File-copy from v4.4.100
This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Please refer to that tree for all history prior to this point.
Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/arch/x86/kernel/kdebugfs.c b/arch/x86/kernel/kdebugfs.c
new file mode 100644
index 0000000..dc1404b
--- /dev/null
+++ b/arch/x86/kernel/kdebugfs.c
@@ -0,0 +1,214 @@
+/*
+ * Architecture specific debugfs files
+ *
+ * Copyright (C) 2007, Intel Corp.
+ * Huang Ying <ying.huang@intel.com>
+ *
+ * This file is released under the GPLv2.
+ */
+#include <linux/debugfs.h>
+#include <linux/uaccess.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/stat.h>
+#include <linux/io.h>
+#include <linux/mm.h>
+
+#include <asm/setup.h>
+
+struct dentry *arch_debugfs_dir;
+EXPORT_SYMBOL(arch_debugfs_dir);
+
+#ifdef CONFIG_DEBUG_BOOT_PARAMS
+struct setup_data_node {
+ u64 paddr;
+ u32 type;
+ u32 len;
+};
+
+static ssize_t setup_data_read(struct file *file, char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ struct setup_data_node *node = file->private_data;
+ unsigned long remain;
+ loff_t pos = *ppos;
+ struct page *pg;
+ void *p;
+ u64 pa;
+
+ if (pos < 0)
+ return -EINVAL;
+
+ if (pos >= node->len)
+ return 0;
+
+ if (count > node->len - pos)
+ count = node->len - pos;
+
+ pa = node->paddr + sizeof(struct setup_data) + pos;
+ pg = pfn_to_page((pa + count - 1) >> PAGE_SHIFT);
+ if (PageHighMem(pg)) {
+ p = ioremap_cache(pa, count);
+ if (!p)
+ return -ENXIO;
+ } else
+ p = __va(pa);
+
+ remain = copy_to_user(user_buf, p, count);
+
+ if (PageHighMem(pg))
+ iounmap(p);
+
+ if (remain)
+ return -EFAULT;
+
+ *ppos = pos + count;
+
+ return count;
+}
+
+static const struct file_operations fops_setup_data = {
+ .read = setup_data_read,
+ .open = simple_open,
+ .llseek = default_llseek,
+};
+
+static int __init
+create_setup_data_node(struct dentry *parent, int no,
+ struct setup_data_node *node)
+{
+ struct dentry *d, *type, *data;
+ char buf[16];
+
+ sprintf(buf, "%d", no);
+ d = debugfs_create_dir(buf, parent);
+ if (!d)
+ return -ENOMEM;
+
+ type = debugfs_create_x32("type", S_IRUGO, d, &node->type);
+ if (!type)
+ goto err_dir;
+
+ data = debugfs_create_file("data", S_IRUGO, d, node, &fops_setup_data);
+ if (!data)
+ goto err_type;
+
+ return 0;
+
+err_type:
+ debugfs_remove(type);
+err_dir:
+ debugfs_remove(d);
+ return -ENOMEM;
+}
+
+static int __init create_setup_data_nodes(struct dentry *parent)
+{
+ struct setup_data_node *node;
+ struct setup_data *data;
+ int error;
+ struct dentry *d;
+ struct page *pg;
+ u64 pa_data;
+ int no = 0;
+
+ d = debugfs_create_dir("setup_data", parent);
+ if (!d)
+ return -ENOMEM;
+
+ pa_data = boot_params.hdr.setup_data;
+
+ while (pa_data) {
+ node = kmalloc(sizeof(*node), GFP_KERNEL);
+ if (!node) {
+ error = -ENOMEM;
+ goto err_dir;
+ }
+
+ pg = pfn_to_page((pa_data+sizeof(*data)-1) >> PAGE_SHIFT);
+ if (PageHighMem(pg)) {
+ data = ioremap_cache(pa_data, sizeof(*data));
+ if (!data) {
+ kfree(node);
+ error = -ENXIO;
+ goto err_dir;
+ }
+ } else
+ data = __va(pa_data);
+
+ node->paddr = pa_data;
+ node->type = data->type;
+ node->len = data->len;
+ error = create_setup_data_node(d, no, node);
+ pa_data = data->next;
+
+ if (PageHighMem(pg))
+ iounmap(data);
+ if (error)
+ goto err_dir;
+ no++;
+ }
+
+ return 0;
+
+err_dir:
+ debugfs_remove(d);
+ return error;
+}
+
+static struct debugfs_blob_wrapper boot_params_blob = {
+ .data = &boot_params,
+ .size = sizeof(boot_params),
+};
+
+static int __init boot_params_kdebugfs_init(void)
+{
+ struct dentry *dbp, *version, *data;
+ int error = -ENOMEM;
+
+ dbp = debugfs_create_dir("boot_params", NULL);
+ if (!dbp)
+ return -ENOMEM;
+
+ version = debugfs_create_x16("version", S_IRUGO, dbp,
+ &boot_params.hdr.version);
+ if (!version)
+ goto err_dir;
+
+ data = debugfs_create_blob("data", S_IRUGO, dbp,
+ &boot_params_blob);
+ if (!data)
+ goto err_version;
+
+ error = create_setup_data_nodes(dbp);
+ if (error)
+ goto err_data;
+
+ return 0;
+
+err_data:
+ debugfs_remove(data);
+err_version:
+ debugfs_remove(version);
+err_dir:
+ debugfs_remove(dbp);
+ return error;
+}
+#endif /* CONFIG_DEBUG_BOOT_PARAMS */
+
+static int __init arch_kdebugfs_init(void)
+{
+ int error = 0;
+
+ arch_debugfs_dir = debugfs_create_dir("x86", NULL);
+ if (!arch_debugfs_dir)
+ return -ENOMEM;
+
+#ifdef CONFIG_DEBUG_BOOT_PARAMS
+ error = boot_params_kdebugfs_init();
+#endif
+
+ return error;
+}
+arch_initcall(arch_kdebugfs_init);