xref: /openbmc/linux/arch/s390/boot/ipl_parm.c (revision 113094f7)
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/uv.h>
11 #include "boot.h"
12 
13 char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
14 struct ipl_parameter_block __bootdata_preserved(ipl_block);
15 int __bootdata_preserved(ipl_block_valid);
16 
17 unsigned long __bootdata(memory_end);
18 int __bootdata(memory_end_set);
19 int __bootdata(noexec_disabled);
20 
21 int kaslr_enabled __section(.data);
22 
23 static inline int __diag308(unsigned long subcode, void *addr)
24 {
25 	register unsigned long _addr asm("0") = (unsigned long)addr;
26 	register unsigned long _rc asm("1") = 0;
27 	unsigned long reg1, reg2;
28 	psw_t old = S390_lowcore.program_new_psw;
29 
30 	asm volatile(
31 		"	epsw	%0,%1\n"
32 		"	st	%0,%[psw_pgm]\n"
33 		"	st	%1,%[psw_pgm]+4\n"
34 		"	larl	%0,1f\n"
35 		"	stg	%0,%[psw_pgm]+8\n"
36 		"	diag	%[addr],%[subcode],0x308\n"
37 		"1:	nopr	%%r7\n"
38 		: "=&d" (reg1), "=&a" (reg2),
39 		  [psw_pgm] "=Q" (S390_lowcore.program_new_psw),
40 		  [addr] "+d" (_addr), "+d" (_rc)
41 		: [subcode] "d" (subcode)
42 		: "cc", "memory");
43 	S390_lowcore.program_new_psw = old;
44 	return _rc;
45 }
46 
47 void store_ipl_parmblock(void)
48 {
49 	int rc;
50 
51 	uv_set_shared(__pa(&ipl_block));
52 	rc = __diag308(DIAG308_STORE, &ipl_block);
53 	uv_remove_shared(__pa(&ipl_block));
54 	if (rc == DIAG308_RC_OK &&
55 	    ipl_block.hdr.version <= IPL_MAX_SUPPORTED_VERSION)
56 		ipl_block_valid = 1;
57 }
58 
59 static size_t scpdata_length(const u8 *buf, size_t count)
60 {
61 	while (count) {
62 		if (buf[count - 1] != '\0' && buf[count - 1] != ' ')
63 			break;
64 		count--;
65 	}
66 	return count;
67 }
68 
69 static size_t ipl_block_get_ascii_scpdata(char *dest, size_t size,
70 					  const struct ipl_parameter_block *ipb)
71 {
72 	size_t count;
73 	size_t i;
74 	int has_lowercase;
75 
76 	count = min(size - 1, scpdata_length(ipb->fcp.scp_data,
77 					     ipb->fcp.scp_data_len));
78 	if (!count)
79 		goto out;
80 
81 	has_lowercase = 0;
82 	for (i = 0; i < count; i++) {
83 		if (!isascii(ipb->fcp.scp_data[i])) {
84 			count = 0;
85 			goto out;
86 		}
87 		if (!has_lowercase && islower(ipb->fcp.scp_data[i]))
88 			has_lowercase = 1;
89 	}
90 
91 	if (has_lowercase)
92 		memcpy(dest, ipb->fcp.scp_data, count);
93 	else
94 		for (i = 0; i < count; i++)
95 			dest[i] = tolower(ipb->fcp.scp_data[i]);
96 out:
97 	dest[count] = '\0';
98 	return count;
99 }
100 
101 static void append_ipl_block_parm(void)
102 {
103 	char *parm, *delim;
104 	size_t len, rc = 0;
105 
106 	len = strlen(early_command_line);
107 
108 	delim = early_command_line + len;    /* '\0' character position */
109 	parm = early_command_line + len + 1; /* append right after '\0' */
110 
111 	switch (ipl_block.pb0_hdr.pbt) {
112 	case IPL_PBT_CCW:
113 		rc = ipl_block_get_ascii_vmparm(
114 			parm, COMMAND_LINE_SIZE - len - 1, &ipl_block);
115 		break;
116 	case IPL_PBT_FCP:
117 		rc = ipl_block_get_ascii_scpdata(
118 			parm, COMMAND_LINE_SIZE - len - 1, &ipl_block);
119 		break;
120 	}
121 	if (rc) {
122 		if (*parm == '=')
123 			memmove(early_command_line, parm + 1, rc);
124 		else
125 			*delim = ' '; /* replace '\0' with space */
