/**
* @file
*
* @ingroup RTEMSScoreCPUSPARC
*
* @brief This source file contains the SPARC-specific implementation of
* _CPU_ISR_install_raw_handler() and _CPU_ISR_install_vector().
*/
/*
* COPYRIGHT (c) 1989-2007.
* On-Line Applications Research Corporation (OAR).
*
* 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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <rtems/score/isr.h>
#include <rtems/rtems/cache.h>
/*
* This initializes the set of opcodes placed in each trap
* table entry. The routine which installs a handler is responsible
* for filling in the fields for the _handler address and the _vector
* trap type.
*
* The constants following this structure are masks for the fields which
* must be filled in when the handler is installed.
*/
const CPU_Trap_table_entry _CPU_Trap_slot_template = {
0xa1480000, /* mov %psr, %l0 */
0x29000000, /* sethi %hi(_handler), %l4 */
0x81c52000, /* jmp %l4 + %lo(_handler) */
0xa6102000 /* mov _vector, %l3 */
};
/*
* _CPU_ISR_install_raw_handler
*
* This routine installs the specified handler as a "raw" non-executive
* supported trap handler (a.k.a. interrupt service routine).
*
* Input Parameters:
* vector - trap table entry number plus synchronous
* vs. asynchronous information
* new_handler - address of the handler to be installed
* old_handler - pointer to an address of the handler previously installed
*
* Output Parameters: NONE
* *new_handler - address of the handler previously installed
*
* NOTE:
*
* On the SPARC, there are really only 256 vectors. However, the executive
* has no easy, fast, reliable way to determine which traps are synchronous
* and which are asynchronous. By default, synchronous traps return to the
* instruction which caused the interrupt. So if you install a software
* trap handler as an executive interrupt handler (which is desirable since
* RTEMS takes care of window and register issues), then the executive needs
* to know that the return address is to the trap rather than the instruction
* following the trap.
*
* So vectors 0 through 255 are treated as regular asynchronous traps which
* provide the "correct" return address. Vectors 256 through 512 are assumed
* by the executive to be synchronous and to require that the return address
* be fudged.
*
* If you use this mechanism to install a trap handler which must reexecute
* the instruction which caused the trap, then it should be installed as
* an asynchronous trap. This will avoid the executive changing the return
* address.
*/
void _CPU_ISR_install_raw_handler(
uint32_t vector,
CPU_ISR_raw_handler new_handler,
CPU_ISR_raw_handler *old_handler
)
{
uint32_t real_vector;
CPU_Trap_table_entry *tbr;
CPU_Trap_table_entry *slot;
uint32_t u32_tbr;
uint32_t u32_handler;
/*
* Get the "real" trap number for this vector ignoring the synchronous
* versus asynchronous indicator included with our vector numbers.
*/
real_vector = SPARC_REAL_TRAP_NUMBER( vector );
/*
* Get the current base address of the trap table and calculate a pointer
* to the slot we are interested in.
*/
sparc_get_tbr( u32_tbr );
u32_tbr &= 0xfffff000;
tbr = (CPU_Trap_table_entry *) u32_tbr;
slot = &tbr[ real_vector ];
/*
* Get the address of the old_handler from the trap table.
*
* NOTE: The old_handler returned will be bogus if it does not follow
* the RTEMS model.
*/
#define HIGH_BITS_MASK 0xFFFFFC00
#define HIGH_BITS_SHIFT 10
#define LOW_BITS_MASK 0x000003FF
if ( slot->mov_psr_l0 == _CPU_Trap_slot_template.mov_psr_l0 ) {
u32_handler =
(slot->sethi_of_handler_to_l4 << HIGH_BITS_SHIFT) |
(slot->jmp_to_low_of_handler_plus_l4 & LOW_BITS_MASK);
*old_handler = (CPU_ISR_raw_handler) u32_handler;
} else
*old_handler = 0;
/*
* Copy the template to the slot and then fix it.
*/
*slot = _CPU_Trap_slot_template;
u32_handler = (uint32_t) new_handler;
slot->mov_vector_l3 |= vector;
slot->sethi_of_handler_to_l4 |=
(u32_handler & HIGH_BITS_MASK) >> HIGH_BITS_SHIFT;
slot->jmp_to_low_of_handler_plus_l4 |= (u32_handler & LOW_BITS_MASK);
/*
* There is no instruction cache snooping, so we need to invalidate
* the instruction cache to make sure that the processor sees the
* changes to the trap table. This step is required on both single-
* and multiprocessor systems.
*
* In a SMP configuration a change to the trap table might be
* missed by other cores. If the system state is up, the other
* cores can be notified using SMP messages that they need to
* flush their icache. If the up state has not been reached
* there is no need to notify other cores. They will do an
* automatic flush of the icache just after entering the up
* state, but before enabling interrupts.
*/
rtems_cache_invalidate_entire_instruction();
}
void _CPU_ISR_install_vector(
uint32_t vector,
CPU_ISR_handler new_handler,
CPU_ISR_handler *old_handler
)
{
uint32_t real_vector;
CPU_ISR_raw_handler ignored;
/*
* Get the "real" trap number for this vector ignoring the synchronous
* versus asynchronous indicator included with our vector numbers.
*/
real_vector = SPARC_REAL_TRAP_NUMBER( vector );
/*
* Return the previous ISR handler.
*/
*old_handler = _ISR_Vector_table[ real_vector ];
/*
* Install the wrapper so this ISR can be invoked properly.
*/
_CPU_ISR_install_raw_handler( vector, _ISR_Handler, &ignored );
/*
* We put the actual user ISR address in '_ISR_vector_table'. This will
* be used by the _ISR_Handler so the user gets control.
*/
_ISR_Vector_table[ real_vector ] = new_handler;
}
