diff options
Diffstat (limited to 'arch/x86/kernel/kdebugfs.c')
| -rw-r--r-- | arch/x86/kernel/kdebugfs.c | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/arch/x86/kernel/kdebugfs.c b/arch/x86/kernel/kdebugfs.c new file mode 100644 index 0000000000..e2e89bebcb --- /dev/null +++ b/arch/x86/kernel/kdebugfs.c @@ -0,0 +1,195 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Architecture specific debugfs files + * + * Copyright (C) 2007, Intel Corp. + * Huang Ying <ying.huang@intel.com> + */ +#include <linux/debugfs.h> +#include <linux/uaccess.h> +#include <linux/export.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; + 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 + pos; + + /* Is it direct data or invalid indirect one? */ + if (!(node->type & SETUP_INDIRECT) || node->type == SETUP_INDIRECT) + pa += sizeof(struct setup_data); + + p = memremap(pa, count, MEMREMAP_WB); + if (!p) + return -ENOMEM; + + remain = copy_to_user(user_buf, p, count); + + memunmap(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 void __init +create_setup_data_node(struct dentry *parent, int no, + struct setup_data_node *node) +{ + struct dentry *d; + char buf[16]; + + sprintf(buf, "%d", no); + d = debugfs_create_dir(buf, parent); + + debugfs_create_x32("type", S_IRUGO, d, &node->type); + debugfs_create_file("data", S_IRUGO, d, node, &fops_setup_data); +} + +static int __init create_setup_data_nodes(struct dentry *parent) +{ + struct setup_indirect *indirect; + struct setup_data_node *node; + struct setup_data *data; + u64 pa_data, pa_next; + struct dentry *d; + int error; + u32 len; + int no = 0; + + d = debugfs_create_dir("setup_data", parent); + + pa_data = boot_params.hdr.setup_data; + + while (pa_data) { + node = kmalloc(sizeof(*node), GFP_KERNEL); + if (!node) { + error = -ENOMEM; + goto err_dir; + } + + data = memremap(pa_data, sizeof(*data), MEMREMAP_WB); + if (!data) { + kfree(node); + error = -ENOMEM; + goto err_dir; + } + pa_next = data->next; + + if (data->type == SETUP_INDIRECT) { + len = sizeof(*data) + data->len; + memunmap(data); + data = memremap(pa_data, len, MEMREMAP_WB); + if (!data) { + kfree(node); + error = -ENOMEM; + goto err_dir; + } + + indirect = (struct setup_indirect *)data->data; + + if (indirect->type != SETUP_INDIRECT) { + node->paddr = indirect->addr; + node->type = indirect->type; + node->len = indirect->len; + } else { + node->paddr = pa_data; + node->type = data->type; + node->len = data->len; + } + } else { + node->paddr = pa_data; + node->type = data->type; + node->len = data->len; + } + + create_setup_data_node(d, no, node); + pa_data = pa_next; + + memunmap(data); + no++; + } + + return 0; + +err_dir: + debugfs_remove_recursive(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; + int error; + + dbp = debugfs_create_dir("boot_params", arch_debugfs_dir); + + debugfs_create_x16("version", S_IRUGO, dbp, &boot_params.hdr.version); + debugfs_create_blob("data", S_IRUGO, dbp, &boot_params_blob); + + error = create_setup_data_nodes(dbp); + if (error) + debugfs_remove_recursive(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); + +#ifdef CONFIG_DEBUG_BOOT_PARAMS + error = boot_params_kdebugfs_init(); +#endif + + return error; +} +arch_initcall(arch_kdebugfs_init); |