xref: /openbmc/linux/arch/s390/boot/ipl_parm.c (revision 0a907292)
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/ebcdic.h>
7 #include <asm/sclp.h>
8 #include <asm/sections.h>
9 #include <asm/boot_data.h>
10 #include <asm/facility.h>
11 #include <asm/uv.h>
12 #include "boot.h"
13 
14 char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
15 int __bootdata(noexec_disabled);
16 
17 unsigned int __bootdata_preserved(zlib_dfltcc_support) = ZLIB_DFLTCC_FULL;
18 struct ipl_parameter_block __bootdata_preserved(ipl_block);
19 int __bootdata_preserved(ipl_block_valid);
20 
21 unsigned long vmalloc_size = VMALLOC_DEFAULT_SIZE;
22 unsigned long memory_limit;
23 int vmalloc_size_set;
24 int kaslr_enabled;
25 
26 static inline int __diag308(unsigned long subcode, void *addr)
27 {
28 	unsigned long reg1, reg2;
29 	union register_pair r1;
30 	psw_t old;
31 
32 	r1.even = (unsigned long) addr;
33 	r1.odd	= 0;
34 	asm volatile(
35 		"	mvc	0(16,%[psw_old]),0(%[psw_pgm])\n"
36 		"	epsw	%[reg1],%[reg2]\n"
37 		"	st	%[reg1],0(%[psw_pgm])\n"
38 		"	st	%[reg2],4(%[psw_pgm])\n"
39 		"	larl	%[reg1],1f\n"
40 		"	stg	%[reg1],8(%[psw_pgm])\n"
41 		"	diag	%[r1],%[subcode],0x308\n"
42 		"1:	mvc	0(16,%[psw_pgm]),0(%[psw_old])\n"
43 		: [r1] "+&d" (r1.pair),
44 		  [reg1] "=&d" (reg1),
45 		  [reg2] "=&a" (reg2),
46 		  "+Q" (S390_lowcore.program_new_psw),
47 		  "=Q" (old)
48 		: [subcode] "d" (subcode),
49 		  [psw_old] "a" (&old),
50 		  [psw_pgm] "a" (&S390_lowcore.program_new_psw)
51 		: "cc", "memory");
52 	return r1.odd;
53 }
54 
55 void store_ipl_parmblock(void)
56 {
57 	int rc;
58 
59 	rc = __diag308(DIAG308_STORE, &ipl_block);
60 	if (rc == DIAG308_RC_OK &&
61 	    ipl_block.hdr.version <= IPL_MAX_SUPPORTED_VERSION)
62 		ipl_block_valid = 1;
63 }
64 
65 bool is_ipl_block_dump(void)
66 {
67 	if (ipl_block.pb0_hdr.pbt == IPL_PBT_FCP &&
68 	    ipl_block.fcp.opt == IPL_PB0_FCP_OPT_DUMP)
69 		return true;
70 	if (ipl_block.pb0_hdr.pbt == IPL_PBT_NVME &&
71 	    ipl_block.nvme.opt == IPL_PB0_NVME_OPT_DUMP)
72 		return true;
73 	return false;
74 }
75 
76 static size_t scpdata_length(const u8 *buf, size_t count)
77 {
78 	while (count) {
79 		if (buf[count - 1] != '\0' && buf[count - 1] != ' ')
80 			break;
81 		count--;
82 	}
83 	return count;
84 }
85 
86 static size_t ipl_block_get_ascii_scpdata(char *dest, size_t size,
87 					  const struct ipl_parameter_block *ipb)
88 {
89 	const __u8 *scp_data;
90 	__u32 scp_data_len;
91 	int has_lowercase;
92 	size_t count = 0;
93 	size_t i;
94 
95 	switch (ipb->pb0_hdr.pbt) {
96 	case IPL_PBT_FCP:
97 		scp_data_len = ipb->fcp.scp_data_len;
98 		scp_data = ipb->fcp.scp_data;
99 		break;
100 	case IPL_PBT_NVME:
101 		scp_data_len = ipb->nvme.scp_data_len;
102 		scp_data = ipb->nvme.scp_data;
103 		break;
104 	default:
105 		goto out;
106 	}
107 
108 	count = min(size - 1, scpdata_length(scp_data, scp_data_len));
109 	if (!count)
110 		goto out;
111 
112 	has_lowercase = 0;
113 	for (i = 0; i < count; i++) {
114 		if (!isascii(scp_data[i])) {
115 			count = 0;
116 			goto out;
117 		}
118 		if (!has_lowercase && islower(scp_data[i]))
119 			has_lowercase = 1;
120 	}
121 
122 	if (has_lowercase)
123 		memcpy(dest, scp_data, count);
124 	else
125 		for (i = 0; i < count; i++)
126 			dest[i] = tolower(scp_data[i]);
127 out:
128 	dest[count] = '\0';
129 	return count;
130 }
131 
132 static void append_ipl_block_parm(void)
133 {
134 	char *parm, *delim;
135 	size_t len, rc = 0;
136 
137 	len = strlen(early_command_line);
138 
139 	delim = early_command_line + len;    /* '\0' character position */
140 	parm = early_command_line + len + 1; /* append right after '\0' */
141 
142 	switch (ipl_block.pb0_hdr.pbt) {
143 	case IPL_PBT_CCW:
144 		rc = ipl_block_get_ascii_vmparm(
145 			parm, COMMAND_LINE_SIZE - len - 1, &ipl_block);
146 		break;
147 	case IPL_PBT_FCP:
148 	case IPL_PBT_NVME:
149 		rc = ipl_block_get_ascii_scpdata(
150 			parm, COMMAND_LINE_SIZE - len - 1, &ipl_block);
151 		break;
152 	}
153 	if (rc) {
154 		if (*parm == '=')
155 			memmove(early_command_line, parm + 1, rc);
156 		else
157 			*delim = ' '; /* replace '\0' with space */
158 	}
159 }
160 
161 static inline int has_ebcdic_char(const char *str)
162 {
163 	int i;
164 
165 	for (i = 0; str[i]; i++)
166 		if (str[i] & 0x80)
167 			return 1;
168 	return 0;
169 }
170 
171 void setup_boot_command_line(void)
172 {
173 	parmarea.command_line[COMMAND_LINE_SIZE - 1] = 0;
174 	/* convert arch command line to ascii if necessary */
175 	if (has_ebcdic_char(parmarea.command_line))
176 		EBCASC(parmarea.command_line, COMMAND_LINE_SIZE);
177 	/* copy arch command line */
178 	strcpy(early_command_line, strim(parmarea.command_line));
179 
180 	/* append IPL PARM data to the boot command line */
181 	if (!is_prot_virt_guest() && ipl_block_valid)
182 		append_ipl_block_parm();
183 }
184 
185 static void modify_facility(unsigned long nr, bool clear)
186 {
187 	if (clear)
188 		__clear_facility(nr, stfle_fac_list);
189 	else
190 		__set_facility(nr, stfle_fac_list);
191 }
192 
193 static void check_cleared_facilities(void)
194 {
195 	unsigned long als[] = { FACILITIES_ALS };
196 	int i;
197 
198 	for (i = 0; i < ARRAY_SIZE(als); i++) {
199 		if ((stfle_fac_list[i] & als[i]) != als[i]) {
200 			sclp_early_printk("Warning: The Linux kernel requires facilities cleared via command line option\n");
201 			print_missing_facilities();
202 			break;
203 		}
204 	}
205 }
206 
207 static void modify_fac_list(char *str)
208 {
209 	unsigned long val, endval;
210 	char *endp;
211 	bool clear;
212 
213 	while (*str) {
214 		clear = false;
215 		if (*str == '!') {
216 			clear = true;
217 			str++;
218 		}
219 		val = simple_strtoull(str, &endp, 0);
220 		if (str == endp)
221 			break;
222 		str = endp;
223 		if (*str == '-') {
224 			str++;
225 			endval = simple_strtoull(str, &endp, 0);
226 			if (str == endp)
227 				break;
228 			str = endp;
229 			while (val <= endval) {
230 				modify_facility(val, clear);
231 				val++;
232 			}
233 		} else {
234 			modify_facility(val, clear);
235 		}
236 		if (*str != ',')
237 			break;
238 		str++;
239 	}
240 	check_cleared_facilities();
241 }
242 
243 static char command_line_buf[COMMAND_LINE_SIZE];
244 void parse_boot_command_line(void)
245 {
246 	char *param, *val;
247 	bool enabled;
248 	char *args;
249 	int rc;
250 
251 	kaslr_enabled = IS_ENABLED(CONFIG_RANDOMIZE_BASE);
252 	args = strcpy(command_line_buf, early_command_line);
253 	while (*args) {
254 		args = next_arg(args, &param, &val);
255 
256 		if (!strcmp(param, "mem") && val)
257 			memory_limit = round_down(memparse(val, NULL), PAGE_SIZE);
258 
259 		if (!strcmp(param, "vmalloc") && val) {
260 			vmalloc_size = round_up(memparse(val, NULL), PAGE_SIZE);
261 			vmalloc_size_set = 1;
262 		}
263 
264 		if (!strcmp(param, "dfltcc") && val) {
265 			if (!strcmp(val, "off"))
266 				zlib_dfltcc_support = ZLIB_DFLTCC_DISABLED;
267 			else if (!strcmp(val, "on"))
268 				zlib_dfltcc_support = ZLIB_DFLTCC_FULL;
269 			else if (!strcmp(val, "def_only"))
270 				zlib_dfltcc_support = ZLIB_DFLTCC_DEFLATE_ONLY;
271 			else if (!strcmp(val, "inf_only"))
272 				zlib_dfltcc_support = ZLIB_DFLTCC_INFLATE_ONLY;
273 			else if (!strcmp(val, "always"))
274 				zlib_dfltcc_support = ZLIB_DFLTCC_FULL_DEBUG;
275 		}
276 
277 		if (!strcmp(param, "noexec")) {
278 			rc = kstrtobool(val, &enabled);
279 			if (!rc && !enabled)
280 				noexec_disabled = 1;
281 		}
282 
283 		if (!strcmp(param, "facilities") && val)
284 			modify_fac_list(val);
285 
286 		if (!strcmp(param, "nokaslr"))
287 			kaslr_enabled = 0;
288 
289 #if IS_ENABLED(CONFIG_KVM)
290 		if (!strcmp(param, "prot_virt")) {
291 			rc = kstrtobool(val, &enabled);
292 			if (!rc && enabled)
293 				prot_virt_host = 1;
294 		}
295 #endif
296 	}
297 }
298