gpu: nvgpu: refactor teardown to support unbind

This change refactors the teardown in remove to ensure that it is
possible to unload the driver while leaving fds open. This is achieved
by making sure that the SW state is kept alive till all fds are closed
and by checking that subsequent calls to ioctls after the teardown fail.

Normally, this would be achieved ny calls into gk20a_busy(), but in
kickoff we dont call into that to reduce latency, so we need to check
the driver status directly, and also in some of the functions
as we need to make sure the ioctl does not dereference the device or
platform struct

bug 200277762
JIRA: EVLR-1023

Change-Id: I163e47a08c29d4d5b3ab79f0eb531ef234f40bde
Signed-off-by: David Nieto <dmartineznie@nvidia.com>
Reviewed-on: http://git-master/r/1320219
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-by: svccoveritychecker <svccoveritychecker@nvidia.com>
Reviewed-by: Shreshtha Sahu <ssahu@nvidia.com>
Reviewed-by: Vijayakumar Subbu <vsubbu@nvidia.com>

1 files changed, 8 insertions, 13 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/mm_gk20a.c b/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
index 7b08387e..9e6dc74c 100644
--- a/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
@@ -809,7 +809,7 @@ static void gk20a_remove_mm_ce_support(struct mm_gk20a *mm)
         struct gk20a *g = gk20a_from_mm(mm);
 
         if (mm->vidmem.ce_ctx_id != (u32)~0)
-                gk20a_ce_delete_context(g->dev, mm->vidmem.ce_ctx_id);
+                gk20a_ce_delete_context_priv(g, mm->vidmem.ce_ctx_id);
 
         mm->vidmem.ce_ctx_id = (u32)~0;
 
@@ -1220,11 +1220,10 @@ static int alloc_gmmu_pages(struct vm_gk20a *vm, u32 order,
         u32 num_pages = 1 << order;
         u32 len = num_pages * PAGE_SIZE;
         int err;
-        struct gk20a_platform *platform = dev_get_drvdata(g->dev);
 
         gk20a_dbg_fn("");
 
-        if (platform->is_fmodel)
+        if (g->is_fmodel)
                 return alloc_gmmu_phys_pages(vm, order, entry);
 
         /*
@@ -1250,7 +1249,6 @@ void free_gmmu_pages(struct vm_gk20a *vm,
                      struct gk20a_mm_entry *entry)
 {
         struct gk20a *g = gk20a_from_vm(vm);
-        struct gk20a_platform *platform = dev_get_drvdata(g->dev);
 
         gk20a_dbg_fn("");
 
@@ -1260,7 +1258,7 @@ void free_gmmu_pages(struct vm_gk20a *vm,
         if (entry->woffset) /* fake shadow mem */
                 return;
 
-        if (platform->is_fmodel) {
+        if (g->is_fmodel) {
                 free_gmmu_phys_pages(vm, entry);
                 return;
         }
@@ -1270,11 +1268,9 @@ void free_gmmu_pages(struct vm_gk20a *vm,
 
 int map_gmmu_pages(struct gk20a *g, struct gk20a_mm_entry *entry)
 {
-        struct gk20a_platform *platform = dev_get_drvdata(g->dev);
-
         gk20a_dbg_fn("");
 
-        if (platform->is_fmodel)
+        if (g->is_fmodel)
                 return map_gmmu_phys_pages(entry);
 
         if (IS_ENABLED(CONFIG_ARM64)) {
@@ -1296,11 +1292,9 @@ int map_gmmu_pages(struct gk20a *g, struct gk20a_mm_entry *entry)
 
 void unmap_gmmu_pages(struct gk20a *g, struct gk20a_mm_entry *entry)
 {
-        struct gk20a_platform *platform = dev_get_drvdata(g->dev);
-
         gk20a_dbg_fn("");
 
-        if (platform->is_fmodel) {
+        if (g->is_fmodel) {
                 unmap_gmmu_phys_pages(entry);
                 return;
         }
@@ -4070,6 +4064,7 @@ static void gk20a_vm_remove_support_nofree(struct vm_gk20a *vm)
         struct mapped_buffer_node *mapped_buffer;
         struct vm_reserved_va_node *va_node, *va_node_tmp;
         struct rb_node *node;
+        struct gk20a *g = vm->mm->g;
 
         gk20a_dbg_fn("");
 
@@ -4078,7 +4073,7 @@ static void gk20a_vm_remove_support_nofree(struct vm_gk20a *vm)
          * pool involves unmapping a GMMU mapping which means aquiring the
          * update_gmmu_lock.
          */
-        if (!gk20a_platform_has_syncpoints(gk20a_from_vm(vm)->dev)) {
+        if (!(g->gpu_characteristics.flags & NVGPU_GPU_FLAGS_HAS_SYNCPOINTS)) {
                 if (vm->sema_pool) {
                         nvgpu_semaphore_pool_unmap(vm->sema_pool, vm);
                         nvgpu_semaphore_pool_put(vm->sema_pool);
@@ -4172,7 +4167,7 @@ static int gk20a_init_sema_pool(struct vm_gk20a *vm)
         /*
          * Don't waste the memory on semaphores if we don't need them.
          */
-        if (gk20a_platform_has_syncpoints(g->dev))
+        if (g->gpu_characteristics.flags & NVGPU_GPU_FLAGS_HAS_SYNCPOINTS)
                 return 0;
 
         if (vm->sema_pool)