xref: /openbmc/linux/drivers/s390/char/sclp_early.c (revision 3e26a691)
1 /*
2  * SCLP early driver
3  *
4  * Copyright IBM Corp. 2013
5  */
6 
7 #define KMSG_COMPONENT "sclp_early"
8 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
9 
10 #include <linux/errno.h>
11 #include <asm/ctl_reg.h>
12 #include <asm/sclp.h>
13 #include <asm/ipl.h>
14 #include "sclp_sdias.h"
15 #include "sclp.h"
16 
17 #define SCLP_CMDW_READ_SCP_INFO		0x00020001
18 #define SCLP_CMDW_READ_SCP_INFO_FORCED	0x00120001
19 
20 struct read_info_sccb {
21 	struct	sccb_header header;	/* 0-7 */
22 	u16	rnmax;			/* 8-9 */
23 	u8	rnsize;			/* 10 */
24 	u8	_pad_11[16 - 11];	/* 11-15 */
25 	u16	ncpurl;			/* 16-17 */
26 	u16	cpuoff;			/* 18-19 */
27 	u8	_pad_20[24 - 20];	/* 20-23 */
28 	u8	loadparm[8];		/* 24-31 */
29 	u8	_pad_32[42 - 32];	/* 32-41 */
30 	u8	fac42;			/* 42 */
31 	u8	fac43;			/* 43 */
32 	u8	_pad_44[48 - 44];	/* 44-47 */
33 	u64	facilities;		/* 48-55 */
34 	u8	_pad_56[66 - 56];	/* 56-65 */
35 	u8	fac66;			/* 66 */
36 	u8	_pad_67[76 - 67];	/* 67-83 */
37 	u32	ibc;			/* 76-79 */
38 	u8	_pad80[84 - 80];	/* 80-83 */
39 	u8	fac84;			/* 84 */
40 	u8	fac85;			/* 85 */
41 	u8	_pad_86[91 - 86];	/* 86-90 */
42 	u8	flags;			/* 91 */
43 	u8	_pad_92[99 - 92];	/* 92-98 */
44 	u8	hamaxpow;		/* 99 */
45 	u32	rnsize2;		/* 100-103 */
46 	u64	rnmax2;			/* 104-111 */
47 	u8	_pad_112[116 - 112];	/* 112-115 */
48 	u8	fac116;			/* 116 */
49 	u8	_pad_117[119 - 117];	/* 117-118 */
50 	u8	fac119;			/* 119 */
51 	u16	hcpua;			/* 120-121 */
52 	u8	_pad_122[4096 - 122];	/* 122-4095 */
53 } __packed __aligned(PAGE_SIZE);
54 
55 static char sccb_early[PAGE_SIZE] __aligned(PAGE_SIZE) __initdata;
56 static struct sclp_ipl_info sclp_ipl_info;
57 
58 struct sclp_info sclp;
59 EXPORT_SYMBOL(sclp);
60 
61 static int __init sclp_cmd_sync_early(sclp_cmdw_t cmd, void *sccb)
62 {
63 	int rc;
64 
65 	__ctl_set_bit(0, 9);
66 	rc = sclp_service_call(cmd, sccb);
67 	if (rc)
68 		goto out;
69 	__load_psw_mask(PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_MASK_EA |
70 			PSW_MASK_BA | PSW_MASK_EXT | PSW_MASK_WAIT);
71 	local_irq_disable();
72 out:
73 	/* Contents of the sccb might have changed. */
74 	barrier();
75 	__ctl_clear_bit(0, 9);
76 	return rc;
77 }
78 
79 static int __init sclp_read_info_early(struct read_info_sccb *sccb)
80 {
81 	int rc, i;
82 	sclp_cmdw_t commands[] = {SCLP_CMDW_READ_SCP_INFO_FORCED,
83 				  SCLP_CMDW_READ_SCP_INFO};
84 
