1 files changed, 241 insertions, 0 deletions
diff --git a/drivers/io/io_memmap.c b/drivers/io/io_memmap.c
new file mode 100644
index 0000000..fc06fbb
--- /dev/null
+++ b/drivers/io/io_memmap.c
@@ -0,0 +1,241 @@
+/*
+ * Copyright (c) 2014, ARM Limited and Contributors. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * Neither the name of ARM nor the names of its contributors may be used
+ * to endorse or promote products derived from this software without specific
+ * prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <assert.h>
+#include <debug.h>
+#include <io_driver.h>
+#include <io_storage.h>
+#include <string.h>
+
+/* As we need to be able to keep state for seek, only one file can be open
+ * at a time. Make this a structure and point to the entity->info. When we
+ * can malloc memory we can change this to support more open files.
+ */
+typedef struct {
+	/* Use the 'in_use' flag as any value for base and file_pos could be
+	 * valid.
+	 */
+	int		in_use;
+	uintptr_t	base;
+	size_t		file_pos;
+} file_state_t;
+
+static file_state_t current_file = {0};
+
+/* Identify the device type as memmap */
+io_type_t device_type_memmap(void)
+{
+	return IO_TYPE_MEMMAP;
+}
+
+/* Memmap device functions */
+static int memmap_dev_open(const uintptr_t dev_spec, io_dev_info_t **dev_info);
+static int memmap_block_open(io_dev_info_t *dev_info, const uintptr_t spec,
+			     io_entity_t *entity);
+static int memmap_block_seek(io_entity_t *entity, int mode,
+			     ssize_t offset);
+static int memmap_block_read(io_entity_t *entity, uintptr_t buffer,
+			     size_t length, size_t *length_read);
+static int memmap_block_write(io_entity_t *entity, const uintptr_t buffer,
+			      size_t length, size_t *length_written);
+static int memmap_block_close(io_entity_t *entity);
+static int memmap_dev_close(io_dev_info_t *dev_info);
+
+
+static const io_dev_connector_t memmap_dev_connector = {
+	.dev_open = memmap_dev_open
+};
+
+
+static const io_dev_funcs_t memmap_dev_funcs = {
+	.type = device_type_memmap,
+	.open = memmap_block_open,
+	.seek = memmap_block_seek,
+	.size = NULL,
+	.read = memmap_block_read,
+	.write = memmap_block_write,
+	.close = memmap_block_close,
+	.dev_init = NULL,
+	.dev_close = memmap_dev_close,
+};
+
+
+/* No state associated with this device so structure can be const */
+static const io_dev_info_t memmap_dev_info = {
+	.funcs = &memmap_dev_funcs,
+	.info = (uintptr_t)NULL
+};
+
+
+/* Open a connection to the memmap device */
+static int memmap_dev_open(const uintptr_t dev_spec __attribute__((unused)),
+			   io_dev_info_t **dev_info)
+{
+	assert(dev_info != NULL);
+	*dev_info = (io_dev_info_t *)&memmap_dev_info; /* cast away const */
+
+	return IO_SUCCESS;
+}
+
+
+
+/* Close a connection to the memmap device */
+static int memmap_dev_close(io_dev_info_t *dev_info)
+{
+	/* NOP */
+	/* TODO: Consider tracking open files and cleaning them up here */
+	return IO_SUCCESS;
+}
+
+
+/* Open a file on the memmap device */
+/* TODO: Can we do any sensible limit checks on requested memory */
+static int memmap_block_open(io_dev_info_t *dev_info, const uintptr_t spec,
+			     io_entity_t *entity)
+{
+	int result = IO_FAIL;
+	const io_block_spec_t *block_spec = (io_block_spec_t *)spec;
+
+	/* Since we need to track open state for seek() we only allow one open
+	 * spec at a time. When we have dynamic memory we can malloc and set
+	 * entity->info.
+	 */
+	if (current_file.in_use == 0) {
+		assert(block_spec != NULL);
+		assert(entity != NULL);
+
+		current_file.in_use = 1;
+		current_file.base = block_spec->offset;
+		/* File cursor offset for seek and incremental reads etc. */
+		current_file.file_pos = 0;
+		entity->info = (uintptr_t)&current_file;
+		result = IO_SUCCESS;
+	} else {
+		WARN("A Memmap device is already active. Close first.\n");
+		result = IO_RESOURCES_EXHAUSTED;
+	}
+
+	return result;
+}
+
+
+/* Seek to a particular file offset on the memmap device */
+static int memmap_block_seek(io_entity_t *entity, int mode, ssize_t offset)
+{
+	int result = IO_FAIL;
+
+	/* We only support IO_SEEK_SET for the moment. */
+	if (mode == IO_SEEK_SET) {
+		assert(entity != NULL);
+
+		/* TODO: can we do some basic limit checks on seek? */
+		((file_state_t *)entity->info)->file_pos = offset;
+		result = IO_SUCCESS;
+	} else {
+		result = IO_FAIL;
+	}
+
+	return result;
+}
+
+
+/* Read data from a file on the memmap device */
+static int memmap_block_read(io_entity_t *entity, uintptr_t buffer,
+			     size_t length, size_t *length_read)
+{
+	file_state_t *fp;
+
+	assert(entity != NULL);
+	assert(buffer != (uintptr_t)NULL);
+	assert(length_read != NULL);
+
+	fp = (file_state_t *)entity->info;
+
+	memcpy((void *)buffer, (void *)(fp->base + fp->file_pos), length);
+
+	*length_read = length;
+	/* advance the file 'cursor' for incremental reads */
+	fp->file_pos += length;
+
+	return IO_SUCCESS;
+}
+
+
+/* Write data to a file on the memmap device */
+static int memmap_block_write(io_entity_t *entity, const uintptr_t buffer,
+			      size_t length, size_t *length_written)
+{
+	file_state_t *fp;
+
+	assert(entity != NULL);
+	assert(buffer != (uintptr_t)NULL);
+	assert(length_written != NULL);
+
+	fp = (file_state_t *)entity->info;
+
+	memcpy((void *)(fp->base + fp->file_pos), (void *)buffer, length);
+
+	*length_written = length;
+
+	/* advance the file 'cursor' for incremental writes */
+	fp->file_pos += length;
+
+	return IO_SUCCESS;
+}
+
+
+/* Close a file on the memmap device */
+static int memmap_block_close(io_entity_t *entity)
+{
+	assert(entity != NULL);
+
+	entity->info = 0;
+
+	/* This would be a mem free() if we had malloc.*/
+	memset((void *)&current_file, 0, sizeof(current_file));
+
+	return IO_SUCCESS;
+}
+
+
+/* Exported functions */
+
+/* Register the memmap driver with the IO abstraction */
+int register_io_dev_memmap(const io_dev_connector_t **dev_con)
+{
+	int result = IO_FAIL;
+	assert(dev_con != NULL);
+
+	result = io_register_device(&memmap_dev_info);
+	if (result == IO_SUCCESS)
+		*dev_con = &memmap_dev_connector;
+
+	return result;
+}