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author | GuanXuetao <gxt@mprc.pku.edu.cn> | 2011-01-15 18:23:09 +0800 |
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committer | GuanXuetao <gxt@mprc.pku.edu.cn> | 2011-03-17 09:19:13 +0800 |
commit | 96cf5185a95e0b304596fe19edcf8dfcd5c10699 (patch) | |
tree | aebdf44fdfa8841577171df18cb1b0745b54d64e /arch/unicore32 | |
parent | 77c93b2f2388b974253af4149aa025b4751f92ad (diff) | |
download | linux-96cf5185a95e0b304596fe19edcf8dfcd5c10699.tar.gz linux-96cf5185a95e0b304596fe19edcf8dfcd5c10699.tar.bz2 linux-96cf5185a95e0b304596fe19edcf8dfcd5c10699.zip |
unicore32 additional architecture files: low-level lib: misc
This patch implements the rest low-level libraries.
Signed-off-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'arch/unicore32')
-rw-r--r-- | arch/unicore32/include/asm/assembler.h | 131 | ||||
-rw-r--r-- | arch/unicore32/include/asm/bitops.h | 47 | ||||
-rw-r--r-- | arch/unicore32/include/asm/checksum.h | 41 | ||||
-rw-r--r-- | arch/unicore32/include/asm/delay.h | 52 | ||||
-rw-r--r-- | arch/unicore32/include/asm/futex.h | 143 | ||||
-rw-r--r-- | arch/unicore32/include/asm/io.h | 52 | ||||
-rw-r--r-- | arch/unicore32/include/asm/mutex.h | 20 | ||||
-rw-r--r-- | arch/unicore32/lib/Makefile | 27 | ||||
-rw-r--r-- | arch/unicore32/lib/delay.S | 51 | ||||
-rw-r--r-- | arch/unicore32/lib/findbit.S | 98 |
10 files changed, 662 insertions, 0 deletions
diff --git a/arch/unicore32/include/asm/assembler.h b/arch/unicore32/include/asm/assembler.h new file mode 100644 index 000000000000..8e87ed7faeba --- /dev/null +++ b/arch/unicore32/include/asm/assembler.h @@ -0,0 +1,131 @@ +/* + * linux/arch/unicore32/include/asm/assembler.h + * + * Code specific to PKUnity SoC and UniCore ISA + * + * Copyright (C) 2001-2010 GUAN Xue-tao + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Do not include any C declarations in this file - it is included by + * assembler source. + */ +#ifndef __ASSEMBLY__ +#error "Only include this from assembly code" +#endif + +#include <asm/ptrace.h> + +/* + * Little Endian independent macros for shifting bytes within registers. + */ +#define pull >> +#define push << +#define get_byte_0 << #0 +#define get_byte_1 >> #8 +#define get_byte_2 >> #16 +#define get_byte_3 >> #24 +#define put_byte_0 << #0 +#define put_byte_1 << #8 +#define put_byte_2 << #16 +#define put_byte_3 << #24 + +#define cadd cmpadd +#define cand cmpand +#define csub cmpsub +#define cxor cmpxor + +/* + * Enable and disable interrupts + */ + .macro disable_irq, temp + mov \temp, asr + andn \temp, \temp, #0xFF + or \temp, \temp, #PSR_I_BIT | PRIV_MODE + mov.a asr, \temp + .endm + + .macro enable_irq, temp + mov \temp, asr + andn \temp, \temp, #0xFF + or \temp, \temp, #PRIV_MODE + mov.a asr, \temp + .endm + +#define USER(x...) \ +9999: x; \ + .pushsection __ex_table, "a"; \ + .align 3; \ + .long 9999b, 9001f; \ + .popsection + + .macro notcond, cond, nexti = .