Re: [PATCH 5/6] dma-mapping: Allow batched DMA sync operations if supported by the arch

Re: [PATCH 5/6] dma-mapping: Allow batched DMA sync operations if supported by the arch

[kernel test robot]

Hi Barry,

kernel test robot noticed the following build errors:

[auto build test ERROR on linus/master]
[also build test ERROR on next-20251219]
[cannot apply to arm64/for-next/core v6.16-rc1]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Barry-Song/arm64-Provide-dcache_by_myline_op_nosync-helper/20251219-195810
base:   linus/master
patch link:    https://lore.kernel.org/r/20251219053658.84978-6-21cnbao%40gmail.com
patch subject: [PATCH 5/6] dma-mapping: Allow batched DMA sync operations if supported by the arch
config: x86_64-kexec (https://download.01.org/0day-ci/archive/20251220/202512201836.f6KX6WMH-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251220/202512201836.f6KX6WMH-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202512201836.f6KX6WMH-lkp@intel.com/

All errors (new ones prefixed by >>):

>> kernel/dma/direct.c:456:4: error: call to undeclared function 'dma_direct_unmap_phys_batch_add'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
     456 |                         dma_direct_unmap_phys_batch_add(dev, sg->dma_address,
         |                         ^
   kernel/dma/direct.c:456:4: note: did you mean 'dma_direct_unmap_phys'?
   kernel/dma/direct.h:188:20: note: 'dma_direct_unmap_phys' declared here
     188 | static inline void dma_direct_unmap_phys(struct device *dev, dma_addr_t addr,
         |                    ^
>> kernel/dma/direct.c:484:22: error: call to undeclared function 'dma_direct_map_phys_batch_add'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
     484 |                         sg->dma_address = dma_direct_map_phys_batch_add(dev, sg_phys(sg),
         |                                           ^
   2 errors generated.


vim +/dma_direct_unmap_phys_batch_add +456 kernel/dma/direct.c

   439	
   440	/*
   441	 * Unmaps segments, except for ones marked as pci_p2pdma which do not
   442	 * require any further action as they contain a bus address.
   443	 */
   444	void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sgl,
   445			int nents, enum dma_data_direction dir, unsigned long attrs)
   446	{
   447		struct scatterlist *sg;
   448		int i;
   449		bool need_sync = false;
   450	
   451		for_each_sg(sgl,  sg, nents, i) {
   452			if (sg_dma_is_bus_address(sg)) {
   453				sg_dma_unmark_bus_address(sg);
   454			} else {
   455				need_sync = true;
 > 456				dma_direct_unmap_phys_batch_add(dev, sg->dma_address,
   457						      sg_dma_len(sg), dir, attrs);
   458			}
   459		}
   460		if (need_sync && !dev_is_dma_coherent(dev))
   461			arch_sync_dma_batch_flush();
   462	}
   463	#endif
   464	
   465	int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents,
   466			enum dma_data_direction dir, unsigned long attrs)
   467	{
   468		struct pci_p2pdma_map_state p2pdma_state = {};
   469		struct scatterlist *sg;
   470		int i, ret;
   471		bool need_sync = false;
   472	
   473		for_each_sg(sgl, sg, nents, i) {
   474			switch (pci_p2pdma_state(&p2pdma_state, dev, sg_page(sg))) {
   475			case PCI_P2PDMA_MAP_THRU_HOST_BRIDGE:
   476				/*
   477				 * Any P2P mapping that traverses the PCI host bridge
   478				 * must be mapped with CPU physical address and not PCI
   479				 * bus addresses.
   480				 */
   481				break;
   482			case PCI_P2PDMA_MAP_NONE:
   483				need_sync = true;
 > 484				sg->dma_address = dma_direct_map_phys_batch_add(dev, sg_phys(sg),
   485						sg->length, dir, attrs);
   486				if (sg->dma_address == DMA_MAPPING_ERROR) {
   487					ret = -EIO;
   488					goto out_unmap;
   489				}
   490				break;
   491			case PCI_P2PDMA_MAP_BUS_ADDR:
   492				sg->dma_address = pci_p2pdma_bus_addr_map(
   493					p2pdma_state.mem, sg_phys(sg));
   494				sg_dma_len(sg) = sg->length;
   495				sg_dma_mark_bus_address(sg);
   496				continue;
   497			default:
   498				ret = -EREMOTEIO;
   499				goto out_unmap;
   500			}
   501			sg_dma_len(sg) = sg->length;
   502		}
   503	
   504		if (need_sync && !dev_is_dma_coherent(dev))
   505			arch_sync_dma_batch_flush();
   506		return nents;
   507	
   508	out_unmap:
   509		dma_direct_unmap_sg(dev, sgl, i, dir, attrs | DMA_ATTR_SKIP_CPU_SYNC);
   510		return ret;
   511	}
   512	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH 5/6] dma-mapping: Allow batched DMA sync operations if supported by the arch

