1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * DIAGNOSE X'2C4' instruction based HMC FTP services, useable on z/VM |
4 | * |
5 | * Copyright IBM Corp. 2013 |
6 | * Author(s): Ralf Hoppe (rhoppe@de.ibm.com) |
7 | * |
8 | */ |
9 | |
10 | #define KMSG_COMPONENT "hmcdrv" |
11 | #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt |
12 | |
13 | #include <linux/kernel.h> |
14 | #include <linux/mm.h> |
15 | #include <linux/irq.h> |
16 | #include <linux/wait.h> |
17 | #include <linux/string.h> |
18 | #include <asm/asm-extable.h> |
19 | #include <asm/ctlreg.h> |
20 | #include <asm/diag.h> |
21 | |
22 | #include "hmcdrv_ftp.h" |
23 | #include "diag_ftp.h" |
24 | |
25 | /* DIAGNOSE X'2C4' return codes in Ry */ |
26 | #define DIAG_FTP_RET_OK 0 /* HMC FTP started successfully */ |
27 | #define DIAG_FTP_RET_EBUSY 4 /* HMC FTP service currently busy */ |
28 | #define DIAG_FTP_RET_EIO 8 /* HMC FTP service I/O error */ |
29 | /* and an artificial extension */ |
30 | #define DIAG_FTP_RET_EPERM 2 /* HMC FTP service privilege error */ |
31 | |
32 | /* FTP service status codes (after INTR at guest real location 133) */ |
33 | #define DIAG_FTP_STAT_OK 0U /* request completed successfully */ |
34 | #define DIAG_FTP_STAT_PGCC 4U /* program check condition */ |
35 | #define DIAG_FTP_STAT_PGIOE 8U /* paging I/O error */ |
36 | #define DIAG_FTP_STAT_TIMEOUT 12U /* timeout */ |
37 | #define DIAG_FTP_STAT_EBASE 16U /* base of error codes from SCLP */ |
38 | #define DIAG_FTP_STAT_LDFAIL (DIAG_FTP_STAT_EBASE + 1U) /* failed */ |
39 | #define DIAG_FTP_STAT_LDNPERM (DIAG_FTP_STAT_EBASE + 2U) /* not allowed */ |
40 | #define DIAG_FTP_STAT_LDRUNS (DIAG_FTP_STAT_EBASE + 3U) /* runs */ |
41 | #define DIAG_FTP_STAT_LDNRUNS (DIAG_FTP_STAT_EBASE + 4U) /* not runs */ |
42 | |
43 | /** |
44 | * struct diag_ftp_ldfpl - load file FTP parameter list (LDFPL) |
45 | * @bufaddr: real buffer address (at 4k boundary) |
46 | * @buflen: length of buffer |
47 | * @offset: dir/file offset |
48 | * @intparm: interruption parameter (unused) |
49 | * @transferred: bytes transferred |
50 | * @fsize: file size, filled on GET |
51 | * @failaddr: failing address |
52 | * @spare: padding |
53 | * @fident: file name - ASCII |
54 | */ |
55 | struct diag_ftp_ldfpl { |
56 | u64 bufaddr; |
57 | u64 buflen; |
58 | u64 offset; |
59 | u64 intparm; |
60 | u64 transferred; |
61 | u64 fsize; |
62 | u64 failaddr; |
63 | u64 spare; |
64 | u8 fident[HMCDRV_FTP_FIDENT_MAX]; |
65 | } __packed; |
66 | |
67 | static DECLARE_COMPLETION(diag_ftp_rx_complete); |
68 | static int diag_ftp_subcode; |
69 | |
70 | /** |
71 | * diag_ftp_handler() - FTP services IRQ handler |
72 | * @extirq: external interrupt (sub-) code |
73 | * @param32: 32-bit interruption parameter from &struct diag_ftp_ldfpl |
74 | * @param64: unused (for 64-bit interrupt parameters) |
75 | */ |
76 | static void diag_ftp_handler(struct ext_code extirq, |
77 | unsigned int param32, |
78 | unsigned long param64) |
79 | { |
80 | if ((extirq.subcode >> 8) != 8) |
81 | return; /* not a FTP services sub-code */ |
82 | |
83 | inc_irq_stat(IRQEXT_FTP); |
84 | diag_ftp_subcode = extirq.subcode & 0xffU; |
85 | complete(&diag_ftp_rx_complete); |
86 | } |
87 | |
88 | /** |
89 | * diag_ftp_2c4() - DIAGNOSE X'2C4' service call |
90 | * @fpl: pointer to prepared LDFPL |
91 | * @cmd: FTP command to be executed |
92 | * |
93 | * Performs a DIAGNOSE X'2C4' call with (input/output) FTP parameter list |
94 | * @fpl and FTP function code @cmd. In case of an error the function does |
95 | * nothing and returns an (negative) error code. |
96 | * |
97 | * Notes: |
98 | * 1. This function only initiates a transfer, so the caller must wait |
99 | * for completion (asynchronous execution). |
100 | * 2. The FTP parameter list @fpl must be aligned to a double-word boundary. |
101 | * 3. fpl->bufaddr must be a real address, 4k aligned |
102 | */ |
103 | static int diag_ftp_2c4(struct diag_ftp_ldfpl *fpl, |
104 | enum hmcdrv_ftp_cmdid cmd) |
105 | { |
