[v1,2/3] drm/amd/pm: send the SMT-enable message to pmfw

[Limonciello, Mario]

On 3/22/2023 00:48, Wenyou Yang wrote:
> When the CPU SMT status change in the fly, sent the SMT-enable
> message to pmfw to notify it that the SMT status changed.
> 
> Signed-off-by: Wenyou Yang <WenYou.Yang at amd.com>
> ---
>   drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c     | 41 +++++++++++++++++++
>   drivers/gpu/drm/amd/pm/swsmu/inc/amdgpu_smu.h |  5 +++
>   2 files changed, 46 insertions(+)
> 
> diff --git a/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c b/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
> index b5d64749990e..5cd85a9d149d 100644
> --- a/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
> +++ b/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
> @@ -22,6 +22,7 @@
>   
>   #define SWSMU_CODE_LAYER_L1
>   
> +#include <linux/cpu.h>
>   #include <linux/firmware.h>
>   #include <linux/pci.h>
>   
> @@ -69,6 +70,14 @@ static int smu_set_fan_speed_rpm(void *handle, uint32_t speed);
>   static int smu_set_gfx_cgpg(struct smu_context *smu, bool enabled);
>   static int smu_set_mp1_state(void *handle, enum pp_mp1_state mp1_state);
>   
> +static int smt_notifier_callback(struct notifier_block *nb, unsigned long action, void *data);
> +
> +extern struct raw_notifier_head smt_notifier_head;
> +
> +static struct notifier_block smt_notifier = {
> +	.notifier_call = smt_notifier_callback,
> +};
> +
>   static int smu_sys_get_pp_feature_mask(void *handle,
>   				       char *buf)
>   {
> @@ -625,6 +634,8 @@ static int smu_set_funcs(struct amdgpu_device *adev)
>   	return 0;
>   }
>   
> +static struct smu_context *current_smu;
> +
>   static int smu_early_init(void *handle)
>   {
>   	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
> @@ -645,6 +656,7 @@ static int smu_early_init(void *handle)
>   	mutex_init(&smu->message_lock);
>   
>   	adev->powerplay.pp_handle = smu;
> +	current_smu = smu;
>   	adev->powerplay.pp_funcs = &swsmu_pm_funcs;
>   
>   	r = smu_set_funcs(adev);
> @@ -1105,6 +1117,8 @@ static int smu_sw_init(void *handle)
>   	if (!smu->ppt_funcs->get_fan_control_mode)
>   		smu->adev->pm.no_fan = true;
>   
> +	raw_notifier_chain_register(&smt_notifier_head, &smt_notifier);
> +
>   	return 0;
>   }
>   
> @@ -1122,6 +1136,8 @@ static int smu_sw_fini(void *handle)
>   
>   	smu_fini_microcode(smu);
>   
> +	raw_notifier_chain_unregister(&smt_notifier_head, &smt_notifier);
> +
>   	return 0;
>   }
>   
> @@ -3241,3 +3257,28 @@ int smu_send_hbm_bad_channel_flag(struct smu_context *smu, uint32_t size)
>   
>   	return ret;
>   }
> +
> +static int smu_set_cpu_smt_enable(struct smu_context *smu, bool enable)
> +{
> +	int ret = -EINVAL;
> +
> +	if (smu->ppt_funcs && smu->ppt_funcs->set_cpu_smt_enable)
> +		ret = smu->ppt_funcs->set_cpu_smt_enable(smu, enable);
> +
> +	return ret;
> +}
> +
> +static int smt_notifier_callback(struct notifier_block *nb,
> +				 unsigned long action, void *data)
> +{
> +	struct smu_context *smu = current_smu;
> +	int ret = NOTIFY_OK;

This initialization is pointless, it's clobbered in the next line.

> +
> +	ret = (action == SMT_ENABLED) ?
> +				smu_set_cpu_smt_enable(smu, true) :
> +				smu_set_cpu_smt_enable(smu, false);

How about this instead, it should be more readable:

	ret = smu_set_cpu_smt_enable(smu, action == SMT_ENABLED);

> +	if (ret)
> +		ret = NOTIFY_BAD;
> +
> +	return ret;

How about instead:

	dev_dbg(adev->dev, "failed to %sable SMT: %d\n", action == SMT_ENABLED 
? "en" : "dis", ret);

	return ret ? NOTIFY_BAD : NOTIFY_OK;

> +}
> diff --git a/drivers/gpu/drm/amd/pm/swsmu/inc/amdgpu_smu.h b/drivers/gpu/drm/amd/pm/swsmu/inc/amdgpu_smu.h
> index 09469c750a96..7c6594bba796 100644
> --- a/drivers/gpu/drm/amd/pm/swsmu/inc/amdgpu_smu.h
> +++ b/drivers/gpu/drm/amd/pm/swsmu/inc/amdgpu_smu.h
> @@ -1354,6 +1354,11 @@ struct pptable_funcs {
>   	 * @init_pptable_microcode: Prepare the pptable microcode to upload via PSP
>   	 */
>   	int (*init_pptable_microcode)(struct smu_context *smu);
> +
> +	/**
> +	 * @set_cpu_smt_enable: Set the CPU SMT status
> +	 */
> +	int (*set_cpu_smt_enable)(struct smu_context *smu, bool enable);
>   };
>   
>   typedef enum {