[Barry Song]

>
> All errors (new ones prefixed by >>):
>
> >> kernel/dma/direct.c:456:4: error: call to undeclared function 'dma_direct_unmap_phys_batch_add'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
>      456 |                         dma_direct_unmap_phys_batch_add(dev, sg->dma_address,
>          |                         ^
>    kernel/dma/direct.c:456:4: note: did you mean 'dma_direct_unmap_phys'?
>    kernel/dma/direct.h:188:20: note: 'dma_direct_unmap_phys' declared here
>      188 | static inline void dma_direct_unmap_phys(struct device *dev, dma_addr_t addr,
>          |                    ^
> >> kernel/dma/direct.c:484:22: error: call to undeclared function 'dma_direct_map_phys_batch_add'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
>      484 |                         sg->dma_address = dma_direct_map_phys_batch_add(dev, sg_phys(sg),
>          |                                           ^
>    2 errors generated.
>
>

Thanks very much for the report.
Can you please check if the below diff fix the build issue?

From 5541aa1efa19777e435c9f3cca7cd2c6a490d9f1 Mon Sep 17 00:00:00 2001
From: Barry Song <v-songbaohua@oppo.com>
Date: Sun, 21 Dec 2025 13:09:36 +0800
Subject: [PATCH] kernel/dma: Fix build errors for dma_direct_map_phys

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202512201836.f6KX6WMH-lkp@intel.com/
Signed-off-by: Barry Song <v-songbaohua@oppo.com>
---
 kernel/dma/direct.h | 38 ++++++++++++++++++++++++++------------
 1 file changed, 26 insertions(+), 12 deletions(-)

diff --git a/kernel/dma/direct.h b/kernel/dma/direct.h
index a211bab26478..bcc398b5aa6b 100644
--- a/kernel/dma/direct.h
+++ b/kernel/dma/direct.h
@@ -138,8 +138,7 @@ static inline dma_addr_t __dma_direct_map_phys(struct device *dev,
 	return DMA_MAPPING_ERROR;
 }
 
-#ifdef CONFIG_ARCH_WANT_BATCHED_DMA_SYNC
-static inline dma_addr_t dma_direct_map_phys_batch_add(struct device *dev,
+static inline dma_addr_t dma_direct_map_phys(struct device *dev,
 		phys_addr_t phys, size_t size, enum dma_data_direction dir,
 		unsigned long attrs)
 {
@@ -147,13 +146,13 @@ static inline dma_addr_t dma_direct_map_phys_batch_add(struct device *dev,
 
 	if (dma_addr != DMA_MAPPING_ERROR && !dev_is_dma_coherent(dev) &&
 	    !(attrs & (DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_MMIO)))
-		arch_sync_dma_for_device_batch_add(phys, size, dir);
+		arch_sync_dma_for_device(phys, size, dir);
 
 	return dma_addr;
 }
-#endif
 
-static inline dma_addr_t dma_direct_map_phys(struct device *dev,
+#ifdef CONFIG_ARCH_WANT_BATCHED_DMA_SYNC
+static inline dma_addr_t dma_direct_map_phys_batch_add(struct device *dev,
 		phys_addr_t phys, size_t size, enum dma_data_direction dir,
 		unsigned long attrs)
 {
@@ -161,13 +160,20 @@ static inline dma_addr_t dma_direct_map_phys(struct device *dev,
 
