gpu: nvgpu: hal for timestamps correlation

In order to perform timestamps correlation for FECS
traces, we need to collect GPU / GPU timestamps
samples. In virtualization case, it is possible for
a guest to get GPU timestamps by using read_ptimer.
However, if the CPU timestamp is read on guest side,
and the GPU timestamp is read on vm-server side,
then it introduces some latency that will create an
artificial offset for GPU timestamps (~2 us in
average). For better CPU / GPU timestamps correlation,
Added a command to collect all timestamps on vm-server
side.

Bug 1900475

Change-Id: Idfdc6ae4c16c501dc5e00053a5b75932c55148d6
Signed-off-by: Thomas Fleury <tfleury@nvidia.com>
Reviewed-on: http://git-master/r/1472447
(cherry picked from commit 56f56b5cd9d2e75cf7d2613b5e115bfebdbee0ce)
Reviewed-on: http://git-master/r/1489183
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

6 files changed, 136 insertions, 60 deletions

diff --git a/drivers/gpu/nvgpu/common/linux/ioctl_ctrl.c b/drivers/gpu/nvgpu/common/linux/ioctl_ctrl.c
index 90a3fbd4..025a30fe 100644
--- a/drivers/gpu/nvgpu/common/linux/ioctl_ctrl.c
+++ b/drivers/gpu/nvgpu/common/linux/ioctl_ctrl.c
@@ -533,76 +533,34 @@ static int gk20a_ctrl_get_buffer_info(
                                         &args->out.id, &args->out.length);
 }
 
-static inline u64 get_cpu_timestamp_tsc(void)
-{
-        return ((u64) get_cycles());
-}
-
-static inline u64 get_cpu_timestamp_jiffies(void)
-{
-        return (get_jiffies_64() - INITIAL_JIFFIES);
-}
-
-static inline u64 get_cpu_timestamp_timeofday(void)
-{
-        struct timeval tv;
-
-        do_gettimeofday(&tv);
-        return timeval_to_jiffies(&tv);
-}
-
-static inline int get_timestamps_zipper(struct gk20a *g,
-                u64 (*get_cpu_timestamp)(void),
-                struct nvgpu_gpu_get_cpu_time_correlation_info_args *args)
-{
-        int err = 0;
-        unsigned int i = 0;
-
-        if (gk20a_busy(g)) {
-                nvgpu_err(g, "GPU not powered on");
-                err = -EINVAL;
-                goto end;
-        }
-
-        for (i = 0; i < args->count; i++) {
-                err = g->ops.bus.read_ptimer(g, &args->samples[i].gpu_timestamp);
-                if (err)
-                        return err;
-
-                args->samples[i].cpu_timestamp = get_cpu_timestamp();
-        }
-
-end:
-        gk20a_idle(g);
-        return err;
-}
-
 static int nvgpu_gpu_get_cpu_time_correlation_info(
         struct gk20a *g,
         struct nvgpu_gpu_get_cpu_time_correlation_info_args *args)
 {
-        int err = 0;
-        u64 (*get_cpu_timestamp)(void) = NULL;
+        struct nvgpu_cpu_time_correlation_sample *samples;
+        int err;
+        u32 i;
 
         if (args->count > NVGPU_GPU_GET_CPU_TIME_CORRELATION_INFO_MAX_COUNT)
                 return -EINVAL;
 
-        switch (args->source_id) {
-        case NVGPU_GPU_GET_CPU_TIME_CORRELATION_INFO_SRC_ID_TSC:
-                get_cpu_timestamp = get_cpu_timestamp_tsc;
-                break;
-        case NVGPU_GPU_GET_CPU_TIME_CORRELATION_INFO_SRC_ID_JIFFIES:
-                get_cpu_timestamp = get_cpu_timestamp_jiffies;
-                break;
-        case NVGPU_GPU_GET_CPU_TIME_CORRELATION_INFO_SRC_ID_TIMEOFDAY:
-                get_cpu_timestamp = get_cpu_timestamp_timeofday;
-                break;
-        default:
-                nvgpu_err(g, "invalid cpu clock source id");
-                return -EINVAL;
+        samples = nvgpu_kzalloc(g, args->count *
+                sizeof(struct nvgpu_cpu_time_correlation_sample));
+        if (!samples) {
+                return -ENOMEM;
         }
 
