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dma-debug: add initialization code

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

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
This commit is contained in:
Joerg Roedel 2009-01-09 12:54:42 +01:00
parent 3b1e79ed73
commit 6bf078715c
2 changed files with 80 additions and 0 deletions
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14
include/linux/dma-debug.h
View file

@ -20,6 +20,20 @@
#ifndef __DMA_DEBUG_H #ifndef __DMA_DEBUG_H
#define __DMA_DEBUG_H #define __DMA_DEBUG_H
#include <linux/types.h>
struct device; 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 */ #endif /* __DMA_DEBUG_H */

66
lib/dma-debug.c
View file

@ -21,6 +21,7 @@
#include <linux/spinlock.h> #include <linux/spinlock.h>
#include <linux/types.h> #include <linux/types.h>
#include <linux/list.h> #include <linux/list.h>
#include <linux/slab.h>
#define HASH_SIZE 1024ULL #define HASH_SIZE 1024ULL
#define HASH_FN_SHIFT 13 #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); 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");
}