1 /*
2 * DIAGNOSE X'2C4' instruction based HMC FTP services, useable on z/VM
3 *
4 * Copyright IBM Corp. 2013
5 * Author(s): Ralf Hoppe (rhoppe@de.ibm.com)
6 *
7 */
8
9 #define KMSG_COMPONENT "hmcdrv"
10 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
11
12 #include <linux/kernel.h>
13 #include <linux/mm.h>
14 #include <linux/irq.h>
15 #include <linux/wait.h>
16 #include <linux/string.h>
17 #include <asm/ctl_reg.h>
18
19 #include "hmcdrv_ftp.h"
20 #include "diag_ftp.h"
21
22 /* DIAGNOSE X'2C4' return codes in Ry */
23 #define DIAG_FTP_RET_OK 0 /* HMC FTP started successfully */
24 #define DIAG_FTP_RET_EBUSY 4 /* HMC FTP service currently busy */
25 #define DIAG_FTP_RET_EIO 8 /* HMC FTP service I/O error */
26 /* and an artificial extension */
27 #define DIAG_FTP_RET_EPERM 2 /* HMC FTP service privilege error */
28
29 /* FTP service status codes (after INTR at guest real location 133) */
30 #define DIAG_FTP_STAT_OK 0U /* request completed successfully */
31 #define DIAG_FTP_STAT_PGCC 4U /* program check condition */
32 #define DIAG_FTP_STAT_PGIOE 8U /* paging I/O error */
33 #define DIAG_FTP_STAT_TIMEOUT 12U /* timeout */
34 #define DIAG_FTP_STAT_EBASE 16U /* base of error codes from SCLP */
35 #define DIAG_FTP_STAT_LDFAIL (DIAG_FTP_STAT_EBASE + 1U) /* failed */
36 #define DIAG_FTP_STAT_LDNPERM (DIAG_FTP_STAT_EBASE + 2U) /* not allowed */
37 #define DIAG_FTP_STAT_LDRUNS (DIAG_FTP_STAT_EBASE + 3U) /* runs */
38 #define DIAG_FTP_STAT_LDNRUNS (DIAG_FTP_STAT_EBASE + 4U) /* not runs */
39
40 /**
41 * struct diag_ftp_ldfpl - load file FTP parameter list (LDFPL)
42 * @bufaddr: real buffer address (at 4k boundary)
43 * @buflen: length of buffer
44 * @offset: dir/file offset
45 * @intparm: interruption parameter (unused)
46 * @transferred: bytes transferred
47 * @fsize: file size, filled on GET
48 * @failaddr: failing address
49 * @spare: padding
50 * @fident: file name - ASCII
51 */
52 struct diag_ftp_ldfpl {
53 u64 bufaddr;
54 u64 buflen;
55 u64 offset;
56 u64 intparm;
57 u64 transferred;
58 u64 fsize;
59 u64 failaddr;
60 u64 spare;
61 u8 fident[HMCDRV_FTP_FIDENT_MAX];
62 } __packed;
63
64 static DECLARE_COMPLETION(diag_ftp_rx_complete);
65 static int diag_ftp_subcode;
66
67 /**
68 * diag_ftp_handler() - FTP services IRQ handler
69 * @extirq: external interrupt (sub-) code
70 * @param32: 32-bit interruption parameter from &struct diag_ftp_ldfpl
71 * @param64: unused (for 64-bit interrupt parameters)
72 */
diag_ftp_handler(struct ext_code extirq,unsigned int param32,unsigned long param64)73 static void diag_ftp_handler(struct ext_code extirq,
74 unsigned int param32,
75 unsigned long param64)
76 {
77 if ((extirq.subcode >> 8) != 8)
78 return; /* not a FTP services sub-code */
79
80 inc_irq_stat(IRQEXT_FTP);
81 diag_ftp_subcode = extirq.subcode & 0xffU;
82 complete(&diag_ftp_rx_complete);
83 }
84
85 /**
86 * diag_ftp_2c4() - DIAGNOSE X'2C4' service call
87 * @fpl: pointer to prepared LDFPL
88 * @cmd: FTP command to be executed
89 *
90 * Performs a DIAGNOSE X'2C4' call with (input/output) FTP parameter list
91 * @fpl and FTP function code @cmd. In case of an error the function does
92 * nothing and returns an (negative) error code.
93 *
94 * Notes:
95 * 1. This function only initiates a transfer, so the caller must wait
96 * for completion (asynchronous execution).
97 * 2. The FTP parameter list @fpl must be aligned to a double-word boundary.
