// 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; }