Add dma-debug interface debug_dma_mapping_error() to debug drivers that fail
to check dma mapping errors on addresses returned by dma_map_single() and
dma_map_page() interfaces. This interface clears a flag set by
debug_dma_map_page() to indicate that dma_mapping_error() has been called by
the driver. When driver does unmap, debug_dma_unmap() checks the flag and if
this flag is still set, prints warning message that includes call trace that
leads up to the unmap. This interface can be called from dma_mapping_error()
routines to enable dma mapping error check debugging.
Tested: Intel iommu and swiotlb (iommu=soft) on x86-64 with
CONFIG_DMA_API_DEBUG enabled and disabled.
Signed-off-by: Shuah Khan <[email protected]>
---
Documentation/DMA-API.txt | 12 ++++++
arch/x86/include/asm/dma-mapping.h | 1 +
include/linux/dma-debug.h | 7 ++++
lib/dma-debug.c | 71 ++++++++++++++++++++++++++++++++++--
4 files changed, 87 insertions(+), 4 deletions(-)
diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt
index 66bd97a..78a6c56 100644
--- a/Documentation/DMA-API.txt
+++ b/Documentation/DMA-API.txt
@@ -678,3 +678,15 @@ out of dma_debug_entries. These entries are preallocated at boot. The number
of preallocated entries is defined per architecture. If it is too low for you
boot with 'dma_debug_entries=<your_desired_number>' to overwrite the
architectural default.
+
+void debug_dmap_mapping_error(struct device *dev, dma_addr_t dma_addr);
+
+dma-debug interface debug_dma_mapping_error() to debug drivers that fail
+to check dma mapping errors on addresses returned by dma_map_single() and
+dma_map_page() interfaces. This interface clears a flag set by
+debug_dma_map_page() to indicate that dma_mapping_error() has been called by
+the driver. When driver does unmap, debug_dma_unmap() checks the flag and if
+this flag is still set, prints warning message that includes call trace that
+leads up to the unmap. This interface can be called from dma_mapping_error()
+routines to enable dma mapping error check debugging.
+
diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/asm/dma-mapping.h
index f7b4c79..808dae6 100644
--- a/arch/x86/include/asm/dma-mapping.h
+++ b/arch/x86/include/asm/dma-mapping.h
@@ -47,6 +47,7 @@ static inline struct dma_map_ops *get_dma_ops(struct device *dev)
static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
{
struct dma_map_ops *ops = get_dma_ops(dev);
+ debug_dma_mapping_error(dev, dma_addr);
if (ops->mapping_error)
return ops->mapping_error(dev, dma_addr);
diff --git a/include/linux/dma-debug.h b/include/linux/dma-debug.h
index 171ad8a..fc0e34c 100644
--- a/include/linux/dma-debug.h
+++ b/include/linux/dma-debug.h
@@ -39,6 +39,8 @@ extern void debug_dma_map_page(struct device *dev, struct page *page,
int direction, dma_addr_t dma_addr,
bool map_single);
+extern void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr);
+
extern void debug_dma_unmap_page(struct device *dev, dma_addr_t addr,
size_t size, int direction, bool map_single);
@@ -105,6 +107,11 @@ static inline void debug_dma_map_page(struct device *dev, struct page *page,
{
}
+static inline void debug_dma_mapping_error(struct device *dev,
+ dma_addr_t dma_addr)
+{
+}
+
static inline void debug_dma_unmap_page(struct device *dev, dma_addr_t addr,
size_t size, int direction,
bool map_single)
diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index b9087bf..94aa94e 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -45,6 +45,12 @@ enum {
dma_debug_coherent,
};
+enum map_err_types {
+ MAP_ERR_CHECK_NOT_APPLICABLE,
+ MAP_ERR_NOT_CHECKED,
+ MAP_ERR_CHECKED,
+};
+
#define DMA_DEBUG_STACKTRACE_ENTRIES 5
