[PATCH v2] of: reserved_mem: Restructure call site for dma_contiguous_early_fixup()

[PATCH v2] of: reserved_mem: Restructure call site for dma_contiguous_early_fixup()

[Oreoluwa Babatunde]

Restructure the call site for dma_contiguous_early_fixup() to
where the reserved_mem nodes are being parsed from the DT so that
dma_mmu_remap[] is populated before dma_contiguous_remap() is called.

Fixes: 8a6e02d0c00e ("of: reserved_mem: Restructure how the reserved memory regions are processed")
Signed-off-by: Oreoluwa Babatunde <oreoluwa.babatunde@oss.qualcomm.com>
---
v2: Add a check for the "reusable" property to narrow things down to
    only cma regions.
    Also add __weak function definition for dma_contiguous_early_fixup()
    to avoid compile errors on architectures that do not define the
    function.

 drivers/of/of_reserved_mem.c | 21 ++++++++++++++++++---
 kernel/dma/contiguous.c      |  2 --
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
index 77016c0cc296..eee96172883a 100644
--- a/drivers/of/of_reserved_mem.c
+++ b/drivers/of/of_reserved_mem.c
@@ -25,6 +25,7 @@
 #include <linux/memblock.h>
 #include <linux/kmemleak.h>
 #include <linux/cma.h>
+#include <linux/dma-map-ops.h>
 
 #include "of_private.h"
 
@@ -147,6 +148,11 @@ static int __init early_init_dt_reserve_memory(phys_addr_t base,
 	return memblock_reserve(base, size);
 }
 
+void __weak
+dma_contiguous_early_fixup(phys_addr_t base, unsigned long size)
+{
+}
+
 /*
  * __reserved_mem_reserve_reg() - reserve all memory described in 'reg' property
  */
@@ -175,13 +181,18 @@ static int __init __reserved_mem_reserve_reg(unsigned long node,
 		base = dt_mem_next_cell(dt_root_addr_cells, &prop);
 		size = dt_mem_next_cell(dt_root_size_cells, &prop);
 
-		if (size &&
-		    early_init_dt_reserve_memory(base, size, nomap) == 0)
+		if (size && early_init_dt_reserve_memory(base, size, nomap) == 0) {
+			/* Architecture specific contiguous memory fixup. */
+			if (of_flat_dt_is_compatible(node, "shared-dma-pool") &&
+			    of_get_flat_dt_prop(node, "reusable", NULL))
+				dma_contiguous_early_fixup(base, size);
+
 			pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %lu MiB\n",
 				uname, &base, (unsigned long)(size / SZ_1M));
-		else
+		} else {
 			pr_err("Reserved memory: failed to reserve memory for node '%s': base %pa, size %lu MiB\n",
 			       uname, &base, (unsigned long)(size / SZ_1M));
+		}
 
 		len -= t_len;
 	}
@@ -472,6 +483,10 @@ static int __init __reserved_mem_alloc_size(unsigned long node, const char *unam
 		       uname, (unsigned long)(size / SZ_1M));
 		return -ENOMEM;
 	}
+	/* Architecture specific contiguous memory fixup. */
+	if (of_flat_dt_is_compatible(node, "shared-dma-pool") &&
+	    of_get_flat_dt_prop(node, "reusable", NULL))
+		dma_contiguous_early_fixup(base, size);
 
 	/* Save region in the reserved_mem array */
 	fdt_reserved_mem_save_node(node, uname, base, size);
diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c
index 67af8a55185d..d9b9dcba6ff7 100644
--- a/kernel/dma/contiguous.c
+++ b/kernel/dma/contiguous.c
@@ -483,8 +483,6 @@ static int __init rmem_cma_setup(struct reserved_mem *rmem)
 		pr_err("Reserved memory: unable to setup CMA region\n");
 		return err;
 	}
-	/* Architecture specific contiguous memory fixup. */
-	dma_contiguous_early_fixup(rmem->base, rmem->size);
 
 	if (default_cma)
 		dma_contiguous_default_area = cma;
-- 
2.34.1

Re: [PATCH v2] of: reserved_mem: Restructure call site for dma_contiguous_early_fixup()

[kernel test robot]

Hi Oreoluwa,

kernel test robot noticed the following build warnings:

[auto build test WARNING on robh/for-next]
[also build test WARNING on linus/master v6.16-rc6 next-20250718]
[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/Oreoluwa-Babatunde/of-reserved_mem-Restructure-call-site-for-dma_contiguous_early_fixup/20250719-074651
base:   https://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git for-next
patch link:    https://lore.kernel.org/r/20250718234504.2702128-1-oreoluwa.babatunde%40oss.qualcomm.com
patch subject: [PATCH v2] of: reserved_mem: Restructure call site for dma_contiguous_early_fixup()
config: i386-buildonly-randconfig-005-20250719 (https://download.01.org/0day-ci/archive/20250719/202507191943.suIkiLRK-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/20250719/202507191943.suIkiLRK-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/202507191943.suIkiLRK-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/of/of_reserved_mem.c:152:1: warning: no previous prototype for function 'dma_contiguous_early_fixup' [-Wmissing-prototypes]
     152 | dma_contiguous_early_fixup(phys_addr_t base, unsigned long size)
         | ^
   drivers/of/of_reserved_mem.c:151:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
     151 | void __weak
         | ^
         | static 
   1 warning generated.


