gpu: nvgpu: support for clk.measure_freq for igpu

Add support for the measure_freq clock op for igpu:
  - add nvgpu_clk_measure_freq(), which in turn calls
    the get_rate() clock op.
  - Initialize the measure_freq clock op to nvgpu_clk_measure_freq()
    for native linux and vgpu.

JIRA ESRM-398

Change-Id: I8a3b2ee79e29e3491a16f55281494f05cd841b07
Signed-off-by: Peter Daifuku <pdaifuku@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1850585
Reviewed-by: svc-misra-checker <svc-misra-checker@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Debarshi Dutta <ddutta@nvidia.com>
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Nirav Patel <nipatel@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

drivers/gpu/nvgpu/clk/clk_arb.c

@@ -1049,6 +1049,20 @@ int nvgpu_clk_arb_get_arbiter_actual_mhz(struct gk20a *g,
 	return err;
 }
 
+unsigned long nvgpu_clk_measure_freq(struct gk20a *g, u32 api_domain)
+{
+	unsigned long freq = 0UL;
+
+	switch (api_domain) {
+	case CTRL_CLK_DOMAIN_GPC2CLK:
+		freq = g->ops.clk.get_rate(g, CTRL_CLK_DOMAIN_GPCCLK) * 2UL;
+		break;
+	default:
+		break;
+	}
+	return freq;
+}
+
 int nvgpu_clk_arb_get_arbiter_effective_mhz(struct gk20a *g,
 		u32 api_domain, u16 *freq_mhz)
 {

drivers/gpu/nvgpu/include/nvgpu/clk_arb.h

@@ -369,6 +369,8 @@ void nvgpu_clk_notification_queue_free(struct gk20a *g,
 
 void nvgpu_clk_arb_event_post_event(struct nvgpu_clk_dev *dev);
 
+unsigned long nvgpu_clk_measure_freq(struct gk20a *g, u32 api_domain);
+
 #ifdef CONFIG_DEBUG_FS
 int nvgpu_clk_arb_debugfs_init(struct gk20a *g);
 #endif

drivers/gpu/nvgpu/os/linux/clk.c

@@ -26,6 +26,7 @@
 #include "platform_gk20a.h"
 
 #include <nvgpu/gk20a.h>
+#include <nvgpu/clk_arb.h>
 
 #define HZ_TO_MHZ(x) ((x) / 1000000)
 
@@ -280,4 +281,5 @@ void nvgpu_linux_init_clk_support(struct gk20a *g)
 	g->ops.clk.clk_domain_get_f_points = nvgpu_linux_clk_get_f_points;
 	g->ops.clk.get_clk_range = nvgpu_clk_get_range;
 	g->ops.clk.clk_get_round_rate = nvgpu_clk_get_round_rate;
+	g->ops.clk.measure_freq = nvgpu_clk_measure_freq;
 }

drivers/gpu/nvgpu/vgpu/clk_vgpu.c

@@ -22,6 +22,7 @@
 
 #include <nvgpu/vgpu/vgpu.h>
 #include <nvgpu/vgpu/vgpu_ivc.h>
+#include <nvgpu/clk_arb.h>
 
 #include "gk20a/gk20a.h"
 #include "clk_vgpu.h"
@@ -214,6 +215,7 @@ void vgpu_init_clk_support(struct gk20a *g)
 	g->ops.clk.clk_get_round_rate = vgpu_clk_get_round_rate;
 	g->ops.clk.get_clk_range = vgpu_clk_get_range;
 	g->ops.clk.clk_domain_get_f_points = vgpu_clk_get_f_points;
+	g->ops.clk.measure_freq = nvgpu_clk_measure_freq;
 }
 
 int vgpu_clk_get_freqs(struct gk20a *g, unsigned long **freqs_out,