2012-11-03 23:00:15

by Shuah Khan

[permalink] [raw]
Subject: [PATCH] dma-debug: fix to not have dependency on get_dma_ops() interface

dma-debug depends on get_dma_ops() interface. Several architectures
do not define dma_ops and get_dma_ops(). When dma debug interfaces are
used on an architecture (e.g: c6x) that doesn't define get_dmap_ops(),
compilation fails. Changing dma-debug to call dma_mapping_error() instead
of defining its own that calls get_dma_ops(), such that the internal use of
dma_mapping_error() doesn't interfere with the debug_dma_mapping_error()
interface's mapping error checks. Moving dma_mapping_error() checks in
check_unmap() under the dma debug entry not found is sufficient to fix the
problem.

Reference: https://lkml.org/lkml/2012/10/26/367

Signed-off-by: Shuah Khan <[email protected]>
Reported-by: Mark Salter <[email protected]>
---
lib/dma-debug.c | 29 +++++++----------------------
1 file changed, 7 insertions(+), 22 deletions(-)

diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index 59f4a1a..5e396ac 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -852,37 +852,22 @@ static __init int dma_debug_entries_cmdline(char *str)
__setup("dma_debug=", dma_debug_cmdline);
__setup("dma_debug_entries=", dma_debug_entries_cmdline);

-/* Calling dma_mapping_error() from dma-debug api will result in calling
- debug_dma_mapping_error() - need internal mapping error routine to
- avoid debug checks */
-#ifndef DMA_ERROR_CODE
-#define DMA_ERROR_CODE 0
-#endif
-static inline int has_mapping_error(struct device *dev, dma_addr_t dma_addr)
-{
- const struct dma_map_ops *ops = get_dma_ops(dev);
- if (ops->mapping_error)
- return ops->mapping_error(dev, dma_addr);
-
- return (dma_addr == DMA_ERROR_CODE);
-}
-
static void check_unmap(struct dma_debug_entry *ref)
{
struct dma_debug_entry *entry;
struct hash_bucket *bucket;
unsigned long flags;

- if (unlikely(has_mapping_error(ref->dev, ref->dev_addr))) {
- err_printk(ref->dev, NULL, "DMA-API: device driver tries "
- "to free an invalid DMA memory address\n");
- return;
- }
-
bucket = get_hash_bucket(ref, &flags);
entry = bucket_find_exact(bucket, ref);

if (!entry) {
+ if (dma_mapping_error(ref->dev, ref->dev_addr)) {
+ err_printk(ref->dev, NULL,
+ "DMA-API: device driver tries "
+ "to free an invalid DMA memory address\n");
+ return;
+ }
err_printk(ref->dev, NULL, "DMA-API: device driver tries "
"to free DMA memory it has not allocated "
"[device address=0x%016llx] [size=%llu bytes]\n",
@@ -1055,7 +1040,7 @@ void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
if (unlikely(global_disable))
return;

- if (unlikely(has_mapping_error(dev, dma_addr)))
+ if (dma_mapping_error(dev, dma_addr))
return;

entry = dma_entry_alloc();
--
1.7.9.5



2012-11-05 14:12:30

by Konrad Rzeszutek Wilk

[permalink] [raw]
Subject: Re: [PATCH] dma-debug: fix to not have dependency on get_dma_ops() interface

On Sat, Nov 03, 2012 at 05:00:07PM -0600, Shuah Khan wrote:
> dma-debug depends on get_dma_ops() interface. Several architectures
> do not define dma_ops and get_dma_ops(). When dma debug interfaces are
> used on an architecture (e.g: c6x) that doesn't define get_dmap_ops(),
> compilation fails. Changing dma-debug to call dma_mapping_error() instead
> of defining its own that calls get_dma_ops(), such that the internal use of
> dma_mapping_error() doesn't interfere with the debug_dma_mapping_error()
> interface's mapping error checks. Moving dma_mapping_error() checks in
> check_unmap() under the dma debug entry not found is sufficient to fix the
> problem.

OK.

It looks ok to me.

> - debug_dma_mapping_error() - need internal mapping error routine to
> - avoid debug checks */
> -#ifndef DMA_ERROR_CODE
> -#define DMA_ERROR_CODE 0
> -#endif
> -static inline int has_mapping_error(struct device *dev, dma_addr_t dma_addr)
> -{
> - const struct dma_map_ops *ops = get_dma_ops(dev);
> - if (ops->mapping_error)
> - return ops->mapping_error(dev, dma_addr);
> -
> - return (dma_addr == DMA_ERROR_CODE);
> -}
> -
> static void check_unmap(struct dma_debug_entry *ref)
> {
> struct dma_debug_entry *entry;
> struct hash_bucket *bucket;
> unsigned long flags;
>
> - if (unlikely(has_mapping_error(ref->dev, ref->dev_addr))) {
> - err_printk(ref->dev, NULL, "DMA-API: device driver tries "
> - "to free an invalid DMA memory address\n");
> - return;
> - }
> -
> bucket = get_hash_bucket(ref, &flags);
> entry = bucket_find_exact(bucket, ref);
>
> if (!entry) {
> + if (dma_mapping_error(ref->dev, ref->dev_addr)) {
> + err_printk(ref->dev, NULL,
> + "DMA-API: device driver tries "
> + "to free an invalid DMA memory address\n");
> + return;
> + }
> err_printk(ref->dev, NULL, "DMA-API: device driver tries "
> "to free DMA memory it has not allocated "
> "[device address=0x%016llx] [size=%llu bytes]\n",
> @@ -1055,7 +1040,7 @@ void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
> if (unlikely(global_disable))
> return;
>
> - if (unlikely(has_mapping_error(dev, dma_addr)))
> + if (dma_mapping_error(dev, dma_addr))
> return;
>
> entry = dma_entry_alloc();
> --
> 1.7.9.5
>
>

