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From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: linux-kernel@vger.kernel.org,
	Thomas Gleixner <tglx@linutronix.de>,
	"Paul E . McKenney" <paulmck@kernel.org>,
	Boqun Feng <boqun.feng@gmail.com>,
	"H . Peter Anvin" <hpa@zytor.com>, Paul Turner <pjt@google.com>,
	linux-api@vger.kernel.org,
	Christian Brauner <christian.brauner@ubuntu.com>,
	Florian Weimer <fw@deneb.enyo.de>,
	David.Laight@ACULAB.COM, carlos@redhat.com,
	Peter Oskolkov <posk@posk.io>,
	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Subject: [PATCH v3 06/23] lib: invert _find_next_bit source arguments
Date: Fri, 29 Jul 2022 15:02:08 -0400	[thread overview]
Message-ID: <20220729190225.12726-7-mathieu.desnoyers@efficios.com> (raw)
In-Reply-To: <20220729190225.12726-1-mathieu.desnoyers@efficios.com>

Apply bit-invert operations before the AND operation in _find_next_bit.
Allows AND operations on combined bitmasks in which we search either for
one or zero, e.g.: find first bit which is both zero in one bitmask AND
one in the second bitmask.

The existing use for find first zero bit does not use the second
argument, so whether the inversion is performed before or after the AND
operator does not matter.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---
 include/linux/find.h       | 13 +++++++------
 lib/find_bit.c             | 17 ++++++++---------
 tools/include/linux/find.h |  9 +++++----
 tools/lib/find_bit.c       | 17 ++++++++---------
 4 files changed, 28 insertions(+), 28 deletions(-)

diff --git a/include/linux/find.h b/include/linux/find.h
index 5bb6db213bcb..41941cb9cad7 100644
--- a/include/linux/find.h
+++ b/include/linux/find.h
@@ -10,7 +10,8 @@
 
 extern unsigned long _find_next_bit(const unsigned long *addr1,
 		const unsigned long *addr2, unsigned long nbits,
-		unsigned long start, unsigned long invert, unsigned long le);
+		unsigned long start, unsigned long invert_src1,
+		unsigned long src2, unsigned long le);
 extern unsigned long _find_first_bit(const unsigned long *addr, unsigned long size);
 extern unsigned long _find_first_and_bit(const unsigned long *addr1,
 					 const unsigned long *addr2, unsigned long size);
@@ -41,7 +42,7 @@ unsigned long find_next_bit(const unsigned long *addr, unsigned long size,
 		return val ? __ffs(val) : size;
 	}
 
-	return _find_next_bit(addr, NULL, size, offset, 0UL, 0);
+	return _find_next_bit(addr, NULL, size, offset, 0UL, 0UL, 0);
 }
 #endif
 
@@ -71,7 +72,7 @@ unsigned long find_next_and_bit(const unsigned long *addr1,
 		return val ? __ffs(val) : size;
 	}
 
-	return _find_next_bit(addr1, addr2, size, offset, 0UL, 0);
+	return _find_next_bit(addr1, addr2, size, offset, 0UL, 0UL, 0);
 }
 #endif
 
@@ -99,7 +100,7 @@ unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size,
 		return val == ~0UL ? size : ffz(val);
 	}
 
-	return _find_next_bit(addr, NULL, size, offset, ~0UL, 0);
+	return _find_next_bit(addr, NULL, size, offset, ~0UL, 0UL, 0);
 }
 #endif
 
@@ -247,7 +248,7 @@ unsigned long find_next_zero_bit_le(const void *addr, unsigned
 		return val == ~0UL ? size : ffz(val);
 	}
 
-	return _find_next_bit(addr, NULL, size, offset, ~0UL, 1);
+	return _find_next_bit(addr, NULL, size, offset, ~0UL, 0UL, 1);
 }
 #endif
 
@@ -266,7 +267,7 @@ unsigned long find_next_bit_le(const void *addr, unsigned
 		return val ? __ffs(val) : size;
 	}
 
-	return _find_next_bit(addr, NULL, size, offset, 0UL, 1);
+	return _find_next_bit(addr, NULL, size, offset, 0UL, 0UL, 1);
 }
 #endif
 
diff --git a/lib/find_bit.c b/lib/find_bit.c
index 1b8e4b2a9cba..73e78565e691 100644
--- a/lib/find_bit.c
+++ b/lib/find_bit.c
@@ -25,23 +25,23 @@
 /*
  * This is a common helper function for find_next_bit, find_next_zero_bit, and
  * find_next_and_bit. The differences are:
- *  - The "invert" argument, which is XORed with each fetched word before
- *    searching it for one bits.
+ *  - The "invert_src1" and "invert_src2" arguments, which are XORed to
+ *    each source word before applying the 'and' operator.
  *  - The optional "addr2", which is anded with "addr1" if present.
  */
 unsigned long _find_next_bit(const unsigned long *addr1,
 		const unsigned long *addr2, unsigned long nbits,
-		unsigned long start, unsigned long invert, unsigned long le)
+		unsigned long start, unsigned long invert_src1,
+		unsigned long invert_src2, unsigned long le)
 {
 	unsigned long tmp, mask;
 
 	if (unlikely(start >= nbits))
 		return nbits;
 
