drm/i915: Report requested frequency alongside current frequency in debugfs

It can be useful to compare at times the current vs requested frequency
of the GPU, so provide the contents of RPNSWREQ alonside CAGF.

Signed-off-by: Chris Wilson <[e-mail]>
Reviewed-by: Rodrigo Vivi <[e-mail]>
Signed-off-by: Daniel Vetter <[e-mail]>

drivers/gpu/drm/i915/i915_debugfs.c

···
 		u32 gt_perf_status = I915_READ(GEN6_GT_PERF_STATUS);
 		u32 rp_state_limits = I915_READ(GEN6_RP_STATE_LIMITS);
 		u32 rp_state_cap = I915_READ(GEN6_RP_STATE_CAP);
-		u32 rpstat, cagf;
+		u32 rpstat, cagf, reqf;
 		u32 rpupei, rpcurup, rpprevup;
 		u32 rpdownei, rpcurdown, rpprevdown;
 		int max_freq;
···
 			return ret;
 
 		gen6_gt_force_wake_get(dev_priv);
+
+		reqf = I915_READ(GEN6_RPNSWREQ);
+		reqf &= ~GEN6_TURBO_DISABLE;
+		if (IS_HASWELL(dev))
+			reqf >>= 24;
+		else
+			reqf >>= 25;
+		reqf *= GT_FREQUENCY_MULTIPLIER;
 
 		rpstat = I915_READ(GEN6_RPSTAT1);
 		rpupei = I915_READ(GEN6_RP_CUR_UP_EI);
···
 			   gt_perf_status & 0xff);
 		seq_printf(m, "Render p-state limit: %d\n",
 			   rp_state_limits & 0xff);
+		seq_printf(m, "RPNSWREQ: %dMHz\n", reqf);
 		seq_printf(m, "CAGF: %dMHz\n", cagf);
 		seq_printf(m, "RP CUR UP EI: %dus\n", rpupei &
 			   GEN6_CURICONT_MASK);