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];
 22int __bootdata(noexec_disabled);
 23
 24unsigned int __bootdata_preserved(zlib_dfltcc_support) = ZLIB_DFLTCC_FULL;
 25struct ipl_parameter_block __bootdata_preserved(ipl_block);
 26int __bootdata_preserved(ipl_block_valid);
 27
 28unsigned long vmalloc_size = VMALLOC_DEFAULT_SIZE;
 29unsigned long memory_limit;
 30int vmalloc_size_set;
 31int kaslr_enabled;
 32
 33static inline int __diag308(unsigned long subcode, void *addr)
 34{
 35	unsigned long reg1, reg2;
 36	union register_pair r1;
 37	psw_t old;
 38
 39	r1.even = (unsigned long) addr;
 40	r1.odd	= 0;
 41	asm volatile(
 42		"	mvc	0(16,%[psw_old]),0(%[psw_pgm])\n"
 43		"	epsw	%[reg1],%[reg2]\n"
 44		"	st	%[reg1],0(%[psw_pgm])\n"
 45		"	st	%[reg2],4(%[psw_pgm])\n"
 46		"	larl	%[reg1],1f\n"
 47		"	stg	%[reg1],8(%[psw_pgm])\n"
 48		"	diag	%[r1],%[subcode],0x308\n"
 49		"1:	mvc	0(16,%[psw_pgm]),0(%[psw_old])\n"
 50		: [r1] "+&d" (r1.pair),
 51		  [reg1] "=&d" (reg1),
 52		  [reg2] "=&a" (reg2),
 53		  "+Q" (S390_lowcore.program_new_psw),
 54		  "=Q" (old)
 55		: [subcode] "d" (subcode),
 56		  [psw_old] "a" (&old),
 57		  [psw_pgm] "a" (&S390_lowcore.program_new_psw)
 58		: "cc", "memory");
 59	return r1.odd;
 60}
 61
 62void store_ipl_parmblock(void)
 63{
 64	int rc;
 65
 66	rc = __diag308(DIAG308_STORE, &ipl_block);
 67	if (rc == DIAG308_RC_OK &&
 68	    ipl_block.hdr.version <= IPL_MAX_SUPPORTED_VERSION)
 69		ipl_block_valid = 1;
 70}
 71
 72bool is_ipl_block_dump(void)
 73{
 74	if (ipl_block.pb0_hdr.pbt == IPL_PBT_FCP &&
 75	    ipl_block.fcp.opt == IPL_PB0_FCP_OPT_DUMP)
 76		return true;
 77	if (ipl_block.pb0_hdr.pbt == IPL_PBT_NVME &&
 78	    ipl_block.nvme.opt == IPL_PB0_NVME_OPT_DUMP)
 79		return true;
 80	if (ipl_block.pb0_hdr.pbt == IPL_PBT_ECKD &&
 81	    ipl_block.eckd.opt == IPL_PB0_ECKD_OPT_DUMP)
 82		return true;
 83	return false;
 84}
 85
 86static size_t scpdata_length(const u8 *buf, size_t count)
 87{
 88	while (count) {
 89		if (buf[count - 1] != '\0' && buf[count - 1] != ' ')
 90			break;
 91		count--;
 92	}
 93	return count;
 94}
 95
 96static size_t ipl_block_get_ascii_scpdata(char *dest, size_t size,
 97					  const struct ipl_parameter_block *ipb)
 98{
 99	const __u8 *scp_data;
100	__u32 scp_data_len;
101	int has_lowercase;
102	size_t count = 0;
103	size_t i;
104
105	switch (ipb->pb0_hdr.pbt) {
106	case IPL_PBT_FCP:
107		scp_data_len = ipb->fcp.scp_data_len;
108		scp_data = ipb->fcp.scp_data;
109		break;
110	case IPL_PBT_NVME:
111		scp_data_len = ipb->nvme.scp_data_len;
112		scp_data = ipb->nvme.scp_data;
113		break;
114	case IPL_PBT_ECKD:
115		scp_data_len = ipb->eckd.scp_data_len;
116		scp_data = ipb->eckd.scp_data;
117		break;
118
119	default:
120		goto out;
121	}
122
123	count = min(size - 1, scpdata_length(scp_data, scp_data_len));
124	if (!count)
125		goto out;
126
127	has_lowercase = 0;
128	for (i = 0; i < count; i++) {
129		if (!isascii(scp_data[i])) {
130			count = 0;
131			goto out;
132		}
133		if (!has_lowercase && islower(scp_data[i]))
134			has_lowercase = 1;
135	}
136
137	if (has_lowercase)
138		memcpy(dest, scp_data, count);
139	else
140		for (i = 0; i < count; i++)
141			dest[i] = tolower(scp_data[i]);
142out:
143	dest[count] = '\0';
144	return count;
145}
146
147static void append_ipl_block_parm(void)
148{
149	char *parm, *delim;
150	size_t len, rc = 0;
151
152	len = strlen(early_command_line);
153
154	delim = early_command_line + len;    /* '\0' character position */
155	parm = early_command_line + len + 1; /* append right after '\0' */
156
157	switch (ipl_block.pb0_hdr.pbt) {
158	case IPL_PBT_CCW:
159		rc = ipl_block_get_ascii_vmparm(
160			parm, COMMAND_LINE_SIZE - len - 1, &ipl_block);
161		break;
162	case IPL_PBT_FCP:
163	case IPL_PBT_NVME:
164	case IPL_PBT_ECKD:
165		rc = ipl_block_get_ascii_scpdata(
166			parm, COMMAND_LINE_SIZE - len - 1, &ipl_block);
167		break;
168	}
169	if (rc) {
170		if (*parm == '=')
171			memmove(early_command_line, parm + 1, rc);
172		else
173			*delim = ' '; /* replace '\0' with space */
174	}
175}
176
177static inline int has_ebcdic_char(const char *str)
178{
179	int i;
180
181	for (i = 0; str[i]; i++)
182		if (str[i] & 0x80)
183			return 1;
184	return 0;
185}
186
187void setup_boot_command_line(void)
188{
189	parmarea.command_line[COMMAND_LINE_SIZE - 1] = 0;
190	/* convert arch command line to ascii if necessary */
191	if (has_ebcdic_char(parmarea.command_line))
192		EBCASC(parmarea.command_line, COMMAND_LINE_SIZE);
193	/* copy arch command line */
194	strcpy(early_command_line, strim(parmarea.command_line));
195
196	/* append IPL PARM data to the boot command line */
197	if (!is_prot_virt_guest() && ipl_block_valid)
198		append_ipl_block_parm();
199}
200
201static void modify_facility(unsigned long nr, bool clear)
202{
203	if (clear)
204		__clear_facility(nr, stfle_fac_list);
205	else
206		__set_facility(nr, stfle_fac_list);
207}
208
209static void check_cleared_facilities(void)
210{
211	unsigned long als[] = { FACILITIES_ALS };
212	int i;
213
214	for (i = 0; i < ARRAY_SIZE(als); i++) {
215		if ((stfle_fac_list[i] & als[i]) != als[i]) {
216			sclp_early_printk("Warning: The Linux kernel requires facilities cleared via command line option\n");
217			print_missing_facilities();
218			break;
219		}
220	}
221}
222
223static void modify_fac_list(char *str)
224{
225	unsigned long val, endval;
226	char *endp;
227	bool clear;
228
229	while (*str) {
230		clear = false;
231		if (*str == '!') {
232			clear = true;
233			str++;
234		}
235		val = simple_strtoull(str, &endp, 0);
236		if (str == endp)
237			break;
238		str = endp;
239		if (*str == '-') {
240			str++;
241			endval = simple_strtoull(str, &endp, 0);
242			if (str == endp)
243				break;
244			str = endp;
245			while (val <= endval) {
246				modify_facility(val, clear);
247				val++;
248			}
249		} else {
250			modify_facility(val, clear);
251		}
252		if (*str != ',')
253			break;
254		str++;
255	}
256	check_cleared_facilities();
257}
258
259static char command_line_buf[COMMAND_LINE_SIZE];
260void parse_boot_command_line(void)
261{
262	char *param, *val;
263	bool enabled;
264	char *args;
265	int rc;
266
267	kaslr_enabled = IS_ENABLED(CONFIG_RANDOMIZE_BASE);
268	args = strcpy(command_line_buf, early_command_line);
269	while (*args) {
270		args = next_arg(args, &param, &val);
271
272		if (!strcmp(param, "mem") && val)
273			memory_limit = round_down(memparse(val, NULL), PAGE_SIZE);
274
275		if (!strcmp(param, "vmalloc") && val) {
276			vmalloc_size = round_up(memparse(val, NULL), PAGE_SIZE);
277			vmalloc_size_set = 1;
278		}
279
280		if (!strcmp(param, "dfltcc") && val) {
281			if (!strcmp(val, "off"))
282				zlib_dfltcc_support = ZLIB_DFLTCC_DISABLED;
283			else if (!strcmp(val, "on"))
284				zlib_dfltcc_support = ZLIB_DFLTCC_FULL;
285			else if (!strcmp(val, "def_only"))
286				zlib_dfltcc_support = ZLIB_DFLTCC_DEFLATE_ONLY;
287			else if (!strcmp(val, "inf_only"))
288				zlib_dfltcc_support = ZLIB_DFLTCC_INFLATE_ONLY;
289			else if (!strcmp(val, "always"))
290				zlib_dfltcc_support = ZLIB_DFLTCC_FULL_DEBUG;
291		}
292
293		if (!strcmp(param, "noexec")) {
294			rc = kstrtobool(val, &enabled);
295			if (!rc && !enabled)
296				noexec_disabled = 1;
297		}
298
299		if (!strcmp(param, "facilities") && val)
300			modify_fac_list(val);
301
302		if (!strcmp(param, "nokaslr"))
303			kaslr_enabled = 0;
304
305#if IS_ENABLED(CONFIG_KVM)
306		if (!strcmp(param, "prot_virt")) {
307			rc = kstrtobool(val, &enabled);
308			if (!rc && enabled)
309				prot_virt_host = 1;
310		}
311#endif
312	}
313}