On Tue, Jul 9, 2013 at 1:55 AM, Yijing Wang <wangyijing@xxxxxxxxxx> 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.
>
> Signed-off-by: Yijing Wang <wangyijing@xxxxxxxxxx>
> 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)
How about:
u64 pci_device_serial_number(struct pci_dev *dev)
"get" suggests reference counting, which isn't happening here. And
why pass a pointer to a return value when we can just as easily return
it directly?
> +{
> + 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);
dev->sn = pci_serial_number(dev);
Obvious, no comment or wrapper function needed.
> +
> /* 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);
> --
> 1.7.1
>
>
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