Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 6bf07871 authored by Joerg Roedel's avatar Joerg Roedel
Browse files

dma-debug: add initialization code 



Impact: add code to initialize dma-debug core data structures

Signed-off-by: default avatarJoerg Roedel <joerg.roedel@amd.com>
parent 3b1e79ed

include/linux/dma-debug.h

+14 −0
Original line number Diff line number Diff line
@@ -20,6 +20,20 @@ 
#ifndef __DMA_DEBUG_H

#define __DMA_DEBUG_H



#include <linux/types.h>



struct device;



#ifdef CONFIG_DMA_API_DEBUG



extern void dma_debug_init(u32 num_entries);



#else /* CONFIG_DMA_API_DEBUG */



static inline void dma_debug_init(u32 num_entries)

{

}



#endif /* CONFIG_DMA_API_DEBUG */



#endif /* __DMA_DEBUG_H */

lib/dma-debug.c

+66 −0
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ 
#include <linux/spinlock.h>

#include <linux/types.h>

#include <linux/list.h>

#include <linux/slab.h>



#define HASH_SIZE       1024ULL

#define HASH_FN_SHIFT   13
@@ -198,3 +199,68 @@ static void dma_entry_free(struct dma_debug_entry *entry) 
	spin_unlock_irqrestore(&free_entries_lock, flags);

}



/*

 * DMA-API debugging init code

 *

 * The init code does two things:

 *   1. Initialize core data structures

 *   2. Preallocate a given number of dma_debug_entry structs

 */



static int prealloc_memory(u32 num_entries)

{

	struct dma_debug_entry *entry, *next_entry;

	int i;



	for (i = 0; i < num_entries; ++i) {

		entry = kzalloc(sizeof(*entry), GFP_KERNEL);

		if (!entry)

			goto out_err;



		list_add_tail(&entry->list, &free_entries);

	}



	num_free_entries = num_entries;

	min_free_entries = num_entries;



	printk(KERN_INFO "DMA-API: preallocated %d debug entries\n",

			num_entries);



	return 0;



out_err:



	list_for_each_entry_safe(entry, next_entry, &free_entries, list) {

		list_del(&entry->list);

		kfree(entry);

	}



	return -ENOMEM;

}



/*

 * Let the architectures decide how many entries should be preallocated.

 */

void dma_debug_init(u32 num_entries)

{

	int i;



	if (global_disable)

		return;



	for (i = 0; i < HASH_SIZE; ++i) {

		INIT_LIST_HEAD(&dma_entry_hash[i].list);

		dma_entry_hash[i].lock = SPIN_LOCK_UNLOCKED;

	}



	if (prealloc_memory(num_entries) != 0) {

		printk(KERN_ERR "DMA-API: debugging out of memory error "

				"- disabled\n");

		global_disable = true;



		return;

	}



	printk(KERN_INFO "DMA-API: debugging enabled by kernel config\n");

}