1 files changed, 680 insertions, 0 deletions

diff --git a/drivers/platform/x86/dell_rbu.c b/drivers/platform/x86/dell_rbu.c
new file mode 100644
index 000000000..03c3ff34b
--- /dev/null
+++ b/drivers/platform/x86/dell_rbu.c
@@ -0,0 +1,680 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * dell_rbu.c
+ * Bios Update driver for Dell systems
+ * Author: Dell Inc
+ *         Abhay Salunke <abhay_salunke@dell.com>
+ *
+ * Copyright (C) 2005 Dell Inc.
+ *
+ * Remote BIOS Update (rbu) driver is used for updating DELL BIOS by
+ * creating entries in the /sys file systems on Linux 2.6 and higher
+ * kernels. The driver supports two mechanism to update the BIOS namely
+ * contiguous and packetized. Both these methods still require having some
+ * application to set the CMOS bit indicating the BIOS to update itself
+ * after a reboot.
+ *
+ * Contiguous method:
+ * This driver writes the incoming data in a monolithic image by allocating
+ * contiguous physical pages large enough to accommodate the incoming BIOS
+ * image size.
+ *
+ * Packetized method:
+ * The driver writes the incoming packet image by allocating a new packet
+ * on every time the packet data is written. This driver requires an
+ * application to break the BIOS image in to fixed sized packet chunks.
+ *
+ * See Documentation/admin-guide/dell_rbu.rst for more info.
+ */
+
+#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/blkdev.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+#include <linux/moduleparam.h>
+#include <linux/firmware.h>
+#include <linux/dma-mapping.h>
+#include <asm/set_memory.h>
+
+MODULE_AUTHOR("Abhay Salunke <abhay_salunke@dell.com>");
+MODULE_DESCRIPTION("Driver for updating BIOS image on DELL systems");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("3.2");
+
+#define BIOS_SCAN_LIMIT 0xffffffff
+#define MAX_IMAGE_LENGTH 16
+static struct _rbu_data {
+	void *image_update_buffer;
+	unsigned long image_update_buffer_size;
+	unsigned long bios_image_size;
+	int image_update_ordernum;
+	spinlock_t lock;
+	unsigned long packet_read_count;
+	unsigned long num_packets;
+	unsigned long packetsize;
+	unsigned long imagesize;
+	int entry_created;
+} rbu_data;
+
+static char image_type[MAX_IMAGE_LENGTH + 1] = "mono";
+module_param_string(image_type, image_type, sizeof (image_type), 0);
+MODULE_PARM_DESC(image_type, "BIOS image type. choose- mono or packet or init");
+
+static unsigned long allocation_floor = 0x100000;
+module_param(allocation_floor, ulong, 0644);
+MODULE_PARM_DESC(allocation_floor, "Minimum address for allocations when using Packet mode");
+
+struct packet_data {
+	struct list_head list;
+	size_t length;
+	void *data;
+	int ordernum;
+};
+
+static struct packet_data packet_data_head;
+
+static struct platform_device *rbu_device;
+static int context;
+
+static void init_packet_head(void)
+{
+	INIT_LIST_HEAD(&packet_data_head.list);
+	rbu_data.packet_read_count = 0;
+	rbu_data.num_packets = 0;
+	rbu_data.packetsize = 0;
+	rbu_data.imagesize = 0;
+}
+
+static int create_packet(void *data, size_t length)
+{
+	struct packet_data *newpacket;
+	int ordernum = 0;
+	int retval = 0;
+	unsigned int packet_array_size = 0;
+	void **invalid_addr_packet_array = NULL;
+	void *packet_data_temp_buf = NULL;
+	unsigned int idx = 0;
+
+	pr_debug("entry\n");
+
+	if (!rbu_data.packetsize) {
+		pr_debug("packetsize not specified\n");
+		retval = -EINVAL;
+		goto out_noalloc;
+	}
+
+	spin_unlock(&rbu_data.lock);
+
+	newpacket = kzalloc(sizeof (struct packet_data), GFP_KERNEL);
+
+	if (!newpacket) {
+		pr_warn("failed to allocate new packet\n");
+		retval = -ENOMEM;
+		spin_lock(&rbu_data.lock);
+		goto out_noalloc;
+	}
+
+	ordernum = get_order(length);
+
+	/*
+	 * BIOS errata mean we cannot allocate packets below 1MB or they will
+	 * be overwritten by BIOS.
+	 *
+	 * array to temporarily hold packets
+	 * that are below the allocation floor
+	 *
+	 * NOTE: very simplistic because we only need the floor to be at 1MB
+	 *       due to BIOS errata. This shouldn't be used for higher floors
+	 *       or you will run out of mem trying to allocate the array.
