sbi.c

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/* SPDX-License-Identifier: GPL-2.0-only */
 
#include <mcall.h>
#include <stdint.h>
#include <arch/exception.h>
#include <sbi.h>
#include <vm.h>
#include <console/uart.h>
#include <commonlib/helpers.h>
 
static uintptr_t send_ipi(uintptr_t *pmask, intptr_t type)
{
        uintptr_t mask = mprv_read_uintptr_t(pmask);
        for (int i = 0; mask; i++) {
                if (mask & 1) {
                        OTHER_HLS(i)->ipi_pending |= type;
                        /* send soft interrupt to target hart */
                        set_msip(i, 1);
                }
                mask = mask >> 1;
        }
        return 0;
}
 
static uintptr_t sbi_set_timer(uint64_t when)
{
        clear_csr(mip, MIP_STIP);
        set_csr(mie, MIP_MTIP);
        *(HLS()->timecmp) = when;
        return 0;
}
 
#if CONFIG(CONSOLE_SERIAL)
static uintptr_t sbi_console_putchar(uint8_t ch)
{
        uart_tx_byte(CONFIG_UART_FOR_CONSOLE, ch);
        return 0;
}
 
static uintptr_t sbi_console_getchar(void)
{
        return uart_rx_byte(CONFIG_UART_FOR_CONSOLE);
}
#endif
 
static uintptr_t sbi_clear_ipi(void)
{
        clear_csr(mip, MIP_SSIP);
        return 0;
}
 
/*
 * sbi is triggered by the s-mode ecall
 * parameter : register a0 a1 a2
 * function  : register a7
 * return    : register a0
 */
void handle_sbi(trapframe *tf)
{
        uintptr_t ret = 0;
        uintptr_t arg0 = tf->gpr[10];
        __unused uintptr_t arg1 = tf->gpr[11];
        uintptr_t which = tf->gpr[17];
 
        switch (which) {
        case SBI_SET_TIMER:
#if __riscv_xlen == 32
                ret = sbi_set_timer(arg0 + ((uint64_t)arg1 << 32));
#else
                ret = sbi_set_timer(arg0);
#endif
                break;
#if CONFIG(CONSOLE_SERIAL)
        case SBI_CONSOLE_PUTCHAR:
                ret = sbi_console_putchar(arg0);
                break;
        case SBI_CONSOLE_GETCHAR:
                ret = sbi_console_getchar();
                break;
#endif
        case SBI_CLEAR_IPI:
                ret = sbi_clear_ipi();
                break;
        case SBI_SEND_IPI:
                ret = send_ipi((uintptr_t *)arg0, IPI_SOFT);
                break;
        case SBI_REMOTE_FENCE_I:
                ret = send_ipi((uintptr_t *)arg0, IPI_FENCE_I);
                break;
        case SBI_REMOTE_SFENCE_VMA:
                ret = send_ipi((uintptr_t *)arg0, IPI_SFENCE_VMA);
                break;
        case SBI_REMOTE_SFENCE_VMA_ASID:
                ret = send_ipi((uintptr_t *)arg0, IPI_SFENCE_VMA_ASID);
                break;
        case SBI_SHUTDOWN:
                ret = send_ipi((uintptr_t *)arg0, IPI_SHUTDOWN);
                break;
        default:
                ret = -SBI_ENOSYS;
                break;
        }
        tf->gpr[10] = ret;
        write_csr(mepc, read_csr(mepc) + 4);
}