/** * @file rtems/score/cpu.h */ /* * This include file contains macros pertaining to the Opencores * or1k processor family. * * COPYRIGHT (c) 2014 Hesham ALMatary * COPYRIGHT (c) 1989-1999. * 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. * * This file adapted from no_cpu example of the RTEMS distribution. * The body has been modified for the Opencores OR1k implementation by * Chris Ziomkowski. * */ #ifndef _OR1K_CPU_H #define _OR1K_CPU_H #ifdef __cplusplus extern "C" { #endif #include /* pick up machine definitions */ #include #include #ifndef ASM #include #include #include /* for printk */ #endif /* conditional compilation parameters */ /* * 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. * * Currently, for or1k port, _ISR_Handler is responsible for switching to * RTEMS dedicated interrupt task. * */ #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 * or CPU_INSTALL_HARDWARE_INTERRUPT_STACK is TRUE. * */ #define CPU_ALLOCATE_INTERRUPT_STACK TRUE /* * 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 TRUE /* * 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 "OR1K_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. * * The CPU_SOFTWARE_FP is used to indicate whether or not there * is software implemented floating point that must be context * switched. The determination of whether or not this applies * is very tool specific and the state saved/restored is also * compiler specific. * * Or1k Specific Information: * * At this time there are no implementations of Or1k that are * expected to implement floating point. More importantly, the * floating point architecture is expected to change significantly * before such chips are fabricated. */ #define CPU_HARDWARE_FP FALSE #define CPU_SOFTWARE_FP FALSE /* * 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. * */ #define CPU_ALL_TASKS_ARE_FP FALSE /* * 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 /* * 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. * */ #define CPU_USE_DEFERRED_FP_SWITCH TRUE #define CPU_ENABLE_ROBUST_THREAD_DISPATCH 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 TRUE /* * 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 /* FIXME: Is this the right value? */ #define CPU_CACHE_LINE_BYTES 32 #define CPU_STRUCTURE_ALIGNMENT RTEMS_ALIGNED( CPU_CACHE_LINE_BYTES ) /* * Define what is required to specify how the network to host conversion * routines are handled. * * Or1k Specific Information: * * This version of RTEMS is designed specifically to run with * big endian architectures. If you want little endian, you'll * have to make the appropriate adjustments here and write * efficient routines for byte swapping. The Or1k architecture * doesn't do this very well. */ #define CPU_HAS_OWN_HOST_TO_NETWORK_ROUTINES FALSE #define CPU_BIG_ENDIAN TRUE #define CPU_LITTLE_ENDIAN FALSE /* * The following defines the number of bits actually used in the * interrupt field of the task mode. How those bits map to the * CPU interrupt levels is defined by the routine _CPU_ISR_Set_level(). * */ #define CPU_MODES_INTERRUPT_MASK 0x00000001 /* * 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 #ifdef OR1K_64BIT_ARCH #define or1kreg uint64_t #else #define or1kreg uint32_t #endif typedef struct { uint32_t r1; /* Stack pointer */ uint32_t r2; /* Frame pointer */ uint32_t r3; uint32_t r4; uint32_t r5; uint32_t r6; uint32_t r7; uint32_t r8; uint32_t r9; uint32_t r10; uint32_t r11; uint32_t r12; uint32_t r13; uint32_t r14; uint32_t r15; uint32_t r16; uint32_t r17; uint32_t r18; uint32_t r19; uint32_t r20; uint32_t r21; uint32_t r22; uint32_t r23; uint32_t r24; uint32_t r25; uint32_t r26; uint32_t r27; uint32_t r28; uint32_t r29; uint32_t r30; uint32_t r31; uint32_t sr; /* Current supervision register non persistent values */ uint32_t epcr; uint32_t eear; uint32_t esr; } Context_Control; #define _CPU_Context_Get_SP( _context ) \ (_context)->r1 typedef struct { /** FPU registers are listed here */ double some_float_register; } Context_Control_fp; typedef Context_Control CPU_Interrupt_frame; /* * 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. * * Or1k Specific Information: * */ #define CPU_CONTEXT_FP_SIZE 0 /* * 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 /* * Should be large enough to run all RTEMS tests. This insures * that a "reasonable" small application should not have any problems. * */ #define CPU_STACK_MINIMUM_SIZE 4096 /* * 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 8 /* * This is defined if the port has a special way to report the ISR nesting * level. Most ports maintain the variable _ISR_Nest_level. */ #define CPU_PROVIDES_ISR_IS_IN_PROGRESS FALSE /** * Size of a pointer. * * This must be an integer literal that can be used by the assembler. This * value will be used to calculate offsets of structure members. These * offsets will be used in assembler code. */ #define CPU_SIZEOF_POINTER 4 /* * 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 although it should be * a multiple of 2 greater than or equal to 2. The requirement * to be a multiple of 2 is because the heap uses the least * significant field of the front and back flags to indicate * that a block is in use or free. So you do not want any odd * length blocks really putting length data in that bit. * * On byte oriented architectures, CPU_HEAP_ALIGNMENT normally will * have to be greater or equal to than CPU_ALIGNMENT to ensure that * elements allocated from the heap meet all restrictions. * */ #define CPU_HEAP_ALIGNMENT CPU_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 CPU_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 0 /* ISR handler macros */ /* * Support routine to initialize the RTEMS vector table after it is allocated. * * NO_CPU Specific Information: * * XXX document implementation including references if appropriate */ #define _CPU_Initialize_vectors() /* * Disable all interrupts for an RTEMS critical section. The previous * level is returned in _level. * */ static inline uint32_t or1k_interrupt_disable( void ) { uint32_t sr; sr = _OR1K_mfspr(CPU_OR1K_SPR_SR); _OR1K_mtspr(CPU_OR1K_SPR_SR, (sr & ~CPU_OR1K_SPR_SR_IEE)); return sr; } static inline void or1k_interrupt_enable(uint32_t level) { uint32_t sr; /* Enable interrupts and restore rs */ sr = level | CPU_OR1K_SPR_SR_IEE | CPU_OR1K_SPR_SR_TEE; _OR1K_mtspr(CPU_OR1K_SPR_SR, sr); } #define _CPU_ISR_Disable( _level ) \ _level = or1k_interrupt_disable() /* * Enable interrupts to the previous level (returned by _CPU_ISR_Disable). * This indicates the end of an RTEMS critical section. The parameter * _level is not modified. * */ #define _CPU_ISR_Enable( _level ) \ or1k_interrupt_enable( _level ) /* * This temporarily restores the interrupt to _level before immediately * disabling them again. This is used to divide long RTEMS critical * sections into two or more parts. The parameter _level is not * modified. * */ #define _CPU_ISR_Flash( _level ) \ do{ \ _CPU_ISR_Enable( _level ); \ _OR1K_mtspr(CPU_OR1K_SPR_SR, (_level & ~CPU_OR1K_SPR_SR_IEE)); \ } while(0) RTEMS_INLINE_ROUTINE bool _CPU_ISR_Is_enabled( uint32_t level ) { return ( level & CPU_OR1K_SPR_SR ) != 0; } /* * Map interrupt level in task mode onto the hardware that the CPU * actually provides. Currently, interrupt levels which do not * map onto the CPU in a generic fashion are undefined. Someday, * it would be nice if these were "mapped" by the application * via a callout. For example, m68k has 8 levels 0 - 7, levels * 8 - 255 would be available for bsp/application specific meaning. * This could be used to manage a programmable interrupt controller * via the rtems_task_mode directive. * * The get routine usually must be implemented as a subroutine. * */ void _CPU_ISR_Set_level( uint32_t level ); uint32_t _CPU_ISR_Get_level( void ); /* end of ISR handler macros */ /* Context handler macros */ #define OR1K_FAST_CONTEXT_SWITCH_ENABLED FALSE /* * 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. * * NOTE: This is_fp parameter is TRUE if the thread is to be a floating * point thread. This is typically only used on CPUs where the * FPU may be easily disabled by software such as on the SPARC * where the PSR contains an enable FPU bit. * */ /** * @brief Initializes the CPU context. * * The following steps are performed: * - setting a starting address * - preparing the stack * - preparing the stack and frame pointers * - setting the proper interrupt level in the context * * @param[in] context points to the context area * @param[in] stack_area_begin is the low address of the allocated stack area * @param[in] stack_area_size is the size of the stack area in bytes * @param[in] new_level is the interrupt level for the task * @param[in] entry_point is the task's entry point * @param[in] is_fp is set to @c true if the task is a floating point task * @param[in] tls_area is the thread-local storage (TLS) area */ void _CPU_Context_Initialize( Context_Control *context, void *stack_area_begin, size_t stack_area_size, uint32_t new_level, void (*entry_point)( void ), bool is_fp, void *tls_area ); /* * 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) ) ) #define _CPU_Context_Initialize_fp( _destination ) \ memset( *( _destination ), 0, CPU_CONTEXT_FP_SIZE ); /* end of Context handler macros */ /* 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. * */ #define _CPU_Fatal_halt(_source, _error ) \ printk("Fatal Error %d.%d Halted\n",_source, _error); \ _OR1KSIM_CPU_Halt(); \ for(;;) /* end of Fatal Error manager macros */ #define CPU_USE_GENERIC_BITFIELD_CODE TRUE #endif /* ASM */ #define CPU_SIZEOF_POINTER 4 #define CPU_MAXIMUM_PROCESSORS 32 #ifndef ASM typedef uint32_t CPU_Counter_ticks; typedef struct { uint32_t r[32]; /* The following registers must be saved if we have fast context switch disabled and nested interrupt levels are enabled. */ #if !OR1K_FAST_CONTEXT_SWITCH_ENABLED uint32_t epcr; /* exception PC register */ uint32_t eear; /* exception effective address register */ uint32_t esr; /* exception supervision register */ #endif } CPU_Exception_frame; /** * @brief Prints the exception frame via printk(). * * @see rtems_fatal() and RTEMS_FATAL_SOURCE_EXCEPTION. */ void _CPU_Exception_frame_print( const CPU_Exception_frame *frame ); /* end of Priority handler macros */ /* functions */ /* * _CPU_Initialize * * This routine performs CPU dependent initialization. * */ void _CPU_Initialize( void ); /* * _CPU_ISR_install_raw_handler * * This routine installs a "raw" interrupt handler directly into the * processor's vector table. * */ void _CPU_ISR_install_raw_handler( uint32_t vector, proc_ptr new_handler, proc_ptr *old_handler ); /* * _CPU_ISR_install_vector * * This routine installs an interrupt vector. * * NO_CPU Specific Information: * * XXX document implementation including references if appropriate */ 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_Thread_Idle_body * * This routine is the CPU dependent IDLE thread body. * * NOTE: It need only be provided if CPU_PROVIDES_IDLE_THREAD_BODY * is TRUE. * */ void *_CPU_Thread_Idle_body( uintptr_t ignored ); /* * _CPU_Context_switch * * This routine switches from the run context to the heir context. * * Or1k Specific Information: * * Please see the comments in the .c file for a description of how * this function works. There are several things to be aware of. */ void _CPU_Context_switch( Context_Control *run, Context_Control *heir ); /* * _CPU_Context_restore * * This routine is generally 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_NO_RETURN; /* * _CPU_Context_save_fp * * This routine saves the floating point context passed to it. * */ void _CPU_Context_save_fp( void **fp_context_ptr ); /* * _CPU_Context_restore_fp * * This routine restores the floating point context passed to it. * */ void _CPU_Context_restore_fp( void **fp_context_ptr ); /* 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 insure 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. * */ void _CPU_Context_volatile_clobber( uintptr_t pattern ); void _CPU_Context_validate( uintptr_t pattern ); static inline unsigned int CPU_swap_u32( unsigned int value ) { uint32_t byte1, byte2, byte3, byte4, swapped; byte4 = (value >> 24) & 0xff; byte3 = (value >> 16) & 0xff; byte2 = (value >> 8) & 0xff; byte1 = value & 0xff; swapped = (byte1 << 24) | (byte2 << 16) | (byte3 << 8) | byte4; return( swapped ); } #define CPU_swap_u16( value ) \ (((value&0xff) << 8) | ((value >> 8)&0xff)) typedef uint32_t CPU_Counter_ticks; CPU_Counter_ticks _CPU_Counter_read( void ); CPU_Counter_ticks _CPU_Counter_difference( CPU_Counter_ticks second, CPU_Counter_ticks first ); #endif /* ASM */ #ifdef __cplusplus } #endif #endif