xref: /openbmc/linux/drivers/s390/char/sclp_early.c (revision 79f08d9e)
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 __initdata struct init_sccb early_event_mask_sccb __aligned(PAGE_SIZE);
39 static __initdata struct read_info_sccb early_read_info_sccb;
40 static __initdata char sccb_early[PAGE_SIZE] __aligned(PAGE_SIZE);
41 static unsigned long sclp_hsa_size;
42 
43 __initdata int sclp_early_read_info_sccb_valid;
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 void __init sclp_read_info_early(void)
68 {
69 	int rc;
70 	int i;
71 	struct read_info_sccb *sccb;
72 	sclp_cmdw_t commands[] = {SCLP_CMDW_READ_SCP_INFO_FORCED,
73 				  SCLP_CMDW_READ_SCP_INFO};
74 
75 	sccb = &early_read_info_sccb;
76 	for (i = 0; i < ARRAY_SIZE(commands); i++) {
77 		do {
78 			memset(sccb, 0, sizeof(*sccb));
79 			sccb->header.length = sizeof(*sccb);
80 			sccb->header.function_code = 0x80;
81 			sccb->header.control_mask[2] = 0x80;
82 			rc = sclp_cmd_sync_early(commands[i], sccb);
83 		} while (rc == -EBUSY);
84 
85 		if (rc)
86 			break;
87 		if (sccb->header.response_code == 0x10) {
88 			sclp_early_read_info_sccb_valid = 1;
89 			break;
90 		}
91 		if (sccb->header.response_code != 0x1f0)
92 			break;
93 	}
94 }
95 
96 static void __init sclp_facilities_detect(void)
97 {
98 	struct read_info_sccb *sccb;
99 
100 	sclp_read_info_early();
101 	if (!sclp_early_read_info_sccb_valid)
102 		return;
103 
104 	sccb = &early_read_info_sccb;
105 	sclp_facilities = sccb->facilities;
106 	sclp_fac84 = sccb->fac84;
107 	if (sccb->fac85 & 0x02)
108 		S390_lowcore.machine_flags |= MACHINE_FLAG_ESOP;
109 	sclp_rnmax = sccb->rnmax ? sccb->rnmax : sccb->rnmax2;
110 	sclp_rzm = sccb->rnsize ? sccb->rnsize : sccb->rnsize2;
111 	sclp_rzm <<= 20;
112 }
113 
114 bool __init sclp_has_linemode(void)
115 {
116 	struct init_sccb *sccb = &early_event_mask_sccb;
117 
118 	if (sccb->header.response_code != 0x20)
119 		return 0;
120 	if (!(sccb->sclp_send_mask & (EVTYP_OPCMD_MASK | EVTYP_PMSGCMD_MASK)))
121 		return 0;
122 	if (!(sccb->sclp_receive_mask & (EVTYP_MSG_MASK | EVTYP_PMSGCMD_MASK)))
123 		return 0;
124 	return 1;
125 }
126 
127 bool __init sclp_has_vt220(void)
128 {
129 	struct init_sccb *sccb = &early_event_mask_sccb;
130 
131 	if (sccb->header.response_code != 0x20)
132 		return 0;
133 	if (sccb->sclp_send_mask & EVTYP_VT220MSG_MASK)
134 		return 1;
135 	return 0;
136 }
137 
138 unsigned long long sclp_get_rnmax(void)
139 {
140 	return sclp_rnmax;
141 }
142 
143 unsigned long long sclp_get_rzm(void)
144 {
145 	return sclp_rzm;
146 }
147 
148 /*
149  * This function will be called after sclp_facilities_detect(), which gets
150  * called from early.c code. Therefore the sccb should have valid contents.
