xref: /linux/arch/s390/boot/ipl_parm.c (revision 1553a1c48281243359a9529a10ddb551f3b967ab)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/kernel.h>
3 #include <linux/init.h>
4 #include <linux/ctype.h>
5 #include <linux/pgtable.h>
6 #include <asm/page-states.h>
7 #include <asm/ebcdic.h>
8 #include <asm/sclp.h>
9 #include <asm/sections.h>
10 #include <asm/boot_data.h>
11 #include <asm/facility.h>
12 #include <asm/setup.h>
13 #include <asm/uv.h>
14 #include "boot.h"
15 
16 struct parmarea parmarea __section(".parmarea") = {
17 	.kernel_version		= (unsigned long)kernel_version,
18 	.max_command_line_size	= COMMAND_LINE_SIZE,
19 	.command_line		= "root=/dev/ram0 ro",
20 };
21 
22 char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
23 
24 unsigned int __bootdata_preserved(zlib_dfltcc_support) = ZLIB_DFLTCC_FULL;
25 struct ipl_parameter_block __bootdata_preserved(ipl_block);
26 int __bootdata_preserved(ipl_block_valid);
27 int __bootdata_preserved(__kaslr_enabled);
28 int __bootdata_preserved(cmma_flag) = 1;
29 
30 unsigned long vmalloc_size = VMALLOC_DEFAULT_SIZE;
31 unsigned long memory_limit;
32 int vmalloc_size_set;
33 
34 static inline int __diag308(unsigned long subcode, void *addr)
35 {
36 	unsigned long reg1, reg2;
37 	union register_pair r1;
38 	psw_t old;
39 
40 	r1.even = (unsigned long) addr;
41 	r1.odd	= 0;
42 	asm volatile(
43 		"	mvc	0(16,%[psw_old]),0(%[psw_pgm])\n"
44 		"	epsw	%[reg1],%[reg2]\n"
45 		"	st	%[reg1],0(%[psw_pgm])\n"
46 		"	st	%[reg2],4(%[psw_pgm])\n"
47 		"	larl	%[reg1],1f\n"
48 		"	stg	%[reg1],8(%[psw_pgm])\n"
49 		"	diag	%[r1],%[subcode],0x308\n"
50 		"1:	mvc	0(16,%[psw_pgm]),0(%[psw_old])\n"
51 		: [r1] "+&d" (r1.pair),
52 		  [reg1] "=&d" (reg1),
53 		  [reg2] "=&a" (reg2),
54 		  "+Q" (S390_lowcore.program_new_psw),
55 		  "=Q" (old)
56 		: [subcode] "d" (subcode),
57 		  [psw_old] "a" (&old),
58 		  [psw_pgm] "a" (&S390_lowcore.program_new_psw)
59 		: "cc", "memory");
60 	return r1.odd;
61 }
62 
63 void store_ipl_parmblock(void)
64 {
65 	int rc;
66 
67 	rc = __diag308(DIAG308_STORE, &ipl_block);
68 	if (rc == DIAG308_RC_OK &&
69 	    ipl_block.hdr.version <= IPL_MAX_SUPPORTED_VERSION)
70 		ipl_block_valid = 1;
71 }
72 
73 bool is_ipl_block_dump(void)
74 {
75 	if (ipl_block.pb0_hdr.pbt == IPL_PBT_FCP &&
76 	    ipl_block.fcp.opt == IPL_PB0_FCP_OPT_DUMP)
77 		return true;
78 	if (ipl_block.pb0_hdr.pbt == IPL_PBT_NVME &&
79 	    ipl_block.nvme.opt == IPL_PB0_NVME_OPT_DUMP)
80 		return true;
81 	if (ipl_block.pb0_hdr.pbt == IPL_PBT_ECKD &&
82 	    ipl_block.eckd.opt == IPL_PB0_ECKD_OPT_DUMP)
83 		return true;
84 	return false;
85 }
86 
87 static size_t scpdata_length(const u8 *buf, size_t count)
88 {
89 	while (count) {
90 		if (buf[count - 1] != '\0' && buf[count - 1] != ' ')
91 			break;
92 		count--;
93 	}
94 	return count;
95 }
96 
