[Intel-gfx] [PATCH] drm/i915/guc: Request RP0 before loading firmware

Ewins, Jon jon.ewins at intel.com
Tue Dec 21 18:11:57 UTC 2021


On 12/20/2021 3:52 PM, Sundaresan, Sujaritha wrote:
>
> On 12/16/2021 3:30 PM, Vinay Belgaumkar wrote:
>> By default, GT (and GuC) run at RPn. Requesting for RP0
>> before firmware load can speed up DMA and HuC auth as well.
>> In addition to writing to 0xA008, we also need to enable
>> swreq in 0xA024 so that Punit will pay heed to our request.
>>
>> SLPC will restore the frequency back to RPn after initialization,
>> but we need to manually do that for the non-SLPC path.
>>
>> We don't need a manual override in the SLPC disabled case, just
>> use the intel_rps_set function to ensure consistent RPS state.
>>
>> Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar at intel.com>
>> ---
>>   drivers/gpu/drm/i915/gt/intel_rps.c   | 59 +++++++++++++++++++++++++++
>>   drivers/gpu/drm/i915/gt/intel_rps.h   |  2 +
>>   drivers/gpu/drm/i915/gt/uc/intel_uc.c |  9 ++++
>>   drivers/gpu/drm/i915/i915_reg.h       |  4 ++
>>   4 files changed, 74 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/i915/gt/intel_rps.c 
>> b/drivers/gpu/drm/i915/gt/intel_rps.c
>> index 07ff7ba7b2b7..d576b34c7d6f 100644
>> --- a/drivers/gpu/drm/i915/gt/intel_rps.c
>> +++ b/drivers/gpu/drm/i915/gt/intel_rps.c
>> @@ -2226,6 +2226,65 @@ u32 intel_rps_read_state_cap(struct intel_rps 
>> *rps)
>>           return intel_uncore_read(uncore, GEN6_RP_STATE_CAP);
>>   }
>>   +static void intel_rps_set_manual(struct intel_rps *rps, bool enable)
>> +{
>> +    struct intel_uncore *uncore = rps_to_uncore(rps);
>> +    u32 state = enable ? GEN9_RPSWCTL_ENABLE : GEN9_RPSWCTL_DISABLE;
>> +
>> +    /* Allow punit to process software requests */
>> +    intel_uncore_write(uncore, GEN6_RP_CONTROL, state);
>> +}
> Was there a specific reason to remove the set/clear timer functions ?

Replying on behalf of Vinay Belguamkar:

We are now using the intel_rps_set() function which handles more state 
update in the correct rps path. We also obtain an rps lock which 
guarantees not clobbering rps data.  The set/clear timers were being 
done when we were modifying the frequency outside of the rps paths.  
rps_set_manual is now only called in the SLPC path where the rps timers 
are not even running.

