnv-php to compile as a module:
CONFIG_HOTPLUG_PCI_POWERNV=m
This is missing:
diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
index c647bd1..75ce30d 100644
--- a/drivers/of/dynamic.c
+++ b/drivers/of/dynamic.c
@@ -311,6 +311,7 @@ int of_detach_node(struct device_node *np)
return rc;
}
+EXPORT_SYMBOL_GPL(of_detach_node);
>>> + of_node_put(dn);
>>> + }
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +/*
>>> + * The function processes the message sent by firmware
>>> + * to remove all device tree nodes beneath the slot's
>>> + * nodes and the associated auxiliary data.
>>> + */
>>> +static void pnv_php_handle_poweroff(struct pnv_php_slot *php_slot)
>>> +{
>>> + int ret;
>>> +
>>> + pnv_php_rmv_pdns(php_slot->dn);
>>> +
>>> + /*
>>> + * If the device sub-tree was created from OF changeset, simply
>>> + * to revert that. Otherwise, the device nodes in the sub-tree
>>> + * need to be iterated and detached.
>>> + */
>>> + if (php_slot->fdt) {
>>> + of_changeset_destroy(&php_slot->ocs);
>>> + kfree(php_slot->dt);
>>> + kfree(php_slot->fdt);
>>> + php_slot->dt = NULL;
>>> + php_slot->dn->child = NULL;
>>> + php_slot->fdt = NULL;
>>> + php_slot->power_state_confirmed =
>>> + PNV_PHP_POWER_CONFIRMED_SUCCESS;
>>> + wake_up_interruptible(&php_slot->queue);
>>> + return;
>>> + }
>>> +
>>> + ret = pnv_php_rmv_device_nodes(php_slot->dn);
>>> + if (!ret) {
>>> + php_slot->power_state_confirmed =
>>> + PNV_PHP_POWER_CONFIRMED_SUCCESS;
>>> + } else {
>>> + php_slot->power_state_confirmed = PNV_PHP_POWER_CONFIRMED_FAIL;
>>> + dev_warn(&php_slot->pdev->dev, "Error %d freeing nodes\n", ret);
>>> + }
>>> +
>>> + wake_up_interruptible(&php_slot->queue);
>>
>>
>> I liked one wake_up_interruptible() better...
>>
>
> Will fix in next revision.
>
>>> +}
>>> +
>>> +static int pnv_php_populate_changeset(struct of_changeset *ocs,
>>> + struct device_node *dn)
>>> +{
>>> + struct device_node *child;
>>> + int ret = 0;
>>> +
>>> + for_each_child_of_node(dn, child) {
>>> + ret = of_changeset_attach_node(ocs, child);
>>> + if (ret)
>>> + break;
>>> +
>>> + ret = pnv_php_populate_changeset(ocs, child);
>>
>>
>> I asked in v7 - may be to add here "if (ret) break;"?
>>
>
> Will add it in v9.
>
>>> + }
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +static void *pnv_php_add_one_pdn(struct device_node *dn, void *data)
>>> +{
>>> + struct pci_controller *hose = (struct pci_controller *)data;
>>> + struct pci_dn *pdn;
>>> +
>>> + pdn = pci_add_device_node_info(hose, dn);
>>> + if (!pdn)
>>> + return ERR_PTR(-ENOMEM);
>>> +
>>> + return NULL;
>>> +}
>>> +
>>> +static void pnv_php_add_pdns(struct pnv_php_slot *slot)
>>> +{
>>> + struct pci_controller *hose = pci_bus_to_host(slot->bus);
>>> +
>>> + pci_traverse_device_nodes(slot->dn, pnv_php_add_one_pdn, hose);
>>> +}
>>> +
>>> +static void pnv_php_handle_poweron(struct pnv_php_slot *php_slot)
>>> +{
>>> + void *fdt, *fdt1, *dt;
>>> + int confirm = PNV_PHP_POWER_CONFIRMED_SUCCESS;
>>> + int ret;
>>> +
>>> + /* We don't know the FDT blob size. We try to get it through
>>> + * maximal memory chunk and then copy it to another chunk that
>>> + * fits the real size.