struct dma_debug_entry {
@@ -57,6 +63,7 @@ struct dma_debug_entry {
int direction;
int sg_call_ents;
int sg_mapped_ents;
+ enum map_err_types map_err_type;
#ifdef CONFIG_STACKTRACE
struct stack_trace stacktrace;
unsigned long st_entries[DMA_DEBUG_STACKTRACE_ENTRIES];
@@ -114,6 +121,12 @@ static struct device_driver *current_driver __read_mostly;
static DEFINE_RWLOCK(driver_name_lock);
+static const char *const maperr2str[] = {
+ [MAP_ERR_CHECK_NOT_APPLICABLE] = "dma map error check not applicable",
+ [MAP_ERR_NOT_CHECKED] = "dma map error not checked",
+ [MAP_ERR_CHECKED] = "dma map error checked",
+};
+
static const char *type2name[4] = { "single", "page",
"scather-gather", "coherent" };
@@ -376,11 +389,12 @@ void debug_dma_dump_mappings(struct device *dev)
list_for_each_entry(entry, &bucket->list, list) {
if (!dev || dev == entry->dev) {
dev_info(entry->dev,
- "%s idx %d P=%Lx D=%Lx L=%Lx %s\n",
+ "%s idx %d P=%Lx D=%Lx L=%Lx %s %s\n",
type2name[entry->type], idx,
(unsigned long long)entry->paddr,
entry->dev_addr, entry->size,
- dir2name[entry->direction]);
+ dir2name[entry->direction],
+ maperr2str[entry->map_err_type]);
}
}
@@ -838,13 +852,28 @@ 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 (dma_mapping_error(ref->dev, ref->dev_addr)) {
+ 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;
@@ -910,6 +939,15 @@ static void check_unmap(struct dma_debug_entry *ref)
dir2name[ref->direction]);
}
+ if (entry->map_err_type == MAP_ERR_NOT_CHECKED) {
+ err_printk(ref->dev, entry,
+ "DMA-API: device driver failed to check map error"
+ "[device address=0x%016llx] [size=%llu bytes] "
+ "[mapped as %s]",
+ ref->dev_addr, ref->size,
+ type2name[entry->type]);
+ }
+
hash_bucket_del(entry);
dma_entry_free(entry);
@@ -1017,7 +1055,7 @@ void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
if (unlikely(global_disable))
return;
- if (unlikely(dma_mapping_error(dev, dma_addr)))
+ if (unlikely(has_mapping_error(dev, dma_addr)))
return;
entry = dma_entry_alloc();
@@ -1030,6 +1068,7 @@ void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
entry->dev_addr = dma_addr;
entry->size = size;
entry->direction = direction;
+ entry->map_err_type = MAP_ERR_NOT_CHECKED;
if (map_single)
entry->type = dma_debug_single;
@@ -1045,6 +1084,30 @@ void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
}
EXPORT_SYMBOL(debug_dma_map_page);
+void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
+{
+ struct dma_debug_entry ref;
+ struct dma_debug_entry *entry;
+ struct hash_bucket *bucket;
+ unsigned long flags;
+
+ if (unlikely(global_disable))
+ return;
+
+ ref.dev = dev;
+ ref.dev_addr = dma_addr;
+ bucket = get_hash_bucket(&ref, &flags);
+ entry = bucket_find_exact(bucket, &ref);
+
+ if (!entry)
+ goto out;
+
+ entry->map_err_type = MAP_ERR_CHECKED;
+out:
+ put_hash_bucket(bucket, &flags);
+}
+EXPORT_SYMBOL(debug_dma_mapping_error);
+
void debug_dma_unmap_page(struct device *dev, dma_addr_t addr,
size_t size, int direction, bool map_single)
{
--
1.7.9.5
On Mon, Oct 08, 2012 at 11:08:06AM -0600, Shuah Khan wrote:
> Add dma-debug interface debug_dma_mapping_error() to debug drivers that fail
> to check dma mapping errors on addresses returned by dma_map_single() and
> dma_map_page() interfaces. This interface clears a flag set by
> debug_dma_map_page() to indicate that dma_mapping_error() has been called by
> the driver. When driver does unmap, debug_dma_unmap() checks the flag and if
> this flag is still set, prints warning message that includes call trace that
> leads up to the unmap. This interface can be called from dma_mapping_error()
> routines to enable dma mapping error check debugging.
