1 files changed, 343 insertions, 0 deletions
diff --git a/drivers/firmware/efi/capsule-loader.c b/drivers/firmware/efi/capsule-loader.c
new file mode 100644
index 000000000..3e8d4b51a
--- /dev/null
+++ b/drivers/firmware/efi/capsule-loader.c
@@ -0,0 +1,343 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * EFI capsule loader driver.
+ *
+ * Copyright 2015 Intel Corporation
+ */
+
+#define pr_fmt(fmt) "efi: " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/miscdevice.h>
+#include <linux/highmem.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/mutex.h>
+#include <linux/efi.h>
+#include <linux/vmalloc.h>
+
+#define NO_FURTHER_WRITE_ACTION -1
+
+/**
+ * efi_free_all_buff_pages - free all previous allocated buffer pages
+ * @cap_info: pointer to current instance of capsule_info structure
+ *
+ *	In addition to freeing buffer pages, it flags NO_FURTHER_WRITE_ACTION
+ *	to cease processing data in subsequent write(2) calls until close(2)
+ *	is called.
+ **/
+static void efi_free_all_buff_pages(struct capsule_info *cap_info)
+{
+	while (cap_info->index > 0)
+		__free_page(cap_info->pages[--cap_info->index]);
+
+	cap_info->index = NO_FURTHER_WRITE_ACTION;
+}
+
+int __efi_capsule_setup_info(struct capsule_info *cap_info)
+{
+	size_t pages_needed;
+	int ret;
+	void *temp_page;
+
+	pages_needed = ALIGN(cap_info->total_size, PAGE_SIZE) / PAGE_SIZE;
+
+	if (pages_needed == 0) {
+		pr_err("invalid capsule size\n");
+		return -EINVAL;
+	}
+
+	/* Check if the capsule binary supported */
+	ret = efi_capsule_supported(cap_info->header.guid,
+				    cap_info->header.flags,
+				    cap_info->header.imagesize,
+				    &cap_info->reset_type);
+	if (ret) {
+		pr_err("capsule not supported\n");
+		return ret;
+	}
+
+	temp_page = krealloc(cap_info->pages,
+			     pages_needed * sizeof(void *),
+			     GFP_KERNEL | __GFP_ZERO);
+	if (!temp_page)
+		return -ENOMEM;
+
+	cap_info->pages = temp_page;
+
+	temp_page = krealloc(cap_info->phys,
+			     pages_needed * sizeof(phys_addr_t *),
+			     GFP_KERNEL | __GFP_ZERO);
+	if (!temp_page)
+		return -ENOMEM;
+
+	cap_info->phys = temp_page;
+
+	return 0;
+}
+
+/**
+ * efi_capsule_setup_info - obtain the efi capsule header in the binary and
+ *			    setup capsule_info structure
+ * @cap_info: pointer to current instance of capsule_info structure
+ * @kbuff: a mapped first page buffer pointer
+ * @hdr_bytes: the total received number of bytes for efi header
+ *
+ * Platforms with non-standard capsule update mechanisms can override
+ * this __weak function so they can perform any required capsule
+ * image munging. See quark_quirk_function() for an example.