98 * 3. fpl->bufaddr must be a real address, 4k aligned
99 */
diag_ftp_2c4(struct diag_ftp_ldfpl * fpl,enum hmcdrv_ftp_cmdid cmd)100 static int diag_ftp_2c4(struct diag_ftp_ldfpl *fpl,
101 enum hmcdrv_ftp_cmdid cmd)
102 {
103 int rc;
104
105 asm volatile(
106 " diag %[addr],%[cmd],0x2c4\n"
107 "0: j 2f\n"
108 "1: la %[rc],%[err]\n"
109 "2:\n"
110 EX_TABLE(0b, 1b)
111 : [rc] "=d" (rc), "+m" (*fpl)
112 : [cmd] "0" (cmd), [addr] "d" (virt_to_phys(fpl)),
113 [err] "i" (DIAG_FTP_RET_EPERM)
114 : "cc");
115
116 switch (rc) {
117 case DIAG_FTP_RET_OK:
118 return 0;
119 case DIAG_FTP_RET_EBUSY:
120 return -EBUSY;
121 case DIAG_FTP_RET_EPERM:
122 return -EPERM;
123 case DIAG_FTP_RET_EIO:
124 default:
125 return -EIO;
126 }
127 }
128
129 /**
130 * diag_ftp_cmd() - executes a DIAG X'2C4' FTP command, targeting a HMC
131 * @ftp: pointer to FTP command specification
132 * @fsize: return of file size (or NULL if undesirable)
133 *
134 * Attention: Notice that this function is not reentrant - so the caller
135 * must ensure locking.
136 *
137 * Return: number of bytes read/written or a (negative) error code
138 */
diag_ftp_cmd(const struct hmcdrv_ftp_cmdspec * ftp,size_t * fsize)139 ssize_t diag_ftp_cmd(const struct hmcdrv_ftp_cmdspec *ftp, size_t *fsize)
140 {
141 struct diag_ftp_ldfpl *ldfpl;
142 ssize_t len;
143 #ifdef DEBUG
144 unsigned long start_jiffies;
145
146 pr_debug("starting DIAG X'2C4' on '%s', requesting %zd bytes\n",
147 ftp->fname, ftp->len);
148 start_jiffies = jiffies;
149 #endif
150 init_completion(&diag_ftp_rx_complete);
151
152 ldfpl = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
153 if (!ldfpl) {
154 len = -ENOMEM;
155 goto out;
156 }
157
158 len = strlcpy(ldfpl->fident, ftp->fname, sizeof(ldfpl->fident));
159 if (len >= HMCDRV_FTP_FIDENT_MAX) {
160 len = -EINVAL;
161 goto out_free;
162 }
163
164 ldfpl->transferred = 0;
165 ldfpl->fsize = 0;
166 ldfpl->offset = ftp->ofs;
167 ldfpl->buflen = ftp->len;
168 ldfpl->bufaddr = virt_to_phys(ftp->buf);
169
170 len = diag_ftp_2c4(ldfpl, ftp->id);
171 if (len)
172 goto out_free;
173
174 /*
175 * There is no way to cancel the running diag X'2C4', the code
176 * needs to wait unconditionally until the transfer is complete.
177 */
178 wait_for_completion(&diag_ftp_rx_complete);
179
180 #ifdef DEBUG
181 pr_debug("completed DIAG X'2C4' after %lu ms\n",
182 (jiffies - start_jiffies) * 1000 / HZ);
183 pr_debug("status of DIAG X'2C4' is %u, with %lld/%lld bytes\n",
184 diag_ftp_subcode, ldfpl->transferred, ldfpl->fsize);
185 #endif
186
187 switch (diag_ftp_subcode) {
188 case DIAG_FTP_STAT_OK: /* success */
189 len = ldfpl->transferred;
190 if (fsize)
191 *fsize = ldfpl->fsize;
192 break;
193 case DIAG_FTP_STAT_LDNPERM:
194 len = -EPERM;
195 break;
196 case DIAG_FTP_STAT_LDRUNS:
197 len = -EBUSY;
198 break;
199 case DIAG_FTP_STAT_LDFAIL:
200 len = -ENOENT; /* no such file or media */
201 break;
202 default:
203 len = -EIO;
204 break;
205 }
206
207 out_free:
208 free_page((unsigned long) ldfpl);
209 out:
210 return len;
211 }
212
213 /**
214 * diag_ftp_startup() - startup of FTP services, when running on z/VM
215 *
216 * Return: 0 on success, else an (negative) error code
217 */
diag_ftp_startup(void)218 int diag_ftp_startup(void)
219 {
220 int rc;
221
222 rc = register_external_irq(EXT_IRQ_CP_SERVICE, diag_ftp_handler);
223 if (rc)
224 return rc;
225
226 ctl_set_bit(0, 63 - 22);
227 return 0;
228 }
229
230 /**
231 * diag_ftp_shutdown() - shutdown of FTP services, when running on z/VM
232 */
diag_ftp_shutdown(void)233 void diag_ftp_shutdown(void)
234 {
235 ctl_clear_bit(0, 63 - 22);
236 unregister_external_irq(EXT_IRQ_CP_SERVICE, diag_ftp_handler);
237 }
238