97 static size_t ipl_block_get_ascii_scpdata(char *dest, size_t size,
98 					  const struct ipl_parameter_block *ipb)
99 {
100 	const __u8 *scp_data;
101 	__u32 scp_data_len;
102 	int has_lowercase;
103 	size_t count = 0;
104 	size_t i;
105 
106 	switch (ipb->pb0_hdr.pbt) {
107 	case IPL_PBT_FCP:
108 		scp_data_len = ipb->fcp.scp_data_len;
109 		scp_data = ipb->fcp.scp_data;
110 		break;
111 	case IPL_PBT_NVME:
112 		scp_data_len = ipb->nvme.scp_data_len;
113 		scp_data = ipb->nvme.scp_data;
114 		break;
115 	case IPL_PBT_ECKD:
116 		scp_data_len = ipb->eckd.scp_data_len;
117 		scp_data = ipb->eckd.scp_data;
118 		break;
119 
120 	default:
121 		goto out;
122 	}
123 
124 	count = min(size - 1, scpdata_length(scp_data, scp_data_len));
125 	if (!count)
126 		goto out;
127 
128 	has_lowercase = 0;
129 	for (i = 0; i < count; i++) {
130 		if (!isascii(scp_data[i])) {
131 			count = 0;
132 			goto out;
133 		}
134 		if (!has_lowercase && islower(scp_data[i]))
135 			has_lowercase = 1;
136 	}
137 
138 	if (has_lowercase)
139 		memcpy(dest, scp_data, count);
140 	else
141 		for (i = 0; i < count; i++)
142 			dest[i] = tolower(scp_data[i]);
143 out:
144 	dest[count] = '\0';
145 	return count;
146 }
147 
148 static void append_ipl_block_parm(void)
149 {
150 	char *parm, *delim;
151 	size_t len, rc = 0;
152 
153 	len = strlen(early_command_line);
154 
155 	delim = early_command_line + len;    /* '\0' character position */
156 	parm = early_command_line + len + 1; /* append right after '\0' */
157 
158 	switch (ipl_block.pb0_hdr.pbt) {
159 	case IPL_PBT_CCW:
160 		rc = ipl_block_get_ascii_vmparm(
161 			parm, COMMAND_LINE_SIZE - len - 1, &ipl_block);
162 		break;
163 	case IPL_PBT_FCP:
164 	case IPL_PBT_NVME:
165 	case IPL_PBT_ECKD:
166 		rc = ipl_block_get_ascii_scpdata(
167 			parm, COMMAND_LINE_SIZE - len - 1, &ipl_block);
168 		break;
169 	}
170 	if (rc) {
171 		if (*parm == '=')
172 			memmove(early_command_line, parm + 1, rc);
173 		else
174 			*delim = ' '; /* replace '\0' with space */
175 	}
176 }
177 
178 static inline int has_ebcdic_char(const char *str)
179 {
180 	int i;
181 
182 	for (i = 0; str[i]; i++)
183 		if (str[i] & 0x80)
184 			return 1;
185 	return 0;
186 }
187 
188 void setup_boot_command_line(void)
189 {
190 	parmarea.command_line[COMMAND_LINE_SIZE - 1] = 0;
191 	/* convert arch command line to ascii if necessary */
192 	if (has_ebcdic_char(parmarea.command_line))
193 		EBCASC(parmarea.command_line, COMMAND_LINE_SIZE);
194 	/* copy arch command line */
195 	strcpy(early_command_line, strim(parmarea.command_line));
196 
197 	/* append IPL PARM data to the boot command line */
198 	if (!is_prot_virt_guest() && ipl_block_valid)
199 		append_ipl_block_parm();
200 }
201 
202 static void modify_facility(unsigned long nr, bool clear)
203 {
204 	if (clear)
205 		__clear_facility(nr, stfle_fac_list);
