drivers/misc/cxl/flash.c - arm/linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 #include <linux/kernel.h>
 #include <linux/fs.h>
 #include <linux/semaphore.h>
 #include <linux/slab.h>
 #include <linux/uaccess.h>
 #include <asm/rtas.h>

 #include "cxl.h"
 #include "hcalls.h"

 #define DOWNLOAD_IMAGE 1
 #define VALIDATE_IMAGE 2

 struct ai_header {
 	u16 version;
 	u8  reserved0[6];
 	u16 vendor;
 	u16 device;
 	u16 subsystem_vendor;
 	u16 subsystem;
 	u64 image_offset;
 	u64 image_length;
 	u8  reserved1[96];
 };

 static struct semaphore sem;
 static unsigned long *buffer[CXL_AI_MAX_ENTRIES];
 static struct sg_list *le;
 static u64 continue_token;
 static unsigned int transfer;

 struct update_props_workarea {
 	__be32 phandle;
 	__be32 state;
 	__be64 reserved;
 	__be32 nprops;
 } __packed;

 struct update_nodes_workarea {
 	__be32 state;
 	__be64 unit_address;
 	__be32 reserved;
 } __packed;

 #define DEVICE_SCOPE 3
 #define NODE_ACTION_MASK	0xff000000
 #define NODE_COUNT_MASK		0x00ffffff
 #define OPCODE_DELETE	0x01000000
 #define OPCODE_UPDATE	0x02000000
 #define OPCODE_ADD	0x03000000

 static int rcall(int token, char *buf, s32 scope)
 {
 	int rc;

 	spin_lock(&rtas_data_buf_lock);

 	memcpy(rtas_data_buf, buf, RTAS_DATA_BUF_SIZE);
 	rc = rtas_call(token, 2, 1, NULL, rtas_data_buf, scope);
 	memcpy(buf, rtas_data_buf, RTAS_DATA_BUF_SIZE);

 	spin_unlock(&rtas_data_buf_lock);
 	return rc;
 }

 static int update_property(struct device_node *dn, const char *name,
 			   u32 vd, char *value)
 {
 	struct property *new_prop;
 	u32 *val;
 	int rc;

 	new_prop = kzalloc(sizeof(*new_prop), GFP_KERNEL);
 	if (!new_prop)
 		return -ENOMEM;

 	new_prop->name = kstrdup(name, GFP_KERNEL);
 	if (!new_prop->name) {
 		kfree(new_prop);
 		return -ENOMEM;
 	}

 	new_prop->length = vd;
 	new_prop->value = kzalloc(new_prop->length, GFP_KERNEL);
 	if (!new_prop->value) {
 		kfree(new_prop->name);
 		kfree(new_prop);
 		return -ENOMEM;
 	}
 	memcpy(new_prop->value, value, vd);

 	val = (u32 *)new_prop->value;
 	rc = cxl_update_properties(dn, new_prop);
 	pr_devel("%s: update property (%s, length: %i, value: %#x)\n",
 		  dn->name, name, vd, be32_to_cpu(*val));

 	if (rc) {
 		kfree(new_prop->name);
 		kfree(new_prop->value);
 		kfree(new_prop);
 	}
 	return rc;
 }

 static int update_node(__be32 phandle, s32 scope)
 {
 	struct update_props_workarea *upwa;
 	struct device_node *dn;
 	int i, rc, ret;
 	char *prop_data;
 	char *buf;
 	int token;
 	u32 nprops;
 	u32 vd;

 	token = rtas_token("ibm,update-properties");
 	if (token == RTAS_UNKNOWN_SERVICE)
 		return -EINVAL;

 	buf = kzalloc(RTAS_DATA_BUF_SIZE, GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;

 	dn = of_find_node_by_phandle(be32_to_cpu(phandle));
 	if (!dn) {
 		kfree(buf);
 		return -ENOENT;
 	}

 	upwa = (struct update_props_workarea *)&buf[0];
 	upwa->phandle = phandle;
 	do {
 		rc = rcall(token, buf, scope);
 		if (rc < 0)
 			break;

 		prop_data = buf + sizeof(*upwa);
 		nprops = be32_to_cpu(upwa->nprops);

