[PATCH v3 1/5] hash.h: remove unused define directive

From: Isabella Basso
Date: Thu Oct 28 2021 - 18:32:15 EST


From: Isabella Basso <isabellabdoamaral@xxxxxx>

Currently, there exist hash_32() and __hash_32() functions, which were
introduced in a patch [1] targeting architecture specific optimizations.
These functions can be overridden on a per-architecture basis to achieve
such optimizations. They must set their corresponding define directive
(HAVE_ARCH_HASH_32 and HAVE_ARCH__HASH_32, respectively) so that header
files can deal with these overrides properly.

As the supported 32-bit architectures that have their own hash function
implementation (i.e. m68k, Microblaze, H8/300, pa-risc) have only been
making use of the (more general) __hash_32() function (which only lacks
a right shift operation when compared to the hash_32() function),
remove the define directive corresponding to the arch-specific hash_32()
implementation.

[1] https://lore.kernel.org/lkml/20160525073311.5600.qmail@xxxxxxxxxxxxxxxxxxxxxx/

Reviewed-by: David Gow <davidgow@xxxxxxxxxx>
Tested-by: David Gow <davidgow@xxxxxxxxxx>
Co-developed-by: Augusto Durães Camargo <augusto.duraes33@xxxxxxxxx>
Signed-off-by: Augusto Durães Camargo <augusto.duraes33@xxxxxxxxx>
Co-developed-by: Enzo Ferreira <ferreiraenzoa@xxxxxxxxx>
Signed-off-by: Enzo Ferreira <ferreiraenzoa@xxxxxxxxx>
Signed-off-by: Isabella Basso <isabbasso@xxxxxxxxxx>
---
Changes since v1:
- As suggested by David Gow:
1. Reword commit message.

include/linux/hash.h | 5 +----
lib/test_hash.c | 24 +-----------------------
tools/include/linux/hash.h | 5 +----
3 files changed, 3 insertions(+), 31 deletions(-)

diff --git a/include/linux/hash.h b/include/linux/hash.h
index ad6fa21d977b..38edaa08f862 100644
--- a/include/linux/hash.h
+++ b/include/linux/hash.h
@@ -62,10 +62,7 @@ static inline u32 __hash_32_generic(u32 val)
return val * GOLDEN_RATIO_32;
}

-#ifndef HAVE_ARCH_HASH_32
-#define hash_32 hash_32_generic
-#endif
-static inline u32 hash_32_generic(u32 val, unsigned int bits)
+static inline u32 hash_32(u32 val, unsigned int bits)
{
/* High bits are more random, so use them. */
return __hash_32(val) >> (32 - bits);
diff --git a/lib/test_hash.c b/lib/test_hash.c
index 0ee40b4a56dd..d4b0cfdb0377 100644
--- a/lib/test_hash.c
+++ b/lib/test_hash.c
@@ -94,22 +94,7 @@ test_int_hash(unsigned long long h64, u32 hash_or[2][33])
pr_err("hash_32(%#x, %d) = %#x > %#x", h0, k, h1, m);
return false;
}
-#ifdef HAVE_ARCH_HASH_32
- h2 = hash_32_generic(h0, k);
-#if HAVE_ARCH_HASH_32 == 1
- if (h1 != h2) {
- pr_err("hash_32(%#x, %d) = %#x != hash_32_generic() "
- " = %#x", h0, k, h1, h2);
- return false;
- }
-#else
- if (h2 > m) {
- pr_err("hash_32_generic(%#x, %d) = %#x > %#x",
- h0, k, h1, m);
- return false;
- }
-#endif
-#endif
+
/* Test hash_64 */
hash_or[1][k] |= h1 = hash_64(h64, k);
if (h1 > m) {
@@ -227,13 +212,6 @@ test_hash_init(void)
#else
pr_info("__hash_32() has no arch implementation to test.");
#endif
-#ifdef HAVE_ARCH_HASH_32
-#if HAVE_ARCH_HASH_32 != 1
- pr_info("hash_32() is arch-specific; not compared to generic.");
-#endif
-#else
- pr_info("hash_32() has no arch implementation to test.");
-#endif
#ifdef HAVE_ARCH_HASH_64
#if HAVE_ARCH_HASH_64 != 1
pr_info("hash_64() is arch-specific; not compared to generic.");
diff --git a/tools/include/linux/hash.h b/tools/include/linux/hash.h
index ad6fa21d977b..38edaa08f862 100644
--- a/tools/include/linux/hash.h
+++ b/tools/include/linux/hash.h
@@ -62,10 +62,7 @@ static inline u32 __hash_32_generic(u32 val)
return val * GOLDEN_RATIO_32;
}

-#ifndef HAVE_ARCH_HASH_32
-#define hash_32 hash_32_generic
-#endif
-static inline u32 hash_32_generic(u32 val, unsigned int bits)
+static inline u32 hash_32(u32 val, unsigned int bits)
{
/* High bits are more random, so use them. */
return __hash_32(val) >> (32 - bits);
--
2.33.1