gpu: nvgpu: add supported preemptions to gpu characteristics

Add below flag fields to gpu characteristics to indicate
supported and default preemption modes on platform for
graphics and compute

__u32 graphics_preemption_mode_flags;
__u32 compute_preemption_mode_flags;
__u32 default_graphics_preempt_mode;
__u32 default_compute_preempt_mode;

Add struct nvgpu_preemption_modes_rec to struct gr_gk20a
to store these values locally

Use platform specific get_preemption_mode_flags() to
get the flags and define gk20a/gm20b specific
get_preemption_mode_flags() API

Bug 1646259

Change-Id: I80193c0d988dc93bd96585f9aa631fd817f4dfa3
Signed-off-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-on: http://git-master/r/1133595
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Tested-by: Terje Bergstrom <tbergstrom@nvidia.com>

drivers/gpu/nvgpu/gk20a/gk20a.c

@@ -2142,6 +2142,17 @@ int gk20a_init_gpu_characteristics(struct gk20a *g)
 	if (platform->clk_round_rate)
 		gpu->max_freq = platform->clk_round_rate(g->dev, UINT_MAX);
 
+	g->ops.gr.get_preemption_mode_flags(g, &g->gr.preemption_mode_rec);
+	gpu->graphics_preemption_mode_flags =
+		g->gr.preemption_mode_rec.graphics_preemption_mode_flags;
+	gpu->compute_preemption_mode_flags =
+		g->gr.preemption_mode_rec.compute_preemption_mode_flags;
+	gpu->default_graphics_preempt_mode =
+		g->gr.preemption_mode_rec.default_graphics_preempt_mode;
+	gpu->default_compute_preempt_mode =
+		g->gr.preemption_mode_rec.default_compute_preempt_mode;
+
+
 	return 0;
 }
 

drivers/gpu/nvgpu/gk20a/gk20a.h

@@ -257,6 +257,8 @@ struct gpu_ops {
 		int (*set_preemption_mode)(struct channel_gk20a *ch,
 				u32 graphics_preempt_mode,
 				u32 compute_preempt_mode);
+		int (*get_preemption_mode_flags)(struct gk20a *g,
+		       struct nvgpu_preemption_modes_rec *preemption_modes_rec);
 	} gr;
 	const char *name;
 	struct {

drivers/gpu/nvgpu/gk20a/gr_gk20a.c

@@ -8659,6 +8659,22 @@ clean_up:
 	return err;
 }
 
+static int gr_gk20a_get_preemption_mode_flags(struct gk20a *g,
+		struct nvgpu_preemption_modes_rec *preemption_modes_rec)
+{
+	preemption_modes_rec->graphics_preemption_mode_flags =
+			NVGPU_GRAPHICS_PREEMPTION_MODE_WFI;
+	preemption_modes_rec->compute_preemption_mode_flags =
+			NVGPU_COMPUTE_PREEMPTION_MODE_WFI;
+
+	preemption_modes_rec->default_graphics_preempt_mode =
+			NVGPU_GRAPHICS_PREEMPTION_MODE_WFI;
+	preemption_modes_rec->default_compute_preempt_mode =
+			NVGPU_COMPUTE_PREEMPTION_MODE_WFI;
+
+	return 0;
+}
+
 void gk20a_init_gr_ops(struct gpu_ops *gops)
 {
 	gops->gr.access_smpc_reg = gr_gk20a_access_smpc_reg;
@@ -8726,4 +8742,5 @@ void gk20a_init_gr_ops(struct gpu_ops *gops)
 	gops->gr.update_sm_error_state = gk20a_gr_update_sm_error_state;
 	gops->gr.clear_sm_error_state = gk20a_gr_clear_sm_error_state;
 	gops->gr.suspend_contexts = gr_gk20a_suspend_contexts;
+	gops->gr.get_preemption_mode_flags = gr_gk20a_get_preemption_mode_flags;
 }

drivers/gpu/nvgpu/gk20a/gr_gk20a.h

@@ -188,6 +188,14 @@ struct gr_gk20a_isr_data {
 	u32 class_num;
 };
 
+struct nvgpu_preemption_modes_rec {
+	u32 graphics_preemption_mode_flags; /* supported preemption modes */
+	u32 compute_preemption_mode_flags; /* supported preemption modes */
+
+	u32 default_graphics_preempt_mode; /* default mode */
+	u32 default_compute_preempt_mode; /* default mode */
+};
+
 struct gr_gk20a {
 	struct gk20a *g;
 	struct {
@@ -325,6 +333,7 @@ struct gr_gk20a {
 	bool sw_ready;
 	bool skip_ucode_init;
 
+	struct nvgpu_preemption_modes_rec preemption_mode_rec;
 #ifdef CONFIG_ARCH_TEGRA_18x_SOC
 	struct gr_t18x t18x;
 #endif

drivers/gpu/nvgpu/gm20b/gr_gm20b.c

@@ -1345,6 +1345,23 @@ fail:
 	return err;
 }
 
+static int gr_gm20b_get_preemption_mode_flags(struct gk20a *g,
+		struct nvgpu_preemption_modes_rec *preemption_modes_rec)
+{
+	preemption_modes_rec->graphics_preemption_mode_flags =
+			NVGPU_GRAPHICS_PREEMPTION_MODE_WFI;
+	preemption_modes_rec->compute_preemption_mode_flags = (
+			NVGPU_COMPUTE_PREEMPTION_MODE_WFI |
+			NVGPU_COMPUTE_PREEMPTION_MODE_CTA);
+
+	preemption_modes_rec->default_graphics_preempt_mode =
+			NVGPU_GRAPHICS_PREEMPTION_MODE_WFI;
+	preemption_modes_rec->default_compute_preempt_mode =
+			NVGPU_COMPUTE_PREEMPTION_MODE_CTA;
+
+	return 0;
+}
+
 void gm20b_init_gr(struct gpu_ops *gops)
 {
 	gops->gr.init_gpc_mmu = gr_gm20b_init_gpc_mmu;
@@ -1417,4 +1434,5 @@ void gm20b_init_gr(struct gpu_ops *gops)
 	gops->gr.update_sm_error_state = gm20b_gr_update_sm_error_state;
 	gops->gr.clear_sm_error_state = gm20b_gr_clear_sm_error_state;
 	gops->gr.suspend_contexts = gr_gk20a_suspend_contexts;
+	gops->gr.get_preemption_mode_flags = gr_gm20b_get_preemption_mode_flags;
 }

include/uapi/linux/nvgpu.h

@@ -187,6 +187,13 @@ struct nvgpu_gpu_characteristics {
 
 	__u64 max_freq;
 
+	/* supported preemption modes */
+	__u32 graphics_preemption_mode_flags; /* NVGPU_GRAPHICS_PREEMPTION_MODE_* */
+	__u32 compute_preemption_mode_flags; /* NVGPU_COMPUTE_PREEMPTION_MODE_* */
+	/* default preemption modes */
+	__u32 default_graphics_preempt_mode; /* NVGPU_GRAPHICS_PREEMPTION_MODE_* */
+	__u32 default_compute_preempt_mode; /* NVGPU_COMPUTE_PREEMPTION_MODE_* */
+
 	/* Notes:
 	   - This struct can be safely appended with new fields. However, always
 	     keep the structure size multiple of 8 and make sure that the binary