aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorDavid Howells <dhowells@redhat.com>2006-12-08 02:37:49 -0800
committerLinus Torvalds <torvalds@woody.osdl.org>2006-12-08 08:28:51 -0800
commitf0d1b0b30d250a07627ad8b9fbbb5c7cc08422e8 (patch)
tree0aa5379150574374351fb92af7881a48dbfcf2ce
parentb3d7ae5f47a58a9f7b152deeaf7daa1fc558a8f1 (diff)
downloadlinux-linaro-f0d1b0b30d250a07627ad8b9fbbb5c7cc08422e8.tar.gz
[PATCH] LOG2: Implement a general integer log2 facility in the kernel
This facility provides three entry points: ilog2() Log base 2 of unsigned long ilog2_u32() Log base 2 of u32 ilog2_u64() Log base 2 of u64 These facilities can either be used inside functions on dynamic data: int do_something(long q) { ...; y = ilog2(x) ...; } Or can be used to statically initialise global variables with constant values: unsigned n = ilog2(27); When performing static initialisation, the compiler will report "error: initializer element is not constant" if asked to take a log of zero or of something not reducible to a constant. They treat negative numbers as unsigned. When not dealing with a constant, they fall back to using fls() which permits them to use arch-specific log calculation instructions - such as BSR on x86/x86_64 or SCAN on FRV - if available. [akpm@osdl.org: MMC fix] Signed-off-by: David Howells <dhowells@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: David Howells <dhowells@redhat.com> Cc: Wojtek Kaniewski <wojtekka@toxygen.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--arch/alpha/Kconfig8
-rw-r--r--arch/arm/Kconfig8
-rw-r--r--arch/arm26/Kconfig8
-rw-r--r--arch/avr32/Kconfig8
-rw-r--r--arch/cris/Kconfig8
-rw-r--r--arch/frv/Kconfig8
-rw-r--r--arch/h8300/Kconfig8
-rw-r--r--arch/i386/Kconfig.cpu8
-rw-r--r--arch/ia64/Kconfig8
-rw-r--r--arch/m32r/Kconfig8
-rw-r--r--arch/m68k/Kconfig8
-rw-r--r--arch/m68knommu/Kconfig8
-rw-r--r--arch/mips/Kconfig8
-rw-r--r--arch/parisc/Kconfig8
-rw-r--r--arch/powerpc/Kconfig8
-rw-r--r--arch/ppc/Kconfig8
-rw-r--r--arch/s390/Kconfig8
-rw-r--r--arch/sh/Kconfig8
-rw-r--r--arch/sh64/Kconfig8
-rw-r--r--arch/sparc/Kconfig8
-rw-r--r--arch/sparc64/Kconfig8
-rw-r--r--arch/v850/Kconfig8
-rw-r--r--arch/x86_64/Kconfig8
-rw-r--r--arch/xtensa/Kconfig8
-rw-r--r--drivers/infiniband/hw/mthca/mthca_provider.c4
-rw-r--r--drivers/infiniband/hw/mthca/mthca_qp.c4
-rw-r--r--drivers/infiniband/hw/mthca/mthca_srq.c4
-rw-r--r--drivers/infiniband/ulp/iser/iser_memory.c4
-rw-r--r--drivers/md/dm-crypt.c2
-rw-r--r--drivers/mmc/tifm_sd.c2
-rw-r--r--fs/ext2/super.c6
-rw-r--r--fs/ext3/super.c6
-rw-r--r--include/asm-frv/bitops.h44
-rw-r--r--include/linux/kernel.h9
-rw-r--r--include/linux/log2.h131
-rw-r--r--mm/page_alloc.c4
36 files changed, 384 insertions, 28 deletions
diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index 7e55ea66c6d..84caf50725b 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -25,6 +25,14 @@ config RWSEM_XCHGADD_ALGORITHM
