Merge branch 'dma-contig-for-7.1-modules-prep-v4' into dma-mapping-for-next

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>

drivers/dma-buf/heaps/cma_heap.c

@@ -14,7 +14,6 @@
 
 #include <linux/cma.h>
 #include <linux/dma-buf.h>
-#include <linux/dma-buf/heaps/cma.h>
 #include <linux/dma-heap.h>
 #include <linux/dma-map-ops.h>
 #include <linux/err.h>
@@ -30,19 +29,6 @@
 
 #define DEFAULT_CMA_NAME "default_cma_region"
 
-static struct cma *dma_areas[MAX_CMA_AREAS] __initdata;
-static unsigned int dma_areas_num __initdata;
-
-int __init dma_heap_cma_register_heap(struct cma *cma)
-{
-	if (dma_areas_num >= ARRAY_SIZE(dma_areas))
-		return -EINVAL;
-
-	dma_areas[dma_areas_num++] = cma;
-
-	return 0;
-}
-
 struct cma_heap {
 	struct dma_heap *heap;
 	struct cma *cma;
@@ -414,6 +400,7 @@ static int __init __add_cma_heap(struct cma *cma, const char *name)
 static int __init add_cma_heaps(void)
 {
 	struct cma *default_cma = dev_get_cma_area(NULL);
+	struct cma *cma;
 	unsigned int i;
 	int ret;
 
@@ -423,9 +410,7 @@ static int __init add_cma_heaps(void)
 			return ret;
 	}
 
-	for (i = 0; i < dma_areas_num; i++) {
-		struct cma *cma = dma_areas[i];
-
+	for (i = 0; (cma = dma_contiguous_get_area_by_idx(i)) != NULL; i++) {
 		ret = __add_cma_heap(cma, cma_get_name(cma));
 		if (ret) {
 			pr_warn("Failed to add CMA heap %s", cma_get_name(cma));

include/linux/dma-buf/heaps/cma.h

@@ -1,16 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef DMA_BUF_HEAP_CMA_H_
-#define DMA_BUF_HEAP_CMA_H_
-
-struct cma;
-
-#ifdef CONFIG_DMABUF_HEAPS_CMA
-int dma_heap_cma_register_heap(struct cma *cma);
-#else
-static inline int dma_heap_cma_register_heap(struct cma *cma)
-{
-	return 0;
-}
-#endif // CONFIG_DMABUF_HEAPS_CMA
-
-#endif // DMA_BUF_HEAP_CMA_H_

include/linux/dma-map-ops.h

@@ -91,14 +91,8 @@ static inline void set_dma_ops(struct device *dev,
 #endif /* CONFIG_ARCH_HAS_DMA_OPS */
 
 #ifdef CONFIG_DMA_CMA
-extern struct cma *dma_contiguous_default_area;
-
-static inline struct cma *dev_get_cma_area(struct device *dev)
-{
-	if (dev && dev->cma_area)
-		return dev->cma_area;
-	return dma_contiguous_default_area;
-}
+struct cma *dev_get_cma_area(struct device *dev);
+struct cma *dma_contiguous_get_area_by_idx(unsigned int idx);
 
 void dma_contiguous_reserve(phys_addr_t addr_limit);
 int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base,
@@ -117,6 +111,10 @@ static inline struct cma *dev_get_cma_area(struct device *dev)
 {
 	return NULL;
 }
+static inline struct cma *dma_contiguous_get_area_by_idx(unsigned int idx)
+{
+	return NULL;
+}
 static inline void dma_contiguous_reserve(phys_addr_t limit)
 {
 }

kernel/dma/contiguous.c

@@ -42,7 +42,6 @@
 #include <linux/memblock.h>
 #include <linux/err.h>
 #include <linux/sizes.h>
-#include <linux/dma-buf/heaps/cma.h>
 #include <linux/dma-map-ops.h>
 #include <linux/cma.h>
 #include <linux/nospec.h>
@@ -53,7 +52,38 @@
 #define CMA_SIZE_MBYTES 0
 #endif
 
