xref: /openbmc/linux/drivers/s390/char/sclp_early.c (revision f7018c21)
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 <asm/ctl_reg.h>
11 #include <asm/sclp.h>
12 #include <asm/ipl.h>
13 #include "sclp_sdias.h"
14 #include "sclp.h"
15 
16 #define SCLP_CMDW_READ_SCP_INFO		0x00020001
17 #define SCLP_CMDW_READ_SCP_INFO_FORCED	0x00120001
18 
19 struct read_info_sccb {
20 	struct	sccb_header header;	/* 0-7 */
21 	u16	rnmax;			/* 8-9 */
22 	u8	rnsize;			/* 10 */
23 	u8	_reserved0[16 - 11];	/* 11-15 */
24 	u16	ncpurl;			/* 16-17 */
25 	u8	_reserved7[24 - 18];	/* 18-23 */
26 	u8	loadparm[8];		/* 24-31 */
27 	u8	_reserved1[48 - 32];	/* 32-47 */
28 	u64	facilities;		/* 48-55 */
29 	u8	_reserved2[84 - 56];	/* 56-83 */
30 	u8	fac84;			/* 84 */
31 	u8	fac85;			/* 85 */
32 	u8	_reserved3[91 - 86];	/* 86-90 */
33 	u8	flags;			/* 91 */
34 	u8	_reserved4[100 - 92];	/* 92-99 */
35 	u32	rnsize2;		/* 100-103 */
36 	u64	rnmax2;			/* 104-111 */
37 	u8	_reserved5[120 - 112];	/* 112-119 */
38 	u16	hcpua;			/* 120-121 */
39 	u8	_reserved6[4096 - 122];	/* 122-4095 */
40 } __packed __aligned(PAGE_SIZE);
41 
42 static char sccb_early[PAGE_SIZE] __aligned(PAGE_SIZE) __initdata;
43 static unsigned int sclp_con_has_vt220 __initdata;
44 static unsigned int sclp_con_has_linemode __initdata;
45 static unsigned long sclp_hsa_size;
46 static unsigned int sclp_max_cpu;
47 static struct sclp_ipl_info sclp_ipl_info;
48 
49 u64 sclp_facilities;
50 u8 sclp_fac84;
51 unsigned long long sclp_rzm;
52 unsigned long long sclp_rnmax;
53 
54 static int __init sclp_cmd_sync_early(sclp_cmdw_t cmd, void *sccb)
55 {
56 	int rc;
57 
58 	__ctl_set_bit(0, 9);
59 	rc = sclp_service_call(cmd, sccb);
60 	if (rc)
61 		goto out;
62 	__load_psw_mask(PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_MASK_EA |
63 			PSW_MASK_BA | PSW_MASK_EXT | PSW_MASK_WAIT);
64 	local_irq_disable();
65 out:
66 	/* Contents of the sccb might have changed. */
67 	barrier();
68 	__ctl_clear_bit(0, 9);
69 	return rc;
70 }
71 
72 static int __init sclp_read_info_early(struct read_info_sccb *sccb)
73 {
74 	int rc, i;
75 	sclp_cmdw_t commands[] = {SCLP_CMDW_READ_SCP_INFO_FORCED,
76 				  SCLP_CMDW_READ_SCP_INFO};
77 
78 	for (i = 0; i < ARRAY_SIZE(commands); i++) {
79 		do {
80 			memset(sccb, 0, sizeof(*sccb));
81 			sccb->header.length = sizeof(*sccb);
82 			sccb->header.function_code = 0x80;
83 			sccb->header.control_mask[2] = 0x80;
84 			rc = sclp_cmd_sync_early(commands[i], sccb);
85 		} while (rc == -EBUSY);
86 
87 		if (rc)
88 			break;
89 		if (sccb->header.response_code == 0x10)
90 			return 0;
91 		if (sccb->header.response_code != 0x1f0)
92 			break;
93 	}
94 	return -EIO;
95 }
96 
97 static void __init sclp_facilities_detect(struct read_info_sccb *sccb)
98 {
99 	if (sclp_read_info_early(sccb))
100 		return;
101 
102 	sclp_facilities = sccb->facilities;
103 	sclp_fac84 = sccb->fac84;
104 	if (sccb->fac85 & 0x02)
105 		S390_lowcore.machine_flags |= MACHINE_FLAG_ESOP;
106 	sclp_rnmax = sccb->rnmax ? sccb->rnmax : sccb->rnmax2;
107 	sclp_rzm = sccb->rnsize ? sccb->rnsize : sccb->rnsize2;
108 	sclp_rzm <<= 20;
109 
110 	if (!sccb->hcpua) {
111 		if (MACHINE_IS_VM)
112 			sclp_max_cpu = 64;
113 		else
114 			sclp_max_cpu = sccb->ncpurl;
115 	} else {
116 		sclp_max_cpu = sccb->hcpua + 1;
117 	}
118 
119 	/* Save IPL information */
120 	sclp_ipl_info.is_valid = 1;
121 	if (sccb->flags & 0x2)
122 		sclp_ipl_info.has_dump = 1;
123 	memcpy(&sclp_ipl_info.loadparm, &sccb->loadparm, LOADPARM_LEN);
124 }
125 
126 bool __init sclp_has_linemode(void)
127 {
128 	return !!sclp_con_has_linemode;
129 }
130 
131 bool __init sclp_has_vt220(void)
132 {
133 	return !!sclp_con_has_vt220;
134 }
135 
136 unsigned long long sclp_get_rnmax(void)
137 {
138 	return sclp_rnmax;
139 }
140 
141 unsigned long long sclp_get_rzm(void)
142 {
143 	return sclp_rzm;
144 }
145 
146 unsigned int sclp_get_max_cpu(void)
147 {
148 	return sclp_max_cpu;
149 }
150 
151 /*
152  * This function will be called after sclp_facilities_detect(), which gets
153  * called from early.c code. The sclp_facilities_detect() function retrieves
154  * and saves the IPL information.
