On 2/27/24 4:00 PM, David E. Box wrote:
> The meter_certificate file provides access to metering information that may
> be attested but is only updated every 8 hours. Add new attribute,
> meter_current, to allow reading an untested snapshot of the current values.
>
> Signed-off-by: David E. Box <david.e.box@xxxxxxxxxxxxxxx>
> ---
Looks good to me.
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>
>
> V2 - make control_flags a parameter to be eventually passed to
> sdsi_mbox_cmd_read(). This removes the need for a lock which had been
> added to protect control_flags when it was a member of the private
> struct.
>
> drivers/platform/x86/intel/sdsi.c | 30 ++++++++++++++++++++++++------
> 1 file changed, 24 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/platform/x86/intel/sdsi.c b/drivers/platform/x86/intel/sdsi.c
> index bb3eaf5eb382..277e4f4b20ac 100644
> --- a/drivers/platform/x86/intel/sdsi.c
> +++ b/drivers/platform/x86/intel/sdsi.c
> @@ -68,6 +68,7 @@
> #define CTRL_COMPLETE BIT(6)
> #define CTRL_READY BIT(7)
> #define CTRL_INBAND_LOCK BIT(32)
> +#define CTRL_METER_ENABLE_DRAM BIT(33)
> #define CTRL_STATUS GENMASK(15, 8)
> #define CTRL_PACKET_SIZE GENMASK(31, 16)
> #define CTRL_MSG_SIZE GENMASK(63, 48)
> @@ -95,6 +96,7 @@ enum sdsi_command {
> struct sdsi_mbox_info {
> u64 *payload;
> void *buffer;
> + u64 control_flags;
> int size;
> };
>
> @@ -250,7 +252,8 @@ static int sdsi_mbox_cmd_read(struct sdsi_priv *priv, struct sdsi_mbox_info *inf
> control = FIELD_PREP(CTRL_EOM, 1) |
> FIELD_PREP(CTRL_SOM, 1) |
> FIELD_PREP(CTRL_RUN_BUSY, 1) |
> - FIELD_PREP(CTRL_PACKET_SIZE, info->size);
> + FIELD_PREP(CTRL_PACKET_SIZE, info->size) |
> + info->control_flags;
> writeq(control, priv->control_addr);
>
> return sdsi_mbox_poll(priv, info, data_size);
> @@ -424,8 +427,8 @@ static ssize_t provision_cap_write(struct file *filp, struct kobject *kobj,
> static BIN_ATTR_WO(provision_cap, SDSI_SIZE_WRITE_MSG);
>
> static ssize_t
> -certificate_read(u64 command, struct sdsi_priv *priv, char *buf, loff_t off,
> - size_t count)
> +certificate_read(u64 command, u64 control_flags, struct sdsi_priv *priv,
> + char *buf, loff_t off, size_t count)
> {
> struct sdsi_mbox_info info = {};
> size_t size;
> @@ -441,6 +444,7 @@ certificate_read(u64 command, struct sdsi_priv *priv, char *buf, loff_t off,
>
> info.payload = &command;
> info.size = sizeof(command);
> + info.control_flags = control_flags;
>
> ret = mutex_lock_interruptible(&priv->mb_lock);
> if (ret)
> @@ -472,7 +476,7 @@ state_certificate_read(struct file *filp, struct kobject *kobj,
> struct device *dev = kobj_to_dev(kobj);
> struct sdsi_priv *priv = dev_get_drvdata(dev);
>
> - return certificate_read(SDSI_CMD_READ_STATE, priv, buf, off, count);
> + return certificate_read(SDSI_CMD_READ_STATE, 0, priv, buf, off, count);
> }
> static BIN_ATTR_ADMIN_RO(state_certificate, SDSI_SIZE_READ_MSG);
>
> @@ -484,10 +488,23 @@ meter_certificate_read(struct file *filp, struct kobject *kobj,
> struct device *dev = kobj_to_dev(kobj);
> struct sdsi_priv *priv = dev_get_drvdata(dev);
>
> - return certificate_read(SDSI_CMD_READ_METER, priv, buf, off, count);
> + return certificate_read(SDSI_CMD_READ_METER, 0, priv, buf, off, count);
> }
> static BIN_ATTR_ADMIN_RO(meter_certificate, SDSI_SIZE_READ_MSG);
>
> +static ssize_t
> +meter_current_read(struct file *filp, struct kobject *kobj,
> + struct bin_attribute *attr, char *buf, loff_t off,
> + size_t count)
> +{
> + struct device *dev = kobj_to_dev(kobj);
> + struct sdsi_priv *priv = dev_get_drvdata(dev);
> +
> + return certificate_read(SDSI_CMD_READ_METER, CTRL_METER_ENABLE_DRAM,
> + priv, buf, off, count);
> +}
> +static BIN_ATTR_ADMIN_RO(meter_current, SDSI_SIZE_READ_MSG);
> +
> static ssize_t registers_read(struct file *filp, struct kobject *kobj,
> struct bin_attribute *attr, char *buf, loff_t off,
> size_t count)
> @@ -518,6 +535,7 @@ static struct bin_attribute *sdsi_bin_attrs[] = {
> &bin_attr_registers,
> &bin_attr_state_certificate,
> &bin_attr_meter_certificate,
> + &bin_attr_meter_current,
> &bin_attr_provision_akc,
> &bin_attr_provision_cap,
> NULL
> @@ -537,7 +555,7 @@ sdsi_battr_is_visible(struct kobject *kobj, struct bin_attribute *attr, int n)
> if (!(priv->features & SDSI_FEATURE_SDSI))
> return 0;
>
> - if (attr == &bin_attr_meter_certificate)
> + if (attr == &bin_attr_meter_certificate || attr == &bin_attr_meter_current)
> return (priv->features & SDSI_FEATURE_METERING) ?
> attr->attr.mode : 0;
>
--
Sathyanarayanan Kuppuswamy
Linux Kernel Developer
