xref: /openbmc/linux/drivers/s390/char/sclp_early.c (revision eb3fcf00)
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[100 - 92];	/* 92-99 */
44 	u32	rnsize2;		/* 100-103 */
45 	u64	rnmax2;			/* 104-111 */
46 	u8	_pad_112[120 - 112];	/* 112-119 */
47 	u16	hcpua;			/* 120-121 */
48 	u8	_pad_122[4096 - 122];	/* 122-4095 */
49 } __packed __aligned(PAGE_SIZE);
50 
51 static char sccb_early[PAGE_SIZE] __aligned(PAGE_SIZE) __initdata;
52 static struct sclp_ipl_info sclp_ipl_info;
53 
54 struct sclp_info sclp;
55 EXPORT_SYMBOL(sclp);
56 
57 static int __init sclp_cmd_sync_early(sclp_cmdw_t cmd, void *sccb)
58 {
59 	int rc;
60 
61 	__ctl_set_bit(0, 9);
62 	rc = sclp_service_call(cmd, sccb);
63 	if (rc)
64 		goto out;
65 	__load_psw_mask(PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_MASK_EA |
66 			PSW_MASK_BA | PSW_MASK_EXT | PSW_MASK_WAIT);
67 	local_irq_disable();
68 out:
69 	/* Contents of the sccb might have changed. */
70 	barrier();
71 	__ctl_clear_bit(0, 9);
72 	return rc;
73 }
74 
75 static int __init sclp_read_info_early(struct read_info_sccb *sccb)
76 {
77 	int rc, i;
78 	sclp_cmdw_t commands[] = {SCLP_CMDW_READ_SCP_INFO_FORCED,
79 				  SCLP_CMDW_READ_SCP_INFO};
80 
81 	for (i = 0; i < ARRAY_SIZE(commands); i++) {
82 		do {
83 			memset(sccb, 0, sizeof(*sccb));
84 			sccb->header.length = sizeof(*sccb);
85 			sccb->header.function_code = 0x80;
86 			sccb->header.control_mask[2] = 0x80;
87 			rc = sclp_cmd_sync_early(commands[i], sccb);
88 		} while (rc == -EBUSY);
89 
90 		if (rc)
91 			break;
92 		if (sccb->header.response_code == 0x10)
93 			return 0;
94 		if (sccb->header.response_code != 0x1f0)
95 			break;
96 	}
97 	return -EIO;
98 }
99 
100 static void __init sclp_facilities_detect(struct read_info_sccb *sccb)
101 {
102 	struct sclp_core_entry *cpue;
103 	u16 boot_cpu_address, cpu;
104 
105 	if (sclp_read_info_early(sccb))
106 		return;
107 
108 	sclp.facilities = sccb->facilities;
109 	sclp.has_sprp = !!(sccb->fac84 & 0x02);
110 	sclp.has_core_type = !!(sccb->fac84 & 0x01);
111 	if (sccb->fac85 & 0x02)
112 		S390_lowcore.machine_flags |= MACHINE_FLAG_ESOP;
113 	sclp.rnmax = sccb->rnmax ? sccb->rnmax : sccb->rnmax2;
114 	sclp.rzm = sccb->rnsize ? sccb->rnsize : sccb->rnsize2;
115 	sclp.rzm <<= 20;
116 	sclp.ibc = sccb->ibc;
117 
118 	if (!sccb->hcpua) {
119 		if (MACHINE_IS_VM)
120 			sclp.max_cores = 64;
121 		else
122 			sclp.max_cores = sccb->ncpurl;
123 	} else {
124 		sclp.max_cores = sccb->hcpua + 1;
125 	}
126 
127 	boot_cpu_address = stap();
128 	cpue = (void *)sccb + sccb->cpuoff;
129 	for (cpu = 0; cpu < sccb->ncpurl; cpue++, cpu++) {
130 		if (boot_cpu_address != cpue->core_id)
131 			continue;
132 		sclp.has_siif = cpue->siif;
133 		sclp.has_sigpif = cpue->sigpif;
134 		break;
135 	}
136 
137 	/* Save IPL information */
138 	sclp_ipl_info.is_valid = 1;
139 	if (sccb->flags & 0x2)
140 		sclp_ipl_info.has_dump = 1;
141 	memcpy(&sclp_ipl_info.loadparm, &sccb->loadparm, LOADPARM_LEN);
142 
143 	sclp.mtid = (sccb->fac42 & 0x80) ? (sccb->fac42 & 31) : 0;
144 	sclp.mtid_cp = (sccb->fac42 & 0x80) ? (sccb->fac43 & 31) : 0;
145 	sclp.mtid_prev = (sccb->fac42 & 0x80) ? (sccb->fac66 & 31) : 0;
146 }
147 
148 /*
149  * This function will be called after sclp_facilities_detect(), which gets
150  * called from early.c code. The sclp_facilities_detect() function retrieves
151  * and saves the IPL information.
