Message-ID: <a45c6e51-0dbf-af27-1723-fb1477e6155d@amd.com>
Date:   Fri, 25 Aug 2023 19:39:03 +0530
From:   "Lazar, Lijo" <lijo.lazar@....com>
To:     Evan Quan <evan.quan@....com>, lenb@...nel.org,
        johannes@...solutions.net, davem@...emloft.net,
        edumazet@...gle.com, kuba@...nel.org, pabeni@...hat.com,
        alexander.deucher@....com, rafael@...nel.org,
        mario.limonciello@....com
Cc:     linux-kernel@...r.kernel.org, linux-acpi@...r.kernel.org,
        amd-gfx@...ts.freedesktop.org, dri-devel@...ts.freedesktop.org,
        linux-wireless@...r.kernel.org, netdev@...r.kernel.org
Subject: Re: [V10 5/8] drm/amd/pm: setup the framework to support Wifi RFI
 mitigation feature



On 8/25/2023 2:08 PM, Evan Quan wrote:
> With WBRF feature supported, as a driver responding to the frequencies,
> amdgpu driver is able to do shadow pstate switching to mitigate possible
> interference(between its (G-)DDR memory clocks and local radio module
> frequency bands used by Wifi 6/6e/7).
> 
> Signed-off-by: Evan Quan <evan.quan@....com>
> Reviewed-by: Mario Limonciello <mario.limonciello@....com>
> --
> v1->v2:
>    - update the prompt for feature support(Lijo)
> v8->v9:
>    - update parameter document for smu_wbrf_event_handler(Simon)
> v9->v10:
>   - correct the logics for wbrf range sorting(Lijo)
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu.h           |   2 +
>   drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c       |  17 ++
>   drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c     | 195 ++++++++++++++++++
>   drivers/gpu/drm/amd/pm/swsmu/inc/amdgpu_smu.h |  23 +++
>   drivers/gpu/drm/amd/pm/swsmu/smu_internal.h   |   3 +
>   5 files changed, 240 insertions(+)
> 
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> index a3b86b86dc47..2bfc9111ab00 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> @@ -247,6 +247,8 @@ extern int amdgpu_sg_display;
>   
>   extern int amdgpu_user_partt_mode;
>   
> +extern int amdgpu_wbrf;
> +
>   #define AMDGPU_VM_MAX_NUM_CTX			4096
>   #define AMDGPU_SG_THRESHOLD			(256*1024*1024)
>   #define AMDGPU_WAIT_IDLE_TIMEOUT_IN_MS	        3000
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> index 0593ef8fe0a6..1c574bd3b60d 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> @@ -195,6 +195,7 @@ int amdgpu_use_xgmi_p2p = 1;
>   int amdgpu_vcnfw_log;
>   int amdgpu_sg_display = -1; /* auto */
>   int amdgpu_user_partt_mode = AMDGPU_AUTO_COMPUTE_PARTITION_MODE;
> +int amdgpu_wbrf = -1;
>   
>   static void amdgpu_drv_delayed_reset_work_handler(struct work_struct *work);
>   
> @@ -981,6 +982,22 @@ module_param_named(user_partt_mode, amdgpu_user_partt_mode, uint, 0444);
>   module_param(enforce_isolation, bool, 0444);
>   MODULE_PARM_DESC(enforce_isolation, "enforce process isolation between graphics and compute . enforce_isolation = on");
>   
> +/**
> + * DOC: wbrf (int)
> + * Enable Wifi RFI interference mitigation feature.
> + * Due to electrical and mechanical constraints there may be likely interference of