2012-11-15 17:04:31

by Shuah Khan

[permalink] [raw]
Subject: Re: [PATCH] dma-debug: fix to not have dependency on get_dma_ops() interface

On Mon, 2012-11-05 at 08:59 -0500, Konrad Rzeszutek Wilk wrote:
> On Sat, Nov 03, 2012 at 05:00:07PM -0600, Shuah Khan wrote:
> > dma-debug depends on get_dma_ops() interface. Several architectures
> > do not define dma_ops and get_dma_ops(). When dma debug interfaces are
> > used on an architecture (e.g: c6x) that doesn't define get_dmap_ops(),
> > compilation fails. Changing dma-debug to call dma_mapping_error() instead
> > of defining its own that calls get_dma_ops(), such that the internal use of
> > dma_mapping_error() doesn't interfere with the debug_dma_mapping_error()
> > interface's mapping error checks. Moving dma_mapping_error() checks in
> > check_unmap() under the dma debug entry not found is sufficient to fix the
> > problem.
>
> OK.
>
> It looks ok to me.

Marek,

Following up on our off-line discussion about your offer to pull
dma-debug patch and the arch patches that call debug_dma_mapping_error()
interface in to your tree. Thanks again for offering to do that. This
patch is depends on the first debug_dma_mapping_error() patch that is in
linux-next and in the dma-debug tree.

Reference - https://lkml.org/lkml/2012/10/8/296

linux-next commit-id is commit 6c9c6d6301287e369a754d628230fa6e50cdb74b

You will need to pull these two first into your tree and then the arch
patches - I will include you on my responses to those patches shortly.

-- Shuah

>
> > - debug_dma_mapping_error() - need internal mapping error routine to
> > - avoid debug checks */
> > -#ifndef DMA_ERROR_CODE
> > -#define DMA_ERROR_CODE 0
> > -#endif
> > -static inline int has_mapping_error(struct device *dev, dma_addr_t dma_addr)
> > -{
> > - const struct dma_map_ops *ops = get_dma_ops(dev);
> > - if (ops->mapping_error)
> > - return ops->mapping_error(dev, dma_addr);
> > -
> > - return (dma_addr == DMA_ERROR_CODE);
> > -}
> > -
> > static void check_unmap(struct dma_debug_entry *ref)
> > {
> > struct dma_debug_entry *entry;
> > struct hash_bucket *bucket;
> > unsigned long flags;
> >
> > - if (unlikely(has_mapping_error(ref->dev, ref->dev_addr))) {
> > - err_printk(ref->dev, NULL, "DMA-API: device driver tries "
> > - "to free an invalid DMA memory address\n");
> > - return;
> > - }
> > -
> > bucket = get_hash_bucket(ref, &flags);
> > entry = bucket_find_exact(bucket, ref);
> >
> > if (!entry) {
> > + if (dma_mapping_error(ref->dev, ref->dev_addr)) {
> > + err_printk(ref->dev, NULL,
> > + "DMA-API: device driver tries "
> > + "to free an invalid DMA memory address\n");
> > + return;
> > + }
> > err_printk(ref->dev, NULL, "DMA-API: device driver tries "
> > "to free DMA memory it has not allocated "
> > "[device address=0x%016llx] [size=%llu bytes]\n",
> > @@ -1055,7 +1040,7 @@ void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
> > if (unlikely(global_disable))
> > return;
> >
> > - if (unlikely(has_mapping_error(dev, dma_addr)))
> > + if (dma_mapping_error(dev, dma_addr))
> > return;
> >
> > entry = dma_entry_alloc();
> > --
> > 1.7.9.5
> >
> >

2012-11-17 12:07:30

by Joerg Roedel

[permalink] [raw]
Subject: Re: [PATCH] dma-debug: fix to not have dependency on get_dma_ops() interface

On Sat, Nov 03, 2012 at 05:00:07PM -0600, Shuah Khan wrote:
> dma-debug depends on get_dma_ops() interface. Several architectures
> do not define dma_ops and get_dma_ops(). When dma debug interfaces are
> used on an architecture (e.g: c6x) that doesn't define get_dmap_ops(),
> compilation fails. Changing dma-debug to call dma_mapping_error() instead
> of defining its own that calls get_dma_ops(), such that the internal use of
> dma_mapping_error() doesn't interfere with the debug_dma_mapping_error()
> interface's mapping error checks. Moving dma_mapping_error() checks in
> check_unmap() under the dma debug entry not found is sufficient to fix the
> problem.
>
> Reference: https://lkml.org/lkml/2012/10/26/367
>
> Signed-off-by: Shuah Khan <[email protected]>
> Reported-by: Mark Salter <[email protected]>

Sorry for the delay. I applied the patch to the dma-debug branch.


Joerg