| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Tue, 11 Nov 2014 12:12:27 +0530
From: Kishon Vijay Abraham I <kishon@...com>
To: Vivek Gautam <gautam.vivek@...sung.com>,
Heikki Krogerus <heikki.krogerus@...ux.intel.com>
CC: "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
Linux USB Mailing List <linux-usb@...r.kernel.org>,
<andrew.kim@...el.com>
Subject: Re: [PATCHv4 2/6] phy: improved lookup method
Hi,
On Friday 31 October 2014 06:03 PM, Vivek Gautam wrote:
> Hi Heikki,
>
>
> On Fri, Oct 17, 2014 at 8:09 PM, Heikki Krogerus
> <heikki.krogerus@...ux.intel.com> wrote:
>> Removes the need for the phys to be aware of their users
>> even when not using DT. The method is copied from clkdev.c.
>>
>> Signed-off-by: Heikki Krogerus <heikki.krogerus@...ux.intel.com>
>> Tested-by: Vivek Gautam <gautam.vivek@...sung.com>
>> ---
>> Documentation/phy.txt | 66 ++++++++---------------
>> drivers/phy/phy-core.c | 135 +++++++++++++++++++++++++++++++++++++++++++++++-
>> include/linux/phy/phy.h | 27 ++++++++++
>> 3 files changed, 183 insertions(+), 45 deletions(-)
>>
>> diff --git a/Documentation/phy.txt b/Documentation/phy.txt
>> index c6594af..8add515 100644
>> --- a/Documentation/phy.txt
>> +++ b/Documentation/phy.txt
>> @@ -54,18 +54,14 @@ The PHY driver should create the PHY in order for other peripheral controllers
>> to make use of it. The PHY framework provides 2 APIs to create the PHY.
>>
>> struct phy *phy_create(struct device *dev, struct device_node *node,
>> - const struct phy_ops *ops,
>> - struct phy_init_data *init_data);
>> + const struct phy_ops *ops);
>> struct phy *devm_phy_create(struct device *dev, struct device_node *node,
>> - const struct phy_ops *ops,
>> - struct phy_init_data *init_data);
>> + const struct phy_ops *ops);
>>
>> The PHY drivers can use one of the above 2 APIs to create the PHY by passing
>> -the device pointer, phy ops and init_data.
>> +the device pointer and phy ops.
>> phy_ops is a set of function pointers for performing PHY operations such as
>> -init, exit, power_on and power_off. *init_data* is mandatory to get a reference
>> -to the PHY in the case of non-dt boot. See section *Board File Initialization*
>> -on how init_data should be used.
>> +init, exit, power_on and power_off.
>>
>> Inorder to dereference the private data (in phy_ops), the phy provider driver
>> can use phy_set_drvdata() after creating the PHY and use phy_get_drvdata() in
>> @@ -137,42 +133,24 @@ There are exported APIs like phy_pm_runtime_get, phy_pm_runtime_get_sync,
>> phy_pm_runtime_put, phy_pm_runtime_put_sync, phy_pm_runtime_allow and
>> phy_pm_runtime_forbid for performing PM operations.
>>
>> -8. Board File Initialization
>> -
>> -Certain board file initialization is necessary in order to get a reference
>> -to the PHY in the case of non-dt boot.
>> -Say we have a single device that implements 3 PHYs that of USB, SATA and PCIe,
>> -then in the board file the following initialization should be done.
>> -
>> -struct phy_consumer consumers[] = {
>> - PHY_CONSUMER("dwc3.0", "usb"),
>> - PHY_CONSUMER("pcie.0", "pcie"),
>> - PHY_CONSUMER("sata.0", "sata"),
>> -};
>> -PHY_CONSUMER takes 2 parameters, first is the device name of the controller
>> -(PHY consumer) and second is the port name.
>> -
>> -struct phy_init_data init_data = {
>> - .consumers = consumers,
>> - .num_consumers = ARRAY_SIZE(consumers),
>> -};
>> -
>> -static const struct platform_device pipe3_phy_dev = {
>> - .name = "pipe3-phy",
>> - .id = -1,
>> - .dev = {
>> - .platform_data = {
>> - .init_data = &init_data,
>> - },
>> - },
>> -};
>> -
>> -then, while doing phy_create, the PHY driver should pass this init_data
>> - phy_create(dev, ops, pdata->init_data);
>> -
>> -and the controller driver (phy consumer) should pass the port name along with
>> -the device to get a reference to the PHY
>> - phy_get(dev, "pcie");
>> +8. PHY Mappings
>> +
>> +In order to get reference to a PHY without help from DeviceTree, the framework
>> +offers lookups which can be compared to clkdev that allow clk structures to be
>> +bound to devices. A lookup can be made statically by directly registering
>> +phy_lookup structure which contains the name of the PHY device, the name of the
>> +device which the PHY will be bind to and Connection ID string. Alternatively a
>> +lookup can be made during runtime when a handle to the struct phy already
>> +exists.
