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1// SPDX-License-Identifier: GPL-2.02/*3 * DIAGNOSE X'2C4' instruction based HMC FTP services, useable on z/VM4 *5 * Copyright IBM Corp. 20136 * Author(s): Ralf Hoppe (rhoppe@de.ibm.com)7 *8 */9 10#define KMSG_COMPONENT "hmcdrv"11#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt12 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 buffer47 * @offset: dir/file offset48 * @intparm: interruption parameter (unused)49 * @transferred: bytes transferred50 * @fsize: file size, filled on GET51 * @failaddr: failing address52 * @spare: padding53 * @fident: file name - ASCII54 */55struct 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 67static DECLARE_COMPLETION(diag_ftp_rx_complete);68static int diag_ftp_subcode;69 70/**71 * diag_ftp_handler() - FTP services IRQ handler72 * @extirq: external interrupt (sub-) code73 * @param32: 32-bit interruption parameter from &struct diag_ftp_ldfpl74 * @param64: unused (for 64-bit interrupt parameters)75 */76static 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 call90 * @fpl: pointer to prepared LDFPL91 * @cmd: FTP command to be executed92 *93 * Performs a DIAGNOSE X'2C4' call with (input/output) FTP parameter list94 * @fpl and FTP function code @cmd. In case of an error the function does95 * nothing and returns an (negative) error code.96 *97 * Notes:98 * 1. This function only initiates a transfer, so the caller must wait99 * 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 aligned102 */103static 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 HMC135 * @ftp: pointer to FTP command specification136 * @fsize: return of file size (or NULL if undesirable)137 *138 * Attention: Notice that this function is not reentrant - so the caller139 * must ensure locking.140 *141 * Return: number of bytes read/written or a (negative) error code142 */143ssize_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 DEBUG148 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#endif154 init_completion(&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(ldfpl->fident, ftp->fname, 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(ftp->buf);173 174 len = diag_ftp_2c4(ldfpl, ftp->id);175 if (len)176 goto out_free;177 178 /*179 * There is no way to cancel the running diag X'2C4', the code180 * needs to wait unconditionally until the transfer is complete.181 */182 wait_for_completion(&diag_ftp_rx_complete);183 184#ifdef DEBUG185 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#endif190 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 211out_free:212 free_page((unsigned long) ldfpl);213out:214 return len;215}216 217/**218 * diag_ftp_startup() - startup of FTP services, when running on z/VM219 *220 * Return: 0 on success, else an (negative) error code221 */222int 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/VM236 */237void 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