linux/arch/powerpc/boot/opal.c
Oliver O'Halloran 656ad58ef1 powerpc/boot: Add OPAL console to epapr wrappers
This patch adds an OPAL console backend to the powerpc boot wrapper so
that decompression failures inside the wrapper can be reported to the
user. This is important since it typically indicates data corruption in
the firmware and other nasty things.

Currently this only works when building a little endian kernel. When
compiling a 64 bit BE kernel the wrapper is always build 32 bit to be
compatible with some 32 bit firmwares. BE support will be added at a
later date. Another limitation of this is that only the "raw" type of
OPAL console is supported, however machines that provide a hvsi console
also provide a raw console so this is not an issue in practice.

Actually-written-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
[mpe: Move #ifdef __powerpc64__ to avoid warnings on 32-bit]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-07-05 23:58:54 +10:00

99 lines
2.1 KiB
C

/*
* Copyright (c) 2016 IBM Corporation.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include "ops.h"
#include "stdio.h"
#include "io.h"
#include <libfdt.h>
#include "../include/asm/opal-api.h"
#ifdef __powerpc64__
/* Global OPAL struct used by opal-call.S */
struct opal {
u64 base;
u64 entry;
} opal;
static u32 opal_con_id;
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);
static int opal_con_open(void)
{
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;
}
#else
int opal_console_init(void *devp, struct serial_console_data *scdp)
{
return -1;
}
#endif /* __powerpc64__ */