206 	else
207 		__set_facility(nr, stfle_fac_list);
208 }
209 
210 static void check_cleared_facilities(void)
211 {
212 	unsigned long als[] = { FACILITIES_ALS };
213 	int i;
214 
215 	for (i = 0; i < ARRAY_SIZE(als); i++) {
216 		if ((stfle_fac_list[i] & als[i]) != als[i]) {
217 			sclp_early_printk("Warning: The Linux kernel requires facilities cleared via command line option\n");
218 			print_missing_facilities();
219 			break;
220 		}
221 	}
222 }
223 
224 static void modify_fac_list(char *str)
225 {
226 	unsigned long val, endval;
227 	char *endp;
228 	bool clear;
229 
230 	while (*str) {
231 		clear = false;
232 		if (*str == '!') {
233 			clear = true;
234 			str++;
235 		}
236 		val = simple_strtoull(str, &endp, 0);
237 		if (str == endp)
238 			break;
239 		str = endp;
240 		if (*str == '-') {
241 			str++;
242 			endval = simple_strtoull(str, &endp, 0);
243 			if (str == endp)
244 				break;
245 			str = endp;
246 			while (val <= endval) {
247 				modify_facility(val, clear);
248 				val++;
249 			}
250 		} else {
251 			modify_facility(val, clear);
252 		}
253 		if (*str != ',')
254 			break;
255 		str++;
256 	}
257 	check_cleared_facilities();
258 }
259 
260 static char command_line_buf[COMMAND_LINE_SIZE];
261 void parse_boot_command_line(void)
262 {
263 	char *param, *val;
264 	bool enabled;
265 	char *args;
266 	int rc;
267 
268 	__kaslr_enabled = IS_ENABLED(CONFIG_RANDOMIZE_BASE);
269 	args = strcpy(command_line_buf, early_command_line);
270 	while (*args) {
271 		args = next_arg(args, &param, &val);
272 
273 		if (!strcmp(param, "mem") && val)
274 			memory_limit = round_down(memparse(val, NULL), PAGE_SIZE);
275 
276 		if (!strcmp(param, "vmalloc") && val) {
277 			vmalloc_size = round_up(memparse(val, NULL), _SEGMENT_SIZE);
278 			vmalloc_size_set = 1;
279 		}
280 
281 		if (!strcmp(param, "dfltcc") && val) {
282 			if (!strcmp(val, "off"))
283 				zlib_dfltcc_support = ZLIB_DFLTCC_DISABLED;
284 			else if (!strcmp(val, "on"))
285 				zlib_dfltcc_support = ZLIB_DFLTCC_FULL;
286 			else if (!strcmp(val, "def_only"))
287 				zlib_dfltcc_support = ZLIB_DFLTCC_DEFLATE_ONLY;
288 			else if (!strcmp(val, "inf_only"))
289 				zlib_dfltcc_support = ZLIB_DFLTCC_INFLATE_ONLY;
290 			else if (!strcmp(val, "always"))
291 				zlib_dfltcc_support = ZLIB_DFLTCC_FULL_DEBUG;
292 		}
293 
294 		if (!strcmp(param, "facilities") && val)
295 			modify_fac_list(val);
296 
297 		if (!strcmp(param, "nokaslr"))
298 			__kaslr_enabled = 0;
299 
300 		if (!strcmp(param, "cmma")) {
301 			rc = kstrtobool(val, &enabled);
302 			if (!rc && !enabled)
303 				cmma_flag = 0;
304 		}
305 
306 #if IS_ENABLED(CONFIG_KVM)
307 		if (!strcmp(param, "prot_virt")) {
308 			rc = kstrtobool(val, &enabled);
309 			if (!rc && enabled)
310 				prot_virt_host = 1;
311 		}
312 #endif
313 	}
314 }
315