forked from Mirrors/opensbi
3284bea833
Some of the upcoming SBI extensions (such as SSE) will directly update register state so improve the prototype of ecall handler to accommodate this. Further, this flexibility allows us to push the trap redirection from sbi_ecall_handler() to the sbi_ecall_legacy_handler(). Signed-off-by: Anup Patel <apatel@ventanamicro.com>
82 lines
2.1 KiB
C
82 lines
2.1 KiB
C
/*
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* SPDX-License-Identifier: BSD-2-Clause
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*
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* Copyright (c) 2022 Ventana Micro Systems Inc.
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*
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* Authors:
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* Anup Patel <apatel@ventanamicro.com>
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*/
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#include <sbi/sbi_console.h>
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#include <sbi/sbi_domain.h>
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#include <sbi/sbi_error.h>
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#include <sbi/sbi_ecall.h>
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#include <sbi/sbi_ecall_interface.h>
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#include <sbi/sbi_trap.h>
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#include <sbi/riscv_asm.h>
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#include <sbi/sbi_hart.h>
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static int sbi_ecall_dbcn_handler(unsigned long extid, unsigned long funcid,
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struct sbi_trap_regs *regs,
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struct sbi_ecall_return *out)
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{
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ulong smode = (csr_read(CSR_MSTATUS) & MSTATUS_MPP) >>
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MSTATUS_MPP_SHIFT;
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switch (funcid) {
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case SBI_EXT_DBCN_CONSOLE_WRITE:
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case SBI_EXT_DBCN_CONSOLE_READ:
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/*
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* On RV32, the M-mode can only access the first 4GB of
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* the physical address space because M-mode does not have
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* MMU to access full 34-bit physical address space.
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*
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* Based on above, we simply fail if the upper 32bits of
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* the physical address (i.e. a2 register) is non-zero on
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* RV32.
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*
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* Analogously, we fail if the upper 64bit of the
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* physical address (i.e. a2 register) is non-zero on
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* RV64.
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*/
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if (regs->a2)
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return SBI_ERR_FAILED;
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if (!sbi_domain_check_addr_range(sbi_domain_thishart_ptr(),
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regs->a1, regs->a0, smode,
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SBI_DOMAIN_READ|SBI_DOMAIN_WRITE))
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return SBI_ERR_INVALID_PARAM;
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sbi_hart_map_saddr(regs->a1, regs->a0);
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if (funcid == SBI_EXT_DBCN_CONSOLE_WRITE)
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out->value = sbi_nputs((const char *)regs->a1, regs->a0);
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else
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out->value = sbi_ngets((char *)regs->a1, regs->a0);
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sbi_hart_unmap_saddr();
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return 0;
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case SBI_EXT_DBCN_CONSOLE_WRITE_BYTE:
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sbi_putc(regs->a0);
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return 0;
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default:
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break;
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}
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return SBI_ENOTSUPP;
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}
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struct sbi_ecall_extension ecall_dbcn;
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static int sbi_ecall_dbcn_register_extensions(void)
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{
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if (!sbi_console_get_device())
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return 0;
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return sbi_ecall_register_extension(&ecall_dbcn);
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}
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struct sbi_ecall_extension ecall_dbcn = {
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.extid_start = SBI_EXT_DBCN,
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.extid_end = SBI_EXT_DBCN,
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.register_extensions = sbi_ecall_dbcn_register_extensions,
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.handle = sbi_ecall_dbcn_handler,
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};
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