[PATCH RESEND] firmware: qemu_fw_cfg: Do not hard depend on CONFIG_HAS_IOPORT_MAP

[PATCH RESEND] firmware: qemu_fw_cfg: Do not hard depend on CONFIG_HAS_IOPORT_MAP

[Takashi Iwai]

From: Fabian Vogt <fvogt@suse.de>

Some platforms require CONFIG_NO_IOPORT_MAP=y but would also support
qemu_fw_cfg over MMIO. Currently the qemu_fw_cfg module can't be built for
those as it needs HAS_IOPORT_MAP=y for ioport remapping.

This patch allows to build the qemu_fw_cfg in those cases. If
CONFIG_HAS_IOPORT_MAP=n, qemu_fw_cfg is built without support for ioport
based access.

Signed-off-by: Fabian Vogt <fvogt@suse.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---

Resent, as the original submission seems overlooked:
 https://lore.kernel.org/2294036.ElGaqSPkdT@linux-e202.suse.de/
The patch has been on openSUSE / SUSE kernels already for years.

 drivers/firmware/Kconfig       | 1 -
 drivers/firmware/qemu_fw_cfg.c | 5 +++++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
index bbd2155d8483..91442f85f0f0 100644
--- a/drivers/firmware/Kconfig
+++ b/drivers/firmware/Kconfig
@@ -122,7 +122,6 @@ config RASPBERRYPI_FIRMWARE
 config FW_CFG_SYSFS
 	tristate "QEMU fw_cfg device support in sysfs"
 	depends on SYSFS && (ARM || ARM64 || PARISC || PPC_PMAC || RISCV || SPARC || X86)
-	depends on HAS_IOPORT_MAP
 	default n
 	help
 	  Say Y or M here to enable the exporting of the QEMU firmware
diff --git a/drivers/firmware/qemu_fw_cfg.c b/drivers/firmware/qemu_fw_cfg.c
index 2615fb780e3c..e15116f84a70 100644
--- a/drivers/firmware/qemu_fw_cfg.c
+++ b/drivers/firmware/qemu_fw_cfg.c
@@ -258,6 +258,7 @@ static int fw_cfg_do_platform_probe(struct platform_device *pdev)
 			return -EFAULT;
 		}
 	} else {
+#ifdef CONFIG_HAS_IOPORT_MAP
 		if (!request_region(fw_cfg_p_base,
 				    fw_cfg_p_size, "fw_cfg_io"))
 			return -EBUSY;
@@ -266,6 +267,10 @@ static int fw_cfg_do_platform_probe(struct platform_device *pdev)
 			release_region(fw_cfg_p_base, fw_cfg_p_size);
 			return -EFAULT;
 		}
+#else
+		dev_err(&pdev->dev, "IO region given but CONFIG_HAS_IOPORT_MAP=n");
+		return -EINVAL;
+#endif
 	}
 
 	/* were custom register offsets provided (e.g. on the command line)? */
-- 
2.49.0

Re: [PATCH RESEND] firmware: qemu_fw_cfg: Do not hard depend on CONFIG_HAS_IOPORT_MAP

[kernel test robot]

Hi Takashi,

kernel test robot noticed the following build errors:

[auto build test ERROR on linus/master]
[also build test ERROR on v6.16-rc2 next-20250617]
[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/Takashi-Iwai/firmware-qemu_fw_cfg-Do-not-hard-depend-on-CONFIG_HAS_IOPORT_MAP/20250617-001546
base:   linus/master
patch link:    https://lore.kernel.org/r/20250616161408.26748-1-tiwai%40suse.de
patch subject: [PATCH RESEND] firmware: qemu_fw_cfg: Do not hard depend on CONFIG_HAS_IOPORT_MAP
config: arm64-randconfig-r073-20250618 (https://download.01.org/0day-ci/archive/20250618/202506181300.OUXh1Amh-lkp@intel.com/config)
compiler: aarch64-linux-gcc (GCC) 9.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250618/202506181300.OUXh1Amh-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/202506181300.OUXh1Amh-lkp@intel.com/

All errors (new ones prefixed by >>):

   drivers/firmware/qemu_fw_cfg.c: In function 'fw_cfg_io_cleanup':
>> drivers/firmware/qemu_fw_cfg.c:207:3: error: implicit declaration of function 'ioport_unmap' [-Werror=implicit-function-declaration]
     207 |   ioport_unmap(fw_cfg_dev_base);
         |   ^~~~~~~~~~~~
   cc1: some warnings being treated as errors


vim +/ioport_unmap +207 drivers/firmware/qemu_fw_cfg.c

2d6d60a3d3eca5 Marc-André Lureau 2018-02-28  199  
75f3e8e47f3810 Gabriel Somlo     2016-01-28  200  /* clean up fw_cfg device i/o */
75f3e8e47f3810 Gabriel Somlo     2016-01-28  201  static void fw_cfg_io_cleanup(void)
75f3e8e47f3810 Gabriel Somlo     2016-01-28  202  {
75f3e8e47f3810 Gabriel Somlo     2016-01-28  203  	if (fw_cfg_is_mmio) {
75f3e8e47f3810 Gabriel Somlo     2016-01-28  204  		iounmap(fw_cfg_dev_base);
75f3e8e47f3810 Gabriel Somlo     2016-01-28  205  		release_mem_region(fw_cfg_p_base, fw_cfg_p_size);
75f3e8e47f3810 Gabriel Somlo     2016-01-28  206  	} else {
75f3e8e47f3810 Gabriel Somlo     2016-01-28 @207  		ioport_unmap(fw_cfg_dev_base);
75f3e8e47f3810 Gabriel Somlo     2016-01-28  208  		release_region(fw_cfg_p_base, fw_cfg_p_size);
75f3e8e47f3810 Gabriel Somlo     2016-01-28  209  	}
75f3e8e47f3810 Gabriel Somlo     2016-01-28  210  }
75f3e8e47f3810 Gabriel Somlo     2016-01-28  211  

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