-	tmp = addr1[start / BITS_PER_LONG];
+	tmp = addr1[start / BITS_PER_LONG] ^ invert_src1;
 	if (addr2)
-		tmp &= addr2[start / BITS_PER_LONG];
-	tmp ^= invert;
+		tmp &= addr2[start / BITS_PER_LONG] ^ invert_src2;
 
 	/* Handle 1st word. */
 	mask = BITMAP_FIRST_WORD_MASK(start);
@@ -57,10 +57,9 @@ unsigned long _find_next_bit(const unsigned long *addr1,
 		if (start >= nbits)
 			return nbits;
 
-		tmp = addr1[start / BITS_PER_LONG];
+		tmp = addr1[start / BITS_PER_LONG] ^ invert_src1;
 		if (addr2)
-			tmp &= addr2[start / BITS_PER_LONG];
-		tmp ^= invert;
+			tmp &= addr2[start / BITS_PER_LONG] ^ invert_src2;
 	}
 
 	if (le)
diff --git a/tools/include/linux/find.h b/tools/include/linux/find.h
index 47e2bd6c5174..5ab0c95086ad 100644
--- a/tools/include/linux/find.h
+++ b/tools/include/linux/find.h
@@ -10,7 +10,8 @@
 
 extern unsigned long _find_next_bit(const unsigned long *addr1,
 		const unsigned long *addr2, unsigned long nbits,
-		unsigned long start, unsigned long invert, unsigned long le);
+		unsigned long start, unsigned long invert_src1,
+		unsigned long src2, unsigned long le);
 extern unsigned long _find_first_bit(const unsigned long *addr, unsigned long size);
 extern unsigned long _find_first_and_bit(const unsigned long *addr1,
 					 const unsigned long *addr2, unsigned long size);
@@ -41,7 +42,7 @@ unsigned long find_next_bit(const unsigned long *addr, unsigned long size,
 		return val ? __ffs(val) : size;
 	}
 
-	return _find_next_bit(addr, NULL, size, offset, 0UL, 0);
+	return _find_next_bit(addr, NULL, size, offset, 0UL, 0UL, 0);
 }
 #endif
 
@@ -71,7 +72,7 @@ unsigned long find_next_and_bit(const unsigned long *addr1,
 		return val ? __ffs(val) : size;
 	}
 
-	return _find_next_bit(addr1, addr2, size, offset, 0UL, 0);
+	return _find_next_bit(addr1, addr2, size, offset, 0UL, 0UL, 0);
 }
 #endif
 
@@ -99,7 +100,7 @@ unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size,
 		return val == ~0UL ? size : ffz(val);
 	}
 
-	return _find_next_bit(addr, NULL, size, offset, ~0UL, 0);
+	return _find_next_bit(addr, NULL, size, offset, ~0UL, 0UL, 0);
 }
 #endif
 
diff --git a/tools/lib/find_bit.c b/tools/lib/find_bit.c
index ba4b8d94e004..4176232de7f9 100644
--- a/tools/lib/find_bit.c
+++ b/tools/lib/find_bit.c
@@ -24,13 +24,14 @@
 /*
  * This is a common helper function for find_next_bit, find_next_zero_bit, and
  * find_next_and_bit. The differences are:
- *  - The "invert" argument, which is XORed with each fetched word before
- *    searching it for one bits.
+ *  - The "invert_src1" and "invert_src2" arguments, which are XORed to
+ *    each source word before applying the 'and' operator.
  *  - The optional "addr2", which is anded with "addr1" if present.
  */
 unsigned long _find_next_bit(const unsigned long *addr1,
 		const unsigned long *addr2, unsigned long nbits,
-		unsigned long start, unsigned long invert, unsigned long le)
+		unsigned long start, unsigned long invert_src1,
+		unsigned long invert_src2, unsigned long le)
 {
 	unsigned long tmp, mask;
 	(void) le;
@@ -38,10 +39,9 @@ unsigned long _find_next_bit(const unsigned long *addr1,
 	if (unlikely(start >= nbits))
 		return nbits;
 
-	tmp = addr1[start / BITS_PER_LONG];
+	tmp = addr1[start / BITS_PER_LONG] ^ invert_src1;
 	if (addr2)
-		tmp &= addr2[start / BITS_PER_LONG];
-	tmp ^= invert;
+		tmp &= addr2[start / BITS_PER_LONG] ^ invert_src2;
 
