video: tegra: nvmap: Don't expose non-embedded code in embedded builds

The following functions are exported from nvmap code and being used by
nvgpu in non-DriveOS code like L4T. Hence we should not include these
functions in embedded builds.
- nvmap_get_vpr_dev
- nvmap_get_vpr1_dev

The following functions get used in DriveOS as well by nvmap, but no
need to export to nvgpu, as they are not supposed to be used on DrivOS
by other modules. Hence do not export this in embedded builds.
- nvmap_dma_alloc_attrs
- nvmap_dma_free_attrs

In order to achieve this, define a new config file for embedded-linux
and define config and ccflag which can be used in any OOT driver to
differentiate between embedded-linux and non embedded-linux builds.

JIRA TMM-5842

Change-Id: Ic52106709723910e03362977472fb3597dc255f0
Signed-off-by: Ketan Patil <ketanp@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nv-oot/+/3258866
Reviewed-by: Laxman Dewangan <ldewangan@nvidia.com>
GVS: buildbot_gerritrpt <buildbot_gerritrpt@nvidia.com>

configs/Makefile.config.embedded-linux

@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0-only
+# SPDX-FileCopyrightText: Copyright (c) 2024 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+
+# Embedded linux specific environment variables to distinguish between embedded-linux and non embedded-linux builds.
+
+export NV_OOT_NVMAP_IN_EMBEDDED_LINUX=y
+subdir-ccflags-y += -DNV_CONFIG_NVMAP_IN_EMBEDDED_LINUX

drivers/video/tegra/nvmap/include/linux/nvmap_exports.h

@@ -5,9 +5,11 @@
 #ifndef __NVMAP_EXPORTS_H
 #define __NVMAP_EXPORTS_H
 
+#ifndef NV_CONFIG_NVMAP_IN_EMBEDDED_LINUX
 void *nvmap_dma_alloc_attrs(struct device *dev, size_t size,
 			    dma_addr_t *dma_handle, gfp_t flag,
 			    unsigned long attrs);
+
 void nvmap_dma_free_attrs(struct device *dev, size_t size, void *cpu_addr,
 			  dma_addr_t dma_handle, unsigned long attrs);
 
@@ -15,4 +17,5 @@ struct device *nvmap_get_vpr_dev(void);
 
 struct device *nvmap_get_vpr1_dev(void);
 
+#endif /* !NV_CONFIG_NVMAP_IN_EMBEDDED_LINUX */
 #endif /* __NVMAP_EXPORTS_H */

drivers/video/tegra/nvmap/nvmap_heap.c

@@ -476,9 +476,15 @@ err:
 	return NULL;
 }
 
+#ifndef NV_CONFIG_NVMAP_IN_EMBEDDED_LINUX
 void *nvmap_dma_alloc_attrs(struct device *dev, size_t size,
 			    dma_addr_t *dma_handle,
 			    gfp_t flag, unsigned long attrs)
+#else
+static void *nvmap_dma_alloc_attrs(struct device *dev, size_t size,
+			    dma_addr_t *dma_handle,
+			    gfp_t flag, unsigned long attrs)
+#endif /* NV_CONFIG_NVMAP_IN_EMBEDDED_LINUX */
 {
 	struct dma_coherent_mem_replica *mem;
 
@@ -492,7 +498,9 @@ void *nvmap_dma_alloc_attrs(struct device *dev, size_t size,
 	return __nvmap_dma_alloc_from_coherent(dev, mem, size, dma_handle,
 						   attrs, 0);
 }
+#ifndef NV_CONFIG_NVMAP_IN_EMBEDDED_LINUX
 EXPORT_SYMBOL(nvmap_dma_alloc_attrs);
+#endif /* !NV_CONFIG_NVMAP_IN_EMBEDDED_LINUX */
 
 #ifdef CONFIG_TEGRA_VIRTUALIZATION
 static void *nvmap_dma_mark_declared_memory_occupied(struct device *dev,
@@ -578,8 +586,13 @@ static phys_addr_t nvmap_alloc_mem(struct nvmap_heap *h, size_t len,
 	return pa;
 }
 
+#ifndef NV_CONFIG_NVMAP_IN_EMBEDDED_LINUX
 void nvmap_dma_free_attrs(struct device *dev, size_t size, void *cpu_addr,
 			  dma_addr_t dma_handle, unsigned long attrs)
+#else
+static void nvmap_dma_free_attrs(struct device *dev, size_t size, void *cpu_addr,
+			  dma_addr_t dma_handle, unsigned long attrs)
+#endif /* NV_CONFIG_NVMAP_IN_EMBEDDED_LINUX */
 {
 	void *mem_addr;
 	unsigned long flags;
@@ -629,7 +642,9 @@ void nvmap_dma_free_attrs(struct device *dev, size_t size, void *cpu_addr,
 		spin_unlock_irqrestore(&mem->spinlock, flags);
 	}
 }
+#ifndef NV_CONFIG_NVMAP_IN_EMBEDDED_LINUX
 EXPORT_SYMBOL(nvmap_dma_free_attrs);
+#endif /* !NV_CONFIG_NVMAP_IN_EMBEDDED_LINUX */
 
 static void nvmap_free_mem(struct nvmap_heap *h, phys_addr_t base,
 			   size_t len)

drivers/video/tegra/nvmap/nvmap_init.c

@@ -255,6 +255,7 @@ static int __nvmap_init_dt(struct platform_device *pdev)
 	return 0;
 }
 
+#ifndef NV_CONFIG_NVMAP_IN_EMBEDDED_LINUX
 struct device *nvmap_get_vpr_dev(void)
 {
 	struct device_node *dn = of_find_compatible_node(NULL, NULL, "nvidia,vpr-carveout");
@@ -288,6 +289,7 @@ struct device *nvmap_get_vpr1_dev(void)
 	return &tegra_vpr1_dev;
 }
 EXPORT_SYMBOL(nvmap_get_vpr1_dev);
+#endif /* !NV_CONFIG_NVMAP_IN_EMBEDDED_LINUX */
 
 static int __init nvmap_co_device_init(struct reserved_mem *rmem,
 					struct device *dev)