Message-ID:
 <DM6PR12MB2619F7FA653B9F87617A311AE4E3A@DM6PR12MB2619.namprd12.prod.outlook.com>
Date: Fri, 25 Aug 2023 08:48:40 +0000
From: "Quan, Evan" <Evan.Quan@....com>
To: "Lazar, Lijo" <Lijo.Lazar@....com>, "gregkh@...uxfoundation.org"
	<gregkh@...uxfoundation.org>, "rafael@...nel.org" <rafael@...nel.org>,
	"lenb@...nel.org" <lenb@...nel.org>, "johannes@...solutions.net"
	<johannes@...solutions.net>, "davem@...emloft.net" <davem@...emloft.net>,
	"edumazet@...gle.com" <edumazet@...gle.com>, "kuba@...nel.org"
	<kuba@...nel.org>, "pabeni@...hat.com" <pabeni@...hat.com>, "Deucher,
 Alexander" <Alexander.Deucher@....com>, "andrew@...n.ch" <andrew@...n.ch>,
	"rdunlap@...radead.org" <rdunlap@...radead.org>, "quic_jjohnson@...cinc.com"
	<quic_jjohnson@...cinc.com>, "horms@...nel.org" <horms@...nel.org>
CC: "linux-doc@...r.kernel.org" <linux-doc@...r.kernel.org>,
	"netdev@...r.kernel.org" <netdev@...r.kernel.org>,
	"linux-wireless@...r.kernel.org" <linux-wireless@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"amd-gfx@...ts.freedesktop.org" <amd-gfx@...ts.freedesktop.org>,
	"linux-acpi@...r.kernel.org" <linux-acpi@...r.kernel.org>, "Limonciello,
 Mario" <Mario.Limonciello@....com>
Subject: RE: [V9 6/9] drm/amd/pm: setup the framework to support Wifi RFI
 mitigation feature

[AMD Official Use Only - General]

> -----Original Message-----
> From: Lazar, Lijo <Lijo.Lazar@....com>
> Sent: Friday, August 18, 2023 5:12 PM
> To: Quan, Evan <Evan.Quan@....com>; gregkh@...uxfoundation.org;
> rafael@...nel.org; lenb@...nel.org; johannes@...solutions.net;
> davem@...emloft.net; edumazet@...gle.com; kuba@...nel.org;
> pabeni@...hat.com; Deucher, Alexander <Alexander.Deucher@....com>;
> andrew@...n.ch; rdunlap@...radead.org; quic_jjohnson@...cinc.com;
> horms@...nel.org
> Cc: linux-doc@...r.kernel.org; netdev@...r.kernel.org; linux-
> wireless@...r.kernel.org; linux-kernel@...r.kernel.org; amd-
> gfx@...ts.freedesktop.org; linux-acpi@...r.kernel.org; Limonciello, Mario
> <Mario.Limonciello@....com>
> Subject: Re: [V9 6/9] drm/amd/pm: setup the framework to support Wifi RFI
> mitigation feature
>
>
>
> On 8/18/2023 8:56 AM, 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)
> > ---
> >   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     | 194
> ++++++++++++++++++
> >   drivers/gpu/drm/amd/pm/swsmu/inc/amdgpu_smu.h |  23 +++
> >   drivers/gpu/drm/amd/pm/swsmu/smu_internal.h   |   3 +
> >   5 files changed, 239 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..704442ce1da3 100644
> > --- a/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
> > +++ b/drivers/gpu/drm/amd/pm/swsmu/amdgpu_smu.c
> > @@ -1228,6 +1228,173 @@ 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_out wbrf_exclusion = {0};
> > +   struct exclusion_range *wifi_bands = wbrf_exclusion.band_list;
> > +   struct amdgpu_device *adev = smu->adev;
> > +   uint64_t start, end;
> > +   int ret, i, j;
> > +
> > +   ret = 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 < MAX_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 = MAX_NUM_OF_WBRF_RANGES - 1; j > i; j--)
> > +                           if (wifi_bands[j].start &&
> > +                               wifi_bands[j].end)
> > +                                   break;
> > +
> > +                   if (j > i) {
> > +                           wifi_bands[i].start = wifi_bands[j].start;
> > +                           wifi_bands[i].end = wifi_bands[j].end;
>
> Since the last value is now 0, one way to optimize is to keep max as j
> -1 for the next iteration.
>
> > +                           wifi_bands[j].start = 0;
> > +                           wifi_bands[j].end = 0;
> > +                   }
> > +
> > +                   continue;
>
> If continued at this point, it won't eliminate all duplicates.
>
> Example:
> (2000,2100)(0,0)(1100,1200)(0, 0)(2500,2600)(3000,3200)(1100,1200)
>
> Once it places (1100,1200) at index 1, it will continue the loop and then it
> skips duplicate entry at index 2.
Thanks for pointing this out. Fixed in V10.

Evan
>
> Once replaced, you may assign the new start/end
>       start = wifi_bands[i].start = wifi_bands[j].start;
>       end= wifi_bands[i].end = wifi_bands[j].end;
>
> and then proceed to the duplicate entries scan loop below.
>
> > +           }
> > +
> > +           /* eliminate duplicate entries */
> > +           for (j = i + 1; j < MAX_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;
> > +                           continue;
>
> I think this'continue' is not required.
>
> Thanks,
> Lijo
>
> > +                   }
> > +           }
> > +   }
> > +
> > +   /* 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 &&
> > +                         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 = 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;
> > +
> > +   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
> > +1487,15 @@ 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 +1592,15 @@ 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 +1656,13 @@ 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 +1815,8 @@ 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..244297979f92 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/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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