>>> + */
>>> + fdt1 = kzalloc(0x10000, GFP_KERNEL);
>>> + if (!fdt1)
>>> + goto error;
>>> +
>>> + ret = pnv_pci_get_device_tree(php_slot->dn->phandle, fdt1, 0x10000);
>>> + if (ret)
>>> + goto free_fdt1;
>>> +
>>> + fdt = kzalloc(fdt_totalsize(fdt1), GFP_KERNEL);
>>> + if (!fdt)
>>> + goto free_fdt1;
>>> +
>>> + /* Unflatten device tree blob */
>>> + memcpy(fdt, fdt1, fdt_totalsize(fdt1));
>>> + dt = of_fdt_unflatten_tree(fdt, php_slot->dn, NULL);
>>> + if (!dt) {
>>> + dev_warn(&php_slot->pdev->dev, "Cannot unflatten FDT\n");
>>> + goto free_fdt;
>>> + }
>>> +
>>> + /* Initialize and apply the changeset */
>>> + of_changeset_init(&php_slot->ocs);
>>> + ret = pnv_php_populate_changeset(&php_slot->ocs, php_slot->dn);
>>> + if (ret) {
>>> + dev_warn(&php_slot->pdev->dev, "Error %d populating changeset\n",
>>> + ret);
>>> + goto free_dt;
>>> + }
>>> +
>>> + php_slot->dn->child = NULL;
>>> + ret = of_changeset_apply(&php_slot->ocs);
>>> + if (ret) {
>>> + dev_warn(&php_slot->pdev->dev, "Error %d applying changeset\n",
>>> + ret);
>>> + goto destroy_changeset;
>>> + }
>>> +
>>> + /* Add device node firmware data */
>>> + pnv_php_add_pdns(php_slot);
>>> + php_slot->fdt = fdt;
>>> + php_slot->dt = dt;
>>> + goto out;
>>> +
>>> +destroy_changeset:
>>> + of_changeset_destroy(&php_slot->ocs);
>>> +free_dt:
>>> + kfree(dt);
>>> + php_slot->dn->child = NULL;
>>> +free_fdt:
>>> + kfree(fdt);
>>> +free_fdt1:
>>> + kfree(fdt1);
>>> +error:
>>> + confirm = PNV_PHP_POWER_CONFIRMED_FAIL;
>>> +out:
>>> + /* Confirm status change */
>>> + php_slot->power_state_confirmed = confirm;
>>> + wake_up_interruptible(&php_slot->queue);
>>> +}
>>> +
>>> +static void pnv_php_work(struct work_struct *data)
>>> +{
>>> + struct pnv_php_slot *php_slot = container_of(data,
>>> + struct pnv_php_slot,
>>> + work);
>>> + uint64_t event = be64_to_cpu(php_slot->msg->params[0]);
>>> +
>>> + if (event == OPAL_PCI_SLOT_POWER_OFF)
>>> + pnv_php_handle_poweroff(php_slot);
>>> + else
>>> + pnv_php_handle_poweron(php_slot);
>>> +
>>> + pnv_php_put_slot(php_slot);
>>> +}
>>> +
>>> +static int pnv_php_handle_msg(struct notifier_block *nb,
>>> + unsigned long type,
>>> + void *message)
>>> +{
>>> + phandle h;
>>> + struct device_node *dn;
>>> + struct pnv_php_slot *php_slot;
>>> + struct opal_msg *msg = message;
>>> +
>>> + if (type != OPAL_MSG_PCI_HOTPLUG) {
>>> + pr_warn("%s: Invalid message %ld received!\n",
>>> + __func__, type);
>>> + return NOTIFY_DONE;
>>> + }
>>> +
>>> + h = (phandle)be64_to_cpu(msg->params[1]);
>>> + dn = of_find_node_by_phandle(h);
>>> + if (!dn) {
>>> + pr_warn("%s: No device node for phandle 0x%x\n",
>>> + __func__, h);
>>> + return NOTIFY_DONE;
>>> + }
>>> +
>>> + php_slot = pnv_php_find_slot(dn);
>>> + if (!php_slot) {
>>> + pr_warn("%s: No slot found for node <%s>\n",
>>> + __func__, of_node_full_name(dn));
>>> + of_node_put(dn);
>>> + return NOTIFY_DONE;
>>> + }
>>> +
>>> + of_node_put(dn);
>>> + php_slot->msg = msg;
>>> + schedule_work(&php_slot->work);
>>> + return NOTIFY_OK;
>>> +}
>>> +
>>> +static int pnv_php_set_power_state(struct hotplug_slot *slot, u8 state)
>>> +{
>>> + struct pnv_php_slot *php_slot = slot->private;
>>> + int ret;
>>> +
>>> + php_slot->power_state_confirmed = PNV_PHP_POWER_CONFIRMED_INVALID;
>>> + ret = pnv_pci_set_power_state(php_slot->id, state);
>>> + if (ret) {
>>> + dev_warn(&php_slot->pdev->dev, "Error %d powering %s slot\n",
>>> + ret, state ? "on" : "off");
>>> + return ret;
>>> + }
>>> +
>>> + /* Continue to PCI probing after finalized device-tree. The
>>> + * device-tree might have been updated completely at this
>>> + * point. Thus we don't have to wait forever.