>
> Tested: Intel iommu and swiotlb (iommu=soft) on x86-64 with
> CONFIG_DMA_API_DEBUG enabled and disabled.
>
> Signed-off-by: Shuah Khan <[email protected]>
Not sure why it disappeared, but:
Reviewed-by: Konrad Rzeszutek Wilk <[email protected]>
> ---
> Documentation/DMA-API.txt | 12 ++++++
> arch/x86/include/asm/dma-mapping.h | 1 +
> include/linux/dma-debug.h | 7 ++++
> lib/dma-debug.c | 71 ++++++++++++++++++++++++++++++++++--
> 4 files changed, 87 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt
> index 66bd97a..78a6c56 100644
> --- a/Documentation/DMA-API.txt
> +++ b/Documentation/DMA-API.txt
> @@ -678,3 +678,15 @@ out of dma_debug_entries. These entries are preallocated at boot. The number
> of preallocated entries is defined per architecture. If it is too low for you
> boot with 'dma_debug_entries=<your_desired_number>' to overwrite the
> architectural default.
> +
> +void debug_dmap_mapping_error(struct device *dev, dma_addr_t dma_addr);
> +
> +dma-debug interface debug_dma_mapping_error() to debug drivers that fail
> +to check dma mapping errors on addresses returned by dma_map_single() and
> +dma_map_page() interfaces. This interface clears a flag set by
> +debug_dma_map_page() to indicate that dma_mapping_error() has been called by
> +the driver. When driver does unmap, debug_dma_unmap() checks the flag and if
> +this flag is still set, prints warning message that includes call trace that
> +leads up to the unmap. This interface can be called from dma_mapping_error()
> +routines to enable dma mapping error check debugging.
> +
> diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/asm/dma-mapping.h
> index f7b4c79..808dae6 100644
> --- a/arch/x86/include/asm/dma-mapping.h
> +++ b/arch/x86/include/asm/dma-mapping.h
> @@ -47,6 +47,7 @@ static inline struct dma_map_ops *get_dma_ops(struct device *dev)
> static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
> {
> struct dma_map_ops *ops = get_dma_ops(dev);
> + debug_dma_mapping_error(dev, dma_addr);
> if (ops->mapping_error)
> return ops->mapping_error(dev, dma_addr);
>
> diff --git a/include/linux/dma-debug.h b/include/linux/dma-debug.h
> index 171ad8a..fc0e34c 100644
> --- a/include/linux/dma-debug.h
> +++ b/include/linux/dma-debug.h
> @@ -39,6 +39,8 @@ extern void debug_dma_map_page(struct device *dev, struct page *page,
> int direction, dma_addr_t dma_addr,
> bool map_single);
>
> +extern void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr);
> +
> extern void debug_dma_unmap_page(struct device *dev, dma_addr_t addr,
> size_t size, int direction, bool map_single);
>
> @@ -105,6 +107,11 @@ static inline void debug_dma_map_page(struct device *dev, struct page *page,
> {
> }
>
> +static inline void debug_dma_mapping_error(struct device *dev,
> + dma_addr_t dma_addr)
> +{
> +}
> +
> static inline void debug_dma_unmap_page(struct device *dev, dma_addr_t addr,
> size_t size, int direction,
> bool map_single)
> diff --git a/lib/dma-debug.c b/lib/dma-debug.c
> index b9087bf..94aa94e 100644
> --- a/lib/dma-debug.c
> +++ b/lib/dma-debug.c
> @@ -45,6 +45,12 @@ enum {
> dma_debug_coherent,
> };
>
> +enum map_err_types {
> + MAP_ERR_CHECK_NOT_APPLICABLE,
> + MAP_ERR_NOT_CHECKED,
> + MAP_ERR_CHECKED,
> +};
> +
> #define DMA_DEBUG_STACKTRACE_ENTRIES 5
>
> struct dma_debug_entry {
> @@ -57,6 +63,7 @@ struct dma_debug_entry {
> int direction;
> int sg_call_ents;
> int sg_mapped_ents;
> + enum map_err_types map_err_type;
> #ifdef CONFIG_STACKTRACE
> struct stack_trace stacktrace;
> unsigned long st_entries[DMA_DEBUG_STACKTRACE_ENTRIES];
> @@ -114,6 +121,12 @@ static struct device_driver *current_driver __read_mostly;