bool
default y
+config ARCH_HAS_ILOG2_U32
+ bool
+ default n
+
+config ARCH_HAS_ILOG2_U64
+ bool
+ default n
+
config GENERIC_FIND_NEXT_BIT
bool
default y
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 8c05d4321ae..aa1d400d721 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -74,6 +74,14 @@ config RWSEM_GENERIC_SPINLOCK
config RWSEM_XCHGADD_ALGORITHM
bool
+config ARCH_HAS_ILOG2_U32
+ bool
+ default n
+
+config ARCH_HAS_ILOG2_U64
+ bool
+ default n
+
config GENERIC_HWEIGHT
bool
default y
diff --git a/arch/arm26/Kconfig b/arch/arm26/Kconfig
index c14fe918bc4..74eba8b5a8c 100644
--- a/arch/arm26/Kconfig
+++ b/arch/arm26/Kconfig
@@ -41,6 +41,14 @@ config RWSEM_GENERIC_SPINLOCK
config RWSEM_XCHGADD_ALGORITHM
bool
+config ARCH_HAS_ILOG2_U32
+ bool
+ default n
+
+config ARCH_HAS_ILOG2_U64
+ bool
+ default n
+
config GENERIC_HWEIGHT
bool
default y
diff --git a/arch/avr32/Kconfig b/arch/avr32/Kconfig
index 5f1694eea84..bb059a4e1df 100644
--- a/arch/avr32/Kconfig
+++ b/arch/avr32/Kconfig
@@ -45,6 +45,14 @@ config GENERIC_TIME
config RWSEM_XCHGADD_ALGORITHM
bool
+config ARCH_HAS_ILOG2_U32
+ bool
+ default n
+
+config ARCH_HAS_ILOG2_U64
+ bool
+ default n
+
config GENERIC_BUST_SPINLOCK
bool
diff --git a/arch/cris/Kconfig b/arch/cris/Kconfig
index 6a1238a29d6..3474309e049 100644
--- a/arch/cris/Kconfig
+++ b/arch/cris/Kconfig
@@ -16,6 +16,14 @@ config RWSEM_GENERIC_SPINLOCK
config RWSEM_XCHGADD_ALGORITHM
bool
+config ARCH_HAS_ILOG2_U32
+ bool
+ default n
+
+config ARCH_HAS_ILOG2_U64
+ bool
+ default n
+
config GENERIC_FIND_NEXT_BIT
bool
default y
diff --git a/arch/frv/Kconfig b/arch/frv/Kconfig
index cf1c446e003..7561d7b72e7 100644
--- a/arch/frv/Kconfig
+++ b/arch/frv/Kconfig
@@ -41,6 +41,14 @@ config TIME_LOW_RES
bool
default y
+config ARCH_HAS_ILOG2_U32
+ bool
+ default y
+
+config ARCH_HAS_ILOG2_U64
+ bool
+ default y
+
mainmenu "Fujitsu FR-V Kernel Configuration"
source "init/Kconfig"
diff --git a/arch/h8300/Kconfig b/arch/h8300/Kconfig
index cabf0bfffc5..34a84bc4baf 100644
--- a/arch/h8300/Kconfig
+++ b/arch/h8300/Kconfig
@@ -29,6 +29,14 @@ config RWSEM_XCHGADD_ALGORITHM
bool
default n
+config ARCH_HAS_ILOG2_U32
+ bool
+ default n
+
+config ARCH_HAS_ILOG2_U64
+ bool
+ default n
+
config GENERIC_FIND_NEXT_BIT
bool
default y
diff --git a/arch/i386/Kconfig.cpu b/arch/i386/Kconfig.cpu
index 821fd269ca5..2aecfba4ac4 100644
--- a/arch/i386/Kconfig.cpu
+++ b/arch/i386/Kconfig.cpu
@@ -248,6 +248,14 @@ config RWSEM_XCHGADD_ALGORITHM
depends on !M386
default y
+config ARCH_HAS_ILOG2_U32
+ bool
+ default n
+
+config ARCH_HAS_ILOG2_U64
+ bool
+ default n
+
config GENERIC_CALIBRATE_DELAY
bool
default y
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 75d839715b2..fcacfe291b9 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -34,6 +34,14 @@ config RWSEM_XCHGADD_ALGORITHM
