dma-debug: add initialization code

Impact: add code to initialize dma-debug core data structures Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

dma-debug: add initialization code
Impact: add code to initialize dma-debug core data structures Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Joerg Roedel
1 parent 3b1e79ed73
Showing 2 changed files with 80 additions and 0 deletions Side-by-side Diff
include/linux/dma-debug.h
lib/dma-debug.c
@@ -20,7 +20,21 @@
 #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 */
@@ -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
@@ -196,5 +197,70 @@
 	list_add(&entry->list, &free_entries);
 	num_free_entries += 1;
 	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");
 }
...	...	@@ -20,7 +20,21 @@
20	20	#ifndef __DMA_DEBUG_H
21	21	#define __DMA_DEBUG_H
22	22
	23	+#include <linux/types.h>
	24	+
23	25	struct device;
	26	+
	27	+#ifdef CONFIG_DMA_API_DEBUG
	28	+
	29	+extern void dma_debug_init(u32 num_entries);
	30	+
	31	+#else /* CONFIG_DMA_API_DEBUG */
	32	+
	33	+static inline void dma_debug_init(u32 num_entries)
	34	+{
	35	+}
	36	+
	37	+#endif /* CONFIG_DMA_API_DEBUG */
24	38
25	39	#endif /* __DMA_DEBUG_H */
...	...	@@ -21,6 +21,7 @@
21	21	#include <linux/spinlock.h>
22	22	#include <linux/types.h>
23	23	#include <linux/list.h>
	24	+#include <linux/slab.h>
24	25
25	26	#define HASH_SIZE 1024ULL
26	27	#define HASH_FN_SHIFT 13
...	...	@@ -196,5 +197,70 @@
196	197	list_add(&entry->list, &free_entries);
197	198	num_free_entries += 1;
198	199	spin_unlock_irqrestore(&free_entries_lock, flags);
	200	+}
	201	+
	202	+/*
	203	+ * DMA-API debugging init code
	204	+ *
	205	+ * The init code does two things:
	206	+ * 1. Initialize core data structures
	207	+ * 2. Preallocate a given number of dma_debug_entry structs
	208	+ */
	209	+
	210	+static int prealloc_memory(u32 num_entries)
	211	+{
	212	+ struct dma_debug_entry entry, next_entry;
	213	+ int i;
	214	+
	215	+ for (i = 0; i < num_entries; ++i) {
	216	+ entry = kzalloc(sizeof(*entry), GFP_KERNEL);
	217	+ if (!entry)
	218	+ goto out_err;
	219	+
	220	+ list_add_tail(&entry->list, &free_entries);
	221	+ }
	222	+
	223	+ num_free_entries = num_entries;
	224	+ min_free_entries = num_entries;
	225	+
	226	+ printk(KERN_INFO "DMA-API: preallocated %d debug entries\n",
	227	+ num_entries);
	228	+
	229	+ return 0;
	230	+
	231	+out_err:
	232	+
	233	+ list_for_each_entry_safe(entry, next_entry, &free_entries, list) {
	234	+ list_del(&entry->list);
	235	+ kfree(entry);
	236	+ }
	237	+
	238	+ return -ENOMEM;
	239	+}
	240	+
	241	+/*
	242	+ * Let the architectures decide how many entries should be preallocated.
	243	+ */
	244	+void dma_debug_init(u32 num_entries)
	245	+{
	246	+ int i;
	247	+
	248	+ if (global_disable)
	249	+ return;
	250	+
	251	+ for (i = 0; i < HASH_SIZE; ++i) {
	252	+ INIT_LIST_HEAD(&dma_entry_hash[i].list);
	253	+ dma_entry_hash[i].lock = SPIN_LOCK_UNLOCKED;
	254	+ }
	255	+
	256	+ if (prealloc_memory(num_entries) != 0) {
	257	+ printk(KERN_ERR "DMA-API: debugging out of memory error "
	258	+ "- disabled\n");
	259	+ global_disable = true;
	260	+
	261	+ return;
	262	+ }
	263	+
	264	+ printk(KERN_INFO "DMA-API: debugging enabled by kernel config\n");
199	265	}