+8 + .ifc \cond, eq + bne \nexti + .else; .ifc \cond, ne + beq \nexti + .else; .ifc \cond, ea + bub \nexti + .else; .ifc \cond, ub + bea \nexti + .else; .ifc \cond, fs + bns \nexti + .else; .ifc \cond, ns + bfs \nexti + .else; .ifc \cond, fv + bnv \nexti + .else; .ifc \cond, nv + bfv \nexti + .else; .ifc \cond, ua + beb \nexti + .else; .ifc \cond, eb + bua \nexti + .else; .ifc \cond, eg + bsl \nexti + .else; .ifc \cond, sl + beg \nexti + .else; .ifc \cond, sg + bel \nexti + .else; .ifc \cond, el + bsg \nexti + .else; .ifnc \cond, al + .error "Unknown cond in notcond macro argument" + .endif; .endif; .endif; .endif; .endif; .endif; .endif + .endif; .endif; .endif; .endif; .endif; .endif; .endif + .endif + .endm + + .macro usracc, instr, reg, ptr, inc, cond, rept, abort + .rept \rept + notcond \cond, .+8 +9999 : + .if \inc == 1 + \instr\()b.u \reg, [\ptr], #\inc + .elseif \inc == 4 + \instr\()w.u \reg, [\ptr], #\inc + .else + .error "Unsupported inc macro argument" + .endif + + .pushsection __ex_table, "a" + .align 3 + .long 9999b, \abort + .popsection + .endr + .endm + + .macro strusr, reg, ptr, inc, cond = al, rept = 1, abort = 9001f + usracc st, \reg, \ptr, \inc, \cond, \rept, \abort + .endm + + .macro ldrusr, reg, ptr, inc, cond = al, rept = 1, abort = 9001f + usracc ld, \reg, \ptr, \inc, \cond, \rept, \abort + .endm + + .macro nop8 + .rept 8 + nop + .endr + .endm diff --git a/arch/unicore32/include/asm/bitops.h b/arch/unicore32/include/asm/bitops.h new file mode 100644 index 000000000000..1628a6328994 --- /dev/null +++ b/arch/unicore32/include/asm/bitops.h @@ -0,0 +1,47 @@ +/* + * linux/arch/unicore32/include/asm/bitops.h + * + * Code specific to PKUnity SoC and UniCore ISA + * + * Copyright (C) 2001-2010 GUAN Xue-tao + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#ifndef __UNICORE_BITOPS_H__ +#define __UNICORE_BITOPS_H__ + +#define find_next_bit __uc32_find_next_bit +#define find_next_zero_bit __uc32_find_next_zero_bit + +#define find_first_bit __uc32_find_first_bit +#define find_first_zero_bit __uc32_find_first_zero_bit + +#define _ASM_GENERIC_BITOPS_FLS_H_ +#define _ASM_GENERIC_BITOPS___FLS_H_ +#define _ASM_GENERIC_BITOPS_FFS_H_ +#define _ASM_GENERIC_BITOPS___FFS_H_ +/* + * On UNICORE, those functions can be implemented around + * the cntlz instruction for much better code efficiency. + */ + +static inline int fls(int x) +{ + int ret; + + asm("cntlz\t%0, %1" : "=r" (ret) : "r" (x) : "cc"); + ret = 32 - ret; + + return ret; +} + +#define __fls(x) (fls(x) - 1) +#define ffs(x) ({ unsigned long __t = (x); fls(__t & -__t); }) +#define __ffs(x) (ffs(x) - 1) + +#include <asm-generic/bitops.h> + +#endif /* __UNICORE_BITOPS_H__ */ diff --git a/arch/unicore32/include/asm/checksum.h b/arch/unicore32/include/asm/checksum.h new file mode 100644 index 000000000000..f55c3f937c3e --- /dev/null +++ b/arch/unicore32/include/asm/checksum.h @@ -0,0 +1,41 @@ +/* + * linux/arch/unicore32/include/asm/checksum.h + * + * Code specific to PKUnity SoC and UniCore ISA + * + * Copyright (C) 2001-2010 GUAN Xue-tao + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * IP checksum routines + */ +#ifndef __UNICORE_CHECKSUM_H__ +#define __UNICORE_CHECKSUM_H__ + +/* + * computes the checksum of the TCP/UDP pseudo-header + * returns