> + * relatively high-powered harmonics of the (G-)DDR memory clocks with local radio
> + * module frequency bands used by Wifi 6/6e/7. To mitigate the possible RFI interference,
> + * with this feature enabled, PMFW will use either “shadowed P-State” or “P-State” based
> + * on active list of frequencies in-use (to be avoided) as part of initial setting or
> + * P-state transition. However, there may be potential performance impact with this
> + * feature enabled.
> + * (0 = disabled, 1 = enabled, -1 = auto (default setting, will be enabled if supported))
> + */
> +MODULE_PARM_DESC(wbrf,
> +	"Enable Wifi RFI interference mitigation (0 = disabled, 1 = enabled, -1 = auto(default)");
> +module_param_named(wbrf, amdgpu_wbrf, int, 0444);
> +
>   /* These devices are not supported by amdgpu.
>    * They are supported by the mach64, r128, radeon drivers
>    */
> diff --git a/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c b/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
> index ce41a8309582..bdfd234d1558 100644
> --- a/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
> +++ b/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
> @@ -1228,6 +1228,174 @@ static int smu_get_thermal_temperature_range(struct smu_context *smu)
>   	return ret;
>   }
>   
> +/**
> + * smu_wbrf_handle_exclusion_ranges - consume the wbrf exclusion ranges
> + *
> + * @smu: smu_context pointer
> + *
> + * Retrieve the wbrf exclusion ranges and send them to PMFW for proper handling.
> + * Returns 0 on success, error on failure.
> + */
> +static int smu_wbrf_handle_exclusion_ranges(struct smu_context *smu)
> +{
> +	struct wbrf_ranges_in_out wbrf_exclusion = {0};
> +	struct exclusion_range *wifi_bands = wbrf_exclusion.band_list;
> +	struct amdgpu_device *adev = smu->adev;
> +	uint32_t num_of_wbrf_ranges = MAX_NUM_OF_WBRF_RANGES;
> +	uint64_t start, end;
> +	int ret, i, j;
> +
> +	ret = acpi_amd_wbrf_retrieve_exclusions(adev->dev, &wbrf_exclusion);
> +	if (ret) {
> +		dev_err(adev->dev, "Failed to retrieve exclusion ranges!\n");
> +		return ret;
> +	}
> +
> +	/*
> +	 * The exclusion ranges array we got might be filled with holes and duplicate
> +	 * entries. For example:
> +	 * {(2400, 2500), (0, 0), (6882, 6962), (2400, 2500), (0, 0), (6117, 6189), (0, 0)...}
> +	 * We need to do some sortups to eliminate those holes and duplicate entries.
> +	 * Expected output: {(2400, 2500), (6117, 6189), (6882, 6962), (0, 0)...}
> +	 */
> +	for (i = 0; i < num_of_wbrf_ranges; i++) {
> +		start = wifi_bands[i].start;
> +		end = wifi_bands[i].end;
> +
> +		/* get the last valid entry to fill the intermediate hole */
> +		if (!start && !end) {
> +			for (j = num_of_wbrf_ranges - 1; j > i; j--)
> +				if (wifi_bands[j].start &&
> +				    wifi_bands[j].end)
> +					break;
> +
> +			/* no valid entry left */
> +			if (j <= i)
> +				break;
> +
> +			wifi_bands[i].start = wifi_bands[j].start;
> +			wifi_bands[i].end = wifi_bands[j].end;