>>> + */
>>> + if (php_slot->power_state_confirmed == PNV_PHP_POWER_CONFIRMED_SUCCESS)
>>> + return 0;
>>> +
>>> + if (php_slot->power_state_confirmed == PNV_PHP_POWER_CONFIRMED_FAIL)
>>> + return -EBUSY;
>>> +
>>> + /* Wait for firmware to add or remove device sub-tree. When it's done,
>>> + * one signal is received from firmware.
>>> + */
>>> + ret = wait_event_timeout(php_slot->queue,
>>> + php_slot->power_state_confirmed, 10 * HZ);
>>> + if (!ret) {
>>> + dev_warn(&php_slot->pdev->dev, "Error %d waiting for power-%s\n",
>>> + ret, state ? "on" : "off");
>>> + return -EBUSY;
>>> + }
>>> +
>>> + if (php_slot->power_state_confirmed == PNV_PHP_POWER_CONFIRMED_SUCCESS)
>>> + return 0;
>>> +
>>> + dev_warn(&php_slot->pdev->dev, "Error status %d for power-%s\n",
>>> + php_slot->power_state_confirmed, state ? "on" : "off");
>>> + return -EBUSY;
>>> +}
>>> +
>>> +static int pnv_php_get_power_state(struct hotplug_slot *slot, u8 *state)
>>> +{
>>> + struct pnv_php_slot *php_slot = slot->private;
>>> + uint8_t power_state;
>>
>>
>> Uninitialized variable.
>>
>
> When pnv_pci_get_power_state() fails to get the power state, it fails back to
> default one (OPAL_PCI_SLOT_POWER_ON). Otherwise, it is set to the state returned
> from pnv_pci_get_power_state(). The logic is complete.
What does guarantee that if the corresponding OPAL call returned success,
then all data pointers to which you passed to OPAL will point to correct
values? For exampple, the new pnv_pci_poll() updates the state only in some
cases.
> Also, I don't see building warning/error caused by this.
You do not see them now with your current compiler which does not mean you
will never see them.
>>
>>> + 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_state(php_slot->id, &power_state);
>>> + if (ret) {
>>> + *state = OPAL_PCI_SLOT_POWER_ON;
>>> + dev_warn(&php_slot->pdev->dev, "Error %d getting power status\n",
>>> + ret);
>>> + } else {
>>> + *state = power_state;
>>> + slot->info->power_status = power_state;
>>> + }
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int pnv_php_get_adapter_state(struct hotplug_slot *slot, u8 *state)
>>> +{
>>> + struct pnv_php_slot *php_slot = slot->private;
>>> + uint8_t presence;
>>
>> Uninitialized variable.
>>
>
> Same as above.
>
>>> + 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_state(php_slot->id, &presence);
>>> + if (ret >= 0) {
>>> + *state = presence;
>>> + slot->info->adapter_status = presence;
>>> + ret = 0;
>>> + } else {
>>> + *state = OPAL_PCI_SLOT_EMPTY;
>>> + dev_warn(&php_slot->pdev->dev, "Error %d getting presence\n",
>>> + ret);
>>> + }
>>> +
>>> + return ret;
>>> +}
>>> +
>>> +static int pnv_php_set_attention_state(struct hotplug_slot *slot, u8 state)
>>> +{
>>> + /* FIXME: Make it real once firmware supports it */
>>
>> It still does not?
>>
>>
>>> + slot->info->attention_status = state;
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int pnv_php_enable(struct pnv_php_slot *php_slot, bool rescan)
>>> +{
>>> + struct hotplug_slot *slot = &php_slot->slot;
>>> + uint8_t presence, power_status;
>>
>>
>> Uninitialized variables.
>>
>>
>
> I will initialize them to default states in next revision.
