dma-debug: add support for resource mappings

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 <niklas.soderlund+renesas@ragnatech.se>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

2 files changed, 69 insertions, 2 deletions

diff --git a/include/linux/dma-debug.h b/include/linux/dma-debug.h
index fe8cb610deac..c7d844f09c3a 100644
--- a/include/linux/dma-debug.h
+++ b/include/linux/dma-debug.h
@@ -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);
@@ -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)
diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index fcfa1939ac41..2ba086b0d3e7 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -43,6 +43,7 @@ enum {
         dma_debug_page,
         dma_debug_sg,
         dma_debug_coherent,
+        dma_debug_resource,
 };
 
 enum map_err_types {
@@ -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" };
@@ -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;
 }
 
@@ -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)
 {