gpu: nvgpu: Do not pre-allocate cmdbuf entries

Do not preallocate cmdbuf tracking entries. Allocate them only when
needed.

Bug 200104160

Change-Id: I12f8392723c301a368af1e280893ff993480477f
Signed-off-by: Terje Bergstrom <tbergstrom@nvidia.com>
(cherry-picked from commit e7607f66c83bc7f16b9859ecdaa307432ea7a403)
Reviewed-on: http://git-master/r/745656
Reviewed-by: Automatic_Commit_Validation_User

diff --git a/drivers/gpu/nvgpu/gk20a/channel_gk20a.c b/drivers/gpu/nvgpu/gk20a/channel_gk20a.c
index 0b7a5b90592a69ab8b9153a603449e111b9e37d6..1a249cf3bfe738b7487661143f97424b79791f25 100644 (file)
--- a/drivers/gpu/nvgpu/gk20a/channel_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/channel_gk20a.c
@@ -861,8 +861,7 @@ static int channel_gk20a_alloc_priv_cmdbuf(struct channel_gk20a *c)
        struct device *d = dev_from_gk20a(c->g);
        struct vm_gk20a *ch_vm = c->vm;
        struct priv_cmd_queue *q = &c->priv_cmd_q;
-       struct priv_cmd_entry *e;
-       u32 i = 0, size;
+       u32 size;
        int err = 0;
        struct sg_table *sgt;
        dma_addr_t iova;
@@ -916,19 +915,6 @@ static int channel_gk20a_alloc_priv_cmdbuf(struct channel_gk20a *c)
        INIT_LIST_HEAD(&q->head);
        INIT_LIST_HEAD(&q->free);
 
-       /* pre-alloc 25% of priv cmdbuf entries and put them on free list */
-       for (i = 0; i < q->size / 4; i++) {
-               e = kzalloc(sizeof(struct priv_cmd_entry), GFP_KERNEL);
-               if (!e) {
-                       gk20a_err(d, "ch %d: fail to pre-alloc cmd entry",
-                               c->hw_chid);
-                       err = -ENOMEM;
-                       goto clean_up_sgt;
-               }
-               e->pre_alloc = true;
-               list_add(&e->list, &q->free);
-       }
-
        gk20a_free_sgtable(&sgt);
 
        return 0;
@@ -971,8 +957,7 @@ static void channel_gk20a_free_priv_cmdbuf(struct channel_gk20a *c)
        head = &q->free;
        list_for_each_safe(pos, tmp, head) {
                e = container_of(pos, struct priv_cmd_entry, list);
-               e->pre_alloc = false;
-               free_priv_cmdbuf(c, e);
+               kfree(e);
        }
 
        memset(q, 0, sizeof(struct priv_cmd_queue));
@@ -984,7 +969,6 @@ int gk20a_channel_alloc_priv_cmdbuf(struct channel_gk20a *c, u32 orig_size,
 {
        struct priv_cmd_queue *q = &c->priv_cmd_q;
        struct priv_cmd_entry *e;
-       struct list_head *node;
        u32 free_count;
        u32 size = orig_size;
        bool no_retry = false;
@@ -1013,22 +997,12 @@ TRY_AGAIN:
                        return -EAGAIN;
        }
 
-       if (unlikely(list_empty(&q->free))) {
-
-               gk20a_dbg_info("ch %d: run out of pre-alloc entries",
+       e = kzalloc(sizeof(struct priv_cmd_entry), GFP_KERNEL);
+       if (!e) {
+               gk20a_err(dev_from_gk20a(c->g),
+                       "ch %d: fail to allocate priv cmd entry",
                        c->hw_chid);
-
-               e = kzalloc(sizeof(struct priv_cmd_entry), GFP_KERNEL);
-               if (!e) {
-                       gk20a_err(dev_from_gk20a(c->g),
-                               "ch %d: fail to allocate priv cmd entry",
-                               c->hw_chid);
-                       return -ENOMEM;
-               }
-       } else  {
-               node = q->free.next;
-               list_del(node);
-               e = container_of(node, struct priv_cmd_entry, list);
+               return -ENOMEM;
        }
 
        e->size = orig_size;
@@ -1066,20 +1040,12 @@ TRY_AGAIN:
 static void free_priv_cmdbuf(struct channel_gk20a *c,
                             struct priv_cmd_entry *e)
 {
-       struct priv_cmd_queue *q = &c->priv_cmd_q;
-
        if (!e)
                return;
 
        list_del(&e->list);
 
-       if (unlikely(!e->pre_alloc))
-               kfree(e);
-       else {
-               memset(e, 0, sizeof(struct priv_cmd_entry));
-               e->pre_alloc = true;
-               list_add(&e->list, &q->free);
-       }
+       kfree(e);
 }
 
 /* free entries if they're no longer being used */

diff --git a/drivers/gpu/nvgpu/gk20a/mm_gk20a.h b/drivers/gpu/nvgpu/gk20a/mm_gk20a.h
index 5e7fe1c9faf49741d3a7b826ea6db89a32cb1b48..6b1d3f08945f4a9b9a9f29b607d869739ef23697 100644 (file)
--- a/drivers/gpu/nvgpu/gk20a/mm_gk20a.h
+++ b/drivers/gpu/nvgpu/gk20a/mm_gk20a.h
@@ -195,7 +195,6 @@ struct priv_cmd_entry {
        u32 gp_get;     /* gp_get when submitting last priv cmd */
        u32 gp_put;     /* gp_put when submitting last priv cmd */
        u32 gp_wrap;    /* wrap when submitting last priv cmd */
-       bool pre_alloc; /* prealloc entry, free to free list */
        struct list_head list;  /* node for lists */
 };