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

Message ID 20221101191023.4150315-3-david.e.box@linux.intel.com
State New
Headers
Series Extend Intel On Demand (SDSi) support |

Commit Message

David E. Box Nov. 1, 2022, 7:10 p.m. UTC
  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>
---
 drivers/platform/x86/intel/sdsi.c | 33 ++++++++++++++++++++-----------
 1 file changed, 22 insertions(+), 11 deletions(-)
  

Comments

Hans de Goede Nov. 17, 2022, 1:18 p.m. UTC | #1
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;
>  }
  

Patch

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;
 }