[PATCH 1/2] firmware: arm_scmi: fix VIRTIO dependency

From: Arnd Bergmann <arnd@arndb.de>

Building with CONFIG_VIRTIO=m but CONFIG_ARM_SCMI_PROTOCOL=y leads to
a link error for the scmi virtio transport:

arm-linux-gnueabi-ld: drivers/firmware/arm_scmi/virtio.o: in function `virtio_send_message':
virtio.c:(.text+0x200): undefined reference to `virtqueue_add_sgs'
arm-linux-gnueabi-ld: virtio.c:(.text+0x280): undefined reference to `virtqueue_kick'
arm-linux-gnueabi-ld: drivers/firmware/arm_scmi/virtio.o: in function `scmi_vio_feed_vq_rx':
virtio.c:(.text+0x390): undefined reference to `virtqueue_add_inbuf'
arm-linux-gnueabi-ld: virtio.c:(.text+0x3dc): undefined reference to `virtqueue_kick'
arm-linux-gnueabi-ld: drivers/firmware/arm_scmi/virtio.o: in function `virtio_scmi_exit':
virtio.c:(.text+0x538): undefined reference to `unregister_virtio_driver'
arm-linux-gnueabi-ld: drivers/firmware/arm_scmi/virtio.o: in function `virtio_chan_available':

Prevent this configuration by making the Kconfig dependency a bit
stricter.

Fixes: 46abe13b5e3d ("firmware: arm_scmi: Add virtio transport")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/firmware/arm_scmi/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/firmware/arm_scmi/Kconfig b/drivers/firmware/arm_scmi/Kconfig
index 7f4d2435503b..3d7081e84853 100644
--- a/drivers/firmware/arm_scmi/Kconfig
+++ b/drivers/firmware/arm_scmi/Kconfig

@@ -68,7 +68,7 @@ config ARM_SCMI_TRANSPORT_SMC
 
 config ARM_SCMI_TRANSPORT_VIRTIO
 	bool "SCMI transport based on VirtIO"
-	depends on VIRTIO
+	depends on VIRTIO=y || VIRTIO=ARM_SCMI_PROTOCOL
 	select ARM_SCMI_HAVE_TRANSPORT
 	select ARM_SCMI_HAVE_MSG
 	help

-- 
2.29.2


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From: Arnd Bergmann <arnd@arndb.de>

virtio_scmi_exit() is only called from __exit function, so the annotation
is correct, but when the driver is built-in, the section gets discarded
and the reference from a callback pointer causes a link-time error:

`virtio_scmi_exit' referenced in section `.rodata' of drivers/firmware/arm_scmi/virtio.o: defined in discarded section `.exit.text' of drivers/firmware/arm_scmi/virtio.o

I could not figure out a better workaround, so let's just remove that
annotation even if it wastes a couple of bytes in .text.

Fixes: 46abe13b5e3d ("firmware: arm_scmi: Add virtio transport")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/firmware/arm_scmi/virtio.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/firmware/arm_scmi/virtio.c b/drivers/firmware/arm_scmi/virtio.c
index 224577f86928..8941bb40f2df 100644
--- a/drivers/firmware/arm_scmi/virtio.c
+++ b/drivers/firmware/arm_scmi/virtio.c

@@ -476,7 +476,7 @@ static int __init virtio_scmi_init(void)
 	return register_virtio_driver(&virtio_scmi_driver);
 }
 
-static void __exit virtio_scmi_exit(void)
+static void virtio_scmi_exit(void)
 {
 	unregister_virtio_driver(&virtio_scmi_driver);
 }

-- 
2.29.2


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On Mon, Sep 20, 2021 at 12:02:51PM +0200, Arnd Bergmann wrote:

From: Arnd Bergmann <arnd@arndb.de>

Building with CONFIG_VIRTIO=m but CONFIG_ARM_SCMI_PROTOCOL=y leads to
a link error for the scmi virtio transport:

arm-linux-gnueabi-ld: drivers/firmware/arm_scmi/virtio.o: in function `virtio_send_message':
virtio.c:(.text+0x200): undefined reference to `virtqueue_add_sgs'
arm-linux-gnueabi-ld: virtio.c:(.text+0x280): undefined reference to `virtqueue_kick'
arm-linux-gnueabi-ld: drivers/firmware/arm_scmi/virtio.o: in function `scmi_vio_feed_vq_rx':
virtio.c:(.text+0x390): undefined reference to `virtqueue_add_inbuf'
arm-linux-gnueabi-ld: virtio.c:(.text+0x3dc): undefined reference to `virtqueue_kick'
arm-linux-gnueabi-ld: drivers/firmware/arm_scmi/virtio.o: in function `virtio_scmi_exit':
virtio.c:(.text+0x538): undefined reference to `unregister_virtio_driver'
arm-linux-gnueabi-ld: drivers/firmware/arm_scmi/virtio.o: in function `virtio_chan_available':

Prevent this configuration by making the Kconfig dependency a bit
stricter.

Fixes: 46abe13b5e3d ("firmware: arm_scmi: Add virtio transport")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/firmware/arm_scmi/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Hi Arnd,

I have already queued similar fix by Cristain[1] a while ago. I was waiting
to get other possible fixes sorted before sending pull request. Sorry for
that, will do that soon.

-- 
Regards,
Sudeep

[1] https://lore.kernel.org/all/20210816141609.41751-1-cristian.marussi@arm.com/

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On Mon, Sep 20, 2021 at 12:02:52PM +0200, Arnd Bergmann wrote:

From: Arnd Bergmann <arnd@arndb.de>

virtio_scmi_exit() is only called from __exit function, so the annotation
is correct, but when the driver is built-in, the section gets discarded
and the reference from a callback pointer causes a link-time error:

`virtio_scmi_exit' referenced in section `.rodata' of drivers/firmware/arm_scmi/virtio.o: defined in discarded section `.exit.text' of drivers/firmware/arm_scmi/virtio.o

I could not figure out a better workaround, so let's just remove that
annotation even if it wastes a couple of bytes in .text.

[...]

Applied to sudeep.holla/linux (for-next/scmi), thanks!

[2/2] firmware: arm_scmi: remove __exit annotation
      https://git.kernel.org/sudeep.holla/c/1cd73200da

--
Regards,
Sudeep

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