bool
default y
+config ARCH_HAS_ILOG2_U32
+ bool
+ default n
+
+config ARCH_HAS_ILOG2_U64
+ bool
+ default n
+
config GENERIC_FIND_NEXT_BIT
bool
default y
diff --git a/arch/m32r/Kconfig b/arch/m32r/Kconfig
index 41fd490af3b..f383dab973f 100644
--- a/arch/m32r/Kconfig
+++ b/arch/m32r/Kconfig
@@ -214,6 +214,14 @@ config RWSEM_XCHGADD_ALGORITHM
bool
default n
+config ARCH_HAS_ILOG2_U32
+ bool
+ default n
+
+config ARCH_HAS_ILOG2_U64
+ bool
+ default n
+
config GENERIC_FIND_NEXT_BIT
bool
default y
diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index 7bc14461a6a..70a577c89c7 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -17,6 +17,14 @@ config RWSEM_GENERIC_SPINLOCK
config RWSEM_XCHGADD_ALGORITHM
bool
+config ARCH_HAS_ILOG2_U32
+ bool
+ default n
+
+config ARCH_HAS_ILOG2_U64
+ bool
+ default n
+
config GENERIC_HWEIGHT
bool
default y
diff --git a/arch/m68knommu/Kconfig b/arch/m68knommu/Kconfig
index aa70dde5422..25993c2a8fb 100644
--- a/arch/m68knommu/Kconfig
+++ b/arch/m68knommu/Kconfig
@@ -25,6 +25,14 @@ config RWSEM_XCHGADD_ALGORITHM
bool
default n
+config ARCH_HAS_ILOG2_U32
+ bool
+ default n
+
+config ARCH_HAS_ILOG2_U64
+ bool
+ default n
+
config GENERIC_FIND_NEXT_BIT
bool
default y
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index d8af858fe3f..57af8d8cf46 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -819,6 +819,14 @@ config RWSEM_GENERIC_SPINLOCK
config RWSEM_XCHGADD_ALGORITHM
bool
+config ARCH_HAS_ILOG2_U32
+ bool
+ default n
+
+config ARCH_HAS_ILOG2_U64
+ bool
+ default n
+
config GENERIC_FIND_NEXT_BIT
bool
default y
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index d2101237442..0f9ff618c6d 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -25,6 +25,14 @@ config RWSEM_GENERIC_SPINLOCK
config RWSEM_XCHGADD_ALGORITHM
bool
+config ARCH_HAS_ILOG2_U32
+ bool
+ default n
+
+config ARCH_HAS_ILOG2_U64
+ bool
+ default n
+
config GENERIC_FIND_NEXT_BIT
bool
default y
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 291c95ac4b3..97c7a212cdd 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -41,6 +41,14 @@ config RWSEM_XCHGADD_ALGORITHM
bool
default y
+config ARCH_HAS_ILOG2_U32
+ bool
+ default n
+
+config ARCH_HAS_ILOG2_U64
+ bool
+ default n
+
config GENERIC_HWEIGHT
bool
default y
diff --git a/arch/ppc/Kconfig b/arch/ppc/Kconfig
index f76a146cff1..692b5ba5320 100644
--- a/arch/ppc/Kconfig
+++ b/arch/ppc/Kconfig
@@ -19,6 +19,14 @@ config RWSEM_XCHGADD_ALGORITHM
bool
default y
+config ARCH_HAS_ILOG2_U32
+ bool
+ default y
+
+config ARCH_HAS_ILOG2_U64
+ bool
+ default n
+
config GENERIC_HWEIGHT
bool
default y
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 583d9ff0a57..45e47bfb68a 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -22,6 +22,14 @@ config RWSEM_XCHGADD_ALGORITHM
bool
default y