>> +
>> +The framework offers the following APIs for registering and unregistering the
>> +lookups.
>> +
>> +void phy_register_lookup(struct phy_lookup *pl);
>> +int phy_create_lookup(struct phy *phy, const char *con_id, const char *dev_id);
>> +
>> +void phy_unregister_lookup(struct phy_lookup *pl);
>> +void phy_remove_lookup(struct phy *phy, const char *con_id, const char *dev_id);
>>
>> 9. DeviceTree Binding
>>
>> diff --git a/drivers/phy/phy-core.c b/drivers/phy/phy-core.c
>> index ff5eec5..c8d0f66 100644
>> --- a/drivers/phy/phy-core.c
>> +++ b/drivers/phy/phy-core.c
>> @@ -26,6 +26,7 @@
>> static struct class *phy_class;
>> static DEFINE_MUTEX(phy_provider_mutex);
>> static LIST_HEAD(phy_provider_list);
>> +static LIST_HEAD(phys);
>> static DEFINE_IDA(phy_ida);
>>
>> static void devm_phy_release(struct device *dev, void *res)
>> @@ -84,6 +85,138 @@ static struct phy *phy_lookup(struct device *device, const char *port)
>> return ERR_PTR(-ENODEV);
>> }
>>
>> +/**
>> + * phy_register_lookup() - register PHY/device association
>> + * @pl: association to register
>> + */
>> +void phy_register_lookup(struct phy_lookup *pl)
>> +{
>> + mutex_lock(&phy_provider_mutex);
>> + list_add_tail(&pl->node, &phys);
>> + mutex_unlock(&phy_provider_mutex);
>> +}
>> +
>> +/**
>> + * phy_unregister_lookup() - remove PHY/device association
>> + * @pl: association to be removed
>> + */
>> +void phy_unregister_lookup(struct phy_lookup *pl)
>> +{
>> + mutex_lock(&phy_provider_mutex);
>> + list_del(&pl->node);
>> + mutex_unlock(&phy_provider_mutex);
>> +}
>> +
>> +/**
>> + * phy_create_lookup() - allocate and register PHY/device association
>> + * @phy: the phy of the association
>> + * @con_id: connection ID string on device
>> + * @dev_id: the device of the association
>> + *
>> + * Creates and registers phy_lookup entry.
>> + */
>> +int phy_create_lookup(struct phy *phy, const char *con_id, const char *dev_id)
>> +{
>> + struct phy_lookup *pl;
>> +
>> + if (!phy || (!dev_id && !con_id))
>> + return -EINVAL;
>> +
>> + pl = kzalloc(sizeof(*pl), GFP_KERNEL);
>> + if (!pl)
>> + return -ENOMEM;
>> +
>> + pl->phy_name = dev_name(phy->dev.parent);
>> + pl->dev_id = dev_id;
>> + pl->con_id = con_id;
>> +
>> + phy_register_lookup(pl);
>> +
>> + return 0;
>> +}
>> +EXPORT_SYMBOL_GPL(phy_create_lookup);
>> +
>> +/**
>> + * phy_remove_lookup() - find and remove PHY/device association
>> + * @phy: the phy of the association
>> + * @con_id: connection ID string on device
>> + * @dev_id: the device of the association
>> + *
>> + * Finds and unregisters phy_lookup entry that was created with
>> + * phy_create_lookup().
>> + */
>> +void phy_remove_lookup(struct phy *phy, const char *con_id, const char *dev_id)
>> +{
>> + struct phy_lookup *pl;
>> +
>> + if (!phy || (!dev_id && !con_id))
>> + return;
>> +
>> + list_for_each_entry(pl, &phys, node)
>> + if (!strcmp(pl->phy_name, dev_name(phy->dev.parent)) &&
>> + !strcmp(pl->dev_id, dev_id) &&
>> + !strcmp(pl->con_id, con_id)) {
>> + phy_unregister_lookup(pl);
>> + kfree(pl);
>> + return;
>> + }
>> +}
>> +EXPORT_SYMBOL_GPL(phy_remove_lookup);
>> +
>> +static struct phy *phy_find(struct device *dev, const char *con_id)
>> +{
>> + const char *dev_id = dev ? dev_name(dev) : NULL;
>> + int match, best_found = 0, best_possible = 0;
>> + struct phy *phy = ERR_PTR(-ENODEV);
>> + struct phy_lookup *p, *pl = NULL;
>> +
>> + if (dev_id)
>> + best_possible += 2;
>> + if (con_id)
>> + best_possible += 1;
>> +
>> + list_for_each_entry(p, &phys, node) {
>> + match = 0;
>> + if (p->dev_id) {
>> + if (!dev_id || strcmp(p->dev_id, dev_id))
>> + continue;
>> + match += 2;
>> + }
>> + if (p->con_id) {
>> + if (!con_id || strcmp(p->con_id, con_id))
>> + continue;
>> + match += 1;
>> + }
>> +
>> + if (match > best_found) {
>> + pl = p;
>> + if (match != best_possible)
>> + best_found = match;
>> + else
>> + break;
>> + }
>> + }
>> +
>> + if (pl) {
>> + struct class_dev_iter iter;
>> + struct device *phy_dev;
>> +
>> + class_dev_iter_init(&iter, phy_class, NULL, NULL);
>> + while ((phy_dev = class_dev_iter_next(&iter))) {
>
> We have the case with phy-exynos5-usbdrd driver, which registers two
> phys usb2-phy and usb3-phy
> both being used by xhci (after dwc3 creates a lookup table).
