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Diffstat (limited to 'cpukit/score/cpu/powerpc/rtems/score/cpu.h')
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diff --git a/cpukit/score/cpu/powerpc/rtems/score/cpu.h b/cpukit/score/cpu/powerpc/rtems/score/cpu.h new file mode 100644 index 0000000000..b076f7e87d --- /dev/null +++ b/cpukit/score/cpu/powerpc/rtems/score/cpu.h @@ -0,0 +1,979 @@ +/** + * @file rtems/score/cpu.h + */ + +/* + * COPYRIGHT (c) 1989-2007. + * On-Line Applications Research Corporation (OAR). + * + * COPYRIGHT (c) 1995 i-cubed ltd. + * + * To anyone who acknowledges that this file is provided "AS IS" + * without any express or implied warranty: + * permission to use, copy, modify, and distribute this file + * for any purpose is hereby granted without fee, provided that + * the above copyright notice and this notice appears in all + * copies, and that the name of i-cubed limited not be used in + * advertising or publicity pertaining to distribution of the + * software without specific, written prior permission. + * i-cubed limited makes no representations about the suitability + * of this software for any purpose. + * + * Copyright (c) 2001 Andy Dachs <a.dachs@sstl.co.uk>. + * + * Copyright (c) 2001 Surrey Satellite Technology Limited (SSTL). + * + * Copyright (c) 2010 embedded brains GmbH. + * + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * http://www.rtems.com/license/LICENSE. + * + * $Id$ + */ + +#ifndef _RTEMS_SCORE_CPU_H +#define _RTEMS_SCORE_CPU_H + +#include <rtems/score/types.h> +#include <rtems/score/powerpc.h> +#include <rtems/powerpc/registers.h> + +#ifndef ASM + #include <string.h> /* for memset() */ +#endif + +#ifdef __cplusplus +extern "C" { +#endif + +/* conditional compilation parameters */ + +/* + * Should the calls to _Thread_Enable_dispatch be inlined? + * + * If TRUE, then they are inlined. + * If FALSE, then a subroutine call is made. + * + * Basically this is an example of the classic trade-off of size + * versus speed. Inlining the call (TRUE) typically increases the + * size of RTEMS while speeding up the enabling of dispatching. + * [NOTE: In general, the _Thread_Dispatch_disable_level will + * only be 0 or 1 unless you are in an interrupt handler and that + * interrupt handler invokes the executive.] When not inlined + * something calls _Thread_Enable_dispatch which in turns calls + * _Thread_Dispatch. If the enable dispatch is inlined, then + * one subroutine call is avoided entirely.] + */ + +#define CPU_INLINE_ENABLE_DISPATCH FALSE + +/* + * Should the body of the search loops in _Thread_queue_Enqueue_priority + * be unrolled one time? In unrolled each iteration of the loop examines + * two "nodes" on the chain being searched. Otherwise, only one node + * is examined per iteration. + * + * If TRUE, then the loops are unrolled. + * If FALSE, then the loops are not unrolled. + * + * The primary factor in making this decision is the cost of disabling + * and enabling interrupts (_ISR_Flash) versus the cost of rest of the + * body of the loop. On some CPUs, the flash is more expensive than + * one iteration of the loop body. In this case, it might be desirable + * to unroll the loop. It is important to note that on some CPUs, this + * code is the longest interrupt disable period in RTEMS. So it is + * necessary to strike a balance when setting this parameter. + */ + +#define CPU_UNROLL_ENQUEUE_PRIORITY FALSE + +/* + * Does this port provide a CPU dependent IDLE task implementation? + * + * If TRUE, then the routine _CPU_Thread_Idle_body + * must be provided and is the default IDLE thread body instead of + * _CPU_Thread_Idle_body. + * + * If FALSE, then use the generic IDLE thread body if the BSP does + * not provide one. + * + * This is intended to allow for supporting processors which have + * a low power or idle mode. When the IDLE thread is executed, then + * the CPU can be powered down. + * + * The order of precedence for selecting the IDLE thread body is: + * + * 1. BSP