Thanks :)
>
>>> + int ret;
>>> +
>>> + /* Check if the slot has been configured */
>>> + if (php_slot->state != PNV_PHP_STATE_REGISTERED)
>>> + return 0;
>>> +
>>> + /* Retrieve slot presence status */
>>> + ret = pnv_php_get_adapter_state(slot, &presence);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + /* Proceed if there have nothing behind the slot */
>>> + if (presence == OPAL_PCI_SLOT_EMPTY)
>>> + goto scan;
>>> +
>>> + /*
>>> + * If the power suply to the slot is off, we can't detect
>>
>> s/suply/supply/
>>
>
> Will fix in next revision.
>
>>> + * adapter presence state. That means we have to turn the
>>> + * slot on before going to probe slot's presence state.
>>> + *
>>> + * 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 (!php_slot->power_state_check) {
>>> + php_slot->power_state_check = true;
>>> +
>>> + ret = pnv_php_get_power_state(slot, &power_status);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + if (power_status != OPAL_PCI_SLOT_POWER_ON)
>>> + return 0;
>>> + }
>>> +
>>> + /* Check the power status. Scan the slot if that's already on */
>>
>>
>> s/that's/it is/
>>
>
> I don't know the difference. Will fix it in next revision anyway.
>
>>
>>> + ret = pnv_php_get_power_state(slot, &power_status);
>>> + if (ret)
>>> + return ret;
>>> +
>>> + if (power_status == OPAL_PCI_SLOT_POWER_ON)
>>> + goto scan;
>>> +
>>> + /* Power is off, turn it on and then scan the slot */
>>> + ret = pnv_php_set_power_state(slot, OPAL_PCI_SLOT_POWER_ON);
>>> + if (ret)
>>> + return ret;
>>> +
>>> +scan:
>>> + if (presence == OPAL_PCI_SLOT_PRESENT) {
>>> + if (rescan) {
>>> + pci_lock_rescan_remove();
>>> + pci_add_pci_devices(php_slot->bus);
>>> + pci_unlock_rescan_remove();
>>> + }
>>> +
>>> + /* Rescan for child hotpluggable slots */
>>> + php_slot->state = PNV_PHP_STATE_POPULATED;
>>> + if (rescan)
>>> + pnv_php_register(php_slot->dn);
>>> + } else {
>>> + php_slot->state = PNV_PHP_STATE_POPULATED;
>>> + }
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static int pnv_php_enable_slot(struct hotplug_slot *slot)
>>> +{
>>> + struct pnv_php_slot *php_slot = container_of(slot,
>>> + struct pnv_php_slot, slot);
>>> +
>>> + return pnv_php_enable(php_slot, true);
>>> +}
>>> +
>>> +static int pnv_php_disable_slot(struct hotplug_slot *slot)
>>> +{
>>> + struct pnv_php_slot *php_slot = slot->private;
>>> + uint8_t power_state;
>>> + int ret;
>>> +
>>> + if (php_slot->state != PNV_PHP_STATE_POPULATED)
>>> + return 0;
>>> +
>>> + /* Remove all devices behind the slot */
>>> + pci_lock_rescan_remove();
>>> + pci_remove_pci_devices(php_slot->bus);
>>> + pci_unlock_rescan_remove();
>>> +
>>> + /* Detach the child hotpluggable slots */
>>> + pnv_php_unregister(php_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 = pnv_php_get_power_state(slot, &power_state);
>>> + if (ret || power_state == OPAL_PCI_SLOT_POWER_ON) {
>>> + ret = pnv_php_set_power_state(slot, OPAL_PCI_SLOT_POWER_OFF);
>>> + if (ret)
>>> + dev_warn(&php_slot->pdev->dev, "Error %d powering off\n",
>>
>>
>> Long line, checkpatch.pl should have warned :)
>>
>
> I didn't see the warning from checkpatch.pl.
Cool, then never mind.
