xref: /openbmc/linux/drivers/s390/char/sclp_early.c (revision 8a10bc9d)
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[24 - 11];	/* 11-15 */
24 	u8	loadparm[8];		/* 24-31 */
25 	u8	_reserved1[48 - 32];	/* 32-47 */
26 	u64	facilities;		/* 48-55 */
27 	u8	_reserved2[84 - 56];	/* 56-83 */
28 	u8	fac84;			/* 84 */
29 	u8	fac85;			/* 85 */
30 	u8	_reserved3[91 - 86];	/* 86-90 */
31 	u8	flags;			/* 91 */
32 	u8	_reserved4[100 - 92];	/* 92-99 */
33 	u32	rnsize2;		/* 100-103 */
34 	u64	rnmax2;			/* 104-111 */
35 	u8	_reserved5[4096 - 112];	/* 112-4095 */
36 } __packed __aligned(PAGE_SIZE);
37 
38 static char sccb_early[PAGE_SIZE] __aligned(PAGE_SIZE) __initdata;
39 static unsigned int sclp_con_has_vt220 __initdata;
40 static unsigned int sclp_con_has_linemode __initdata;
41 static unsigned long sclp_hsa_size;
42 static struct sclp_ipl_info sclp_ipl_info;
43 
44 u64 sclp_facilities;
45 u8 sclp_fac84;
46 unsigned long long sclp_rzm;
47 unsigned long long sclp_rnmax;
48 
49 static int __init sclp_cmd_sync_early(sclp_cmdw_t cmd, void *sccb)
50 {
51 	int rc;
52 
53 	__ctl_set_bit(0, 9);
54 	rc = sclp_service_call(cmd, sccb);
55 	if (rc)
56 		goto out;
57 	__load_psw_mask(PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_MASK_EA |
58 			PSW_MASK_BA | PSW_MASK_EXT | PSW_MASK_WAIT);
59 	local_irq_disable();
60 out:
61 	/* Contents of the sccb might have changed. */
62 	barrier();
63 	__ctl_clear_bit(0, 9);
64 	return rc;
65 }
66 
67 static int __init sclp_read_info_early(struct read_info_sccb *sccb)
68 {
69 	int rc, i;
70 	sclp_cmdw_t commands[] = {SCLP_CMDW_READ_SCP_INFO_FORCED,
71 				  SCLP_CMDW_READ_SCP_INFO};
72 
73 	for (i = 0; i < ARRAY_SIZE(commands); i++) {
74 		do {
75 			memset(sccb, 0, sizeof(*sccb));
76 			sccb->header.length = sizeof(*sccb);
77 			sccb->header.function_code = 0x80;
78 			sccb->header.control_mask[2] = 0x80;
79 			rc = sclp_cmd_sync_early(commands[i], sccb);
80 		} while (rc == -EBUSY);
81 
82 		if (rc)
83 			break;
84 		if (sccb->header.response_code == 0x10)
85 			return 0;
86 		if (sccb->header.response_code != 0x1f0)
87 			break;
88 	}
89 	return -EIO;
90 }
91 
92 static void __init sclp_facilities_detect(struct read_info_sccb *sccb)
93 {
94 	if (sclp_read_info_early(sccb))
95 		return;
96 
97 	sclp_facilities = sccb->facilities;
98 	sclp_fac84 = sccb->fac84;
99 	if (sccb->fac85 & 0x02)
100 		S390_lowcore.machine_flags |= MACHINE_FLAG_ESOP;
101 	sclp_rnmax = sccb->rnmax ? sccb->rnmax : sccb->rnmax2;
102 	sclp_rzm = sccb->rnsize ? sccb->rnsize : sccb->rnsize2;
103 	sclp_rzm <<= 20;
104 
105 	/* Save IPL information */
106 	sclp_ipl_info.is_valid = 1;
107 	if (sccb->flags & 0x2)
108 		sclp_ipl_info.has_dump = 1;
109 	memcpy(&sclp_ipl_info.loadparm, &sccb->loadparm, LOADPARM_LEN);
110 }
111 
112 bool __init sclp_has_linemode(void)
113 {
114 	return !!sclp_con_has_linemode;
115 }
116 
117 bool __init sclp_has_vt220(void)
118 {
119 	return !!sclp_con_has_vt220;
120 }
121 
122 unsigned long long sclp_get_rnmax(void)
123 {
124 	return sclp_rnmax;
125 }
126 
127 unsigned long long sclp_get_rzm(void)
128 {
129 	return sclp_rzm;
130 }
131 
132 /*
133  * This function will be called after sclp_facilities_detect(), which gets
134  * called from early.c code. The sclp_facilities_detect() function retrieves
135  * and saves the IPL information.
