* Re: "[PATCH] idr.c: extra features enhancements" breaks some archs
2004-04-20 22:52 ` Bartlomiej Zolnierkiewicz
@ 2004-04-20 23:14 ` Andrew Morton
0 siblings, 0 replies; 4+ messages in thread
From: Andrew Morton @ 2004-04-20 23:14 UTC (permalink / raw)
To: Bartlomiej Zolnierkiewicz; +Cc: rmk, jim.houston, linux-arch
Bartlomiej Zolnierkiewicz <B.Zolnierkiewicz@elka.pw.edu.pl> wrote:
>
> On Wednesday 21 of April 2004 00:42, Russell King wrote:
> > On Tue, Apr 20, 2004 at 02:29:47PM -0700, Andrew Morton wrote:
> > > Could I please ask the relevant arch maintainers to prepare an
> > > implementation?
> >
> > Its in the usual place.
>
> I'm talking about find_next_bit() not find_next_zero_bit().
Russell's bk tree now contains an impementation of find_next_bit().
diff -Nru a/arch/arm/lib/findbit.S b/arch/arm/lib/findbit.S
--- a/arch/arm/lib/findbit.S Tue Apr 20 12:58:39 2004
+++ b/arch/arm/lib/findbit.S Tue Apr 20 12:58:39 2004
@@ -51,6 +51,39 @@
add r2, r2, #1 @ align bit pointer
b 2b @ loop for next bit
+/*
+ * Purpose : Find a 'one' bit
+ * Prototype: int find_first_bit(const unsigned long *addr, unsigned int maxbit);
+ */
+ENTRY(_find_first_bit_le)
+ teq r1, #0
+ beq 3f
+ mov r2, #0
+1: ldrb r3, [r0, r2, lsr #3]
+ movs r3, r3
+ bne .found @ any now set - found zero bit
+ add r2, r2, #8 @ next bit pointer
+2: cmp r2, r1 @ any more?
+ blo 1b
+3: mov r0, r1 @ no free bits
+ RETINSTR(mov,pc,lr)
+
+/*
+ * Purpose : Find next 'one' bit
+ * Prototype: int find_next_zero_bit(void *addr, unsigned int maxbit, int offset)
+ */
+ENTRY(_find_next_bit_le)
+ teq r1, #0
+ beq 2b
+ ands ip, r2, #7
+ beq 1b @ If new byte, goto old routine
+ ldrb r3, [r0, r2, lsr #3]
+ movs r3, r3, lsr ip @ shift off unused bits
+ bne .found
+ orr r2, r2, #7 @ if zero, then no bits here
+ add r2, r2, #1 @ align bit pointer
+ b 2b @ loop for next bit
+
#ifdef __ARMEB__
ENTRY(_find_first_zero_bit_be)
@@ -73,6 +106,30 @@
eor r3, r2, #0x18 @ big endian byte ordering
ldrb r3, [r0, r3, lsr #3]
eor r3, r3, #0xff @ now looking for a 1 bit
+ movs r3, r3, lsr ip @ shift off unused bits
+ orreq r2, r2, #7 @ if zero, then no bits here
+ addeq r2, r2, #1 @ align bit pointer
+ beq 2b @ loop for next bit
+
+ENTRY(_find_first_bit_be)
+ teq r1, #0
+ beq 3f
+ mov r2, #0
+1: eor r3, r2, #0x18 @ big endian byte ordering
+ ldrb r3, [r0, r3, lsr #3]
+ movs r3, r3
+ bne .found @ any now set - found zero bit
+ add r2, r2, #8 @ next bit pointer
+2: cmp r2, r1 @ any more?
+ blo 1b
+3: mov r0, r1 @ no free bits
+ RETINSTR(mov,pc,lr)
+
+ENTRY(_find_next_bit_be)
+ ands ip, r2, #7
+ beq 1b @ If new byte, goto old routine
+ eor r3, r2, #0x18 @ big endian byte ordering
+ ldrb r3, [r0, r3, lsr #3]
movs r3, r3, lsr ip @ shift off unused bits
orreq r2, r2, #7 @ if zero, then no bits here
addeq r2, r2, #1 @ align bit pointer
diff -Nru a/include/asm-arm/bitops.h b/include/asm-arm/bitops.h
--- a/include/asm-arm/bitops.h Tue Apr 20 12:58:39 2004
+++ b/include/asm-arm/bitops.h Tue Apr 20 12:58:39 2004
@@ -212,6 +212,8 @@
extern int _test_and_change_bit_le(int nr, volatile unsigned long * p);
extern int _find_first_zero_bit_le(void * p, unsigned size);
extern int _find_next_zero_bit_le(void * p, int size, int offset);
+extern int _find_first_bit_le(const unsigned long *p, unsigned size);
+extern int _find_next_bit_le(const unsigned long *p, int size, int offset);
/*
* Big endian assembly bitops. nr = 0 -> byte 3 bit 0.
@@ -224,7 +226,8 @@
extern int _test_and_change_bit_be(int nr, volatile unsigned long * p);
extern int _find_first_zero_bit_be(void * p, unsigned size);
extern int _find_next_zero_bit_be(void * p, int size, int offset);
-
+extern int _find_first_bit_be(const unsigned long *p, unsigned size);
+extern int _find_next_bit_be(unsigned long *p, int size, int offset);
/*
* The __* form of bitops are non-atomic and may be reordered.
@@ -255,6 +258,8 @@
#define test_bit(nr,p) __test_bit(nr,p)
#define find_first_zero_bit(p,sz) _find_first_zero_bit_le(p,sz)
#define find_next_zero_bit(p,sz,off) _find_next_zero_bit_le(p,sz,off)
+#define find_first_bit(p,sz) _find_first_bit_le(p,sz)
+#define find_next_bit(p,sz,off) _find_next_bit_le(p,sz,off)
#define WORD_BITOFF_TO_LE(x) ((x))
@@ -272,6 +277,8 @@
#define test_bit(nr,p) __test_bit(nr,p)
#define find_first_zero_bit(p,sz) _find_first_zero_bit_be(p,sz)
#define find_next_zero_bit(p,sz,off) _find_next_zero_bit_be(p,sz,off)
+#define find_first_bit(p,sz) _find_first_bit_be(p,sz)
+#define find_next_bit(p,sz,off) _find_next_bit_be(p,sz,off)
#define WORD_BITOFF_TO_LE(x) ((x) ^ 0x18)
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