+config ARCH_HAS_ILOG2_U32
+ bool
+ default n
+
+config ARCH_HAS_ILOG2_U64
+ bool
+ default n
+
config GENERIC_HWEIGHT
bool
default y
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index d83d64af31f..8e24c40662e 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -59,6 +59,14 @@ config LOCKDEP_SUPPORT
bool
default y
+config ARCH_HAS_ILOG2_U32
+ bool
+ default n
+
+config ARCH_HAS_ILOG2_U64
+ bool
+ default n
+
source "init/Kconfig"
menu "System type"
diff --git a/arch/sh64/Kconfig b/arch/sh64/Kconfig
index 58c678e0666..7bc0744b7ab 100644
--- a/arch/sh64/Kconfig
+++ b/arch/sh64/Kconfig
@@ -39,6 +39,14 @@ config RWSEM_XCHGADD_ALGORITHM
config GENERIC_ISA_DMA
bool
+config ARCH_HAS_ILOG2_U32
+ bool
+ default n
+
+config ARCH_HAS_ILOG2_U64
+ bool
+ default n
+
source init/Kconfig
menu "System type"
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 92a7c8a636d..d0dec1ea2ee 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -166,6 +166,14 @@ config ARCH_MAY_HAVE_PC_FDC
bool
default y
+config ARCH_HAS_ILOG2_U32
+ bool
+ default n
+
+config ARCH_HAS_ILOG2_U64
+ bool
+ default n
+
config SUN_PM
bool
default y
diff --git a/arch/sparc64/Kconfig b/arch/sparc64/Kconfig
index b627f8dbcaa..d391d11f245 100644
--- a/arch/sparc64/Kconfig
+++ b/arch/sparc64/Kconfig
@@ -34,6 +34,14 @@ config ARCH_MAY_HAVE_PC_FDC
bool
default y
+config ARCH_HAS_ILOG2_U32
+ bool
+ default n
+
+config ARCH_HAS_ILOG2_U64
+ bool
+ default n
+
config AUDIT_ARCH
bool
default y
diff --git a/arch/v850/Kconfig b/arch/v850/Kconfig
index 37ec644603a..bcf825875d1 100644
--- a/arch/v850/Kconfig
+++ b/arch/v850/Kconfig
@@ -38,6 +38,14 @@ config TIME_LOW_RES
bool
default y
+config ARCH_HAS_ILOG2_U32
+ bool
+ default n
+
+config ARCH_HAS_ILOG2_U64
+ bool
+ default n
+
# Turn off some random 386 crap that can affect device config
config ISA
bool
diff --git a/arch/x86_64/Kconfig b/arch/x86_64/Kconfig
index 3254a616c69..3ac581d1720 100644
--- a/arch/x86_64/Kconfig
+++ b/arch/x86_64/Kconfig
@@ -101,6 +101,14 @@ config GENERIC_BUG
default y
depends on BUG
+config ARCH_HAS_ILOG2_U32
+ bool
+ default n
+
+config ARCH_HAS_ILOG2_U64
+ bool
+ default n
+
source "init/Kconfig"
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index c1e69a1f92a..9eccfbd1b53 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -34,6 +34,14 @@ config GENERIC_HARDIRQS
bool
default y
+config ARCH_HAS_ILOG2_U32
+ bool
+ default n
+
+config ARCH_HAS_ILOG2_U64
+ bool
+ default n
+
source "init/Kconfig"
menu "Processor type and features"
diff --git a/drivers/infiniband/hw/mthca/mthca_provider.c b/drivers/infiniband/hw/mthca/mthca_provider.c
index 21422a3336a..7ec7c4b937f 100644
--- a/drivers/infiniband/hw/mthca/mthca_provider.c
+++ b/drivers/infiniband/hw/mthca/mthca_provider.c
@@ -124,7 +124,7 @@ static int mthca_query_device(struct ib_device *ibdev,
props->max_map_per_fmr = 255;
