This change to use generic bitrev8() for bmac driver.
Signed-off-by: yalin wang <[email protected]>
---
drivers/net/ethernet/apple/bmac.c | 17 +++--------------
1 file changed, 3 insertions(+), 14 deletions(-)
diff --git a/drivers/net/ethernet/apple/bmac.c b/drivers/net/ethernet/apple/bmac.c
index a65d7a6..e749747 100644
--- a/drivers/net/ethernet/apple/bmac.c
+++ b/drivers/net/ethernet/apple/bmac.c
@@ -22,6 +22,7 @@
#include <linux/bitrev.h>
#include <linux/ethtool.h>
#include <linux/slab.h>
+#include <linux/bitrev.h>
#include <asm/prom.h>
#include <asm/dbdma.h>
#include <asm/io.h>
@@ -805,18 +806,6 @@ static irqreturn_t bmac_txdma_intr(int irq, void *dev_id)
}
#ifndef SUNHME_MULTICAST
-/* Real fast bit-reversal algorithm, 6-bit values */
-static int reverse6[64] = {
- 0x0,0x20,0x10,0x30,0x8,0x28,0x18,0x38,
- 0x4,0x24,0x14,0x34,0xc,0x2c,0x1c,0x3c,
- 0x2,0x22,0x12,0x32,0xa,0x2a,0x1a,0x3a,
- 0x6,0x26,0x16,0x36,0xe,0x2e,0x1e,0x3e,
- 0x1,0x21,0x11,0x31,0x9,0x29,0x19,0x39,
- 0x5,0x25,0x15,0x35,0xd,0x2d,0x1d,0x3d,
- 0x3,0x23,0x13,0x33,0xb,0x2b,0x1b,0x3b,
- 0x7,0x27,0x17,0x37,0xf,0x2f,0x1f,0x3f
-};
-
static unsigned int
crc416(unsigned int curval, unsigned short nxtval)
{
@@ -871,7 +860,7 @@ bmac_addhash(struct bmac_data *bp, unsigned char *addr)
if (!(*addr)) return;
crc = bmac_crc((unsigned short *)addr) & 0x3f; /* Big-endian alert! */
- crc = reverse6[crc]; /* Hyperfast bit-reversing algorithm */
+ crc = bitrev8((u8)crc);
if (bp->hash_use_count[crc]++) return; /* This bit is already set */
mask = crc % 16;
mask = (unsigned char)1 << mask;
@@ -886,7 +875,7 @@ bmac_removehash(struct bmac_data *bp, unsigned char *addr)
/* Now, delete the address from the filter copy, as indicated */
crc = bmac_crc((unsigned short *)addr) & 0x3f; /* Big-endian alert! */
- crc = reverse6[crc]; /* Hyperfast bit-reversing algorithm */
+ crc = bitrev8((u8)crc);
if (bp->hash_use_count[crc] == 0) return; /* That bit wasn't in use! */
if (--bp->hash_use_count[crc]) return; /* That bit is still in use */
mask = crc % 16;
--
1.9.1
On 2015-08-10 at 11:53:41 +0200, yalin wang <[email protected]> wrote:
> This change to use generic bitrev8() for bmac driver.
>
> Signed-off-by: yalin wang <[email protected]>
> ---
> drivers/net/ethernet/apple/bmac.c | 17 +++--------------
> 1 file changed, 3 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/net/ethernet/apple/bmac.c b/drivers/net/ethernet/apple/bmac.c
> index a65d7a6..e749747 100644
> --- a/drivers/net/ethernet/apple/bmac.c
> +++ b/drivers/net/ethernet/apple/bmac.c
> @@ -22,6 +22,7 @@
> #include <linux/bitrev.h>
> #include <linux/ethtool.h>
> #include <linux/slab.h>
> +#include <linux/bitrev.h>
> #include <asm/prom.h>
> #include <asm/dbdma.h>
> #include <asm/io.h>
> @@ -805,18 +806,6 @@ static irqreturn_t bmac_txdma_intr(int irq, void *dev_id)
> }
>
> #ifndef SUNHME_MULTICAST
> -/* Real fast bit-reversal algorithm, 6-bit values */
> -static int reverse6[64] = {
> - 0x0,0x20,0x10,0x30,0x8,0x28,0x18,0x38,
> - 0x4,0x24,0x14,0x34,0xc,0x2c,0x1c,0x3c,
> - 0x2,0x22,0x12,0x32,0xa,0x2a,0x1a,0x3a,
> - 0x6,0x26,0x16,0x36,0xe,0x2e,0x1e,0x3e,
> - 0x1,0x21,0x11,0x31,0x9,0x29,0x19,0x39,
> - 0x5,0x25,0x15,0x35,0xd,0x2d,0x1d,0x3d,
> - 0x3,0x23,0x13,0x33,0xb,0x2b,0x1b,0x3b,
> - 0x7,0x27,0x17,0x37,0xf,0x2f,0x1f,0x3f
> -};
> -
> static unsigned int
> crc416(unsigned int curval, unsigned short nxtval)
> {
> @@ -871,7 +860,7 @@ bmac_addhash(struct bmac_data *bp, unsigned char *addr)
>
> if (!(*addr)) return;
> crc = bmac_crc((unsigned short *)addr) & 0x3f; /* Big-endian alert! */
> - crc = reverse6[crc]; /* Hyperfast bit-reversing algorithm */
> + crc = bitrev8((u8)crc);
No, this won't work. reverse6 works on 6 bit values, while bitrev8 works
on 8bit values, e.g. reverse6[1] = 0x20, while bitrev8(1) = 0x80
> From: Tobias Klauser
> Sent: 10 August 2015 12:49
> On 2015-08-10 at 11:53:41 +0200, yalin wang <[email protected]> wrote:
> > This change to use generic bitrev8() for bmac driver.
