xref: /kernel/linux/linux-6.6/arch/s390/boot/ipl_parm.c (revision 62306a36)
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/setup.h>
12#include <asm/uv.h>
13#include "boot.h"
14
15struct parmarea parmarea __section(".parmarea") = {
16	.kernel_version		= (unsigned long)kernel_version,
17	.max_command_line_size	= COMMAND_LINE_SIZE,
18	.command_line		= "root=/dev/ram0 ro",
19};
20
21char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
22
23unsigned int __bootdata_preserved(zlib_dfltcc_support) = ZLIB_DFLTCC_FULL;
24struct ipl_parameter_block __bootdata_preserved(ipl_block);
25int __bootdata_preserved(ipl_block_valid);
26int __bootdata_preserved(__kaslr_enabled);
27
28unsigned long vmalloc_size = VMALLOC_DEFAULT_SIZE;
29unsigned long memory_limit;
30int vmalloc_size_set;
31
32static inline int __diag308(unsigned long subcode, void *addr)
33{
34	unsigned long reg1, reg2;
35	union register_pair r1;
36	psw_t old;
37
38	r1.even = (unsigned long) addr;
39	r1.odd	= 0;
40	asm volatile(
41		"	mvc	0(16,%[psw_old]),0(%[psw_pgm])\n"
42		"	epsw	%[reg1],%[reg2]\n"
43		"	st	%[reg1],0(%[psw_pgm])\n"
44		"	st	%[reg2],4(%[psw_pgm])\n"
45		"	larl	%[reg1],1f\n"
46		"	stg	%[reg1],8(%[psw_pgm])\n"
47		"	diag	%[r1],%[subcode],0x308\n"
48		"1:	mvc	0(16,%[psw_pgm]),0(%[psw_old])\n"
49		: [r1] "+&d" (r1.pair),
50		  [reg1] "=&d" (reg1),
51		  [reg2] "=&a" (reg2),
52		  "+Q" (S390_lowcore.program_new_psw),
53		  "=Q" (old)
54		: [subcode] "d" (subcode),
55		  [psw_old] "a" (&old),
56		  [psw_pgm] "a" (&S390_lowcore.program_new_psw)
57		: "cc", "memory");
58	return r1.odd;
59}
60
61void store_ipl_parmblock(void)
62{
63	int rc;
64
65	rc = __diag308(DIAG308_STORE, &ipl_block);
66	if (rc == DIAG308_RC_OK &&
67	    ipl_block.hdr.version <= IPL_MAX_SUPPORTED_VERSION)
68		ipl_block_valid = 1;
69}
70
71bool is_ipl_block_dump(void)
72{
73	if (ipl_block.pb0_hdr.pbt == IPL_PBT_FCP &&
74	    ipl_block.fcp.opt == IPL_PB0_FCP_OPT_DUMP)
75		return true;
76	if (ipl_block.pb0_hdr.pbt == IPL_PBT_NVME &&
77	    ipl_block.nvme.opt == IPL_PB0_NVME_OPT_DUMP)
78		return true;
79	if (ipl_block.pb0_hdr.pbt == IPL_PBT_ECKD &&
80	    ipl_block.eckd.opt == IPL_PB0_ECKD_OPT_DUMP)
81		return true;
82	return false;
83}
84
85static size_t scpdata_length(const u8 *buf, size_t count)
86{
87	while (count) {
88		if (buf[count - 1] != '\0' && buf[count - 1] != ' ')
89			break;
90		count--;
91	}
92	return count;
93}
94
95static size_t ipl_block_get_ascii_scpdata(char *dest, size_t size,
96					  const struct ipl_parameter_block *ipb)
97{
98	const __u8 *scp_data;
99	__u32 scp_data_len;
100	int has_lowercase;
101	size_t count = 0;
102	size_t i;
103
104	switch (ipb->pb0_hdr.pbt) {
105	case IPL_PBT_FCP:
106		scp_data_len = ipb->fcp.scp_data_len;
107		scp_data = ipb->fcp.scp_data;
108		break;
109	case IPL_PBT_NVME:
110		scp_data_len = ipb->nvme.scp_data_len;
111		scp_data = ipb->nvme.scp_data;
112		break;
113	case IPL_PBT_ECKD:
114		scp_data_len = ipb->eckd.scp_data_len;
115		scp_data = ipb->eckd.scp_data;
116		break;
117
118	default:
119		goto out;
120	}
121
122	count = min(size - 1, scpdata_length(scp_data, scp_data_len));
123	if (!count)
124		goto out;
125
126	has_lowercase = 0;
127	for (i = 0; i < count; i++) {
128		if (!isascii(scp_data[i])) {
129			count = 0;
130			goto out;
131		}
132		if (!has_lowercase && islower(scp_data[i]))
133			has_lowercase = 1;
134	}
135
136	if (has_lowercase)
137		memcpy(dest, scp_data, count);
138	else
139		for (i = 0; i < count; i++)
140			dest[i] = tolower(scp_data[i]);
141out:
142	dest[count] = '\0';
143	return count;
144}
145
146static void append_ipl_block_parm(void)
147{
148	char *parm, *delim;
149	size_t len, rc = 0;
150
151	len = strlen(early_command_line);
152
153	delim = early_command_line + len;    /* '\0' character position */
154	parm = early_command_line + len + 1; /* append right after '\0' */
155