vim +/dma_contiguous_early_fixup +152 drivers/of/of_reserved_mem.c

   150	
   151	void __weak
 > 152	dma_contiguous_early_fixup(phys_addr_t base, unsigned long size)
   153	{
   154	}
   155	

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

RE: [PATCH v2] of: reserved_mem: Restructure call site for dma_contiguous_early_fixup()

[William Zhang]

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> -----Original Message-----
> From: Oreoluwa Babatunde <oreoluwa.babatunde@oss.qualcomm.com>
> Sent: Friday, July 18, 2025 4:45 PM
> To: robh@kernel.org; m.szyprowski@samsung.com; robin.murphy@arm.com
> Cc: saravanak@google.com; quic_obabatun@quicinc.com;
> devicetree@vger.kernel.org; linux-kernel@vger.kernel.org;
> iommu@lists.linux.dev; william.zhang@broadcom.com;
> kernel@oss.qualcomm.com; will@kernel.org; djakov@kernel.org; Oreoluwa
> Babatunde <oreoluwa.babatunde@oss.qualcomm.com>
> Subject: [PATCH v2] of: reserved_mem: Restructure call site for
> dma_contiguous_early_fixup()
>
> Restructure the call site for dma_contiguous_early_fixup() to
> where the reserved_mem nodes are being parsed from the DT so that
> dma_mmu_remap[] is populated before dma_contiguous_remap() is called.
>
> Fixes: 8a6e02d0c00e ("of: reserved_mem: Restructure how the reserved
> memory regions are processed")
> Signed-off-by: Oreoluwa Babatunde
> <oreoluwa.babatunde@oss.qualcomm.com>
> ---
> v2: Add a check for the "reusable" property to narrow things down to
>     only cma regions.
>     Also add __weak function definition for dma_contiguous_early_fixup()
>     to avoid compile errors on architectures that do not define the
>     function.
>
>  drivers/of/of_reserved_mem.c | 21 ++++++++++++++++++---
>  kernel/dma/contiguous.c      |  2 --
>  2 files changed, 18 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
> index 77016c0cc296..eee96172883a 100644
> --- a/drivers/of/of_reserved_mem.c
> +++ b/drivers/of/of_reserved_mem.c
> @@ -25,6 +25,7 @@
>  #include <linux/memblock.h>
>  #include <linux/kmemleak.h>
>  #include <linux/cma.h>
> +#include <linux/dma-map-ops.h>
>
>  #include "of_private.h"
>
> @@ -147,6 +148,11 @@ static int __init
> early_init_dt_reserve_memory(phys_addr_t base,
>  	return memblock_reserve(base, size);
>  }
>
> +void __weak
> +dma_contiguous_early_fixup(phys_addr_t base, unsigned long size)
> +{
> +}
> +
>  /*
>   * __reserved_mem_reserve_reg() - reserve all memory described in 'reg'
> property
>   */
> @@ -175,13 +181,18 @@ static int __init
> __reserved_mem_reserve_reg(unsigned long node,
>  		base = dt_mem_next_cell(dt_root_addr_cells, &prop);
>  		size = dt_mem_next_cell(dt_root_size_cells, &prop);
>
> -		if (size &&
> -		    early_init_dt_reserve_memory(base, size, nomap) == 0)
> +		if (size && early_init_dt_reserve_memory(base, size,
nomap)
> == 0) {
> +			/* Architecture specific contiguous memory fixup.
*/
> +			if (of_flat_dt_is_compatible(node,
"shared-dma-pool")
> &&
> +			    of_get_flat_dt_prop(node, "reusable", NULL))
> +				dma_contiguous_early_fixup(base, size);
> +
>  			pr_debug("Reserved memory: reserved region for
node
> '%s': base %pa, size %lu MiB\n",
>  				uname, &base, (unsigned long)(size /
SZ_1M));
> -		else
> +		} else {
>  			pr_err("Reserved memory: failed to reserve memory
> for node '%s': base %pa, size %lu MiB\n",
>  			       uname, &base, (unsigned long)(size /
SZ_1M));
> +		}
>
>  		len -= t_len;
>  	}
> @@ -472,6 +483,10 @@ static int __init
> __reserved_mem_alloc_size(unsigned long node, const char *unam
>  		       uname, (unsigned long)(size / SZ_1M));
>  		return -ENOMEM;
>  	}
> +	/* Architecture specific contiguous memory fixup. */
> +	if (of_flat_dt_is_compatible(node, "shared-dma-pool") &&
> +	    of_get_flat_dt_prop(node, "reusable", NULL))
> +		dma_contiguous_early_fixup(base, size);
>
>  	/* Save region in the reserved_mem array */
>  	fdt_reserved_mem_save_node(node, uname, base, size);
> diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c
> index 67af8a55185d..d9b9dcba6ff7 100644
> --- a/kernel/dma/contiguous.c
> +++ b/kernel/dma/contiguous.c
> @@ -483,8 +483,6 @@ static int __init rmem_cma_setup(struct
> reserved_mem *rmem)
>  		pr_err("Reserved memory: unable to setup CMA region\n");
>  		return err;
>  	}
> -	/* Architecture specific contiguous memory fixup. */
> -	dma_contiguous_early_fixup(rmem->base, rmem->size);
>
>  	if (default_cma)
>  		dma_contiguous_default_area = cma;
> --
> 2.34.1

Tested-by: William Zhang <william.zhang@broadcom.com>

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