summaryrefslogtreecommitdiffstats
path: root/drivers/s390/char/diag_ftp.c
blob: 12db8db04cddf61832b243709e16c7fc0a1ae5ca (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
/*
 *    DIAGNOSE X'2C4' instruction based HMC FTP services, useable on z/VM
 *
 *    Copyright IBM Corp. 2013
 *    Author(s): Ralf Hoppe (rhoppe@de.ibm.com)
 *
 */

#define KMSG_COMPONENT "hmcdrv"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/irq.h>
#include <linux/wait.h>
#include <linux/string.h>
#include <asm/ctl_reg.h>

#include "hmcdrv_ftp.h"
#include "diag_ftp.h"

/* DIAGNOSE X'2C4' return codes in Ry */
#define DIAG_FTP_RET_OK	0 /* HMC FTP started successfully */
#define DIAG_FTP_RET_EBUSY	4 /* HMC FTP service currently busy */
#define DIAG_FTP_RET_EIO	8 /* HMC FTP service I/O error */
/* and an artificial extension */
#define DIAG_FTP_RET_EPERM	2 /* HMC FTP service privilege error */

/* FTP service status codes (after INTR at guest real location 133) */
#define DIAG_FTP_STAT_OK	0U /* request completed successfully */
#define DIAG_FTP_STAT_PGCC	4U /* program check condition */
#define DIAG_FTP_STAT_PGIOE	8U /* paging I/O error */
#define DIAG_FTP_STAT_TIMEOUT	12U /* timeout */
#define DIAG_FTP_STAT_EBASE	16U /* base of error codes from SCLP */
#define DIAG_FTP_STAT_LDFAIL	(DIAG_FTP_STAT_EBASE + 1U) /* failed */
#define DIAG_FTP_STAT_LDNPERM	(DIAG_FTP_STAT_EBASE + 2U) /* not allowed */
#define DIAG_FTP_STAT_LDRUNS	(DIAG_FTP_STAT_EBASE + 3U) /* runs */
#define DIAG_FTP_STAT_LDNRUNS	(DIAG_FTP_STAT_EBASE + 4U) /* not runs */

/**
 * struct diag_ftp_ldfpl - load file FTP parameter list (LDFPL)
 * @bufaddr: real buffer address (at 4k boundary)
 * @buflen: length of buffer
 * @offset: dir/file offset
 * @intparm: interruption parameter (unused)
 * @transferred: bytes transferred
 * @fsize: file size, filled on GET
 * @failaddr: failing address
 * @spare: padding
 * @fident: file name - ASCII
 */
struct diag_ftp_ldfpl {
	u64 bufaddr;
	u64 buflen;
	u64 offset;
	u64 intparm;
	u64 transferred;
	u64 fsize;
	u64 failaddr;
	u64 spare;
	u8 fident[HMCDRV_FTP_FIDENT_MAX];
} __packed;

static DECLARE_COMPLETION(diag_ftp_rx_complete);
static int diag_ftp_subcode;

/**
 * diag_ftp_handler() - FTP services IRQ handler
 * @extirq: external interrupt (sub-) code
 * @param32: 32-bit interruption parameter from &struct diag_ftp_ldfpl
 * @param64: unused (for 64-bit interrupt parameters)
 */
static void diag_ftp_handler(struct ext_code extirq,
			     unsigned int param32,
			     unsigned long param64)
{
	if ((extirq.subcode >> 8) != 8)
		return; /* not a FTP services sub-code */

	inc_irq_stat(IRQEXT_FTP);
	diag_ftp_subcode = extirq.subcode & 0xffU;
	complete(&diag_ftp_rx_complete);
}

/**
 * diag_ftp_2c4() - DIAGNOSE X'2C4' service call
 * @fpl: pointer to prepared LDFPL
 * @cmd: FTP command to be executed
 *
 * Performs a DIAGNOSE X'2C4' call with (input/output) FTP parameter list
 * @fpl and FTP function code @cmd. In case of an error the function does
 * nothing and returns an (negative) error code.
 *
 * Notes:
 * 1. This function only initiates a transfer, so the caller must wait
 *    for completion (asynchronous execution).
 * 2. The FTP parameter list @fpl must be aligned to a double-word boundary.
 * 3. fpl->bufaddr must be a real address, 4k aligned
 */
static int diag_ftp_2c4(struct diag_ftp_ldfpl *fpl,
			enum hmcdrv_ftp_cmdid cmd)
{
	int rc;