else
props->max_map_per_fmr =
- (1 << (32 - long_log2(mdev->limits.num_mpts))) - 1;
+ (1 << (32 - ilog2(mdev->limits.num_mpts))) - 1;
err = 0;
out:
@@ -816,7 +816,7 @@ static int mthca_resize_cq(struct ib_cq *ibcq, int entries, struct ib_udata *uda
lkey = ucmd.lkey;
}
- ret = mthca_RESIZE_CQ(dev, cq->cqn, lkey, long_log2(entries), &status);
+ ret = mthca_RESIZE_CQ(dev, cq->cqn, lkey, ilog2(entries), &status);
if (status)
ret = -EINVAL;
diff --git a/drivers/infiniband/hw/mthca/mthca_qp.c b/drivers/infiniband/hw/mthca/mthca_qp.c
index 33e3ba7937f..d844a2569b4 100644
--- a/drivers/infiniband/hw/mthca/mthca_qp.c
+++ b/drivers/infiniband/hw/mthca/mthca_qp.c
@@ -636,11 +636,11 @@ int mthca_modify_qp(struct ib_qp *ibqp, struct ib_qp_attr *attr, int attr_mask,
if (mthca_is_memfree(dev)) {
if (qp->rq.max)
- qp_context->rq_size_stride = long_log2(qp->rq.max) << 3;
+ qp_context->rq_size_stride = ilog2(qp->rq.max) << 3;
qp_context->rq_size_stride |= qp->rq.wqe_shift - 4;
if (qp->sq.max)
- qp_context->sq_size_stride = long_log2(qp->sq.max) << 3;
+ qp_context->sq_size_stride = ilog2(qp->sq.max) << 3;
qp_context->sq_size_stride |= qp->sq.wqe_shift - 4;
}
diff --git a/drivers/infiniband/hw/mthca/mthca_srq.c b/drivers/infiniband/hw/mthca/mthca_srq.c
index 34d2c476896..10684da33d5 100644
--- a/drivers/infiniband/hw/mthca/mthca_srq.c
+++ b/drivers/infiniband/hw/mthca/mthca_srq.c
@@ -120,7 +120,7 @@ static void mthca_arbel_init_srq_context(struct mthca_dev *dev,
memset(context, 0, sizeof *context);
- logsize = long_log2(srq->max);
+ logsize = ilog2(srq->max);
context->state_logsize_srqn = cpu_to_be32(logsize << 24 | srq->srqn);
context->lkey = cpu_to_be32(srq->mr.ibmr.lkey);
context->db_index = cpu_to_be32(srq->db_index);
@@ -213,7 +213,7 @@ int mthca_alloc_srq(struct mthca_dev *dev, struct mthca_pd *pd,
if (!mthca_is_memfree(dev) && (ds > dev->limits.max_desc_sz))
return -EINVAL;
- srq->wqe_shift = long_log2(ds);
+ srq->wqe_shift = ilog2(ds);
srq->srqn = mthca_alloc(&dev->srq_table.alloc);
if (srq->srqn == -1)
diff --git a/drivers/infiniband/ulp/iser/iser_memory.c b/drivers/infiniband/ulp/iser/iser_memory.c
index 5e122501fd8..3aedd59b8a8 100644
--- a/drivers/infiniband/ulp/iser/iser_memory.c
+++ b/drivers/infiniband/ulp/iser/iser_memory.c
@@ -114,7 +114,7 @@ int iser_start_rdma_unaligned_sg(struct iscsi_iser_cmd_task *iser_ctask,
if (cmd_data_len > ISER_KMALLOC_THRESHOLD)
mem = (void *)__get_free_pages(GFP_NOIO,
- long_log2(roundup_pow_of_two(cmd_data_len)) - PAGE_SHIFT);
+ ilog2(roundup_pow_of_two(cmd_data_len)) - PAGE_SHIFT);
else
mem = kmalloc(cmd_data_len, GFP_NOIO);
@@ -211,7 +211,7 @@ void iser_finalize_rdma_unaligned_sg(struct iscsi_iser_cmd_task *iser_ctask,
if (cmd_data_len > ISER_KMALLOC_THRESHOLD)
free_pages((unsigned long)mem_copy->copy_buf,
- long_log2(roundup_pow_of_two(cmd_data_len)) - PAGE_SHIFT);
