Re: [V9 6/9] drm/amd/pm: setup the framework to support Wifi RFI mitigation feature

Lazar, Lijo
2023-08-18T09:13:10Z

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@amd.com>
> Reviewed-by: Mario Limonciello <mario.limonciello@amd.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.

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