linux-next: build failure after merge of the dma-mapping tree

Hi all,

After merging the dma-mapping tree, today's linux-next build (powerpc64 allnoconfig) failed like this:

In file included from include/linux/dma-direct.h:10,
from arch/powerpc/kernel/dma-iommu.c:9:
include/linux/dma-map-ops.h:328:41: error: expected identifier or '(' before numeric constant
328 | #define arch_dma_map_page_direct(d, a) (0)
| ^
arch/powerpc/kernel/dma-iommu.c:16:6: note: in expansion of macro 'arch_dma_map_page_direct'
16 | bool arch_dma_map_page_direct(struct device *dev, phys_addr_t addr)

      |      ^~~~~~~~~~~~~~~~~~~~~~~~

include/linux/dma-map-ops.h:329:43: error: expected identifier or '(' before numeric constant
329 | #define arch_dma_unmap_page_direct(d, a) (0)
| ^
arch/powerpc/kernel/dma-iommu.c:26:6: note: in expansion of macro 'arch_dma_unmap_page_direct'
26 | bool arch_dma_unmap_page_direct(struct device *dev, dma_addr_t dma_handle)

      |      ^~~~~~~~~~~~~~~~~~~~~~~~~~

include/linux/dma-map-ops.h:330:42: error: expected identifier or '(' before numeric constant
330 | #define arch_dma_map_sg_direct(d, s, n) (0)
| ^
arch/powerpc/kernel/dma-iommu.c:34:6: note: in expansion of macro 'arch_dma_map_sg_direct'
34 | bool arch_dma_map_sg_direct(struct device *dev, struct scatterlist *sg,

      |      ^~~~~~~~~~~~~~~~~~~~~~

include/linux/dma-map-ops.h:331:44: error: expected identifier or '(' before numeric constant
331 | #define arch_dma_unmap_sg_direct(d, s, n) (0)
| ^
arch/powerpc/kernel/dma-iommu.c:51:6: note: in expansion of macro 'arch_dma_unmap_sg_direct'
51 | bool arch_dma_unmap_sg_direct(struct device *dev, struct scatterlist *sg,

      |      ^~~~~~~~~~~~~~~~~~~~~~~~

Caused by commit

4e52b96ac85c ("powerpc/dma: Fallback to dma_ops when persistent memory present")

I have applied the following patch for today.

From: Stephen Rothwell <[email protected]>
Date: Fri, 27 Nov 2020 17:49:28 +1100
Subject: [PATCH] powerpc/dma: fix for "powerpc/dma: Fallback to dma_ops when
persistent memory present"

---
 arch/powerpc/kernel/dma-iommu.c | 3 +++
 1 file changed, 3 insertions(+)

index c724548ca295..6364311eb6e9 100644
@@ -10,6 +10,8 @@
 #include <linux/pci.h>
 #include <asm/iommu.h>
 
+#ifdef CONFIG_ARCH_HAS_DMA_MAP_DIRECT
+
 #define can_map_direct(dev, addr) \
 	((dev)->bus_dma_limit >= phys_to_dma((dev), (addr)))
 

@@ -64,6 +66,7 @@ bool arch_dma_unmap_sg_direct(struct device *dev, struct scatterlist *sg,
 
 	return true;
 }
+#endif /* CONFIG_ARCH_HAS_DMA_MAP_DIRECT */
 
 /*
  * Generic iommu implementation

2.29.2

-- 
Cheers,
Stephen Rothwell

I'm looking into fixing this now, but how do you generate a powerpc64 allnoconfig? My attempts so far either create a ppc32 one or fail entirely.

Hi Christoph,

echo CONFIG_PPC64=y >tmp_conf KCONFIG_ALLCONFIG=tmp_conf make ARCH=powerpc allnoconfig

Cheers,
Stephen Rothwell

I fixed this as shown:

index c724548ca295c0..111249fd619de8 100644
@@ -10,6 +10,7 @@
 #include <linux/pci.h>
 #include <asm/iommu.h>
 
+#ifdef CONFIG_ARCH_HAS_DMA_MAP_DIRECT
 #define can_map_direct(dev, addr) \
 	((dev)->bus_dma_limit >= phys_to_dma((dev), (addr)))
 

@@ -64,6 +65,7 @@ bool arch_dma_unmap_sg_direct(struct device *dev, struct scatterlist *sg,
 
 	return true;
 }
+#endif /* CONFIG_ARCH_HAS_DMA_MAP_DIRECT */
 
 /*
  * Generic iommu implementation