>
> The phy_dev is coming same for both the PHYs, and that's the reason
> when i try to get
> "usb2-phy" and "usb3-phy" i end up getting only usb2-phy.
> This is happening with V4 of this patch; V3 seems fine. The only
> differnece i see is
> we are creating the phy_lookup_table using phy_dev->parent.
>
> Is there something that i am missing ?
looks like a genuine problem.
>
>> + if (!strcmp(dev_name(phy_dev->parent), pl->phy_name)) {
here there are two phys which has the same parent and the first one that
matches will be returned. Hence you always get "usb2-phy".
IIUC just with device names of parent, we won't be able to get the PHY. We need
another 'variable' to differentiate it's children. Or have *phy* pointer
directly in the lookup table like how clk driver does?
Thanks
Kishon
>> + phy = to_phy(phy_dev);
>> + break;
>> + }
>> + }
>> + class_dev_iter_exit(&iter);
>> + }
>> +
>> + /* fall-back to the old lookup method for now */
>> + if (IS_ERR(phy))
>> + phy = phy_lookup(dev, con_id);
>> + return phy;
>> +}
>> +
>> static struct phy_provider *of_phy_provider_lookup(struct device_node *node)
>> {
>> struct phy_provider *phy_provider;
>> @@ -463,7 +596,7 @@ struct phy *phy_get(struct device *dev, const char *string)
>> string);
>> phy = _of_phy_get(dev->of_node, index);
>> } else {
>> - phy = phy_lookup(dev, string);
>> + phy = phy_find(dev, string);
>> }
>> if (IS_ERR(phy))
>> return phy;
>> diff --git a/include/linux/phy/phy.h b/include/linux/phy/phy.h
>> index 9fda683..2696b95 100644
>> --- a/include/linux/phy/phy.h
>> +++ b/include/linux/phy/phy.h
>> @@ -110,6 +110,20 @@ struct phy_init_data {
>> .port = _port, \
>> }
>>
>> +struct phy_lookup {
>> + struct list_head node;
>> + const char *phy_name;
>> + const char *dev_id;
>> + const char *con_id;
>> +};
>> +
>> +#define PHY_LOOKUP(a, b, c) \
>> + { \
>> + .phy_name = a, \
>> + .dev_id = b, \
>> + .con_id = c, \
>> + }
>> +
>> #define to_phy(a) (container_of((a), struct phy, dev))
>>
>> #define of_phy_provider_register(dev, xlate) \
>> @@ -174,6 +188,10 @@ struct phy_provider *__devm_of_phy_provider_register(struct device *dev,
>> void of_phy_provider_unregister(struct phy_provider *phy_provider);
>> void devm_of_phy_provider_unregister(struct device *dev,
>> struct phy_provider *phy_provider);
>> +void phy_register_lookup(struct phy_lookup *pl);
>> +void phy_unregister_lookup(struct phy_lookup *pl);
>> +int phy_create_lookup(struct phy *phy, const char *con_id, const char *dev_id);
>> +void phy_remove_lookup(struct phy *phy, const char *con_id, const char *dev_id);
>> #else
>> static inline int phy_pm_runtime_get(struct phy *phy)
>> {
>> @@ -345,6 +363,15 @@ static inline void devm_of_phy_provider_unregister(struct device *dev,
>> struct phy_provider *phy_provider)
>> {
>> }
>> +static inline void phy_register_lookup(struct phy_lookup *pl) { }
>> +static inline void phy_unregister_lookup(struct phy_lookup *pl) { }
>> +static inline int
>> +phy_create_lookup(struct phy *phy, const char *con_id, const char *dev_id)
>> +{
>> + return 0;
>> +}
>> +static inline void phy_remove_lookup(struct phy *phy, const char *con_id,
>> + const char *dev_id) { }
>> #endif
>>
>> #endif /* __DRIVERS_PHY_H */
>> --
>> 2.1.1
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-usb" in
>> the body of a message to majordomo@...r.kernel.org
>> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
>
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists