On 2013/7/9 16:09, Gu Zheng wrote:
> On 07/09/2013 03:55 PM, Yijing Wang wrote:
>
>> Introduce PCIe Ext Capability Device Serial Number support,
>> so we can use the unique device serial number to identify
>> the physical device. During system suspend, if the PCIe
>> device was removed and inserted a new same device, after
>> system resume there is no good way to identify it, maybe
>> Device Serial Number is a good choice if device support.
>
> Nice idea!
>
> Regards,
> Gu
>
>>
>> Signed-off-by: Yijing Wang <wangyijing@xxxxxxxxxx>
>
>
> Reviewed-by: Gu Zheng <guz.fnst@xxxxxxxxxxxxxx>
Thanks very much!
Yijing.
>
>> Cc: "Rafael J. Wysocki" <rjw@xxxxxxx>
>> Cc: Oliver Neukum <oneukum@xxxxxxx>
>> Cc: Paul Bolle <pebolle@xxxxxxxxxx>
>> Cc: Gu Zheng <guz.fnst@xxxxxxxxxxxxxx>
>> Cc: linux-pci@xxxxxxxxxxxxxxx
>> ---
>> drivers/pci/pci.c | 33 +++++++++++++++++++++++++++++++++
>> drivers/pci/pci.h | 1 +
>> drivers/pci/probe.c | 3 +++
>> include/linux/pci.h | 4 ++++
>> 4 files changed, 41 insertions(+), 0 deletions(-)
>>
>> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
>> index e37fea6..d08df2b 100644
>> --- a/drivers/pci/pci.c
>> +++ b/drivers/pci/pci.c
>> @@ -2048,6 +2048,39 @@ void pci_free_cap_save_buffers(struct pci_dev *dev)
>> }
>>
>> /**
>> + * pci_get_dsn - get device serial number
>> + * @dev: the PCI device
>> + * @sn: saved device serial number
>> + */
>> +void pci_get_dsn(struct pci_dev *dev, u64 *sn)
>> +{
>> + int pos;
>> + u32 lo, hi;
>> +
>> + if (!pci_is_pcie(dev))
>> + goto out;
>> +
>> + pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DSN);
>> + if (!pos)
>> + goto out;
>> +
>> + pci_read_config_dword(dev, pos + 4, &lo);
>> + pci_read_config_dword(dev, pos + 8, &hi);
>> + *sn = ((u64)hi << 32) | lo;
>> + return;
>> +
>> +out:
>> + *sn = 0;
>> + return;
>> +}
>> +EXPORT_SYMBOL(pci_get_dsn);
>> +
>> +void pci_dsn_init(struct pci_dev *dev)
>> +{
>> + return pci_get_dsn(dev, &dev->sn);
>> +}
>> +
>> +/**
>> * pci_configure_ari - enable or disable ARI forwarding
>> * @dev: the PCI device
>> *
>> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
>> index 68678ed..f626006 100644
>> --- a/drivers/pci/pci.h
>> +++ b/drivers/pci/pci.h
>> @@ -202,6 +202,7 @@ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type,
>> struct resource *res, unsigned int reg);
>> int pci_resource_bar(struct pci_dev *dev, int resno, enum pci_bar_type *type);
>> void pci_configure_ari(struct pci_dev *dev);
>> +void pci_dsn_init(struct pci_dev *dev);
>>
>> /**
>> * pci_ari_enabled - query ARI forwarding status
>> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
>> index 46ada5c..d4c6e7e 100644
>> --- a/drivers/pci/probe.c
>> +++ b/drivers/pci/probe.c
>> @@ -1322,6 +1322,9 @@ static void pci_init_capabilities(struct pci_dev *dev)
>> /* Power Management */
>> pci_pm_init(dev);
>>
>> + /* Device Serial Number */
>> + pci_dsn_init(dev);
>> +
>> /* Vital Product Data */
>> pci_vpd_pci22_init(dev);
>>
>> diff --git a/include/linux/pci.h b/include/linux/pci.h
>> index 0fd1f15..59cd205 100644
>> --- a/include/linux/pci.h
>> +++ b/include/linux/pci.h
>> @@ -342,6 +342,7 @@ struct pci_dev {
>> struct list_head msi_list;
>> struct kset *msi_kset;
>> #endif
>> + u64 sn; /* device serieal number, 0 if not support */
>> struct pci_vpd *vpd;
>> #ifdef CONFIG_PCI_ATS
>> union {
>> @@ -995,6 +996,9 @@ ssize_t pci_read_vpd(struct pci_dev *dev, loff_t pos, size_t count, void *buf);
>> ssize_t pci_write_vpd(struct pci_dev *dev, loff_t pos, size_t count, const void *buf);
>> int pci_vpd_truncate(struct pci_dev *dev, size_t size);
>>
>> +/* Device Serial Number */
>> +void pci_get_dsn(struct pci_dev *dev, u64 *sn);
>> +
>> /* Helper functions for low-level code (drivers/pci/setup-[bus,res].c) */
>> resource_size_t pcibios_retrieve_fw_addr(struct pci_dev *dev, int idx);
>> void pci_bus_assign_resources(const struct pci_bus *bus);
>
>
>
> .
>
--
Thanks!
Yijing
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