provided + * 2. CPU dependent (if provided) + * 3. generic (if no BSP and no CPU dependent) + */ + +#define CPU_PROVIDES_IDLE_THREAD_BODY FALSE + +/* + * Does the stack grow up (toward higher addresses) or down + * (toward lower addresses)? + * + * If TRUE, then the grows upward. + * If FALSE, then the grows toward smaller addresses. + */ + +#define CPU_STACK_GROWS_UP FALSE + +/* + * The following is the variable attribute used to force alignment + * of critical RTEMS structures. On some processors it may make + * sense to have these aligned on tighter boundaries than + * the minimum requirements of the compiler in order to have as + * much of the critical data area as possible in a cache line. + * + * The placement of this macro in the declaration of the variables + * is based on the syntactically requirements of the GNU C + * "__attribute__" extension. For example with GNU C, use + * the following to force a structures to a 32 byte boundary. + * + * __attribute__ ((aligned (32))) + * + * NOTE: Currently only the Priority Bit Map table uses this feature. + * To benefit from using this, the data must be heavily + * used so it will stay in the cache and used frequently enough + * in the executive to justify turning this on. + */ + +#define CPU_STRUCTURE_ALIGNMENT \ + __attribute__ ((aligned (PPC_STRUCTURE_ALIGNMENT))) + +/* + * Define what is required to specify how the network to host conversion + * routines are handled. + */ + +#if defined(__BIG_ENDIAN__) || defined(_BIG_ENDIAN) +#define CPU_BIG_ENDIAN TRUE +#define CPU_LITTLE_ENDIAN FALSE +#else +#define CPU_BIG_ENDIAN FALSE +#define CPU_LITTLE_ENDIAN TRUE +#endif + +/* + * Does the CPU have hardware floating point? + * + * If TRUE, then the RTEMS_FLOATING_POINT task attribute is supported. + * If FALSE, then the RTEMS_FLOATING_POINT task attribute is ignored. + * + * If there is a FP coprocessor such as the i387 or mc68881, then + * the answer is TRUE. + * + * The macro name "PPC_HAS_FPU" should be made CPU specific. + * It indicates whether or not this CPU model has FP support. For + * example, it would be possible to have an i386_nofp CPU model + * which set this to false to indicate that you have an i386 without + * an i387 and wish to leave floating point support out of RTEMS. + */ + +#if ( PPC_HAS_FPU == 1 ) +#define CPU_HARDWARE_FP TRUE +#define CPU_SOFTWARE_FP FALSE +#else +#define CPU_HARDWARE_FP FALSE +#define CPU_SOFTWARE_FP FALSE +#endif + +/* + * Are all tasks RTEMS_FLOATING_POINT tasks implicitly? + * + * If TRUE, then the RTEMS_FLOATING_POINT task attribute is assumed. + * If FALSE, then the RTEMS_FLOATING_POINT task attribute is followed. + * + * If CPU_HARDWARE_FP is FALSE, then this should be FALSE as well. + * + * PowerPC Note: It appears the GCC can implicitly generate FPU + * and Altivec instructions when you least expect them. So make + * all tasks floating point. + */ + +#define CPU_ALL_TASKS_ARE_FP CPU_HARDWARE_FP + +/* + * Should the IDLE task have a floating point context? + * + * If TRUE, then the IDLE task is created as a RTEMS_FLOATING_POINT task + * and it has a floating point context which is switched in and out. + * If FALSE, then the IDLE task does not have a floating point context. + * + * Setting this to TRUE negatively impacts the time required to preempt + * the IDLE task from an interrupt because the floating point context + * must be saved as part of the preemption. + */ + +#define CPU_IDLE_TASK_IS_FP FALSE + +/* + * Processor defined structures required for cpukit/score. + */ + +/* + * Contexts + * + * Generally there are 2 types of context to save. + * 1. Interrupt registers to save + * 2. Task level registers to save + * + * This means we have the following 3 context items: + * 1. task level context stuff:: Context_Control + * 2. floating point task stuff:: Context_Control_fp + * 3. special interrupt level context :: Context_Control_interrupt + * + * On some processors, it is cost-effective to save only the callee + * preserved registers during a task