 	if (dma_addr != DMA_MAPPING_ERROR && !dev_is_dma_coherent(dev) &&
 	    !(attrs & (DMA_ATTR_SKIP_CPU_SYNC | DMA_ATTR_MMIO)))
-		arch_sync_dma_for_device(phys, size, dir);
+		arch_sync_dma_for_device_batch_add(phys, size, dir);
 
 	return dma_addr;
 }
+#else
+static inline dma_addr_t dma_direct_map_phys_batch_add(struct device *dev,
+		phys_addr_t phys, size_t size, enum dma_data_direction dir,
+		unsigned long attrs)
+{
+	return dma_direct_map_phys(dev, phys, size, dir, attrs);
+}
+#endif
 
-#ifdef CONFIG_ARCH_WANT_BATCHED_DMA_SYNC
-static inline void dma_direct_unmap_phys_batch_add(struct device *dev, dma_addr_t addr,
+static inline void dma_direct_unmap_phys(struct device *dev, dma_addr_t addr,
 		size_t size, enum dma_data_direction dir, unsigned long attrs)
 {
 	phys_addr_t phys;
@@ -178,14 +184,14 @@ static inline void dma_direct_unmap_phys_batch_add(struct device *dev, dma_addr_
 
 	phys = dma_to_phys(dev, addr);
 	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
-		dma_direct_sync_single_for_cpu_batch_add(dev, addr, size, dir);
+		dma_direct_sync_single_for_cpu(dev, addr, size, dir);
 
 	swiotlb_tbl_unmap_single(dev, phys, size, dir,
 					 attrs | DMA_ATTR_SKIP_CPU_SYNC);
 }
-#endif
 
-static inline void dma_direct_unmap_phys(struct device *dev, dma_addr_t addr,
+#ifdef CONFIG_ARCH_WANT_BATCHED_DMA_SYNC
+static inline void dma_direct_unmap_phys_batch_add(struct device *dev, dma_addr_t addr,
 		size_t size, enum dma_data_direction dir, unsigned long attrs)
 {
 	phys_addr_t phys;
@@ -196,9 +202,17 @@ static inline void dma_direct_unmap_phys(struct device *dev, dma_addr_t addr,
 
 	phys = dma_to_phys(dev, addr);
 	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
-		dma_direct_sync_single_for_cpu(dev, addr, size, dir);
+		dma_direct_sync_single_for_cpu_batch_add(dev, addr, size, dir);
 
 	swiotlb_tbl_unmap_single(dev, phys, size, dir,
 					 attrs | DMA_ATTR_SKIP_CPU_SYNC);
 }
+#else
+static inline void dma_direct_unmap_phys_batch_add(struct device *dev, dma_addr_t addr,
+		size_t size, enum dma_data_direction dir, unsigned long attrs)
+{
+	dma_direct_unmap_phys(dev, addr, size, dir, attrs);
+}
+#endif
+
 #endif /* _KERNEL_DMA_DIRECT_H */
-- 
2.39.3 (Apple Git-146)

Thanks
Barry

Re: [PATCH 5/6] dma-mapping: Allow batched DMA sync operations if supported by the arch

[kernel test robot]

Hi Barry,

kernel test robot noticed the following build errors:

[auto build test ERROR on linus/master]
[also build test ERROR on v6.19-rc2 next-20251219]
[cannot apply to arm64/for-next/core]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Barry-Song/arm64-Provide-dcache_by_myline_op_nosync-helper/20251219-195810
base:   linus/master
patch link:    https://lore.kernel.org/r/20251219053658.84978-6-21cnbao%40gmail.com
patch subject: [PATCH 5/6] dma-mapping: Allow batched DMA sync operations if supported by the arch
config: i386-buildonly-randconfig-006-20251222 (https://download.01.org/0day-ci/archive/20251222/202512222029.Dd6Vs1Eg-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251222/202512222029.Dd6Vs1Eg-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202512222029.Dd6Vs1Eg-lkp@intel.com/