85 	for (i = 0; i < ARRAY_SIZE(commands); i++) {
86 		do {
87 			memset(sccb, 0, sizeof(*sccb));
88 			sccb->header.length = sizeof(*sccb);
89 			sccb->header.function_code = 0x80;
90 			sccb->header.control_mask[2] = 0x80;
91 			rc = sclp_cmd_sync_early(commands[i], sccb);
92 		} while (rc == -EBUSY);
93 
94 		if (rc)
95 			break;
96 		if (sccb->header.response_code == 0x10)
97 			return 0;
98 		if (sccb->header.response_code != 0x1f0)
99 			break;
100 	}
101 	return -EIO;
102 }
103 
104 static void __init sclp_facilities_detect(struct read_info_sccb *sccb)
105 {
106 	struct sclp_core_entry *cpue;
107 	u16 boot_cpu_address, cpu;
108 
109 	if (sclp_read_info_early(sccb))
110 		return;
111 
112 	sclp.facilities = sccb->facilities;
113 	sclp.has_sprp = !!(sccb->fac84 & 0x02);
114 	sclp.has_core_type = !!(sccb->fac84 & 0x01);
115 	sclp.has_esca = !!(sccb->fac116 & 0x08);
116 	sclp.has_hvs = !!(sccb->fac119 & 0x80);
117 	if (sccb->fac85 & 0x02)
118 		S390_lowcore.machine_flags |= MACHINE_FLAG_ESOP;
119 	sclp.rnmax = sccb->rnmax ? sccb->rnmax : sccb->rnmax2;
120 	sclp.rzm = sccb->rnsize ? sccb->rnsize : sccb->rnsize2;
121 	sclp.rzm <<= 20;
122 	sclp.ibc = sccb->ibc;
123 
124 	if (sccb->hamaxpow && sccb->hamaxpow < 64)
125 		sclp.hamax = (1UL << sccb->hamaxpow) - 1;
126 	else
127 		sclp.hamax = U64_MAX;
128 
129 	if (!sccb->hcpua) {
130 		if (MACHINE_IS_VM)
131 			sclp.max_cores = 64;
132 		else
133 			sclp.max_cores = sccb->ncpurl;
134 	} else {
135 		sclp.max_cores = sccb->hcpua + 1;
136 	}
137 
138 	boot_cpu_address = stap();
139 	cpue = (void *)sccb + sccb->cpuoff;
140 	for (cpu = 0; cpu < sccb->ncpurl; cpue++, cpu++) {
141 		if (boot_cpu_address != cpue->core_id)
142 			continue;
143 		sclp.has_siif = cpue->siif;
144 		sclp.has_sigpif = cpue->sigpif;
145 		sclp.has_sief2 = cpue->sief2;
146 		break;
147 	}
148 
149 	/* Save IPL information */
150 	sclp_ipl_info.is_valid = 1;
151 	if (sccb->flags & 0x2)
152 		sclp_ipl_info.has_dump = 1;
153 	memcpy(&sclp_ipl_info.loadparm, &sccb->loadparm, LOADPARM_LEN);
154 
155 	sclp.mtid = (sccb->fac42 & 0x80) ? (sccb->fac42 & 31) : 0;
156 	sclp.mtid_cp = (sccb->fac42 & 0x80) ? (sccb->fac43 & 31) : 0;
157 	sclp.mtid_prev = (sccb->fac42 & 0x80) ? (sccb->fac66 & 31) : 0;
158 }
159 
160 /*
161  * This function will be called after sclp_facilities_detect(), which gets
162  * called from early.c code. The sclp_facilities_detect() function retrieves
163  * and saves the IPL information.
