forked from SLFO-pool/xen
65 lines
1.7 KiB
Diff
65 lines
1.7 KiB
Diff
From: Olaf Hering <olaf@aepfle.de>
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Date: Wed, 9 Dec 2020 16:40:00 +0100
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Subject: libxc sr bitmap long
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tools: add API to work with sevaral bits at once
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Introduce new API to test if a fixed number of bits is clear or set,
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and clear or set them all at once.
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The caller has to make sure the input bitnumber is a multiple of BITS_PER_LONG.
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This API avoids the loop over each bit in a known range just to see
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if all of them are either clear or set.
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Signed-off-by: Olaf Hering <olaf@aepfle.de>
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v02:
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- change return type from int to bool (jgross)
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---
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tools/libs/ctrl/xc_bitops.h | 28 ++++++++++++++++++++++++++++
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1 file changed, 28 insertions(+)
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--- a/tools/libs/ctrl/xc_bitops.h
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+++ b/tools/libs/ctrl/xc_bitops.h
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@@ -3,6 +3,7 @@
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/* bitmap operations for single threaded access */
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+#include <stdbool.h>
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#include <stdlib.h>
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#include <string.h>
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@@ -81,4 +82,31 @@ static inline void bitmap_or(void *_dst,
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dst[i] |= other[i];
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}
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+static inline bool test_bit_long_set(unsigned long nr_base, const void *_addr)
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+{
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+ const unsigned long *addr = _addr;
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+ unsigned long val = addr[nr_base / BITS_PER_LONG];
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+
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+ return val == ~0;
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+}
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+
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+static inline bool test_bit_long_clear(unsigned long nr_base, const void *_addr)
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+{
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+ const unsigned long *addr = _addr;
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+ unsigned long val = addr[nr_base / BITS_PER_LONG];
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+
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+ return val == 0;
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+}
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+
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+static inline void clear_bit_long(unsigned long nr_base, void *_addr)
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+{
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+ unsigned long *addr = _addr;
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+ addr[nr_base / BITS_PER_LONG] = 0;
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+}
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+
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+static inline void set_bit_long(unsigned long nr_base, void *_addr)
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+{
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+ unsigned long *addr = _addr;
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+ addr[nr_base / BITS_PER_LONG] = ~0;
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+}
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#endif /* XC_BITOPS_H */
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