126 	}
127 }
128 
129 static inline int has_ebcdic_char(const char *str)
130 {
131 	int i;
132 
133 	for (i = 0; str[i]; i++)
134 		if (str[i] & 0x80)
135 			return 1;
136 	return 0;
137 }
138 
139 void setup_boot_command_line(void)
140 {
141 	COMMAND_LINE[ARCH_COMMAND_LINE_SIZE - 1] = 0;
142 	/* convert arch command line to ascii if necessary */
143 	if (has_ebcdic_char(COMMAND_LINE))
144 		EBCASC(COMMAND_LINE, ARCH_COMMAND_LINE_SIZE);
145 	/* copy arch command line */
146 	strcpy(early_command_line, strim(COMMAND_LINE));
147 
148 	/* append IPL PARM data to the boot command line */
149 	if (!is_prot_virt_guest() && ipl_block_valid)
150 		append_ipl_block_parm();
151 }
152 
153 static void modify_facility(unsigned long nr, bool clear)
154 {
155 	if (clear)
156 		__clear_facility(nr, S390_lowcore.stfle_fac_list);
157 	else
158 		__set_facility(nr, S390_lowcore.stfle_fac_list);
159 }
160 
161 static void check_cleared_facilities(void)
162 {
163 	unsigned long als[] = { FACILITIES_ALS };
164 	int i;
165 
166 	for (i = 0; i < ARRAY_SIZE(als); i++) {
167 		if ((S390_lowcore.stfle_fac_list[i] & als[i]) != als[i]) {
168 			sclp_early_printk("Warning: The Linux kernel requires facilities cleared via command line option\n");
169 			print_missing_facilities();
170 			break;
171 		}
172 	}
173 }
174 
175 static void modify_fac_list(char *str)
176 {
177 	unsigned long val, endval;
178 	char *endp;
179 	bool clear;
180 
181 	while (*str) {
182 		clear = false;
183 		if (*str == '!') {
184 			clear = true;
185 			str++;
186 		}
187 		val = simple_strtoull(str, &endp, 0);
188 		if (str == endp)
189 			break;
190 		str = endp;
191 		if (*str == '-') {
192 			str++;
193 			endval = simple_strtoull(str, &endp, 0);
194 			if (str == endp)
195 				break;
196 			str = endp;
197 			while (val <= endval) {
198 				modify_facility(val, clear);
199 				val++;
200 			}
201 		} else {
202 			modify_facility(val, clear);
203 		}
204 		if (*str != ',')
205 			break;
206 		str++;
207 	}
208 	check_cleared_facilities();
209 }
210 
211 static char command_line_buf[COMMAND_LINE_SIZE] __section(.data);
212 void parse_boot_command_line(void)
213 {
214 	char *param, *val;
215 	bool enabled;
216 	char *args;
217 	int rc;
218 
219 	kaslr_enabled = IS_ENABLED(CONFIG_RANDOMIZE_BASE);
220 	args = strcpy(command_line_buf, early_command_line);
221 	while (*args) {
222 		args = next_arg(args, &param, &val);
223 
224 		if (!strcmp(param, "mem")) {
225 			memory_end = memparse(val, NULL);
226 			memory_end_set = 1;
227 		}
228 
229 		if (!strcmp(param, "noexec")) {
230 			rc = kstrtobool(val, &enabled);
231 			if (!rc && !enabled)
232 				noexec_disabled = 1;
233 		}
234 
235 		if (!strcmp(param, "facilities"))
236 			modify_fac_list(val);
237 
238 		if (!strcmp(param, "nokaslr"))
239 			kaslr_enabled = 0;
240 	}
241 }
242 
243 void setup_memory_end(void)
244 {
245 #ifdef CONFIG_CRASH_DUMP
246 	if (OLDMEM_BASE) {
247 		kaslr_enabled = 0;
248 	} else if (ipl_block_valid &&
249 		   ipl_block.pb0_hdr.pbt == IPL_PBT_FCP &&
250 		   ipl_block.fcp.opt == IPL_PB0_FCP_OPT_DUMP) {
251 		kaslr_enabled = 0;
252 		if (!sclp_early_get_hsa_size(&memory_end) && memory_end)
253 			memory_end_set = 1;
254 	}
255 #endif
256 }
257