 		if (*prop_data == 0) {
 			prop_data++;
 			vd = be32_to_cpu(*(__be32 *)prop_data);
 			prop_data += vd + sizeof(vd);
 			nprops--;
 		}

 		for (i = 0; i < nprops; i++) {
 			char *prop_name;

 			prop_name = prop_data;
 			prop_data += strlen(prop_name) + 1;
 			vd = be32_to_cpu(*(__be32 *)prop_data);
 			prop_data += sizeof(vd);

 			if ((vd != 0x00000000) && (vd != 0x80000000)) {
 				ret = update_property(dn, prop_name, vd,
 						prop_data);
 				if (ret)
 					pr_err("cxl: Could not update property %s - %i\n",
 					       prop_name, ret);

 				prop_data += vd;
 			}
 		}
 	} while (rc == 1);

 	of_node_put(dn);
 	kfree(buf);
 	return rc;
 }

 static int update_devicetree(struct cxl *adapter, s32 scope)
 {
 	struct update_nodes_workarea *unwa;
 	u32 action, node_count;
 	int token, rc, i;
 	__be32 *data, drc_index, phandle;
 	char *buf;

 	token = rtas_token("ibm,update-nodes");
 	if (token == RTAS_UNKNOWN_SERVICE)
 		return -EINVAL;

 	buf = kzalloc(RTAS_DATA_BUF_SIZE, GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;

 	unwa = (struct update_nodes_workarea *)&buf[0];
 	unwa->unit_address = cpu_to_be64(adapter->guest->handle);
 	do {
 		rc = rcall(token, buf, scope);
 		if (rc && rc != 1)
 			break;

 		data = (__be32 *)buf + 4;
 		while (be32_to_cpu(*data) & NODE_ACTION_MASK) {
 			action = be32_to_cpu(*data) & NODE_ACTION_MASK;
 			node_count = be32_to_cpu(*data) & NODE_COUNT_MASK;
 			pr_devel("device reconfiguration - action: %#x, nodes: %#x\n",
 				 action, node_count);
 			data++;

 			for (i = 0; i < node_count; i++) {
 				phandle = *data++;

 				switch (action) {
 				case OPCODE_DELETE:
 					/* nothing to do */
 					break;
 				case OPCODE_UPDATE:
 					update_node(phandle, scope);
 					break;
 				case OPCODE_ADD:
 					/* nothing to do, just move pointer */
 					drc_index = *data++;
 					break;
 				}
 			}
 		}
 	} while (rc == 1);

 	kfree(buf);
 	return 0;
 }

 static int handle_image(struct cxl *adapter, int operation,
 			long (*fct)(u64, u64, u64, u64 *),
 			struct cxl_adapter_image *ai)
 {
 	size_t mod, s_copy, len_chunk = 0;
 	struct ai_header *header = NULL;
 	unsigned int entries = 0, i;
 	void *dest, *from;
 	int rc = 0, need_header;

 	/* base adapter image header */
 	need_header = (ai->flags & CXL_AI_NEED_HEADER);
 	if (need_header) {
 		header = kzalloc(sizeof(struct ai_header), GFP_KERNEL);
 		if (!header)
 			return -ENOMEM;
 		header->version = cpu_to_be16(1);
 		header->vendor = cpu_to_be16(adapter->guest->vendor);
 		header->device = cpu_to_be16(adapter->guest->device);
 		header->subsystem_vendor = cpu_to_be16(adapter->guest->subsystem_vendor);
 		header->subsystem = cpu_to_be16(adapter->guest->subsystem);
 		header->image_offset = cpu_to_be64(CXL_AI_HEADER_SIZE);
 		header->image_length = cpu_to_be64(ai->len_image);
 	}