164  */
165 void __init sclp_get_ipl_info(struct sclp_ipl_info *info)
166 {
167 	*info = sclp_ipl_info;
168 }
169 
170 static int __init sclp_cmd_early(sclp_cmdw_t cmd, void *sccb)
171 {
172 	int rc;
173 
174 	do {
175 		rc = sclp_cmd_sync_early(cmd, sccb);
176 	} while (rc == -EBUSY);
177 
178 	if (rc)
179 		return -EIO;
180 	if (((struct sccb_header *) sccb)->response_code != 0x0020)
181 		return -EIO;
182 	return 0;
183 }
184 
185 static void __init sccb_init_eq_size(struct sdias_sccb *sccb)
186 {
187 	memset(sccb, 0, sizeof(*sccb));
188 
189 	sccb->hdr.length = sizeof(*sccb);
190 	sccb->evbuf.hdr.length = sizeof(struct sdias_evbuf);
191 	sccb->evbuf.hdr.type = EVTYP_SDIAS;
192 	sccb->evbuf.event_qual = SDIAS_EQ_SIZE;
193 	sccb->evbuf.data_id = SDIAS_DI_FCP_DUMP;
194 	sccb->evbuf.event_id = 4712;
195 	sccb->evbuf.dbs = 1;
196 }
197 
198 static int __init sclp_set_event_mask(struct init_sccb *sccb,
199 				      unsigned long receive_mask,
200 				      unsigned long send_mask)
201 {
202 	memset(sccb, 0, sizeof(*sccb));
203 	sccb->header.length = sizeof(*sccb);
204 	sccb->mask_length = sizeof(sccb_mask_t);
205 	sccb->receive_mask = receive_mask;
206 	sccb->send_mask = send_mask;
207 	return sclp_cmd_early(SCLP_CMDW_WRITE_EVENT_MASK, sccb);
208 }
209 
210 static long __init sclp_hsa_size_init(struct sdias_sccb *sccb)
211 {
212 	sccb_init_eq_size(sccb);
213 	if (sclp_cmd_early(SCLP_CMDW_WRITE_EVENT_DATA, sccb))
214 		return -EIO;
215 	if (sccb->evbuf.blk_cnt == 0)
216 		return 0;
217 	return (sccb->evbuf.blk_cnt - 1) * PAGE_SIZE;
218 }
219 
220 static long __init sclp_hsa_copy_wait(struct sccb_header *sccb)
221 {
222 	memset(sccb, 0, PAGE_SIZE);
223 	sccb->length = PAGE_SIZE;
224 	if (sclp_cmd_early(SCLP_CMDW_READ_EVENT_DATA, sccb))
225 		return -EIO;
226 	if (((struct sdias_sccb *) sccb)->evbuf.blk_cnt == 0)
227 		return 0;
228 	return (((struct sdias_sccb *) sccb)->evbuf.blk_cnt - 1) * PAGE_SIZE;
229 }
230 
231 static void __init sclp_hsa_size_detect(void *sccb)
232 {
233 	long size;
234 
235 	/* First try synchronous interface (LPAR) */
236 	if (sclp_set_event_mask(sccb, 0, 0x40000010))
237 		return;
238 	size = sclp_hsa_size_init(sccb);
239 	if (size < 0)
240 		return;
241 	if (size != 0)
242 		goto out;
243 	/* Then try asynchronous interface (z/VM) */
244 	if (sclp_set_event_mask(sccb, 0x00000010, 0x40000010))
245 		return;
246 	size = sclp_hsa_size_init(sccb);
247 	if (size < 0)
248 		return;
249 	size = sclp_hsa_copy_wait(sccb);
250 	if (size < 0)
251 		return;
252 out:
253 	sclp.hsa_size = size;
254 }
255 
256 static unsigned int __init sclp_con_check_linemode(struct init_sccb *sccb)
257 {
258 	if (!(sccb->sclp_send_mask & EVTYP_OPCMD_MASK))
259 		return 0;
260 	if (!(sccb->sclp_receive_mask & (EVTYP_MSG_MASK | EVTYP_PMSGCMD_MASK)))
261 		return 0;
262 	return 1;
263 }
264 
265 static void __init sclp_console_detect(struct init_sccb *sccb)
266 {
267 	if (sccb->header.response_code != 0x20)
268 		return;
269 
270 	if (sccb->sclp_send_mask & EVTYP_VT220MSG_MASK)
271 		sclp.has_vt220 = 1;
272 
273 	if (sclp_con_check_linemode(sccb))
274 		sclp.has_linemode = 1;
275 }
276 
277 void __init sclp_early_detect(void)
278 {
279 	void *sccb = &sccb_early;
280 
281 	sclp_facilities_detect(sccb);
282 	sclp_hsa_size_detect(sccb);
283 
284 	/* Turn off SCLP event notifications.  Also save remote masks in the
285 	 * sccb.  These are sufficient to detect sclp console capabilities.
286 	 */
287 	sclp_set_event_mask(sccb, 0, 0);
288 	sclp_console_detect(sccb);
289 }
290