diff options
| -rw-r--r-- | include/linux/dma-debug.h | 14 | ||||
| -rw-r--r-- | lib/dma-debug.c | 66 |
2 files changed, 80 insertions, 0 deletions
diff --git a/include/linux/dma-debug.h b/include/linux/dma-debug.h index ce4ace707c7..345d5387a30 100644 --- a/include/linux/dma-debug.h +++ b/include/linux/dma-debug.h @@ -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 */ diff --git a/lib/dma-debug.c b/lib/dma-debug.c index b6091466965..5b50bb31f7c 100644 --- a/lib/dma-debug.c +++ b/lib/dma-debug.c @@ -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"); +} + |