can: mscan: replace in_8/out_8 with ioread8/iowrite8

PATCH In review Rosen Penev 2 participants 4 messages Jun 2 – Jun 3 CAN network drivers

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Rosen Penev

author

2026-06-02 22:34 UTC #0 lore raw

PATCH 1/1 can: mscan: replace in_8/out_8 with ioread8/iowrite8

Mechanical conversion of the ppc4xx-specific in_8/out_8 accessors and the setbits8/clrbits8 macros to the generic ioread8/iowrite8 helpers for portability.

Add HAS_IOMEM as these functions need it.

Add COMPILE_TEST as a result. This can be built anywhere now.

Assisted-by opencode:big-pickle

Signed-off-by Rosen Penev <[email protected]>

---
 drivers/net/can/mscan/Kconfig |   3 +-
 drivers/net/can/mscan/mscan.c | 143 +++++++++++++++++-----------------
 2 files changed, 73 insertions(+), 73 deletions(-)

drivers/net/can/mscan/Kconfig +2 -1

index dfe6bd9947bb..ef3a99b3d3db 100644
@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0-only
 config CAN_MSCAN
-	depends on PPC
+	depends on PPC || COMPILE_TEST
+	depends on HAS_IOMEM
 	tristate "Support for Freescale MSCAN based chips"
 	help
 	  The Motorola Scalable Controller Area Network (MSCAN) definition

drivers/net/can/mscan/mscan.c +71 ~~-72~~

373 lines not on this page · raw message

Signature · 1 line

2.54.0

Rosen Penev

author

2026-06-03 00:43 UTC #2 lore raw

Quoted 22 lines · Vincent Mailhol

Quoted 10 lines · Rosen Penev
Mechanical conversion of the ppc4xx-specific in_8/out_8 accessors and the setbits8/clrbits8 macros to the generic ioread8/iowrite8 helpers for portability.
Add HAS_IOMEM as these functions need it.
Add COMPILE_TEST as a result. This can be built anywhere now.
Assisted-by opencode:big-pickle
Signed-off-by Rosen Penev <[email protected]>
I left a comment for a potential extension of the patch, but it is ok as-is.
Reviewed-by Vincent Mailhol <[email protected]>
Quoted 5 lines
---
 drivers/net/can/mscan/Kconfig |   3 +-
 drivers/net/can/mscan/mscan.c | 143 +++++++++++++++++-----------------
 2 files changed, 73 insertions(+), 73 deletions(-)

Quoted 13 lines

drivers/net/can/mscan/Kconfig line 4
Quoted 10 lines
drivers/net/can/mscan/Kconfig +2 -1
index dfe6bd9947bb..ef3a99b3d3db 100644
@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0-only
 config CAN_MSCAN
-     depends on PPC
+     depends on PPC || COMPILE_TEST
+     depends on HAS_IOMEM
It seems to me that following your changes, it should also now become easy to add COMPILE_TEST to config CAN_MPC5XXX.

I'll look into this.

Quoted 46 lines

mpc5xxx_can.c has a couple of unused headers, after removing those, I could compile test it!

These are my local changes:

----8<----

drivers/net/can/mscan/Kconfig +1 -1

index ef3a99b3d3db..9bffd91ea418 100644
@@ -13,7 +13,7 @@ if CAN_MSCAN
 
 config CAN_MPC5XXX
        tristate "Freescale MPC5xxx onboard CAN controller"
-       depends on (PPC_MPC52xx || PPC_MPC512x)
+       depends on PPC_MPC52xx || PPC_MPC512x || COMPILE_TEST
        help
          If you say yes here you get support for Freescale's MPC5xxx
          onboard CAN controller. Currently, the MPC5200, MPC5200B and

drivers/net/can/mscan/mpc5xxx_can.c +0 -8

index 0080c39ee182..759efb71d843 100644
@@ -9,8 +9,6 @@
  */
 
 #include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/interrupt.h>
 #include <linux/platform_device.h>
 #include <linux/property.h>
 #include <linux/netdevice.h>

@@ -18,11 +16,6 @@
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
-#include <linux/of_platform.h>
-#include <sysdev/fsl_soc.h>
-#include <linux/clk.h>
-#include <linux/io.h>
-#include <asm/mpc52xx.h>
 
 #include "mscan.h"
----8<----

Quoted 1 line

Et voilà ! Both CAN_MSCAN and CAN_MPC5XXX can now be compile tested!

drivers/net/can/mscan/mpc5xxx_can.c:22:10: fatal error:
'sysdev/fsl_soc.h' file not found 22 | #include <sysdev/fsl_soc.h> | ^~~~~~~~~~~~~~~~~~

drivers/net/can/mscan/mpc5xxx_can.c:376:2: error: call to undeclared function '_memcpy_fromio'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration] 376 | _memcpy_fromio(&saved_regs, regs, sizeof(*regs)); | ^

needs more work.

