8 files changed, 59 insertions, 39 deletions

diff --git a/drivers/gpu/nvgpu/common/fifo/channel.c b/drivers/gpu/nvgpu/common/fifo/channel.c
index 54fa4747..45c02a75 100644
--- a/drivers/gpu/nvgpu/common/fifo/channel.c
+++ b/drivers/gpu/nvgpu/common/fifo/channel.c
@@ -626,6 +626,18 @@ void _gk20a_channel_put(struct channel_gk20a *ch, const char *caller)
         WARN_ON(nvgpu_atomic_read(&ch->ref_count) == 0 && ch->referenceable);
 }
 
+struct channel_gk20a *_gk20a_channel_from_id(struct gk20a *g, u32 chid,
+                                         const char *caller)
+{
+        nvgpu_log_fn(g, " ");
+
+        if (chid == FIFO_INVAL_CHANNEL_ID) {
+                return NULL;
+        }
+
+        return _gk20a_channel_get(&g->fifo.channel[chid], caller);
+}
+
 void gk20a_channel_close(struct channel_gk20a *ch)
 {
         gk20a_free_channel(ch, false);
@@ -1450,11 +1462,10 @@ void gk20a_channel_timeout_restart_all_channels(struct gk20a *g)
         u32 chid;
 
         for (chid = 0; chid < f->num_channels; chid++) {
-                struct channel_gk20a *ch = &f->channel[chid];
+                struct channel_gk20a *ch = gk20a_channel_from_id(g, chid);
 
-                if (gk20a_channel_get(ch) == NULL) {
+                if (ch == NULL)
                         continue;
-                }
 
                 nvgpu_raw_spinlock_acquire(&ch->timeout.lock);
                 if (ch->timeout.running) {
@@ -1553,9 +1564,9 @@ static void gk20a_channel_poll_timeouts(struct gk20a *g)
 
 
         for (chid = 0; chid < g->fifo.num_channels; chid++) {
-                struct channel_gk20a *ch = &g->fifo.channel[chid];
+                struct channel_gk20a *ch = gk20a_channel_from_id(g, chid);
 
-                if (gk20a_channel_get(ch)) {
+                if (ch != NULL) {
                         gk20a_channel_timeout_check(ch);
                         gk20a_channel_put(ch);
                 }
@@ -2107,9 +2118,9 @@ void gk20a_channel_deterministic_idle(struct gk20a *g)
         nvgpu_rwsem_down_write(&g->deterministic_busy);
 
         for (chid = 0; chid < f->num_channels; chid++) {
-                struct channel_gk20a *ch = &f->channel[chid];
+                struct channel_gk20a *ch = gk20a_channel_from_id(g, chid);
 
-                if (gk20a_channel_get(ch) == NULL) {
+                if (ch == NULL) {
                         continue;
                 }
 
@@ -2145,9 +2156,9 @@ void gk20a_channel_deterministic_unidle(struct gk20a *g)
         u32 chid;
 
         for (chid = 0; chid < f->num_channels; chid++) {
-                struct channel_gk20a *ch = &f->channel[chid];
+                struct channel_gk20a *ch = gk20a_channel_from_id(g, chid);
 
-                if (gk20a_channel_get(ch) == NULL) {
+                if (ch == NULL) {
                         continue;
                 }
 
@@ -2256,8 +2267,9 @@ int gk20a_channel_suspend(struct gk20a *g)
         nvgpu_log_fn(g, " ");
 
         for (chid = 0; chid < f->num_channels; chid++) {
-                struct channel_gk20a *ch = &f->channel[chid];
-                if (gk20a_channel_get(ch) != NULL) {
+                struct channel_gk20a *ch = gk20a_channel_from_id(g, chid);
+
+                if (ch != NULL) {
                         nvgpu_log_info(g, "suspend channel %d", chid);
                         /* disable channel */
                         gk20a_disable_channel_tsg(g, ch);
@@ -2280,9 +2292,11 @@ int gk20a_channel_suspend(struct gk20a *g)
                 gk20a_fifo_update_runlist_ids(g, active_runlist_ids, ~0, false, true);
 
                 for (chid = 0; chid < f->num_channels; chid++) {
-                        if (gk20a_channel_get(&f->channel[chid])) {
-                                g->ops.fifo.unbind_channel(&f->channel[chid]);
-                                gk20a_channel_put(&f->channel[chid]);
+                        struct channel_gk20a *ch = gk20a_channel_from_id(g, chid);
+
+                        if (ch != NULL) {
+                                g->ops.fifo.unbind_channel(ch);
+                                gk20a_channel_put(ch);
                         }
                 }
         }
@@ -2301,12 +2315,14 @@ int gk20a_channel_resume(struct gk20a *g)
         nvgpu_log_fn(g, " ");
 