context switch. This means + * that the ISR code needs to save those registers which do not + * persist across function calls. It is not mandatory to make this + * distinctions between the caller/callee saves registers for the + * purpose of minimizing context saved during task switch and on interrupts. + * If the cost of saving extra registers is minimal, simplicity is the + * choice. Save the same context on interrupt entry as for tasks in + * this case. + * + * Additionally, if gdb is to be made aware of RTEMS tasks for this CPU, then + * care should be used in designing the context area. + * + * On some CPUs with hardware floating point support, the Context_Control_fp + * structure will not be used or it simply consist of an array of a + * fixed number of bytes. This is done when the floating point context + * is dumped by a "FP save context" type instruction and the format + * is not really defined by the CPU. In this case, there is no need + * to figure out the exact format -- only the size. Of course, although + * this is enough information for RTEMS, it is probably not enough for + * a debugger such as gdb. But that is another problem. + */ + +#ifndef ASM + +typedef struct { + uint32_t gpr1; /* Stack pointer for all */ + uint32_t gpr2; /* Reserved SVR4, section ptr EABI + */ + uint32_t gpr13; /* Section ptr SVR4/EABI */ + uint32_t gpr14; /* Non volatile for all */ + uint32_t gpr15; /* Non volatile for all */ + uint32_t gpr16; /* Non volatile for all */ + uint32_t gpr17; /* Non volatile for all */ + uint32_t gpr18; /* Non volatile for all */ + uint32_t gpr19; /* Non volatile for all */ + uint32_t gpr20; /* Non volatile for all */ + uint32_t gpr21; /* Non volatile for all */ + uint32_t gpr22; /* Non volatile for all */ + uint32_t gpr23; /* Non volatile for all */ + uint32_t gpr24; /* Non volatile for all */ + uint32_t gpr25; /* Non volatile for all */ + uint32_t gpr26; /* Non volatile for all */ + uint32_t gpr27; /* Non volatile for all */ + uint32_t gpr28; /* Non volatile for all */ + uint32_t gpr29; /* Non volatile for all */ + uint32_t gpr30; /* Non volatile for all */ + uint32_t gpr31; /* Non volatile for all */ + uint32_t cr; /* PART of the CR is non volatile for all */ + uint32_t pc; /* Program counter/Link register */ + uint32_t msr; /* Initial interrupt level */ +#ifdef __ALTIVEC__ + /* 12 non-volatile vector registers, cache-aligned area for vscr/vrsave + * and padding to ensure cache-alignment. + * Unfortunately, we can't verify the cache line size here + * in the cpukit but altivec support code will produce an + * error if this is ever different from 32 bytes. + * + * Note: it is the BSP/CPU-support's responsibility to + * save/restore volatile vregs across interrupts + * and exceptions. + */ + uint8_t altivec[16*12 + 32 + 32]; +#endif +} Context_Control; + +#define _CPU_Context_Get_SP( _context ) \ + (_context)->gpr1 + +typedef struct { + /* The ABIs (PowerOpen/SVR4/EABI) only require saving f14-f31 over + * procedure calls. However, this would mean that the interrupt + * frame had to hold f0-f13, and the fpscr. And as the majority + * of tasks will not have an FP context, we will save the whole + * context here. + */ +#if (PPC_HAS_DOUBLE == 1) + double f[32]; + uint64_t fpscr; +#else + float f[32]; + uint32_t fpscr; +#endif +} Context_Control_fp; + +typedef struct CPU_Interrupt_frame { + uint32_t stacklink; /* Ensure this is a real frame (also reg1 save) */ + uint32_t calleeLr; /* link register used by callees: SVR4/EABI */ + + /* This is what is left out of the primary contexts */ + uint32_t gpr0; + uint32_t gpr2; /* play safe */ + uint32_t gpr3; + uint32_t gpr4; + uint32_t gpr5; + uint32_t gpr6; + uint32_t gpr7; + uint32_t gpr8; + uint32_t gpr9; + uint32_t gpr10; + uint32_t gpr11; + uint32_t gpr12; + uint32_t gpr13; /* Play safe */ + uint32_t gpr28; /* For internal use by the IRQ handler */ + uint32_t gpr29; /* For internal use by the IRQ handler */ + uint32_t gpr30; /* For internal use by the IRQ handler */ + uint32_t