Files
opensbi/lib/sbi/sbi_ecall_dbcn.c
Andrew Jones f58c14090f lib: sbi: Introduce register_extensions extension callback
Rather than registering all extensions on their behalf in
sbi_ecall_init(), introduce another extension callback and
invoke that instead. For now, implement each callback by
simply registering the extension, which means this patch
has no intended functional change. In later patches, extension
callbacks will be modified to choose when to register and to
possibly narrow the extension ID range prior to registering.
When an extension range needs to remove IDs, leaving gaps, then
multiple invocations of sbi_ecall_register_extension() may be
used. In summary, later patches for current extensions and the
introductions of future extensions will use the new callback to
ensure that only valid extension IDs from the initial range,
which are also available, will be registered.

Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
2023-05-21 16:27:38 +05:30

81 lines
2.0 KiB
C

/*
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2022 Ventana Micro Systems Inc.
*
* Authors:
* Anup Patel <apatel@ventanamicro.com>
*/
#include <sbi/sbi_console.h>
#include <sbi/sbi_domain.h>
#include <sbi/sbi_error.h>
#include <sbi/sbi_ecall.h>
#include <sbi/sbi_ecall_interface.h>
#include <sbi/sbi_trap.h>
#include <sbi/riscv_asm.h>
static int sbi_ecall_dbcn_handler(unsigned long extid, unsigned long funcid,
const struct sbi_trap_regs *regs,
unsigned long *out_val,
struct sbi_trap_info *out_trap)
{
ulong smode = (csr_read(CSR_MSTATUS) & MSTATUS_MPP) >>
MSTATUS_MPP_SHIFT;
switch (funcid) {
case SBI_EXT_DBCN_CONSOLE_WRITE:
case SBI_EXT_DBCN_CONSOLE_READ:
/*
* On RV32, the M-mode can only access the first 4GB of
* the physical address space because M-mode does not have
* MMU to access full 34-bit physical address space.
*
* Based on above, we simply fail if the upper 32bits of
* the physical address (i.e. a2 register) is non-zero on
* RV32.
*/
#if __riscv_xlen == 32
if (regs->a2)
return SBI_ERR_FAILED;
#endif
if (!sbi_domain_check_addr_range(sbi_domain_thishart_ptr(),
regs->a1, regs->a0, smode,
SBI_DOMAIN_READ|SBI_DOMAIN_WRITE))
return SBI_ERR_INVALID_PARAM;
if (funcid == SBI_EXT_DBCN_CONSOLE_WRITE)
*out_val = sbi_nputs((const char *)regs->a1, regs->a0);
else
*out_val = sbi_ngets((char *)regs->a1, regs->a0);
return 0;
case SBI_EXT_DBCN_CONSOLE_WRITE_BYTE:
sbi_putc(regs->a0);
return 0;
default:
break;
}
return SBI_ENOTSUPP;
}
static int sbi_ecall_dbcn_probe(unsigned long extid, unsigned long *out_val)
{
*out_val = sbi_console_get_device() ? 1 : 0;
return 0;
}
struct sbi_ecall_extension ecall_dbcn;
static int sbi_ecall_dbcn_register_extensions(void)
{
return sbi_ecall_register_extension(&ecall_dbcn);
}
struct sbi_ecall_extension ecall_dbcn = {
.extid_start = SBI_EXT_DBCN,
.extid_end = SBI_EXT_DBCN,
.register_extensions = sbi_ecall_dbcn_register_extensions,
.probe = sbi_ecall_dbcn_probe,
.handle = sbi_ecall_dbcn_handler,
};