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dma-debug: add support for resource mappings
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A MMIO mapped resource can not be represented by a struct page so a new
debug type is needed to handle this. This patch add such type and
functionality to add/remove entries and how to translate them to a
physical address.

Signed-off-by: Niklas Söderlund <[email protected]>
Acked-by: Arnd Bergmann <[email protected]>
Signed-off-by: Vinod Koul <[email protected]>
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Niklas Söderlund authored and Vinod Koul committed Sep 26, 2016
1 parent ba409b3 commit 0e74b34
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Showing 2 changed files with 69 additions and 2 deletions.
19 changes: 19 additions & 0 deletions include/linux/dma-debug.h
Original file line number Diff line number Diff line change
Expand Up @@ -56,6 +56,13 @@ extern void debug_dma_alloc_coherent(struct device *dev, size_t size,
extern void debug_dma_free_coherent(struct device *dev, size_t size,
void *virt, dma_addr_t addr);

extern void debug_dma_map_resource(struct device *dev, phys_addr_t addr,
size_t size, int direction,
dma_addr_t dma_addr);

extern void debug_dma_unmap_resource(struct device *dev, dma_addr_t dma_addr,
size_t size, int direction);

extern void debug_dma_sync_single_for_cpu(struct device *dev,
dma_addr_t dma_handle, size_t size,
int direction);
Expand Down Expand Up @@ -141,6 +148,18 @@ static inline void debug_dma_free_coherent(struct device *dev, size_t size,
{
}

static inline void debug_dma_map_resource(struct device *dev, phys_addr_t addr,
size_t size, int direction,
dma_addr_t dma_addr)
{
}

static inline void debug_dma_unmap_resource(struct device *dev,
dma_addr_t dma_addr, size_t size,
int direction)
{
}

static inline void debug_dma_sync_single_for_cpu(struct device *dev,
dma_addr_t dma_handle,
size_t size, int direction)
Expand Down
52 changes: 50 additions & 2 deletions lib/dma-debug.c
Original file line number Diff line number Diff line change
Expand Up @@ -43,6 +43,7 @@ enum {
dma_debug_page,
dma_debug_sg,
dma_debug_coherent,
dma_debug_resource,
};

enum map_err_types {
Expand Down Expand Up @@ -150,8 +151,9 @@ static const char *const maperr2str[] = {
[MAP_ERR_CHECKED] = "dma map error checked",
};

static const char *type2name[4] = { "single", "page",
"scather-gather", "coherent" };
static const char *type2name[5] = { "single", "page",
"scather-gather", "coherent",
"resource" };

static const char *dir2name[4] = { "DMA_BIDIRECTIONAL", "DMA_TO_DEVICE",
"DMA_FROM_DEVICE", "DMA_NONE" };
Expand Down Expand Up @@ -399,6 +401,9 @@ static void hash_bucket_del(struct dma_debug_entry *entry)

static unsigned long long phys_addr(struct dma_debug_entry *entry)
{
if (entry->type == dma_debug_resource)
return __pfn_to_phys(entry->pfn) + entry->offset;

return page_to_phys(pfn_to_page(entry->pfn)) + entry->offset;
}

Expand Down Expand Up @@ -1495,6 +1500,49 @@ void debug_dma_free_coherent(struct device *dev, size_t size,
}
EXPORT_SYMBOL(debug_dma_free_coherent);

void debug_dma_map_resource(struct device *dev, phys_addr_t addr, size_t size,
int direction, dma_addr_t dma_addr)
{
struct dma_debug_entry *entry;

if (unlikely(dma_debug_disabled()))
return;

entry = dma_entry_alloc();
if (!entry)
return;

entry->type = dma_debug_resource;
entry->dev = dev;
entry->pfn = __phys_to_pfn(addr);
entry->offset = offset_in_page(addr);
entry->size = size;
entry->dev_addr = dma_addr;
entry->direction = direction;
entry->map_err_type = MAP_ERR_NOT_CHECKED;

add_dma_entry(entry);
}
EXPORT_SYMBOL(debug_dma_map_resource);

void debug_dma_unmap_resource(struct device *dev, dma_addr_t dma_addr,
size_t size, int direction)
{
struct dma_debug_entry ref = {
.type = dma_debug_resource,
.dev = dev,
.dev_addr = dma_addr,
.size = size,
.direction = direction,
};

if (unlikely(dma_debug_disabled()))
return;

check_unmap(&ref);
}
EXPORT_SYMBOL(debug_dma_unmap_resource);

void debug_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
size_t size, int direction)
{
Expand Down

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