155  */
156 void __init sclp_get_ipl_info(struct sclp_ipl_info *info)
157 {
158 	*info = sclp_ipl_info;
159 }
160 
161 static int __init sclp_cmd_early(sclp_cmdw_t cmd, void *sccb)
162 {
163 	int rc;
164 
165 	do {
166 		rc = sclp_cmd_sync_early(cmd, sccb);
167 	} while (rc == -EBUSY);
168 
169 	if (rc)
170 		return -EIO;
171 	if (((struct sccb_header *) sccb)->response_code != 0x0020)
172 		return -EIO;
173 	return 0;
174 }
175 
176 static void __init sccb_init_eq_size(struct sdias_sccb *sccb)
177 {
178 	memset(sccb, 0, sizeof(*sccb));
179 
180 	sccb->hdr.length = sizeof(*sccb);
181 	sccb->evbuf.hdr.length = sizeof(struct sdias_evbuf);
182 	sccb->evbuf.hdr.type = EVTYP_SDIAS;
183 	sccb->evbuf.event_qual = SDIAS_EQ_SIZE;
184 	sccb->evbuf.data_id = SDIAS_DI_FCP_DUMP;
185 	sccb->evbuf.event_id = 4712;
186 	sccb->evbuf.dbs = 1;
187 }
188 
189 static int __init sclp_set_event_mask(struct init_sccb *sccb,
190 				      unsigned long receive_mask,
191 				      unsigned long send_mask)
192 {
193 	memset(sccb, 0, sizeof(*sccb));
194 	sccb->header.length = sizeof(*sccb);
195 	sccb->mask_length = sizeof(sccb_mask_t);
196 	sccb->receive_mask = receive_mask;
197 	sccb->send_mask = send_mask;
198 	return sclp_cmd_early(SCLP_CMDW_WRITE_EVENT_MASK, sccb);
199 }
200 
201 static long __init sclp_hsa_size_init(struct sdias_sccb *sccb)
202 {
203 	sccb_init_eq_size(sccb);
204 	if (sclp_cmd_early(SCLP_CMDW_WRITE_EVENT_DATA, sccb))
205 		return -EIO;
206 	if (sccb->evbuf.blk_cnt == 0)
207 		return 0;
208 	return (sccb->evbuf.blk_cnt - 1) * PAGE_SIZE;
209 }
210 
211 static long __init sclp_hsa_copy_wait(struct sccb_header *sccb)
212 {
213 	memset(sccb, 0, PAGE_SIZE);
214 	sccb->length = PAGE_SIZE;
215 	if (sclp_cmd_early(SCLP_CMDW_READ_EVENT_DATA, sccb))
216 		return -EIO;
217 	if (((struct sdias_sccb *) sccb)->evbuf.blk_cnt == 0)
218 		return 0;
219 	return (((struct sdias_sccb *) sccb)->evbuf.blk_cnt - 1) * PAGE_SIZE;
220 }
221 
222 unsigned long sclp_get_hsa_size(void)
223 {
224 	return sclp_hsa_size;
225 }
226 
227 static void __init sclp_hsa_size_detect(void *sccb)
228 {
229 	long size;
230 
231 	/* First try synchronous interface (LPAR) */
232 	if (sclp_set_event_mask(sccb, 0, 0x40000010))
233 		return;
234 	size = sclp_hsa_size_init(sccb);
235 	if (size < 0)
236 		return;
237 	if (size != 0)
238 		goto out;
239 	/* Then try asynchronous interface (z/VM) */
240 	if (sclp_set_event_mask(sccb, 0x00000010, 0x40000010))
241 		return;
242 	size = sclp_hsa_size_init(sccb);
243 	if (size < 0)
244 		return;
245 	size = sclp_hsa_copy_wait(sccb);
246 	if (size < 0)
247 		return;
248 out:
249 	sclp_hsa_size = size;
250 }
251 
252 static unsigned int __init sclp_con_check_linemode(struct init_sccb *sccb)
253 {
254 	if (!(sccb->sclp_send_mask & (EVTYP_OPCMD_MASK | EVTYP_PMSGCMD_MASK)))
255 		return 0;
256 	if (!(sccb->sclp_receive_mask & (EVTYP_MSG_MASK | EVTYP_PMSGCMD_MASK)))
257 		return 0;
258 	return 1;
259 }
260 
261 static void __init sclp_console_detect(struct init_sccb *sccb)
262 {
263 	if (sccb->header.response_code != 0x20)
264 		return;
265 
266 	if (sccb->sclp_send_mask & EVTYP_VT220MSG_MASK)
267 		sclp_con_has_vt220 = 1;
268 
269 	if (sclp_con_check_linemode(sccb))
270 		sclp_con_has_linemode = 1;
271 }
272 
273 void __init sclp_early_detect(void)
274 {
275 	void *sccb = &sccb_early;
276 
277 	sclp_facilities_detect(sccb);
278 	sclp_hsa_size_detect(sccb);
279 
280 	/* Turn off SCLP event notifications.  Also save remote masks in the
281 	 * sccb.  These are sufficient to detect sclp console capabilities.
282 	 */
283 	sclp_set_event_mask(sccb, 0, 0);
284 	sclp_console_detect(sccb);
285 }
286