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/* Copyright 2018 SiFive, Inc */
/* SPDX-License-Identifier: Apache-2.0 */
/*! @file cpu.h
* @brief API for accessing CPU capabilities.
*/
#ifndef METAL__CPU_H
#define METAL__CPU_H
#include <stdint.h>
#include <metal/interrupt.h>
struct metal_cpu;
/*!
* @brief Function signature for exception handlers
*/
typedef void (*metal_exception_handler_t) (struct metal_cpu *cpu, int ecode);
struct metal_cpu_vtable {
unsigned long long (*mcycle_get)(struct metal_cpu *cpu);
unsigned long long (*timebase_get)(struct metal_cpu *cpu);
unsigned long long (*mtime_get)(struct metal_cpu *cpu);
int (*mtimecmp_set)(struct metal_cpu *cpu, unsigned long long time);
struct metal_interrupt* (*tmr_controller_interrupt)(struct metal_cpu *cpu);
int (*get_tmr_interrupt_id)(struct metal_cpu *cpu);
struct metal_interrupt* (*sw_controller_interrupt)(struct metal_cpu *cpu);
int (*get_sw_interrupt_id)(struct metal_cpu *cpu);
int (*set_sw_ipi)(struct metal_cpu *cpu, int hartid);
int (*clear_sw_ipi)(struct metal_cpu *cpu, int hartid);
int (*get_msip)(struct metal_cpu *cpu, int hartid);
struct metal_interrupt* (*controller_interrupt)(struct metal_cpu *cpu);
int (*exception_register)(struct metal_cpu *cpu, int ecode, metal_exception_handler_t handler);
int (*get_ilen)(struct metal_cpu *cpu, uintptr_t epc);
uintptr_t (*get_epc)(struct metal_cpu *cpu);
int (*set_epc)(struct metal_cpu *cpu, uintptr_t epc);
};
/*! @brief A device handle for a CPU hart
*/
struct metal_cpu {
const struct metal_cpu_vtable *vtable;
};
/*! @brief Get a reference to a CPU hart
*
* @param hartid The ID of the desired CPU hart
* @return A pointer to the CPU device handle
*/
struct metal_cpu* metal_cpu_get(unsigned int hartid);
/*! @brief Get the hartid of the CPU hart executing this function
*
* @return The hartid of the current CPU hart */
int metal_cpu_get_current_hartid(void);
/*! @brief Get the number of CPU harts
*
* @return The number of CPU harts */
int metal_cpu_get_num_harts(void);
/*! @brief Get the CPU cycle count timer value
*
* Get the value of the cycle count timer for a given CPU
*
* @param cpu The CPU device handle
* @return The value of the CPU cycle count timer
*/
__inline__ unsigned long long metal_cpu_get_timer(struct metal_cpu *cpu)
{ return cpu->vtable->mcycle_get(cpu); }
/*! @brief Get the timebase of the CPU
*
* Get the value of the timebase of the cycle count timer
*
* @param cpu The CPU device handle
* @return The value of the cycle count timer timebase
*/
__inline__ unsigned long long metal_cpu_get_timebase(struct metal_cpu *cpu)
{ return cpu->vtable->timebase_get(cpu); }
/*! @brief Get the value of the mtime RTC
*
* Get the value of the mtime real-time clock. The CPU interrupt controller
* must be initialized before this function is called or the return value
* will be 0.
*
* @param cpu The CPU device handle
* @return The value of mtime, or 0 if failure
*/
__inline__ unsigned long long metal_cpu_get_mtime(struct metal_cpu *cpu)
{ return cpu->vtable->mtime_get(cpu); }
/*! @brief Set the value of the RTC mtimecmp RTC
*
* Set the value of the mtime real-time clock compare register. The CPU
* interrupt controller must be initialized before this function is called
* or the return value will be -1;
*
* @param cpu The CPU device handle
* @param time The value to set the compare register to
* @return The value of mtimecmp or -1 if error
*/
__inline__ int metal_cpu_set_mtimecmp(struct metal_cpu *cpu, unsigned long long time)
{ return cpu->vtable->mtimecmp_set(cpu, time); }
/*! @brief Get a reference to RTC timer interrupt controller
*
* Get a reference to the interrupt controller for the real-time clock interrupt.
* The controller returned by this function must be initialized before any interrupts
* are registered or enabled with it.
*
* @param cpu The CPU device handle
* @return A pointer to the timer interrupt handle
*/
__inline__ struct metal_interrupt* metal_cpu_timer_interrupt_controller(struct metal_cpu *cpu)
{ return cpu->vtable->tmr_controller_interrupt(cpu); }
/*! @brief Get the RTC timer interrupt id
*
* Get the interrupt ID of the real-time clock interrupt
*
* @param cpu The CPU device handle
* @return The timer interrupt ID
*/
__inline__ int metal_cpu_timer_get_interrupt_id(struct metal_cpu *cpu)
{ return cpu->vtable->get_tmr_interrupt_id(cpu); }
/*! @brief Get a reference to the software interrupt controller
*
* Get a reference to the interrupt controller for the software/inter-process
* interrupt. The controller returned by this function must be initialized before
* any interrupts are registered or enabled with it.
