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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 | // SPDX-License-Identifier: GPL-2.0 /* * S390 version * Copyright IBM Corp. 1999, 2007 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com), * Christian Borntraeger (cborntra@de.ibm.com), */ #define KMSG_COMPONENT "cpcmd" #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt #include <linux/kernel.h> #include <linux/export.h> #include <linux/slab.h> #include <linux/spinlock.h> #include <linux/stddef.h> #include <linux/string.h> #include <linux/mm.h> #include <linux/io.h> #include <asm/diag.h> #include <asm/ebcdic.h> #include <asm/cpcmd.h> static DEFINE_SPINLOCK(cpcmd_lock); static char cpcmd_buf[241]; static int diag8_noresponse(int cmdlen) { asm volatile( " diag %[rx],%[ry],0x8\n" : [ry] "+&d" (cmdlen) : [rx] "d" (__pa(cpcmd_buf)) : "cc"); return cmdlen; } static int diag8_response(int cmdlen, char *response, int *rlen) { union register_pair rx, ry; int cc; rx.even = __pa(cpcmd_buf); rx.odd = __pa(response); ry.even = cmdlen | 0x40000000L; ry.odd = *rlen; asm volatile( " diag %[rx],%[ry],0x8\n" " ipm %[cc]\n" " srl %[cc],28\n" : [cc] "=&d" (cc), [ry] "+&d" (ry.pair) : [rx] "d" (rx.pair) : "cc"); if (cc) *rlen += ry.odd; else *rlen = ry.odd; return ry.even; } /* * __cpcmd has some restrictions over cpcmd * - __cpcmd is unlocked and therefore not SMP-safe */ int __cpcmd(const char *cmd, char *response, int rlen, int *response_code) { int cmdlen; int rc; int response_len; cmdlen = strlen(cmd); BUG_ON(cmdlen > 240); memcpy(cpcmd_buf, cmd, cmdlen); ASCEBC(cpcmd_buf, cmdlen); diag_stat_inc(DIAG_STAT_X008); if (response) { memset(response, 0, rlen); response_len = rlen; rc = diag8_response(cmdlen, response, &rlen); EBCASC(response, response_len); } else { rc = diag8_noresponse(cmdlen); } if (response_code) *response_code = rc; return rlen; } EXPORT_SYMBOL(__cpcmd); int cpcmd(const char *cmd, char *response, int rlen, int *response_code) { unsigned long flags; char *lowbuf; int len; if (is_vmalloc_or_module_addr(response)) { lowbuf = kmalloc(rlen, GFP_KERNEL); if (!lowbuf) { pr_warn("The cpcmd kernel function failed to allocate a response buffer\n"); return -ENOMEM; } spin_lock_irqsave(&cpcmd_lock, flags); len = __cpcmd(cmd, lowbuf, rlen, response_code); spin_unlock_irqrestore(&cpcmd_lock, flags); memcpy(response, lowbuf, rlen); kfree(lowbuf); } else { spin_lock_irqsave(&cpcmd_lock, flags); len = __cpcmd(cmd, response, rlen, response_code); spin_unlock_irqrestore(&cpcmd_lock, flags); } return len; } EXPORT_SYMBOL(cpcmd); |