gpu: nvgpu: tpc powergating through sysfs

- adds static tpc-powergating through sysfs.
- active tpc count will remain till the GPU/systems is not booted again.
- tpc_pg_mask can be written only after GPU probe finishes and
  GPU boot is triggered.

Note:
To be able to use this feature, we need to change boot/init
scripts of the OS(used with nvgpu driver) to write to sysfs nodes before
posting discover image size query to FECS.

Bug 200406784

Change-Id: Id749c7a617422c625f77d0c1a9aada2eb960c4d0
Signed-off-by: Deepak Goyal <dgoyal@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1742422
Reviewed-by: svc-misra-checker <svc-misra-checker@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Vijayakumar Subbu <vsubbu@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 59 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/os/linux/sysfs.c b/drivers/gpu/nvgpu/os/linux/sysfs.c
index 1b84e2e2..b607768a 100644
--- a/drivers/gpu/nvgpu/os/linux/sysfs.c
+++ b/drivers/gpu/nvgpu/os/linux/sysfs.c
@@ -31,6 +31,8 @@
 
 #define ROOTRW (S_IRWXU|S_IRGRP|S_IROTH)
 
+#define TPC_MASK_FOR_ALL_ACTIVE_TPCs           (u32) 0x0
+
 static ssize_t elcg_enable_store(struct device *dev,
         struct device_attribute *attr, const char *buf, size_t count)
 {
@@ -843,6 +845,61 @@ static ssize_t force_idle_read(struct device *dev,
 static DEVICE_ATTR(force_idle, ROOTRW, force_idle_read, force_idle_store);
 #endif
 
+static ssize_t tpc_pg_mask_read(struct device *dev,
+        struct device_attribute *attr, char *buf)
+{
+        struct gk20a *g = get_gk20a(dev);
+
+        return snprintf(buf, PAGE_SIZE, "%d\n", g->tpc_pg_mask);
+}
+
+static ssize_t tpc_pg_mask_store(struct device *dev,
+        struct device_attribute *attr, const char *buf, size_t count)
+{
+        struct gk20a *g = get_gk20a(dev);
+        struct gr_gk20a *gr = &g->gr;
+        unsigned long val = 0;
+
+        nvgpu_mutex_acquire(&g->tpc_pg_lock);
+
+        if (!g->can_tpc_powergate) {
+                nvgpu_info(g, "TPC-PG not enabled for the platform");
+                goto exit;
+        }
+
+        if (kstrtoul(buf, 10, &val) < 0) {
+                nvgpu_err(g, "invalid value");
+                nvgpu_mutex_release(&g->tpc_pg_lock);
+                return -EINVAL;
+        }
+
+        if (val == g->tpc_pg_mask) {
+                nvgpu_info(g, "no value change, same mask already set");
+                goto exit;
+        }
+
+        if (gr->ctx_vars.golden_image_size) {
+                nvgpu_err(g, "golden image size already initialized");
+                nvgpu_mutex_release(&g->tpc_pg_lock);
+                return -ENODEV;
+        }
+
+        if (val == TPC_MASK_FOR_ALL_ACTIVE_TPCs || val == g->valid_tpc_mask) {
+                g->tpc_pg_mask = val;
+        } else {
+
+                nvgpu_err(g, "TPC-PG mask is invalid");
+                nvgpu_mutex_release(&g->tpc_pg_lock);
+                return -EINVAL;
+        }
+exit:
+        nvgpu_mutex_release(&g->tpc_pg_lock);
+
+        return count;
+}
+
+static DEVICE_ATTR(tpc_pg_mask, ROOTRW, tpc_pg_mask_read, tpc_pg_mask_store);
+
 static ssize_t tpc_fs_mask_store(struct device *dev,
         struct device_attribute *attr, const char *buf, size_t count)
 {
@@ -1130,6 +1187,7 @@ void nvgpu_remove_sysfs(struct device *dev)
         device_remove_file(dev, &dev_attr_aelpg_enable);
         device_remove_file(dev, &dev_attr_allow_all);
         device_remove_file(dev, &dev_attr_tpc_fs_mask);
+        device_remove_file(dev, &dev_attr_tpc_pg_mask);
         device_remove_file(dev, &dev_attr_min_timeslice_us);
         device_remove_file(dev, &dev_attr_max_timeslice_us);
 
@@ -1181,6 +1239,7 @@ int nvgpu_create_sysfs(struct device *dev)
         error |= device_create_file(dev, &dev_attr_aelpg_enable);
         error |= device_create_file(dev, &dev_attr_allow_all);
         error |= device_create_file(dev, &dev_attr_tpc_fs_mask);
+        error |= device_create_file(dev, &dev_attr_tpc_pg_mask);
         error |= device_create_file(dev, &dev_attr_min_timeslice_us);
         error |= device_create_file(dev, &dev_attr_max_timeslice_us);