136  */
137 void __init sclp_get_ipl_info(struct sclp_ipl_info *info)
138 {
139 	*info = sclp_ipl_info;
140 }
141 
142 static int __init sclp_cmd_early(sclp_cmdw_t cmd, void *sccb)
143 {
144 	int rc;
145 
146 	do {
147 		rc = sclp_cmd_sync_early(cmd, sccb);
148 	} while (rc == -EBUSY);
149 
150 	if (rc)
151 		return -EIO;
152 	if (((struct sccb_header *) sccb)->response_code != 0x0020)
153 		return -EIO;
154 	return 0;
155 }
156 
157 static void __init sccb_init_eq_size(struct sdias_sccb *sccb)
158 {
159 	memset(sccb, 0, sizeof(*sccb));
160 
161 	sccb->hdr.length = sizeof(*sccb);
162 	sccb->evbuf.hdr.length = sizeof(struct sdias_evbuf);
163 	sccb->evbuf.hdr.type = EVTYP_SDIAS;
164 	sccb->evbuf.event_qual = SDIAS_EQ_SIZE;
165 	sccb->evbuf.data_id = SDIAS_DI_FCP_DUMP;
166 	sccb->evbuf.event_id = 4712;
167 	sccb->evbuf.dbs = 1;
168 }
169 
170 static int __init sclp_set_event_mask(struct init_sccb *sccb,
171 				      unsigned long receive_mask,
172 				      unsigned long send_mask)
173 {
174 	memset(sccb, 0, sizeof(*sccb));
175 	sccb->header.length = sizeof(*sccb);
176 	sccb->mask_length = sizeof(sccb_mask_t);
177 	sccb->receive_mask = receive_mask;
178 	sccb->send_mask = send_mask;
179 	return sclp_cmd_early(SCLP_CMDW_WRITE_EVENT_MASK, sccb);
180 }
181 
182 static long __init sclp_hsa_size_init(struct sdias_sccb *sccb)
183 {
184 	sccb_init_eq_size(sccb);
185 	if (sclp_cmd_early(SCLP_CMDW_WRITE_EVENT_DATA, sccb))
186 		return -EIO;
187 	if (sccb->evbuf.blk_cnt != 0)
188 		return (sccb->evbuf.blk_cnt - 1) * PAGE_SIZE;
189 	return 0;
190 }
191 
192 static long __init sclp_hsa_copy_wait(struct sccb_header *sccb)
193 {
194 	memset(sccb, 0, PAGE_SIZE);
195 	sccb->length = PAGE_SIZE;
196 	if (sclp_cmd_early(SCLP_CMDW_READ_EVENT_DATA, sccb))
197 		return -EIO;
198 	return (((struct sdias_sccb *) sccb)->evbuf.blk_cnt - 1) * PAGE_SIZE;
199 }
200 
201 unsigned long sclp_get_hsa_size(void)
202 {
203 	return sclp_hsa_size;
204 }
205 
206 static void __init sclp_hsa_size_detect(void *sccb)
207 {
208 	long size;
209 
210 	/* First try synchronous interface (LPAR) */
211 	if (sclp_set_event_mask(sccb, 0, 0x40000010))
212 		return;
213 	size = sclp_hsa_size_init(sccb);
214 	if (size < 0)
215 		return;
216 	if (size != 0)
217 		goto out;
218 	/* Then try asynchronous interface (z/VM) */
219 	if (sclp_set_event_mask(sccb, 0x00000010, 0x40000010))
220 		return;
221 	size = sclp_hsa_size_init(sccb);
222 	if (size < 0)
223 		return;
224 	size = sclp_hsa_copy_wait(sccb);
225 	if (size < 0)
226 		return;
227 out:
228 	sclp_hsa_size = size;
229 }
230 
231 static unsigned int __init sclp_con_check_linemode(struct init_sccb *sccb)
232 {
233 	if (!(sccb->sclp_send_mask & (EVTYP_OPCMD_MASK | EVTYP_PMSGCMD_MASK)))
234 		return 0;
235 	if (!(sccb->sclp_receive_mask & (EVTYP_MSG_MASK | EVTYP_PMSGCMD_MASK)))
236 		return 0;
237 	return 1;
238 }
239 
240 static void __init sclp_console_detect(struct init_sccb *sccb)
241 {
242 	if (sccb->header.response_code != 0x20)
243 		return;
244 
245 	if (sccb->sclp_send_mask & EVTYP_VT220MSG_MASK)
246 		sclp_con_has_vt220 = 1;
247 
248 	if (sclp_con_check_linemode(sccb))
249 		sclp_con_has_linemode = 1;
250 }
251 
252 void __init sclp_early_detect(void)
253 {
254 	void *sccb = &sccb_early;
255 
256 	sclp_facilities_detect(sccb);
257 	sclp_hsa_size_detect(sccb);
258 
259 	/* Turn off SCLP event notifications.  Also save remote masks in the
260 	 * sccb.  These are sufficient to detect sclp console capabilities.
261 	 */
262 	sclp_set_event_mask(sccb, 0, 0);
263 	sclp_console_detect(sccb);
264 }
265