         for (chid = 0; chid < f->num_channels; chid++) {
-                if (gk20a_channel_get(&f->channel[chid])) {
+                struct channel_gk20a *ch = gk20a_channel_from_id(g, chid);
+
+                if (ch != NULL) {
                         nvgpu_log_info(g, "resume channel %d", chid);
-                        g->ops.fifo.bind_channel(&f->channel[chid]);
+                        g->ops.fifo.bind_channel(ch);
                         channels_in_use = true;
                         active_runlist_ids |= BIT(f->channel[chid].runlist_id);
-                        gk20a_channel_put(&f->channel[chid]);
+                        gk20a_channel_put(ch);
                 }
         }
 
diff --git a/drivers/gpu/nvgpu/gk20a/fifo_gk20a.c b/drivers/gpu/nvgpu/gk20a/fifo_gk20a.c
index 9691d51b..f4a4591d 100644
--- a/drivers/gpu/nvgpu/gk20a/fifo_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/fifo_gk20a.c
@@ -1172,7 +1172,7 @@ gk20a_refch_from_inst_ptr(struct gk20a *g, u64 inst_ptr)
                 struct channel_gk20a *ch;
                 u64 ch_inst_ptr;
 
-                ch = gk20a_channel_get(&f->channel[ci]);
+                ch = gk20a_channel_from_id(g, ci);
                 /* only alive channels are searched */
                 if (!ch) {
                         continue;
@@ -1959,9 +1959,9 @@ void gk20a_fifo_recover_ch(struct gk20a *g, u32 chid, bool verbose, int rc_type)
                 gk20a_fifo_recover(g, engines, chid, false, true, verbose,
                                         rc_type);
         } else {
-                struct channel_gk20a *ch = &g->fifo.channel[chid];
+                struct channel_gk20a *ch = gk20a_channel_from_id(g, chid);
 
-                if (gk20a_channel_get(ch)) {
+                if (ch != NULL) {
                         gk20a_channel_abort(ch, false);
 
                         if (gk20a_fifo_error_ch(g, ch)) {
@@ -2710,9 +2710,9 @@ static void gk20a_fifo_pbdma_fault_rc(struct gk20a *g,
         id = fifo_pbdma_status_id_v(status);
         if (fifo_pbdma_status_id_type_v(status)
                         == fifo_pbdma_status_id_type_chid_v()) {
-                struct channel_gk20a *ch = &f->channel[id];
+                struct channel_gk20a *ch = gk20a_channel_from_id(g, id);
 
-                if (gk20a_channel_get(ch)) {
+                if (ch != NULL) {
                         g->ops.fifo.set_error_notifier(ch, error_notifier);
                         gk20a_fifo_recover_ch(g, id, true, RC_TYPE_PBDMA_FAULT);
                         gk20a_channel_put(ch);
@@ -2924,12 +2924,12 @@ void gk20a_fifo_preempt_timeout_rc(struct gk20a *g, u32 id,
                 gk20a_fifo_recover_tsg(g, id, true,
                                                 RC_TYPE_PREEMPT_TIMEOUT);
         } else {
-                struct channel_gk20a *ch = &g->fifo.channel[id];
+                struct channel_gk20a *ch = gk20a_channel_from_id(g, id);
 
                 nvgpu_err(g,
                         "preempt channel %d timeout", id);
 
-                if (gk20a_channel_get(ch)) {
+                if (ch != NULL) {
                         g->ops.fifo.set_error_notifier(ch,
                                         NVGPU_ERR_NOTIFIER_FIFO_ERROR_IDLE_TIMEOUT);
                         gk20a_fifo_recover_ch(g, id, true,
@@ -4031,8 +4031,8 @@ void gk20a_debug_dump_all_channel_status_ramfc(struct gk20a *g,
         }
 
         for (chid = 0; chid < f->num_channels; chid++) {
-                struct channel_gk20a *ch = &f->channel[chid];
-                if (gk20a_channel_get(ch)) {
+                struct channel_gk20a *ch = gk20a_channel_from_id(g, chid);
+                if (ch != NULL) {
                         ch_state[chid] =
                                 nvgpu_kmalloc(g, sizeof(struct ch_state) +
                                         ram_in_alloc_size_v());
diff --git a/drivers/gpu/nvgpu/gk20a/gr_gk20a.c b/drivers/gpu/nvgpu/gk20a/gr_gk20a.c
index 8cb66279..928d80cb 100644
--- a/drivers/gpu/nvgpu/gk20a/gr_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/gr_gk20a.c
@@ -5581,15 +5581,16 @@ static struct channel_gk20a *gk20a_gr_get_channel_from_ctx(
                 if (gr->chid_tlb[i].curr_ctx == curr_ctx) {
                         chid = gr->chid_tlb[i].chid;
                         tsgid = gr->chid_tlb[i].tsgid;
-                        ret = gk20a_channel_get(&f->channel[chid]);
+                        ret = gk20a_channel_from_id(g, chid);
                         goto unlock;
                 }
         }
 
