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, 3 insertions, 6 deletions

diff --git a/drivers/char/agp/hp-agp.c b/drivers/char/agp/hp-agp.c
index 313a133a1172..cbb0444467ba 100644
--- a/drivers/char/agp/hp-agp.c
+++ b/drivers/char/agp/hp-agp.c
@@ -14,15 +14,12 @@
 #include <linux/pci.h>
 #include <linux/init.h>
 #include <linux/agp_backend.h>
+#include <linux/log2.h>
 
 #include <asm/acpi-ext.h>
 
 #include "agp.h"
 
-#ifndef log2
-#define log2(x)         ffz(~(x))
-#endif
-
 #define HP_ZX1_IOC_OFFSET       0x1000  /* ACPI reports SBA, we want IOC */
 
 /* HP ZX1 IOC registers */
@@ -257,7 +254,7 @@ hp_zx1_configure (void)
                 readl(hp->ioc_regs+HP_ZX1_IMASK);
                 writel(hp->iova_base|1, hp->ioc_regs+HP_ZX1_IBASE);
                 readl(hp->ioc_regs+HP_ZX1_IBASE);
-                writel(hp->iova_base|log2(HP_ZX1_IOVA_SIZE), hp->ioc_regs+HP_ZX1_PCOM);
+                writel(hp->iova_base|ilog2(HP_ZX1_IOVA_SIZE), hp->ioc_regs+HP_ZX1_PCOM);
                 readl(hp->ioc_regs+HP_ZX1_PCOM);
         }
 
@@ -285,7 +282,7 @@ hp_zx1_tlbflush (struct agp_memory *mem)
 {
         struct _hp_private *hp = &hp_private;
 
-        writeq(hp->gart_base | log2(hp->gart_size), hp->ioc_regs+HP_ZX1_PCOM);
+        writeq(hp->gart_base | ilog2(hp->gart_size), hp->ioc_regs+HP_ZX1_PCOM);
         readq(hp->ioc_regs+HP_ZX1_PCOM);
 }