+	 */
+	packet_array_size = max_t(unsigned int, allocation_floor / rbu_data.packetsize, 1);
+	invalid_addr_packet_array = kcalloc(packet_array_size, sizeof(void *),
+						GFP_KERNEL);
+
+	if (!invalid_addr_packet_array) {
+		pr_warn("failed to allocate invalid_addr_packet_array\n");
+		retval = -ENOMEM;
+		spin_lock(&rbu_data.lock);
+		goto out_alloc_packet;
+	}
+
+	while (!packet_data_temp_buf) {
+		packet_data_temp_buf = (unsigned char *)
+			__get_free_pages(GFP_KERNEL, ordernum);
+		if (!packet_data_temp_buf) {
+			pr_warn("failed to allocate new packet\n");
+			retval = -ENOMEM;
+			spin_lock(&rbu_data.lock);
+			goto out_alloc_packet_array;
+		}
+
+		if ((unsigned long)virt_to_phys(packet_data_temp_buf)
+				< allocation_floor) {
+			pr_debug("packet 0x%lx below floor at 0x%lx\n",
+					(unsigned long)virt_to_phys(
+						packet_data_temp_buf),
+					allocation_floor);
+			invalid_addr_packet_array[idx++] = packet_data_temp_buf;
+			packet_data_temp_buf = NULL;
+		}
+	}
+	/*
+	 * set to uncachable or it may never get written back before reboot
+	 */
+	set_memory_uc((unsigned long)packet_data_temp_buf, 1 << ordernum);
+
+	spin_lock(&rbu_data.lock);
+
+	newpacket->data = packet_data_temp_buf;
+
+	pr_debug("newpacket at physical addr %lx\n",
+		(unsigned long)virt_to_phys(newpacket->data));
+
+	/* packets may not have fixed size */
+	newpacket->length = length;
+	newpacket->ordernum = ordernum;
+	++rbu_data.num_packets;
+
+	/* initialize the newly created packet headers */
+	INIT_LIST_HEAD(&newpacket->list);
+	list_add_tail(&newpacket->list, &packet_data_head.list);
+
+	memcpy(newpacket->data, data, length);
+
+	pr_debug("exit\n");
+
+out_alloc_packet_array:
+	/* always free packet array */
+	while (idx--) {
+		pr_debug("freeing unused packet below floor 0x%lx\n",
+			(unsigned long)virt_to_phys(invalid_addr_packet_array[idx]));
+		free_pages((unsigned long)invalid_addr_packet_array[idx], ordernum);
+	}
+	kfree(invalid_addr_packet_array);
+
+out_alloc_packet:
+	/* if error, free data */
+	if (retval)
+		kfree(newpacket);
+
+out_noalloc:
+	return retval;
+}
+
+static int packetize_data(const u8 *data, size_t length)
+{
+	int rc = 0;
+	int done = 0;
+	int packet_length;
+	u8 *temp;
+	u8 *end = (u8 *) data + length;
+	pr_debug("data length %zd\n", length);
+	if (!rbu_data.packetsize) {
+		pr_warn("packetsize not specified\n");
+		return -EIO;
+	}
+
+	temp = (u8 *) data;
+
+	/* packetize the hunk */
+	while (!done) {
+		if ((temp + rbu_data.packetsize) < end)
+			packet_length = rbu_data.packetsize;
+		else {
+			/* this is the last packet */
+			packet_length = end - temp;
+			done = 1;
+		}
+
+		if ((rc = create_packet(temp, packet_length)))
+			return rc;
+
+		pr_debug("%p:%td\n", temp, (end - temp));
+		temp += packet_length;
+	}
+
+	rbu_data.imagesize = length;
+
+	return rc;
+}
+
+static int do_packet_read(char *data, struct packet_data *newpacket,
+	int length, int bytes_read, int *list_read_count)
+{
+	void *ptemp_buf;
+	int bytes_copied = 0;
+	int j = 0;
+
+	*list_read_count += newpacket->length;
+
+	if (*list_read_count > bytes_read) {
+		/* point to the start of unread data */
+		j = newpacket->length - (*list_read_count - bytes_read);
+		/* point to the offset in the packet buffer */
+		ptemp_buf = (u8 *) newpacket->data + j;