 	/* number of entries in the list */
 	len_chunk = ai->len_data;
 	if (need_header)
 		len_chunk += CXL_AI_HEADER_SIZE;

 	entries = len_chunk / CXL_AI_BUFFER_SIZE;
 	mod = len_chunk % CXL_AI_BUFFER_SIZE;
 	if (mod)
 		entries++;

 	if (entries > CXL_AI_MAX_ENTRIES) {
 		rc = -EINVAL;
 		goto err;
 	}

 	/*          < -- MAX_CHUNK_SIZE = 4096 * 256 = 1048576 bytes -->
 	 * chunk 0  ----------------------------------------------------
 	 *          | header   |  data                                 |
 	 *          ----------------------------------------------------
 	 * chunk 1  ----------------------------------------------------
 	 *          | data                                             |
 	 *          ----------------------------------------------------
 	 * ....
 	 * chunk n  ----------------------------------------------------
 	 *          | data                                             |
 	 *          ----------------------------------------------------
 	 */
 	from = (void *) ai->data;
 	for (i = 0; i < entries; i++) {
 		dest = buffer[i];
 		s_copy = CXL_AI_BUFFER_SIZE;

 		if ((need_header) && (i == 0)) {
 			/* add adapter image header */
 			memcpy(buffer[i], header, sizeof(struct ai_header));
 			s_copy = CXL_AI_BUFFER_SIZE - CXL_AI_HEADER_SIZE;
 			dest += CXL_AI_HEADER_SIZE; /* image offset */
 		}
 		if ((i == (entries - 1)) && mod)
 			s_copy = mod;

 		/* copy data */
 		if (copy_from_user(dest, from, s_copy))
 			goto err;

 		/* fill in the list */
 		le[i].phys_addr = cpu_to_be64(virt_to_phys(buffer[i]));
 		le[i].len = cpu_to_be64(CXL_AI_BUFFER_SIZE);
 		if ((i == (entries - 1)) && mod)
 			le[i].len = cpu_to_be64(mod);
 		from += s_copy;
 	}
 	pr_devel("%s (op: %i, need header: %i, entries: %i, token: %#llx)\n",
 		 __func__, operation, need_header, entries, continue_token);

 	/*
 	 * download/validate the adapter image to the coherent
 	 * platform facility
 	 */
 	rc = fct(adapter->guest->handle, virt_to_phys(le), entries,
 		&continue_token);
 	if (rc == 0) /* success of download/validation operation */
 		continue_token = 0;

 err:
 	kfree(header);

 	return rc;
 }

 static int transfer_image(struct cxl *adapter, int operation,
 			struct cxl_adapter_image *ai)
 {
 	int rc = 0;
 	int afu;

 	switch (operation) {
 	case DOWNLOAD_IMAGE:
 		rc = handle_image(adapter, operation,
 				&cxl_h_download_adapter_image, ai);
 		if (rc < 0) {
 			pr_devel("resetting adapter\n");
 			cxl_h_reset_adapter(adapter->guest->handle);
 		}
 		return rc;

 	case VALIDATE_IMAGE:
 		rc = handle_image(adapter, operation,
 				&cxl_h_validate_adapter_image, ai);
 		if (rc < 0) {
 			pr_devel("resetting adapter\n");
 			cxl_h_reset_adapter(adapter->guest->handle);
 			return rc;
 		}
 		if (rc == 0) {
 			pr_devel("remove current afu\n");
 			for (afu = 0; afu < adapter->slices; afu++)
 				cxl_guest_remove_afu(adapter->afu[afu]);

 			pr_devel("resetting adapter\n");
 			cxl_h_reset_adapter(adapter->guest->handle);

 			/* The entire image has now been
 			 * downloaded and the validation has
 			 * been successfully performed.
 			 * After that, the partition should call
 			 * ibm,update-nodes and
 			 * ibm,update-properties to receive the
 			 * current configuration
 			 */
 			rc = update_devicetree(adapter, DEVICE_SCOPE);
 			transfer = 1;
 		}
 		return rc;
 	}

 	return -EINVAL;
 }

 static long ioctl_transfer_image(struct cxl *adapter, int operation,
 				struct cxl_adapter_image __user *uai)
 {
 	struct cxl_adapter_image ai;

 	pr_devel("%s\n", __func__);

 	if (copy_from_user(&ai, uai, sizeof(struct cxl_adapter_image)))
 		return -EFAULT;

 	/*
 	 * Make sure reserved fields and bits are set to 0
 	 */
 	if (ai.reserved1 || ai.reserved2 || ai.reserved3 || ai.reserved4 ||
 		(ai.flags & ~CXL_AI_ALL))
 		return -EINVAL;

 	return transfer_image(adapter, operation, &ai);
 }

 static int device_open(struct inode *inode, struct file *file)
 {
 	int adapter_num = CXL_DEVT_ADAPTER(inode->i_rdev);
 	struct cxl *adapter;
 	int rc = 0, i;

 	pr_devel("in %s\n", __func__);

