gpu: host1x: drm: Add memory manager and fb

This patch introduces a memory manager for tegra drm and moves
existing parts to use it. As cma framebuffer helpers can no more
be used, this patch adds also a separate framebuffer driver for
tegra.

Signed-off-by: Arto Merilainen <amerilainen@nvidia.com>
Signed-off-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-by: Thierry Reding <thierry.reding@avionic-design.de>
Tested-by: Thierry Reding <thierry.reding@avionic-design.de>
Tested-by: Erik Faye-Lund <kusmabite@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
diff --git a/drivers/gpu/host1x/drm/gem.c b/drivers/gpu/host1x/drm/gem.c
new file mode 100644
index 0000000..c5e9a9b
--- /dev/null
+++ b/drivers/gpu/host1x/drm/gem.c
@@ -0,0 +1,270 @@
+/*
+ * NVIDIA Tegra DRM GEM helper functions
+ *
+ * Copyright (C) 2012 Sascha Hauer, Pengutronix
+ * Copyright (C) 2013 NVIDIA CORPORATION, All rights reserved.
+ *
+ * Based on the GEM/CMA helpers
+ *
+ * Copyright (c) 2011 Samsung Electronics Co., Ltd.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ * This program is distributed in the hope that 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.
+ */
+
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/mutex.h>
+#include <linux/export.h>
+#include <linux/dma-mapping.h>
+
+#include <drm/drmP.h>
+#include <drm/drm.h>
+
+#include "gem.h"
+
+static inline struct tegra_bo *host1x_to_drm_bo(struct host1x_bo *bo)
+{
+	return container_of(bo, struct tegra_bo, base);
+}
+
+static void tegra_bo_put(struct host1x_bo *bo)
+{
+	struct tegra_bo *obj = host1x_to_drm_bo(bo);
+	struct drm_device *drm = obj->gem.dev;
+
+	mutex_lock(&drm->struct_mutex);
+	drm_gem_object_unreference(&obj->gem);
+	mutex_unlock(&drm->struct_mutex);
+}
+
+static dma_addr_t tegra_bo_pin(struct host1x_bo *bo, struct sg_table **sgt)
+{
+	struct tegra_bo *obj = host1x_to_drm_bo(bo);
+
+	return obj->paddr;
+}
+
+static void tegra_bo_unpin(struct host1x_bo *bo, struct sg_table *sgt)
+{
+}
+
+static void *tegra_bo_mmap(struct host1x_bo *bo)
+{
+	struct tegra_bo *obj = host1x_to_drm_bo(bo);
+
+	return obj->vaddr;
+}
+
+static void tegra_bo_munmap(struct host1x_bo *bo, void *addr)
+{
+}
+
+static void *tegra_bo_kmap(struct host1x_bo *bo, unsigned int page)
+{
+	struct tegra_bo *obj = host1x_to_drm_bo(bo);
+
+	return obj->vaddr + page * PAGE_SIZE;
+}
+
+static void tegra_bo_kunmap(struct host1x_bo *bo, unsigned int page,
+			    void *addr)
+{
+}
+
+static struct host1x_bo *tegra_bo_get(struct host1x_bo *bo)
+{
+	struct tegra_bo *obj = host1x_to_drm_bo(bo);
+	struct drm_device *drm = obj->gem.dev;
+
+	mutex_lock(&drm->struct_mutex);
+	drm_gem_object_reference(&obj->gem);
+	mutex_unlock(&drm->struct_mutex);
+
+	return bo;
+}
+
+const struct host1x_bo_ops tegra_bo_ops = {
+	.get = tegra_bo_get,
+	.put = tegra_bo_put,
+	.pin = tegra_bo_pin,
+	.unpin = tegra_bo_unpin,
+	.mmap = tegra_bo_mmap,
+	.munmap = tegra_bo_munmap,
+	.kmap = tegra_bo_kmap,
+	.kunmap = tegra_bo_kunmap,
+};
+
+static void tegra_bo_destroy(struct drm_device *drm, struct tegra_bo *bo)
+{
+	dma_free_writecombine(drm->dev, bo->gem.size, bo->vaddr, bo->paddr);
+}
+
+unsigned int tegra_bo_get_mmap_offset(struct tegra_bo *bo)
+{
+	return (unsigned int)bo->gem.map_list.hash.key << PAGE_SHIFT;
+}
+