+ ilog2(roundup_pow_of_two(cmd_data_len)) - PAGE_SHIFT);
else
kfree(mem_copy->copy_buf);
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index a1086ee8ccc..96152868525 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -220,7 +220,7 @@ static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
const char *opts)
{
unsigned int bs = crypto_blkcipher_blocksize(cc->tfm);
- int log = long_log2(bs);
+ int log = ilog2(bs);
/* we need to calculate how far we must shift the sector count
* to get the cipher block count, we use this shift in _gen */
diff --git a/drivers/mmc/tifm_sd.c b/drivers/mmc/tifm_sd.c
index e846499a004..f18ad998b3c 100644
--- a/drivers/mmc/tifm_sd.c
+++ b/drivers/mmc/tifm_sd.c
@@ -387,7 +387,7 @@ static void tifm_sd_prepare_data(struct tifm_sd *card, struct mmc_command *cmd)
writel(TIFM_FIFO_INT_SETALL,
sock->addr + SOCK_DMA_FIFO_INT_ENABLE_CLEAR);
- writel(long_log2(cmd->data->blksz) - 2,
+ writel(ilog2(cmd->data->blksz) - 2,
sock->addr + SOCK_FIFO_PAGE_SIZE);
writel(TIFM_FIFO_ENABLE, sock->addr + SOCK_FIFO_CONTROL);
writel(TIFM_FIFO_INTMASK, sock->addr + SOCK_DMA_FIFO_INT_ENABLE_SET);
diff --git a/fs/ext2/super.c b/fs/ext2/super.c
index 255cef5f742..6347c2dbdd8 100644
--- a/fs/ext2/super.c
+++ b/fs/ext2/super.c
@@ -597,8 +597,6 @@ static int ext2_check_descriptors (struct super_block * sb)
return 1;
}
-#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.
@@ -834,9 +832,9 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent)
sbi->s_sbh = bh;
sbi->s_mount_state = le16_to_cpu(es->s_state);
sbi->s_addr_per_block_bits =
- log2 (EXT2_ADDR_PER_BLOCK(sb));
+ ilog2 (EXT2_ADDR_PER_BLOCK(sb));
sbi->s_desc_per_block_bits =
- log2 (EXT2_DESC_PER_BLOCK(sb));
+ ilog2 (EXT2_DESC_PER_BLOCK(sb));
if (sb->s_magic != EXT2_SUPER_MAGIC)
goto cantfind_ext2;
diff --git a/fs/ext3/super.c b/fs/ext3/super.c
index 580b8a6ca97..b34886734a4 100644
--- a/fs/ext3/super.c
+++ b/fs/ext3/super.c
@@ -1347,8 +1347,6 @@ static void ext3_orphan_cleanup (struct super_block * sb,
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.
@@ -1597,8 +1595,8 @@ static int ext3_fill_super (struct super_block *sb, void *data, int silent)
sbi->s_desc_per_block = blocksize / sizeof(struct ext3_group_desc);
sbi->s_sbh = bh;
sbi->s_mount_state = le16_to_cpu(es->s_state);
- sbi->s_addr_per_block_bits = log2(EXT3_ADDR_PER_BLOCK(sb));
- sbi->s_desc_per_block_bits = log2(EXT3_DESC_PER_BLOCK(sb));
+ sbi->s_addr_per_block_bits = ilog2(EXT3_ADDR_PER_BLOCK(sb));
+ sbi->s_desc_per_block_bits = ilog2(EXT3_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;
diff --git a/include/asm-frv/bitops.h b/include/asm-frv/bitops.h
index 1f70d47148b..f8560edf59f 100644
--- a/include/asm-frv/bitops.h
+++ b/include/asm-frv/bitops.h
@@ -256,6 +256,50 @@ int __ffs(unsigned long x)
return 31 - bit;
}
+/*