>
>>> + ret);
>>> + }
>>> +
>>> + /* Update slot state */
>>> + php_slot->state = PNV_PHP_STATE_REGISTERED;
>>> + return 0;
>>> +}
>>> +
>>> +static struct hotplug_slot_ops php_slot_ops = {
>>> + .get_power_status = pnv_php_get_power_state,
>>> + .get_adapter_status = pnv_php_get_adapter_state,
>>> + .set_attention_status = pnv_php_set_attention_state,
>>> + .enable_slot = pnv_php_enable_slot,
>>> + .disable_slot = pnv_php_disable_slot,
>>> +};
>>> +
>>> +static void pnv_php_release(struct hotplug_slot *slot)
>>> +{
>>> + struct pnv_php_slot *php_slot = slot->private;
>>> + unsigned long flags;
>>> +
>>> + /* Remove from global or child list */
>>> + spin_lock_irqsave(&pnv_php_lock, flags);
>>> + list_del(&php_slot->link);
>>> + spin_unlock_irqrestore(&pnv_php_lock, flags);
>>> +
>>> + /* Detach from parent */
>>> + pnv_php_put_slot(php_slot);
>>> + pnv_php_put_slot(php_slot->parent);
>>> +}
>>> +
>>> +static int pnv_php_get_slot_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);
>>
>>
>> Is this bit from the same space as 1<<60 as in pnv_eeh_bridge_reset()? If so,
>> it would be great to have all these id bits defined in one place.
>>
>
> Will have a macro (PCI_SLOT_ID) to produce the PCI slot ID in next revision.
>
>>
>>> +
>>> + /* Bus/Slot/Function number */
>>> + prop32 = of_get_property(dn, "reg", NULL);
>>> + if (!prop32)
>>> + return -ENXIO;
>>> + *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 -ENXIO;
>>> + }
>>> +
>>> + *id |= be64_to_cpup(prop64);
>>> + of_node_put(parent);
>>> + return 0;
>>> + }
>>> +
>>> + return -ENODEV;
>>> +}
>>> +
>>> +static struct pnv_php_slot *pnv_php_alloc_slot(struct device_node *dn)
>>> +{
>>> + struct pnv_php_slot *php_slot;
>>> + struct pci_bus *bus;
>>> + const char *label;
>>> + uint64_t id;
>>> +
>>> + label = of_get_property(dn, "ibm,slot-label", NULL);
>>> + if (!label)
>>> + return NULL;
>>> +
>>> + if (pnv_php_get_slot_id(dn, &id))
>>> + return NULL;
>>> +
>>> + bus = pci_find_bus_by_node(dn);
>>> + if (!bus)
>>> + return NULL;
>>> +
>>> + php_slot = kzalloc(sizeof(*php_slot), GFP_KERNEL);
>>> + if (!php_slot)
>>> + return NULL;
>>> +
>>> + php_slot->name = kstrdup(label, GFP_KERNEL);
>>> + if (!php_slot->name) {
>>> + kfree(php_slot);
>>> + return NULL;
>>> + }
>>> +
>>> + if (dn->child && PCI_DN(dn->child))
>>> + php_slot->slot_no = PCI_SLOT(PCI_DN(dn->child)->devfn);
>>> + else
>>> + php_slot->slot_no = -1; /* Placeholder slot */
>>> +
>>> + kref_init(&php_slot->kref);
>>> + php_slot->state = PNV_PHP_STATE_INITIALIZED;
>>> + php_slot->dn = dn;
>>> + php_slot->pdev = bus->self;
>>> + php_slot->bus = bus;
>>> + php_slot->id = id;
>>> + php_slot->power_state_check = false;
>>> + php_slot->power_state_confirmed = PNV_PHP_POWER_CONFIRMED_INVALID;
>>> + php_slot->slot.ops = &php_slot_ops;
>>> + php_slot->slot.info = &php_slot->slot_info;
>>> + php_slot->slot.release = pnv_php_release;
>>> + php_slot->slot.private = php_slot;
>>> +
>>> + INIT_WORK(&php_slot->work, pnv_php_work);
>>> + init_waitqueue_head(&php_slot->queue);
>>> + INIT_LIST_HEAD(&php_slot->children);
>>> + INIT_LIST_HEAD(&php_slot->link);
>>> +
>>> + return php_slot;
>>> +}
>>> +
>>> +static int pnv_php_register_slot(struct pnv_php_slot *php_slot)
>>> +{
>>> + struct pnv_php_slot *parent;
>>> + struct device_node *dn = php_slot->dn;
>>> + unsigned long flags;
>>> + int ret;
>>> +
>>> + /* Check if the slot is registered or not */
>>> + parent = pnv_php_find_slot(php_slot->dn);