+ **/
+int __weak efi_capsule_setup_info(struct capsule_info *cap_info, void *kbuff,
+				  size_t hdr_bytes)
+{
+	/* Only process data block that is larger than efi header size */
+	if (hdr_bytes < sizeof(efi_capsule_header_t))
+		return 0;
+
+	memcpy(&cap_info->header, kbuff, sizeof(cap_info->header));
+	cap_info->total_size = cap_info->header.imagesize;
+
+	return __efi_capsule_setup_info(cap_info);
+}
+
+/**
+ * efi_capsule_submit_update - invoke the efi_capsule_update API once binary
+ *			       upload done
+ * @cap_info: pointer to current instance of capsule_info structure
+ **/
+static ssize_t efi_capsule_submit_update(struct capsule_info *cap_info)
+{
+	bool do_vunmap = false;
+	int ret;
+
+	/*
+	 * cap_info->capsule may have been assigned already by a quirk
+	 * handler, so only overwrite it if it is NULL
+	 */
+	if (!cap_info->capsule) {
+		cap_info->capsule = vmap(cap_info->pages, cap_info->index,
+					 VM_MAP, PAGE_KERNEL);
+		if (!cap_info->capsule)
+			return -ENOMEM;
+		do_vunmap = true;
+	}
+
+	ret = efi_capsule_update(cap_info->capsule, cap_info->phys);
+	if (do_vunmap)
+		vunmap(cap_info->capsule);
+	if (ret) {
+		pr_err("capsule update failed\n");
+		return ret;
+	}
+
+	/* Indicate capsule binary uploading is done */
+	cap_info->index = NO_FURTHER_WRITE_ACTION;
+
+	if (cap_info->header.flags & EFI_CAPSULE_PERSIST_ACROSS_RESET) {
+		pr_info("Successfully uploaded capsule file with reboot type '%s'\n",
+			!cap_info->reset_type ? "RESET_COLD" :
+			cap_info->reset_type == 1 ? "RESET_WARM" :
+			"RESET_SHUTDOWN");
+	} else {
+		pr_info("Successfully processed capsule file\n");
+	}
+
+	return 0;
+}
+
+/**
+ * efi_capsule_write - store the capsule binary and pass it to
+ *		       efi_capsule_update() API
+ * @file: file pointer
+ * @buff: buffer pointer
+ * @count: number of bytes in @buff
+ * @offp: not used
+ *
+ *	Expectation:
+ *	- A user space tool should start at the beginning of capsule binary and
+ *	  pass data in sequentially.
+ *	- Users should close and re-open this file note in order to upload more
+ *	  capsules.
+ *	- After an error returned, user should close the file and restart the
+ *	  operation for the next try otherwise -EIO will be returned until the
+ *	  file is closed.
+ *	- An EFI capsule header must be located at the beginning of capsule
+ *	  binary file and passed in as first block data of write operation.
+ **/
+static ssize_t efi_capsule_write(struct file *file, const char __user *buff,
+				 size_t count, loff_t *offp)
+{
+	int ret;
+	struct capsule_info *cap_info = file->private_data;
+	struct page *page;
+	void *kbuff = NULL;
+	size_t write_byte;
+
+	if (count == 0)
+		return 0;
+
+	/* Return error while NO_FURTHER_WRITE_ACTION is flagged */
+	if (cap_info->index < 0)
+		return -EIO;
+
+	/* Only alloc a new page when previous page is full */
+	if (!cap_info->page_bytes_remain) {
+		page = alloc_page(GFP_KERNEL);
+		if (!page) {
+			ret = -ENOMEM;
+			goto failed;
+		}
+
+		cap_info->pages[cap_info->index] = page;
+		cap_info->phys[cap_info->index] = page_to_phys(page);
+		cap_info->page_bytes_remain = PAGE_SIZE;
+		cap_info->index++;
+	} else {
+		page = cap_info->pages[cap_info->index - 1];
+	}
+
+	kbuff = kmap(page);
+	kbuff += PAGE_SIZE - cap_info->page_bytes_remain;
+
+	/* Copy capsule binary data from user space to kernel space buffer */
+	write_byte = min_t(size_t, count, cap_info->page_bytes_remain);
+	if (copy_from_user(kbuff, buff, write_byte)) {
+		ret = -EFAULT;
+		goto fail_unmap;
+	}
+	cap_info->page_bytes_remain -= write_byte;
+
+	/* Setup capsule binary info structure */
+	if (cap_info->header.headersize == 0) {
+		ret = efi_capsule_setup_info(cap_info, kbuff - cap_info->count,
+					     cap_info->count + write_byte);
+		if (ret)
+			goto fail_unmap;
+	}
+
+	cap_info->count += write_byte;
+	kunmap(page);
+
+	/* Submit the full binary to efi_capsule_update() API */
+	if (cap_info->header.headersize > 0 &&
+	    cap_info->count >= cap_info->total_size) {
+		if (cap_info->count > cap_info->total_size) {
+			pr_err("capsule upload size exceeded header defined size\n");
+			ret = -EINVAL;
+			goto failed;
+		}
+
+		ret = efi_capsule_submit_update(cap_info);
+		if (ret)
+			goto failed;
+	}
+
+	return write_byte;
+
+fail_unmap:
+	kunmap(page);
+failed:
+	efi_free_all_buff_pages(cap_info);
+	return ret;
+}
+
+/**
+ * efi_capsule_release - called by file close
+ * @inode: not used
+ * @file: file pointer
+ *
+ *	We will not free successfully submitted pages since efi update
+ *	requires data to be maintained across system reboot.