gpr31; /* For internal use by the IRQ handler */ + uint32_t cr; /* Bits of this are volatile, so no-one may save */ + uint32_t ctr; + uint32_t xer; + uint32_t lr; + uint32_t pc; + uint32_t msr; + uint32_t pad[3]; +} CPU_Interrupt_frame; + +#endif /* ASM */ + +/* + * Does RTEMS manage a dedicated interrupt stack in software? + * + * If TRUE, then a stack is allocated in _ISR_Handler_initialization. + * If FALSE, nothing is done. + * + * If the CPU supports a dedicated interrupt stack in hardware, + * then it is generally the responsibility of the BSP to allocate it + * and set it up. + * + * If the CPU does not support a dedicated interrupt stack, then + * the porter has two options: (1) execute interrupts on the + * stack of the interrupted task, and (2) have RTEMS manage a dedicated + * interrupt stack. + * + * If this is TRUE, CPU_ALLOCATE_INTERRUPT_STACK should also be TRUE. + * + * Only one of CPU_HAS_SOFTWARE_INTERRUPT_STACK and + * CPU_HAS_HARDWARE_INTERRUPT_STACK should be set to TRUE. It is + * possible that both are FALSE for a particular CPU. Although it + * is unclear what that would imply about the interrupt processing + * procedure on that CPU. + */ + +#define CPU_HAS_SOFTWARE_INTERRUPT_STACK TRUE + +/* + * Does this CPU have hardware support for a dedicated interrupt stack? + * + * If TRUE, then it must be installed during initialization. + * If FALSE, then no installation is performed. + * + * If this is TRUE, CPU_ALLOCATE_INTERRUPT_STACK should also be TRUE. + * + * Only one of CPU_HAS_SOFTWARE_INTERRUPT_STACK and + * CPU_HAS_HARDWARE_INTERRUPT_STACK should be set to TRUE. It is + * possible that both are FALSE for a particular CPU. Although it + * is unclear what that would imply about the interrupt processing + * procedure on that CPU. + */ + +#define CPU_HAS_HARDWARE_INTERRUPT_STACK FALSE + +/* + * Does RTEMS allocate a dedicated interrupt stack in the Interrupt Manager? + * + * If TRUE, then the memory is allocated during initialization. + * If FALSE, then the memory is allocated during initialization. + * + * This should be TRUE is CPU_HAS_SOFTWARE_INTERRUPT_STACK is TRUE. + */ + +#define CPU_ALLOCATE_INTERRUPT_STACK FALSE + +/* + * Does the RTEMS invoke the user's ISR with the vector number and + * a pointer to the saved interrupt frame (1) or just the vector + * number (0)? + */ + +#define CPU_ISR_PASSES_FRAME_POINTER 0 + +/* + * Should the saving of the floating point registers be deferred + * until a context switch is made to another different floating point + * task? + * + * If TRUE, then the floating point context will not be stored until + * necessary. It will remain in the floating point registers and not + * disturned until another floating point task is switched to. + * + * If FALSE, then the floating point context is saved when a floating + * point task is switched out and restored when the next floating point + * task is restored. The state of the floating point registers between + * those two operations is not specified. + * + * If the floating point context does NOT have to be saved as part of + * interrupt dispatching, then it should be safe to set this to TRUE. + * + * Setting this flag to TRUE results in using a different algorithm + * for deciding when to save and restore the floating point context. + * The deferred FP switch algorithm minimizes the number of times + * the FP context is saved and restored. The FP context is not saved + * until a context switch is made to another, different FP task. + * Thus in a system with only one FP task, the FP context will never + * be saved or restored. + * + * Note, however that compilers may use floating point registers/ + * instructions for optimization or they may save/restore FP registers + * on the stack. You must not use deferred switching in these cases + * and on the PowerPC attempting to do so will raise a "FP unavailable" + * exception. + */ +/* + * ACB Note: This could make debugging tricky.. + */ + +/* conservative setting (FALSE); probably doesn't affect