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
 20struct 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
 55static char sccb_early[PAGE_SIZE] __aligned(PAGE_SIZE) __initdata;
 56static struct sclp_ipl_info sclp_ipl_info;
 57
 58struct sclp_info sclp;
 59EXPORT_SYMBOL(sclp);
 60
 61static 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();
 72out:
 73	/* Contents of the sccb might have changed. */
 74	barrier();
 75	__ctl_clear_bit(0, 9);
 76	return rc;
 77}
 78
 79static 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
104static 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 */
165void __init sclp_get_ipl_info(struct sclp_ipl_info *info)
166{
167	*info = sclp_ipl_info;
168}
169
170static 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
185static 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
198static 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
210static 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
220static 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
231static 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;
252out:
253	sclp.hsa_size = size;
254}
255
256static 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
265static 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
277void __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}