[PATCH 07/10] ocxl: Save the device serial number in ocxl_fn

[Frederic Barrat]

Le 25/10/2019 à 06:47, Alastair D'Silva a écrit :
> From: Alastair D'Silva <alastair at d-silva.org>
> 
> This patch retrieves the serial number of the card and makes it available
> to consumers of the ocxl driver via the ocxl_fn struct.
> 
> Signed-off-by: Alastair D'Silva <alastair at d-silva.org>
> ---


Acked-by: Frederic Barrat <fbarrat at linux.ibm.com>



>   drivers/misc/ocxl/config.c | 46 ++++++++++++++++++++++++++++++++++++++
>   include/misc/ocxl.h        |  1 +
>   2 files changed, 47 insertions(+)
> 
> diff --git a/drivers/misc/ocxl/config.c b/drivers/misc/ocxl/config.c
> index fb0c3b6f8312..a9203c309365 100644
> --- a/drivers/misc/ocxl/config.c
> +++ b/drivers/misc/ocxl/config.c
> @@ -71,6 +71,51 @@ static int find_dvsec_afu_ctrl(struct pci_dev *dev, u8 afu_idx)
>   	return 0;
>   }
>   
> +/**
> + * Find a related PCI device (function 0)
> + * @device: PCI device to match
> + *
> + * Returns a pointer to the related device, or null if not found
> + */
> +static struct pci_dev *get_function_0(struct pci_dev *dev)
> +{
> +	unsigned int devfn = PCI_DEVFN(PCI_SLOT(dev->devfn), 0); // Look for function 0
> +
> +	return pci_get_domain_bus_and_slot(pci_domain_nr(dev->bus),
> +					dev->bus->number, devfn);
> +}
> +
> +static void read_serial(struct pci_dev *dev, struct ocxl_fn_config *fn)
> +{
> +	u32 low, high;
> +	int pos;
> +
> +	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DSN);
> +	if (pos) {
> +		pci_read_config_dword(dev, pos + 0x04, &low);
> +		pci_read_config_dword(dev, pos + 0x08, &high);
> +
> +		fn->serial = low | ((u64)high) << 32;
> +
> +		return;
> +	}
> +
> +	if (PCI_FUNC(dev->devfn) != 0) {
> +		struct pci_dev *related = get_function_0(dev);
> +
> +		if (!related) {
> +			fn->serial = 0;
> +			return;
> +		}
> +
> +		read_serial(related, fn);
> +		pci_dev_put(related);
> +		return;
> +	}
> +
> +	fn->serial = 0;
> +}
> +
>   static void read_pasid(struct pci_dev *dev, struct ocxl_fn_config *fn)
>   {
>   	u16 val;
> @@ -208,6 +253,7 @@ int ocxl_config_read_function(struct pci_dev *dev, struct ocxl_fn_config *fn)
>   	int rc;
>   
>   	read_pasid(dev, fn);
> +	read_serial(dev, fn);
>   
>   	rc = read_dvsec_tl(dev, fn);
>   	if (rc) {
> diff --git a/include/misc/ocxl.h b/include/misc/ocxl.h
> index 6f7c02f0d5e3..9843051c3c5b 100644
> --- a/include/misc/ocxl.h
> +++ b/include/misc/ocxl.h
> @@ -46,6 +46,7 @@ struct ocxl_fn_config {
>   	int dvsec_afu_info_pos; /* offset of the AFU information DVSEC */
>   	s8 max_pasid_log;
>   	s8 max_afu_index;
> +	u64 serial;
>   };
>   
>   enum ocxl_endian {
>