[PATCH] drm/xe/hwmon: Update xe hwmon with couple of fixes

[Gupta, Anshuman]

> -----Original Message-----
> From: Poosa, Karthik <karthik.poosa at intel.com>
> Sent: Thursday, March 28, 2024 7:32 PM
> To: intel-xe at lists.freedesktop.org
> Cc: Gupta, Anshuman <anshuman.gupta at intel.com>; Nilawar, Badal
> <badal.nilawar at intel.com>; Vivi, Rodrigo <rodrigo.vivi at intel.com>; Poosa,
> Karthik <karthik.poosa at intel.com>
> Subject: [PATCH] drm/xe/hwmon: Update xe hwmon with couple of fixes
> 
> Fix potential overflows with upcasting.
> Initialize variables which were being used uninitialized.
Few initialization is not needed as reg_val is initialized be call by reference.
> 
> Fixes: 4446fcf220ce ("drm/xe/hwmon: Expose power1_max_interval")
> Signed-off-by: Karthik Poosa <karthik.poosa at intel.com>
Few reg_value initialization  is not needed as those were initialized by xe_hwmon_process_reg()
but for symmetry 
Reviewed-by: Anshuman Gupta <anshuman.gupta at intel.com>
Thanks,
Anshuman Gupta.
> ---
>  drivers/gpu/drm/xe/xe_hwmon.c | 18 +++++++++---------
>  1 file changed, 9 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_hwmon.c
> b/drivers/gpu/drm/xe/xe_hwmon.c index a256af8c2012..6ed9d5c4f6b1 100644
> --- a/drivers/gpu/drm/xe/xe_hwmon.c
> +++ b/drivers/gpu/drm/xe/xe_hwmon.c
> @@ -153,7 +153,7 @@ static void xe_hwmon_process_reg(struct xe_hwmon
> *hwmon, enum xe_hwmon_reg hwmon
>   */
>  static void xe_hwmon_power_max_read(struct xe_hwmon *hwmon, long
> *value)  {
> -	u64 reg_val, min, max;
> +	u64 reg_val = 0, min, max;
> 
>  	mutex_lock(&hwmon->hwmon_lock);
> 
> @@ -182,7 +182,7 @@ static void xe_hwmon_power_max_read(struct
> xe_hwmon *hwmon, long *value)  static int
> xe_hwmon_power_max_write(struct xe_hwmon *hwmon, long value)  {
>  	int ret = 0;
> -	u64 reg_val;
> +	u64 reg_val = 0;
> 
>  	mutex_lock(&hwmon->hwmon_lock);
> 
> @@ -212,7 +212,7 @@ static int xe_hwmon_power_max_write(struct
> xe_hwmon *hwmon, long value)
> 
>  static void xe_hwmon_power_rated_max_read(struct xe_hwmon *hwmon,
> long *value)  {
> -	u64 reg_val;
> +	u64 reg_val = 0;
> 
>  	xe_hwmon_process_reg(hwmon, REG_PKG_POWER_SKU,
> REG_READ32, &reg_val, 0, 0);
>  	reg_val = REG_FIELD_GET(PKG_TDP, reg_val); @@ -243,7 +243,7 @@
> static void  xe_hwmon_energy_get(struct xe_hwmon *hwmon, long *energy)  {
>  	struct xe_hwmon_energy_info *ei = &hwmon->ei;
> -	u64 reg_val;
> +	u64 reg_val = 0;
> 
>  	xe_hwmon_process_reg(hwmon, REG_PKG_ENERGY_STATUS,
> REG_READ32,
>  			     &reg_val, 0, 0);
> @@ -264,8 +264,8 @@ xe_hwmon_power1_max_interval_show(struct device
> *dev, struct device_attribute *a
>  				  char *buf)
>  {
>  	struct xe_hwmon *hwmon = dev_get_drvdata(dev);
> -	u32 x, y, x_w = 2; /* 2 bits */
> -	u64 r, tau4, out;
> +	u32 x = 0, y = 0, x_w = 2; /* 2 bits */
> +	u64 r = 0, tau4, out;
> 
>  	xe_pm_runtime_get(gt_to_xe(hwmon->gt));
> 
> @@ -291,7 +291,7 @@ xe_hwmon_power1_max_interval_show(struct device
> *dev, struct device_attribute *a
>  	 * As y can be < 2, we compute tau4 = (4 | x) << y
>  	 * and then add 2 when doing the final right shift to account for units
>  	 */
> -	tau4 = ((1 << x_w) | x) << y;
> +	tau4 = (u64)((1 << x_w) | x) << y;
> 
>  	/* val in hwmon interface units (millisec) */
>  	out = mul_u64_u32_shr(tau4, SF_TIME, hwmon->scl_shift_time + x_w);
> @@ -331,7 +331,7 @@ xe_hwmon_power1_max_interval_store(struct device
> *dev, struct device_attribute *
>  	r = FIELD_PREP(PKG_MAX_WIN, PKG_MAX_WIN_DEFAULT);
>  	x = REG_FIELD_GET(PKG_MAX_WIN_X, r);
>  	y = REG_FIELD_GET(PKG_MAX_WIN_Y, r);
> -	tau4 = ((1 << x_w) | x) << y;
> +	tau4 = (u64)((1 << x_w) | x) << y;
>  	max_win = mul_u64_u32_shr(tau4, SF_TIME, hwmon->scl_shift_time +
> x_w);
> 
>  	if (val > max_win)
> @@ -466,7 +466,7 @@ static int xe_hwmon_power_curr_crit_write(struct
> xe_hwmon *hwmon, long value, u3
> 
>  static void xe_hwmon_get_voltage(struct xe_hwmon *hwmon, long *value)  {
> -	u64 reg_val;
> +	u64 reg_val = 0;
> 
>  	xe_hwmon_process_reg(hwmon, REG_GT_PERF_STATUS,
>  			     REG_READ32, &reg_val, 0, 0);
> --
> 2.25.1