From: Joerg Roedel <joerg.roedel@amd.com>
To: linux-kernel@vger.kernel.org
Cc: mingo@redhat.com, dwmw2@infradead.org,
fujita.tomonori@lab.ntt.co.jp, netdev@vger.kernel.org,
iommu@lists.linux-foundation.org,
Joerg Roedel <joerg.roedel@amd.com>
Subject: [PATCH 03/16] dma-debug: add hash functions for dma_debug_entries
Date: Fri, 9 Jan 2009 17:19:17 +0100 [thread overview]
Message-ID: <1231517970-20288-4-git-send-email-joerg.roedel@amd.com> (raw)
In-Reply-To: <1231517970-20288-1-git-send-email-joerg.roedel@amd.com>
Impact: implement necessary functions for the core hash
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
---
lib/dma-debug.c | 101 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 101 insertions(+), 0 deletions(-)
diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index d04f8b6..74a0f36 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -18,9 +18,14 @@
*/
#include <linux/dma-debug.h>
+#include <linux/spinlock.h>
#include <linux/types.h>
#include <linux/list.h>
+#define HASH_SIZE 256
+#define HASH_FN_SHIFT 20
+#define HASH_FN_MASK 0xffULL
+
enum {
dma_debug_single,
dma_debug_sg,
@@ -37,3 +42,99 @@ struct dma_debug_entry {
int direction;
};
+struct hash_bucket {
+ struct list_head list;
+ spinlock_t lock;
+} ____cacheline_aligned;
+
+/* Hash list to save the allocated dma addresses */
+static struct hash_bucket dma_entry_hash[HASH_SIZE];
+
+/*
+ * Hash related functions
+ *
+ * Every DMA-API request is saved into a struct dma_debug_entry. To
+ * have quick access to these structs they are stored into a hash.
+ */
+static int hash_fn(struct dma_debug_entry *entry)
+{
+ /*
+ * Hash function is based on the dma address.
+ * We use bits 20-27 here as the index into the hash
+ */
+ return (entry->dev_addr >> HASH_FN_SHIFT) & HASH_FN_MASK;
+}
+
+/*
+ * Request exclusive access to a hash bucket for a given dma_debug_entry.
+ */
+static struct hash_bucket *get_hash_bucket(struct dma_debug_entry *entry,
+ unsigned long *flags)
+{
+ int idx = hash_fn(entry);
+ unsigned long __flags;
+
+ spin_lock_irqsave(&dma_entry_hash[idx].lock, __flags);
+ *flags = __flags;
+ return &dma_entry_hash[idx];
+}
+
+/*
+ * Give up exclusive access to the hash bucket
+ */
+static void put_hash_bucket(struct hash_bucket *bucket,
+ unsigned long *flags)
+{
+ unsigned long __flags = *flags;
+
+ spin_unlock_irqrestore(&bucket->lock, __flags);
+}
+
+/*
+ * Search a given entry in the hash bucket list
+ */
+static struct dma_debug_entry *hash_bucket_find(struct hash_bucket *bucket,
+ struct dma_debug_entry *ref)
+{
+ struct dma_debug_entry *entry;
+
+ list_for_each_entry(entry, &bucket->list, list) {
+ if ((entry->dev_addr == ref->dev_addr) &&
+ (entry->dev == ref->dev))
+ return entry;
+ }
+
+ return NULL;
+}
+
+/*
+ * Add an entry to a hash bucket
+ */
+static void hash_bucket_add(struct hash_bucket *bucket,
+ struct dma_debug_entry *entry)
+{
+ list_add_tail(&entry->list, &bucket->list);
+}
+
+/*
+ * Remove entry from a hash bucket list
+ */
+static void hash_bucket_del(struct dma_debug_entry *entry)
+{
+ list_del(&entry->list);
+}
+
+/*
+ * Wrapper function for adding an entry to the hash.
+ * This function takes care of locking itself.