start/end variables remain 0. Thus it won't have any effect on the loop 
below which looks for duplicates. start/end need to be reassigned here.

> +			wifi_bands[j].start = 0;
> +			wifi_bands[j].end = 0;
> +			num_of_wbrf_ranges--;

Instead of decrementing by 1, this can be kept equal to j - 1 as jth 
entry is 0 now.

Thanks,
Lijo

> +		}
> +
> +		/* eliminate duplicate entries */
> +		for (j = i + 1; j < num_of_wbrf_ranges; j++) {
> +			if ((wifi_bands[j].start == start) &&
> +			     (wifi_bands[j].end == end)) {
> +				wifi_bands[j].start = 0;
> +				wifi_bands[j].end = 0;
> +			}
> +		}
> +	}
> +
> +	/* Send the sorted wifi_bands to PMFW */
> +	ret = smu_set_wbrf_exclusion_ranges(smu, wifi_bands);
> +	/* Give it another chance */
> +	if (unlikely(ret == -EBUSY)) {
> +		mdelay(5);
> +		ret = smu_set_wbrf_exclusion_ranges(smu, wifi_bands);
> +	}
> +
> +	return ret;
> +}
> +
> +/**
> + * smu_wbrf_event_handler - handle notify events
> + *
> + * @nb: notifier block
> + * @action: event type
> + * @_arg: event data
> + *
> + * Calls relevant amdgpu function in response to wbrf event
> + * notification from kernel.
> + */
> +static int smu_wbrf_event_handler(struct notifier_block *nb,
> +				  unsigned long action, void *_arg)
> +{
> +	struct smu_context *smu = container_of(nb, struct smu_context,
> +					       wbrf_notifier);
> +
> +	switch (action) {
> +	case WBRF_CHANGED:
> +		smu_wbrf_handle_exclusion_ranges(smu);
> +		break;
> +	default:
> +		return NOTIFY_DONE;
> +	};
> +
> +	return NOTIFY_OK;
> +}
> +
> +/**
> + * smu_wbrf_support_check - check wbrf support
> + *
> + * @smu: smu_context pointer
> + *
> + * Verifies the ACPI interface whether wbrf is supported.
> + */
> +static void smu_wbrf_support_check(struct smu_context *smu)
> +{
> +	struct amdgpu_device *adev = smu->adev;
> +
> +	smu->wbrf_supported = smu_is_asic_wbrf_supported(smu) &&
> +			      !!amdgpu_wbrf &&
> +			      acpi_amd_wbrf_supported_consumer(adev->dev);
> +
> +	if (smu->wbrf_supported)
> +		dev_info(adev->dev, "RF interference mitigation is supported\n");
> +}
> +
> +/**
> + * smu_wbrf_init - init driver wbrf support
> + *
> + * @smu: smu_context pointer
> + *
> + * Verifies the AMD ACPI interfaces and registers with the wbrf
> + * notifier chain if wbrf feature is supported.
> + * Returns 0 on success, error on failure.
> + */
> +static int smu_wbrf_init(struct smu_context *smu)
> +{
> +	struct amdgpu_device *adev = smu->adev;
> +	int ret;
> +
> +	if (!smu->wbrf_supported)
> +		return 0;
> +
> +	smu->wbrf_notifier.notifier_call = smu_wbrf_event_handler;
> +	ret = acpi_amd_wbrf_register_notifier(&smu->wbrf_notifier);
> +	if (ret)
> +		return ret;
> +
> +	/*
> +	 * Some wifiband exclusion ranges may be already there
> +	 * before our driver loaded. To make sure our driver
> +	 * is awared of those exclusion ranges.
> +	 */
> +	ret = smu_wbrf_handle_exclusion_ranges(smu);
> +	if (ret)
> +		dev_err(adev->dev, "Failed to handle wbrf exclusion ranges\n");
> +
> +	return ret;
> +}
> +
> +/**
> + * smu_wbrf_fini - tear down driver wbrf support
> + *
> + * @smu: smu_context pointer
> + *
> + * Unregisters with the wbrf notifier chain.
> + */
> +static void smu_wbrf_fini(struct smu_context *smu)
> +{
> +	if (!smu->wbrf_supported)
> +		return;
> +
> +	acpi_amd_wbrf_unregister_notifier(&smu->wbrf_notifier);
> +}
> +
>   static int smu_smc_hw_setup(struct smu_context *smu)
>   {
>   	struct smu_feature *feature = &smu->smu_feature;
> @@ -1320,6 +1488,15 @@ static int smu_smc_hw_setup(struct smu_context *smu)
>   	if (ret)
>   		return ret;
>   
> +	/* Enable UclkShadow on wbrf supported */
> +	if (smu->wbrf_supported) {
> +		ret = smu_enable_uclk_shadow(smu, true);
> +		if (ret) {
> +			dev_err(adev->dev, "Failed to enable UclkShadow feature to support wbrf!\n");