+ * special slimline version of fls() for calculating ilog2_u32()
+ * - note: no protection against n == 0
+ */
+#define ARCH_HAS_ILOG2_U32
+static inline __attribute__((const))
+int __ilog2_u32(u32 n)
+{
+ int bit;
+ asm("scan %1,gr0,%0" : "=r"(bit) : "r"(n));
+ return 31 - bit;
+}
+
+/*
+ * special slimline version of fls64() for calculating ilog2_u64()
+ * - note: no protection against n == 0
+ */
+#define ARCH_HAS_ILOG2_U64
+static inline __attribute__((const))
+int __ilog2_u64(u64 n)
+{
+ union {
+ u64 ll;
+ struct { u32 h, l; };
+ } _;
+ int bit, x, y;
+
+ _.ll = n;
+
+ asm(" subcc %3,gr0,gr0,icc0 \n"
+ " ckeq icc0,cc4 \n"
+ " cscan.p %3,gr0,%0 ,cc4,0 \n"
+ " setlos #63,%1 \n"
+ " cscan.p %4,gr0,%0 ,cc4,1 \n"
+ " setlos #31,%2 \n"
+ " csub.p %1,%0,%0 ,cc4,0 \n"
+ " csub %2,%0,%0 ,cc4,1 \n"
+ : "=&r"(bit), "=r"(x), "=r"(y)
+ : "0r"(_.h), "r"(_.l)
+ : "icc0", "cc4"
+ );
+ return bit;
+}
+
#include <asm-generic/bitops/sched.h>
#include <asm-generic/bitops/hweight.h>
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 6738283ac38..3710cce1664 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -13,6 +13,7 @@
#include <linux/types.h>
#include <linux/compiler.h>
#include <linux/bitops.h>
+#include <linux/log2.h>
#include <asm/byteorder.h>
#include <asm/bug.h>
@@ -157,14 +158,6 @@ static inline int printk(const char *s, ...) { return 0; }
unsigned long int_sqrt(unsigned long);
-static inline int __attribute_pure__ long_log2(unsigned long x)
-{
- int r = 0;
- for (x >>= 1; x > 0; x >>= 1)
- r++;
- return r;
-}
-
static inline unsigned long
__attribute_const__ roundup_pow_of_two(unsigned long x)
{
diff --git a/include/linux/log2.h b/include/linux/log2.h
new file mode 100644
index 00000000000..3979c60325f
--- /dev/null
+++ b/include/linux/log2.h
@@ -0,0 +1,131 @@
+/* Integer base 2 logarithm calculation
+ *
+ * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#ifndef _LINUX_LOG2_H
+#define _LINUX_LOG2_H
+
+#include <linux/types.h>
+#include <linux/bitops.h>
+
+/*
+ * deal with unrepresentable constant logarithms
+ */
+extern __attribute__((const, noreturn))
+int ____ilog2_NaN(void);
+
+/*
+ * non-constant log of base 2 calculators
+ * - the arch may override these in asm/bitops.h if they can be implemented
+ * more efficiently than using fls() and fls64()
+ * - the arch is not required to handle n==0 if implementing the fallback
+ */
+#ifndef CONFIG_ARCH_HAS_ILOG2_U32
+static inline __attribute__((const))
+int __ilog2_u32(u32 n)
+{
+ return fls(n) - 1;
+}
+#endif
+
+#ifndef CONFIG_ARCH_HAS_ILOG2_U64
+static inline __attribute__((const))
+int __ilog2_u64(u64 n)
+{
+ return fls64(n) - 1;
+}
+#endif
+
+/**
+ * ilog2 - log of base 2 of 32-bit or a 64-bit unsigned value
+ * @n - parameter
+ *
+ * constant-capable log of base 2 calculation
+ * - this can be used to initialise global variables from constant data, hence