         /* slow path */
         for (chid = 0; chid < f->num_channels; chid++) {
-                struct channel_gk20a *ch = &f->channel[chid];
-                if (gk20a_channel_get(ch) == NULL) {
+                struct channel_gk20a *ch = gk20a_channel_from_id(g, chid);
+
+                if (ch == NULL) {
                         continue;
                 }
 
diff --git a/drivers/gpu/nvgpu/gp10b/gr_gp10b.c b/drivers/gpu/nvgpu/gp10b/gr_gp10b.c
index f70a5a00..a3655146 100644
--- a/drivers/gpu/nvgpu/gp10b/gr_gp10b.c
+++ b/drivers/gpu/nvgpu/gp10b/gr_gp10b.c
@@ -1961,8 +1961,8 @@ static int gr_gp10b_get_cilp_preempt_pending_chid(struct gk20a *g, int *__chid)
 
         chid = g->gr.cilp_preempt_pending_chid;
 
-        ch = gk20a_channel_get(gk20a_fifo_channel_from_chid(g, chid));
-        if (!ch) {
+        ch = gk20a_channel_from_id(g, chid);
+        if (ch == NULL) {
                 return ret;
         }
 
@@ -2014,9 +2014,8 @@ int gr_gp10b_handle_fecs_error(struct gk20a *g,
                         goto clean_up;
                 }
 
-                ch = gk20a_channel_get(
-                                gk20a_fifo_channel_from_chid(g, chid));
-                if (!ch) {
+                ch = gk20a_channel_from_id(g, chid);
+                if (ch == NULL) {
                         goto clean_up;
                 }
 
diff --git a/drivers/gpu/nvgpu/include/nvgpu/channel.h b/drivers/gpu/nvgpu/include/nvgpu/channel.h
index 6cdcb973..1851b9e2 100644
--- a/drivers/gpu/nvgpu/include/nvgpu/channel.h
+++ b/drivers/gpu/nvgpu/include/nvgpu/channel.h
@@ -393,6 +393,11 @@ struct channel_gk20a *__must_check _gk20a_channel_get(struct channel_gk20a *ch,
 void _gk20a_channel_put(struct channel_gk20a *ch, const char *caller);
 #define gk20a_channel_put(ch) _gk20a_channel_put(ch, __func__)
 
+/* returns NULL if could not take a ref to the channel */
+struct channel_gk20a *__must_check _gk20a_channel_from_id(struct gk20a *g,
+                u32 chid, const char *caller);
+#define gk20a_channel_from_id(g, chid) _gk20a_channel_from_id(g, chid, __func__)
+
 int gk20a_wait_channel_idle(struct channel_gk20a *ch);
 
 /* runlist_id -1 is synonym for ENGINE_GR_GK20A runlist id */
diff --git a/drivers/gpu/nvgpu/vgpu/fifo_vgpu.c b/drivers/gpu/nvgpu/vgpu/fifo_vgpu.c
index aa5abec9..8821e799 100644
--- a/drivers/gpu/nvgpu/vgpu/fifo_vgpu.c
+++ b/drivers/gpu/nvgpu/vgpu/fifo_vgpu.c
@@ -721,8 +721,7 @@ static void vgpu_fifo_set_ctx_mmu_error_ch_tsg(struct gk20a *g,
 
 int vgpu_fifo_isr(struct gk20a *g, struct tegra_vgpu_fifo_intr_info *info)
 {
-        struct fifo_gk20a *f = &g->fifo;
-        struct channel_gk20a *ch = gk20a_channel_get(&f->channel[info->chid]);
+        struct channel_gk20a *ch = gk20a_channel_from_id(g, info->chid);
 
         nvgpu_log_fn(g, " ");
         if (!ch)
diff --git a/drivers/gpu/nvgpu/vgpu/gr_vgpu.c b/drivers/gpu/nvgpu/vgpu/gr_vgpu.c
index 9fafa52f..6a86c9a0 100644
--- a/drivers/gpu/nvgpu/vgpu/gr_vgpu.c
+++ b/drivers/gpu/nvgpu/vgpu/gr_vgpu.c
@@ -953,10 +953,10 @@ int vgpu_init_gr_support(struct gk20a *g)
 
 int vgpu_gr_isr(struct gk20a *g, struct tegra_vgpu_gr_intr_info *info)
 {
-        struct fifo_gk20a *f = &g->fifo;
-        struct channel_gk20a *ch = gk20a_channel_get(&f->channel[info->chid]);
+        struct channel_gk20a *ch = gk20a_channel_from_id(g, info->chid);
 
         nvgpu_log_fn(g, " ");
+
         if (!ch)
                 return 0;
 
diff --git a/drivers/gpu/nvgpu/vgpu/vgpu.c b/drivers/gpu/nvgpu/vgpu/vgpu.c
index 266b801e..07361afe 100644
--- a/drivers/gpu/nvgpu/vgpu/vgpu.c
+++ b/drivers/gpu/nvgpu/vgpu/vgpu.c
@@ -119,7 +119,7 @@ static void vgpu_handle_channel_event(struct gk20a *g,
 
 static void vgpu_channel_abort_cleanup(struct gk20a *g, u32 chid)
 {
-        struct channel_gk20a *ch = gk20a_channel_get(&g->fifo.channel[chid]);
+        struct channel_gk20a *ch = gk20a_channel_from_id(g, chid);
 
         if (ch == NULL) {
                 nvgpu_err(g, "invalid channel id %d", chid);