102 lines
		
	
	
		
			2.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			102 lines
		
	
	
		
			2.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Copyright (c) 2016 IBM Corporation.
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|  *
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|  * This program is free software; you can redistribute it and/or
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|  * modify it under the terms of the GNU General Public License
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|  * as published by the Free Software Foundation; either version
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|  * 2 of the License, or (at your option) any later version.
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|  */
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| 
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| #include "ops.h"
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| #include "stdio.h"
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| #include "io.h"
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| #include <libfdt.h>
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| #include "../include/asm/opal-api.h"
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| 
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| /* Global OPAL struct used by opal-call.S */
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| struct opal {
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| 	u64 base;
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| 	u64 entry;
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| } opal;
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| 
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| static u32 opal_con_id;
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| 
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| /* see opal-wrappers.S */
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| int64_t opal_console_write(int64_t term_number, u64 *length, const u8 *buffer);
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| int64_t opal_console_read(int64_t term_number, uint64_t *length, u8 *buffer);
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| int64_t opal_console_write_buffer_space(uint64_t term_number, uint64_t *length);
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| int64_t opal_console_flush(uint64_t term_number);
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| int64_t opal_poll_events(uint64_t *outstanding_event_mask);
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| 
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| void opal_kentry(unsigned long fdt_addr, void *vmlinux_addr);
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| 
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| static int opal_con_open(void)
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| {
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| 	/*
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| 	 * When OPAL loads the boot kernel it stashes the OPAL base and entry
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| 	 * address in r8 and r9 so the kernel can use the OPAL console
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| 	 * before unflattening the devicetree. While executing the wrapper will
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| 	 * probably trash r8 and r9 so this kentry hook restores them before
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| 	 * entering the decompressed kernel.
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| 	 */
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| 	platform_ops.kentry = opal_kentry;
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| 	return 0;
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| }
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| 
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| static void opal_con_putc(unsigned char c)
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| {
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| 	int64_t rc;
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| 	uint64_t olen, len;
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| 
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| 	do {
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| 		rc = opal_console_write_buffer_space(opal_con_id, &olen);
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| 		len = be64_to_cpu(olen);
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| 		if (rc)
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| 			return;
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| 		opal_poll_events(NULL);
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| 	} while (len < 1);
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| 
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| 
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| 	olen = cpu_to_be64(1);
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| 	opal_console_write(opal_con_id, &olen, &c);
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| }
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| 
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| static void opal_con_close(void)
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| {
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| 	opal_console_flush(opal_con_id);
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| }
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| 
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| static void opal_init(void)
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| {
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| 	void *opal_node;
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| 
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| 	opal_node = finddevice("/ibm,opal");
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| 	if (!opal_node)
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| 		return;
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| 	if (getprop(opal_node, "opal-base-address", &opal.base, sizeof(u64)) < 0)
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| 		return;
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| 	opal.base = be64_to_cpu(opal.base);
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| 	if (getprop(opal_node, "opal-entry-address", &opal.entry, sizeof(u64)) < 0)
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| 		return;
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| 	opal.entry = be64_to_cpu(opal.entry);
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| }
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| 
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| int opal_console_init(void *devp, struct serial_console_data *scdp)
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| {
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| 	opal_init();
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| 
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| 	if (devp) {
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| 		int n = getprop(devp, "reg", &opal_con_id, sizeof(u32));
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| 		if (n != sizeof(u32))
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| 			return -1;
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| 		opal_con_id = be32_to_cpu(opal_con_id);
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| 	} else
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| 		opal_con_id = 0;
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| 
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| 	scdp->open = opal_con_open;
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| 	scdp->putc = opal_con_putc;
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| 	scdp->close = opal_con_close;
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| 
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| 	return 0;
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| }
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