+		/*
+		 * check if there is enough room in
+		 * * the incoming buffer
+		 */
+		if (length > (*list_read_count - bytes_read))
+			/*
+			 * copy what ever is there in this
+			 * packet and move on
+			 */
+			bytes_copied = (*list_read_count - bytes_read);
+		else
+			/* copy the remaining */
+			bytes_copied = length;
+		memcpy(data, ptemp_buf, bytes_copied);
+	}
+	return bytes_copied;
+}
+
+static int packet_read_list(char *data, size_t * pread_length)
+{
+	struct packet_data *newpacket;
+	int temp_count = 0;
+	int bytes_copied = 0;
+	int bytes_read = 0;
+	int remaining_bytes = 0;
+	char *pdest = data;
+
+	/* check if we have any packets */
+	if (0 == rbu_data.num_packets)
+		return -ENOMEM;
+
+	remaining_bytes = *pread_length;
+	bytes_read = rbu_data.packet_read_count;
+
+	list_for_each_entry(newpacket, (&packet_data_head.list)->next, list) {
+		bytes_copied = do_packet_read(pdest, newpacket,
+			remaining_bytes, bytes_read, &temp_count);
+		remaining_bytes -= bytes_copied;
+		bytes_read += bytes_copied;
+		pdest += bytes_copied;
+		/*
+		 * check if we reached end of buffer before reaching the
+		 * last packet
+		 */
+		if (remaining_bytes == 0)
+			break;
+	}
+	/*finally set the bytes read */
+	*pread_length = bytes_read - rbu_data.packet_read_count;
+	rbu_data.packet_read_count = bytes_read;
+	return 0;
+}
+
+static void packet_empty_list(void)
+{
+	struct packet_data *newpacket, *tmp;
+
+	list_for_each_entry_safe(newpacket, tmp, (&packet_data_head.list)->next, list) {
+		list_del(&newpacket->list);
+
+		/*
+		 * zero out the RBU packet memory before freeing
+		 * to make sure there are no stale RBU packets left in memory
+		 */
+		memset(newpacket->data, 0, rbu_data.packetsize);
+		set_memory_wb((unsigned long)newpacket->data,
+			1 << newpacket->ordernum);
+		free_pages((unsigned long) newpacket->data,
+			newpacket->ordernum);
+		kfree(newpacket);
+	}
+	rbu_data.packet_read_count = 0;
+	rbu_data.num_packets = 0;
+	rbu_data.imagesize = 0;
+}
+
+/*
+ * img_update_free: Frees the buffer allocated for storing BIOS image
+ * Always called with lock held and returned with lock held
+ */
+static void img_update_free(void)
+{
+	if (!rbu_data.image_update_buffer)
+		return;
+	/*
+	 * zero out this buffer before freeing it to get rid of any stale
+	 * BIOS image copied in memory.
+	 */
+	memset(rbu_data.image_update_buffer, 0,
+		rbu_data.image_update_buffer_size);
+	free_pages((unsigned long) rbu_data.image_update_buffer,
+		rbu_data.image_update_ordernum);
+
+	/*
+	 * Re-initialize the rbu_data variables after a free
+	 */
+	rbu_data.image_update_ordernum = -1;
+	rbu_data.image_update_buffer = NULL;
+	rbu_data.image_update_buffer_size = 0;
+	rbu_data.bios_image_size = 0;
+}
+
+/*
+ * img_update_realloc: This function allocates the contiguous pages to
+ * accommodate the requested size of data. The memory address and size
+ * values are stored globally and on every call to this function the new
+ * size is checked to see if more data is required than the existing size.
+ * If true the previous memory is freed and new allocation is done to
+ * accommodate the new size. If the incoming size is less then than the
+ * already allocated size, then that memory is reused. This function is
+ * called with lock held and returns with lock held.