+ **/
+static int efi_capsule_release(struct inode *inode, struct file *file)
+{
+	struct capsule_info *cap_info = file->private_data;
+
+	if (cap_info->index > 0 &&
+	    (cap_info->header.headersize == 0 ||
+	     cap_info->count < cap_info->total_size)) {
+		pr_err("capsule upload not complete\n");
+		efi_free_all_buff_pages(cap_info);
+	}
+
+	kfree(cap_info->pages);
+	kfree(cap_info->phys);
+	kfree(file->private_data);
+	file->private_data = NULL;
+	return 0;
+}
+
+/**
+ * efi_capsule_open - called by file open
+ * @inode: not used
+ * @file: file pointer
+ *
+ *	Will allocate each capsule_info memory for each file open call.
+ *	This provided the capability to support multiple file open feature
+ *	where user is not needed to wait for others to finish in order to
+ *	upload their capsule binary.
+ **/
+static int efi_capsule_open(struct inode *inode, struct file *file)
+{
+	struct capsule_info *cap_info;
+
+	cap_info = kzalloc(sizeof(*cap_info), GFP_KERNEL);
+	if (!cap_info)
+		return -ENOMEM;
+
+	cap_info->pages = kzalloc(sizeof(void *), GFP_KERNEL);
+	if (!cap_info->pages) {
+		kfree(cap_info);
+		return -ENOMEM;
+	}
+
+	cap_info->phys = kzalloc(sizeof(void *), GFP_KERNEL);
+	if (!cap_info->phys) {
+		kfree(cap_info->pages);
+		kfree(cap_info);
+		return -ENOMEM;
+	}
+
+	file->private_data = cap_info;
+
+	return 0;
+}
+
+static const struct file_operations efi_capsule_fops = {
+	.owner = THIS_MODULE,
+	.open = efi_capsule_open,
+	.write = efi_capsule_write,
+	.release = efi_capsule_release,
+	.llseek = no_llseek,
+};
+
+static struct miscdevice efi_capsule_misc = {
+	.minor = MISC_DYNAMIC_MINOR,
+	.name = "efi_capsule_loader",
+	.fops = &efi_capsule_fops,
+};
+
+static int __init efi_capsule_loader_init(void)
+{
+	int ret;
+
+	if (!efi_enabled(EFI_RUNTIME_SERVICES))
+		return -ENODEV;
+
+	ret = misc_register(&efi_capsule_misc);
+	if (ret)
+		pr_err("Unable to register capsule loader device\n");
+
+	return ret;
+}
+module_init(efi_capsule_loader_init);
+
+static void __exit efi_capsule_loader_exit(void)
+{
+	misc_deregister(&efi_capsule_misc);
+}
+module_exit(efi_capsule_loader_exit);
+
+MODULE_DESCRIPTION("EFI capsule firmware binary loader");
+MODULE_LICENSE("GPL v2");