gpu: nvgpu: Separate vidmem alloc from Linux code

Split the core vidmem allocation from the Linux component of vidmem
allocation. The core vidmem allocation allocates the nvgpu_mem struct
that defines the vidmem buffer in the core MM code. The Linux code
now allocates some Linux specific stuff (dma_buf, etc) and also
allocates the core vidmem buf.

JIRA NVGPU-30
JIRA NVGPU-138

Change-Id: I88e87e0abd5ec714610eacc6eac17e148bcee3ce
Signed-off-by: Alex Waterman <alexw@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1540708
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

2 files changed, 102 insertions, 28 deletions

diff --git a/drivers/gpu/nvgpu/include/nvgpu/linux/vidmem.h b/drivers/gpu/nvgpu/include/nvgpu/linux/vidmem.h
new file mode 100644
index 00000000..76bbb05b
--- /dev/null
+++ b/drivers/gpu/nvgpu/include/nvgpu/linux/vidmem.h
@@ -0,0 +1,60 @@
+/*
+ * Copyright (c) 2017, 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,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __NVGPU_LINUX_VIDMEM_H__
+#define __NVGPU_LINUX_VIDMEM_H__
+
+#include <nvgpu/types.h>
+
+struct dma_buf;
+
+struct gk20a;
+
+#ifdef CONFIG_GK20A_VIDMEM
+struct gk20a *nvgpu_vidmem_buf_owner(struct dma_buf *dmabuf);
+int nvgpu_vidmem_export_linux(struct gk20a *g, size_t bytes);
+
+int nvgpu_vidmem_buf_access_memory(struct gk20a *g, struct dma_buf *dmabuf,
+                void *buffer, u64 offset, u64 size, u32 cmd);
+
+#else /* !CONFIG_GK20A_VIDMEM */
+static inline struct gk20a *nvgpu_vidmem_buf_owner(struct dma_buf *dmabuf)
+{
+        return NULL;
+}
+
+static inline int nvgpu_vidmem_export_linux(struct gk20a *g, size_t bytes)
+{
+        return -ENOSYS;
+}
+
+static inline int nvgpu_vidmem_buf_access_memory(struct gk20a *g,
+                                             struct dma_buf *dmabuf,
+                                             void *buffer, u64 offset,
+                                             u64 size, u32 cmd)
+{
+        return -ENOSYS;
+}
+
+#endif
+
+struct nvgpu_vidmem_linux {
+        struct dma_buf  *dmabuf;
+        void            *dmabuf_priv;
+        void            (*dmabuf_priv_delete)(void *);
+};
+
+#endif
diff --git a/drivers/gpu/nvgpu/include/nvgpu/vidmem.h b/drivers/gpu/nvgpu/include/nvgpu/vidmem.h
index 1b250f90..b89c710d 100644
--- a/drivers/gpu/nvgpu/include/nvgpu/vidmem.h
+++ b/drivers/gpu/nvgpu/include/nvgpu/vidmem.h
@@ -25,9 +25,9 @@
 
 #include <nvgpu/types.h>
 #include <nvgpu/errno.h>
+#include <nvgpu/nvgpu_mem.h>
 
 struct scatterlist;
-struct dma_buf;
 struct work_struct;
 
 struct gk20a;
@@ -35,37 +35,58 @@ struct mm_gk20a;
 struct nvgpu_mem;
 
 struct nvgpu_vidmem_buf {
-        struct gk20a *g;
-        struct nvgpu_mem *mem;
-        struct dma_buf *dmabuf;
-        void *dmabuf_priv;
-        void (*dmabuf_priv_delete)(void *);
+        /*
+         * Must be a pointer since control of this mem is passed over to the
+         * vidmem background clearing thread when the vidmem buf is freed.
+         */
+        struct nvgpu_mem        *mem;
+
+        struct gk20a            *g;
+
+        /*
+         * Filled in by each OS - this holds the necessary data to export this
+         * buffer to userspace. This will eventually be replaced by a struct
+         * which shall be defined in the OS specific vidmem.h header file.
+         */
+        void                    *priv;
 };
 