-struct cma *dma_contiguous_default_area;
+static struct cma *dma_contiguous_areas[MAX_CMA_AREAS];
+static unsigned int dma_contiguous_areas_num;
+
+static int dma_contiguous_insert_area(struct cma *cma)
+{
+	if (dma_contiguous_areas_num >= ARRAY_SIZE(dma_contiguous_areas))
+		return -EINVAL;
+
+	dma_contiguous_areas[dma_contiguous_areas_num++] = cma;
+
+	return 0;
+}
+
+/**
+ * dma_contiguous_get_area_by_idx() - Get contiguous area at given index
+ * @idx: index of the area we query
+ *
+ * Queries for the contiguous area located at index @idx.
+ *
+ * Returns:
+ * A pointer to the requested contiguous area, or NULL otherwise.
+ */
+struct cma *dma_contiguous_get_area_by_idx(unsigned int idx)
+{
+	if (idx >= dma_contiguous_areas_num)
+		return NULL;
+
+	return dma_contiguous_areas[idx];
+}
+EXPORT_SYMBOL_GPL(dma_contiguous_get_area_by_idx);
+
+static struct cma *dma_contiguous_default_area;
 
 /*
  * Default global CMA area size can be defined in kernel's .config.
@@ -91,6 +121,15 @@ static int __init early_cma(char *p)
 }
 early_param("cma", early_cma);
 
+struct cma *dev_get_cma_area(struct device *dev)
+{
+	if (dev && dev->cma_area)
+		return dev->cma_area;
+
+	return dma_contiguous_default_area;
+}
+EXPORT_SYMBOL_GPL(dev_get_cma_area);
+
 #ifdef CONFIG_DMA_NUMA_CMA
 
 static struct cma *dma_contiguous_numa_area[MAX_NUMNODES];
@@ -254,9 +293,24 @@ void __init dma_contiguous_reserve(phys_addr_t limit)
 		if (ret)
 			return;
 
-		ret = dma_heap_cma_register_heap(dma_contiguous_default_area);
+		/*
+		 * We need to insert the new area in our list to avoid
+		 * any inconsistencies between having the default area
+		 * listed in the DT or not.
+		 *
+		 * The DT case is handled by rmem_cma_setup() and will
+		 * always insert all its areas in our list. However, if
+		 * it didn't run (because OF_RESERVED_MEM isn't set, or
+		 * there's no DT region specified), then we don't have a
+		 * default area yet, and no area in our list.
+		 *
+		 * This block creates the default area in such a case,
+		 * but we also need to insert it in our list to avoid
+		 * having a default area but an empty list.
+		 */
+		ret = dma_contiguous_insert_area(dma_contiguous_default_area);
 		if (ret)
-			pr_warn("Couldn't register default CMA heap.");
+			pr_warn("Couldn't queue default CMA region for heap creation.");
 	}
 }
 
@@ -529,9 +583,9 @@ static int __init rmem_cma_setup(unsigned long node, struct reserved_mem *rmem)
 	pr_info("Reserved memory: created CMA memory pool at %pa, size %ld MiB\n",
 		&rmem->base, (unsigned long)rmem->size / SZ_1M);
 
-	ret = dma_heap_cma_register_heap(cma);
+	ret = dma_contiguous_insert_area(cma);
 	if (ret)
-		pr_warn("Couldn't register CMA heap.");
+		pr_warn("Couldn't store CMA reserved area.");
 
 	return 0;
 }

mm/cma.c

@@ -52,6 +52,7 @@ const char *cma_get_name(const struct cma *cma)
 {
 	return cma->name;
 }
+EXPORT_SYMBOL_GPL(cma_get_name);
 
 static unsigned long cma_bitmap_aligned_mask(const struct cma *cma,
 					     unsigned int align_order)
@@ -951,6 +952,7 @@ struct page *cma_alloc(struct cma *cma, unsigned long count,
 
 	return page;
 }
+EXPORT_SYMBOL_GPL(cma_alloc);
 
 static struct cma_memrange *find_cma_memrange(struct cma *cma,
 		const struct page *pages, unsigned long count)
@@ -1027,6 +1029,7 @@ bool cma_release(struct cma *cma, const struct page *pages,
 
 	return true;
 }
+EXPORT_SYMBOL_GPL(cma_release);
 
 bool cma_release_frozen(struct cma *cma, const struct page *pages,
 		unsigned long count)