+ */
+static void add_dma_entry(struct dma_debug_entry *entry)
+{
+ struct hash_bucket *bucket;
+ unsigned long flags;
+
+ bucket = get_hash_bucket(entry, &flags);
+ hash_bucket_add(bucket, entry);
+ put_hash_bucket(bucket, &flags);
+}
+
--
1.5.6.4
next prev parent reply other threads:[~2009-01-09 16:22 UTC|newest]
Thread overview: 73+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-01-09 16:19 [PATCH 0/16] DMA-API debugging facility v2 Joerg Roedel
2009-01-09 16:19 ` [PATCH 01/16] dma-debug: add Kconfig entry Joerg Roedel
2009-01-09 20:12 ` Randy Dunlap
2009-01-09 16:19 ` [PATCH 02/16] dma-debug: add header file and core data structures Joerg Roedel
2009-01-11 6:25 ` FUJITA Tomonori
2009-01-09 16:19 ` Joerg Roedel [this message]
2009-01-09 17:55 ` [PATCH 03/16] dma-debug: add hash functions for dma_debug_entries Evgeniy Polyakov
2009-01-09 18:14 ` Joerg Roedel
2009-01-09 18:23 ` Evgeniy Polyakov
2009-01-09 18:40 ` Joerg Roedel
2009-01-13 8:51 ` Andrew Morton
2009-01-13 8:59 ` David Woodhouse
2009-01-14 11:43 ` Ingo Molnar
2009-01-14 17:39 ` Andrew Morton
2009-01-14 17:43 ` Ingo Molnar
2009-01-14 17:48 ` Ingo Molnar
2009-01-15 3:44 ` FUJITA Tomonori
2009-01-14 17:48 ` David Woodhouse
2009-01-14 17:51 ` Joerg Roedel
2009-01-09 16:19 ` [PATCH 04/16] dma-debug: add allocator code Joerg Roedel
2009-01-10 23:43 ` Ingo Molnar
2009-01-09 16:19 ` [PATCH 05/16] dma-debug: add initialization code Joerg Roedel
2009-01-09 17:58 ` Evgeniy Polyakov
2009-01-09 18:17 ` Joerg Roedel
2009-01-09 16:19 ` [PATCH 06/16] dma-debug: add kernel command line parameters Joerg Roedel
2009-01-09 16:19 ` [PATCH 07/16] dma-debug: add debugfs interface Joerg Roedel
2009-01-10 23:08 ` Ingo Molnar
2009-01-11 7:52 ` Joerg Roedel
2009-01-14 15:22 ` Joerg Roedel
2009-01-10 23:15 ` Ingo Molnar
2009-01-09 16:19 ` [PATCH 08/16] dma-debug: add core checking functions Joerg Roedel
2009-01-10 23:11 ` Ingo Molnar
2009-01-11 7:57 ` Joerg Roedel
2009-01-11 8:34 ` Joerg Roedel
2009-01-14 11:44 ` Joerg Roedel
2009-01-14 11:48 ` Ingo Molnar
2009-01-10 23:12 ` Ingo Molnar
2009-01-11 7:54 ` Joerg Roedel
2009-01-10 23:13 ` Ingo Molnar
2009-01-09 16:19 ` [PATCH 09/16] dma-debug: add checking for map/unmap_single Joerg Roedel
2009-01-09 16:19 ` [PATCH 10/16] dma-debug: add add checking for map/unmap_sg Joerg Roedel
2009-01-09 18:08 ` Evgeniy Polyakov
2009-01-09 18:11 ` Joerg Roedel
2009-01-09 16:19 ` [PATCH 11/16] dma-debug: add checking for [alloc|free]_coherent Joerg Roedel
2009-01-11 6:25 ` FUJITA Tomonori
2009-01-11 6:30 ` FUJITA Tomonori
2009-01-11 7:59 ` Joerg Roedel
2009-01-09 16:19 ` [PATCH 12/16] dma-debug: add checks for sync_single_* Joerg Roedel
2009-01-09 16:19 ` [PATCH 13/16] dma-debug: add checks for sync_single_range_* Joerg Roedel
2009-01-09 16:19 ` [PATCH 14/16] dma-debug: add checks for sync_single_sg_* Joerg Roedel
2009-01-10 23:46 ` Ingo Molnar
2009-01-11 8:00 ` Joerg Roedel
2009-01-09 16:19 ` [PATCH 15/16] dma-debug: x86 architecture bindings Joerg Roedel
2009-01-10 23:04 ` Ingo Molnar
2009-01-10 23:48 ` Ingo Molnar
2009-01-11 6:25 ` FUJITA Tomonori
2009-01-11 8:08 ` Joerg Roedel
2009-01-09 16:19 ` [PATCH 16/16] dma-debug: Documentation update Joerg Roedel
2009-01-09 21:24 ` [PATCH 0/16] DMA-API debugging facility v2 Michael Chan
2009-01-09 22:33 ` Joerg Roedel
2009-01-09 22:37 ` Joerg Roedel
2009-01-11 6:25 ` FUJITA Tomonori
2009-01-10 23:54 ` Ingo Molnar
2009-01-11 8:11 ` Joerg Roedel
2009-02-05 22:52 ` David Woodhouse
2009-02-06 2:05 ` Chris Wright
2009-02-06 7:56 ` David Woodhouse
2009-02-06 16:08 ` Chris Wright
2009-02-06 18:20 ` Chris Wright
2009-02-12 14:48 ` Joerg Roedel
2009-02-06 2:27 ` Chris Wright
2009-02-12 15:20 ` Joerg Roedel
2009-01-19 14:46 [PATCH 0/16] DMA-API debugging facility v3 Joerg Roedel
2009-01-19 14:46 ` [PATCH 03/16] dma-debug: add hash functions for dma_debug_entries Joerg Roedel
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1231517970-20288-4-git-send-email-joerg.roedel@amd.com \
--to=joerg.roedel@amd.com \
--cc=dwmw2@infradead.org \
--cc=fujita.tomonori@lab.ntt.co.jp \
--cc=iommu@lists.linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=netdev@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).