>
>> +
>> +void intel_rps_raise_unslice(struct intel_rps *rps)
>> +{
>> +    struct intel_uncore *uncore = rps_to_uncore(rps);
>> +    u32 rp0_unslice_req;
>> +
>> +    mutex_lock(&rps->lock);
>> +
>> +    if (rps_uses_slpc(rps)) {
>> +        /* RP limits have not been initialized yet for SLPC path */
>> +        rp0_unslice_req = ((intel_rps_read_state_cap(rps) >> 0)
>> +                   & 0xff) * GEN9_FREQ_SCALER;
>> +
>> +        intel_rps_set_manual(rps, true);
>> +        intel_uncore_write(uncore, GEN6_RPNSWREQ,
>> +                   ((rp0_unslice_req <<
>> +                   GEN9_SW_REQ_UNSLICE_RATIO_SHIFT) |
>> +                   GEN9_IGNORE_SLICE_RATIO));
>> +        intel_rps_set_manual(rps, false);
>> +    } else {
>> +        intel_rps_set(rps, rps->rp0_freq);
>> +    }
>> +
>> +    mutex_unlock(&rps->lock);
>> +}
>> +
>> +void intel_rps_lower_unslice(struct intel_rps *rps)
>> +{
>> +    struct intel_uncore *uncore = rps_to_uncore(rps);
>> +    u32 rpn_unslice_req;
>> +
>> +    mutex_lock(&rps->lock);
>> +
>> +    if (rps_uses_slpc(rps)) {
>> +        /* RP limits have not been initialized yet for SLPC path */
>> +        rpn_unslice_req = ((intel_rps_read_state_cap(rps) >> 16)
>> +                   & 0xff) * GEN9_FREQ_SCALER;
>> +
>> +        intel_rps_set_manual(rps, true);
>> +        intel_uncore_write(uncore, GEN6_RPNSWREQ,
>> +                   ((rpn_unslice_req <<
>> +                   GEN9_SW_REQ_UNSLICE_RATIO_SHIFT) |
>> +                   GEN9_IGNORE_SLICE_RATIO));
>> +        intel_rps_set_manual(rps, false);
>> +    } else {
>> +        intel_rps_set(rps, rps->min_freq);
>> +    }
>> +
>> +    mutex_unlock(&rps->lock);
>> +}
>> +
> Small function name nitpick maybe unslice_freq ? Just a suggestion.
>>   /* External interface for intel_ips.ko */
>>     static struct drm_i915_private __rcu *ips_mchdev;
>> diff --git a/drivers/gpu/drm/i915/gt/intel_rps.h 
>> b/drivers/gpu/drm/i915/gt/intel_rps.h
>> index aee12f37d38a..c6d76a3d1331 100644
>> --- a/drivers/gpu/drm/i915/gt/intel_rps.h
>> +++ b/drivers/gpu/drm/i915/gt/intel_rps.h
>> @@ -45,6 +45,8 @@ u32 intel_rps_get_rpn_frequency(struct intel_rps 
>> *rps);
>>   u32 intel_rps_read_punit_req(struct intel_rps *rps);
>>   u32 intel_rps_read_punit_req_frequency(struct intel_rps *rps);
>>   u32 intel_rps_read_state_cap(struct intel_rps *rps);
>> +void intel_rps_raise_unslice(struct intel_rps *rps);
>> +void intel_rps_lower_unslice(struct intel_rps *rps);
>>     void gen5_rps_irq_handler(struct intel_rps *rps);
>>   void gen6_rps_irq_handler(struct intel_rps *rps, u32 pm_iir);
>> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_uc.c 
>> b/drivers/gpu/drm/i915/gt/uc/intel_uc.c
>> index 2fef3b0bbe95..3693c4e7dad0 100644
>> --- a/drivers/gpu/drm/i915/gt/uc/intel_uc.c
>> +++ b/drivers/gpu/drm/i915/gt/uc/intel_uc.c
>> @@ -8,6 +8,7 @@
>>   #include "intel_guc.h"
>>   #include "intel_guc_ads.h"
>>   #include "intel_guc_submission.h"
>> +#include "gt/intel_rps.h"
>>   #include "intel_uc.h"
>>     #include "i915_drv.h"
>> @@ -462,6 +463,8 @@ static int __uc_init_hw(struct intel_uc *uc)
>>       else
>>           attempts = 1;
>>   +    intel_rps_raise_unslice(&uc_to_gt(uc)->rps);
>> +
>>       while (attempts--) {
>>           /*
>>            * Always reset the GuC just before (re)loading, so
>> @@ -499,6 +502,9 @@ static int __uc_init_hw(struct intel_uc *uc)
>>           ret = intel_guc_slpc_enable(&guc->slpc);
>>           if (ret)
>>               goto err_submission;
>> +    } else {
>> +        /* Restore GT back to RPn for non-SLPC path */
>> +        intel_rps_lower_unslice(&uc_to_gt(uc)->rps);
>>       }
>>         drm_info(&i915->drm, "%s firmware %s version %u.%u %s:%s\n",
>> @@ -529,6 +535,9 @@ static int __uc_init_hw(struct intel_uc *uc)
>>   err_log_capture:
>>       __uc_capture_load_err_log(uc);
>>   err_out:
>> +    /* Return GT back to RPn */
>> +    intel_rps_lower_unslice(&uc_to_gt(uc)->rps);
>> +
>>       __uc_sanitize(uc);
>>         if (!ret) {
>> diff --git a/drivers/gpu/drm/i915/i915_reg.h 
>> b/drivers/gpu/drm/i915/i915_reg.h
>> index 1891e7fac39b..b2a86a26b843 100644
>> --- a/drivers/gpu/drm/i915/i915_reg.h
>> +++ b/drivers/gpu/drm/i915/i915_reg.h
>> @@ -9399,6 +9399,7 @@ enum {
>>   #define   GEN6_OFFSET(x)            ((x) << 19)
>>   #define   GEN6_AGGRESSIVE_TURBO            (0 << 15)
>>   #define   GEN9_SW_REQ_UNSLICE_RATIO_SHIFT    23
>> +#define   GEN9_IGNORE_SLICE_RATIO        (0 << 0)
>>     #define GEN6_RC_VIDEO_FREQ            _MMIO(0xA00C)
>>   #define GEN6_RC_CONTROL                _MMIO(0xA090)
>> @@ -9434,6 +9435,9 @@ enum {
>>   #define   GEN6_RP_UP_BUSY_CONT            (0x4 << 3)
>>   #define   GEN6_RP_DOWN_IDLE_AVG            (0x2 << 0)
>>   #define   GEN6_RP_DOWN_IDLE_CONT        (0x1 << 0)
>> +#define   GEN6_RPSWCTL_SHIFT            9
>> +#define   GEN9_RPSWCTL_ENABLE            (0x2 << GEN6_RPSWCTL_SHIFT)
>> +#define   GEN9_RPSWCTL_DISABLE            (0x0 << GEN6_RPSWCTL_SHIFT)
>>   #define GEN6_RP_UP_THRESHOLD            _MMIO(0xA02C)
>>   #define GEN6_RP_DOWN_THRESHOLD            _MMIO(0xA030)
>>   #define GEN6_RP_CUR_UP_EI            _MMIO(0xA050)
>
> Regards,
>
> Suja
>


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