>
> static DEFINE_RWLOCK(driver_name_lock);
>
> +static const char *const maperr2str[] = {
> + [MAP_ERR_CHECK_NOT_APPLICABLE] = "dma map error check not applicable",
> + [MAP_ERR_NOT_CHECKED] = "dma map error not checked",
> + [MAP_ERR_CHECKED] = "dma map error checked",
> +};
> +
> static const char *type2name[4] = { "single", "page",
> "scather-gather", "coherent" };
>
> @@ -376,11 +389,12 @@ void debug_dma_dump_mappings(struct device *dev)
> list_for_each_entry(entry, &bucket->list, list) {
> if (!dev || dev == entry->dev) {
> dev_info(entry->dev,
> - "%s idx %d P=%Lx D=%Lx L=%Lx %s\n",
> + "%s idx %d P=%Lx D=%Lx L=%Lx %s %s\n",
> type2name[entry->type], idx,
> (unsigned long long)entry->paddr,
> entry->dev_addr, entry->size,
> - dir2name[entry->direction]);
> + dir2name[entry->direction],
> + maperr2str[entry->map_err_type]);
> }
> }
>
> @@ -838,13 +852,28 @@ 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 (dma_mapping_error(ref->dev, ref->dev_addr)) {
> + 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;
> @@ -910,6 +939,15 @@ static void check_unmap(struct dma_debug_entry *ref)
> dir2name[ref->direction]);
> }
>
> + if (entry->map_err_type == MAP_ERR_NOT_CHECKED) {
> + err_printk(ref->dev, entry,
> + "DMA-API: device driver failed to check map error"
> + "[device address=0x%016llx] [size=%llu bytes] "
> + "[mapped as %s]",
> + ref->dev_addr, ref->size,
> + type2name[entry->type]);
> + }
> +
> hash_bucket_del(entry);
> dma_entry_free(entry);
>
> @@ -1017,7 +1055,7 @@ void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
> if (unlikely(global_disable))
> return;
>
> - if (unlikely(dma_mapping_error(dev, dma_addr)))
> + if (unlikely(has_mapping_error(dev, dma_addr)))
> return;
>
> entry = dma_entry_alloc();
> @@ -1030,6 +1068,7 @@ void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
> entry->dev_addr = dma_addr;
> entry->size = size;
> entry->direction = direction;
> + entry->map_err_type = MAP_ERR_NOT_CHECKED;
>
> if (map_single)
> entry->type = dma_debug_single;
> @@ -1045,6 +1084,30 @@ void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
> }
> EXPORT_SYMBOL(debug_dma_map_page);
>
> +void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
> +{
> + struct dma_debug_entry ref;
> + struct dma_debug_entry *entry;
> + struct hash_bucket *bucket;
> + unsigned long flags;
> +
> + if (unlikely(global_disable))
> + return;
> +
> + ref.dev = dev;
> + ref.dev_addr = dma_addr;
> + bucket = get_hash_bucket(&ref, &flags);
> + entry = bucket_find_exact(bucket, &ref);
> +
> + if (!entry)
> + goto out;
> +
> + entry->map_err_type = MAP_ERR_CHECKED;
> +out:
> + put_hash_bucket(bucket, &flags);
> +}
> +EXPORT_SYMBOL(debug_dma_mapping_error);
> +
> void debug_dma_unmap_page(struct device *dev, dma_addr_t addr,
> size_t size, int direction, bool map_single)
> {
> --
> 1.7.9.5
>
>
On Tue, 2012-10-09 at 13:12 -0400, Konrad Rzeszutek Wilk wrote:
> On Mon, Oct 08, 2012 at 11:08:06AM -0600, Shuah Khan wrote:
> > Add dma-debug interface debug_dma_mapping_error() to debug drivers that fail
> > to check dma mapping errors on addresses returned by dma_map_single() and
> > dma_map_page() interfaces. This interface clears a flag set by
> > debug_dma_map_page() to indicate that dma_mapping_error() has been called by
> > the driver. When driver does unmap, debug_dma_unmap() checks the flag and if
> > this flag is still set, prints warning message that includes call trace that
> > leads up to the unmap. This interface can be called from dma_mapping_error()
> > routines to enable dma mapping error check debugging.
