gpu: nvgpu: Free all page table levels

Convert the loop to free page tables into a recursive loop that goes
through all levels.

Change-Id: I3ab8f021bd8263f2f6dad29b5fbd0e6212c55a86
Signed-off-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-on: http://git-master/r/711393
Reviewed-on: http://git-master/r/737528
Reviewed-by: Alexander Van Brunt <avanbrunt@nvidia.com>
Tested-by: Alexander Van Brunt <avanbrunt@nvidia.com>
Reviewed-by: Automatic_Commit_Validation_User

1 files changed, 22 insertions, 17 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/mm_gk20a.c b/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
index 43758712..45f6fd64 100644
--- a/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
@@ -530,7 +530,9 @@ void free_gmmu_pages(struct vm_gk20a *vm,
         DEFINE_DMA_ATTRS(attrs);
 
         gk20a_dbg_fn("");
-        BUG_ON(entry->sgt == NULL);
+
+        if (!entry->sgt)
+                return;
 
         if (tegra_platform_is_linsim()) {
                 free_gmmu_phys_pages(vm, entry);
@@ -554,6 +556,7 @@ void free_gmmu_pages(struct vm_gk20a *vm,
                 entry->pages = NULL;
         }
         entry->size = 0;
+        entry->sgt = NULL;
 }
 
 int map_gmmu_pages(struct gk20a_mm_entry *entry)
@@ -2140,13 +2143,28 @@ void gk20a_vm_unmap(struct vm_gk20a *vm, u64 offset)
         mutex_unlock(&vm->update_gmmu_lock);
 }
 
+static void gk20a_vm_free_entries(struct vm_gk20a *vm,
+                                  struct gk20a_mm_entry *parent,
+                                  int level)
+{
+        const struct gk20a_mmu_level *l = &vm->mmu_levels[level];
+        int num_entries = 1 << (l->hi_bit[parent->pgsz] - l->lo_bit[parent->pgsz]);
+        int i;
+
+        if (parent->entries)
+                for (i = 0; i < num_entries; i++)
+                        gk20a_vm_free_entries(vm, &parent->entries[i], level+1);
+
+        if (parent->size)
+                free_gmmu_pages(vm, parent);
+        kfree(parent->entries);
+}
+
 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;
-        int i;
-        u32 pde_lo = 0, pde_hi = 0;
 
         gk20a_dbg_fn("");
         mutex_lock(&vm->update_gmmu_lock);
@@ -2169,17 +2187,6 @@ static void gk20a_vm_remove_support_nofree(struct vm_gk20a *vm)
                 kfree(va_node);
         }
 
-        /* unmapping all buffers above may not actually free
-         * all vm ptes.  jettison them here for certain... */
-        pde_range_from_vaddr_range(vm,
-                                   0, vm->va_limit-1,
-                                   &pde_lo, &pde_hi);
-        for (i = 0; i < pde_hi + 1; i++) {
-                struct gk20a_mm_entry *entry = &vm->pdb.entries[i];
-                if (entry->size)
-                        free_gmmu_pages(vm, entry);
-        }
-
         gk20a_deinit_vm(vm);
 
         mutex_unlock(&vm->update_gmmu_lock);
@@ -2709,9 +2716,7 @@ void gk20a_deinit_vm(struct vm_gk20a *vm)
         gk20a_allocator_destroy(&vm->vma[gmmu_page_size_big]);
         gk20a_allocator_destroy(&vm->vma[gmmu_page_size_small]);
 
-        unmap_gmmu_pages(&vm->pdb);
-        free_gmmu_pages(vm, &vm->pdb);
-        kfree(vm->pdb.entries);
+        gk20a_vm_free_entries(vm, &vm->pdb, 0);
 }
 
 int gk20a_alloc_inst_block(struct gk20a *g, struct mem_desc *inst_block)