a 16-bit checksum, already complemented + */ + +static inline __wsum +csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len, + unsigned short proto, __wsum sum) +{ + __asm__( + "add.a %0, %1, %2\n" + "addc.a %0, %0, %3\n" + "addc.a %0, %0, %4 << #8\n" + "addc.a %0, %0, %5\n" + "addc %0, %0, #0\n" + : "=&r"(sum) + : "r" (sum), "r" (daddr), "r" (saddr), "r" (len), "Ir" (htons(proto)) + : "cc"); + return sum; +} +#define csum_tcpudp_nofold csum_tcpudp_nofold + +#include <asm-generic/checksum.h> + +#endif diff --git a/arch/unicore32/include/asm/delay.h b/arch/unicore32/include/asm/delay.h new file mode 100644 index 000000000000..164ae61cd6f7 --- /dev/null +++ b/arch/unicore32/include/asm/delay.h @@ -0,0 +1,52 @@ +/* + * linux/arch/unicore32/include/asm/delay.h + * + * Code specific to PKUnity SoC and UniCore ISA + * + * Copyright (C) 2001-2010 GUAN Xue-tao + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Delay routines, using a pre-computed "loops_per_second" value. + */ +#ifndef __UNICORE_DELAY_H__ +#define __UNICORE_DELAY_H__ + +#include <asm/param.h> /* HZ */ + +extern void __delay(int loops); + +/* + * This function intentionally does not exist; if you see references to + * it, it means that you're calling udelay() with an out of range value. + * + * With currently imposed limits, this means that we support a max delay + * of 2000us. Further limits: HZ<=1000 and bogomips<=3355 + */ +extern void __bad_udelay(void); + +/* + * division by multiplication: you don't have to worry about + * loss of precision. + * + * Use only for very small delays ( < 1 msec). Should probably use a + * lookup table, really, as the multiplications take much too long with + * short delays. This is a "reasonable" implementation, though (and the + * first constant multiplications gets optimized away if the delay is + * a constant) + */ +extern void __udelay(unsigned long usecs); +extern void __const_udelay(unsigned long); + +#define MAX_UDELAY_MS 2 + +#define udelay(n) \ + (__builtin_constant_p(n) ? \ + ((n) > (MAX_UDELAY_MS * 1000) ? __bad_udelay() : \ + __const_udelay((n) * ((2199023U*HZ)>>11))) : \ + __udelay(n)) + +#endif /* __UNICORE_DELAY_H__ */ + diff --git a/arch/unicore32/include/asm/futex.h b/arch/unicore32/include/asm/futex.h new file mode 100644 index 000000000000..07dea6170558 --- /dev/null +++ b/arch/unicore32/include/asm/futex.h @@ -0,0 +1,143 @@ +/* + * linux/arch/unicore32/include/asm/futex.h + * + * Code specific to PKUnity SoC and UniCore ISA + * + * Copyright (C) 2001-2010 GUAN Xue-tao + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#ifndef __UNICORE_FUTEX_H__ +#define __UNICORE_FUTEX_H__ + +#ifdef __KERNEL__ + +#include <linux/futex.h> +#include <linux/preempt.h> +#include <linux/uaccess.h> +#include <linux/errno.h> + +#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \ + __asm__ __volatile__( \ + "1: ldw.u %1, [%2]\n" \ + " " insn "\n" \ + "2: stw.u %0, [%2]\n" \ + " mov %0, #0\n" \ + "3:\n" \ + " .pushsection __ex_table,\"a\"\n" \ + " .align 3\n" \ + " .long 1b, 4f, 2b, 4f\n" \ + " .popsection\n" \ + " .pushsection .fixup,\"ax\"\n" \ + "4: mov %0, %4\n" \ + " b 3b\n" \ + " .popsection" \ + : "=&r" (ret), "=&r" (oldval) \ + : "r" (uaddr), "r" (oparg), "Ir" (-EFAULT) \ + : "cc", "memory") + +static inline int +futex_atomic_op_inuser(int encoded_op, int __user *uaddr) +{ + int op = (encoded_op >> 28) & 7; + int cmp = (encoded_op >> 24) & 15; + int oparg = (encoded_op << 8) >> 20; + int cmparg = (encoded_op << 20) >> 20; + int oldval = 0, ret; + + if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) + oparg = 1 << oparg; + + if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) + return -EFAULT; + + pagefault_disable(); /* implies preempt_disable() */ + + switch (op) { + case FUTEX_OP_SET: + __futex_atomic_op("mov %0, %3", ret, oldval, uaddr, oparg); + break; + case FUTEX_OP_ADD: + __futex_atomic_op("add %0, %1, %3", ret, oldval, uaddr, oparg); + break; + case FUTEX_OP_OR: + __futex_atomic_op("or %0, %1, %3", ret, oldval, uaddr, oparg); + break; + case FUTEX_OP_ANDN: + __futex_atomic_op("and %0, %1, %3", + ret, oldval, uaddr, ~oparg); + break; + case FUTEX_OP_XOR: + __futex_atomic_op("xor %0, %1, %3", ret, oldval, uaddr, oparg); + break; + default: + ret = -ENOSYS; + } + + pagefault_enable(); /* subsumes preempt_enable() */ + + if (!ret) { + switch (cmp) { + case FUTEX_OP_CMP_EQ: + ret = (oldval == cmparg); + break; + case FUTEX_OP_CMP_NE: + ret = (oldval != cmparg); + break; + case FUTEX_OP_CMP_LT: + ret = (oldval < cmparg); + break; + case FUTEX_OP_CMP_GE: + ret = (oldval >= cmparg); + break; + case FUTEX_OP_CMP_LE: + ret = (oldval <= cmparg); + break; + case FUTEX_OP_CMP_GT: + ret = (oldval > cmparg); + break; + default: + ret = -ENOSYS; + } + } + return ret; +} + +static inline int +futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval) +{ + int val; + + if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int))) + return -EFAULT; + + pagefault_disable(); /* implies preempt_disable() */ + + __asm__ __volatile__("@futex_atomic_cmpxchg_inatomic\n" + "1: ldw.u %0, [%3]\n" + " cmpxor.a %0, %1\n" + " bne 3f\n" + "2: stw.u %2, [%3]\n" + "3:\n" + " .pushsection __ex_table,\"a\"\n" + " .align 3\n" + " .long 1b, 4f, 2b, 4f\n" + " .popsection\n" + " .pushsection .fixup,\"ax\"\n" + "4: mov %0, %4\n" + " b 3b\n" + " .popsection" + : "=&r" (val) + : "r" (oldval), "r" (newval), "r" (uaddr), "Ir" (-EFAULT) + : "cc", "memory"); + + pagefault_enable(); /* subsumes preempt_enable() */ + + return val; +} + +#endif /* __KERNEL__ */ +#endif /* __UNICORE_FUTEX_H__ */ diff --git a/arch/unicore32/include/asm/io.h b/arch/unicore32/include/asm/io.h new file mode 100644 index 000000000000..d73457c1800a --- /dev/null +++ b/arch/unicore32/include/asm/io.h @@ -0,0 +1,52 @@ +/* + * linux/arch/unicore32/include/asm/io.h + * + * Code specific to PKUnity SoC and UniCore ISA + * + * Copyright (C) 2001-2010 GUAN Xue-tao + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#ifndef __UNICORE_IO_H__ +#define __UNICORE_IO_H__ + +#ifdef __KERNEL__ + +#include <asm/byteorder.h> +#include <asm/memory.h> +#include <asm/system.h> + +#include <asm-generic/io.h> + +/* + * __uc32_ioremap and __uc32_ioremap_cached