xref: /openbmc/linux/arch/s390/boot/ipl_parm.c (revision 95777591)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/kernel.h>
3 #include <linux/init.h>
4 #include <linux/ctype.h>
5 #include <asm/ebcdic.h>
6 #include <asm/sclp.h>
7 #include <asm/sections.h>
8 #include <asm/boot_data.h>
9 #include <asm/facility.h>
10 #include "boot.h"
11 
12 char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
13 struct ipl_parameter_block __bootdata(early_ipl_block);
14 int __bootdata(early_ipl_block_valid);
15 
16 unsigned long __bootdata(memory_end);
17 int __bootdata(memory_end_set);
18 int __bootdata(noexec_disabled);
19 
20 static inline int __diag308(unsigned long subcode, void *addr)
21 {
22 	register unsigned long _addr asm("0") = (unsigned long)addr;
23 	register unsigned long _rc asm("1") = 0;
24 	unsigned long reg1, reg2;
25 	psw_t old = S390_lowcore.program_new_psw;
26 
27 	asm volatile(
28 		"	epsw	%0,%1\n"
29 		"	st	%0,%[psw_pgm]\n"
30 		"	st	%1,%[psw_pgm]+4\n"
31 		"	larl	%0,1f\n"
32 		"	stg	%0,%[psw_pgm]+8\n"
33 		"	diag	%[addr],%[subcode],0x308\n"
34 		"1:	nopr	%%r7\n"
35 		: "=&d" (reg1), "=&a" (reg2),
36 		  [psw_pgm] "=Q" (S390_lowcore.program_new_psw),
37 		  [addr] "+d" (_addr), "+d" (_rc)
38 		: [subcode] "d" (subcode)
39 		: "cc", "memory");
40 	S390_lowcore.program_new_psw = old;
41 	return _rc;
42 }
43 
44 void store_ipl_parmblock(void)
45 {
46 	int rc;
47 
48 	rc = __diag308(DIAG308_STORE, &early_ipl_block);
49 	if (rc == DIAG308_RC_OK &&
50 	    early_ipl_block.hdr.version <= IPL_MAX_SUPPORTED_VERSION)
51 		early_ipl_block_valid = 1;
52 }
53 
54 static size_t scpdata_length(const char *buf, size_t count)
55 {
56 	while (count) {
57 		if (buf[count - 1] != '\0' && buf[count - 1] != ' ')
58 			break;
59 		count--;
60 	}
61 	return count;
62 }
63 
64 static size_t ipl_block_get_ascii_scpdata(char *dest, size_t size,
65 					  const struct ipl_parameter_block *ipb)
66 {
67 	size_t count;
68 	size_t i;
69 	int has_lowercase;
70 
71 	count = min(size - 1, scpdata_length(ipb->ipl_info.fcp.scp_data,
72 					     ipb->ipl_info.fcp.scp_data_len));
73 	if (!count)
74 		goto out;
75 
76 	has_lowercase = 0;
77 	for (i = 0; i < count; i++) {
78 		if (!isascii(ipb->ipl_info.fcp.scp_data[i])) {
79 			count = 0;
80 			goto out;
81 		}
82 		if (!has_lowercase && islower(ipb->ipl_info.fcp.scp_data[i]))
83 			has_lowercase = 1;
84 	}
85 
86 	if (has_lowercase)
87 		memcpy(dest, ipb->ipl_info.fcp.scp_data, count);
88 	else
89 		for (i = 0; i < count; i++)
90 			dest[i] = tolower(ipb->ipl_info.fcp.scp_data[i]);
91 out:
92 	dest[count] = '\0';
93 	return count;
94 }
95 
96 static void append_ipl_block_parm(void)
97 {
98 	char *parm, *delim;
99 	size_t len, rc = 0;
100 
101 	len = strlen(early_command_line);
102 
103 	delim = early_command_line + len;    /* '\0' character position */
104 	parm = early_command_line + len + 1; /* append right after '\0' */
105 
106 	switch (early_ipl_block.hdr.pbt) {
107 	case DIAG308_IPL_TYPE_CCW:
108 		rc = ipl_block_get_ascii_vmparm(
109 			parm, COMMAND_LINE_SIZE - len - 1, &early_ipl_block);
110 		break;
111 	case DIAG308_IPL_TYPE_FCP:
112 		rc = ipl_block_get_ascii_scpdata(
113 			parm, COMMAND_LINE_SIZE - len - 1, &early_ipl_block);
114 		break;
