Re: [PATCH 2/9] platform/x86/intel/sdsi: Hide attributes if hardware doesn't support

Hans de Goede
2022-11-17T13:19:53Z

Hi,

On 11/1/22 20:10, David E. Box wrote:
> Provisioning capabilities are enabled by a bit set by BIOS. Read this bit
> and hide the provisioning attributes if the On Demand feature is not
> enabled.
>
> Also, remove the sdsi_enabled boolean from private and instead add a
> features register since this will be used for future features.
>
> Signed-off-by: David E. Box <david.e.box@linux.intel.com>

Thanks, patch looks good to me:

Reviewed-by: Hans de Goede <hdegoede@redhat.com>

Regards,

Hans

> ---
> drivers/platform/x86/intel/sdsi.c | 33 ++++++++++++++++++++-----------
> 1 file changed, 22 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/platform/x86/intel/sdsi.c b/drivers/platform/x86/intel/sdsi.c
> index 32793919473d..bca05b4dd983 100644
> --- a/drivers/platform/x86/intel/sdsi.c
> +++ b/drivers/platform/x86/intel/sdsi.c
> @@ -41,7 +41,8 @@
> #define SDSI_SIZE_READ_MSG (SDSI_SIZE_MAILBOX * 4)
>
> #define SDSI_ENABLED_FEATURES_OFFSET 16
> -#define SDSI_ENABLED BIT(3)
> +#define SDSI_FEATURE_SDSI BIT(3)
> +
> #define SDSI_SOCKET_ID_OFFSET 64
> #define SDSI_SOCKET_ID GENMASK(3, 0)
>
> @@ -100,7 +101,7 @@ struct sdsi_priv {
> void __iomem *mbox_addr;
> void __iomem *regs_addr;
> u32 guid;
> - bool sdsi_enabled;
> + u32 features;
> };
>
> /* SDSi mailbox operations must be performed using 64bit mov instructions */
> @@ -332,9 +333,6 @@ static ssize_t sdsi_provision(struct sdsi_priv *priv, char *buf, size_t count,
> struct sdsi_mbox_info info;
> int ret;
>
> - if (!priv->sdsi_enabled)
> - return -EPERM;
> -
> if (count > (SDSI_SIZE_WRITE_MSG - SDSI_SIZE_CMD))
> return -EOVERFLOW;
>
> @@ -405,9 +403,6 @@ static long state_certificate_read(struct file *filp, struct kobject *kobj,
> size_t size;
> int ret;
>
> - if (!priv->sdsi_enabled)
> - return -EPERM;
> -
> if (off)
> return 0;
>
> @@ -464,6 +459,23 @@ static struct bin_attribute *sdsi_bin_attrs[] = {
> NULL
> };
>
> +static umode_t
> +sdsi_battr_is_visible(struct kobject *kobj, struct bin_attribute *attr, int n)
> +{
> + struct device *dev = kobj_to_dev(kobj);
> + struct sdsi_priv *priv = dev_get_drvdata(dev);
> +
> + /* Registers file is always readable if the device is present */
> + if (attr == &bin_attr_registers)
> + return attr->attr.mode;
> +
> + /* All other attributes not visible if BIOS has not enabled On Demand */
> + if (!(priv->features & SDSI_FEATURE_SDSI))
> + return 0;
> +
> + return attr->attr.mode;
> +}
> +
> static ssize_t guid_show(struct device *dev, struct device_attribute *attr, char *buf)
> {
> struct sdsi_priv *priv = dev_get_drvdata(dev);
> @@ -480,6 +492,7 @@ static struct attribute *sdsi_attrs[] = {
> static const struct attribute_group sdsi_group = {
> .attrs = sdsi_attrs,
> .bin_attrs = sdsi_bin_attrs,
> + .is_bin_visible = sdsi_battr_is_visible,
> };
> __ATTRIBUTE_GROUPS(sdsi);
>
> @@ -490,7 +503,6 @@ static int sdsi_map_mbox_registers(struct sdsi_priv *priv, struct pci_dev *paren
> u32 size = FIELD_GET(DT_SIZE, disc_table->access_info);
> u32 tbir = FIELD_GET(DT_TBIR, disc_table->offset);
> u32 offset = DT_OFFSET(disc_table->offset);
> - u32 features_offset;
> struct resource res = {};
>
> /* Starting location of SDSi MMIO region based on access type */
> @@ -528,8 +540,7 @@ static int sdsi_map_mbox_registers(struct sdsi_priv *priv, struct pci_dev *paren
> priv->mbox_addr = priv->control_addr + SDSI_SIZE_CONTROL;
> priv->regs_addr = priv->mbox_addr + SDSI_SIZE_MAILBOX;
>
> - features_offset = readq(priv->regs_addr + SDSI_ENABLED_FEATURES_OFFSET);
> - priv->sdsi_enabled = !!(features_offset & SDSI_ENABLED);
> + priv->features = readq(priv->regs_addr + SDSI_ENABLED_FEATURES_OFFSET);
>
> return 0;
> }