takes CPU physical address. + */ +extern void __iomem *__uc32_ioremap(unsigned long, size_t); +extern void __iomem *__uc32_ioremap_cached(unsigned long, size_t); +extern void __uc32_iounmap(volatile void __iomem *addr); + +/* + * ioremap and friends. + * + * ioremap takes a PCI memory address, as specified in + * Documentation/IO-mapping.txt. + * + */ +#define ioremap(cookie, size) __uc32_ioremap(cookie, size) +#define ioremap_cached(cookie, size) __uc32_ioremap_cached(cookie, size) +#define iounmap(cookie) __uc32_iounmap(cookie) + +extern void __iomem *ioport_map(unsigned long port, unsigned int nr); +extern void ioport_unmap(void __iomem *addr); + +/* + * Convert a physical pointer to a virtual kernel pointer for /dev/mem + * access + */ +#undef xlate_dev_mem_ptr +#define xlate_dev_mem_ptr(p) __va(p) + +#endif /* __KERNEL__ */ +#endif /* __UNICORE_IO_H__ */ diff --git a/arch/unicore32/include/asm/mutex.h b/arch/unicore32/include/asm/mutex.h new file mode 100644 index 000000000000..fab7d0e8adf6 --- /dev/null +++ b/arch/unicore32/include/asm/mutex.h @@ -0,0 +1,20 @@ +/* + * linux/arch/unicore32/include/asm/mutex.h + * + * Code specific to PKUnity SoC and UniCore ISA + * + * Copyright (C) 2001-2010 GUAN Xue-tao + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * UniCore optimized mutex locking primitives + * + * Please look into asm-generic/mutex-xchg.h for a formal definition. + */ +#ifndef __UNICORE_MUTEX_H__ +#define __UNICORE_MUTEX_H__ + +# include <asm-generic/mutex-xchg.h> +#endif diff --git a/arch/unicore32/lib/Makefile b/arch/unicore32/lib/Makefile new file mode 100644 index 000000000000..87229a558b36 --- /dev/null +++ b/arch/unicore32/lib/Makefile @@ -0,0 +1,27 @@ +# +# linux/arch/unicore32/lib/Makefile +# +# Copyright (C) 2001-2010 GUAN Xue-tao +# + +lib-y := backtrace.o delay.o findbit.o +lib-y += strncpy_from_user.o strnlen_user.o +lib-y += clear_user.o copy_page.o +lib-y += copy_from_user.o copy_to_user.o + +GNU_LIBC_A := $(shell $(CC) $(KBUILD_CFLAGS) -print-file-name=libc.a) +GNU_LIBC_A_OBJS := memchr.o memcpy.o memmove.o memset.o +GNU_LIBC_A_OBJS += strchr.o strrchr.o +GNU_LIBC_A_OBJS += rawmemchr.o # needed by strrchr.o + +GNU_LIBGCC_A := $(shell $(CC) $(KBUILD_CFLAGS) -print-file-name=libgcc.a) +GNU_LIBGCC_A_OBJS := _ashldi3.o _ashrdi3.o _lshrdi3.o +GNU_LIBGCC_A_OBJS += _divsi3.o _modsi3.o _ucmpdi2.o _umodsi3.o _udivsi3.o + +lib-y += $(GNU_LIBC_A_OBJS) $(GNU_LIBGCC_A_OBJS) + +$(addprefix $(obj)/, $(GNU_LIBC_A_OBJS)): + $(Q)$(AR) p $(GNU_LIBC_A) $(notdir $@) > $@ + +$(addprefix $(obj)/, $(GNU_LIBGCC_A_OBJS)): + $(Q)$(AR) p $(GNU_LIBGCC_A) $(notdir $@) > $@ diff --git a/arch/unicore32/lib/delay.S b/arch/unicore32/lib/delay.S new file mode 100644 index 000000000000..24664c009e78 --- /dev/null +++ b/arch/unicore32/lib/delay.S @@ -0,0 +1,51 @@ +/* + * linux/arch/unicore32/lib/delay.S + * + * Code specific to PKUnity SoC and UniCore ISA + * + * Copyright (C) 2001-2010 GUAN Xue-tao + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include <linux/linkage.h> +#include <asm/assembler.h> +#include <asm/param.h> + .text + +.LC0: .word loops_per_jiffy +.LC1: .word (2199023*HZ)>>11 + +/* + * r0 <= 2000 + * lpj <= 0x01ffffff (max. 3355 bogomips) + * HZ <= 1000 + */ + +ENTRY(__udelay) + ldw r2, .LC1 + mul r0, r2, r0 +ENTRY(__const_udelay) @ 0 <= r0 <= 0x7fffff06 + ldw r2, .LC0 + ldw r2, [r2] @ max = 0x01ffffff + mov r0, r0 >> #14 @ max = 0x0001ffff + mov r2, r2 >> #10 @ max = 0x00007fff + mul r0, r2, r0 @ max = 2^32-1 + mov.a r0, r0 >> #6 + cmoveq pc, lr + +/* + * loops = r0 * HZ * loops_per_jiffy / 1000000 + * + * Oh, if only we had a cycle counter... + */ + +@ Delay routine +ENTRY(__delay) + sub.a r0, r0, #2 + bua __delay + mov pc, lr +ENDPROC(__udelay) +ENDPROC(__const_udelay) +ENDPROC(__delay) diff --git a/arch/unicore32/lib/findbit.S b/arch/unicore32/lib/findbit.S new file mode 100644 index 000000000000..c360ce905d8b --- /dev/null +++ b/arch/unicore32/lib/findbit.S @@ -0,0 +1,98 @@ +/* + * linux/arch/unicore32/lib/findbit.S + * + * Code specific to PKUnity SoC and UniCore ISA + * + * Copyright (C) 2001-2010 GUAN Xue-tao + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include <linux/linkage.h> +#include <asm/assembler.h> + .text + +/* + * Purpose : Find a 'zero' bit + * Prototype: int find_first_zero_bit(void *addr, unsigned int maxbit); + */ +__uc32_find_first_zero_bit: + cxor.a r1, #0 + beq 3f + mov r2, #0 +1: ldb r3, [r0+], r2 >> #3 + xor.a r3, r3, #0xff @ invert bits + bne .L_found @ any now set - found zero bit + add r2, r2, #8 @ next bit pointer +2: csub.a r2, r1 @ any more? + bub 1b +3: mov r0, r1 @ no free bits + mov pc, lr + +/* + * Purpose : Find next 'zero' bit + * Prototype: int find_next_zero_bit + * (void *addr, unsigned int maxbit, int offset) + */ +ENTRY(__uc32_find_next_zero_bit) + cxor.a r1, #0 + beq 3b + and.a ip, r2, #7 + beq 1b @ If new byte, goto old routine + ldb r3, [r0+], r2 >> #3 + xor r3, r3, #0xff @ now looking for a 1 bit + mov.a r3, r3 >> ip @ shift off unused bits + bne .L_found + or r2, r2, #7 @ if zero, then no bits here + add r2, r2, #1 @ align bit pointer + b 2b @ loop for next bit +ENDPROC(__uc32_find_next_zero_bit) + +/* + * Purpose : Find a 'one' bit + * Prototype: int find_first_bit + * (const unsigned long *addr, unsigned int maxbit); + */ +__uc32_find_first_bit: + cxor.a r1, #0 + beq 3f + mov r2, #0 +1: ldb r3, [r0+], r2 >> #3 + mov.a r3, r3 + bne .L_found @ any now set - found zero bit + add r2, r2, #8 @ next bit pointer +2: csub.a r2, r1 @ any more? + bub 1b +3: mov r0, r1 @ no free bits + mov pc, lr + +/* + * Purpose : Find next 'one' bit + * Prototype: int find_next_zero_bit + * (void *addr, unsigned int maxbit, int offset) + */ +ENTRY(__uc32_find_next_bit) + cxor.a r1, #0 + beq 3b + and.a ip, r2, #7 + beq 1b @ If new byte, goto old routine + ldb r3, [r0+], r2 >> #3 + mov.a r3, r3 >> ip @ shift off unused bits + bne .L_found + or r2, r2, #7 @ if zero, then no bits here + add r2, r2, #1 @ align bit pointer + b 2b @ loop for next bit +ENDPROC(__uc32_find_next_bit) + +/* + * One or more bits in the LSB of r3 are assumed to be set. + */ +.L_found: + rsub r1, r3, #0 + and r3, r3, r1 + cntlz r3, r3 + rsub r3, r3, #31 + add r0, r2, r3 + mov pc, lr + |