xref: /openbmc/linux/arch/s390/boot/ipl_parm.c (revision 37744fee)
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 <asm/pgtable.h>
11 #include <asm/uv.h>
12 #include "boot.h"
13 
14 char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
15 struct ipl_parameter_block __bootdata_preserved(ipl_block);
16 int __bootdata_preserved(ipl_block_valid);
17 unsigned int __bootdata_preserved(zlib_dfltcc_support) = ZLIB_DFLTCC_FULL;
18 
19 unsigned long __bootdata(vmalloc_size) = VMALLOC_DEFAULT_SIZE;
20 unsigned long __bootdata(memory_end);
21 int __bootdata(memory_end_set);
22 int __bootdata(noexec_disabled);
23 
24 int kaslr_enabled __section(.data);
25 
26 static inline int __diag308(unsigned long subcode, void *addr)
27 {
28 	register unsigned long _addr asm("0") = (unsigned long)addr;
29 	register unsigned long _rc asm("1") = 0;
30 	unsigned long reg1, reg2;
31 	psw_t old = S390_lowcore.program_new_psw;
32 
33 	asm volatile(
34 		"	epsw	%0,%1\n"
35 		"	st	%0,%[psw_pgm]\n"
36 		"	st	%1,%[psw_pgm]+4\n"
37 		"	larl	%0,1f\n"
38 		"	stg	%0,%[psw_pgm]+8\n"
39 		"	diag	%[addr],%[subcode],0x308\n"
40 		"1:	nopr	%%r7\n"
41 		: "=&d" (reg1), "=&a" (reg2),
42 		  [psw_pgm] "=Q" (S390_lowcore.program_new_psw),
43 		  [addr] "+d" (_addr), "+d" (_rc)
44 		: [subcode] "d" (subcode)
45 		: "cc", "memory");
46 	S390_lowcore.program_new_psw = old;
47 	return _rc;
48 }
49 
50 void store_ipl_parmblock(void)
51 {
52 	int rc;
53 
54 	rc = __diag308(DIAG308_STORE, &ipl_block);
55 	if (rc == DIAG308_RC_OK &&
56 	    ipl_block.hdr.version <= IPL_MAX_SUPPORTED_VERSION)
57 		ipl_block_valid = 1;
58 }
59 
60 static size_t scpdata_length(const u8 *buf, size_t count)
61 {
62 	while (count) {
63 		if (buf[count - 1] != '\0' && buf[count - 1] != ' ')
64 			break;
65 		count--;
66 	}
67 	return count;
68 }
69 
70 static size_t ipl_block_get_ascii_scpdata(char *dest, size_t size,
71 					  const struct ipl_parameter_block *ipb)
72 {
73 	size_t count;
74 	size_t i;
75 	int has_lowercase;
76 
77 	count = min(size - 1, scpdata_length(ipb->fcp.scp_data,
78 					     ipb->fcp.scp_data_len));
79 	if (!count)
80 		goto out;
81 
82 	has_lowercase = 0;
83 	for (i = 0; i < count; i++) {
84 		if (!isascii(ipb->fcp.scp_data[i])) {
85 			count = 0;
86 			goto out;
87 		}
88 		if (!has_lowercase && islower(ipb->fcp.scp_data[i]))
89 			has_lowercase = 1;
90 	}
91 
92 	if (has_lowercase)
93 		memcpy(dest, ipb->fcp.scp_data, count);
94 	else
95 		for (i = 0; i < count; i++)
96 			dest[i] = tolower(ipb->fcp.scp_data[i]);
97 out:
98 	dest[count] = '\0';
99 	return count;
100 }
101 
102 static void append_ipl_block_parm(void)
103 {
104 	char *parm, *delim;
105 	size_t len, rc = 0;
106 
107 	len = strlen(early_command_line);
108 
109 	delim = early_command_line + len;    /* '\0' character position */
110 	parm = early_command_line + len + 1; /* append right after '\0' */
111 
112 	switch (ipl_block.pb0_hdr.pbt) {
113 	case IPL_PBT_CCW:
114 		rc = ipl_block_get_ascii_vmparm(
115 			parm, COMMAND_LINE_SIZE - len - 1, &ipl_block);
116 		break;
117 	case IPL_PBT_FCP:
118 		rc = ipl_block_get_ascii_scpdata(
119 			parm, COMMAND_LINE_SIZE - len - 1, &ipl_block);
120 		break;
121 	}
122 	if (rc) {
123 		if (*parm == '=')
124 			memmove(early_command_line, parm + 1, rc);
125 		else
126 			*delim = ' '; /* replace '\0' with space */
127 	}
128 }
129 
130 static inline int has_ebcdic_char(const char *str)
131 {
132 	int i;
133 
134 	for (i = 0; str[i]; i++)
135 		if (str[i] & 0x80)
136 			return 1;
137 	return 0;
138 }
139 
140 void setup_boot_command_line(void)
141 {
142 	COMMAND_LINE[ARCH_COMMAND_LINE_SIZE - 1] = 0;