>>> + if (parent) {
>>> + pnv_php_put_slot(parent);
>>> + return -EEXIST;
>>> + }
>>> +
>>> + /* Register PCI slot */
>>> + ret = pci_hp_register(&php_slot->slot, php_slot->bus,
>>> + php_slot->slot_no, php_slot->name);
>>> + if (ret) {
>>> + dev_warn(&php_slot->pdev->dev, "Error %d registering slot\n",
>>> + ret);
>>> + return ret;
>>> + }
>>> +
>>> + /* Attach to the parent's child list or global list */
>>> + while ((dn = of_get_parent(dn))) {
>>> + if (!PCI_DN(dn)) {
>>> + of_node_put(dn);
>>> + break;
>>> + }
>>> +
>>> + parent = pnv_php_find_slot(dn);
>>> + if (parent) {
>>> + of_node_put(dn);
>>> + break;
>>> + }
>>> +
>>> + of_node_put(dn);
>>> + }
>>> +
>>> + spin_lock_irqsave(&pnv_php_lock, flags);
>>> + php_slot->parent = parent;
>>> + if (parent)
>>> + list_add_tail(&php_slot->link, &parent->children);
>>> + else
>>> + list_add_tail(&php_slot->link, &pnv_php_slot_list);
>>> + spin_unlock_irqrestore(&pnv_php_lock, flags);
>>> +
>>> + php_slot->state = PNV_PHP_STATE_REGISTERED;
>>> + return 0;
>>> +}
>>> +
>>> +static int pnv_php_register_one(struct device_node *dn)
>>> +{
>>> + struct pnv_php_slot *php_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;
>>> +
>>> + php_slot = pnv_php_alloc_slot(dn);
>>> + if (!php_slot)
>>> + return -ENODEV;
>>> +
>>> + ret = pnv_php_register_slot(php_slot);
>>> + if (ret)
>>> + goto free_slot;
>>> +
>>> + ret = pnv_php_enable(php_slot, false);
>>> + if (ret)
>>> + goto unregister_slot;
>>> +
>>> + return 0;
>>> +
>>> +unregister_slot:
>>> + pnv_php_unregister_one(php_slot->dn);
>>> +free_slot:
>>> + pnv_php_put_slot(php_slot);
>>> + return ret;
>>> +}
>>> +
>>> +static void pnv_php_register(struct device_node *dn)
>>> +{
>>> + struct device_node *child;
>>> +
>>> + /*
>>> + * The parent slots should be registered before their
>>> + * child slots.
>>> + */
>>> + for_each_child_of_node(dn, child) {
>>> + pnv_php_register_one(child);
>>> + pnv_php_register(child);
>>> + }
>>> +}
>>> +
>>> +static void pnv_php_unregister_one(struct device_node *dn)
>>> +{
>>> + struct pnv_php_slot *php_slot;
>>> +
>>> + php_slot = pnv_php_find_slot(dn);
>>> + if (!php_slot)
>>> + return;
>>> +
>>> + pnv_php_put_slot(php_slot);
>>> + pci_hp_deregister(&php_slot->slot);
>>> +}
>>> +
>>> +static void pnv_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) {
>>> + pnv_php_unregister(child);
>>> + pnv_php_unregister_one(child);
>>> + }
>>> +}
>>> +
>>> +static struct notifier_block php_msg_nb = {
>>> + .notifier_call = pnv_php_handle_msg,
>>> + .next = NULL,
>>> + .priority = 0,
>>> +};
>>> +
>>> +static int __init pnv_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")
>>> + pnv_php_register(dn);
>>> + for_each_compatible_node(dn, NULL, "ibm,ioda2-phb")
>>> + pnv_php_register(dn);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static void __exit pnv_php_exit(void)
>>> +{
>>> + struct device_node *dn;
>>> +
>>> + for_each_compatible_node(dn, NULL, "ibm,ioda-phb")
>>> + pnv_php_unregister(dn);
>>> + for_each_compatible_node(dn, NULL, "ibm,ioda2-phb")
>>> + pnv_php_unregister(dn);
>>> +
>>> + pnv_pci_hotplug_notifier_unregister(&php_msg_nb);
>>> +}
>>> +
>>> +module_init(pnv_php_init);
>>> +module_exit(pnv_php_exit);
>>> +
>>> +MODULE_VERSION(DRIVER_VERSION);
>>> +MODULE_LICENSE("GPL v2");
>>> +MODULE_AUTHOR(DRIVER_AUTHOR);
>>> +MODULE_DESCRIPTION(DRIVER_DESC);
>>>
>>
>>
>> --
>> Alexey
>>
>
--
Alexey
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