1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * p1275.c: Sun IEEE 1275 PROM low level interface routines
4  *
5  * Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
6  */
7 
8 #include <linux/kernel.h>
9 #include <linux/sched.h>
10 #include <linux/smp.h>
11 #include <linux/string.h>
12 #include <linux/spinlock.h>
13 #include <linux/irqflags.h>
14 
15 #include <asm/openprom.h>
16 #include <asm/oplib.h>
17 #include <asm/spitfire.h>
18 #include <asm/pstate.h>
19 #include <asm/ldc.h>
20 
21 struct {
22 	long prom_callback;			/* 0x00 */
23 	void (*prom_cif_handler)(long *);	/* 0x08 */
24 } p1275buf;
25 
26 extern void prom_world(int);
27 
28 extern void prom_cif_direct(unsigned long *args);
29 extern void prom_cif_callback(void);
30 
31 /*
32  * This provides SMP safety on the p1275buf.
33  */
34 DEFINE_RAW_SPINLOCK(prom_entry_lock);
35 
p1275_cmd_direct(unsigned long * args)36 void p1275_cmd_direct(unsigned long *args)
37 {
38 	unsigned long flags;
39 
40 	local_save_flags(flags);
41 	local_irq_restore((unsigned long)PIL_NMI);
42 	raw_spin_lock(&prom_entry_lock);
43 
44 	prom_world(1);
45 	prom_cif_direct(args);
46 	prom_world(0);
47 
48 	raw_spin_unlock(&prom_entry_lock);
49 	local_irq_restore(flags);
50 }
51 
prom_cif_init(void * cif_handler,void * cif_stack)52 void prom_cif_init(void *cif_handler, void *cif_stack)
53 {
54 	p1275buf.prom_cif_handler = (void (*)(long *))cif_handler;
55 }
56