convert ill defined log2() to ilog2()

It's *wrong* to have
			#define log2(n) ffz(~(n))
It should be *reversed*:
			#define log2(n) flz(~(n))
or
			#define log2(n) fls(n)
or just use
			ilog2(n) defined in linux/log2.h.

This patch follows the last solution, recommended by Andrew Morton.

Cc: <linux-ext4@vger.kernel.org>
Cc: Mingming Cao <cmm@us.ibm.com>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Chris Ahna <christopher.j.ahna@intel.com>
Cc: David Mosberger-Tang <davidm@hpl.hp.com>
Cc: Kyle McMartin <kyle@parisc-linux.org>
Cc: Dave Airlie <airlied@linux.ie>
Cc: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 5 deletions

diff --git a/drivers/char/agp/parisc-agp.c b/drivers/char/agp/parisc-agp.c
index f4562cc22343..2939e3570f9d 100644
--- a/drivers/char/agp/parisc-agp.c
+++ b/drivers/char/agp/parisc-agp.c
@@ -18,6 +18,7 @@
 #include <linux/init.h>
 #include <linux/klist.h>
 #include <linux/agp_backend.h>
+#include <linux/log2.h>
 
 #include <asm-parisc/parisc-device.h>
 #include <asm-parisc/ropes.h>
@@ -27,10 +28,6 @@
 #define DRVNAME "quicksilver"
 #define DRVPFX  DRVNAME ": "
 
-#ifndef log2
-#define log2(x)         ffz(~(x))
-#endif
-
 #define AGP8X_MODE_BIT          3
 #define AGP8X_MODE              (1 << AGP8X_MODE_BIT)
 
@@ -92,7 +89,7 @@ parisc_agp_tlbflush(struct agp_memory *mem)
 {
         struct _parisc_agp_info *info = &parisc_agp_info;
 
-        writeq(info->gart_base | log2(info->gart_size), info->ioc_regs+IOC_PCOM);
+        writeq(info->gart_base | ilog2(info->gart_size), info->ioc_regs+IOC_PCOM);
         readq(info->ioc_regs+IOC_PCOM); /* flush */
 }