> +			return ret;
> +		}
> +	}
> +
>   	/*
>   	 * With SCPM enabled, these actions(and relevant messages) are
>   	 * not needed and permitted.
> @@ -1416,6 +1593,15 @@ static int smu_smc_hw_setup(struct smu_context *smu)
>   	 */
>   	ret = smu_set_min_dcef_deep_sleep(smu,
>   					  smu->smu_table.boot_values.dcefclk / 100);
> +	if (ret) {
> +		dev_err(adev->dev, "Error setting min deepsleep dcefclk\n");
> +		return ret;
> +	}
> +
> +	/* Init wbrf support. Properly setup the notifier */
> +	ret = smu_wbrf_init(smu);
> +	if (ret)
> +		dev_err(adev->dev, "Error during wbrf init call\n");
>   
>   	return ret;
>   }
> @@ -1471,6 +1657,13 @@ static int smu_hw_init(void *handle)
>   		return ret;
>   	}
>   
> +	/*
> +	 * Check whether wbrf is supported. This needs to be done
> +	 * before SMU setup starts since part of SMU configuration
> +	 * relies on this.
> +	 */
> +	smu_wbrf_support_check(smu);
> +
>   	if (smu->is_apu) {
>   		ret = smu_set_gfx_imu_enable(smu);
>   		if (ret)
> @@ -1623,6 +1816,8 @@ static int smu_smc_hw_cleanup(struct smu_context *smu)
>   	struct amdgpu_device *adev = smu->adev;
>   	int ret = 0;
>   
> +	smu_wbrf_fini(smu);
> +
>   	cancel_work_sync(&smu->throttling_logging_work);
>   	cancel_work_sync(&smu->interrupt_work);
>   
> 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 6e2069dcb6b9..3eb1c72a76f1 100644
> --- a/drivers/gpu/drm/amd/pm/swsmu/inc/amdgpu_smu.h
> +++ b/drivers/gpu/drm/amd/pm/swsmu/inc/amdgpu_smu.h
> @@ -22,6 +22,8 @@
>   #ifndef __AMDGPU_SMU_H__
>   #define __AMDGPU_SMU_H__
>   
> +#include <linux/acpi_amd_wbrf.h>
> +
>   #include "amdgpu.h"
>   #include "kgd_pp_interface.h"
>   #include "dm_pp_interface.h"
> @@ -575,6 +577,10 @@ struct smu_context
>   	u32 debug_resp_reg;
>   
>   	struct delayed_work		swctf_delayed_work;
> +
> +	/* data structures for wbrf feature support */
> +	bool				wbrf_supported;
> +	struct notifier_block		wbrf_notifier;
>   };
>   
>   struct i2c_adapter;
> @@ -1356,6 +1362,23 @@ struct pptable_funcs {
>   	 * @init_pptable_microcode: Prepare the pptable microcode to upload via PSP
>   	 */
>   	int (*init_pptable_microcode)(struct smu_context *smu);
> +
> +	/**
> +	 * @is_asic_wbrf_supported: check whether PMFW supports the wbrf feature
> +	 */
> +	bool (*is_asic_wbrf_supported)(struct smu_context *smu);
> +
> +	/**
> +	 * @enable_uclk_shadow: Enable the uclk shadow feature on wbrf supported
> +	 */
> +	int (*enable_uclk_shadow)(struct smu_context *smu,
> +				  bool enablement);
> +
> +	/**
> +	 * @set_wbrf_exclusion_ranges: notify SMU the wifi bands occupied
> +	 */
> +	int (*set_wbrf_exclusion_ranges)(struct smu_context *smu,
> +					 struct exclusion_range *exclusion_ranges);
>   };
>   
>   typedef enum {
> diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu_internal.h b/drivers/gpu/drm/amd/pm/swsmu/smu_internal.h
> index ceb13c838067..67d7495ab49e 100644
> --- a/drivers/gpu/drm/amd/pm/swsmu/smu_internal.h
> +++ b/drivers/gpu/drm/amd/pm/swsmu/smu_internal.h
> @@ -97,6 +97,9 @@
>   #define smu_get_default_config_table_settings(smu, config_table)	smu_ppt_funcs(get_default_config_table_settings, -EOPNOTSUPP, smu, config_table)
>   #define smu_set_config_table(smu, config_table)				smu_ppt_funcs(set_config_table, -EOPNOTSUPP, smu, config_table)
>   #define smu_init_pptable_microcode(smu)					smu_ppt_funcs(init_pptable_microcode, 0, smu)
> +#define smu_is_asic_wbrf_supported(smu)					smu_ppt_funcs(is_asic_wbrf_supported, false, smu)
> +#define smu_enable_uclk_shadow(smu, enablement)				smu_ppt_funcs(enable_uclk_shadow, 0, smu, enablement)
> +#define smu_set_wbrf_exclusion_ranges(smu, exclusion_ranges)		smu_ppt_funcs(set_wbrf_exclusion_ranges, -EOPNOTSUPP, smu, exclusion_ranges)
>   
>   #endif
>   #endif

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