+ */
+static int img_update_realloc(unsigned long size)
+{
+	unsigned char *image_update_buffer = NULL;
+	unsigned long img_buf_phys_addr;
+	int ordernum;
+
+	/*
+	 * check if the buffer of sufficient size has been
+	 * already allocated
+	 */
+	if (rbu_data.image_update_buffer_size >= size) {
+		/*
+		 * check for corruption
+		 */
+		if ((size != 0) && (rbu_data.image_update_buffer == NULL)) {
+			pr_err("corruption check failed\n");
+			return -EINVAL;
+		}
+		/*
+		 * we have a valid pre-allocated buffer with
+		 * sufficient size
+		 */
+		return 0;
+	}
+
+	/*
+	 * free any previously allocated buffer
+	 */
+	img_update_free();
+
+	spin_unlock(&rbu_data.lock);
+
+	ordernum = get_order(size);
+	image_update_buffer =
+		(unsigned char *)__get_free_pages(GFP_DMA32, ordernum);
+	spin_lock(&rbu_data.lock);
+	if (!image_update_buffer) {
+		pr_debug("Not enough memory for image update: size = %ld\n", size);
+		return -ENOMEM;
+	}
+
+	img_buf_phys_addr = (unsigned long)virt_to_phys(image_update_buffer);
+	if (WARN_ON_ONCE(img_buf_phys_addr > BIOS_SCAN_LIMIT))
+		return -EINVAL; /* can't happen per definition */
+
+	rbu_data.image_update_buffer = image_update_buffer;
+	rbu_data.image_update_buffer_size = size;
+	rbu_data.bios_image_size = rbu_data.image_update_buffer_size;
+	rbu_data.image_update_ordernum = ordernum;
+	return 0;
+}
+
+static ssize_t read_packet_data(char *buffer, loff_t pos, size_t count)
+{
+	int retval;
+	size_t bytes_left;
+	size_t data_length;
+	char *ptempBuf = buffer;
+
+	/* check to see if we have something to return */
+	if (rbu_data.num_packets == 0) {
+		pr_debug("no packets written\n");
+		retval = -ENOMEM;
+		goto read_rbu_data_exit;
+	}
+
+	if (pos > rbu_data.imagesize) {
+		retval = 0;
+		pr_warn("data underrun\n");
+		goto read_rbu_data_exit;
+	}
+
+	bytes_left = rbu_data.imagesize - pos;
+	data_length = min(bytes_left, count);
+
+	if ((retval = packet_read_list(ptempBuf, &data_length)) < 0)
+		goto read_rbu_data_exit;
+
+	if ((pos + count) > rbu_data.imagesize) {
+		rbu_data.packet_read_count = 0;
+		/* this was the last copy */
+		retval = bytes_left;
+	} else
+		retval = count;
+
+      read_rbu_data_exit:
+	return retval;
+}
+
+static ssize_t read_rbu_mono_data(char *buffer, loff_t pos, size_t count)
+{
+	/* check to see if we have something to return */
+	if ((rbu_data.image_update_buffer == NULL) ||
+		(rbu_data.bios_image_size == 0)) {
+		pr_debug("image_update_buffer %p, bios_image_size %lu\n",
+			rbu_data.image_update_buffer,
+			rbu_data.bios_image_size);
+		return -ENOMEM;
+	}
+
+	return memory_read_from_buffer(buffer, count, &pos,
+			rbu_data.image_update_buffer, rbu_data.bios_image_size);
+}
+
+static ssize_t data_read(struct file *filp, struct kobject *kobj,
+			 struct bin_attribute *bin_attr,
+			 char *buffer, loff_t pos, size_t count)
+{
+	ssize_t ret_count = 0;
+
+	spin_lock(&rbu_data.lock);
+
+	if (!strcmp(image_type, "mono"))
+		ret_count = read_rbu_mono_data(buffer, pos, count);
+	else if (!strcmp(image_type, "packet"))
+		ret_count = read_packet_data(buffer, pos, count);
+	else
+		pr_debug("invalid image type specified\n");
+
+	spin_unlock(&rbu_data.lock);
+	return ret_count;
+}
+static BIN_ATTR_RO(data, 0);
+
+static void callbackfn_rbu(const struct firmware *fw, void *context)
+{
+	rbu_data.entry_created = 0;
+
+	if (!fw)
+		return;
+
+	if (!fw->size)
+		goto out;
+
+	spin_lock(&rbu_data.lock);
+	if (!strcmp(image_type, "mono")) {
+		if (!img_update_realloc(fw->size))
+			memcpy(rbu_data.image_update_buffer,
+				fw->data, fw->size);
+	} else if (!strcmp(image_type, "packet")) {
+		/*
+		 * we need to free previous packets if a
+		 * new hunk of packets needs to be downloaded
+		 */
+		packet_empty_list();
+		if (packetize_data(fw->data, fw->size))
+			/* Incase something goes wrong when we are
+			 * in middle of packetizing the data, we
+			 * need to free up whatever packets might
+			 * have been created before we quit.
