mirror of
https://gitlab.rtems.org/rtems/rtos/rtems.git
synced 2026-09-21 22:44:02 +08:00
(_CPU_Bitfield_Find_first_bit, _CPU_Priority_Mask, _CPU_Priority_bits_index): Remove.
This commit is contained in:
Ralf Corsepius
@@ -636,92 +636,6 @@ void _BSP_Fatal_error(unsigned int);
|
||||
|
||||
/* end of Fatal Error manager macros */
|
||||
|
||||
/* Bitfield handler macros */
|
||||
|
||||
/*
|
||||
* This routine sets _output to the bit number of the first bit
|
||||
* set in _value. _value is of CPU dependent type Priority_Bit_map_control.
|
||||
* This type may be either 16 or 32 bits wide although only the 16
|
||||
* least significant bits will be used.
|
||||
*
|
||||
* There are a number of variables in using a "find first bit" type
|
||||
* instruction.
|
||||
*
|
||||
* (1) What happens when run on a value of zero?
|
||||
* (2) Bits may be numbered from MSB to LSB or vice-versa.
|
||||
* (3) The numbering may be zero or one based.
|
||||
* (4) The "find first bit" instruction may search from MSB or LSB.
|
||||
*
|
||||
* RTEMS guarantees that (1) will never happen so it is not a concern.
|
||||
* (2),(3), (4) are handled by the macros _CPU_Priority_mask() and
|
||||
* _CPU_Priority_Bits_index(). These three form a set of routines
|
||||
* which must logically operate together. Bits in the _value are
|
||||
* set and cleared based on masks built by _CPU_Priority_mask().
|
||||
* The basic major and minor values calculated by _Priority_Major()
|
||||
* and _Priority_Minor() are "massaged" by _CPU_Priority_Bits_index()
|
||||
* to properly range between the values returned by the "find first bit"
|
||||
* instruction. This makes it possible for _Priority_Get_highest() to
|
||||
* calculate the major and directly index into the minor table.
|
||||
* This mapping is necessary to ensure that 0 (a high priority major/minor)
|
||||
* is the first bit found.
|
||||
*
|
||||
* This entire "find first bit" and mapping process depends heavily
|
||||
* on the manner in which a priority is broken into a major and minor
|
||||
* components with the major being the 4 MSB of a priority and minor
|
||||
* the 4 LSB. Thus (0 << 4) + 0 corresponds to priority 0 -- the highest
|
||||
* priority. And (15 << 4) + 14 corresponds to priority 254 -- the next
|
||||
* to the lowest priority.
|
||||
*
|
||||
* If your CPU does not have a "find first bit" instruction, then
|
||||
* there are ways to make do without it. Here are a handful of ways
|
||||
* to implement this in software:
|
||||
*
|
||||
* - a series of 16 bit test instructions
|
||||
* - a "binary search using if's"
|
||||
* - _number = 0
|
||||
* if _value > 0x00ff
|
||||
* _value >>=8
|
||||
* _number = 8;
|
||||
*
|
||||
* if _value > 0x0000f
|
||||
* _value >=8
|
||||
* _number += 4
|
||||
*
|
||||
* _number += bit_set_table[ _value ]
|
||||
*
|
||||
* where bit_set_table[ 16 ] has values which indicate the first
|
||||
* bit set
|
||||
*/
|
||||
|
||||
#define _CPU_Bitfield_Find_first_bit( _value, _output ) \
|
||||
{ \
|
||||
asm volatile ("cntlzw %0, %1" : "=r" ((_output)), "=r" ((_value)) : \
|
||||
"1" ((_value))); \
|
||||
}
|
||||
|
||||
/* end of Bitfield handler macros */
|
||||
|
||||
/*
|
||||
* This routine builds the mask which corresponds to the bit fields
|
||||
* as searched by _CPU_Bitfield_Find_first_bit(). See the discussion
|
||||
* for that routine.
|
||||
*/
|
||||
|
||||
#define _CPU_Priority_Mask( _bit_number ) \
|
||||
( 0x80000000 >> (_bit_number) )
|
||||
|
||||
/*
|
||||
* This routine translates the bit numbers returned by
|
||||
* _CPU_Bitfield_Find_first_bit() into something suitable for use as
|
||||
* a major or minor component of a priority. See the discussion
|
||||
* for that routine.
