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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org,
	stable@vger.kernel.org
Cc: Helge Deller <deller@kernel.org>,
	Helge Deller <deller@gmx.de>,
	Kent Overstreet <kent.overstreet@linux.dev>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: [PATCH 6.7 611/713] bcachefs: Fix build on parisc by avoiding __multi3()
Date: Sun, 24 Mar 2024 18:45:37 -0400
Message-ID: <20240324224720.1345309-612-sashal@kernel.org>
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From: Helge Deller <deller@kernel.org>

commit eba38cc7578bef94865341c73608bdf49193a51d upstream.

The gcc compiler on paric does support the __int128 type, although the
architecture does not have native 128-bit support.

The effect is, that the bcachefs u128_square() function will pull in the
libgcc __multi3() helper, which breaks the kernel build when bcachefs is
built as module since this function isn't currently exported in
arch/parisc/kernel/parisc_ksyms.c.
The build failure can be seen in the latest debian kernel build at:
https://buildd.debian.org/status/fetch.php?pkg=linux&arch=hppa&ver=6.7.1-1%7Eexp1&stamp=1706132569&raw=0

We prefer to not export that symbol, so fall back to the optional 64-bit
implementation provided by bcachefs and thus avoid usage of __multi3().

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/bcachefs/mean_and_variance.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/bcachefs/mean_and_variance.h b/fs/bcachefs/mean_and_variance.h
index 647505010b397..056e797383fb5 100644
--- a/fs/bcachefs/mean_and_variance.h
+++ b/fs/bcachefs/mean_and_variance.h
@@ -14,7 +14,7 @@
  * type
  */
 
-#ifdef __SIZEOF_INT128__
+#if defined(__SIZEOF_INT128__) && defined(__KERNEL__) && !defined(CONFIG_PARISC)
 
 typedef struct {
 	unsigned __int128 v;
-- 
2.43.0