152  */
153 void __init sclp_get_ipl_info(struct sclp_ipl_info *info)
154 {
155 	*info = sclp_ipl_info;
156 }
157 
158 static int __init sclp_cmd_early(sclp_cmdw_t cmd, void *sccb)
159 {
160 	int rc;
161 
162 	do {
163 		rc = sclp_cmd_sync_early(cmd, sccb);
164 	} while (rc == -EBUSY);
165 
166 	if (rc)
167 		return -EIO;
168 	if (((struct sccb_header *) sccb)->response_code != 0x0020)
169 		return -EIO;
170 	return 0;
171 }
172 
173 static void __init sccb_init_eq_size(struct sdias_sccb *sccb)
174 {
175 	memset(sccb, 0, sizeof(*sccb));
176 
177 	sccb->hdr.length = sizeof(*sccb);
178 	sccb->evbuf.hdr.length = sizeof(struct sdias_evbuf);
179 	sccb->evbuf.hdr.type = EVTYP_SDIAS;
180 	sccb->evbuf.event_qual = SDIAS_EQ_SIZE;
181 	sccb->evbuf.data_id = SDIAS_DI_FCP_DUMP;
182 	sccb->evbuf.event_id = 4712;
183 	sccb->evbuf.dbs = 1;
184 }
185 
186 static int __init sclp_set_event_mask(struct init_sccb *sccb,
187 				      unsigned long receive_mask,
188 				      unsigned long send_mask)
189 {
190 	memset(sccb, 0, sizeof(*sccb));
191 	sccb->header.length = sizeof(*sccb);
192 	sccb->mask_length = sizeof(sccb_mask_t);
193 	sccb->receive_mask = receive_mask;
194 	sccb->send_mask = send_mask;
195 	return sclp_cmd_early(SCLP_CMDW_WRITE_EVENT_MASK, sccb);
196 }
197 
198 static long __init sclp_hsa_size_init(struct sdias_sccb *sccb)
199 {
200 	sccb_init_eq_size(sccb);
201 	if (sclp_cmd_early(SCLP_CMDW_WRITE_EVENT_DATA, sccb))
202 		return -EIO;
203 	if (sccb->evbuf.blk_cnt == 0)
204 		return 0;
205 	return (sccb->evbuf.blk_cnt - 1) * PAGE_SIZE;
206 }
207 
208 static long __init sclp_hsa_copy_wait(struct sccb_header *sccb)
209 {
210 	memset(sccb, 0, PAGE_SIZE);
211 	sccb->length = PAGE_SIZE;
212 	if (sclp_cmd_early(SCLP_CMDW_READ_EVENT_DATA, sccb))
213 		return -EIO;
214 	if (((struct sdias_sccb *) sccb)->evbuf.blk_cnt == 0)
215 		return 0;
216 	return (((struct sdias_sccb *) sccb)->evbuf.blk_cnt - 1) * PAGE_SIZE;
217 }
218 
219 static void __init sclp_hsa_size_detect(void *sccb)
220 {
221 	long size;
222 
223 	/* First try synchronous interface (LPAR) */
224 	if (sclp_set_event_mask(sccb, 0, 0x40000010))
225 		return;
226 	size = sclp_hsa_size_init(sccb);
227 	if (size < 0)
228 		return;
229 	if (size != 0)
230 		goto out;
231 	/* Then try asynchronous interface (z/VM) */
232 	if (sclp_set_event_mask(sccb, 0x00000010, 0x40000010))
233 		return;
234 	size = sclp_hsa_size_init(sccb);
235 	if (size < 0)
236 		return;
237 	size = sclp_hsa_copy_wait(sccb);
238 	if (size < 0)
239 		return;
240 out:
241 	sclp.hsa_size = size;
242 }
243 
244 static unsigned int __init sclp_con_check_linemode(struct init_sccb *sccb)
245 {
246 	if (!(sccb->sclp_send_mask & EVTYP_OPCMD_MASK))
247 		return 0;
248 	if (!(sccb->sclp_receive_mask & (EVTYP_MSG_MASK | EVTYP_PMSGCMD_MASK)))
249 		return 0;
250 	return 1;
251 }
252 
253 static void __init sclp_console_detect(struct init_sccb *sccb)
254 {
255 	if (sccb->header.response_code != 0x20)
256 		return;
257 
258 	if (sccb->sclp_send_mask & EVTYP_VT220MSG_MASK)
259 		sclp.has_vt220 = 1;
260 
261 	if (sclp_con_check_linemode(sccb))
262 		sclp.has_linemode = 1;
263 }
264 
265 void __init sclp_early_detect(void)
266 {
267 	void *sccb = &sccb_early;
268 
269 	sclp_facilities_detect(sccb);
270 	sclp_hsa_size_detect(sccb);
271 
272 	/* Turn off SCLP event notifications.  Also save remote masks in the
273 	 * sccb.  These are sufficient to detect sclp console capabilities.
274 	 */
275 	sclp_set_event_mask(sccb, 0, 0);
276 	sclp_console_detect(sccb);
277 }
278