Commit 37d52e44 authored by Vinay Belgaumkar's avatar Vinay Belgaumkar Committed by John Harrison
Browse files

drm/i915/slpc: Use platform limits for min/max frequency 

GuC will set the min/max frequencies to theoretical max on
ATS-M. This will break kernel ABI, so limit min/max frequency
to RP0(platform max) instead.

Also modify the SLPC selftest to update the min frequency
when we have a server part so that we can iterate between
platform min and max.

v2: Check softlimits instead of platform limits (Riana)
v3: More review comments (Ashutosh)
v4: No need to use saved_min_freq and other comments (Ashutosh)

Bug: https://gitlab.freedesktop.org/drm/intel/-/issues/7030



Acked-by: default avatarNirmoy Das <nirmoy.das@intel.com>
Reviewed-by: default avatarRiana Tauro <riana.tauro@intel.com>
Signed-off-by: default avatarVinay Belgaumkar <vinay.belgaumkar@intel.com>
Reviewed-by: default avatarAshutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: default avatarJohn Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221024225453.4856-1-vinay.belgaumkar@intel.com
parent f864a29a

drivers/gpu/drm/i915/gt/selftest_slpc.c

+11 −9
Original line number Diff line number Diff line
@@ -239,6 +239,11 @@ static int run_test(struct intel_gt *gt, int test_type) 
	if (!intel_uc_uses_guc_slpc(&gt->uc))

		return 0;



	if (slpc->min_freq == slpc->rp0_freq) {

		pr_err("Min/Max are fused to the same value\n");

		return -EINVAL;

	}



	if (igt_spinner_init(&spin, gt))

		return -ENOMEM;
@@ -253,17 +258,14 @@ static int run_test(struct intel_gt *gt, int test_type) 
	}



	/*

	 * FIXME: With efficient frequency enabled, GuC can request

	 * frequencies higher than the SLPC max. While this is fixed

	 * in GuC, we level set these tests with RPn as min.

	 * Set min frequency to RPn so that we can test the whole

	 * range of RPn-RP0. This also turns off efficient freq

	 * usage and makes results more predictable.

	 */

	err = slpc_set_min_freq(slpc, slpc->min_freq);

	if (err)

	if (err) {

		pr_err("Unable to update min freq!");

		return err;



	if (slpc->min_freq == slpc->rp0_freq) {

		pr_err("Min/Max are fused to the same value\n");

		return -EINVAL;

	}



	intel_gt_pm_wait_for_idle(gt);
@@ -330,7 +332,7 @@ static int run_test(struct intel_gt *gt, int test_type) 
				engine->name, max_act_freq);



			/* Actual frequency should rise above min */

			if (max_act_freq <= slpc_min_freq) {

			if (max_act_freq <= slpc->min_freq) {

				pr_err("Actual freq did not rise above min\n");

				pr_err("Perf Limit Reasons: 0x%x\n",

				       intel_uncore_read(gt->uncore, GT0_PERF_LIMIT_REASONS));

drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c

+37 −0
Original line number Diff line number Diff line
@@ -263,6 +263,7 @@ int intel_guc_slpc_init(struct intel_guc_slpc *slpc) 


	slpc->max_freq_softlimit = 0;

	slpc->min_freq_softlimit = 0;

	slpc->min_is_rpmax = false;



	slpc->boost_freq = 0;

	atomic_set(&slpc->num_waiters, 0);
@@ -588,6 +589,39 @@ static int slpc_set_softlimits(struct intel_guc_slpc *slpc) 
	return 0;

}



static bool is_slpc_min_freq_rpmax(struct intel_guc_slpc *slpc)

{

	struct drm_i915_private *i915 = slpc_to_i915(slpc);

	int slpc_min_freq;

	int ret;



	ret = intel_guc_slpc_get_min_freq(slpc, &slpc_min_freq);

	if (ret) {

		drm_err(&i915->drm,

			"Failed to get min freq: (%d)\n",

			ret);

		return false;

	}



	if (slpc_min_freq == SLPC_MAX_FREQ_MHZ)

		return true;

	else

		return false;

}



static void update_server_min_softlimit(struct intel_guc_slpc *slpc)

{

	/* For server parts, SLPC min will be at RPMax.

	 * Use min softlimit to clamp it to RP0 instead.

	 */

	if (!slpc->min_freq_softlimit &&

	    is_slpc_min_freq_rpmax(slpc)) {

		slpc->min_is_rpmax = true;

		slpc->min_freq_softlimit = slpc->rp0_freq;

		(slpc_to_gt(slpc))->defaults.min_freq = slpc->min_freq_softlimit;

	}

}



static int slpc_use_fused_rp0(struct intel_guc_slpc *slpc)

{

	/* Force SLPC to used platform rp0 */
@@ -647,6 +681,9 @@ int intel_guc_slpc_enable(struct intel_guc_slpc *slpc) 


	slpc_get_rp_values(slpc);



	/* Handle the case where min=max=RPmax */

	update_server_min_softlimit(slpc);



	/* Set SLPC max limit to RP0 */

	ret = slpc_use_fused_rp0(slpc);

	if (unlikely(ret)) {

drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.h

+2 −0
Original line number Diff line number Diff line
@@ -9,6 +9,8 @@ 
#include "intel_guc_submission.h"

#include "intel_guc_slpc_types.h"



#define SLPC_MAX_FREQ_MHZ 4250



struct intel_gt;

struct drm_printer;

drivers/gpu/drm/i915/gt/uc/intel_guc_slpc_types.h

+3 −0
Original line number Diff line number Diff line
@@ -19,6 +19,9 @@ struct intel_guc_slpc { 
	bool supported;

	bool selected;



	/* Indicates this is a server part */

	bool min_is_rpmax;



	/* platform frequency limits */

	u32 min_freq;

	u32 rp0_freq;