From: Fengguang Wu <[email protected]>
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: <[email protected]>
Cc: Mingming Cao <[email protected]>
Cc: Bjorn Helgaas <[email protected]>
Cc: Chris Ahna <[email protected]>
Cc: David Mosberger-Tang <[email protected]>
Cc: Kyle McMartin <[email protected]>
Cc: Dave Airlie <[email protected]>
Cc: Dave Jones <[email protected]>
Signed-off-by: Fengguang Wu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
---
drivers/char/agp/hp-agp.c | 9 +++------
drivers/char/agp/i460-agp.c | 5 ++---
drivers/char/agp/parisc-agp.c | 7 ++-----
fs/ext4/super.c | 6 ++----
4 files changed, 9 insertions(+), 18 deletions(-)
diff -puN drivers/char/agp/hp-agp.c~convert-ill-defined-log2-to-ilog2 drivers/char/agp/hp-agp.c
--- a/drivers/char/agp/hp-agp.c~convert-ill-defined-log2-to-ilog2
+++ a/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);
}
diff -puN drivers/char/agp/i460-agp.c~convert-ill-defined-log2-to-ilog2 drivers/char/agp/i460-agp.c
--- a/drivers/char/agp/i460-agp.c~convert-ill-defined-log2-to-ilog2
+++ a/drivers/char/agp/i460-agp.c
@@ -13,6 +13,7 @@
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/agp_backend.h>
+#include <linux/log2.h>
#include "agp.h"
@@ -59,8 +60,6 @@
*/
#define WR_FLUSH_GATT(index) RD_GATT(index)
-#define log2(x) ffz(~(x))
-
static struct {
void *gatt; /* ioremap'd GATT area */
@@ -148,7 +147,7 @@ static int i460_fetch_size (void)
* values[i].size.
*/
values[i].num_entries = (values[i].size << 8) >> (I460_IO_PAGE_SHIFT - 12);
- values[i].page_order = log2((sizeof(u32)*values[i].num_entries) >> PAGE_SHIFT);
+ values[i].page_order = ilog2((sizeof(u32)*values[i].num_entries) >> PAGE_SHIFT);
}
for (i = 0; i < agp_bridge->driver->num_aperture_sizes; i++) {
diff -puN drivers/char/agp/parisc-agp.c~convert-ill-defined-log2-to-ilog2 drivers/char/agp/parisc-agp.c
--- a/drivers/char/agp/parisc-agp.c~convert-ill-defined-log2-to-ilog2
+++ a/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 *m
{
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 */
}
diff -puN fs/ext4/super.c~convert-ill-defined-log2-to-ilog2 fs/ext4/super.c
--- a/fs/ext4/super.c~convert-ill-defined-log2-to-ilog2
+++ a/fs/ext4/super.c
@@ -1415,8 +1415,6 @@ static void ext4_orphan_cleanup (struct
sb->s_flags = s_flags; /* Restore MS_RDONLY status */
}
-#define log2(n) ffz(~(n))
-
/*
* Maximal file size. There is a direct, and {,double-,triple-}indirect
* block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
@@ -1689,8 +1687,8 @@ static int ext4_fill_super (struct super
sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
sbi->s_sbh = bh;
sbi->s_mount_state = le16_to_cpu(es->s_state);
- sbi->s_addr_per_block_bits = log2(EXT4_ADDR_PER_BLOCK(sb));
- sbi->s_desc_per_block_bits = log2(EXT4_DESC_PER_BLOCK(sb));
+ sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
+ sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
for (i=0; i < 4; i++)
sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
sbi->s_def_hash_version = es->s_def_hash_version;
_