+ * the massive ternary operator construction
+ *
+ * selects the appropriately-sized optimised version depending on sizeof(n)
+ */
+#define ilog2(n) \
+( \
+ __builtin_constant_p(n) ? ( \
+ (n) < 1 ? ____ilog2_NaN() : \
+ (n) & (1ULL << 63) ? 63 : \
+ (n) & (1ULL << 62) ? 62 : \
+ (n) & (1ULL << 61) ? 61 : \
+ (n) & (1ULL << 60) ? 60 : \
+ (n) & (1ULL << 59) ? 59 : \
+ (n) & (1ULL << 58) ? 58 : \
+ (n) & (1ULL << 57) ? 57 : \
+ (n) & (1ULL << 56) ? 56 : \
+ (n) & (1ULL << 55) ? 55 : \
+ (n) & (1ULL << 54) ? 54 : \
+ (n) & (1ULL << 53) ? 53 : \
+ (n) & (1ULL << 52) ? 52 : \
+ (n) & (1ULL << 51) ? 51 : \
+ (n) & (1ULL << 50) ? 50 : \
+ (n) & (1ULL << 49) ? 49 : \
+ (n) & (1ULL << 48) ? 48 : \
+ (n) & (1ULL << 47) ? 47 : \
+ (n) & (1ULL << 46) ? 46 : \
+ (n) & (1ULL << 45) ? 45 : \
+ (n) & (1ULL << 44) ? 44 : \
+ (n) & (1ULL << 43) ? 43 : \
+ (n) & (1ULL << 42) ? 42 : \
+ (n) & (1ULL << 41) ? 41 : \
+ (n) & (1ULL << 40) ? 40 : \
+ (n) & (1ULL << 39) ? 39 : \
+ (n) & (1ULL << 38) ? 38 : \
+ (n) & (1ULL << 37) ? 37 : \
+ (n) & (1ULL << 36) ? 36 : \
+ (n) & (1ULL << 35) ? 35 : \
+ (n) & (1ULL << 34) ? 34 : \
+ (n) & (1ULL << 33) ? 33 : \
+ (n) & (1ULL << 32) ? 32 : \
+ (n) & (1ULL << 31) ? 31 : \
+ (n) & (1ULL << 30) ? 30 : \
+ (n) & (1ULL << 29) ? 29 : \
+ (n) & (1ULL << 28) ? 28 : \
+ (n) & (1ULL << 27) ? 27 : \
+ (n) & (1ULL << 26) ? 26 : \
+ (n) & (1ULL << 25) ? 25 : \
+ (n) & (1ULL << 24) ? 24 : \
+ (n) & (1ULL << 23) ? 23 : \
+ (n) & (1ULL << 22) ? 22 : \
+ (n) & (1ULL << 21) ? 21 : \
+ (n) & (1ULL << 20) ? 20 : \
+ (n) & (1ULL << 19) ? 19 : \
+ (n) & (1ULL << 18) ? 18 : \
+ (n) & (1ULL << 17) ? 17 : \
+ (n) & (1ULL << 16) ? 16 : \
+ (n) & (1ULL << 15) ? 15 : \
+ (n) & (1ULL << 14) ? 14 : \
+ (n) & (1ULL << 13) ? 13 : \
+ (n) & (1ULL << 12) ? 12 : \
+ (n) & (1ULL << 11) ? 11 : \
+ (n) & (1ULL << 10) ? 10 : \
+ (n) & (1ULL << 9) ? 9 : \
+ (n) & (1ULL << 8) ? 8 : \
+ (n) & (1ULL << 7) ? 7 : \
+ (n) & (1ULL << 6) ? 6 : \
+ (n) & (1ULL << 5) ? 5 : \
+ (n) & (1ULL << 4) ? 4 : \
+ (n) & (1ULL << 3) ? 3 : \
+ (n) & (1ULL << 2) ? 2 : \
+ (n) & (1ULL << 1) ? 1 : \
+ (n) & (1ULL << 0) ? 0 : \
+ ____ilog2_NaN() \
+ ) : \
+ (sizeof(n) <= 4) ? \
+ __ilog2_u32(n) : \
+ __ilog2_u64(n) \
+ )
+
+#endif /* _LINUX_LOG2_H */
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index cace22b3ac2..18f0e044c43 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3244,7 +3244,7 @@ void *__init alloc_large_system_hash(const char *tablename,
if (numentries > max)
numentries = max;
- log2qty = long_log2(numentries);
+ log2qty = ilog2(numentries);
do {
size = bucketsize << log2qty;
@@ -3266,7 +3266,7 @@ void *__init alloc_large_system_hash(const char *tablename,
printk("%s hash table entries: %d (order: %d, %lu bytes)\n",
tablename,
(1U << log2qty),
- long_log2(size) - PAGE_SHIFT,
+ ilog2(size) - PAGE_SHIFT,
size);
if (_hash_shift)