*
* @param cpu The CPU device handle
* @return A pointer to the software interrupt handle
*/
__inline__ struct metal_interrupt* metal_cpu_software_interrupt_controller(struct metal_cpu *cpu)
{ return cpu->vtable->sw_controller_interrupt(cpu); }
/*! @brief Get the software interrupt id
*
* Get the interrupt ID for the software/inter-process interrupt
*
* @param cpu The CPU device handle
* @return the software interrupt ID
*/
__inline__ int metal_cpu_software_get_interrupt_id(struct metal_cpu *cpu)
{ return cpu->vtable->get_sw_interrupt_id(cpu); }
/*!
* @brief Set the inter-process interrupt for a hart
*
* Trigger a software/inter-process interrupt for a hart. The CPU interrupt
* controller for the CPU handle passed to this function must be initialized
* before this function is called.
*
* @param cpu The CPU device handle
* @param hartid The CPU hart ID to be interrupted
* @return 0 upon success
*/
__inline__ int metal_cpu_software_set_ipi(struct metal_cpu *cpu, int hartid)
{ return cpu->vtable->set_sw_ipi(cpu, hartid); }
/*!
* @brief Clear the inter-process interrupt for a hart
*
* Clear the software/inter-process interrupt for a hart. The CPU interrupt
* controller for the CPU handle passed to this function must be initialized
* before this function is called.
*
* @param cpu The CPU device handle
* @param hartid The CPU hart ID to clear
* @return 0 upon success
*/
__inline__ int metal_cpu_software_clear_ipi(struct metal_cpu *cpu, int hartid)
{ return cpu->vtable->clear_sw_ipi(cpu, hartid); }
/*!
* @brief Get the value of MSIP for the given hart
*
* Get the value of the machine software interrupt pending bit for
* the given hart. The CPU interrupt controller for the CPU handle passed
* as argument to this function must be initialized before this function
* is called.
*
* @param cpu the CPU device handle
* @param hartid The CPU hart to read
* @return 0 upon success
*/
__inline__ int metal_cpu_get_msip(struct metal_cpu *cpu, int hartid)
{ return cpu->vtable->get_msip(cpu, hartid); }
/*!
* @brief Get the interrupt controller for the CPU
*
* Get the CPU interrupt controller. The controller returned by this
* function must be initialized before any interrupts are registered
* or enabled and before any exception handlers are registered with
* this CPU.
*
* @param cpu The CPU device handle
* @return The handle for the CPU interrupt controller
*/
__inline__ struct metal_interrupt* metal_cpu_interrupt_controller(struct metal_cpu *cpu)
{ return cpu->vtable->controller_interrupt(cpu); }
/*!
* @brief Register an exception handler
*
* Register an exception handler for the CPU. The CPU interrupt controller must be initialized
* before this function is called.
*
* @param cpu The CPU device handle
* @param ecode The exception code to register a handler for
* @param handler Callback function for the exception handler
* @return 0 upon success
*/
__inline__ int metal_cpu_exception_register(struct metal_cpu *cpu, int ecode, metal_exception_handler_t handler)
{ return cpu->vtable->exception_register(cpu, ecode, handler); }
/*!
* @brief Get the length of an instruction in bytes
*
* Get the length of an instruction in bytes.
*
* On RISC-V platforms, this is useful for detecting whether an instruction is
* compressed (2 bytes long) or uncompressed (4 bytes long).
*
* This function is useful in conjuction with `metal_cpu_get_exception_pc()`
* and `metal_cpu_set_exception_pc()` in order to cause the exception handler to
* return execution after the faulting instruction.
*
* @param cpu The CPU device handle
* @param epc The address of the instruction to measure
* @return the length of the instruction in bytes
*/
__inline__ int metal_cpu_get_instruction_length(struct metal_cpu *cpu, uintptr_t epc)
{ return cpu->vtable->get_ilen(cpu, epc); }
/*!
* @brief Get the program counter of the current exception.
*
* This function must be called within an exception handler. The behavior is
* undefined outside of an exception handler.
*
* @param cpu The CPU device handle
* @return The value of the program counter at the time of the exception
*/
__inline__ uintptr_t metal_cpu_get_exception_pc(struct metal_cpu *cpu)
{ return cpu->vtable->get_epc(cpu); }
/*!
* @brief Set the exception program counter
*
* This function must be called within an exception handler. The behavior
* is undefined outside of an exception handler.
*
* This function can be used to cause an exception handler to return execution
* to an address other than the one that caused the exception.
*
* @param cpu the CPU device handle
* @param epc The address to set the exception program counter to
* @return 0 upon success
*/
__inline__ int metal_cpu_set_exception_pc(struct metal_cpu *cpu, uintptr_t epc)
{ return cpu->vtable->set_epc(cpu, epc); }
#endif
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