> >
> > Tested: Intel iommu and swiotlb (iommu=soft) on x86-64 with
> > CONFIG_DMA_API_DEBUG enabled and disabled.
> >
> > Signed-off-by: Shuah Khan <[email protected]>
>
> Not sure why it disappeared, but:
>
> Reviewed-by: Konrad Rzeszutek Wilk <[email protected]>
Sorry, my bad. Thanks.
> > ---
> > Documentation/DMA-API.txt | 12 ++++++
> > arch/x86/include/asm/dma-mapping.h | 1 +
> > include/linux/dma-debug.h | 7 ++++
> > lib/dma-debug.c | 71 ++++++++++++++++++++++++++++++++++--
> > 4 files changed, 87 insertions(+), 4 deletions(-)
> >
> > diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt
> > index 66bd97a..78a6c56 100644
> > --- a/Documentation/DMA-API.txt
> > +++ b/Documentation/DMA-API.txt
> > @@ -678,3 +678,15 @@ out of dma_debug_entries. These entries are preallocated at boot. The number
> > of preallocated entries is defined per architecture. If it is too low for you
> > boot with 'dma_debug_entries=<your_desired_number>' to overwrite the
> > architectural default.
> > +
> > +void debug_dmap_mapping_error(struct device *dev, dma_addr_t dma_addr);
> > +
> > +dma-debug interface debug_dma_mapping_error() to debug drivers that fail
> > +to check dma mapping errors on addresses returned by dma_map_single() and
> > +dma_map_page() interfaces. This interface clears a flag set by
> > +debug_dma_map_page() to indicate that dma_mapping_error() has been called by
> > +the driver. When driver does unmap, debug_dma_unmap() checks the flag and if
> > +this flag is still set, prints warning message that includes call trace that
> > +leads up to the unmap. This interface can be called from dma_mapping_error()
> > +routines to enable dma mapping error check debugging.
> > +
> > diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/asm/dma-mapping.h
> > index f7b4c79..808dae6 100644
> > --- a/arch/x86/include/asm/dma-mapping.h
> > +++ b/arch/x86/include/asm/dma-mapping.h
> > @@ -47,6 +47,7 @@ static inline struct dma_map_ops *get_dma_ops(struct device *dev)
> > static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
> > {
> > struct dma_map_ops *ops = get_dma_ops(dev);
> > + debug_dma_mapping_error(dev, dma_addr);
> > if (ops->mapping_error)
> > return ops->mapping_error(dev, dma_addr);
> >
> > diff --git a/include/linux/dma-debug.h b/include/linux/dma-debug.h
> > index 171ad8a..fc0e34c 100644
> > --- a/include/linux/dma-debug.h
> > +++ b/include/linux/dma-debug.h
> > @@ -39,6 +39,8 @@ extern void debug_dma_map_page(struct device *dev, struct page *page,
> > int direction, dma_addr_t dma_addr,
> > bool map_single);
> >
> > +extern void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr);
> > +
> > extern void debug_dma_unmap_page(struct device *dev, dma_addr_t addr,
> > size_t size, int direction, bool map_single);
> >
> > @@ -105,6 +107,11 @@ static inline void debug_dma_map_page(struct device *dev, struct page *page,
> > {
> > }
> >
> > +static inline void debug_dma_mapping_error(struct device *dev,
> > + dma_addr_t dma_addr)
> > +{
> > +}
> > +
> > static inline void debug_dma_unmap_page(struct device *dev, dma_addr_t addr,
> > size_t size, int direction,
> > bool map_single)
> > diff --git a/lib/dma-debug.c b/lib/dma-debug.c
> > index b9087bf..94aa94e 100644
> > --- a/lib/dma-debug.c
> > +++ b/lib/dma-debug.c
> > @@ -45,6 +45,12 @@ enum {
> > dma_debug_coherent,
> > };
> >
> > +enum map_err_types {
> > + MAP_ERR_CHECK_NOT_APPLICABLE,
> > + MAP_ERR_NOT_CHECKED,
> > + MAP_ERR_CHECKED,
> > +};
> > +
> > #define DMA_DEBUG_STACKTRACE_ENTRIES 5
> >
> > struct dma_debug_entry {
> > @@ -57,6 +63,7 @@ struct dma_debug_entry {
> > int direction;
> > int sg_call_ents;
> > int sg_mapped_ents;
> > + enum map_err_types map_err_type;
> > #ifdef CONFIG_STACKTRACE
> > struct stack_trace stacktrace;
> > unsigned long st_entries[DMA_DEBUG_STACKTRACE_ENTRIES];
