gpu: nvgpu: replace input param chid with pointer to channel

preempt_channel needs to use the channel to pass it to other
public functions, get access to a tsg etc. This qualifies it to take a
pointer to a channel as an input parameter instead of a chid.

Increment the channel ref counter using the function
gk20a_channel_from_id in functions where we get the chid from the h/w
registers directly. Once the prempt_channel function call is done,
use a gk20a_channel_put on the referenced channel.

Jira NVGPU-1461

Change-Id: I6c87c8104cfcb418d468c8c590087fd4aeabf4bd
Signed-off-by: Debarshi Dutta <ddutta@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1963200
(cherry picked from commit 9abe9fe062367902ede7721cff55396859f8e4e8
in dev-kernel)
Reviewed-on: https://git-master.nvidia.com/r/2013728
Reviewed-by: svc-mobile-coverity <svc-mobile-coverity@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Bibek Basu <bbasu@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

2 files changed, 3 insertions, 5 deletions

diff --git a/drivers/gpu/nvgpu/vgpu/fifo_vgpu.c b/drivers/gpu/nvgpu/vgpu/fifo_vgpu.c
index 9e3f7867..234f6fd4 100644
--- a/drivers/gpu/nvgpu/vgpu/fifo_vgpu.c
+++ b/drivers/gpu/nvgpu/vgpu/fifo_vgpu.c
@@ -443,10 +443,8 @@ int vgpu_init_fifo_support(struct gk20a *g)
         return err;
 }
 
-int vgpu_fifo_preempt_channel(struct gk20a *g, u32 chid)
+int vgpu_fifo_preempt_channel(struct gk20a *g, struct channel_gk20a *ch)
 {
-        struct fifo_gk20a *f = &g->fifo;
-        struct channel_gk20a *ch = &f->channel[chid];
         struct tegra_vgpu_cmd_msg msg;
         struct tegra_vgpu_channel_config_params *p =
                         &msg.params.channel_config;
@@ -464,7 +462,7 @@ int vgpu_fifo_preempt_channel(struct gk20a *g, u32 chid)
 
         if (err || msg.ret) {
                 nvgpu_err(g,
-                        "preempt channel %d failed", chid);
+                        "preempt channel %d failed", ch->chid);
                 err = -ENOMEM;
         }
 
diff --git a/drivers/gpu/nvgpu/vgpu/fifo_vgpu.h b/drivers/gpu/nvgpu/vgpu/fifo_vgpu.h
index 8c042033..db199f8f 100644
--- a/drivers/gpu/nvgpu/vgpu/fifo_vgpu.h
+++ b/drivers/gpu/nvgpu/vgpu/fifo_vgpu.h
@@ -41,7 +41,7 @@ int vgpu_channel_setup_ramfc(struct channel_gk20a *ch, u64 gpfifo_base,
                                 u32 gpfifo_entries,
                                 unsigned long acquire_timeout, u32 flags);
 int vgpu_fifo_init_engine_info(struct fifo_gk20a *f);
-int vgpu_fifo_preempt_channel(struct gk20a *g, u32 chid);
+int vgpu_fifo_preempt_channel(struct gk20a *g, struct channel_gk20a *ch);
 int vgpu_fifo_preempt_tsg(struct gk20a *g, struct tsg_gk20a *tsg);
 int vgpu_fifo_update_runlist(struct gk20a *g, u32 runlist_id,
                                 u32 chid, bool add, bool wait_for_finish);