115 	}
116 	if (rc) {
117 		if (*parm == '=')
118 			memmove(early_command_line, parm + 1, rc);
119 		else
120 			*delim = ' '; /* replace '\0' with space */
121 	}
122 }
123 
124 static inline int has_ebcdic_char(const char *str)
125 {
126 	int i;
127 
128 	for (i = 0; str[i]; i++)
129 		if (str[i] & 0x80)
130 			return 1;
131 	return 0;
132 }
133 
134 void setup_boot_command_line(void)
135 {
136 	COMMAND_LINE[ARCH_COMMAND_LINE_SIZE - 1] = 0;
137 	/* convert arch command line to ascii if necessary */
138 	if (has_ebcdic_char(COMMAND_LINE))
139 		EBCASC(COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
140 	/* copy arch command line */
141 	strcpy(early_command_line, strim(COMMAND_LINE));
142 
143 	/* append IPL PARM data to the boot command line */
144 	if (early_ipl_block_valid)
145 		append_ipl_block_parm();
146 }
147 
148 static void modify_facility(unsigned long nr, bool clear)
149 {
150 	if (clear)
151 		__clear_facility(nr, S390_lowcore.stfle_fac_list);
152 	else
153 		__set_facility(nr, S390_lowcore.stfle_fac_list);
154 }
155 
156 static void check_cleared_facilities(void)
157 {
158 	unsigned long als[] = { FACILITIES_ALS };
159 	int i;
160 
161 	for (i = 0; i < ARRAY_SIZE(als); i++) {
162 		if ((S390_lowcore.stfle_fac_list[i] & als[i]) != als[i]) {
163 			sclp_early_printk("Warning: The Linux kernel requires facilities cleared via command line option\n");
164 			print_missing_facilities();
165 			break;
166 		}
167 	}
168 }
169 
170 static void modify_fac_list(char *str)
171 {
172 	unsigned long val, endval;
173 	char *endp;
174 	bool clear;
175 
176 	while (*str) {
177 		clear = false;
178 		if (*str == '!') {
179 			clear = true;
180 			str++;
181 		}
182 		val = simple_strtoull(str, &endp, 0);
183 		if (str == endp)
184 			break;
185 		str = endp;
186 		if (*str == '-') {
187 			str++;
188 			endval = simple_strtoull(str, &endp, 0);
189 			if (str == endp)
190 				break;
191 			str = endp;
192 			while (val <= endval) {
193 				modify_facility(val, clear);
194 				val++;
195 			}
196 		} else {
197 			modify_facility(val, clear);
198 		}
199 		if (*str != ',')
200 			break;
201 		str++;
202 	}
203 	check_cleared_facilities();
204 }
205 
206 static char command_line_buf[COMMAND_LINE_SIZE] __section(.data);
207 void parse_boot_command_line(void)
208 {
209 	char *param, *val;
210 	bool enabled;
211 	char *args;
212 	int rc;
213 
214 	args = strcpy(command_line_buf, early_command_line);
215 	while (*args) {
216 		args = next_arg(args, &param, &val);
217 
218 		if (!strcmp(param, "mem")) {
219 			memory_end = memparse(val, NULL);
220 			memory_end_set = 1;
221 		}
222 
223 		if (!strcmp(param, "noexec")) {
224 			rc = kstrtobool(val, &enabled);
225 			if (!rc && !enabled)
226 				noexec_disabled = 1;
227 		}
228 
229 		if (!strcmp(param, "facilities"))
230 			modify_fac_list(val);
231 	}
232 }
233 
234 void setup_memory_end(void)
235 {
236 #ifdef CONFIG_CRASH_DUMP
237 	if (!OLDMEM_BASE && early_ipl_block_valid &&
238 	    early_ipl_block.hdr.pbt == DIAG308_IPL_TYPE_FCP &&
239 	    early_ipl_block.ipl_info.fcp.opt == DIAG308_IPL_OPT_DUMP) {
240 		if (!sclp_early_get_hsa_size(&memory_end) && memory_end)
241 			memory_end_set = 1;
242 	}
243 #endif
244 }
245