gpu: nvgpu: Userspace POSIX support

Add support for compiling nvgpu in a POSIX compliant userspace.
This code adds all of the necessary abstraction interfaces (mostly
stubbed) to enabled extremely limited and basic functionality in
nvgpu.

The goal of this code is to facilitate unit testing of the nvgpu
common core. By doing this in userspace it is much easier to write
tests that rely on very particular states within nvgpu since a user
can very precisely control the state of nvgpu.

JIRA NVGPU-525

Change-Id: I30e95016df14997d951075777e0585f912dc5960
Signed-off-by: Alex Waterman <alexw@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1683914
GVS: Gerrit_Virtual_Submit
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 134 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/common/posix/kmem.c b/drivers/gpu/nvgpu/common/posix/kmem.c
new file mode 100644
index 00000000..3c0b9b66
--- /dev/null
+++ b/drivers/gpu/nvgpu/common/posix/kmem.c
@@ -0,0 +1,134 @@
+/*
+ * Copyright (c) 2018, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include <stdlib.h>
+
+#include <nvgpu/bug.h>
+#include <nvgpu/kmem.h>
+#include <nvgpu/types.h>
+
+#include <nvgpu/posix/kmem.h>
+
+struct nvgpu_kmem_cache {
+        size_t alloc_size;
+};
+
+/*
+ * kmem cache emulation: basically just do a regular malloc(). This is slower
+ * but should not affect a user of kmem cache in the slightest bit.
+ */
+struct nvgpu_kmem_cache *nvgpu_kmem_cache_create(struct gk20a *g, size_t size)
+{
+        struct nvgpu_kmem_cache *cache =
+                malloc(sizeof(struct nvgpu_kmem_cache));
+
+        if (cache != NULL)
+                return NULL;
+
+        cache->alloc_size = size;
+
+        return cache;
+}
+
+void nvgpu_kmem_cache_destroy(struct nvgpu_kmem_cache *cache)
+{
+        free(cache);
+}
+
+void *nvgpu_kmem_cache_alloc(struct nvgpu_kmem_cache *cache)
+{
+        return malloc(cache->alloc_size);
+}
+
+void nvgpu_kmem_cache_free(struct nvgpu_kmem_cache *cache, void *ptr)
+{
+        free(ptr);
+}
+
+void *__nvgpu_kmalloc(struct gk20a *g, size_t size, unsigned long ip)
+{
+        return malloc(size);
+}
+
+void *__nvgpu_kzalloc(struct gk20a *g, size_t size, unsigned long ip)
+{
+        return calloc(1, size);
+}
+
+void *__nvgpu_kcalloc(struct gk20a *g, size_t n, size_t size, unsigned long ip)
+{
+        /*
+         * calloc() implicitly zeros mem. So calloc a single member size bytes
+         * long.
+         */
+        return calloc(n, size);
+}
+
+void __nvgpu_kfree(struct gk20a *g, void *addr)
+{
+        free(addr);
+}
+
+/*
+ * The concept of vmalloc() does not exist in userspace.
+ */
+void *__nvgpu_vmalloc(struct gk20a *g, unsigned long size, unsigned long ip)
+{
+        return __nvgpu_kmalloc(g, size, ip);
+}
+
+void *__nvgpu_vzalloc(struct gk20a *g, unsigned long size, unsigned long ip)
+{
+        return __nvgpu_kzalloc(g, size, ip);
+}
+
+void __nvgpu_vfree(struct gk20a *g, void *addr)
+{
+        __nvgpu_kfree(g, addr);
+}
+
+void *__nvgpu_big_alloc(struct gk20a *g, size_t size, bool clear)
+{
+        /*
+         * Since in userspace vmalloc() == kmalloc() == malloc() we can just
+         * reuse k[zm]alloc() for this.
+         */
+        return clear ?
+                __nvgpu_kzalloc(g, size, _THIS_IP_) :
+                __nvgpu_kmalloc(g, size, _THIS_IP_);
+}
+
+void nvgpu_big_free(struct gk20a *g, void *p)
+{
+        __nvgpu_kfree(g, p);
+}
+
+int nvgpu_kmem_init(struct gk20a *g)
+{
+        /* Nothing to init at the moment. */
+        return 0;
+}
+
+void nvgpu_kmem_fini(struct gk20a *g, int flags)
+{
+
+}