 	BUG_ON(sizeof(struct ai_header) != CXL_AI_HEADER_SIZE);

 	/* Allows one process to open the device by using a semaphore */
 	if (down_interruptible(&sem) != 0)
 		return -EPERM;

 	if (!(adapter = get_cxl_adapter(adapter_num))) {
 		rc = -ENODEV;
 		goto err_unlock;
 	}

 	file->private_data = adapter;
 	continue_token = 0;
 	transfer = 0;

 	for (i = 0; i < CXL_AI_MAX_ENTRIES; i++)
 		buffer[i] = NULL;

 	/* aligned buffer containing list entries which describes up to
 	 * 1 megabyte of data (256 entries of 4096 bytes each)
 	 *  Logical real address of buffer 0  -  Buffer 0 length in bytes
 	 *  Logical real address of buffer 1  -  Buffer 1 length in bytes
 	 *  Logical real address of buffer 2  -  Buffer 2 length in bytes
 	 *  ....
 	 *  ....
 	 *  Logical real address of buffer N  -  Buffer N length in bytes
 	 */
 	le = (struct sg_list *)get_zeroed_page(GFP_KERNEL);
 	if (!le) {
 		rc = -ENOMEM;
 		goto err;
 	}

 	for (i = 0; i < CXL_AI_MAX_ENTRIES; i++) {
 		buffer[i] = (unsigned long *)get_zeroed_page(GFP_KERNEL);
 		if (!buffer[i]) {
 			rc = -ENOMEM;
 			goto err1;
 		}
 	}

 	return 0;

 err1:
 	for (i = 0; i < CXL_AI_MAX_ENTRIES; i++) {
 		if (buffer[i])
 			free_page((unsigned long) buffer[i]);
 	}

 	if (le)
 		free_page((unsigned long) le);
 err:
 	put_device(&adapter->dev);
 err_unlock:
 	up(&sem);

 	return rc;
 }

 static long device_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
 	struct cxl *adapter = file->private_data;

 	pr_devel("in %s\n", __func__);

 	if (cmd == CXL_IOCTL_DOWNLOAD_IMAGE)
 		return ioctl_transfer_image(adapter,
 					DOWNLOAD_IMAGE,
 					(struct cxl_adapter_image __user *)arg);
 	else if (cmd == CXL_IOCTL_VALIDATE_IMAGE)
 		return ioctl_transfer_image(adapter,
 					VALIDATE_IMAGE,
 					(struct cxl_adapter_image __user *)arg);
 	else
 		return -EINVAL;
 }

 static long device_compat_ioctl(struct file *file, unsigned int cmd,
 				unsigned long arg)
 {
 	return device_ioctl(file, cmd, arg);
 }

 static int device_close(struct inode *inode, struct file *file)
 {
 	struct cxl *adapter = file->private_data;
 	int i;

 	pr_devel("in %s\n", __func__);

 	for (i = 0; i < CXL_AI_MAX_ENTRIES; i++) {
 		if (buffer[i])
 			free_page((unsigned long) buffer[i]);
 	}

 	if (le)
 		free_page((unsigned long) le);

 	up(&sem);
 	put_device(&adapter->dev);
 	continue_token = 0;

 	/* reload the module */
 	if (transfer)
 		cxl_guest_reload_module(adapter);
 	else {
 		pr_devel("resetting adapter\n");
 		cxl_h_reset_adapter(adapter->guest->handle);
 	}

 	transfer = 0;
 	return 0;
 }

 static const struct file_operations fops = {
 	.owner		= THIS_MODULE,
 	.open		= device_open,
 	.unlocked_ioctl	= device_ioctl,
 	.compat_ioctl	= device_compat_ioctl,
 	.release	= device_close,
 };

 void cxl_guest_remove_chardev(struct cxl *adapter)
 {
 	cdev_del(&adapter->guest->cdev);
 }

 int cxl_guest_add_chardev(struct cxl *adapter)
 {
 	dev_t devt;
 	int rc;