156	switch (ipl_block.pb0_hdr.pbt) {
157	case IPL_PBT_CCW:
158		rc = ipl_block_get_ascii_vmparm(
159			parm, COMMAND_LINE_SIZE - len - 1, &ipl_block);
160		break;
161	case IPL_PBT_FCP:
162	case IPL_PBT_NVME:
163	case IPL_PBT_ECKD:
164		rc = ipl_block_get_ascii_scpdata(
165			parm, COMMAND_LINE_SIZE - len - 1, &ipl_block);
166		break;
167	}
168	if (rc) {
169		if (*parm == '=')
170			memmove(early_command_line, parm + 1, rc);
171		else
172			*delim = ' '; /* replace '\0' with space */
173	}
174}
175
176static inline int has_ebcdic_char(const char *str)
177{
178	int i;
179
180	for (i = 0; str[i]; i++)
181		if (str[i] & 0x80)
182			return 1;
183	return 0;
184}
185
186void setup_boot_command_line(void)
187{
188	parmarea.command_line[COMMAND_LINE_SIZE - 1] = 0;
189	/* convert arch command line to ascii if necessary */
190	if (has_ebcdic_char(parmarea.command_line))
191		EBCASC(parmarea.command_line, COMMAND_LINE_SIZE);
192	/* copy arch command line */
193	strcpy(early_command_line, strim(parmarea.command_line));
194
195	/* append IPL PARM data to the boot command line */
196	if (!is_prot_virt_guest() && ipl_block_valid)
197		append_ipl_block_parm();
198}
199
200static void modify_facility(unsigned long nr, bool clear)
201{
202	if (clear)
203		__clear_facility(nr, stfle_fac_list);
204	else
205		__set_facility(nr, stfle_fac_list);
206}
207
208static void check_cleared_facilities(void)
209{
210	unsigned long als[] = { FACILITIES_ALS };
211	int i;
212
213	for (i = 0; i < ARRAY_SIZE(als); i++) {
214		if ((stfle_fac_list[i] & als[i]) != als[i]) {
215			sclp_early_printk("Warning: The Linux kernel requires facilities cleared via command line option\n");
216			print_missing_facilities();
217			break;
218		}
219	}
220}
221
222static void modify_fac_list(char *str)
223{
224	unsigned long val, endval;
225	char *endp;
226	bool clear;
227
228	while (*str) {
229		clear = false;
230		if (*str == '!') {
231			clear = true;
232			str++;
233		}
234		val = simple_strtoull(str, &endp, 0);
235		if (str == endp)
236			break;
237		str = endp;
238		if (*str == '-') {
239			str++;
240			endval = simple_strtoull(str, &endp, 0);
241			if (str == endp)
242				break;
243			str = endp;
244			while (val <= endval) {
245				modify_facility(val, clear);
246				val++;
247			}
248		} else {
249			modify_facility(val, clear);
250		}
251		if (*str != ',')
252			break;
253		str++;
254	}
255	check_cleared_facilities();
256}
257
258static char command_line_buf[COMMAND_LINE_SIZE];
259void parse_boot_command_line(void)
260{
261	char *param, *val;
262	bool enabled;
263	char *args;
264	int rc;
265
266	__kaslr_enabled = IS_ENABLED(CONFIG_RANDOMIZE_BASE);
267	args = strcpy(command_line_buf, early_command_line);
268	while (*args) {
269		args = next_arg(args, &param, &val);
270
271		if (!strcmp(param, "mem") && val)
272			memory_limit = round_down(memparse(val, NULL), PAGE_SIZE);
273
274		if (!strcmp(param, "vmalloc") && val) {
275			vmalloc_size = round_up(memparse(val, NULL), _SEGMENT_SIZE);
276			vmalloc_size_set = 1;
277		}
278
279		if (!strcmp(param, "dfltcc") && val) {
280			if (!strcmp(val, "off"))
281				zlib_dfltcc_support = ZLIB_DFLTCC_DISABLED;
282			else if (!strcmp(val, "on"))
283				zlib_dfltcc_support = ZLIB_DFLTCC_FULL;
284			else if (!strcmp(val, "def_only"))
285				zlib_dfltcc_support = ZLIB_DFLTCC_DEFLATE_ONLY;
286			else if (!strcmp(val, "inf_only"))
287				zlib_dfltcc_support = ZLIB_DFLTCC_INFLATE_ONLY;
288			else if (!strcmp(val, "always"))
289				zlib_dfltcc_support = ZLIB_DFLTCC_FULL_DEBUG;
290		}
291
292		if (!strcmp(param, "facilities") && val)
293			modify_fac_list(val);
294
295		if (!strcmp(param, "nokaslr"))
296			__kaslr_enabled = 0;
297
298#if IS_ENABLED(CONFIG_KVM)
299		if (!strcmp(param, "prot_virt")) {
300			rc = kstrtobool(val, &enabled);
301			if (!rc && enabled)
302				prot_virt_host = 1;
303		}
304#endif
305	}
306}
307