> > @@ -114,6 +121,12 @@ static struct device_driver *current_driver __read_mostly;
> >
> > static DEFINE_RWLOCK(driver_name_lock);
> >
> > +static const char *const maperr2str[] = {
> > + [MAP_ERR_CHECK_NOT_APPLICABLE] = "dma map error check not applicable",
> > + [MAP_ERR_NOT_CHECKED] = "dma map error not checked",
> > + [MAP_ERR_CHECKED] = "dma map error checked",
> > +};
> > +
> > static const char *type2name[4] = { "single", "page",
> > "scather-gather", "coherent" };
> >
> > @@ -376,11 +389,12 @@ void debug_dma_dump_mappings(struct device *dev)
> > list_for_each_entry(entry, &bucket->list, list) {
> > if (!dev || dev == entry->dev) {
> > dev_info(entry->dev,
> > - "%s idx %d P=%Lx D=%Lx L=%Lx %s\n",
> > + "%s idx %d P=%Lx D=%Lx L=%Lx %s %s\n",
> > type2name[entry->type], idx,
> > (unsigned long long)entry->paddr,
> > entry->dev_addr, entry->size,
> > - dir2name[entry->direction]);
> > + dir2name[entry->direction],
> > + maperr2str[entry->map_err_type]);
> > }
> > }
> >
> > @@ -838,13 +852,28 @@ 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 (dma_mapping_error(ref->dev, ref->dev_addr)) {
> > + 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;
> > @@ -910,6 +939,15 @@ static void check_unmap(struct dma_debug_entry *ref)
> > dir2name[ref->direction]);
> > }
> >
> > + if (entry->map_err_type == MAP_ERR_NOT_CHECKED) {
> > + err_printk(ref->dev, entry,
> > + "DMA-API: device driver failed to check map error"
> > + "[device address=0x%016llx] [size=%llu bytes] "
> > + "[mapped as %s]",
> > + ref->dev_addr, ref->size,
> > + type2name[entry->type]);
> > + }
> > +
> > hash_bucket_del(entry);
> > dma_entry_free(entry);
> >
> > @@ -1017,7 +1055,7 @@ void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
> > if (unlikely(global_disable))
> > return;
> >
> > - if (unlikely(dma_mapping_error(dev, dma_addr)))
> > + if (unlikely(has_mapping_error(dev, dma_addr)))
> > return;
> >
> > entry = dma_entry_alloc();
> > @@ -1030,6 +1068,7 @@ void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
> > entry->dev_addr = dma_addr;
> > entry->size = size;
> > entry->direction = direction;
> > + entry->map_err_type = MAP_ERR_NOT_CHECKED;
> >
> > if (map_single)
> > entry->type = dma_debug_single;
> > @@ -1045,6 +1084,30 @@ void debug_dma_map_page(struct device *dev, struct page *page, size_t offset,
> > }
> > EXPORT_SYMBOL(debug_dma_map_page);
> >
> > +void debug_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
> > +{
> > + struct dma_debug_entry ref;
> > + struct dma_debug_entry *entry;
> > + struct hash_bucket *bucket;
> > + unsigned long flags;
> > +
> > + if (unlikely(global_disable))
> > + return;
> > +
> > + ref.dev = dev;
> > + ref.dev_addr = dma_addr;
> > + bucket = get_hash_bucket(&ref, &flags);
> > + entry = bucket_find_exact(bucket, &ref);
> > +
> > + if (!entry)
> > + goto out;
> > +
> > + entry->map_err_type = MAP_ERR_CHECKED;
> > +out:
> > + put_hash_bucket(bucket, &flags);
> > +}
> > +EXPORT_SYMBOL(debug_dma_mapping_error);
> > +
> > void debug_dma_unmap_page(struct device *dev, dma_addr_t addr,
> > size_t size, int direction, bool map_single)
> > {
> > --
> > 1.7.9.5
> >
> >
On Mon, 08 Oct 2012 11:08:06 -0600
Shuah Khan <[email protected]> wrote:
> Add dma-debug interface debug_dma_mapping_error() to debug drivers that fail
> to check dma mapping errors on addresses returned by dma_map_single() and
> dma_map_page() interfaces. This interface clears a flag set by
> debug_dma_map_page() to indicate that dma_mapping_error() has been called by
> the driver. When driver does unmap, debug_dma_unmap() checks the flag and if
> this flag is still set, prints warning message that includes call trace that
> leads up to the unmap. This interface can be called from dma_mapping_error()
> routines to enable dma mapping error check debugging.