 	/* Handle 1st word. */
 	mask = BITMAP_FIRST_WORD_MASK(start);
@@ -64,10 +64,9 @@ unsigned long _find_next_bit(const unsigned long *addr1,
 		if (start >= nbits)
 			return nbits;
 
-		tmp = addr1[start / BITS_PER_LONG];
+		tmp = addr1[start / BITS_PER_LONG] ^ invert_src1;
 		if (addr2)
-			tmp &= addr2[start / BITS_PER_LONG];
-		tmp ^= invert;
+			tmp &= addr2[start / BITS_PER_LONG] ^ invert_src2;
 	}
 
 #if (0)
-- 
2.17.1


  parent reply	other threads:[~2022-07-29 19:03 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-07-29 19:02 [PATCH v3 00/23] RSEQ node id and virtual cpu id extensions Mathieu Desnoyers
2022-07-29 19:02 ` [PATCH v3 01/23] rseq: Introduce feature size and alignment ELF auxiliary vector entries Mathieu Desnoyers
2022-07-29 19:02 ` [PATCH v3 02/23] rseq: Introduce extensible rseq ABI Mathieu Desnoyers
2022-08-10  6:33   ` Florian Weimer
2022-08-10 13:27     ` Mathieu Desnoyers
2022-07-29 19:02 ` [PATCH v3 03/23] rseq: extend struct rseq with numa node id Mathieu Desnoyers
2022-07-29 19:02 ` [PATCH v3 04/23] selftests/rseq: Use ELF auxiliary vector for extensible rseq Mathieu Desnoyers
2022-07-29 19:02 ` [PATCH v3 05/23] selftests/rseq: Implement rseq numa node id field selftest Mathieu Desnoyers
2022-07-29 19:02 ` Mathieu Desnoyers [this message]
2022-07-29 19:02 ` [PATCH v3 07/23] lib: implement find_{first,next}_{zero,one}_and_zero_bit Mathieu Desnoyers
2022-07-29 19:02 ` [PATCH v3 08/23] cpumask: implement cpumask_{first,next}_{zero,one}_and_zero Mathieu Desnoyers
2022-07-29 19:02 ` [PATCH v3 09/23] sched: Introduce per memory space current virtual cpu id Mathieu Desnoyers
2022-07-29 19:02 ` [PATCH v3 10/23] rseq: extend struct rseq with per memory space vcpu id Mathieu Desnoyers
2022-07-29 19:02 ` [PATCH v3 11/23] selftests/rseq: Remove RSEQ_SKIP_FASTPATH code Mathieu Desnoyers
2022-07-29 19:02 ` [PATCH v3 12/23] selftests/rseq: Implement rseq vm_vcpu_id field support Mathieu Desnoyers
2022-07-29 19:02 ` [PATCH v3 13/23] selftests/rseq: x86: Template memory ordering and percpu access mode Mathieu Desnoyers
2022-07-29 19:02 ` [PATCH v3 14/23] selftests/rseq: arm: " Mathieu Desnoyers
2022-07-29 19:02 ` [PATCH v3 15/23] selftests/rseq: arm64: " Mathieu Desnoyers
2022-07-29 19:02 ` [PATCH v3 16/23] selftests/rseq: mips: " Mathieu Desnoyers
2022-07-29 19:02 ` [PATCH v3 17/23] selftests/rseq: ppc: " Mathieu Desnoyers
2022-07-29 19:02 ` [PATCH v3 18/23] selftests/rseq: s390: " Mathieu Desnoyers
2022-07-29 19:02 ` [PATCH v3 19/23] selftests/rseq: riscv: " Mathieu Desnoyers
2022-07-29 19:02 ` [PATCH v3 20/23] selftests/rseq: basic percpu ops vm_vcpu_id test Mathieu Desnoyers
2022-07-29 19:02 ` [PATCH v3 21/23] selftests/rseq: parametrized " Mathieu Desnoyers
2022-07-29 19:02 ` [PATCH v3 22/23] selftests/rseq: x86: Implement rseq_load_u32_u32 Mathieu Desnoyers
2022-07-29 19:02 ` [PATCH v3 23/23] selftests/rseq: Implement numa node id vs vm_vcpu_id invariant test Mathieu Desnoyers
2022-08-01 17:07 ` [PATCH v3 00/23] RSEQ node id and virtual cpu id extensions Peter Oskolkov
2022-08-02 15:01   ` Mathieu Desnoyers
2022-08-02 17:06     ` Peter Oskolkov
2022-08-02 20:53       ` Mathieu Desnoyers
2022-08-04 16:18         ` Chris Kennelly

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