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authorLinus Torvalds <torvalds@linux-foundation.org>2013-11-08 08:24:38 +0900
committerLinus Torvalds <torvalds@linux-foundation.org>2013-11-08 08:24:38 +0900
commit280c84d1c1726be7ada045735858acdc8cfdd65a (patch)
treeb9afa3fb97b08272b6952d5c8d1fe31f6a8092fa /arch/s390/lib/find.c
parent8efdf2b759409f85953b84d52a14ea4d39c80474 (diff)
parentde9587a2f54d2d0063f0dbc775328129b9daaaa2 (diff)
downloadop-kernel-dev-280c84d1c1726be7ada045735858acdc8cfdd65a.zip
op-kernel-dev-280c84d1c1726be7ada045735858acdc8cfdd65a.tar.gz
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Martin Schwidefsky: "The bulk of the patches for the 3.13 merge window. Heiko spent quite a bit of work to improve the code generation for the kernel. That includes the exploitation of the interlocked-access facility for the atomics and bitops implementation and the improvement for the -march and -mtune compiler settings. Another important change is the removal of the user_mode=home option, user processes now always run in primary space. The storage keys are not initialized at system startup any more, with that the storage key removal work is complete. For the PCI support the hibernation hooks have been implemented. And as usual cleanup and fixes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (62 commits) s390/scm_blk: fix endless loop for requests != REQ_TYPE_FS s390/mm,tlb: correct tlb flush on page table upgrade s390/mm: page_table_realloc returns failure s390: allow to set gcc -mtune flag s390/percpu: remove this_cpu_xor() implementation s390/vtime: correct idle time calculation s390/time: fix get_tod_clock_ext inline assembly tty/hvc_iucv: remove redundant NULL check s390/dasd: Write to profile data area only if it is available s390: convert use of typedef ctl_table to struct ctl_table s390/pci: cleanup function information block s390/pci: remove CONFIG_PCI_DEBUG dependancy s390/pci: message cleanup Update default configuration s390: add a couple of useful defconfigs s390/percpu: make use of interlocked-access facility 1 instructions s390/percpu: use generic percpu ops for CONFIG_32BIT s390/compat: make psw32_user_bits a constant value again s390: fix handling of runtime instrumentation psw bit s390: fix save and restore of the floating-point-control register ...
Diffstat (limited to 'arch/s390/lib/find.c')
-rw-r--r--arch/s390/lib/find.c77
1 files changed, 77 insertions, 0 deletions
diff --git a/arch/s390/lib/find.c b/arch/s390/lib/find.c
new file mode 100644
index 0000000..620d34d
--- /dev/null
+++ b/arch/s390/lib/find.c
@@ -0,0 +1,77 @@
+/*
+ * MSB0 numbered special bitops handling.
+ *
+ * On s390x the bits are numbered:
+ * |0..............63|64............127|128...........191|192...........255|
+ * and on s390:
+ * |0.....31|31....63|64....95|96...127|128..159|160..191|192..223|224..255|
+ *
+ * The reason for this bit numbering is the fact that the hardware sets bits
+ * in a bitmap starting at bit 0 (MSB) and we don't want to scan the bitmap
+ * from the 'wrong end'.
+ */
+
+#include <linux/compiler.h>
+#include <linux/bitops.h>
+#include <linux/export.h>
+
+unsigned long find_first_bit_inv(const unsigned long *addr, unsigned long size)
+{
+ const unsigned long *p = addr;
+ unsigned long result = 0;
+ unsigned long tmp;
+
+ while (size & ~(BITS_PER_LONG - 1)) {
+ if ((tmp = *(p++)))
+ goto found;
+ result += BITS_PER_LONG;
+ size -= BITS_PER_LONG;
+ }
+ if (!size)
+ return result;
+ tmp = (*p) & (~0UL << (BITS_PER_LONG - size));
+ if (!tmp) /* Are any bits set? */
+ return result + size; /* Nope. */
+found:
+ return result + (__fls(tmp) ^ (BITS_PER_LONG - 1));
+}
+EXPORT_SYMBOL(find_first_bit_inv);
+
+unsigned long find_next_bit_inv(const unsigned long *addr, unsigned long size,
+ unsigned long offset)
+{
+ const unsigned long *p = addr + (offset / BITS_PER_LONG);
+ unsigned long result = offset & ~(BITS_PER_LONG - 1);
+ unsigned long tmp;
+
+ if (offset >= size)
+ return size;
+ size -= result;
+ offset %= BITS_PER_LONG;
+ if (offset) {
+ tmp = *(p++);
+ tmp &= (~0UL >> offset);
+ if (size < BITS_PER_LONG)
+ goto found_first;
+ if (tmp)
+ goto found_middle;
+ size -= BITS_PER_LONG;
+ result += BITS_PER_LONG;
+ }
+ while (size & ~(BITS_PER_LONG-1)) {
+ if ((tmp = *(p++)))
+ goto found_middle;
+ result += BITS_PER_LONG;
+ size -= BITS_PER_LONG;
+ }
+ if (!size)
+ return result;
+ tmp = *p;
+found_first:
+ tmp &= (~0UL << (BITS_PER_LONG - size));
+ if (!tmp) /* Are any bits set? */
+ return result + size; /* Nope. */
+found_middle:
+ return result + (__fls(tmp) ^ (BITS_PER_LONG - 1));
+}
+EXPORT_SYMBOL(find_next_bit_inv);
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