gpu: nvgpu: delete nvgpu_semaphore_int list

The hw semas in a sema pool are stored in a list. All elements in this
list are freed in a loop when a semaphore pool is destroyed. However,
each hw sema is always owned by a channel, and each such channel frees
its hw sema during channel closure before putting a ref to the VM which
holds a ref to the sema pool, so the lifetime of all the hw semas is
shorter than that of the pool and this list is always empty when freeing
the pool. Delete the list and this freeing loop.

Meanwhile delete also the nr_incrs member in nvgpu_semaphore_int that is
never accessed.

Jira NVGPU-512

Change-Id: Ie072029f9e7cc749141e9f02ef45fdf64358ad96
Signed-off-by: Konsta Holtta <kholtta@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1653540
Reviewed-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-by: svc-mobile-coverity <svc-mobile-coverity@nvidia.com>
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-by: Alex Waterman <alexw@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, 1 insertions, 11 deletions

diff --git a/drivers/gpu/nvgpu/common/semaphore.c b/drivers/gpu/nvgpu/common/semaphore.c
index 72b8a04c..e1e6c027 100644
--- a/drivers/gpu/nvgpu/common/semaphore.c
+++ b/drivers/gpu/nvgpu/common/semaphore.c
@@ -1,7 +1,7 @@
 /*
  * Nvgpu Semaphores
  *
- * Copyright (c) 2014-2017, NVIDIA CORPORATION.  All rights reserved.
+ * Copyright (c) 2014-2018, NVIDIA CORPORATION.  All rights reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
@@ -165,7 +165,6 @@ struct nvgpu_semaphore_pool *nvgpu_semaphore_pool_alloc(
 
         p->page_idx = page_idx;
         p->sema_sea = sea;
-        nvgpu_init_list_node(&p->hw_semas);
         nvgpu_init_list_node(&p->pool_list_entry);
         nvgpu_ref_init(&p->ref);
 
@@ -301,7 +300,6 @@ static void nvgpu_semaphore_pool_free(struct nvgpu_ref *ref)
         struct nvgpu_semaphore_pool *p =
                 container_of(ref, struct nvgpu_semaphore_pool, ref);
         struct nvgpu_semaphore_sea *s = p->sema_sea;
-        struct nvgpu_semaphore_int *hw_sema, *tmp;
 
         /* Freeing a mapped pool is a bad idea. */
         WARN_ON(p->mapped || p->gpu_va || p->gpu_va_ro);
@@ -312,10 +310,6 @@ static void nvgpu_semaphore_pool_free(struct nvgpu_ref *ref)
         s->page_count--;
         __unlock_sema_sea(s);
 
-        nvgpu_list_for_each_entry_safe(hw_sema, tmp, &p->hw_semas,
-                                nvgpu_semaphore_int, hw_sema_list)
-                nvgpu_kfree(p->sema_sea->gk20a, hw_sema);
-
         nvgpu_mutex_destroy(&p->pool_lock);
 
         gpu_sema_dbg(pool_to_gk20a(p),
@@ -376,11 +370,8 @@ static int __nvgpu_init_hw_sema(struct channel_gk20a *ch)
         hw_sema->idx = hw_sema_idx;
         hw_sema->offset = SEMAPHORE_SIZE * hw_sema_idx;
         nvgpu_atomic_set(&hw_sema->next_value, 0);
-        nvgpu_init_list_node(&hw_sema->hw_sema_list);
         nvgpu_mem_wr(ch->g, &p->rw_mem, hw_sema->offset, 0);
 
-        nvgpu_list_add(&hw_sema->hw_sema_list, &p->hw_semas);
-
         nvgpu_mutex_release(&p->pool_lock);
 
         return 0;
@@ -406,7 +397,6 @@ void nvgpu_semaphore_free_hw_sema(struct channel_gk20a *ch)
         clear_bit(ch->hw_sema->idx, p->semas_alloced);
 
         /* Make sure that when the ch is re-opened it will get a new HW sema. */
-        nvgpu_list_del(&ch->hw_sema->hw_sema_list);
         nvgpu_kfree(ch->g, ch->hw_sema);
         ch->hw_sema = NULL;