[PATCH 3/3] CMA: use new memblock interfaces to simplifyimplementation

[Jiang Liu]

This patch simplifies dma-continuous.c by using new memblock interfaces.

Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxx>
---
 drivers/base/Kconfig          |    1 +
 drivers/base/dma-contiguous.c |   36 +++++++++++++-----------------------
 include/linux/memblock.h      |    1 +
 3 files changed, 15 insertions(+), 23 deletions(-)

diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
index b34b5cd..b0ac008 100644
--- a/drivers/base/Kconfig
+++ b/drivers/base/Kconfig
@@ -197,6 +197,7 @@ config CMA
 	depends on HAVE_DMA_CONTIGUOUS && HAVE_MEMBLOCK && EXPERIMENTAL
 	select MIGRATION
 	select MEMORY_ISOLATION
+	select HAVE_MEMBLOCK_TAG
 	help
 	  This enables the Contiguous Memory Allocator which allows drivers
 	  to allocate big physically-contiguous blocks of memory for use with
diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c
index 612afcc..c092b76 100644
--- a/drivers/base/dma-contiguous.c
+++ b/drivers/base/dma-contiguous.c
@@ -190,27 +190,24 @@ no_mem:
 	return ERR_PTR(ret);
 }
 
-static struct cma_reserved {
-	phys_addr_t start;
-	unsigned long size;
-	struct device *dev;
-} cma_reserved[MAX_CMA_AREAS] __initdata;
 static unsigned cma_reserved_count __initdata;
 
 static int __init cma_init_reserved_areas(void)
 {
-	struct cma_reserved *r = cma_reserved;
-	unsigned i = cma_reserved_count;
+	struct memblock_region *reg;
+	struct cma *cma;
 
 	pr_debug("%s()\n", __func__);
 
-	for (; i; --i, ++r) {
-		struct cma *cma;
-		cma = cma_create_area(PFN_DOWN(r->start),
-				      r->size >> PAGE_SHIFT);
-		if (!IS_ERR(cma))
-			dev_set_cma_area(r->dev, cma);
-	}
+	for_each_memblock(memory, reg)
+		if (reg->tag == MEMBLOCK_TAG_CMA) {
+			cma = cma_create_area(PFN_DOWN(reg->base),
+					      reg->size >> PAGE_SHIFT);
+			if (!IS_ERR(cma))
+				dev_set_cma_area(reg->data, cma);
+		}
+	memblock_free_all_with_tag(MEMBLOCK_TAG_CMA);
+
 	return 0;
 }
 core_initcall(cma_init_reserved_areas);
@@ -230,7 +227,6 @@ core_initcall(cma_init_reserved_areas);
 int __init dma_declare_contiguous(struct device *dev, unsigned long size,
 				  phys_addr_t base, phys_addr_t limit)
 {
-	struct cma_reserved *r = &cma_reserved[cma_reserved_count];
 	unsigned long alignment;
 
 	pr_debug("%s(size %lx, base %08lx, limit %08lx)\n", __func__,
@@ -238,7 +234,7 @@ int __init dma_declare_contiguous(struct device *dev, unsigned long size,
 		 (unsigned long)limit);
 
 	/* Sanity checks */
-	if (cma_reserved_count == ARRAY_SIZE(cma_reserved)) {
+	if (cma_reserved_count == MAX_CMA_AREAS) {
 		pr_err("Not enough slots for CMA reserved regions!\n");
 		return -ENOSPC;
 	}
@@ -277,13 +273,7 @@ int __init dma_declare_contiguous(struct device *dev, unsigned long size,
 		}
 	}
 
-	/*
-	 * Each reserved area must be initialised later, when more kernel
-	 * subsystems (like slab allocator) are available.
-	 */
-	r->start = base;
-	r->size = size;
-	r->dev = dev;
+	BUG_ON(memblock_mark_tag(base, size, MEMBLOCK_TAG_CMA, dev));
 	cma_reserved_count++;
 	pr_info("CMA: reserved %ld MiB at %08lx\n", size / SZ_1M,
 		(unsigned long)base);
diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index 5420ed9..a662c07 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -125,6 +125,7 @@ void __next_free_mem_range_rev(u64 *idx, int nid, phys_addr_t *out_start,
 #ifdef CONFIG_HAVE_MEMBLOCK_TAG
 #define	MEMBLOCK_TAG_DEFAULT	0x0 /* default tag for bootmem allocatror */
 #define	MEMBLOCK_TAG_HOTPLUG	0x1 /* reserved for memory hotplug */
+#define	MEMBLOCK_TAG_CMA	0x2 /* reserved for CMA */
 
 int memblock_mark_tag(phys_addr_t base, phys_addr_t size, int tag, void *data);
 void memblock_free_all_with_tag(int tag);
-- 
1.7.9.5


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