-        err = get_timestamps_zipper(g, get_cpu_timestamp, args);
+        err = g->ops.bus.get_timestamps_zipper(g,
+                        args->source_id, args->count, samples);
+        if (!err) {
+                for (i = 0; i < args->count; i++) {
+                        args->samples[i].cpu_timestamp = samples[i].cpu_timestamp;
+                        args->samples[i].gpu_timestamp = samples[i].gpu_timestamp;
+                }
+        }
+
+        nvgpu_kfree(g, samples);
+
         return err;
 }
 
diff --git a/drivers/gpu/nvgpu/gk20a/bus_gk20a.c b/drivers/gpu/nvgpu/gk20a/bus_gk20a.c
index 52ef08e4..7f0ca013 100644
--- a/drivers/gpu/nvgpu/gk20a/bus_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/bus_gk20a.c
@@ -128,6 +128,66 @@ int gk20a_read_ptimer(struct gk20a *g, u64 *value)
         return -EBUSY;
 }
 
+static inline u64 get_cpu_timestamp_tsc(void)
+{
+        return ((u64) get_cycles());
+}
+
+static inline u64 get_cpu_timestamp_jiffies(void)
+{
+        return (get_jiffies_64() - INITIAL_JIFFIES);
+}
+
+static inline u64 get_cpu_timestamp_timeofday(void)
+{
+        struct timeval tv;
+
+        do_gettimeofday(&tv);
+        return timeval_to_jiffies(&tv);
+}
+
+int gk20a_get_timestamps_zipper(struct gk20a *g,
+                u32 source_id, u32 count,
+                struct nvgpu_cpu_time_correlation_sample *samples)
+{
+        int err = 0;
+        unsigned int i = 0;
+        u64 (*get_cpu_timestamp)(void) = NULL;
+
+        switch (source_id) {
+        case NVGPU_GPU_GET_CPU_TIME_CORRELATION_INFO_SRC_ID_TSC:
+                get_cpu_timestamp = get_cpu_timestamp_tsc;
+                break;
+        case NVGPU_GPU_GET_CPU_TIME_CORRELATION_INFO_SRC_ID_JIFFIES:
+                get_cpu_timestamp = get_cpu_timestamp_jiffies;
+                break;
+        case NVGPU_GPU_GET_CPU_TIME_CORRELATION_INFO_SRC_ID_TIMEOFDAY:
+                get_cpu_timestamp = get_cpu_timestamp_timeofday;
+                break;
+        default:
+                nvgpu_err(g, "invalid cpu clock source id\n");
+                return -EINVAL;
+        }
+
+        if (gk20a_busy(g)) {
+                nvgpu_err(g, "GPU not powered on\n");
+                err = -EINVAL;
+                goto end;
+        }
+
+        for (i = 0; i < count; i++) {
+                err = g->ops.bus.read_ptimer(g, &samples[i].gpu_timestamp);
+                if (err)
+                        return err;
+
+                samples[i].cpu_timestamp = get_cpu_timestamp();
+        }
+
+end:
+        gk20a_idle(g);
+        return err;
+}
+
 static int gk20a_bus_bar1_bind(struct gk20a *g, struct nvgpu_mem *bar1_inst)
 {
         u64 iova = gk20a_mm_inst_block_addr(g, bar1_inst);
@@ -150,5 +210,6 @@ void gk20a_init_bus(struct gpu_ops *gops)
         gops->bus.init_hw = gk20a_bus_init_hw;
         gops->bus.isr = gk20a_bus_isr;
         gops->bus.read_ptimer = gk20a_read_ptimer;
+        gops->bus.get_timestamps_zipper = gk20a_get_timestamps_zipper;
         gops->bus.bar1_bind = gk20a_bus_bar1_bind;
 }
diff --git a/drivers/gpu/nvgpu/gk20a/bus_gk20a.h b/drivers/gpu/nvgpu/gk20a/bus_gk20a.h
index 72710c35..088c385e 100644
--- a/drivers/gpu/nvgpu/gk20a/bus_gk20a.h
+++ b/drivers/gpu/nvgpu/gk20a/bus_gk20a.h
@@ -22,10 +22,19 @@ struct gk20a;
 struct gpu_ops;
 struct nvgpu_mem;
 
+struct nvgpu_cpu_time_correlation_sample {
+        u64 cpu_timestamp;
+        u64 gpu_timestamp;
+};
+
 void gk20a_init_bus(struct gpu_ops *gops);
 
 void gk20a_bus_isr(struct gk20a *g);
 int gk20a_read_ptimer(struct gk20a *g, u64 *value);
 void gk20a_bus_init_hw(struct gk20a *g);
 