performance too much */ +#define CPU_USE_DEFERRED_FP_SWITCH FALSE + +/* + * Processor defined structures required for cpukit/score. + */ + +#ifndef ASM + +/* + * This variable is optional. It is used on CPUs on which it is difficult + * to generate an "uninitialized" FP context. It is filled in by + * _CPU_Initialize and copied into the task's FP context area during + * _CPU_Context_Initialize. + */ + +/* EXTERN Context_Control_fp _CPU_Null_fp_context; */ + +#endif /* ndef ASM */ + +/* + * This defines the number of levels and the mask used to pick those + * bits out of a thread mode. + */ + +#define CPU_MODES_INTERRUPT_LEVEL 0x00000001 /* interrupt level in mode */ +#define CPU_MODES_INTERRUPT_MASK 0x00000001 /* interrupt level in mode */ + +/* + * Nothing prevents the porter from declaring more CPU specific variables. + */ + +#ifndef ASM + +SCORE_EXTERN struct { + uint32_t *Disable_level; + void *Stack; + volatile bool *Switch_necessary; + bool *Signal; + +} _CPU_IRQ_info CPU_STRUCTURE_ALIGNMENT; + +#endif /* ndef ASM */ + +/* + * The size of the floating point context area. On some CPUs this + * will not be a "sizeof" because the format of the floating point + * area is not defined -- only the size is. This is usually on + * CPUs with a "floating point save context" instruction. + */ + +#define CPU_CONTEXT_FP_SIZE sizeof( Context_Control_fp ) + +/* + * (Optional) # of bytes for libmisc/stackchk to check + * If not specifed, then it defaults to something reasonable + * for most architectures. + */ + +#define CPU_STACK_CHECK_SIZE (128) + +/* + * Amount of extra stack (above minimum stack size) required by + * MPCI receive server thread. Remember that in a multiprocessor + * system this thread must exist and be able to process all directives. + */ + +#define CPU_MPCI_RECEIVE_SERVER_EXTRA_STACK 0 + +/* + * This defines the number of entries in the ISR_Vector_table managed + * by RTEMS. + */ + +#define CPU_INTERRUPT_NUMBER_OF_VECTORS (0) +#define CPU_INTERRUPT_MAXIMUM_VECTOR_NUMBER (UINT32_MAX) + +/* + * This is defined if the port has a special way to report the ISR nesting + * level. Most ports maintain the variable _ISR_Nest_level. Note that + * this is not an option - RTEMS/score _relies_ on _ISR_Nest_level + * being maintained (e.g. watchdog queues). + */ + +#define CPU_PROVIDES_ISR_IS_IN_PROGRESS FALSE + +/* + * ISR handler macros + */ + +#define _CPU_Initialize_vectors() + +/* + * Disable all interrupts for an RTEMS critical section. The previous + * level is returned in _isr_cookie. + */ + +#ifndef ASM + +static inline uint32_t _CPU_ISR_Get_level( void ) +{ + register unsigned int msr; + _CPU_MSR_GET(msr); + if (msr & MSR_EE) return 0; + else return 1; +} + +static inline void _CPU_ISR_Set_level( uint32_t level ) +{ + register unsigned int msr; + _CPU_MSR_GET(msr); + if (!(level & CPU_MODES_INTERRUPT_MASK)) { + msr |= ppc_interrupt_get_disable_mask(); + } + else { + msr &= ~ppc_interrupt_get_disable_mask(); + } + _CPU_MSR_SET(msr); +} + +void BSP_panic(char *); + +/* Fatal Error manager macros */ + +/* + * This routine copies _error into a known place -- typically a stack + * location or a register, optionally disables interrupts, and + * halts/stops the CPU. + */ + +void _BSP_Fatal_error(unsigned int); + +#endif /* ASM */ + +#define _CPU_Fatal_halt( _error ) \ + _BSP_Fatal_error(_error) + +/* end of Fatal Error manager macros */ + +/* + * SPRG0 was previously used to make sure that the BSP fixed the PR288 bug. + * Now SPRG0 is devoted to the interrupt disable mask. + */ + +#define PPC_BSP_HAS_FIXED_PR288 ppc_this_is_now_the_interrupt_disable_mask + +/* + * Should be large enough to run all RTEMS tests. This ensures + * that a "reasonable" small application should not have any problems. + */ + +#define CPU_STACK_MINIMUM_SIZE (1024*8) + +/* + * CPU's worst alignment requirement for data types on a byte boundary. This + * alignment does not take into account the requirements for the stack. + */ + +#define CPU_ALIGNMENT (PPC_ALIGNMENT) + +/* + * This