 	devt = MKDEV(MAJOR(cxl_get_dev()), CXL_CARD_MINOR(adapter));
 	cdev_init(&adapter->guest->cdev, &fops);
 	if ((rc = cdev_add(&adapter->guest->cdev, devt, 1))) {
 		dev_err(&adapter->dev,
 			"Unable to add chardev on adapter (card%i): %i\n",
 			adapter->adapter_num, rc);
 		goto err;
 	}
 	adapter->dev.devt = devt;
 	sema_init(&sem, 1);
 err:
 	return rc;
 }
	// SPDX-License-Identifier: GPL-2.0
	#include <linux/kernel.h>
	#include <linux/fs.h>
	#include <linux/semaphore.h>
	#include <linux/slab.h>
	#include <linux/uaccess.h>
	#include <asm/rtas.h>

	#include "cxl.h"
	#include "hcalls.h"

	#define DOWNLOAD_IMAGE 1
	#define VALIDATE_IMAGE 2

	struct ai_header {
	u16 version;
	u8 reserved0[6];
	u16 vendor;
	u16 device;
	u16 subsystem_vendor;
	u16 subsystem;
	u64 image_offset;
	u64 image_length;
	u8 reserved1[96];
	};

	static struct semaphore sem;
	static unsigned long *buffer[CXL_AI_MAX_ENTRIES];
	static struct sg_list *le;
	static u64 continue_token;
	static unsigned int transfer;

	struct update_props_workarea {
	__be32 phandle;
	__be32 state;
	__be64 reserved;
	__be32 nprops;
	} __packed;

	struct update_nodes_workarea {
	__be32 state;
	__be64 unit_address;
	__be32 reserved;
	} __packed;

	#define DEVICE_SCOPE 3
	#define NODE_ACTION_MASK 0xff000000
	#define NODE_COUNT_MASK 0x00ffffff
	#define OPCODE_DELETE 0x01000000
	#define OPCODE_UPDATE 0x02000000
	#define OPCODE_ADD 0x03000000

	static int rcall(int token, char *buf, s32 scope)
	{
	int rc;

	spin_lock(&rtas_data_buf_lock);

	memcpy(rtas_data_buf, buf, RTAS_DATA_BUF_SIZE);
	rc = rtas_call(token, 2, 1, NULL, rtas_data_buf, scope);
	memcpy(buf, rtas_data_buf, RTAS_DATA_BUF_SIZE);

	spin_unlock(&rtas_data_buf_lock);
	return rc;
	}

	static int update_property(struct device_node dn, const char name,
	u32 vd, char *value)
	{
	struct property *new_prop;
	u32 *val;
	int rc;

	new_prop = kzalloc(sizeof(*new_prop), GFP_KERNEL);
	if (!new_prop)
	return -ENOMEM;

	new_prop->name = kstrdup(name, GFP_KERNEL);
	if (!new_prop->name) {
	kfree(new_prop);
	return -ENOMEM;
	}

	new_prop->length = vd;
	new_prop->value = kzalloc(new_prop->length, GFP_KERNEL);
	if (!new_prop->value) {
	kfree(new_prop->name);
	kfree(new_prop);
	return -ENOMEM;
	}
	memcpy(new_prop->value, value, vd);

	val = (u32 *)new_prop->value;
	rc = cxl_update_properties(dn, new_prop);
	pr_devel("%s: update property (%s, length: %i, value: %#x)\n",
	dn->name, name, vd, be32_to_cpu(*val));

	if (rc) {
	kfree(new_prop->name);
	kfree(new_prop->value);
	kfree(new_prop);
	}
	return rc;
	}

	static int update_node(__be32 phandle, s32 scope)
	{
	struct update_props_workarea *upwa;
	struct device_node *dn;
	int i, rc, ret;
	char *prop_data;
	char *buf;
	int token;
	u32 nprops;
	u32 vd;

	token = rtas_token("ibm,update-properties");
	if (token == RTAS_UNKNOWN_SERVICE)
	return -EINVAL;

	buf = kzalloc(RTAS_DATA_BUF_SIZE, GFP_KERNEL);
	if (!buf)
	return -ENOMEM;

	dn = of_find_node_by_phandle(be32_to_cpu(phandle));
	if (!dn) {
	kfree(buf);
	return -ENOENT;
	}

