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 */ 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 */ 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 */ 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 */ 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 */ 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