	asm volatile(
		"	diag	%[addr],%[cmd],0x2c4\n"
		"0:	j	2f\n"
		"1:	la	%[rc],%[err]\n"
		"2:\n"
		EX_TABLE(0b, 1b)
		: [rc] "=d" (rc), "+m" (*fpl)
		: [cmd] "0" (cmd), [addr] "d" (virt_to_phys(fpl)),
		  [err] "i" (DIAG_FTP_RET_EPERM)
		: "cc");

	switch (rc) {
	case DIAG_FTP_RET_OK:
		return 0;
	case DIAG_FTP_RET_EBUSY:
		return -EBUSY;
	case DIAG_FTP_RET_EPERM:
		return -EPERM;
	case DIAG_FTP_RET_EIO:
	default:
		return -EIO;
	}
}

/**
 * diag_ftp_cmd() - executes a DIAG X'2C4' FTP command, targeting a HMC
 * @ftp: pointer to FTP command specification
 * @fsize: return of file size (or NULL if undesirable)
 *
 * Attention: Notice that this function is not reentrant - so the caller
 * must ensure locking.
 *
 * Return: number of bytes read/written or a (negative) error code
 */
ssize_t diag_ftp_cmd(const struct hmcdrv_ftp_cmdspec *ftp, size_t *fsize)
{
	struct diag_ftp_ldfpl *ldfpl;
	ssize_t len;
#ifdef DEBUG
	unsigned long start_jiffies;

	pr_debug("starting DIAG X'2C4' on '%s', requesting %zd bytes\n",
		 ftp->fname, ftp->len);
	start_jiffies = jiffies;
#endif
	init_completion(&diag_ftp_rx_complete);

	ldfpl = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
	if (!ldfpl) {
		len = -ENOMEM;
		goto out;
	}

	len = strlcpy(ldfpl->fident, ftp->fname, sizeof(ldfpl->fident));
	if (len >= HMCDRV_FTP_FIDENT_MAX) {
		len = -EINVAL;
		goto out_free;
	}

	ldfpl->transferred = 0;
	ldfpl->fsize = 0;
	ldfpl->offset = ftp->ofs;
	ldfpl->buflen = ftp->len;
	ldfpl->bufaddr = virt_to_phys(ftp->buf);

	len = diag_ftp_2c4(ldfpl, ftp->id);
	if (len)
		goto out_free;

	/*
	 * There is no way to cancel the running diag X'2C4', the code
	 * needs to wait unconditionally until the transfer is complete.
	 */
	wait_for_completion(&diag_ftp_rx_complete);

#ifdef DEBUG
	pr_debug("completed DIAG X'2C4' after %lu ms\n",
		 (jiffies - start_jiffies) * 1000 / HZ);
	pr_debug("status of DIAG X'2C4' is %u, with %lld/%lld bytes\n",
		 diag_ftp_subcode, ldfpl->transferred, ldfpl->fsize);
#endif

	switch (diag_ftp_subcode) {
	case DIAG_FTP_STAT_OK: /* success */
		len = ldfpl->transferred;
		if (fsize)
			*fsize = ldfpl->fsize;
		break;
	case DIAG_FTP_STAT_LDNPERM:
		len = -EPERM;
		break;
	case DIAG_FTP_STAT_LDRUNS:
		len = -EBUSY;
		break;
	case DIAG_FTP_STAT_LDFAIL:
		len = -ENOENT; /* no such file or media */
		break;
	default:
		len = -EIO;
		break;
	}

out_free:
	free_page((unsigned long) ldfpl);
out:
	return len;
}

/**
 * diag_ftp_startup() - startup of FTP services, when running on z/VM
 *
 * Return: 0 on success, else an (negative) error code
 */
int diag_ftp_startup(void)
{
	int rc;

	rc = register_external_irq(EXT_IRQ_CP_SERVICE, diag_ftp_handler);
	if (rc)
		return rc;

	irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL);
	return 0;
}

/**
 * diag_ftp_shutdown() - shutdown of FTP services, when running on z/VM
 */
void diag_ftp_shutdown(void)
{
	irq_subclass_unregister(IRQ_SUBCLASS_SERVICE_SIGNAL);
	unregister_external_irq(EXT_IRQ_CP_SERVICE, diag_ftp_handler);
}
OpenPOWER on IntegriCloud