// SPDX-License-Identifier: GPL-2.0/* * CMA DebugFS Interface * * Copyright (c) 2015 Sasha Levin <sasha.levin@oracle.com> */  #include <linux/debugfs.h>#include <linux/cma.h>#include <linux/list.h>#include <linux/kernel.h>#include <linux/slab.h>#include <linux/mm_types.h> #include "cma.h" struct cma_mem {	struct hlist_node node;	struct page *p;	unsigned long n;}; static int cma_debugfs_get(void *data, u64 *val){	unsigned long *p = data; 	*val = *p; 	return 0;}DEFINE_DEBUGFS_ATTRIBUTE(cma_debugfs_fops, cma_debugfs_get, NULL, "%llu\n"); static int cma_used_get(void *data, u64 *val){	struct cma *cma = data;	unsigned long used; 	spin_lock_irq(&cma->lock);	/* pages counter is smaller than sizeof(int) */	used = bitmap_weight(cma->bitmap, (int)cma_bitmap_maxno(cma));	spin_unlock_irq(&cma->lock);	*val = (u64)used << cma->order_per_bit; 	return 0;}DEFINE_DEBUGFS_ATTRIBUTE(cma_used_fops, cma_used_get, NULL, "%llu\n"); static int cma_maxchunk_get(void *data, u64 *val){	struct cma *cma = data;	unsigned long maxchunk = 0;	unsigned long start, end = 0;	unsigned long bitmap_maxno = cma_bitmap_maxno(cma); 	spin_lock_irq(&cma->lock);	for (;;) {		start = find_next_zero_bit(cma->bitmap, bitmap_maxno, end);		if (start >= bitmap_maxno)			break;		end = find_next_bit(cma->bitmap, bitmap_maxno, start);		maxchunk = max(end - start, maxchunk);	}	spin_unlock_irq(&cma->lock);	*val = (u64)maxchunk << cma->order_per_bit; 	return 0;}DEFINE_DEBUGFS_ATTRIBUTE(cma_maxchunk_fops, cma_maxchunk_get, NULL, "%llu\n"); static void cma_add_to_cma_mem_list(struct cma *cma, struct cma_mem *mem){	spin_lock(&cma->mem_head_lock);	hlist_add_head(&mem->node, &cma->mem_head);	spin_unlock(&cma->mem_head_lock);} static struct cma_mem *cma_get_entry_from_list(struct cma *cma){	struct cma_mem *mem = NULL; 	spin_lock(&cma->mem_head_lock);	if (!hlist_empty(&cma->mem_head)) {		mem = hlist_entry(cma->mem_head.first, struct cma_mem, node);		hlist_del_init(&mem->node);	}	spin_unlock(&cma->mem_head_lock); 	return mem;} static int cma_free_mem(struct cma *cma, int count){	struct cma_mem *mem = NULL; 	while (count) {		mem = cma_get_entry_from_list(cma);		if (mem == NULL)			return 0; 		if (mem->n <= count) {			cma_release(cma, mem->p, mem->n);			count -= mem->n;			kfree(mem);		} else if (cma->order_per_bit == 0) {			cma_release(cma, mem->p, count);			mem->p += count;			mem->n -= count;			count = 0;			cma_add_to_cma_mem_list(cma, mem);		} else {			pr_debug("cma: cannot release partial block when order_per_bit != 0\n");			cma_add_to_cma_mem_list(cma, mem);			break;		}	} 	return 0; } static int cma_free_write(void *data, u64 val){	int pages = val;	struct cma *cma = data; 	return cma_free_mem(cma, pages);}DEFINE_DEBUGFS_ATTRIBUTE(cma_free_fops, NULL, cma_free_write, "%llu\n"); static int cma_alloc_mem(struct cma *cma, int count){	struct cma_mem *mem;	struct page *p; 	mem = kzalloc(sizeof(*mem), GFP_KERNEL);	if (!mem)		return -ENOMEM; 	p = cma_alloc(cma, count, 0, false);	if (!p) {		kfree(mem);		return -ENOMEM;	} 	mem->p = p;	mem->n = count; 	cma_add_to_cma_mem_list(cma, mem); 	return 0;} static int cma_alloc_write(void *data, u64 val){	int pages = val;	struct cma *cma = data; 	return cma_alloc_mem(cma, pages);}DEFINE_DEBUGFS_ATTRIBUTE(cma_alloc_fops, NULL, cma_alloc_write, "%llu\n"); static void cma_debugfs_add_one(struct cma *cma, struct dentry *root_dentry){	struct dentry *tmp; 	tmp = debugfs_create_dir(cma->name, root_dentry); 	debugfs_create_file("alloc", 0200, tmp, cma, &cma_alloc_fops);	debugfs_create_file("free", 0200, tmp, cma, &cma_free_fops);	debugfs_create_file("base_pfn", 0444, tmp,			    &cma->base_pfn, &cma_debugfs_fops);	debugfs_create_file("count", 0444, tmp, &cma->count, &cma_debugfs_fops);	debugfs_create_file("order_per_bit", 0444, tmp,			    &cma->order_per_bit, &cma_debugfs_fops);	debugfs_create_file("used", 0444, tmp, cma, &cma_used_fops);	debugfs_create_file("maxchunk", 0444, tmp, cma, &cma_maxchunk_fops); 	cma->dfs_bitmap.array = (u32 *)cma->bitmap;	cma->dfs_bitmap.n_elements = DIV_ROUND_UP(cma_bitmap_maxno(cma),						  BITS_PER_BYTE * sizeof(u32));	debugfs_create_u32_array("bitmap", 0444, tmp, &cma->dfs_bitmap);} static int __init cma_debugfs_init(void){	struct dentry *cma_debugfs_root;	int i; 	cma_debugfs_root = debugfs_create_dir("cma", NULL); 	for (i = 0; i < cma_area_count; i++)		cma_debugfs_add_one(&cma_areas[i], cma_debugfs_root); 	return 0;}late_initcall(cma_debugfs_init);