|
||||
*/
|
||||
|
||||
#define _CPU_Priority_bits_index( _priority ) \
|
||||
(_priority)
|
||||
|
||||
/* end of Priority handler macros */
|
||||
|
||||
/*
|
||||
* Until all new-exception processing BSPs have fixed
|
||||
* PR288, we let the good BSPs pass
|
||||
|
||||
@@ -808,91 +808,6 @@ void _CPU_ISR_install_raw_handler(
|
||||
|
||||
/* end of Fatal Error manager macros */
|
||||
|
||||
/* Bitfield handler macros */
|
||||
|
||||
/*
|
||||
* This routine sets _output to the bit number of the first bit
|
||||
* set in _value. _value is of CPU dependent type Priority_Bit_map_control.
|
||||
* This type may be either 16 or 32 bits wide although only the 16
|
||||
* least significant bits will be used.
|
||||
*
|
||||
* There are a number of variables in using a "find first bit" type
|
||||
* instruction.
|
||||
*
|
||||
* (1) What happens when run on a value of zero?
|
||||
* (2) Bits may be numbered from MSB to LSB or vice-versa.
|
||||
* (3) The numbering may be zero or one based.
|
||||
* (4) The "find first bit" instruction may search from MSB or LSB.
|
||||
*
|
||||
* RTEMS guarantees that (1) will never happen so it is not a concern.
|
||||
* (2),(3), (4) are handled by the macros _CPU_Priority_mask() and
|
||||
* _CPU_Priority_Bits_index(). These three form a set of routines
|
||||
* which must logically operate together. Bits in the _value are
|
||||
* set and cleared based on masks built by _CPU_Priority_mask().
|
||||
* The basic major and minor values calculated by _Priority_Major()
|
||||
* and _Priority_Minor() are "massaged" by _CPU_Priority_Bits_index()
|
||||
* to properly range between the values returned by the "find first bit"
|
||||
* instruction. This makes it possible for _Priority_Get_highest() to
|
||||
* calculate the major and directly index into the minor table.
|
||||
* This mapping is necessary to ensure that 0 (a high priority major/minor)
|
||||
* is the first bit found.
|
||||
*
|
||||
* This entire "find first bit" and mapping process depends heavily
|
||||
* on the manner in which a priority is broken into a major and minor
|
||||
* components with the major being the 4 MSB of a priority and minor
|
||||
* the 4 LSB. Thus (0 << 4) + 0 corresponds to priority 0 -- the highest
|
||||
* priority. And (15 << 4) + 14 corresponds to priority 254 -- the next
|
||||
* to the lowest priority.
|
||||
*
|
||||
* If your CPU does not have a "find first bit" instruction, then
|
||||
* there are ways to make do without it. Here are a handful of ways
|
||||
* to implement this in software:
|
||||
*
|
||||
* - a series of 16 bit test instructions
|
||||
* - a "binary search using if's"
|
||||
* - _number = 0
|
||||
* if _value > 0x00ff
|
||||
* _value >>=8
|
||||
* _number = 8;
|
||||
*
|
||||
* if _value > 0x0000f
|
||||
* _value >=8
|
||||
* _number += 4
|
||||
*
|
||||
* _number += bit_set_table[ _value ]
|
||||
*
|
||||
* where bit_set_table[ 16 ] has values which indicate the first
|
||||
* bit set
|
||||
*/
|
||||
|
||||
#define _CPU_Bitfield_Find_first_bit( _value, _output ) \
|
||||
{ \
|
||||
asm volatile ("cntlzw %0, %1" : "=r" ((_output)), "=r" ((_value)) : \
|
||||
"1" ((_value))); \
|
||||
}
|
||||
|
||||
/* end of Bitfield handler macros */
|
||||
|
||||
/*
|
||||
* This routine builds the mask which corresponds to the bit fields
|
||||
* as searched by _CPU_Bitfield_Find_first_bit(). See the discussion
|
||||
* for that routine.
|
||||
*/
|
||||
|
||||
#define _CPU_Priority_Mask( _bit_number ) \
|
||||
( 0x80000000 >> (_bit_number) )
|
||||
|
||||
/*
|
||||
* This routine translates the bit numbers returned by
|
||||
* _CPU_Bitfield_Find_first_bit() into something suitable for use as
|
||||
* a major or minor component of a priority. See the discussion
|
||||
* for that routine.
|
||||
*/
|
||||
|
||||
#define _CPU_Priority_bits_index( _priority ) \
|
||||
(_priority)
|
||||
|
||||
/* end of Priority handler macros */
|
||||
|
||||
#ifdef __cplusplus
|
||||
}
|
||||
|
||||
Reference in New Issue
Block a user