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From: Olaf Hering <olaf@aepfle.de>
To: xen-devel@lists.xenproject.org
Cc: Olaf Hering <olaf@aepfle.de>, Ian Jackson <iwj@xenproject.org>,
	Wei Liu <wl@xen.org>, Juergen Gross <jgross@suse.com>
Subject: [PATCH v20210713 03/31] tools: add API to work with sevaral bits at once
Date: Tue, 13 Jul 2021 20:05:37 +0200	[thread overview]
Message-ID: <20210713180605.12096-4-olaf@aepfle.de> (raw)
In-Reply-To: <20210713180605.12096-1-olaf@aepfle.de>

Introduce new API to test if a fixed number of bits is clear or set,
and clear or set them all at once.

The caller has to make sure the input bitnumber is a multiple of BITS_PER_LONG.

This API avoids the loop over each bit in a known range just to see
if all of them are either clear or set.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
---
v02:
- change return type from int to bool (jgross)
---
 tools/libs/ctrl/xc_bitops.h | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/tools/libs/ctrl/xc_bitops.h b/tools/libs/ctrl/xc_bitops.h
index f0bac4a071..8e8c6efb45 100644
--- a/tools/libs/ctrl/xc_bitops.h
+++ b/tools/libs/ctrl/xc_bitops.h
@@ -3,6 +3,7 @@
 
 /* bitmap operations for single threaded access */
 
+#include <stdbool.h>
 #include <stdlib.h>
 #include <string.h>
 
@@ -77,4 +78,31 @@ static inline void bitmap_or(void *_dst, const void *_other,
         dst[i] |= other[i];
 }
 
+static inline bool test_bit_long_set(unsigned long nr_base, const void *_addr)
+{
+    const unsigned long *addr = _addr;
+    unsigned long val = addr[nr_base / BITS_PER_LONG];
+
+    return val == ~0;
+}
+
+static inline bool test_bit_long_clear(unsigned long nr_base, const void *_addr)
+{
+    const unsigned long *addr = _addr;
+    unsigned long val = addr[nr_base / BITS_PER_LONG];
+
+    return val == 0;
+}
+
+static inline void clear_bit_long(unsigned long nr_base, void *_addr)
+{
+    unsigned long *addr = _addr;
+    addr[nr_base / BITS_PER_LONG] = 0;
+}
+
+static inline void set_bit_long(unsigned long nr_base, void *_addr)
+{
+    unsigned long *addr = _addr;
+    addr[nr_base / BITS_PER_LONG] = ~0;
+}
 #endif  /* XC_BITOPS_H */


  parent reply	other threads:[~2021-07-13 18:06 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-13 18:05 [PATCH v20210713 00/31] leftover from 2020 Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 01/31] tools: fix make rpmball Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 02/31] hotplug/Linux: fix starting of xenstored with restarting systemd Olaf Hering
2021-07-13 18:05 ` Olaf Hering [this message]
2021-07-13 18:05 ` [PATCH v20210713 04/31] xl: fix description of migrate --debug Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 05/31] tools: add readv_exact to libxenctrl Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 06/31] tools: show migration transfer rate in send_dirty_pages Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 07/31] tools: save: preallocate mfns array Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 08/31] tools: save: preallocate types array Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 09/31] tools: save: preallocate errors array Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 10/31] tools: save: preallocate iov array Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 11/31] tools: save: preallocate rec_pfns array Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 12/31] tools: save: preallocate guest_data array Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 13/31] tools: save: preallocate local_pages array Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 14/31] tools: restore: preallocate pfns array Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 15/31] tools: restore: preallocate types array Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 16/31] tools: restore: preallocate mfns array Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 17/31] tools: restore: preallocate map_errs array Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 18/31] tools: restore: preallocate populate_pfns pfns array Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 19/31] tools: restore: preallocate populate_pfns mfns array Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 20/31] tools: restore: split record processing Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 21/31] tools: restore: split handle_page_data Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 22/31] tools: restore: write data directly into guest Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 23/31] tools: recognize LIBXL_API_VERSION for 4.16 Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 24/31] tools: adjust libxl_domain_suspend to receive a struct props Olaf Hering
2021-07-13 18:05 ` [PATCH v20210713 25/31] tools: add callback to libxl for precopy_policy and precopy_stats Olaf Hering
2021-07-13 18:06 ` [PATCH v20210713 26/31] tools: add --max_iters to libxl_domain_suspend Olaf Hering
2021-07-13 18:06 ` [PATCH v20210713 27/31] tools: add --min_remaining " Olaf Hering
2021-07-13 18:06 ` [PATCH v20210713 28/31] tools: add --abort_if_busy " Olaf Hering
2021-07-13 18:06 ` [PATCH v20210713 29/31] tools: add API for expandable bitmaps Olaf Hering
2021-07-13 18:06 ` [PATCH v20210713 30/31] tools: use xg_sr_bitmap for populated_pfns Olaf Hering
2021-07-13 18:06 ` [PATCH v20210713 31/31] tools: use superpages during restore of HVM guest Olaf Hering

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