151  */
152 void __init sclp_get_ipl_info(struct sclp_ipl_info *info)
153 {
154 	struct read_info_sccb *sccb;
155 
156 	if (!sclp_early_read_info_sccb_valid)
157 		return;
158 	sccb = &early_read_info_sccb;
159 	info->is_valid = 1;
160 	if (sccb->flags & 0x2)
161 		info->has_dump = 1;
162 	memcpy(&info->loadparm, &sccb->loadparm, LOADPARM_LEN);
163 }
164 
165 static int __init sclp_cmd_early(sclp_cmdw_t cmd, void *sccb)
166 {
167 	int rc;
168 
169 	do {
170 		rc = sclp_cmd_sync_early(cmd, sccb);
171 	} while (rc == -EBUSY);
172 
173 	if (rc)
174 		return -EIO;
175 	if (((struct sccb_header *) sccb)->response_code != 0x0020)
176 		return -EIO;
177 	return 0;
178 }
179 
180 static void __init sccb_init_eq_size(struct sdias_sccb *sccb)
181 {
182 	memset(sccb, 0, sizeof(*sccb));
183 
184 	sccb->hdr.length = sizeof(*sccb);
185 	sccb->evbuf.hdr.length = sizeof(struct sdias_evbuf);
186 	sccb->evbuf.hdr.type = EVTYP_SDIAS;
187 	sccb->evbuf.event_qual = SDIAS_EQ_SIZE;
188 	sccb->evbuf.data_id = SDIAS_DI_FCP_DUMP;
189 	sccb->evbuf.event_id = 4712;
190 	sccb->evbuf.dbs = 1;
191 }
192 
193 static int __init sclp_set_event_mask(unsigned long receive_mask,
194 				      unsigned long send_mask)
195 {
196 	struct init_sccb *sccb = (void *) &sccb_early;
197 
198 	memset(sccb, 0, sizeof(*sccb));
199 	sccb->header.length = sizeof(*sccb);
200 	sccb->mask_length = sizeof(sccb_mask_t);
201 	sccb->receive_mask = receive_mask;
202 	sccb->send_mask = send_mask;
203 	return sclp_cmd_early(SCLP_CMDW_WRITE_EVENT_MASK, sccb);
204 }
205 
206 static long __init sclp_hsa_size_init(void)
207 {
208 	struct sdias_sccb *sccb = (void *) &sccb_early;
209 
210 	sccb_init_eq_size(sccb);
211 	if (sclp_cmd_early(SCLP_CMDW_WRITE_EVENT_DATA, sccb))
212 		return -EIO;
213 	if (sccb->evbuf.blk_cnt != 0)
214 		return (sccb->evbuf.blk_cnt - 1) * PAGE_SIZE;
215 	return 0;
216 }
217 
218 static long __init sclp_hsa_copy_wait(void)
219 {
220 	struct sccb_header *sccb = (void *) &sccb_early;
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 	return (((struct sdias_sccb *) sccb)->evbuf.blk_cnt - 1) * PAGE_SIZE;
227 }
228 
229 unsigned long sclp_get_hsa_size(void)
230 {
231 	return sclp_hsa_size;
232 }
233 
234 static void __init sclp_hsa_size_detect(void)
235 {
236 	long size;
237 
238 	/* First try synchronous interface (LPAR) */
239 	if (sclp_set_event_mask(0, 0x40000010))
240 		return;
241 	size = sclp_hsa_size_init();
242 	if (size < 0)
243 		return;
244 	if (size != 0)
245 		goto out;
246 	/* Then try asynchronous interface (z/VM) */
247 	if (sclp_set_event_mask(0x00000010, 0x40000010))
248 		return;
249 	size = sclp_hsa_size_init();
250 	if (size < 0)
251 		return;
252 	size = sclp_hsa_copy_wait();
253 	if (size < 0)
254 		return;
255 out:
256 	sclp_hsa_size = size;
257 }
258 
259 void __init sclp_early_detect(void)
260 {
261 	sclp_facilities_detect();
262 	sclp_hsa_size_detect();
263 	sclp_set_event_mask(0, 0);
264 }
265