+struct tegra_bo *tegra_bo_create(struct drm_device *drm, unsigned int size)
+{
+	struct tegra_bo *bo;
+	int err;
+
+	bo = kzalloc(sizeof(*bo), GFP_KERNEL);
+	if (!bo)
+		return ERR_PTR(-ENOMEM);
+
+	host1x_bo_init(&bo->base, &tegra_bo_ops);
+	size = round_up(size, PAGE_SIZE);
+
+	bo->vaddr = dma_alloc_writecombine(drm->dev, size, &bo->paddr,
+					   GFP_KERNEL | __GFP_NOWARN);
+	if (!bo->vaddr) {
+		dev_err(drm->dev, "failed to allocate buffer with size %u\n",
+			size);
+		err = -ENOMEM;
+		goto err_dma;
+	}
+
+	err = drm_gem_object_init(drm, &bo->gem, size);
+	if (err)
+		goto err_init;
+
+	err = drm_gem_create_mmap_offset(&bo->gem);
+	if (err)
+		goto err_mmap;
+
+	return bo;
+
+err_mmap:
+	drm_gem_object_release(&bo->gem);
+err_init:
+	tegra_bo_destroy(drm, bo);
+err_dma:
+	kfree(bo);
+
+	return ERR_PTR(err);
+
+}
+
+struct tegra_bo *tegra_bo_create_with_handle(struct drm_file *file,
+					    struct drm_device *drm,
+					    unsigned int size,
+					    unsigned int *handle)
+{
+	struct tegra_bo *bo;
+	int ret;
+
+	bo = tegra_bo_create(drm, size);
+	if (IS_ERR(bo))
+		return bo;
+
+	ret = drm_gem_handle_create(file, &bo->gem, handle);
+	if (ret)
+		goto err;
+
+	drm_gem_object_unreference_unlocked(&bo->gem);
+
+	return bo;
+
+err:
+	tegra_bo_free_object(&bo->gem);
+	return ERR_PTR(ret);
+}
+
+void tegra_bo_free_object(struct drm_gem_object *gem)
+{
+	struct tegra_bo *bo = to_tegra_bo(gem);
+
+	if (gem->map_list.map)
+		drm_gem_free_mmap_offset(gem);
+
+	drm_gem_object_release(gem);
+	tegra_bo_destroy(gem->dev, bo);
+
+	kfree(bo);
+}
+
+int tegra_bo_dumb_create(struct drm_file *file, struct drm_device *drm,
+			 struct drm_mode_create_dumb *args)
+{
+	int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
+	struct tegra_bo *bo;
+
+	if (args->pitch < min_pitch)
+		args->pitch = min_pitch;
+
+	if (args->size < args->pitch * args->height)
+		args->size = args->pitch * args->height;
+
+	bo = tegra_bo_create_with_handle(file, drm, args->size,
+					    &args->handle);
+	if (IS_ERR(bo))
+		return PTR_ERR(bo);
+
+	return 0;
+}
+
+int tegra_bo_dumb_map_offset(struct drm_file *file, struct drm_device *drm,
+			     uint32_t handle, uint64_t *offset)
+{
+	struct drm_gem_object *gem;
+	struct tegra_bo *bo;
+
+	mutex_lock(&drm->struct_mutex);
+
+	gem = drm_gem_object_lookup(drm, file, handle);
+	if (!gem) {
+		dev_err(drm->dev, "failed to lookup GEM object\n");
+		mutex_unlock(&drm->struct_mutex);
+		return -EINVAL;
+	}
+
+	bo = to_tegra_bo(gem);
+
+	*offset = tegra_bo_get_mmap_offset(bo);
+
+	drm_gem_object_unreference(gem);
+
+	mutex_unlock(&drm->struct_mutex);
+
+	return 0;
+}
+
+const struct vm_operations_struct tegra_bo_vm_ops = {
+	.open = drm_gem_vm_open,
+	.close = drm_gem_vm_close,
+};
+
+int tegra_drm_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	struct drm_gem_object *gem;
+	struct tegra_bo *bo;
+	int ret;
+
+	ret = drm_gem_mmap(file, vma);
+	if (ret)
+		return ret;
+
+	gem = vma->vm_private_data;
+	bo = to_tegra_bo(gem);
+
+	ret = remap_pfn_range(vma, vma->vm_start, bo->paddr >> PAGE_SHIFT,
+			      vma->vm_end - vma->vm_start, vma->vm_page_prot);
+	if (ret)
+		drm_gem_vm_close(vma);
+
+	return ret;
+}
+
+int tegra_bo_dumb_destroy(struct drm_file *file, struct drm_device *drm,
+			  unsigned int handle)
+{
+	return drm_gem_handle_delete(file, handle);
+}