Add APIs to enable/disable a channel and switch to or preempt a specific TSG

Adds:
- /proc/preempt_tsg which takes a TSG ID
- /proc/disable_channel which takes a channel ID
- /proc/enable_channel which takes a channel ID
- /proc/switch_to_tsg which takes a TSG ID

Also significantly expands documentation and structs available in
nvdebug.h.

1 files changed, 135 insertions, 0 deletions

diff --git a/runlist_procfs.c b/runlist_procfs.c
index 183eab6..411f844 100644
--- a/runlist_procfs.c
+++ b/runlist_procfs.c
@@ -151,3 +151,138 @@ const struct file_operations runlist_file_ops = {
         .llseek = seq_lseek,
         .release = seq_release,
 };
+
+ssize_t preempt_tsg_file_write(struct file *f, const char __user *buffer,
+                               size_t count, loff_t *off) {
+        uint32_t target_tsgid;
+        // Passing 0 as the base to kstrtou32 indicates autodetect hex/octal/dec
+        int err = kstrtou32_from_user(buffer, count, 0, &target_tsgid);
+        if (err)
+                return err;
+
+        // TSG IDs are a 12-bit field, so make sure the request is in-range
+        if (target_tsgid > MAX_TSGID)
+                return -ERANGE;
+
+        // Execute preemption
+        err = preempt_tsg(target_tsgid);
+        if (err)
+                return err;
+
+        return count;
+}
+
+const struct file_operations preempt_tsg_file_ops = {
+        .write = preempt_tsg_file_write,
+};
+
+ssize_t disable_channel_file_write(struct file *f, const char __user *buffer,
+                                   size_t count, loff_t *off) {
+        uint32_t target_channel;
+        channel_ctrl_t chan;
+        int err;
+        struct gk20a *g = get_live_gk20a();
+        if (!g)
+                return -EIO;
+        // Passing 0 as the base to kstrtou32 indicates autodetect hex/octal/dec
+        err = kstrtou32_from_user(buffer, count, 0, &target_channel);
+        if (err)
+                return err;
+
+        if (target_channel > MAX_CHID)
+                return -ERANGE;
+
+        // Disable channel
+        chan.raw = nvdebug_readq(g, NV_PCCSR_CHANNEL_INST(target_channel));
+        chan.enable_clear = true;
+        nvdebug_writeq(g, NV_PCCSR_CHANNEL_INST(target_channel), chan.raw);
+
+        return count;
+}
+
+const struct file_operations disable_channel_file_ops = {
+        .write = disable_channel_file_write,
+};
+
+ssize_t enable_channel_file_write(struct file *f, const char __user *buffer,
+                                   size_t count, loff_t *off) {
+        uint32_t target_channel;
+        channel_ctrl_t chan;
+        int err;
+        struct gk20a *g = get_live_gk20a();
+        if (!g)
+                return -EIO;
+        // Passing 0 as the base to kstrtou32 indicates autodetect hex/octal/dec
+        err = kstrtou32_from_user(buffer, count, 0, &target_channel);
+        if (err)
+                return err;
+
+        if (target_channel > MAX_CHID)
+                return -ERANGE;
+
+        // Disable channel
+        chan.raw = nvdebug_readq(g, NV_PCCSR_CHANNEL_INST(target_channel));
+        chan.enable_set = true;
+        nvdebug_writeq(g, NV_PCCSR_CHANNEL_INST(target_channel), chan.raw);
+
+        return count;
+}
+
+const struct file_operations enable_channel_file_ops = {
+        .write = enable_channel_file_write,
+};
+
+ssize_t switch_to_tsg_file_write(struct file *f, const char __user *buffer,
+                                   size_t count, loff_t *off) {
+        uint32_t target_tsgid;
+        struct runlist_chan* chan;
+        channel_ctrl_t chan_ctl;
+        struct runlist_iter rl_iter;
+        int err;
+        loff_t pos = 0;
+        struct gk20a *g = get_live_gk20a();
+        if (!g)
+                return -EIO;
+        // Passing 0 as the base to kstrtou32 indicates autodetect hex/octal/dec
+        err = kstrtou32_from_user(buffer, count, 0, &target_tsgid);
+        if (err)
+                return err;
+
+        if (target_tsgid > MAX_TSGID)
+                return -ERANGE;
+
+        err = get_runlist_iter(&rl_iter);
+        if (err)
+                return err;
+
+        // Iterate through all TSGs
+        while (pos < rl_iter.rl_info.len) {
+                if (rl_iter.curr_tsg->tsgid == target_tsgid) {
+                        // Enable channels of target TSG
+                        for_chan_in_tsg(chan, rl_iter.curr_tsg) {
+                                chan_ctl.raw = nvdebug_readq(g, NV_PCCSR_CHANNEL_INST(chan->chid));
+                                chan_ctl.enable_set = true;
+                                nvdebug_writeq(g, NV_PCCSR_CHANNEL_INST(chan->chid), chan_ctl.raw);
+                        }
+                } else {
+                        // Disable all other channels
+                        for_chan_in_tsg(chan, rl_iter.curr_tsg) {
+                                chan_ctl.raw = nvdebug_readq(g, NV_PCCSR_CHANNEL_INST(chan->chid));
+                                chan_ctl.enable_clear = true;
+                                nvdebug_writeq(g, NV_PCCSR_CHANNEL_INST(chan->chid), chan_ctl.raw);
+                        }
+                }
+                pos += 1 + rl_iter.curr_tsg->tsg_length;
+                rl_iter.curr_tsg = next_tsg(rl_iter.curr_tsg);
+        }
+        // Switch to next TSG with active channels (should be our TSG)
+        err = preempt_tsg(target_tsgid);
+        if (err)
+                return err;
+
+        return count;
+}
+
+const struct file_operations switch_to_tsg_file_ops = {
+        .write = switch_to_tsg_file_write,
+};