>
> Tested: Intel iommu and swiotlb (iommu=soft) on x86-64 with
> CONFIG_DMA_API_DEBUG enabled and disabled.
>
> Signed-off-by: Shuah Khan <[email protected]>
> ---
> Documentation/DMA-API.txt | 12 ++++++
> arch/x86/include/asm/dma-mapping.h | 1 +
> include/linux/dma-debug.h | 7 ++++
> lib/dma-debug.c | 71 ++++++++++++++++++++++++++++++++++--
Third time lucky ... we still haven't fixed Documentation/DMA-API-HOWTO.txt!
Please, go through it and update it to show people how to correctly use
these APIs.
On Tue, 2012-10-09 at 14:06 -0700, Andrew Morton wrote:
> On Mon, 08 Oct 2012 11:08:06 -0600
> Shuah Khan <[email protected]> wrote:
>
> > Add dma-debug interface debug_dma_mapping_error() to debug drivers that fail
> > to check dma mapping errors on addresses returned by dma_map_single() and
> > dma_map_page() interfaces. This interface clears a flag set by
> > debug_dma_map_page() to indicate that dma_mapping_error() has been called by
> > the driver. When driver does unmap, debug_dma_unmap() checks the flag and if
> > this flag is still set, prints warning message that includes call trace that
> > leads up to the unmap. This interface can be called from dma_mapping_error()
> > routines to enable dma mapping error check debugging.
> >
> > Tested: Intel iommu and swiotlb (iommu=soft) on x86-64 with
> > CONFIG_DMA_API_DEBUG enabled and disabled.
> >
> > Signed-off-by: Shuah Khan <[email protected]>
> > ---
> > Documentation/DMA-API.txt | 12 ++++++
> > arch/x86/include/asm/dma-mapping.h | 1 +
> > include/linux/dma-debug.h | 7 ++++
> > lib/dma-debug.c | 71 ++++++++++++++++++++++++++++++++++--
>
> Third time lucky ... we still haven't fixed Documentation/DMA-API-HOWTO.txt!
>
> Please, go through it and update it to show people how to correctly use
> these APIs.
Yes. Still on my list. I am working on the documentation changes. I am
planning to add usage examples that include calls to dma_mapping_error()
after dma_map_[page/single] calls and programming mistakes to watch out
for such as missing unmaps from error legs etc.
-- Shuah
On Mon, Oct 08, 2012 at 11:08:06AM -0600, Shuah Khan wrote:
> Add dma-debug interface debug_dma_mapping_error() to debug drivers that fail
> to check dma mapping errors on addresses returned by dma_map_single() and
> dma_map_page() interfaces. This interface clears a flag set by
> debug_dma_map_page() to indicate that dma_mapping_error() has been called by
> the driver. When driver does unmap, debug_dma_unmap() checks the flag and if
> this flag is still set, prints warning message that includes call trace that
> leads up to the unmap. This interface can be called from dma_mapping_error()
> routines to enable dma mapping error check debugging.
>
> Tested: Intel iommu and swiotlb (iommu=soft) on x86-64 with
> CONFIG_DMA_API_DEBUG enabled and disabled.
>
> Signed-off-by: Shuah Khan <[email protected]>
Applied, thanks.
--
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