1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * ePAPR para-virtualization support.
4 *
5 * Copyright (C) 2012 Freescale Semiconductor, Inc.
6 */
7
8 #include <linux/of.h>
9 #include <linux/of_fdt.h>
10 #include <asm/epapr_hcalls.h>
11 #include <asm/cacheflush.h>
12 #include <asm/code-patching.h>
13 #include <asm/machdep.h>
14
15 #if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
16 extern void epapr_ev_idle(void);
17 extern u32 epapr_ev_idle_start[];
18 #endif
19
20 bool epapr_paravirt_enabled;
21 static bool __maybe_unused epapr_has_idle;
22
early_init_dt_scan_epapr(unsigned long node,const char * uname,int depth,void * data)23 static int __init early_init_dt_scan_epapr(unsigned long node,
24 const char *uname,
25 int depth, void *data)
26 {
27 const u32 *insts;
28 int len;
29 int i;
30
31 insts = of_get_flat_dt_prop(node, "hcall-instructions", &len);
32 if (!insts)
33 return 0;
34
35 if (len % 4 || len > (4 * 4))
36 return -1;
37
38 for (i = 0; i < (len / 4); i++) {
39 u32 inst = be32_to_cpu(insts[i]);
40 patch_instruction(epapr_hypercall_start + i, inst);
41 #if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
42 patch_instruction(epapr_ev_idle_start + i, inst);
43 #endif
44 }
45
46 #if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
47 if (of_get_flat_dt_prop(node, "has-idle", NULL))
48 epapr_has_idle = true;
49 #endif
50
51 epapr_paravirt_enabled = true;
52
53 return 1;
54 }
55
epapr_paravirt_early_init(void)56 int __init epapr_paravirt_early_init(void)
57 {
58 of_scan_flat_dt(early_init_dt_scan_epapr, NULL);
59
60 return 0;
61 }
62
epapr_idle_init(void)63 static int __init epapr_idle_init(void)
64 {
65 #if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
66 if (epapr_has_idle)
67 ppc_md.power_save = epapr_ev_idle;
68 #endif
69
70 return 0;
71 }
72
73 postcore_initcall(epapr_idle_init);
74