+			 */
+			packet_empty_list();
+	} else
+		pr_debug("invalid image type specified\n");
+	spin_unlock(&rbu_data.lock);
+ out:
+	release_firmware(fw);
+}
+
+static ssize_t image_type_read(struct file *filp, struct kobject *kobj,
+			       struct bin_attribute *bin_attr,
+			       char *buffer, loff_t pos, size_t count)
+{
+	int size = 0;
+	if (!pos)
+		size = scnprintf(buffer, count, "%s\n", image_type);
+	return size;
+}
+
+static ssize_t image_type_write(struct file *filp, struct kobject *kobj,
+				struct bin_attribute *bin_attr,
+				char *buffer, loff_t pos, size_t count)
+{
+	int rc = count;
+	int req_firm_rc = 0;
+	int i;
+	spin_lock(&rbu_data.lock);
+	/*
+	 * Find the first newline or space
+	 */
+	for (i = 0; i < count; ++i)
+		if (buffer[i] == '\n' || buffer[i] == ' ') {
+			buffer[i] = '\0';
+			break;
+		}
+	if (i == count)
+		buffer[count] = '\0';
+
+	if (strstr(buffer, "mono"))
+		strcpy(image_type, "mono");
+	else if (strstr(buffer, "packet"))
+		strcpy(image_type, "packet");
+	else if (strstr(buffer, "init")) {
+		/*
+		 * If due to the user error the driver gets in a bad
+		 * state where even though it is loaded , the
+		 * /sys/class/firmware/dell_rbu entries are missing.
+		 * to cover this situation the user can recreate entries
+		 * by writing init to image_type.
+		 */
+		if (!rbu_data.entry_created) {
+			spin_unlock(&rbu_data.lock);
+			req_firm_rc = request_firmware_nowait(THIS_MODULE,
+				FW_ACTION_NOHOTPLUG, "dell_rbu",
+				&rbu_device->dev, GFP_KERNEL, &context,
+				callbackfn_rbu);
+			if (req_firm_rc) {
+				pr_err("request_firmware_nowait failed %d\n", rc);
+				rc = -EIO;
+			} else
+				rbu_data.entry_created = 1;
+
+			spin_lock(&rbu_data.lock);
+		}
+	} else {
+		pr_warn("image_type is invalid\n");
+		spin_unlock(&rbu_data.lock);
+		return -EINVAL;
+	}
+
+	/* we must free all previous allocations */
+	packet_empty_list();
+	img_update_free();
+	spin_unlock(&rbu_data.lock);
+
+	return rc;
+}
+static BIN_ATTR_RW(image_type, 0);
+
+static ssize_t packet_size_read(struct file *filp, struct kobject *kobj,
+				struct bin_attribute *bin_attr,
+				char *buffer, loff_t pos, size_t count)
+{
+	int size = 0;
+	if (!pos) {
+		spin_lock(&rbu_data.lock);
+		size = scnprintf(buffer, count, "%lu\n", rbu_data.packetsize);
+		spin_unlock(&rbu_data.lock);
+	}
+	return size;
+}
+
+static ssize_t packet_size_write(struct file *filp, struct kobject *kobj,
+				 struct bin_attribute *bin_attr,
+				 char *buffer, loff_t pos, size_t count)
+{
+	unsigned long temp;
+	spin_lock(&rbu_data.lock);
+	packet_empty_list();
+	sscanf(buffer, "%lu", &temp);
+	if (temp < 0xffffffff)
+		rbu_data.packetsize = temp;
+
+	spin_unlock(&rbu_data.lock);
+	return count;
+}
+static BIN_ATTR_RW(packet_size, 0);
+
+static struct bin_attribute *rbu_bin_attrs[] = {
+	&bin_attr_data,
+	&bin_attr_image_type,
+	&bin_attr_packet_size,
+	NULL
+};
+
+static const struct attribute_group rbu_group = {
+	.bin_attrs = rbu_bin_attrs,
+};
+
+static int __init dcdrbu_init(void)
+{
+	int rc;
+	spin_lock_init(&rbu_data.lock);
+
+	init_packet_head();
+	rbu_device = platform_device_register_simple("dell_rbu", -1, NULL, 0);
+	if (IS_ERR(rbu_device)) {
+		pr_err("platform_device_register_simple failed\n");
+		return PTR_ERR(rbu_device);
+	}
+
+	rc = sysfs_create_group(&rbu_device->dev.kobj, &rbu_group);
+	if (rc)
+		goto out_devreg;
+
+	rbu_data.entry_created = 0;
+	return 0;
+
+out_devreg:
+	platform_device_unregister(rbu_device);
+	return rc;
+}
+
+static __exit void dcdrbu_exit(void)
+{
+	spin_lock(&rbu_data.lock);
+	packet_empty_list();
+	img_update_free();
+	spin_unlock(&rbu_data.lock);
+	sysfs_remove_group(&rbu_device->dev.kobj, &rbu_group);
+	platform_device_unregister(rbu_device);
+}
+
+module_exit(dcdrbu_exit);
+module_init(dcdrbu_init);
+
+/* vim:noet:ts=8:sw=8
+*/