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From: Charlie Jenkins <charlie@rivosinc.com>
Date: Wed, 21 Feb 2024 18:37:13 -0800
Subject: [PATCH 3/4] parisc: checksum: Remove folding from csum_partial
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Message-Id: <20240221-parisc_use_generic_checksum-v1-3-ad34d895fd1b@rivosinc.com>
References: <20240221-parisc_use_generic_checksum-v1-0-ad34d895fd1b@rivosinc.com>
In-Reply-To: <20240221-parisc_use_generic_checksum-v1-0-ad34d895fd1b@rivosinc.com>
To: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>, 
 Helge Deller <deller@gmx.de>, Arnd Bergmann <arnd@arndb.de>, 
 Andrew Morton <akpm@linux-foundation.org>, 
 Guenter Roeck <linux@roeck-us.net>
Cc: linux-parisc@vger.kernel.org, linux-kernel@vger.kernel.org, 
 linux-arch@vger.kernel.org, Charlie Jenkins <charlie@rivosinc.com>

The parisc implementation of csum_partial previously folded the result
into 16 bits instead of returning all 32 bits and letting consumers like
ip_compute_csum do the folding. Since ip_compute_csum no longer depends
on this requirement, remove the folding so that the parisc
implementation operates the same as other architectures.

Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
---
 arch/parisc/lib/checksum.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/arch/parisc/lib/checksum.c b/arch/parisc/lib/checksum.c
index 05f5ca4b2f96..eaa660491e24 100644
--- a/arch/parisc/lib/checksum.c
+++ b/arch/parisc/lib/checksum.c
@@ -95,14 +95,11 @@ unsigned int do_csum(const unsigned char *buff, int len)
 /*
  * computes a partial checksum, e.g. for TCP/UDP fragments
  */
-/*
- * why bother folding?
- */
 __wsum csum_partial(const void *buff, int len, __wsum sum)
 {
 	unsigned int result = do_csum(buff, len);
 	addc(result, sum);
-	return (__force __wsum)from32to16(result);
+	return (__force __wsum)result;
 }
 
 EXPORT_SYMBOL(csum_partial);

-- 
2.34.1