The patch titled
LOG2: Alter roundup_pow_of_two() so that it can use a ilog2() on a constant
has been added to the -mm tree. Its filename is
log2-alter-roundup_pow_of_two-so-that-it-can-use-a-ilog2-on-a-constant.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: LOG2: Alter roundup_pow_of_two() so that it can use a ilog2() on a constant
From: David Howells <dhowells@xxxxxxxxxx>
Alter roundup_pow_of_two() so that it can make use of ilog2() on a constant to
produce a constant value, retaining the ability for an arch to override it in
the non-const case.
This permits the function to be used to initialise variables.
Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
include/linux/kernel.h | 6 ------
include/linux/log2.h | 26 ++++++++++++++++++++++++++
2 files changed, 26 insertions(+), 6 deletions(-)
diff -puN include/linux/kernel.h~log2-alter-roundup_pow_of_two-so-that-it-can-use-a-ilog2-on-a-constant include/linux/kernel.h
--- a/include/linux/kernel.h~log2-alter-roundup_pow_of_two-so-that-it-can-use-a-ilog2-on-a-constant
+++ a/include/linux/kernel.h
@@ -156,12 +156,6 @@ static inline int printk(const char *s,
unsigned long int_sqrt(unsigned long);
-static inline unsigned long
-__attribute_const__ roundup_pow_of_two(unsigned long x)
-{
- return 1UL << fls_long(x - 1);
-}
-
extern int printk_ratelimit(void);
extern int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst);
diff -puN include/linux/log2.h~log2-alter-roundup_pow_of_two-so-that-it-can-use-a-ilog2-on-a-constant include/linux/log2.h
--- a/include/linux/log2.h~log2-alter-roundup_pow_of_two-so-that-it-can-use-a-ilog2-on-a-constant
+++ a/include/linux/log2.h
@@ -43,6 +43,15 @@ int __ilog2_u64(u64 n)
}
#endif
+/*
+ * round up to nearest power of two
+ */
+static inline __attribute__((const))
+unsigned long __roundup_pow_of_two(unsigned long n)
+{
+ return 1UL << fls_long(n - 1);
+}
+
/**
* ilog2 - log of base 2 of 32-bit or a 64-bit unsigned value
* @n - parameter
@@ -128,4 +137,21 @@ int __ilog2_u64(u64 n)
__ilog2_u64(n) \
)
+/**
+ * roundup_pow_of_two - round the given value up to nearest power of two
+ * @n - parameter
+ *
+ * round the given balue up to the nearest power of two
+ * - the result is undefined when n == 0
+ * - this can be used to initialise global variables from constant data
+ */
+#define roundup_pow_of_two(n) \
+( \
+ __builtin_constant_p(n) ? ( \
+ (n == 1) ? 0 : \
+ (1UL << (ilog2((n) - 1) + 1)) \
+ ) : \
+ __roundup_pow_of_two(n) \
+ )
+
#endif /* _LINUX_LOG2_H */
_
Patches currently in -mm which might be from dhowells@xxxxxxxxxx are
origin.patch
i386-irqs-build-fix.patch
irq_reqs-export-__irq_regs.patch
um-irq-changes-break-build.patch
x86_64-irq_regs-fix.patch
nfs-represent-64-bit-fileids-as-64-bit-inode-numbers-on-32-bit-systems.patch
reiserfs-make-sure-all-dentries-refs-are-released-before-calling-kill_block_super-try-2.patch
fs-cache-provide-a-filesystem-specific-syncable-page-bit.patch
fs-cache-generic-filesystem-caching-facility.patch
fs-cache-release-page-private-in-failed-readahead.patch
fs-cache-release-page-private-after-failed-readahead-12.patch
fs-cache-make-kafs-use-fs-cache.patch
fs-cache-make-kafs-use-fs-cache-fix.patch
fs-cache-make-kafs-use-fs-cache-12.patch
fs-cache-make-kafs-use-fs-cache-12-fix.patch
fs-cache-make-kafs-use-fs-cache-kconfig-fix.patch
fs-cache-make-kafs-use-fs-cache-vs-streamline-generic_file_-interfaces-and-filemap.patch
nfs-use-local-caching.patch
nfs-use-local-caching-12.patch
nfs-use-local-caching-12-fix.patch
nfs-use-local-caching-kconfig-fix.patch
nfs-use-local-caching-configh.patch
add-missing-page_copy-export-for-ppc-and-powerpc.patch
fs-cache-cachefiles-ia64-missing-copy_page-export.patch
fs-cache-cachefiles-a-cache-that-backs-onto-a-mounted-filesystem.patch
fs-cache-cachefiles-a-cache-that-backs-onto-a-mounted-filesystem-fscache-fix-gfp_t-sparse-annotations.patch
fs-cache-cachefiles-a-cache-that-backs-onto-a-mounted-filesystem-cachefiles-printk-format-warning.patch
fs-cache-cachefiles-a-cache-that-backs-onto-a-mounted-filesystem-warning-fixes.patch
fs-cache-cachefiles-a-cache-that-backs-onto-a-mounted-filesystem-cachefiles-cachefiles_write_page-shouldnt-indicate-error-twice.patch
fscache-kconfig-tidying.patch
fs-cache-cachefiles-a-cache-that-backs-onto-a-mounted-filesystem-cachefiles-handle-enospc-on-create-mkdir-better.patch
fs-cache-cachefiles-a-cache-that-backs-onto-a-mounted-filesystem-inode-count-maintenance.patch
autofs-make-sure-all-dentries-refs-are-released-before-calling-kill_anon_super.patch
vfs-destroy-the-dentries-contributed-by-a-superblock-on-unmounting.patch
afs-amend-the-afs-configuration-options.patch
reiser4-get_sb_dev-fix.patch
log2-implement-a-general-integer-log2-facility-in-the-kernel.patch
log2-alter-roundup_pow_of_two-so-that-it-can-use-a-ilog2-on-a-constant.patch
log2-alter-get_order-so-that-it-can-make-use-of-ilog2-on-a-constant.patch
log2-provide-ilog2-fallbacks-for-powerpc.patch
mutex-subsystem-synchro-test-module.patch
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