All errors (new ones prefixed by >>):

>> kernel/dma/direct.c:456:4: error: call to undeclared function 'dma_direct_unmap_phys_batch_add'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
     456 |                         dma_direct_unmap_phys_batch_add(dev, sg->dma_address,
         |                         ^
   kernel/dma/direct.c:456:4: note: did you mean 'dma_direct_unmap_phys'?
   kernel/dma/direct.h:188:20: note: 'dma_direct_unmap_phys' declared here
     188 | static inline void dma_direct_unmap_phys(struct device *dev, dma_addr_t addr,
         |                    ^
>> kernel/dma/direct.c:484:22: error: call to undeclared function 'dma_direct_map_phys_batch_add'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
     484 |                         sg->dma_address = dma_direct_map_phys_batch_add(dev, sg_phys(sg),
         |                                           ^
   2 errors generated.


vim +/dma_direct_unmap_phys_batch_add +456 kernel/dma/direct.c

   439	
   440	/*
   441	 * Unmaps segments, except for ones marked as pci_p2pdma which do not
   442	 * require any further action as they contain a bus address.
   443	 */
   444	void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sgl,
   445			int nents, enum dma_data_direction dir, unsigned long attrs)
   446	{
   447		struct scatterlist *sg;
   448		int i;
   449		bool need_sync = false;
   450	
   451		for_each_sg(sgl,  sg, nents, i) {
   452			if (sg_dma_is_bus_address(sg)) {
   453				sg_dma_unmark_bus_address(sg);
   454			} else {
   455				need_sync = true;
 > 456				dma_direct_unmap_phys_batch_add(dev, sg->dma_address,
   457						      sg_dma_len(sg), dir, attrs);
   458			}
   459		}
   460		if (need_sync && !dev_is_dma_coherent(dev))
   461			arch_sync_dma_batch_flush();
   462	}
   463	#endif
   464	
   465	int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents,
   466			enum dma_data_direction dir, unsigned long attrs)
   467	{
   468		struct pci_p2pdma_map_state p2pdma_state = {};
   469		struct scatterlist *sg;
   470		int i, ret;
   471		bool need_sync = false;
   472	
   473		for_each_sg(sgl, sg, nents, i) {
   474			switch (pci_p2pdma_state(&p2pdma_state, dev, sg_page(sg))) {
   475			case PCI_P2PDMA_MAP_THRU_HOST_BRIDGE:
   476				/*
   477				 * Any P2P mapping that traverses the PCI host bridge
   478				 * must be mapped with CPU physical address and not PCI
   479				 * bus addresses.
   480				 */
   481				break;
   482			case PCI_P2PDMA_MAP_NONE:
   483				need_sync = true;
 > 484				sg->dma_address = dma_direct_map_phys_batch_add(dev, sg_phys(sg),
   485						sg->length, dir, attrs);
   486				if (sg->dma_address == DMA_MAPPING_ERROR) {
   487					ret = -EIO;
   488					goto out_unmap;
   489				}
   490				break;
   491			case PCI_P2PDMA_MAP_BUS_ADDR:
   492				sg->dma_address = pci_p2pdma_bus_addr_map(
   493					p2pdma_state.mem, sg_phys(sg));
   494				sg_dma_len(sg) = sg->length;
   495				sg_dma_mark_bus_address(sg);
   496				continue;
   497			default:
   498				ret = -EREMOTEIO;
   499				goto out_unmap;
   500			}
   501			sg_dma_len(sg) = sg->length;
   502		}
   503	
   504		if (need_sync && !dev_is_dma_coherent(dev))
   505			arch_sync_dma_batch_flush();
   506		return nents;
   507	
   508	out_unmap:
   509		dma_direct_unmap_sg(dev, sgl, i, dir, attrs | DMA_ATTR_SKIP_CPU_SYNC);
   510		return ret;
   511	}
   512	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki