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