 #if defined(CONFIG_GK20A_VIDMEM)
 
+/**
+ * nvgpu_vidmem_user_alloc - Allocates a vidmem buffer for userspace
+ *
+ * @g     - The GPU.
+ * @bytes - Size of the buffer in bytes.
+ *
+ * Allocate a generic (OS agnostic) vidmem buffer. This does not allocate the OS
+ * specific interfacing for userspace sharing. Instead is is expected that the
+ * OS specific code will allocate that OS specific data and add it to this
+ * buffer.
+ *
+ * The buffer allocated here is intended to use used by userspace, hence the
+ * extra struct over nvgpu_mem. If a vidmem buffer is needed by the kernel
+ * driver only then a simple nvgpu_dma_alloc_vid() or the like is sufficient.
+ *
+ * Returns a pointer to a vidmem buffer on success, 0 otherwise.
+ */
+struct nvgpu_vidmem_buf *nvgpu_vidmem_user_alloc(struct gk20a *g, size_t bytes);
+
+void nvgpu_vidmem_buf_free(struct gk20a *g, struct nvgpu_vidmem_buf *buf);
+
 struct nvgpu_page_alloc *nvgpu_vidmem_get_page_alloc(struct scatterlist *sgl);
 void nvgpu_vidmem_set_page_alloc(struct scatterlist *sgl, u64 addr);
 bool nvgpu_addr_is_vidmem_page_alloc(u64 addr);
-int nvgpu_vidmem_buf_alloc(struct gk20a *g, size_t bytes);
 int nvgpu_vidmem_get_space(struct gk20a *g, u64 *space);
 
 struct nvgpu_mem *nvgpu_vidmem_get_pending_alloc(struct mm_gk20a *mm);
 
 void nvgpu_vidmem_destroy(struct gk20a *g);
 int nvgpu_vidmem_init(struct mm_gk20a *mm);
-int nvgpu_vidmem_clear_all(struct gk20a *g);
 
 void nvgpu_vidmem_clear_mem_worker(struct work_struct *work);
 int nvgpu_vidmem_clear(struct gk20a *g, struct nvgpu_mem *mem);
 
-/*
- * Will need to be moved later on once we have the Linux vidmem.h file.
- */
-struct gk20a *nvgpu_vidmem_buf_owner(struct dma_buf *dmabuf);
-int nvgpu_vidmem_buf_access_memory(struct gk20a *g, struct dma_buf *dmabuf,
-                void *buffer, u64 offset, u64 size, u32 cmd);
-
 #else /* !defined(CONFIG_GK20A_VIDMEM) */
 
 /*
@@ -91,6 +112,12 @@ static inline int nvgpu_vidmem_buf_alloc(struct gk20a *g, size_t bytes)
 {
         return -ENOSYS;
 }
+
+static inline void nvgpu_vidmem_buf_free(struct gk20a *g,
+                                         struct nvgpu_vidmem_buf *buf)
+{
+}
+
 static inline int nvgpu_vidmem_get_space(struct gk20a *g, u64 *space)
 {
         return -ENOSYS;
@@ -121,19 +148,6 @@ static inline int nvgpu_vidmem_clear(struct gk20a *g,
         return -ENOSYS;
 }
 
-static inline struct gk20a *nvgpu_vidmem_buf_owner(struct dma_buf *dmabuf)
-{
-        return NULL;
-}
-
-static inline int nvgpu_vidmem_buf_access_memory(struct gk20a *g,
-                                             struct dma_buf *dmabuf,
-                                             void *buffer, u64 offset,
-                                             u64 size, u32 cmd)
-{
-        return -ENOSYS;
-}
-
 #endif /* !defined(CONFIG_GK20A_VIDMEM) */
 
 #endif /* __NVGPU_VIDMEM_H__ */