dma-coherent: introduce interface for default DMA pool
Christoph noticed [1] that default DMA pool in current form overload
the DMA coherent infrastructure. In reply, Robin suggested [2] to
split the per-device vs. global pool interfaces, so allocation/release
from default DMA pool is driven by dma ops implementation.
This patch implements Robin's idea and provide interface to
allocate/release/mmap the default (aka global) DMA pool.
To make it clear that existing *_from_coherent routines work on
per-device pool rename them to *_from_dev_coherent.
[1] https://lkml.org/lkml/2017/7/7/370
[2] https://lkml.org/lkml/2017/7/7/431
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Suggested-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Andras Szemzo <sza@esh.hu>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 843ab86..03c0196 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -157,16 +157,40 @@
* These three functions are only for dma allocator.
* Don't use them in device drivers.
*/
-int dma_alloc_from_coherent(struct device *dev, ssize_t size,
+int dma_alloc_from_dev_coherent(struct device *dev, ssize_t size,
dma_addr_t *dma_handle, void **ret);
-int dma_release_from_coherent(struct device *dev, int order, void *vaddr);
+int dma_release_from_dev_coherent(struct device *dev, int order, void *vaddr);
-int dma_mmap_from_coherent(struct device *dev, struct vm_area_struct *vma,
+int dma_mmap_from_dev_coherent(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, size_t size, int *ret);
+
+void *dma_alloc_from_global_coherent(ssize_t size, dma_addr_t *dma_handle);
+int dma_release_from_global_coherent(int order, void *vaddr);
+int dma_mmap_from_global_coherent(struct vm_area_struct *vma, void *cpu_addr,
+ size_t size, int *ret);
+
#else
-#define dma_alloc_from_coherent(dev, size, handle, ret) (0)
-#define dma_release_from_coherent(dev, order, vaddr) (0)
-#define dma_mmap_from_coherent(dev, vma, vaddr, order, ret) (0)
+#define dma_alloc_from_dev_coherent(dev, size, handle, ret) (0)
+#define dma_release_from_dev_coherent(dev, order, vaddr) (0)
+#define dma_mmap_from_dev_coherent(dev, vma, vaddr, order, ret) (0)
+
+static inline void *dma_alloc_from_global_coherent(ssize_t size,
+ dma_addr_t *dma_handle)
+{
+ return NULL;
+}
+
+static inline int dma_release_from_global_coherent(int order, void *vaddr)
+{
+ return 0;
+}
+
+static inline int dma_mmap_from_global_coherent(struct vm_area_struct *vma,
+ void *cpu_addr, size_t size,
+ int *ret)
+{
+ return 0;
+}
#endif /* CONFIG_HAVE_GENERIC_DMA_COHERENT */
#ifdef CONFIG_HAS_DMA
@@ -481,7 +505,7 @@
BUG_ON(!ops);
- if (dma_alloc_from_coherent(dev, size, dma_handle, &cpu_addr))
+ if (dma_alloc_from_dev_coherent(dev, size, dma_handle, &cpu_addr))
return cpu_addr;
if (!arch_dma_alloc_attrs(&dev, &flag))
@@ -503,7 +527,7 @@
BUG_ON(!ops);
WARN_ON(irqs_disabled());
- if (dma_release_from_coherent(dev, get_order(size), cpu_addr))
+ if (dma_release_from_dev_coherent(dev, get_order(size), cpu_addr))
return;
if (!ops->free || !cpu_addr)