+int gk20a_get_timestamps_zipper(struct gk20a *g,
+                u32 source_id, u32 count,
+                struct nvgpu_cpu_time_correlation_sample *samples);
+
 #endif /* GK20A_H */
diff --git a/drivers/gpu/nvgpu/gk20a/gk20a.h b/drivers/gpu/nvgpu/gk20a/gk20a.h
index 34f89fc8..d1a55104 100644
--- a/drivers/gpu/nvgpu/gk20a/gk20a.h
+++ b/drivers/gpu/nvgpu/gk20a/gk20a.h
@@ -63,6 +63,7 @@ struct nvgpu_nvhost_dev;
 #include "priv_ring_gk20a.h"
 #include "therm_gk20a.h"
 #include "gm20b/acr_gm20b.h"
+#include "gk20a/bus_gk20a.h"
 #include "cde_gk20a.h"
 #include "sched_gk20a.h"
 #ifdef CONFIG_ARCH_TEGRA_18x_SOC
@@ -905,6 +906,9 @@ struct gpu_ops {
                 void (*init_hw)(struct gk20a *g);
                 void (*isr)(struct gk20a *g);
                 int (*read_ptimer)(struct gk20a *g, u64 *value);
+                int (*get_timestamps_zipper)(struct gk20a *g,
+                        u32 source_id, u32 count,
+                        struct nvgpu_cpu_time_correlation_sample *);
                 int (*bar1_bind)(struct gk20a *g, struct nvgpu_mem *bar1_inst);
         } bus;
 
diff --git a/drivers/gpu/nvgpu/gm20b/bus_gm20b.c b/drivers/gpu/nvgpu/gm20b/bus_gm20b.c
index 7b414196..39778c55 100644
--- a/drivers/gpu/nvgpu/gm20b/bus_gm20b.c
+++ b/drivers/gpu/nvgpu/gm20b/bus_gm20b.c
@@ -58,5 +58,6 @@ void gm20b_init_bus(struct gpu_ops *gops)
         gops->bus.init_hw = gk20a_bus_init_hw;
         gops->bus.isr = gk20a_bus_isr;
         gops->bus.read_ptimer = gk20a_read_ptimer;
+        gops->bus.get_timestamps_zipper = gk20a_get_timestamps_zipper;
         gops->bus.bar1_bind = gm20b_bus_bar1_bind;
 }
diff --git a/drivers/gpu/nvgpu/vgpu/vgpu.c b/drivers/gpu/nvgpu/vgpu/vgpu.c
index cdd0d378..a8c28826 100644
--- a/drivers/gpu/nvgpu/vgpu/vgpu.c
+++ b/drivers/gpu/nvgpu/vgpu/vgpu.c
@@ -367,6 +367,48 @@ static int vgpu_read_ptimer(struct gk20a *g, u64 *value)
         return err;
 }
 
+int vgpu_get_timestamps_zipper(struct gk20a *g,
+                u32 source_id, u32 count,
+                struct nvgpu_cpu_time_correlation_sample *samples)
+{
+        struct tegra_vgpu_cmd_msg msg = {0};
+        struct tegra_vgpu_get_timestamps_zipper_params *p =
+                        &msg.params.get_timestamps_zipper;
+        int err;
+        u32 i;
+
+        gk20a_dbg_fn("");
+
+        if (count > TEGRA_VGPU_GET_TIMESTAMPS_ZIPPER_MAX_COUNT) {
+                nvgpu_err(g, "count %u overflow", count);
+                return -EINVAL;
+        }
+
+        if (source_id != NVGPU_GPU_GET_CPU_TIME_CORRELATION_INFO_SRC_ID_TSC) {
+                nvgpu_err(g, "source_id %u not supported", source_id);
+                return -EINVAL;
+        }
+
+        msg.cmd = TEGRA_VGPU_CMD_GET_TIMESTAMPS_ZIPPER;
+        msg.handle = vgpu_get_handle(g);
+        p->source_id = TEGRA_VGPU_GET_TIMESTAMPS_ZIPPER_SRC_ID_TSC;
+        p->count = count;
+
+        err = vgpu_comm_sendrecv(&msg, sizeof(msg), sizeof(msg));
+        err = err ? err : msg.ret;
+        if (err) {
+                nvgpu_err(g, "vgpu get timestamps zipper failed, err=%d", err);
+                return err;
+        }
+
+        for (i = 0; i < count; i++) {
+                samples[i].cpu_timestamp = p->samples[i].cpu_timestamp;
+                samples[i].gpu_timestamp = p->samples[i].gpu_timestamp;
+        }
+
+        return err;
+}
+
 void vgpu_init_hal_common(struct gk20a *g)
 {
         struct gpu_ops *gops = &g->ops;
@@ -384,6 +426,7 @@ void vgpu_init_hal_common(struct gk20a *g)
 #endif
         gops->chip_init_gpu_characteristics = vgpu_init_gpu_characteristics;
         gops->bus.read_ptimer = vgpu_read_ptimer;
+        gops->bus.get_timestamps_zipper = vgpu_get_timestamps_zipper;
 }
 
 static int vgpu_init_hal(struct gk20a *g)