blob: 644e54e6f7b96e596b9c08398ea5f32c28178b07 (
plain) (
tree)
|
|
/**
* @file
*
* @ingroup ScoreTLS
*
* @brief Thread-Local Storage (TLS)
*/
/*
* Copyright (c) 2014 embedded brains GmbH. All rights reserved.
*
* embedded brains GmbH
* Dornierstr. 4
* 82178 Puchheim
* Germany
* <rtems@embedded-brains.de>
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
#ifndef _RTEMS_SCORE_TLS_H
#define _RTEMS_SCORE_TLS_H
#include <rtems/score/cpu.h>
#include <string.h>
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
/**
* @defgroup ScoreTLS Thread-Local Storage (TLS)
*
* @ingroup Score
*
* @brief Thread-local storage (TLS) support.
*
* Variants I and II are according to Ulrich Drepper, "ELF Handling For
* Thread-Local Storage".
*
* @{
*/
extern char _TLS_Data_begin[];
extern char _TLS_Data_end[];
extern char _TLS_Data_size[];
extern char _TLS_BSS_begin[];
extern char _TLS_BSS_end[];
extern char _TLS_BSS_size[];
extern char _TLS_Size[];
extern char _TLS_Alignment[];
typedef struct {
/*
* FIXME: Not sure if the generation number type is correct for all
* architectures.
*/
uint32_t generation_number;
void *tls_blocks[1];
} TLS_Dynamic_thread_vector;
typedef struct TLS_Thread_control_block {
#ifdef __i386__
struct TLS_Thread_control_block *tcb;
#else
TLS_Dynamic_thread_vector *dtv;
uintptr_t reserved;
#endif
} TLS_Thread_control_block;
typedef struct {
uintptr_t module;
uintptr_t offset;
} TLS_Index;
static inline uintptr_t _TLS_Get_size( void )
{
/*
* Do not use _TLS_Size here since this will lead GCC to assume that this
* symbol is not 0 and the tests for 0 will be optimized away.
*/
return (uintptr_t) _TLS_BSS_end - (uintptr_t) _TLS_Data_begin;
}
static inline uintptr_t _TLS_Heap_align_up( uintptr_t val )
{
uintptr_t msk = CPU_HEAP_ALIGNMENT - 1;
return (val + msk) & ~msk;
}
static inline uintptr_t _TLS_Get_thread_control_block_area_size(
uintptr_t alignment
)
{
return alignment <= sizeof(TLS_Thread_control_block) ?
sizeof(TLS_Thread_control_block) : alignment;
}
static inline uintptr_t _TLS_Get_allocation_size(
uintptr_t size,
uintptr_t alignment
)
{
uintptr_t allocation_size = 0;
allocation_size += _TLS_Heap_align_up( size );
allocation_size += _TLS_Get_thread_control_block_area_size( alignment );
#ifndef __i386__
allocation_size += sizeof(TLS_Dynamic_thread_vector);
#endif
return allocation_size;
}
static inline void *_TLS_Copy_and_clear( void *tls_area )
{
tls_area = memcpy(
tls_area,
_TLS_Data_begin,
(size_t) ((uintptr_t)_TLS_Data_size)
);
memset(
(char *) tls_area + (size_t)((intptr_t) _TLS_BSS_begin) -
(size_t)((intptr_t) _TLS_Data_begin),
0,
((size_t) (intptr_t)_TLS_BSS_size)
);
return tls_area;
}
static inline void *_TLS_Initialize(
void *tls_block,
TLS_Thread_control_block *tcb,
TLS_Dynamic_thread_vector *dtv
)
{
#ifdef __i386__
(void) dtv;
tcb->tcb = tcb;
#else
tcb->dtv = dtv;
dtv->generation_number = 1;
dtv->tls_blocks[0] = tls_block;
#endif
return _TLS_Copy_and_clear( tls_block );
}
/* Use Variant I, TLS offsets emitted by linker takes the TCB into account */
static inline void *_TLS_TCB_at_area_begin_initialize( void *tls_area )
{
void *tls_block = (char *) tls_area
+ _TLS_Get_thread_control_block_area_size( (uintptr_t) _TLS_Alignment );
TLS_Thread_control_block *tcb = tls_area;
uintptr_t aligned_size = _TLS_Heap_align_up( (uintptr_t) _TLS_Size );
TLS_Dynamic_thread_vector *dtv = (TLS_Dynamic_thread_vector *)
((char *) tls_block + aligned_size);
return _TLS_Initialize( tls_block, tcb, dtv );
}
/* Use Variant I, TLS offsets emitted by linker neglects the TCB */
static inline void *_TLS_TCB_before_TLS_block_initialize( void *tls_area )
{
void *tls_block = (char *) tls_area
+ _TLS_Get_thread_control_block_area_size( (uintptr_t) _TLS_Alignment );
TLS_Thread_control_block *tcb = (TLS_Thread_control_block *)
((char *) tls_block - sizeof(*tcb));
uintptr_t aligned_size = _TLS_Heap_align_up( (uintptr_t) _TLS_Size );
TLS_Dynamic_thread_vector *dtv = (TLS_Dynamic_thread_vector *)
((char *) tls_block + aligned_size);
return _TLS_Initialize( tls_block, tcb, dtv );
}
/* Use Variant II */
static inline void *_TLS_TCB_after_TLS_block_initialize( void *tls_area )
{
uintptr_t size = (uintptr_t) _TLS_Size;
uintptr_t tls_align = (uintptr_t) _TLS_Alignment;
uintptr_t tls_mask = tls_align - 1;
uintptr_t heap_align = _TLS_Heap_align_up( tls_align );
uintptr_t heap_mask = heap_align - 1;
TLS_Thread_control_block *tcb = (TLS_Thread_control_block *)
((char *) tls_area + ((size + heap_mask) & ~heap_mask));
void *tls_block = (char *) tcb - ((size + tls_mask) & ~tls_mask);
TLS_Dynamic_thread_vector *dtv = (TLS_Dynamic_thread_vector *)
((char *) tcb + sizeof(*tcb));
_TLS_Initialize( tls_block, tcb, dtv );
return tcb;
}
/** @} */
#ifdef __cplusplus
}
#endif /* __cplusplus */
#endif /* _RTEMS_SCORE_TLS_H */
|