143 	/* convert arch command line to ascii if necessary */
144 	if (has_ebcdic_char(COMMAND_LINE))
145 		EBCASC(COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
146 	/* copy arch command line */
147 	strcpy(early_command_line, strim(COMMAND_LINE));
148 
149 	/* append IPL PARM data to the boot command line */
150 	if (!is_prot_virt_guest() && ipl_block_valid)
151 		append_ipl_block_parm();
152 }
153 
154 static void modify_facility(unsigned long nr, bool clear)
155 {
156 	if (clear)
157 		__clear_facility(nr, S390_lowcore.stfle_fac_list);
158 	else
159 		__set_facility(nr, S390_lowcore.stfle_fac_list);
160 }
161 
162 static void check_cleared_facilities(void)
163 {
164 	unsigned long als[] = { FACILITIES_ALS };
165 	int i;
166 
167 	for (i = 0; i < ARRAY_SIZE(als); i++) {
168 		if ((S390_lowcore.stfle_fac_list[i] & als[i]) != als[i]) {
169 			sclp_early_printk("Warning: The Linux kernel requires facilities cleared via command line option\n");
170 			print_missing_facilities();
171 			break;
172 		}
173 	}
174 }
175 
176 static void modify_fac_list(char *str)
177 {
178 	unsigned long val, endval;
179 	char *endp;
180 	bool clear;
181 
182 	while (*str) {
183 		clear = false;
184 		if (*str == '!') {
185 			clear = true;
186 			str++;
187 		}
188 		val = simple_strtoull(str, &endp, 0);
189 		if (str == endp)
190 			break;
191 		str = endp;
192 		if (*str == '-') {
193 			str++;
194 			endval = simple_strtoull(str, &endp, 0);
195 			if (str == endp)
196 				break;
197 			str = endp;
198 			while (val <= endval) {
199 				modify_facility(val, clear);
200 				val++;
201 			}
202 		} else {
203 			modify_facility(val, clear);
204 		}
205 		if (*str != ',')
206 			break;
207 		str++;
208 	}
209 	check_cleared_facilities();
210 }
211 
212 static char command_line_buf[COMMAND_LINE_SIZE] __section(.data);
213 void parse_boot_command_line(void)
214 {
215 	char *param, *val;
216 	bool enabled;
217 	char *args;
218 	int rc;
219 
220 	kaslr_enabled = IS_ENABLED(CONFIG_RANDOMIZE_BASE);
221 	args = strcpy(command_line_buf, early_command_line);
222 	while (*args) {
223 		args = next_arg(args, &param, &val);
224 
225 		if (!strcmp(param, "mem") && val) {
226 			memory_end = round_down(memparse(val, NULL), PAGE_SIZE);
227 			memory_end_set = 1;
228 		}
229 
230 		if (!strcmp(param, "vmalloc") && val)
231 			vmalloc_size = round_up(memparse(val, NULL), PAGE_SIZE);
232 
233 		if (!strcmp(param, "dfltcc")) {
234 			if (!strcmp(val, "off"))
235 				zlib_dfltcc_support = ZLIB_DFLTCC_DISABLED;
236 			else if (!strcmp(val, "on"))
237 				zlib_dfltcc_support = ZLIB_DFLTCC_FULL;
238 			else if (!strcmp(val, "def_only"))
239 				zlib_dfltcc_support = ZLIB_DFLTCC_DEFLATE_ONLY;
240 			else if (!strcmp(val, "inf_only"))
241 				zlib_dfltcc_support = ZLIB_DFLTCC_INFLATE_ONLY;
242 			else if (!strcmp(val, "always"))
243 				zlib_dfltcc_support = ZLIB_DFLTCC_FULL_DEBUG;
244 		}
245 
246 		if (!strcmp(param, "noexec")) {
247 			rc = kstrtobool(val, &enabled);
248 			if (!rc && !enabled)
249 				noexec_disabled = 1;
250 		}
251 
252 		if (!strcmp(param, "facilities") && val)
253 			modify_fac_list(val);
254 
255 		if (!strcmp(param, "nokaslr"))
256 			kaslr_enabled = 0;
257 	}
258 }
259 
260 void setup_memory_end(void)
261 {
262 #ifdef CONFIG_CRASH_DUMP
263 	if (OLDMEM_BASE) {
264 		kaslr_enabled = 0;
265 	} else if (ipl_block_valid &&
266 		   ipl_block.pb0_hdr.pbt == IPL_PBT_FCP &&
267 		   ipl_block.fcp.opt == IPL_PB0_FCP_OPT_DUMP) {
268 		kaslr_enabled = 0;
269 		if (!sclp_early_get_hsa_size(&memory_end) && memory_end)
270 			memory_end_set = 1;
271 	}
272 #endif
273 }
274