cenalloc: simple test casecenalloc_wip

Add simple test case to cenalloc.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
 [benjiG: helped with making the test case work.]
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>

2 files changed, 170 insertions, 1 deletions

diff --git a/drivers/cenalloc/Makefile b/drivers/cenalloc/Makefile
index 2f69b61c0215..940d7c953a33 100644
--- a/drivers/cenalloc/Makefile
+++ b/drivers/cenalloc/Makefile
@@ -1,3 +1,3 @@
 # Makefile for the cenalloc helper
 
-obj-y				+= cenalloc.o cenalloc_system_contig.o
+obj-y			+= cenalloc.o cenalloc_system_contig.o cenalloc_test.o
diff --git a/drivers/cenalloc/cenalloc_test.c b/drivers/cenalloc/cenalloc_test.c
new file mode 100644
index 000000000000..6738965ca9ab
--- /dev/null
+++ b/drivers/cenalloc/cenalloc_test.c
@@ -0,0 +1,169 @@
+/*
+ * Simple Test code for constraint-aware allocation helper framework
+ * for devices using dma-buf
+ *
+ * drivers/cenalloc/cenalloc_test.c
+ *
+ * Copyright (C) 2014 Linaro, Inc
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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/err.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/bootmem.h>
+#include <linux/memblock.h>
+#include <linux/sizes.h>
+#include <linux/io.h>
+#include "cenalloc.h"
+#include "cenalloc_priv.h"
+
+static struct miscdevice dev1 = {
+		.minor = MISC_DYNAMIC_MINOR,
+		.name = "cenalloc-test1",
+		.parent = NULL,
+};
+
+static struct miscdevice dev2 = {
+		.minor = MISC_DYNAMIC_MINOR,
+		.name = "cenalloc-test2",
+		.parent = NULL,
+};
+
+static int __init cenalloc_test_init(void)
+{
+	int err;
+	struct dma_buf *dmabuf;
+	struct dma_buf_attachment *attach1, *attach2;
+	struct sg_table *table1, *table2;
+
+	err = misc_register(&dev1);
+	if (err) {
+		pr_err("cenalloc-test1: failed to register misc device.\n");
+		return err;
+	}
+	dev1.this_device->dma_parms = devm_kzalloc(dev1.this_device,
+					sizeof(*dev1.this_device->dma_parms),
+					GFP_KERNEL);
+
+	err = misc_register(&dev2);
+	if (err) {
+		pr_err("cenalloc-test2: failed to register misc device.\n");
+		return err;
+	}
+	dev2.this_device->dma_parms = devm_kzalloc(dev2.this_device,
+					sizeof(*dev2.this_device->dma_parms),
+					GFP_KERNEL);
+
+/* The following is the sequence to follow for dma-buf functions; this is
+ * for reference only; will add it in relevant sections in the test code.
+ *
+ * 1. create the dmabuf via cenalloc_buffer_create;*/
+	dmabuf = cenalloc_buffer_create(2048, 0, 0);
+
+	if (IS_ERR(dmabuf)) {
+		printk (KERN_ERR "create buffer failed\n");
+		return -EINVAL;
+	}
+
+ /* 2. set constraints for the attaching devices:*/
+	dev1.this_device->dma_parms->access_constraints_mask =
+					CENALLOC_ALLOCATOR_SYSTEM_MASK |
+					CENALLOC_ALLOCATOR_SYSTEM_CONTIG_MASK;
+
+	dev2.this_device->dma_parms->access_constraints_mask =
+					CENALLOC_ALLOCATOR_SYSTEM_MASK;
+
+/* 3. For each attaching device, call dma_buf_attach();
+ *    NOTE: Do remember that dma_buf_map_attachment() *MUST NOT* be called
+ *    before all attaching devices have attached themselves to the dmabuf.
+ *
+ *    Thanks to the constraints mask, each dma_buf_attach() call will check
+ *    against already attached devices, to see if the constraints are
+ *    compatible or not; if not, attach() would return an error.
+ *
+ *    Also, the dma_buf_fd() and dma_buf_get() would need to be called for
+ *    each buffer shared via userspace, before calling dma_buf_attach() on it.
+ */
+	attach1 = dma_buf_attach(dmabuf, dev1.this_device);
+	if (IS_ERR_OR_NULL(attach1)) {
+		pr_err("Couldn't attach device with constraint_mask: %0lx\n",
+			dev1.this_device->dma_parms->access_constraints_mask);
+		pr_err("Current constraint_mask for dma-buf: %0lx\n",
+				dmabuf->access_constraints_mask);
+		goto err1;
+	}
+
+	attach2 = dma_buf_attach(dmabuf, dev2.this_device);
+	if (IS_ERR_OR_NULL(attach2)) {
+		pr_err("Couldn't attach device with constraint_mask: %0lx\n",
+			dev2.this_device->dma_parms->access_constraints_mask);
+		pr_err("Current constraint_mask for dma-buf: %0lx\n",
+				dmabuf->access_constraints_mask);
+		goto err2;
+	}
+
+	pr_info(" Successfully Attached both devices \n");
+
+/* 4. Now, follow the dma_buf* operations sequence as desired; eg
+ *	NOTE: the very first call to dma_buf_map_attachment() will allocate
+ *	the backing storage, by finding the right allocator for the constraint;
+ *	subsequent calls would just return the associated sg_table.
+ */
+	table1 = dma_buf_map_attachment(attach1, DMA_BIDIRECTIONAL);
+	if (IS_ERR(table1)) {
+		pr_err("Couldn't map table1\n");
+		goto err3;
+	}
+/*	do something with the sg_table;*/
+
+	dma_buf_unmap_attachment(attach1, table1, DMA_BIDIRECTIONAL);
+
+
+	table2 = dma_buf_map_attachment(attach2, DMA_BIDIRECTIONAL);
+	if (IS_ERR(table2)) {
+		pr_err("Couldn't map table2\n");
+		goto err3;
+	}
+/*	do something with the sg_table;*/
+
+	dma_buf_unmap_attachment(attach2, table2, DMA_BIDIRECTIONAL);
+
+/* 5. If you're done with the use of the buffer; then for each importer, do
+ */
+err3:
+	dma_buf_detach(dmabuf, attach2);
+
+err2:
+	dma_buf_detach(dmabuf, attach1);
+err1:
+	dma_buf_put(dmabuf);
+
+	return 0;
+}
+
+
+device_initcall(cenalloc_test_init);
+
+static void __exit cenalloc_test_exit(void)
+{
+	misc_deregister(&dev1);
+	misc_deregister(&dev2);
+}
+__exitcall(cenalloc_test_exit);
+
+
+MODULE_AUTHOR("Sumit Semwal <sumit.semwal@linaro.org>");
+MODULE_DESCRIPTION("Constraint Aware Central Allocation Helper Test");
+MODULE_LICENSE("GPL");