1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * Firmware-Assisted Dump support on POWER platform (OPAL).
4  *
5  * Copyright 2019, Hari Bathini, IBM Corporation.
6  */
7 
8 #ifndef _POWERNV_OPAL_FADUMP_H
9 #define _POWERNV_OPAL_FADUMP_H
10 
11 #include <asm/reg.h>
12 
13 /*
14  * With kernel & initrd loaded at 512MB (with 256MB size), enforce a minimum
15  * boot memory size of 768MB to ensure f/w loading kernel and initrd doesn't
16  * mess with crash'ed kernel's memory during MPIPL.
17  */
18 #define OPAL_FADUMP_MIN_BOOT_MEM		(0x30000000UL)
19 
20 /*
21  * OPAL FADump metadata structure format version
22  *
23  * OPAL FADump kernel metadata structure stores kernel metadata needed to
24  * register-for/process crash dump. Format version is used to keep a tab on
25  * the changes in the structure format. The changes, if any, to the format
26  * are expected to be minimal and backward compatible.
27  */
28 #define OPAL_FADUMP_VERSION			0x1
29 
30 /*
31  * OPAL FADump kernel metadata
32  *
33  * The address of this structure will be registered with f/w for retrieving
34  * in the capture kernel to process the crash dump.
35  */
36 struct opal_fadump_mem_struct {
37 	u8	version;
38 	u8	reserved[3];
39 	__be16	region_cnt;		/* number of regions */
40 	__be16	registered_regions;	/* Regions registered for MPIPL */
41 	__be64	fadumphdr_addr;
42 	struct opal_mpipl_region	rgn[FADUMP_MAX_MEM_REGS];
43 } __packed;
44 
45 /*
46  * CPU state data
47  *
48  * CPU state data information is provided by f/w. The format for this data
49  * is defined in the HDAT spec. Version is used to keep a tab on the changes
50  * in this CPU state data format. Changes to this format are unlikely, but
51  * if there are any changes, please refer to latest HDAT specification.
52  */
53 #define HDAT_FADUMP_CPU_DATA_VER		1
54 
55 #define HDAT_FADUMP_CORE_INACTIVE		(0x0F)
56 
57 /* HDAT thread header for register entries */
58 struct hdat_fadump_thread_hdr {
59 	__be32  pir;
60 	/* 0x00 - 0x0F - The corresponding stop state of the core */
61 	u8      core_state;
62 	u8      reserved[3];
63 
64 	__be32	offset;	/* Offset to Register Entries array */
65 	__be32	ecnt;	/* Number of entries */
66 	__be32	esize;	/* Alloc size of each array entry in bytes */
67 	__be32	eactsz;	/* Actual size of each array entry in bytes */
68 } __packed;
69 
70 /* Register types populated by f/w */
71 #define HDAT_FADUMP_REG_TYPE_GPR		0x01
72 #define HDAT_FADUMP_REG_TYPE_SPR		0x02
73 
74 /* ID numbers used by f/w while populating certain registers */
75 #define HDAT_FADUMP_REG_ID_NIP			0x7D0
76 #define HDAT_FADUMP_REG_ID_MSR			0x7D1
77 #define HDAT_FADUMP_REG_ID_CCR			0x7D2
78 
79 /* HDAT register entry. */
80 struct hdat_fadump_reg_entry {
81 	__be32		reg_type;
82 	__be32		reg_num;
83 	__be64		reg_val;
84 } __packed;
85 
86 static inline void opal_fadump_set_regval_regnum(struct pt_regs *regs,
87 						 u32 reg_type, u32 reg_num,
88 						 u64 reg_val)
89 {
90 	if (reg_type == HDAT_FADUMP_REG_TYPE_GPR) {
91 		if (reg_num < 32)
92 			regs->gpr[reg_num] = reg_val;
93 		return;
94 	}
95 
96 	switch (reg_num) {
97 	case SPRN_CTR:
98 		regs->ctr = reg_val;
99 		break;
100 	case SPRN_LR:
101 		regs->link = reg_val;
102 		break;
103 	case SPRN_XER:
104 		regs->xer = reg_val;
105 		break;
106 	case SPRN_DAR:
107 		regs->dar = reg_val;
108 		break;
109 	case SPRN_DSISR:
110 		regs->dsisr = reg_val;
111 		break;
112 	case HDAT_FADUMP_REG_ID_NIP:
113 		regs->nip = reg_val;
114 		break;
115 	case HDAT_FADUMP_REG_ID_MSR:
116 		regs->msr = reg_val;
117 		break;
118 	case HDAT_FADUMP_REG_ID_CCR:
119 		regs->ccr = reg_val;
120 		break;
121 	}
122 }
123 
124 static inline void opal_fadump_read_regs(char *bufp, unsigned int regs_cnt,
125 					 unsigned int reg_entry_size,
126 					 bool cpu_endian,
127 					 struct pt_regs *regs)
128 {
129 	struct hdat_fadump_reg_entry *reg_entry;
130 	u64 val;
131 	int i;
132 
133 	memset(regs, 0, sizeof(struct pt_regs));
134 
135 	for (i = 0; i < regs_cnt; i++, bufp += reg_entry_size) {
136 		reg_entry = (struct hdat_fadump_reg_entry *)bufp;
137 		val = (cpu_endian ? be64_to_cpu(reg_entry->reg_val) :
138 		       (u64)(reg_entry->reg_val));
139 		opal_fadump_set_regval_regnum(regs,
140 					      be32_to_cpu(reg_entry->reg_type),
141 					      be32_to_cpu(reg_entry->reg_num),
142 					      val);
143 	}
144 }
145 
146 #endif /* _POWERNV_OPAL_FADUMP_H */
147