riscvreg.h

// Copyright Microsoft and CHERIoT Contributors.
// SPDX-License-Identifier: MIT
 
#pragma once
 
#include <stdint.h>
 
#define GR_READ(name)                                                          \
    ({                                                                         \
        size_t val;                                                            \
        __asm __volatile("mv %0, " #name : "=r"(val));                         \
        val;                                                                   \
    })
 
#define GR_WRITE(name, val)                                                    \
    ({ __asm __volatile("mv " #name ", %0" ::"r"(val)); })
 
#define CSR_READ64(csr)                                                        \
    ({                                                                         \
        uint64_t val;                                                          \
        uint32_t high, low;                                                    \
        __asm __volatile("1: "                                                 \
                         "csrr t0, " #csr "h\n"                                \
                         "csrr %0, " #csr "\n"                                 \
                         "csrr %1, " #csr "h\n"                                \
                         "bne t0, %1, 1b"                                      \
                         : "=r"(low), "=r"(high)                               \
                         :                                                     \
                         : "t0");                                              \
        val = (low | ((uint64_t)high << 32));                                  \
        val;                                                                   \
    })
 
// This hack reads the absolute integer address of a symbol.
#define LA_ABS(symbol)                                                         \
    ({                                                                         \
        size_t val;                                                            \
        __asm __volatile("lui %0, %%hi(" #symbol ")\n"                         \
                         "addi %0, %0, %%lo(" #symbol ")"                      \
                         : "=r"(val));                                         \
        val;                                                                   \
    })
 
#define BARRIER() __asm volatile("" : : : "memory")
 
/**
 * Read the cycle counter.  Returns the number of cycles since boot as a 64-bit
 * value.
 */
static inline uint64_t rdcycle64()
{
    return CSR_READ64(mcycle);
}