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: [RFC PATCH v2 07/11] lib: implement find_{first,next}_{zero,one}_and_zero_bit
Date: Fri, 18 Feb 2022 16:06:29 -0500 [thread overview]
Message-ID: <20220218210633.23345-8-mathieu.desnoyers@efficios.com> (raw)
In-Reply-To: <20220218210633.23345-1-mathieu.desnoyers@efficios.com>
Allow finding the first or next bit within two input bitmasks which is
either:
- both zero and zero,
- respectively one and zero.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---
include/linux/find.h | 110 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 110 insertions(+)
diff --git a/include/linux/find.h b/include/linux/find.h
index 41941cb9cad7..9b6edd00b45e 100644
--- a/include/linux/find.h
+++ b/include/linux/find.h
@@ -76,6 +76,66 @@ unsigned long find_next_and_bit(const unsigned long *addr1,
}
#endif
+#ifndef find_next_one_and_zero_bit
+/**
+ * find_next_one_and_zero_bit - find the next bit which is one in addr1 and zero in addr2
+ * @addr1: The first address to base the search on
+ * @addr2: The second address to base the search on
+ * @offset: The bitnumber to start searching at
+ * @size: The bitmap size in bits
+ *
+ * Returns the bit number for the next bit set in addr1 and cleared in addr2
+ * If no corresponding bits meet this criterion, returns @size.
+ */
+static inline
+unsigned long find_next_one_and_zero_bit(const unsigned long *addr1,
+ const unsigned long *addr2, unsigned long size,
+ unsigned long offset)
+{
+ if (small_const_nbits(size)) {
+ unsigned long val;
+
+ if (unlikely(offset >= size))
+ return size;
+
+ val = *addr1 & ~*addr2 & GENMASK(size - 1, offset);
+ return val ? __ffs(val) : size;
+ }
+
+ return _find_next_bit(addr1, addr2, size, offset, 0UL, ~0UL, 0);
+}
+#endif
+
+#ifndef find_next_zero_and_zero_bit
+/**
+ * find_next_zero_and_zero_bit - find the next bit which is zero in addr1 and addr2
+ * @addr1: The first address to base the search on
+ * @addr2: The second address to base the search on
+ * @offset: The bitnumber to start searching at
+ * @size: The bitmap size in bits
+ *
+ * Returns the bit number for the next bit cleared in addr1 and addr2
+ * If no corresponding bits meet this criterion, returns @size.
+ */
+static inline
+unsigned long find_next_zero_and_zero_bit(const unsigned long *addr1,
+ const unsigned long *addr2, unsigned long size,
+ unsigned long offset)
+{
+ if (small_const_nbits(size)) {
+ unsigned long val;
+
+ if (unlikely(offset >= size))
+ return size;
+
+ val = ~*addr1 & ~*addr2 & GENMASK(size - 1, offset);
+ return val ? __ffs(val) : size;
+ }
+
+ return _find_next_bit(addr1, addr2, size, offset, ~0UL, ~0UL, 0);
+}
+#endif
+
#ifndef find_next_zero_bit
/**
* find_next_zero_bit - find the next cleared bit in a memory region
@@ -173,6 +233,56 @@ unsigned long find_first_zero_bit(const unsigned long *addr, unsigned long size)
}
#endif
+#ifndef find_first_one_and_zero_bit
+/**
+ * find_first_one_and_zero_bit - find the first bit which is one in addr1 and zero in addr2
+ * @addr1: The first address to base the search on
+ * @addr2: The second address to base the search on
+ * @size: The bitmap size in bits
+ *
+ * Returns the bit number for the first bit set in addr1 and cleared in addr2
+ * If no corresponding bits meet this criterion, returns @size.
+ */
+static inline
+unsigned long find_first_one_and_zero_bit(const unsigned long *addr1,
+ const unsigned long *addr2,
+ unsigned long size)
+{
+ if (small_const_nbits(size)) {
+ unsigned long val = *addr1 & ~*addr2 & GENMASK(size - 1, 0);
+
+ return val ? __ffs(val) : size;
+ }
+
+ return _find_next_bit(addr1, addr2, size, 0, 0UL, ~0UL, 0);
+}
+#endif
+
+#ifndef find_first_zero_and_zero_bit
+/**
+ * find_first_zero_and_zero_bit - find the first bit which is zero in addr1 and addr2
+ * @addr1: The first address to base the search on
+ * @addr2: The second address to base the search on
+ * @size: The bitmap size in bits
+ *
+ * Returns the bit number for the first bit cleared in addr1 and addr2
+ * If no corresponding bits meet this criterion, returns @size.
+ */
+static inline
+unsigned long find_first_zero_and_zero_bit(const unsigned long *addr1,
+ const unsigned long *addr2,
+ unsigned long size)
+{
+ if (small_const_nbits(size)) {
+ unsigned long val = ~*addr1 & ~*addr2 & GENMASK(size - 1, 0);
+
+ return val ? __ffs(val) : size;
+ }
+
+ return _find_next_bit(addr1, addr2, size, 0, ~0UL, ~0UL, 0);
+}
+#endif
+
#ifndef find_last_bit
/**
* find_last_bit - find the last set bit in a memory region
--
2.17.1
next prev parent reply other threads:[~2022-02-18 21:16 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-18 21:06 [RFC PATCH v2 00/11] RSEQ node id and virtual cpu id extensions Mathieu Desnoyers
2022-02-18 21:06 ` [RFC PATCH v2 01/11] rseq: Introduce feature size and alignment ELF auxiliary vector entries Mathieu Desnoyers
2022-02-18 21:06 ` [RFC PATCH v2 02/11] rseq: Introduce extensible rseq ABI Mathieu Desnoyers
2022-02-18 21:06 ` [RFC PATCH v2 03/11] rseq: extend struct rseq with numa node id Mathieu Desnoyers
2022-02-18 21:06 ` [RFC PATCH v2 04/11] selftests/rseq: Use ELF auxiliary vector for extensible rseq Mathieu Desnoyers
2022-02-18 21:06 ` [RFC PATCH v2 05/11] selftests/rseq: Implement rseq numa node id field selftest Mathieu Desnoyers
2022-02-18 21:06 ` [RFC PATCH v2 06/11] lib: invert _find_next_bit source arguments Mathieu Desnoyers
2022-02-18 21:06 ` Mathieu Desnoyers [this message]
2022-02-18 21:06 ` [RFC PATCH v2 08/11] cpumask: implement cpumask_{first,next}_{zero,one}_and_zero Mathieu Desnoyers
2022-02-18 21:06 ` [RFC PATCH v2 09/11] sched: Introduce per memory space current virtual cpu id Mathieu Desnoyers
2022-02-21 17:38 ` [RFC PATCH v3 " Mathieu Desnoyers
2022-02-25 17:35 ` [RFC PATCH v2 " Jonathan Corbet
2022-02-25 17:56 ` Mathieu Desnoyers
2022-02-25 18:15 ` Jonathan Corbet
2022-02-25 18:39 ` Mathieu Desnoyers
2022-02-25 19:24 ` Jonathan Corbet
2022-02-25 21:21 ` Mathieu Desnoyers
2022-02-18 21:06 ` [RFC PATCH v2 10/11] rseq: extend struct rseq with per memory space vcpu id Mathieu Desnoyers
2022-02-18 21:06 ` [RFC PATCH v2 11/11] selftests/rseq: Implement rseq vm_vcpu_id field support Mathieu Desnoyers
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