number corresponds to the byte alignment requirement for the + * heap handler. This alignment requirement may be stricter than that + * for the data types alignment specified by CPU_ALIGNMENT. It is + * common for the heap to follow the same alignment requirement as + * CPU_ALIGNMENT. If the CPU_ALIGNMENT is strict enough for the heap, + * then this should be set to CPU_ALIGNMENT. + * + * NOTE: This does not have to be a power of 2. It does have to + * be greater or equal to than CPU_ALIGNMENT. + */ + +#define CPU_HEAP_ALIGNMENT (PPC_ALIGNMENT) + +/* + * This number corresponds to the byte alignment requirement for memory + * buffers allocated by the partition manager. This alignment requirement + * may be stricter than that for the data types alignment specified by + * CPU_ALIGNMENT. It is common for the partition to follow the same + * alignment requirement as CPU_ALIGNMENT. If the CPU_ALIGNMENT is strict + * enough for the partition, then this should be set to CPU_ALIGNMENT. + * + * NOTE: This does not have to be a power of 2. It does have to + * be greater or equal to than CPU_ALIGNMENT. + */ + +#define CPU_PARTITION_ALIGNMENT (PPC_ALIGNMENT) + +/* + * This number corresponds to the byte alignment requirement for the + * stack. This alignment requirement may be stricter than that for the + * data types alignment specified by CPU_ALIGNMENT. If the CPU_ALIGNMENT + * is strict enough for the stack, then this should be set to 0. + * + * NOTE: This must be a power of 2 either 0 or greater than CPU_ALIGNMENT. + */ + +#define CPU_STACK_ALIGNMENT (PPC_STACK_ALIGNMENT) + +#ifndef ASM +/* The following routine swaps the endian format of an unsigned int. + * It must be static because it is referenced indirectly. + * + * This version will work on any processor, but if there is a better + * way for your CPU PLEASE use it. The most common way to do this is to: + * + * swap least significant two bytes with 16-bit rotate + * swap upper and lower 16-bits + * swap most significant two bytes with 16-bit rotate + * + * Some CPUs have special instructions which swap a 32-bit quantity in + * a single instruction (e.g. i486). It is probably best to avoid + * an "endian swapping control bit" in the CPU. One good reason is + * that interrupts would probably have to be disabled to ensure that + * an interrupt does not try to access the same "chunk" with the wrong + * endian. Another good reason is that on some CPUs, the endian bit + * endianness for ALL fetches -- both code and data -- so the code + * will be fetched incorrectly. + */ + +static inline uint32_t CPU_swap_u32( + uint32_t value +) +{ + uint32_t swapped; + + __asm__ volatile("rlwimi %0,%1,8,24,31;" + "rlwimi %0,%1,24,16,23;" + "rlwimi %0,%1,8,8,15;" + "rlwimi %0,%1,24,0,7;" : + "=&r" ((swapped)) : "r" ((value))); + + return( swapped ); +} + +#define CPU_swap_u16( value ) \ + (((value&0xff) << 8) | ((value >> 8)&0xff)) + +#endif /* ASM */ + + +#ifndef ASM +/* Context handler macros */ + +/* + * Initialize the context to a state suitable for starting a + * task after a context restore operation. Generally, this + * involves: + * + * - setting a starting address + * - preparing the stack + * - preparing the stack and frame pointers + * - setting the proper interrupt level in the context + * - initializing the floating point context + * + * This routine generally does not set any unnecessary register + * in the context. The state of the "general data" registers is + * undefined at task start time. + */ + +void _CPU_Context_Initialize( + Context_Control *the_context, + uint32_t *stack_base, + uint32_t size, + uint32_t new_level, + void *entry_point, + bool is_fp +); + +/* + * This routine is responsible for somehow restarting the currently + * executing task. If you are lucky, then all that is necessary + * is restoring the context. Otherwise, there will need to be + * a special assembly routine which does something special in this + * case. Context_Restore should work most of the time. It will + * not work if restarting self conflicts with the stack frame + * assumptions of restoring a context. + */ + +#define _CPU_Context_Restart_self( _the_context ) \ + _CPU_Context_restore( (_the_context) ); + +/* + * The purpose of this macro is to allow the initial pointer into + * a floating point context area (used to save the floating point + * context) to be at an arbitrary place in the floating point + * context area. + * + * This is necessary because some FP units are designed to have + * their context saved as a stack which grows into lower addresses. + * Other FP units can be saved by simply moving registers into offsets + * from the base of the context area. Finally some FP units provide + * a "dump context" instruction which could fill in from high to low + * or low to high based on the whim of the CPU designers. + */ + +#define _CPU_Context_Fp_start( _base, _offset ) \ + ( (void *) _Addresses_Add_offset( (_base), (_offset) ) ) + +/* + * This routine initializes the FP context area passed to it to. + * There are a few standard ways in which to initialize the + * floating point context. The code included for this macro assumes + * that this is a CPU in which a "initial" FP context was saved into + * _CPU_Null_fp_context and it simply copies it to the destination + * context passed to it. + * + * Other models include (1) not doing anything, and (2) putting + * a "null FP status word" in the correct place in the FP context. + */ + +#define _CPU_Context_Initialize_fp( _destination ) \ + memset( *(_destination), 0, sizeof( **(_destination) ) ) + +/* end of Context handler macros */ +#endif /* ASM */ + +#ifndef ASM +/* 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 */ +#endif /* ASM */ + +/* functions */ + +#ifndef ASM + +/* + * _CPU_Initialize + * + * This routine performs CPU dependent initialization. + */ + +void _CPU_Initialize(void); + +/* + * _CPU_ISR_install_vector + * + * This routine installs an interrupt vector. + */ + +void _CPU_ISR_install_vector( + uint32_t vector, + proc_ptr new_handler, + proc_ptr *old_handler +); + +/* + * _CPU_Install_interrupt_stack + * + * This routine installs the hardware interrupt stack pointer. + * + * NOTE: It need only be provided if CPU_HAS_HARDWARE_INTERRUPT_STACK + * is TRUE. + */ + +void _CPU_Install_interrupt_stack( void ); + +/* + * _CPU_Context_switch + * + * This routine switches from the run context to the heir context. + */ + +void _CPU_Context_switch( + Context_Control *run, + Context_Control *heir +); + +/* + * _CPU_Context_restore + * + * This routine is generallu used only to restart self in an + * efficient manner. It may simply be a label in _CPU_Context_switch. + * + * NOTE: May be unnecessary to reload some registers. + */ + +void _CPU_Context_restore( + Context_Control *new_context +) RTEMS_COMPILER_NO_RETURN_ATTRIBUTE; + +/* + * _CPU_Context_save_fp + * + * This routine saves the floating point context passed to it. + */ + +void _CPU_Context_save_fp( + Context_Control_fp **fp_context_ptr +); + +/* + * _CPU_Context_restore_fp + * + * This routine restores the floating point context passed to it. + */ + +void _CPU_Context_restore_fp( + Context_Control_fp **fp_context_ptr +); + +/* + * _CPU_Initialize_altivec() + * + * Global altivec-related initialization. + */ +void +_CPU_Initialize_altivec(void); + +/* + * _CPU_Context_switch_altivec + * + * This routine switches the altivec contexts passed to it. + */ + +void +_CPU_Context_switch_altivec( + Context_Control *from, + Context_Control *to +); + +/* + * _CPU_Context_restore_altivec + * + * This routine restores the altivec context passed to it. + */ + +void +_CPU_Context_restore_altivec( + Context_Control *ctxt +); + +/* + * _CPU_Context_initialize_altivec + * + * This routine initializes the altivec context passed to it. + */ + +void +_CPU_Context_initialize_altivec( + Context_Control *ctxt +); + +void _CPU_Fatal_error( + uint32_t _error +); + +#endif /* ASM */ + +#ifdef __cplusplus +} +#endif + +#endif /* _RTEMS_SCORE_CPU_H */ |