arch/x86/kernel/kdebugfs.c

Source file repositories/reference/linux-study-clean/arch/x86/kernel/kdebugfs.c

File Facts

System
Linux kernel
Corpus path
arch/x86/kernel/kdebugfs.c
Extension
.c
Size
3898 bytes
Lines
196
Domain
Architecture Layer
Bucket
arch/x86
Inferred role
Architecture Layer: operation-table or driver-model contract
Status
pattern implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

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_obj(*node);
		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;
}

Annotation

Implementation Notes