3 files changed, 91 insertions, 15 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/cde_gk20a.c b/drivers/gpu/nvgpu/gk20a/cde_gk20a.c
index 57283343..49a1c1a8 100644
--- a/drivers/gpu/nvgpu/gk20a/cde_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/cde_gk20a.c
@@ -1,7 +1,7 @@
 /*
  * Color decompression engine support
  *
- * Copyright (c) 2014, NVIDIA Corporation.  All rights reserved.
+ * Copyright (c) 2014-2015, NVIDIA Corporation.  All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -979,17 +979,23 @@ __releases(&cde_app->mutex)
                 map_size = compbits_buf->size - map_offset;
         }
 
-        /* map the destination buffer */
-        get_dma_buf(compbits_buf); /* a ref for gk20a_vm_map */
-        map_vaddr = gk20a_vm_map(cde_ctx->vm, compbits_buf, 0,
-                                 NVGPU_MAP_BUFFER_FLAGS_CACHEABLE_TRUE,
-                                 compbits_kind, NULL, true,
-                                 gk20a_mem_flag_none,
-                                 map_offset, map_size);
+        /* map the destination buffer, if not cached yet */
+        /* races protected by the cde app mutex above */
+        map_vaddr = gk20a_vm_cde_mapped(cde_ctx->vm, compbits_buf);
         if (!map_vaddr) {
-                dma_buf_put(compbits_buf);
-                err = -EINVAL;
-                goto exit_unlock;
+                /* take a ref for gk20a_vm_map, pair is in (cached) unmap */
+                get_dma_buf(compbits_buf);
+                map_vaddr = gk20a_vm_map(cde_ctx->vm, compbits_buf, 0,
+                                NVGPU_MAP_BUFFER_FLAGS_CACHEABLE_TRUE,
+                                compbits_kind, NULL, true,
+                                gk20a_mem_flag_none,
+                                map_offset, map_size);
+                if (!map_vaddr) {
+                        dma_buf_put(compbits_buf);
+                        err = -EINVAL;
+                        goto exit_unlock;
+                }
+                gk20a_vm_mark_cde_mapped(cde_ctx->vm, compbits_buf, map_vaddr);
         }
 
         /* store source buffer compression tags */
@@ -1052,9 +1058,7 @@ __releases(&cde_app->mutex)
 
 exit_unlock:
 
-        /* unmap the buffers - channel holds references to them now */
-        if (map_vaddr)
-                gk20a_vm_unmap(cde_ctx->vm, map_vaddr);
+        /* leave map_vaddr mapped - released when unmapped from userspace */
 
         mutex_unlock(&g->cde_app.mutex);
         return err;
diff --git a/drivers/gpu/nvgpu/gk20a/mm_gk20a.c b/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
index d8bd3e70..79bfb687 100644
--- a/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/mm_gk20a.c
@@ -117,6 +117,11 @@ struct gk20a_dmabuf_priv {
         int pin_count;
 
         struct list_head states;
+
+        /* cached cde compbits buf */
+        struct vm_gk20a *cde_vm;
+        u64 cde_map_vaddr;
+        int map_count;
 };
 
 static void gk20a_vm_remove_support_nofree(struct vm_gk20a *vm);
@@ -198,6 +203,60 @@ void gk20a_mm_unpin(struct device *dev, struct dma_buf *dmabuf,
         mutex_unlock(&priv->lock);
 }
 
