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Message-ID: <20070529230135.GA16535@twiddle.net>
Date: Tue, 29 May 2007 16:01:35 -0700
From: Richard Henderson <rth@...ddle.net>
To: Linus Torvalds <torvalds@...ux-foundation.org>,
Andrew Morton <akpm@...ux-foundation.org>
Cc: Ivan Kokshaysky <ink@...assic.park.msu.ru>,
linux-kernel@...r.kernel.org
Subject: [alpha] cleanup in bitops.h
Remove 2 functions private to the alpha implemetation,
in favor of similar functions in <linux/log2.h>.
Provide a more efficient version of the fls64 function
for pre-ev67 alphas.
r~
diff -ruNp /home/rth/work/linux/linux-2.6.22-rc2/arch/alpha/kernel/pci_iommu.c linux-2.6.22-rc2/arch/alpha/kernel/pci_iommu.c
--- /home/rth/work/linux/linux-2.6.22-rc2/arch/alpha/kernel/pci_iommu.c 2007-04-25 20:08:32.000000000 -0700
+++ linux-2.6.22-rc2/arch/alpha/kernel/pci_iommu.c 2007-05-25 15:42:32.000000000 -0700
@@ -7,6 +7,7 @@
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/bootmem.h>
+#include <linux/log2.h>
#include <asm/io.h>
#include <asm/hwrpb.h>
@@ -53,7 +54,7 @@ size_for_memory(unsigned long max)
{
unsigned long mem = max_low_pfn << PAGE_SHIFT;
if (mem < max)
- max = 1UL << ceil_log2(mem);
+ max = roundup_pow_of_two(mem);
return max;
}
.
diff -ruNp /home/rth/work/linux/linux-2.6.22-rc2/arch/alpha/kernel/setup.c linux-2.6.22-rc2/arch/alpha/kernel/setup.c
--- /home/rth/work/linux/linux-2.6.22-rc2/arch/alpha/kernel/setup.c 2007-05-28 15:23:20.000000000 -0700
+++ linux-2.6.22-rc2/arch/alpha/kernel/setup.c 2007-05-25 15:41:20.000000000 -0700
@@ -43,6 +43,7 @@
#include <linux/notifier.h>
#include <asm/setup.h>
#include <asm/io.h>
+#include <linux/log2.h>
extern struct atomic_notifier_head panic_notifier_list;
static int alpha_panic_event(struct notifier_block *, unsigned long, void *);
@@ -1303,7 +1304,7 @@ external_cache_probe(int minsize, int wi
long size = minsize, maxsize = MAX_BCACHE_SIZE * 2;
if (maxsize > (max_low_pfn + 1) << PAGE_SHIFT)
- maxsize = 1 << (floor_log2(max_low_pfn + 1) + PAGE_SHIFT);
+ maxsize = 1 << (ilog2(max_low_pfn + 1) + PAGE_SHIFT);
/* Get the first block cached. */
read_mem_block(__va(0), stride, size);
diff -ruNp /home/rth/work/linux/linux-2.6.22-rc2/arch/alpha/lib/Makefile linux-2.6.22-rc2/arch/alpha/lib/Makefile
--- /home/rth/work/linux/linux-2.6.22-rc2/arch/alpha/lib/Makefile 2007-05-28 15:23:20.000000000 -0700
+++ linux-2.6.22-rc2/arch/alpha/lib/Makefile 2007-05-25 15:43:08.000000000 -0700
@@ -37,7 +37,8 @@ lib-y = __divqu.o __remqu.o __divlu.o __
$(ev6-y)clear_page.o \
$(ev6-y)copy_page.o \
fpreg.o \
- callback_srm.o srm_puts.o srm_printk.o
+ callback_srm.o srm_puts.o srm_printk.o \
+ fls.o
lib-$(CONFIG_SMP) += dec_and_lock.o
diff -ruNp /home/rth/work/linux/linux-2.6.22-rc2/arch/alpha/lib/fls.c linux-2.6.22-rc2/arch/alpha/lib/fls.c
--- /home/rth/work/linux/linux-2.6.22-rc2/arch/alpha/lib/fls.c 1969-12-31 16:00:00.000000000 -0800
+++ linux-2.6.22-rc2/arch/alpha/lib/fls.c 2007-05-28 16:06:46.000000000 -0700
@@ -0,0 +1,38 @@
+/*