Quoted 10 lines

drivers/net/can/mscan/Kconfig line 7
Quoted 5 lines
drivers/net/can/mscan/Kconfig +0 -0
      tristate "Support for Freescale MSCAN based chips"
      help
        The Motorola Scalable Controller Area Network (MSCAN) definition
Yours sincerely,
Vincent Mailhol

Vincent Mailhol

maintainer

2026-06-03 11:31 UTC #3 lore raw

Quoted 88 lines · Rosen Penev

Quoted 22 lines · Vincent Mailhol
Quoted 10 lines · Rosen Penev
Mechanical conversion of the ppc4xx-specific in_8/out_8 accessors and the setbits8/clrbits8 macros to the generic ioread8/iowrite8 helpers for portability.
Add HAS_IOMEM as these functions need it.
Add COMPILE_TEST as a result. This can be built anywhere now.
Assisted-by opencode:big-pickle
Signed-off-by Rosen Penev <[email protected]>
I left a comment for a potential extension of the patch, but it is ok as-is.
Reviewed-by Vincent Mailhol <[email protected]>
Quoted 5 lines
---
 drivers/net/can/mscan/Kconfig |   3 +-
 drivers/net/can/mscan/mscan.c | 143 +++++++++++++++++-----------------
 2 files changed, 73 insertions(+), 73 deletions(-)
Quoted 13 lines
drivers/net/can/mscan/Kconfig line 4
Quoted 10 lines
drivers/net/can/mscan/Kconfig +2 -1
index dfe6bd9947bb..ef3a99b3d3db 100644
@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0-only
 config CAN_MSCAN
-     depends on PPC
+     depends on PPC || COMPILE_TEST
+     depends on HAS_IOMEM
It seems to me that following your changes, it should also now become easy to add COMPILE_TEST to config CAN_MPC5XXX.
I'll look into this.
Quoted 46 lines
mpc5xxx_can.c has a couple of unused headers, after removing those, I could compile test it!
These are my local changes:
----8<----
drivers/net/can/mscan/Kconfig +1 -1
index ef3a99b3d3db..9bffd91ea418 100644
@@ -13,7 +13,7 @@ if CAN_MSCAN
 
 config CAN_MPC5XXX
        tristate "Freescale MPC5xxx onboard CAN controller"
-       depends on (PPC_MPC52xx || PPC_MPC512x)
+       depends on PPC_MPC52xx || PPC_MPC512x || COMPILE_TEST
        help
          If you say yes here you get support for Freescale's MPC5xxx
          onboard CAN controller. Currently, the MPC5200, MPC5200B and
drivers/net/can/mscan/mpc5xxx_can.c +0 -8
index 0080c39ee182..759efb71d843 100644
@@ -9,8 +9,6 @@
  */
 
 #include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/interrupt.h>
 #include <linux/platform_device.h>
 #include <linux/property.h>
 #include <linux/netdevice.h>
@@ -18,11 +16,6 @@
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
-#include <linux/of_platform.h>
-#include <sysdev/fsl_soc.h>
-#include <linux/clk.h>
-#include <linux/io.h>
-#include <asm/mpc52xx.h>
 
 #include "mscan.h"
----8<----
Quoted 1 line
Et voilà ! Both CAN_MSCAN and CAN_MPC5XXX can now be compile tested!
drivers/net/can/mscan/mpc5xxx_can.c:22:10: fatal error:
'sysdev/fsl_soc.h' file not found 22 | #include <sysdev/fsl_soc.h> | ^~~~~~~~~~~~~~~~~~

Quoted 6 lines

drivers/net/can/mscan/mpc5xxx_can.c:376:2: error: call to undeclared function '_memcpy_fromio'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration] 376 | _memcpy_fromio(&saved_regs, regs, sizeof(*regs)); | ^
needs more work.

Ah! I only compiled the objects but didn't link them and thus missed this error. Well, this is what I get for answering the mailing list in the middle of the night.

Regardless, for PPC, memcpy_toio() and _memcpy_toio() are the exact same function and memcpy_fromio() is implemented as:

	#ifdef CONFIG_EEH
	#define __do_memcpy_fromio(dst, src, n)	\
					eeh_memcpy_fromio(dst, src, n)
	#else /* CONFIG_EEH */
	#define __do_memcpy_fromio(dst, src, n)	\
					_memcpy_fromio(dst, src, n)
	#endif /* !CONFIG_EEH */
	
	static inline void memcpy_fromio(void *d, const volatile void __iomem *s, unsigned long n)
	{
		__do_memcpy_fromio(d, s, n);
	}

So also the same as _memcpy_fromio() if CONFIG_EEH is not selected. And if CONFIG_EEH is selected, using _memcpy_fromio() instead of eeh_memcpy_fromio() seems incorrect.

I think that the final nail in the curtain is that mpc5xxx is the only driver in the full tree still using _memcpy_fromio() and _memcpy_toio().

After replacing both with their memcpy_fromio() and memcpy_toio() equivalent, I can now build and link without any problem on non PPC architectures.

Quoted 3 lines

Quoted 3 lines
drivers/net/can/mscan/Kconfig line 7
Quoted 3 lines
drivers/net/can/mscan/Kconfig +0 -0
      tristate "Support for Freescale MSCAN based chips"
      help
        The Motorola Scalable Controller Area Network (MSCAN) definition

Yours sincerely,
Vincent Mailhol