	upwa = (struct update_props_workarea *)&buf[0];
	upwa->phandle = phandle;
	do {
	rc = rcall(token, buf, scope);
	if (rc < 0)
	break;

	prop_data = buf + sizeof(*upwa);
	nprops = be32_to_cpu(upwa->nprops);

	if (*prop_data == 0) {
	prop_data++;
	vd = be32_to_cpu((__be32 )prop_data);
	prop_data += vd + sizeof(vd);
	nprops--;
	}

	for (i = 0; i < nprops; i++) {
	char *prop_name;

	prop_name = prop_data;
	prop_data += strlen(prop_name) + 1;
	vd = be32_to_cpu((__be32 )prop_data);
	prop_data += sizeof(vd);

	if ((vd != 0x00000000) && (vd != 0x80000000)) {
	ret = update_property(dn, prop_name, vd,
	prop_data);
	if (ret)
	pr_err("cxl: Could not update property %s - %i\n",
	prop_name, ret);

	prop_data += vd;
	}
	}
	} while (rc == 1);

	of_node_put(dn);
	kfree(buf);
	return rc;
	}

	static int update_devicetree(struct cxl *adapter, s32 scope)
	{
	struct update_nodes_workarea *unwa;
	u32 action, node_count;
	int token, rc, i;
	__be32 *data, drc_index, phandle;
	char *buf;

	token = rtas_token("ibm,update-nodes");
	if (token == RTAS_UNKNOWN_SERVICE)
	return -EINVAL;

	buf = kzalloc(RTAS_DATA_BUF_SIZE, GFP_KERNEL);
	if (!buf)
	return -ENOMEM;

	unwa = (struct update_nodes_workarea *)&buf[0];
	unwa->unit_address = cpu_to_be64(adapter->guest->handle);
	do {
	rc = rcall(token, buf, scope);
	if (rc && rc != 1)
	break;

	data = (__be32 *)buf + 4;
	while (be32_to_cpu(*data) & NODE_ACTION_MASK) {
	action = be32_to_cpu(*data) & NODE_ACTION_MASK;
	node_count = be32_to_cpu(*data) & NODE_COUNT_MASK;
	pr_devel("device reconfiguration - action: %#x, nodes: %#x\n",
	action, node_count);
	data++;

	for (i = 0; i < node_count; i++) {
	phandle = *data++;

	switch (action) {
	case OPCODE_DELETE:
	/* nothing to do */
	break;
	case OPCODE_UPDATE:
	update_node(phandle, scope);
	break;
	case OPCODE_ADD:
	/* nothing to do, just move pointer */
	drc_index = *data++;
	break;
	}
	}
	}
	} while (rc == 1);

	kfree(buf);
	return 0;
	}

	static int handle_image(struct cxl *adapter, int operation,
	long (fct)(u64, u64, u64, u64 ),
	struct cxl_adapter_image *ai)
	{
	size_t mod, s_copy, len_chunk = 0;
	struct ai_header *header = NULL;
	unsigned int entries = 0, i;
	void dest, from;
	int rc = 0, need_header;

	/* base adapter image header */
	need_header = (ai->flags & CXL_AI_NEED_HEADER);
	if (need_header) {
	header = kzalloc(sizeof(struct ai_header), GFP_KERNEL);
	if (!header)
	return -ENOMEM;
	header->version = cpu_to_be16(1);
	header->vendor = cpu_to_be16(adapter->guest->vendor);
	header->device = cpu_to_be16(adapter->guest->device);
	header->subsystem_vendor = cpu_to_be16(adapter->guest->subsystem_vendor);
	header->subsystem = cpu_to_be16(adapter->guest->subsystem);
	header->image_offset = cpu_to_be64(CXL_AI_HEADER_SIZE);
	header->image_length = cpu_to_be64(ai->len_image);
	}

