linux/linux-5.18.11/arch/powerpc/boot/opal.c

98 lines
2.2 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (c) 2016 IBM Corporation.
*/
#include "ops.h"
#include "stdio.h"
#include "io.h"
#include <libfdt.h>
#include "../include/asm/opal-api.h"
/* Global OPAL struct used by opal-call.S */
struct opal {
u64 base;
u64 entry;
} opal;
static u32 opal_con_id;
/* see opal-wrappers.S */
int64_t opal_console_write(int64_t term_number, u64 *length, const u8 *buffer);
int64_t opal_console_read(int64_t term_number, uint64_t *length, u8 *buffer);
int64_t opal_console_write_buffer_space(uint64_t term_number, uint64_t *length);
int64_t opal_console_flush(uint64_t term_number);
int64_t opal_poll_events(uint64_t *outstanding_event_mask);
void opal_kentry(unsigned long fdt_addr, void *vmlinux_addr);
static int opal_con_open(void)
{
/*
* When OPAL loads the boot kernel it stashes the OPAL base and entry
* address in r8 and r9 so the kernel can use the OPAL console
* before unflattening the devicetree. While executing the wrapper will
* probably trash r8 and r9 so this kentry hook restores them before
* entering the decompressed kernel.
*/
platform_ops.kentry = opal_kentry;
return 0;
}
static void opal_con_putc(unsigned char c)
{
int64_t rc;
uint64_t olen, len;
do {
rc = opal_console_write_buffer_space(opal_con_id, &olen);
len = be64_to_cpu(olen);
if (rc)
return;
opal_poll_events(NULL);
} while (len < 1);
olen = cpu_to_be64(1);
opal_console_write(opal_con_id, &olen, &c);
}
static void opal_con_close(void)
{
opal_console_flush(opal_con_id);
}
static void opal_init(void)
{
void *opal_node;
opal_node = finddevice("/ibm,opal");
if (!opal_node)
return;
if (getprop(opal_node, "opal-base-address", &opal.base, sizeof(u64)) < 0)
return;
opal.base = be64_to_cpu(opal.base);
if (getprop(opal_node, "opal-entry-address", &opal.entry, sizeof(u64)) < 0)
return;
opal.entry = be64_to_cpu(opal.entry);
}
int opal_console_init(void *devp, struct serial_console_data *scdp)
{
opal_init();
if (devp) {
int n = getprop(devp, "reg", &opal_con_id, sizeof(u32));
if (n != sizeof(u32))
return -1;
opal_con_id = be32_to_cpu(opal_con_id);
} else
opal_con_id = 0;
scdp->open = opal_con_open;
scdp->putc = opal_con_putc;
scdp->close = opal_con_close;
return 0;
}