+ * arch/alpha/lib/fls.c
+ */
+
+#include <linux/module.h>
+#include <asm/bitops.h>
+
+/* This is fls(x)-1, except zero is held to zero. This allows most
+ efficent input into extbl, plus it allows easy handling of fls(0)=0. */
+
+const unsigned char __flsm1_tab[256] =
+{
+ 0,
+ 0,
+ 1, 1,
+ 2, 2, 2, 2,
+ 3, 3, 3, 3, 3, 3, 3, 3,
+ 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
+
+ 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
+ 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5,
+
+ 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
+ 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
+ 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
+ 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6,
+
+ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+ 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+};
+
+EXPORT_SYMBOL(__flsm1_tab);
diff -ruNp /home/rth/work/linux/linux-2.6.22-rc2/include/asm-alpha/bitops.h linux-2.6.22-rc2/include/asm-alpha/bitops.h
--- /home/rth/work/linux/linux-2.6.22-rc2/include/asm-alpha/bitops.h 2007-04-25 20:08:32.000000000 -0700
+++ linux-2.6.22-rc2/include/asm-alpha/bitops.h 2007-05-28 16:05:18.000000000 -0700
@@ -313,32 +313,29 @@ static inline int ffs(int word)
* fls: find last bit set.
*/
#if defined(CONFIG_ALPHA_EV6) && defined(CONFIG_ALPHA_EV67)
-static inline int fls(int word)
+static inline int fls64(unsigned long word)
{
- return 64 - __kernel_ctlz(word & 0xffffffff);
+ return 64 - __kernel_ctlz(word);
}
#else
-#include <asm-generic/bitops/fls.h>
-#endif
-#include <asm-generic/bitops/fls64.h>
+extern const unsigned char __flsm1_tab[256];
-/* Compute powers of two for the given integer. */
-static inline long floor_log2(unsigned long word)
+static inline int fls64(unsigned long x)
{
-#if defined(CONFIG_ALPHA_EV6) && defined(CONFIG_ALPHA_EV67)
- return 63 - __kernel_ctlz(word);
-#else
- long bit;
- for (bit = -1; word ; bit++)
- word >>= 1;
- return bit;
-#endif
+ unsigned long t, a, r;
+
+ t = __kernel_cmpbge (x, 0x0101010101010101);
+ a = __flsm1_tab[t];
+ t = __kernel_extbl (x, a);
+ r = a*8 + __flsm1_tab[t] + (x != 0);
+
+ return r;
}
+#endif
-static inline long ceil_log2(unsigned long word)
+static inline int fls(int x)
{
- long bit = floor_log2(word);
- return bit + (word > (1UL << bit));
+ return fls64((unsigned int) x);
}
/*
@@ -353,9 +350,20 @@ static inline unsigned long hweight64(un
return __kernel_ctpop(w);
}
-#define hweight32(x) (unsigned int) hweight64((x) & 0xfffffffful)
-#define hweight16(x) (unsigned int) hweight64((x) & 0xfffful)
-#define hweight8(x) (unsigned int) hweight64((x) & 0xfful)
+static inline unsigned int hweight32(unsigned int w)
+{
+ return hweight64(w);
+}
+
+static inline unsigned int hweight16(unsigned int w)
+{
+ return hweight64(w & 0xffff);
+}
+
+static inline unsigned int hweight8(unsigned int w)
+{
+ return hweight64(w & 0xff);
+}
#else
#include <asm-generic/bitops/hweight.h>
#endif
-
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