/*
* Bit operations for the Hexagon architecture
*
* Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*/

#ifndef _ASM_BITOPS_H
#define _ASM_BITOPS_H

#include <linux/compiler.h>
#include <asm/byteorder.h>
#include <asm/atomic.h>

#ifdef __KERNEL__

#define smp_mb__before_clear_bit() barrier()
#define smp_mb__after_clear_bit() barrier()

/*
* The offset calculations for these are based on BITS_PER_LONG == 32
* (i.e. I get to shift by #5-2 (32 bits per long, 4 bytes per access),
* mask by 0x0000001F)
*
* Typically, R10 is clobbered for address, R11 bit nr, and R12 is temp
*/

/**
* test_and_clear_bit - clear a bit and return its old value
* @nr: bit number to clear
* @addr: pointer to memory
*/
static inline int test_and_clear_bit(int nr, volatile void *addr)
{
int oldval;

__asm__ __volatile__ (
" {R10 = %1; R11 = asr(%2,#5); }\n"
" {R10 += asl(R11,#2); R11 = and(%2,#0x1f)}\n"
"1: R12 = memw_locked(R10);\n"
" { P0 = tstbit(R12,R11); R12 = clrbit(R12,R11); }\n"
" memw_locked(R10,P1) = R12;\n"
" {if !P1 jump 1b; %0 = mux(P0,#1,#0);}\n"
: "=&r" (oldval)
: "r" (addr), "r" (nr)
: "r10", "r11", "r12", "p0", "p1", "memory"
);

return oldval;
}

/**
* test_and_set_bit - set a bit and return its old value
* @nr: bit number to set
* @addr: pointer to memory
*/
static inline int test_and_set_bit(int nr, volatile void *addr)
{
int oldval;

__asm__ __volatile__ (
" {R10 = %1; R11 = asr(%2,#5); }\n"
" {R10 += asl(R11,#2); R11 = and(%2,#0x1f)}\n"
"1: R12 = memw_locked(R10);\n"
" { P0 = tstbit(R12,R11); R12 = setbit(R12,R11); }\n"
" memw_locked(R10,P1) = R12;\n"
" {if !P1 jump 1b; %0 = mux(P0,#1,#0);}\n"
: "=&r" (oldval)
: "r" (addr), "r" (nr)
: "r10", "r11", "r12", "p0", "p1", "memory"
);


return oldval;

}

/**
* test_and_change_bit - toggle a bit and return its old value
* @nr: bit number to set
* @addr: pointer to memory
*/
static inline int test_and_change_bit(int nr, volatile void *addr)
{
int oldval;

__asm__ __volatile__ (
" {R10 = %1; R11 = asr(%2,#5); }\n"
" {R10 += asl(R11,#2); R11 = and(%2,#0x1f)}\n"
"1: R12 = memw_locked(R10);\n"
" { P0 = tstbit(R12,R11); R12 = togglebit(R12,R11); }\n"
" memw_locked(R10,P1) = R12;\n"
" {if !P1 jump 1b; %0 = mux(P0,#1,#0);}\n"
: "=&r" (oldval)
: "r" (addr), "r" (nr)
: "r10", "r11", "r12", "p0", "p1", "memory"
);

return oldval;

}

/*
* Atomic, but doesn't care about the return value.
* Rewrite later to save a cycle or two.
*/

static inline void clear_bit(int nr, volatile void *addr)
{
test_and_clear_bit(nr, addr);
}

static inline void set_bit(int nr, volatile void *addr)
{
test_and_set_bit(nr, addr);
}

static inline void change_bit(int nr, volatile void *addr)
{
test_and_change_bit(nr, addr);
}


/*
* These are allowed to be non-atomic. In fact the generic flavors are
* in non-atomic.h. Would it be better to use intrinsics for this?
*
* OK, writes in our architecture do not invalidate LL/SC, so this has to
* be atomic, particularly for things like slab_lock and slab_unlock.
*
*/
static inline void __clear_bit(int nr, volatile unsigned long *addr)
{
test_and_clear_bit(nr, addr);
}

static inline void __set_bit(int nr, volatile unsigned long *addr)
{
test_and_set_bit(nr, addr);
}

static inline void __change_bit(int nr, volatile unsigned long *addr)
{
test_and_change_bit(nr, addr);
}

/* Apparently, at least some of these are allowed to be non-atomic */
static inline int __test_and_clear_bit(int nr, volatile unsigned long *addr)
{
return test_and_clear_bit(nr, addr);
}

static inline int __test_and_set_bit(int nr, volatile unsigned long *addr)
{
return test_and_set_bit(nr, addr);
}

static inline int __test_and_change_bit(int nr, volatile unsigned long *addr)
{
return test_and_change_bit(nr, addr);
}

static inline int __test_bit(int nr, const volatile unsigned long *addr)
{
int retval;

asm volatile(
"{P0 = tstbit(%1,%2); if (P0.new) %0 = #1; if (!P0.new) %0 = #0;}\n"
: "=&r" (retval)
: "r" (addr[BIT_WORD(nr)]), "r" (nr % BITS_PER_LONG)
: "p0"
);

return retval;
}

#define test_bit(nr, addr) __test_bit(nr, addr)

/*
* ffz - find first zero in word.
* @word: The word to search
*
* Undefined if no zero exists, so code should check against ~0UL first.
*/
static inline long ffz(int x)
{
int r;

asm("%0 = ct1(%1);\n"
: "=&r" (r)
: "r" (x));
return r;
}

/*
* fls - find last (most-significant) bit set
* @x: the word to search
*
* This is defined the same way as ffs.
* Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
*/
static inline long fls(int x)
{
int r;

asm("{ %0 = cl0(%1);}\n"
"%0 = sub(#32,%0);\n"
: "=&r" (r)
: "r" (x)
: "p0");

return r;
}

/*
* ffs - find first bit set
* @x: the word to search
*
* This is defined the same way as
* the libc and compiler builtin ffs routines, therefore
* differs in spirit from the above ffz (man ffs).
*/
static inline long ffs(int x)
{
int r;

asm("{ P0 = cmp.eq(%1,#0); %0 = ct0(%1);}\n"
"{ if P0 %0 = #0; if !P0 %0 = add(%0,#1);}\n"
: "=&r" (r)
: "r" (x)
: "p0");

return r;
}

/*
* __ffs - find first bit in word.
* @word: The word to search
*
* Undefined if no bit exists, so code should check against 0 first.
*
* bits_per_long assumed to be 32
* numbering starts at 0 I think (instead of 1 like ffs)
*/
static inline unsigned long __ffs(unsigned long word)
{
int num;

asm("%0 = ct0(%1);\n"
: "=&r" (num)
: "r" (word));

return num;
}

/*
* __fls - find last (most-significant) set bit in a long word
* @word: the word to search
*
* Undefined if no set bit exists, so code should check against 0 first.
* bits_per_long assumed to be 32
*/
static inline unsigned long __fls(unsigned long word)
{
int num;

asm("%0 = cl0(%1);\n"
"%0 = sub(#31,%0);\n"
: "=&r" (num)
: "r" (word));

return num;
}

#include <asm-generic/bitops/lock.h>
#include <asm-generic/bitops/find.h>

#include <asm-generic/bitops/fls64.h>
#include <asm-generic/bitops/sched.h>
#include <asm-generic/bitops/hweight.h>

#include <asm-generic/bitops/le.h>
#include <asm-generic/bitops/ext2-atomic.h>

#endif /* __KERNEL__ */
#endif