The Google Coreboot implementation requires IOMEM functions
(memmremap, memunmap, devm_memremap), but does not specify this is its
Kconfig. This results in build errors when HAS_IOMEM is not set, such as
on some UML configurations:

/usr/bin/ld: drivers/firmware/google/coreboot_table.o: in function `coreboot_table_probe':
coreboot_table.c:(.text+0x311): undefined reference to `memremap'
/usr/bin/ld: coreboot_table.c:(.text+0x34e): undefined reference to `memunmap'
/usr/bin/ld: drivers/firmware/google/memconsole-coreboot.o: in function `memconsole_probe':
memconsole-coreboot.c:(.text+0x12d): undefined reference to `memremap'
/usr/bin/ld: memconsole-coreboot.c:(.text+0x17e): undefined reference to `devm_memremap'
/usr/bin/ld: memconsole-coreboot.c:(.text+0x191): undefined reference to `memunmap'
/usr/bin/ld: drivers/firmware/google/vpd.o: in function `vpd_section_destroy.isra.0':
vpd.c:(.text+0x300): undefined reference to `memunmap'
/usr/bin/ld: drivers/firmware/google/vpd.o: in function `vpd_section_init':
vpd.c:(.text+0x382): undefined reference to `memremap'
/usr/bin/ld: vpd.c:(.text+0x459): undefined reference to `memunmap'
/usr/bin/ld: drivers/firmware/google/vpd.o: in function `vpd_probe':
vpd.c:(.text+0x59d): undefined reference to `memremap'
/usr/bin/ld: vpd.c:(.text+0x5d3): undefined reference to `memunmap'
collect2: error: ld returned 1 exit status

Signed-off-by: David Gow <davidgow@google.com>
Acked-By: anton ivanov <anton.ivanov@cambridgegreys.com>
Acked-By: Julius Werner <jwerner@chromium.org>
---

Changes since v1:
http://lists.infradead.org/pipermail/linux-um/2022-February/002266.html
- Fix to depend on HAS_IOMEM, not IOMEM
- Add Acked-By tags.

---
 drivers/firmware/google/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/firmware/google/Kconfig b/drivers/firmware/google/Kconfig
index 931544c9f63d..983e07dc022e 100644
--- a/drivers/firmware/google/Kconfig
+++ b/drivers/firmware/google/Kconfig
@@ -21,7 +21,7 @@ config GOOGLE_SMI
 
 config GOOGLE_COREBOOT_TABLE
 	tristate "Coreboot Table Access"
-	depends on ACPI || OF
+	depends on HAS_IOMEM && (ACPI || OF)
 	help
 	  This option enables the coreboot_table module, which provides other
 	  firmware modules access to the coreboot table. The coreboot table
-- 
2.35.1.574.g5d30c73bfb-goog

On Fri, Feb 25, 2022 at 12:15:02PM +0800, David Gow wrote:
> The Google Coreboot implementation requires IOMEM functions
> (memmremap, memunmap, devm_memremap), but does not specify this is its
> Kconfig. This results in build errors when HAS_IOMEM is not set, such as
> on some UML configurations:
> 
> /usr/bin/ld: drivers/firmware/google/coreboot_table.o: in function `coreboot_table_probe':
> coreboot_table.c:(.text+0x311): undefined reference to `memremap'
> /usr/bin/ld: coreboot_table.c:(.text+0x34e): undefined reference to `memunmap'
> /usr/bin/ld: drivers/firmware/google/memconsole-coreboot.o: in function `memconsole_probe':
> memconsole-coreboot.c:(.text+0x12d): undefined reference to `memremap'
> /usr/bin/ld: memconsole-coreboot.c:(.text+0x17e): undefined reference to `devm_memremap'
> /usr/bin/ld: memconsole-coreboot.c:(.text+0x191): undefined reference to `memunmap'
> /usr/bin/ld: drivers/firmware/google/vpd.o: in function `vpd_section_destroy.isra.0':
> vpd.c:(.text+0x300): undefined reference to `memunmap'
> /usr/bin/ld: drivers/firmware/google/vpd.o: in function `vpd_section_init':
> vpd.c:(.text+0x382): undefined reference to `memremap'
> /usr/bin/ld: vpd.c:(.text+0x459): undefined reference to `memunmap'
> /usr/bin/ld: drivers/firmware/google/vpd.o: in function `vpd_probe':
> vpd.c:(.text+0x59d): undefined reference to `memremap'
> /usr/bin/ld: vpd.c:(.text+0x5d3): undefined reference to `memunmap'
> collect2: error: ld returned 1 exit status
> 
> Signed-off-by: David Gow <davidgow@google.com>
> Acked-By: anton ivanov <anton.ivanov@cambridgegreys.com>
> Acked-By: Julius Werner <jwerner@chromium.org>
> ---

What commit id does this fix?

thanks,

greg k-h

On Fri, Feb 25, 2022 at 6:47 PM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> On Fri, Feb 25, 2022 at 12:15:02PM +0800, David Gow wrote:
> > The Google Coreboot implementation requires IOMEM functions
> > (memmremap, memunmap, devm_memremap), but does not specify this is its
> > Kconfig. This results in build errors when HAS_IOMEM is not set, such as
> > on some UML configurations:
> >
> > /usr/bin/ld: drivers/firmware/google/coreboot_table.o: in function `coreboot_table_probe':
> > coreboot_table.c:(.text+0x311): undefined reference to `memremap'
> > /usr/bin/ld: coreboot_table.c:(.text+0x34e): undefined reference to `memunmap'
> > /usr/bin/ld: drivers/firmware/google/memconsole-coreboot.o: in function `memconsole_probe':
> > memconsole-coreboot.c:(.text+0x12d): undefined reference to `memremap'
> > /usr/bin/ld: memconsole-coreboot.c:(.text+0x17e): undefined reference to `devm_memremap'
> > /usr/bin/ld: memconsole-coreboot.c:(.text+0x191): undefined reference to `memunmap'
> > /usr/bin/ld: drivers/firmware/google/vpd.o: in function `vpd_section_destroy.isra.0':
> > vpd.c:(.text+0x300): undefined reference to `memunmap'
> > /usr/bin/ld: drivers/firmware/google/vpd.o: in function `vpd_section_init':
> > vpd.c:(.text+0x382): undefined reference to `memremap'
> > /usr/bin/ld: vpd.c:(.text+0x459): undefined reference to `memunmap'
> > /usr/bin/ld: drivers/firmware/google/vpd.o: in function `vpd_probe':
> > vpd.c:(.text+0x59d): undefined reference to `memremap'
> > /usr/bin/ld: vpd.c:(.text+0x5d3): undefined reference to `memunmap'
> > collect2: error: ld returned 1 exit status
> >
> > Signed-off-by: David Gow <davidgow@google.com>
> > Acked-By: anton ivanov <anton.ivanov@cambridgegreys.com>
> > Acked-By: Julius Werner <jwerner@chromium.org>
> > ---
>
> What commit id does this fix?
>
> thanks,
>
> greg k-h

As best I can tell, this[1] is the most sensible answer:

Fixes: a28aad66da ("firmware: coreboot: Collapse platform drivers into
bus core")

However, I think the first actual HAS_IOMEM-dependent calls were
introduced earlier, in "firmware: google memconsole: Add coreboot
support"[2], it just (a) never caused a problem under UML due to the
ACPI requirement, and (b) this fix won't apply particularly cleanly to
anything earlier than [1] anyway.

-- David

[1]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a28aad66da8bd19b249670d003bb9a698bdda397
[2]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=d384d6f43d1ec3f1225ab0275fd592c5980bd830