	/* number of entries in the list */
	len_chunk = ai->len_data;
	if (need_header)
	len_chunk += CXL_AI_HEADER_SIZE;

	entries = len_chunk / CXL_AI_BUFFER_SIZE;
	mod = len_chunk % CXL_AI_BUFFER_SIZE;
	if (mod)
	entries++;

	if (entries > CXL_AI_MAX_ENTRIES) {
	rc = -EINVAL;
	goto err;
	}

	/* < -- MAX_CHUNK_SIZE = 4096 * 256 = 1048576 bytes -->
	* chunk 0 ----------------------------------------------------
	* \| header \| data \|
	* ----------------------------------------------------
	* chunk 1 ----------------------------------------------------
	* \| data \|
	* ----------------------------------------------------
	* ....
	* chunk n ----------------------------------------------------
	* \| data \|
	* ----------------------------------------------------
	*/
	from = (void *) ai->data;
	for (i = 0; i < entries; i++) {
	dest = buffer[i];
	s_copy = CXL_AI_BUFFER_SIZE;

	if ((need_header) && (i == 0)) {
	/* add adapter image header */
	memcpy(buffer[i], header, sizeof(struct ai_header));
	s_copy = CXL_AI_BUFFER_SIZE - CXL_AI_HEADER_SIZE;
	dest += CXL_AI_HEADER_SIZE; /* image offset */
	}
	if ((i == (entries - 1)) && mod)
	s_copy = mod;

	/* copy data */
	if (copy_from_user(dest, from, s_copy))
	goto err;

	/* fill in the list */
	le[i].phys_addr = cpu_to_be64(virt_to_phys(buffer[i]));
	le[i].len = cpu_to_be64(CXL_AI_BUFFER_SIZE);
	if ((i == (entries - 1)) && mod)
	le[i].len = cpu_to_be64(mod);
	from += s_copy;
	}
	pr_devel("%s (op: %i, need header: %i, entries: %i, token: %#llx)\n",
	__func__, operation, need_header, entries, continue_token);

	/*
	* download/validate the adapter image to the coherent
	* platform facility
	*/
	rc = fct(adapter->guest->handle, virt_to_phys(le), entries,
	&continue_token);
	if (rc == 0) /* success of download/validation operation */
	continue_token = 0;

	err:
	kfree(header);

	return rc;
	}

	static int transfer_image(struct cxl *adapter, int operation,
	struct cxl_adapter_image *ai)
	{
	int rc = 0;
	int afu;

	switch (operation) {
	case DOWNLOAD_IMAGE:
	rc = handle_image(adapter, operation,
	&cxl_h_download_adapter_image, ai);
	if (rc < 0) {
	pr_devel("resetting adapter\n");
	cxl_h_reset_adapter(adapter->guest->handle);
	}
	return rc;

	case VALIDATE_IMAGE:
	rc = handle_image(adapter, operation,
	&cxl_h_validate_adapter_image, ai);
	if (rc < 0) {
	pr_devel("resetting adapter\n");
	cxl_h_reset_adapter(adapter->guest->handle);
	return rc;
	}
	if (rc == 0) {
	pr_devel("remove current afu\n");
	for (afu = 0; afu < adapter->slices; afu++)
	cxl_guest_remove_afu(adapter->afu[afu]);

	pr_devel("resetting adapter\n");
	cxl_h_reset_adapter(adapter->guest->handle);

	/* The entire image has now been
	* downloaded and the validation has
	* been successfully performed.
	* After that, the partition should call
	* ibm,update-nodes and
	* ibm,update-properties to receive the
	* current configuration
	*/
	rc = update_devicetree(adapter, DEVICE_SCOPE);
	transfer = 1;
	}
	return rc;
	}

	return -EINVAL;
	}

	static long ioctl_transfer_image(struct cxl *adapter, int operation,
	struct cxl_adapter_image __user *uai)
	{
	struct cxl_adapter_image ai;

	pr_devel("%s\n", __func__);

	if (copy_from_user(&ai, uai, sizeof(struct cxl_adapter_image)))
	return -EFAULT;

	/*
	* Make sure reserved fields and bits are set to 0
	*/
	if (ai.reserved1 \|\| ai.reserved2 \|\| ai.reserved3 \|\| ai.reserved4 \|\|
	(ai.flags & ~CXL_AI_ALL))
	return -EINVAL;

	return transfer_image(adapter, operation, &ai);
	}

	static int device_open(struct inode inode, struct file file)
	{
	int adapter_num = CXL_DEVT_ADAPTER(inode->i_rdev);
	struct cxl *adapter;
	int rc = 0, i;

	pr_devel("in %s\n", __func__);