106 | int rc; |
107 | |
108 | diag_stat_inc(DIAG_STAT_X2C4); |
109 | asm volatile( |
110 | " diag %[addr],%[cmd],0x2c4\n" |
111 | "0: j 2f\n" |
112 | "1: la %[rc],%[err]\n" |
113 | "2:\n" |
114 | EX_TABLE(0b, 1b) |
115 | : [rc] "=d" (rc), "+m" (*fpl) |
116 | : [cmd] "0" (cmd), [addr] "d" (virt_to_phys(fpl)), |
117 | [err] "i" (DIAG_FTP_RET_EPERM) |
118 | : "cc" ); |
119 | |
120 | switch (rc) { |
121 | case DIAG_FTP_RET_OK: |
122 | return 0; |
123 | case DIAG_FTP_RET_EBUSY: |
124 | return -EBUSY; |
125 | case DIAG_FTP_RET_EPERM: |
126 | return -EPERM; |
127 | case DIAG_FTP_RET_EIO: |
128 | default: |
129 | return -EIO; |
130 | } |
131 | } |
132 | |
133 | /** |
134 | * diag_ftp_cmd() - executes a DIAG X'2C4' FTP command, targeting a HMC |
135 | * @ftp: pointer to FTP command specification |
136 | * @fsize: return of file size (or NULL if undesirable) |
137 | * |
138 | * Attention: Notice that this function is not reentrant - so the caller |
139 | * must ensure locking. |
140 | * |
141 | * Return: number of bytes read/written or a (negative) error code |
142 | */ |
143 | ssize_t diag_ftp_cmd(const struct hmcdrv_ftp_cmdspec *ftp, size_t *fsize) |
144 | { |
145 | struct diag_ftp_ldfpl *ldfpl; |
146 | ssize_t len; |
147 | #ifdef DEBUG |
148 | unsigned long start_jiffies; |
149 | |
150 | pr_debug("starting DIAG X'2C4' on '%s', requesting %zd bytes\n" , |
151 | ftp->fname, ftp->len); |
152 | start_jiffies = jiffies; |
153 | #endif |
154 | init_completion(x: &diag_ftp_rx_complete); |
155 | |
156 | ldfpl = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA); |
157 | if (!ldfpl) { |
158 | len = -ENOMEM; |
159 | goto out; |
160 | } |
161 | |
162 | len = strscpy(p: ldfpl->fident, q: ftp->fname, size: sizeof(ldfpl->fident)); |
163 | if (len < 0) { |
164 | len = -EINVAL; |
165 | goto out_free; |
166 | } |
167 | |
168 | ldfpl->transferred = 0; |
169 | ldfpl->fsize = 0; |
170 | ldfpl->offset = ftp->ofs; |
171 | ldfpl->buflen = ftp->len; |
172 | ldfpl->bufaddr = virt_to_phys(address: ftp->buf); |
173 | |
174 | len = diag_ftp_2c4(fpl: ldfpl, cmd: ftp->id); |
175 | if (len) |
176 | goto out_free; |
177 | |
178 | /* |
179 | * There is no way to cancel the running diag X'2C4', the code |
180 | * needs to wait unconditionally until the transfer is complete. |
181 | */ |
182 | wait_for_completion(&diag_ftp_rx_complete); |
183 | |
184 | #ifdef DEBUG |
185 | pr_debug("completed DIAG X'2C4' after %lu ms\n" , |
186 | (jiffies - start_jiffies) * 1000 / HZ); |
187 | pr_debug("status of DIAG X'2C4' is %u, with %lld/%lld bytes\n" , |
188 | diag_ftp_subcode, ldfpl->transferred, ldfpl->fsize); |
189 | #endif |
190 | |
191 | switch (diag_ftp_subcode) { |
192 | case DIAG_FTP_STAT_OK: /* success */ |
193 | len = ldfpl->transferred; |
194 | if (fsize) |
195 | *fsize = ldfpl->fsize; |
196 | break; |
197 | case DIAG_FTP_STAT_LDNPERM: |
198 | len = -EPERM; |
199 | break; |
200 | case DIAG_FTP_STAT_LDRUNS: |
201 | len = -EBUSY; |
202 | break; |
203 | case DIAG_FTP_STAT_LDFAIL: |
204 | len = -ENOENT; /* no such file or media */ |
205 | break; |
206 | default: |
207 | len = -EIO; |
208 | break; |
209 | } |
210 | |
211 | out_free: |
212 | free_page((unsigned long) ldfpl); |
213 | out: |
214 | return len; |
215 | } |
216 | |
217 | /** |
218 | * diag_ftp_startup() - startup of FTP services, when running on z/VM |
219 | * |
220 | * Return: 0 on success, else an (negative) error code |
221 | */ |
222 | int diag_ftp_startup(void) |
223 | { |
224 | int rc; |
225 | |
226 | rc = register_external_irq(EXT_IRQ_CP_SERVICE, diag_ftp_handler); |
227 | if (rc) |
228 | return rc; |
229 | |
230 | irq_subclass_register(IRQ_SUBCLASS_SERVICE_SIGNAL); |
231 | return 0; |
232 | } |
233 | |
234 | /** |
235 | * diag_ftp_shutdown() - shutdown of FTP services, when running on z/VM |
236 | */ |
237 | void diag_ftp_shutdown(void) |
238 | { |
239 | irq_subclass_unregister(IRQ_SUBCLASS_SERVICE_SIGNAL); |
240 | unregister_external_irq(EXT_IRQ_CP_SERVICE, diag_ftp_handler); |
241 | } |
242 | |