+/* CDE compbits buf caching: keep compbit buffer mapped during user mappings.
+ * Call these four only after dma_buf has a drvdata allocated */
+
+u64 gk20a_vm_cde_mapped(struct vm_gk20a *vm, struct dma_buf *dmabuf)
+{
+        struct device *dev = dev_from_vm(vm);
+        struct gk20a_dmabuf_priv *priv = dma_buf_get_drvdata(dmabuf, dev);
+        u64 map_vaddr;
+
+        mutex_lock(&priv->lock);
+        map_vaddr = priv->cde_map_vaddr;
+        mutex_unlock(&priv->lock);
+
+        return map_vaddr;
+}
+
+void gk20a_vm_mark_cde_mapped(struct vm_gk20a *vm, struct dma_buf *dmabuf,
+                u64 map_vaddr)
+{
+        struct device *dev = dev_from_vm(vm);
+        struct gk20a_dmabuf_priv *priv = dma_buf_get_drvdata(dmabuf, dev);
+
+        mutex_lock(&priv->lock);
+        priv->cde_vm = vm;
+        priv->cde_map_vaddr = map_vaddr;
+        mutex_unlock(&priv->lock);
+}
+
+static void gk20a_vm_inc_maps(struct vm_gk20a *vm, struct dma_buf *dmabuf)
+{
+        struct device *dev = dev_from_vm(vm);
+        struct gk20a_dmabuf_priv *priv = dma_buf_get_drvdata(dmabuf, dev);
+
+        mutex_lock(&priv->lock);
+        priv->map_count++;
+        mutex_unlock(&priv->lock);
+}
+
+static void gk20a_vm_dec_maps(struct vm_gk20a *vm, struct dma_buf *dmabuf,
+                struct vm_gk20a **cde_vm, u64 *cde_map_vaddr)
+{
+        struct device *dev = dev_from_vm(vm);
+        struct gk20a_dmabuf_priv *priv = dma_buf_get_drvdata(dmabuf, dev);
+
+        mutex_lock(&priv->lock);
+        if (--priv->map_count == 0) {
+                *cde_vm = priv->cde_vm;
+                *cde_map_vaddr = priv->cde_map_vaddr;
+                priv->cde_vm = NULL;
+                priv->cde_map_vaddr = 0;
+        }
+        mutex_unlock(&priv->lock);
+}
+
 void gk20a_get_comptags(struct device *dev, struct dma_buf *dmabuf,
                         struct gk20a_comptags *comptags)
 {
@@ -751,6 +810,8 @@ static void gk20a_vm_unmap_user(struct vm_gk20a *vm, u64 offset)
         struct device *d = dev_from_vm(vm);
         int retries;
         struct mapped_buffer_node *mapped_buffer;
+        struct vm_gk20a *cde_vm = NULL;
+        u64 cde_map_vaddr = 0;
 
         mutex_lock(&vm->update_gmmu_lock);
 
@@ -783,9 +844,15 @@ static void gk20a_vm_unmap_user(struct vm_gk20a *vm, u64 offset)
         mapped_buffer->user_mapped--;
         if (mapped_buffer->user_mapped == 0)
                 vm->num_user_mapped_buffers--;
+
+        gk20a_vm_dec_maps(vm, mapped_buffer->dmabuf, &cde_vm, &cde_map_vaddr);
+
         kref_put(&mapped_buffer->ref, gk20a_vm_unmap_locked_kref);
 
         mutex_unlock(&vm->update_gmmu_lock);
+
+        if (cde_map_vaddr)
+                gk20a_vm_unmap(cde_vm, cde_map_vaddr);
 }
 
 u64 gk20a_vm_alloc_va(struct vm_gk20a *vm,
@@ -2599,7 +2666,9 @@ int gk20a_vm_map_buffer(struct vm_gk20a *vm,
                         mapping_size);
 
         *offset_align = ret_va;
-        if (!ret_va) {
+        if (ret_va) {
+                gk20a_vm_inc_maps(vm, dmabuf);
+        } else {
                 dma_buf_put(dmabuf);
                 err = -EINVAL;
         }
diff --git a/drivers/gpu/nvgpu/gk20a/mm_gk20a.h b/drivers/gpu/nvgpu/gk20a/mm_gk20a.h
index 42c164be..8f0f736b 100644
--- a/drivers/gpu/nvgpu/gk20a/mm_gk20a.h
+++ b/drivers/gpu/nvgpu/gk20a/mm_gk20a.h
@@ -554,6 +554,9 @@ void gk20a_deinit_vm(struct vm_gk20a *vm);
 int gk20a_vm_unmap_buffer(struct vm_gk20a *vm, u64 offset);
 void gk20a_get_comptags(struct device *dev, struct dma_buf *dmabuf,
                         struct gk20a_comptags *comptags);
+u64 gk20a_vm_cde_mapped(struct vm_gk20a *vm, struct dma_buf *dmabuf);
+void gk20a_vm_mark_cde_mapped(struct vm_gk20a *vm, struct dma_buf *dmabuf,
+                u64 map_vaddr);
 dma_addr_t gk20a_mm_gpuva_to_iova_base(struct vm_gk20a *vm, u64 gpu_vaddr);
 
 int gk20a_dmabuf_alloc_drvdata(struct dma_buf *dmabuf, struct device *dev);