...
> > @@ -871,7 +860,7 @@ bmac_addhash(struct bmac_data *bp, unsigned char *addr)
> >
> > if (!(*addr)) return;
> > crc = bmac_crc((unsigned short *)addr) & 0x3f; /* Big-endian alert! */
Why not *((u8 *)addr + 1) & 0x3f
> > - crc = reverse6[crc]; /* Hyperfast bit-reversing algorithm */
> > + crc = bitrev8((u8)crc);
>
> No, this won't work. reverse6 works on 6 bit values, while bitrev8 works
> on 8bit values, e.g. reverse6[1] = 0x20, while bitrev8(1) = 0x80
You could use bitrev8(n) >> 2.
But that is a 'strange' map of a 7-bit value to a 6-bit one.
I thought it was more common for ethernet hardware to use the
value of the crc register after all 6 bytes of the mac address
had been processed.
David
> On Aug 10, 2015, at 20:02, David Laight <[email protected]> wrote:
>
>> From: Tobias Klauser
>> Sent: 10 August 2015 12:49
>> On 2015-08-10 at 11:53:41 +0200, yalin wang <[email protected]> wrote:
>>> This change to use generic bitrev8() for bmac driver.
> ...
>>> @@ -871,7 +860,7 @@ bmac_addhash(struct bmac_data *bp, unsigned char *addr)
>>>
>>> if (!(*addr)) return;
>>> crc = bmac_crc((unsigned short *)addr) & 0x3f; /* Big-endian alert! */
>
> Why not *((u8 *)addr + 1) & 0x3f
>
>>> - crc = reverse6[crc]; /* Hyperfast bit-reversing algorithm */
>>> + crc = bitrev8((u8)crc);
>>
>> No, this won't work. reverse6 works on 6 bit values, while bitrev8 works
>> on 8bit values, e.g. reverse6[1] = 0x20, while bitrev8(1) = 0x80
>
> You could use bitrev8(n) >> 2.
>
> But that is a 'strange' map of a 7-bit value to a 6-bit one.
>
> I thought it was more common for ethernet hardware to use the
> value of the crc register after all 6 bytes of the mac address
> had been processed.
oh, my mistake, i will change it in V2 for review.-
This change to use generic bitrev8() for bmac driver.
Signed-off-by: yalin wang <[email protected]>
---
drivers/net/ethernet/apple/bmac.c | 17 +++--------------
1 file changed, 3 insertions(+), 14 deletions(-)
diff --git a/drivers/net/ethernet/apple/bmac.c b/drivers/net/ethernet/apple/bmac.c
index a65d7a6..7f7a398 100644
--- a/drivers/net/ethernet/apple/bmac.c
+++ b/drivers/net/ethernet/apple/bmac.c
@@ -22,6 +22,7 @@
#include <linux/bitrev.h>
#include <linux/ethtool.h>
#include <linux/slab.h>
+#include <linux/bitrev.h>
#include <asm/prom.h>
#include <asm/dbdma.h>
#include <asm/io.h>
@@ -805,18 +806,6 @@ static irqreturn_t bmac_txdma_intr(int irq, void *dev_id)
}
#ifndef SUNHME_MULTICAST
-/* Real fast bit-reversal algorithm, 6-bit values */
-static int reverse6[64] = {
- 0x0,0x20,0x10,0x30,0x8,0x28,0x18,0x38,
- 0x4,0x24,0x14,0x34,0xc,0x2c,0x1c,0x3c,
- 0x2,0x22,0x12,0x32,0xa,0x2a,0x1a,0x3a,
- 0x6,0x26,0x16,0x36,0xe,0x2e,0x1e,0x3e,
- 0x1,0x21,0x11,0x31,0x9,0x29,0x19,0x39,
- 0x5,0x25,0x15,0x35,0xd,0x2d,0x1d,0x3d,
- 0x3,0x23,0x13,0x33,0xb,0x2b,0x1b,0x3b,
- 0x7,0x27,0x17,0x37,0xf,0x2f,0x1f,0x3f
-};
-
static unsigned int
crc416(unsigned int curval, unsigned short nxtval)
{
@@ -871,7 +860,7 @@ bmac_addhash(struct bmac_data *bp, unsigned char *addr)
if (!(*addr)) return;
crc = bmac_crc((unsigned short *)addr) & 0x3f; /* Big-endian alert! */
- crc = reverse6[crc]; /* Hyperfast bit-reversing algorithm */
+ crc = bitrev8((u8)crc) >> 2;
if (bp->hash_use_count[crc]++) return; /* This bit is already set */
mask = crc % 16;
mask = (unsigned char)1 << mask;
@@ -886,7 +875,7 @@ bmac_removehash(struct bmac_data *bp, unsigned char *addr)
/* Now, delete the address from the filter copy, as indicated */
crc = bmac_crc((unsigned short *)addr) & 0x3f; /* Big-endian alert! */
- crc = reverse6[crc]; /* Hyperfast bit-reversing algorithm */
+ crc = bitrev8((u8)crc) >> 2;
if (bp->hash_use_count[crc] == 0) return; /* That bit wasn't in use! */
if (--bp->hash_use_count[crc]) return; /* That bit is still in use */
mask = crc % 16;
--
1.9.1