	BUG_ON(sizeof(struct ai_header) != CXL_AI_HEADER_SIZE);

	/* Allows one process to open the device by using a semaphore */
	if (down_interruptible(&sem) != 0)
	return -EPERM;

	if (!(adapter = get_cxl_adapter(adapter_num))) {
	rc = -ENODEV;
	goto err_unlock;
	}

	file->private_data = adapter;
	continue_token = 0;
	transfer = 0;

	for (i = 0; i < CXL_AI_MAX_ENTRIES; i++)
	buffer[i] = NULL;

	/* aligned buffer containing list entries which describes up to
	* 1 megabyte of data (256 entries of 4096 bytes each)
	* Logical real address of buffer 0 - Buffer 0 length in bytes
	* Logical real address of buffer 1 - Buffer 1 length in bytes
	* Logical real address of buffer 2 - Buffer 2 length in bytes
	* ....
	* ....
	* Logical real address of buffer N - Buffer N length in bytes
	*/
	le = (struct sg_list *)get_zeroed_page(GFP_KERNEL);
	if (!le) {
	rc = -ENOMEM;
	goto err;
	}

	for (i = 0; i < CXL_AI_MAX_ENTRIES; i++) {
	buffer[i] = (unsigned long *)get_zeroed_page(GFP_KERNEL);
	if (!buffer[i]) {
	rc = -ENOMEM;
	goto err1;
	}
	}

	return 0;

	err1:
	for (i = 0; i < CXL_AI_MAX_ENTRIES; i++) {
	if (buffer[i])
	free_page((unsigned long) buffer[i]);
	}

	if (le)
	free_page((unsigned long) le);
	err:
	put_device(&adapter->dev);
	err_unlock:
	up(&sem);

	return rc;
	}

	static long device_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
	{
	struct cxl *adapter = file->private_data;

	pr_devel("in %s\n", __func__);

	if (cmd == CXL_IOCTL_DOWNLOAD_IMAGE)
	return ioctl_transfer_image(adapter,
	DOWNLOAD_IMAGE,
	(struct cxl_adapter_image __user *)arg);
	else if (cmd == CXL_IOCTL_VALIDATE_IMAGE)
	return ioctl_transfer_image(adapter,
	VALIDATE_IMAGE,
	(struct cxl_adapter_image __user *)arg);
	else
	return -EINVAL;
	}

	static long device_compat_ioctl(struct file *file, unsigned int cmd,
	unsigned long arg)
	{
	return device_ioctl(file, cmd, arg);
	}

	static int device_close(struct inode inode, struct file file)
	{
	struct cxl *adapter = file->private_data;
	int i;

	pr_devel("in %s\n", __func__);

	for (i = 0; i < CXL_AI_MAX_ENTRIES; i++) {
	if (buffer[i])
	free_page((unsigned long) buffer[i]);
	}

	if (le)
	free_page((unsigned long) le);

	up(&sem);
	put_device(&adapter->dev);
	continue_token = 0;

	/* reload the module */
	if (transfer)
	cxl_guest_reload_module(adapter);
	else {
	pr_devel("resetting adapter\n");
	cxl_h_reset_adapter(adapter->guest->handle);
	}

	transfer = 0;
	return 0;
	}

	static const struct file_operations fops = {
	.owner = THIS_MODULE,
	.open = device_open,
	.unlocked_ioctl = device_ioctl,
	.compat_ioctl = device_compat_ioctl,
	.release = device_close,
	};

	void cxl_guest_remove_chardev(struct cxl *adapter)
	{
	cdev_del(&adapter->guest->cdev);
	}

	int cxl_guest_add_chardev(struct cxl *adapter)
	{
	dev_t devt;
	int rc;

	devt = MKDEV(MAJOR(cxl_get_dev()), CXL_CARD_MINOR(adapter));
	cdev_init(&adapter->guest->cdev, &fops);
	if ((rc = cdev_add(&adapter->guest->cdev, devt, 1))) {
	dev_err(&adapter->dev,
	"Unable to add chardev on adapter (card%i): %i\n",
	adapter->adapter_num, rc);
	goto err;
	}
	adapter->dev.devt = devt;
	sema_init(&sem, 1);
	err:
	return rc;
	}