1 /* 2 * S390 version 3 * Copyright IBM Corp. 1999, 2007 4 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com), 5 * Christian Borntraeger (cborntra@de.ibm.com), 6 */ 7 8 #define KMSG_COMPONENT "cpcmd" 9 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt 10 11 #include <linux/kernel.h> 12 #include <linux/export.h> 13 #include <linux/slab.h> 14 #include <linux/spinlock.h> 15 #include <linux/stddef.h> 16 #include <linux/string.h> 17 #include <linux/mm.h> 18 #include <asm/diag.h> 19 #include <asm/ebcdic.h> 20 #include <asm/cpcmd.h> 21 #include <asm/io.h> 22 23 static DEFINE_SPINLOCK(cpcmd_lock); 24 static char cpcmd_buf[241]; 25 26 static int diag8_noresponse(int cmdlen) 27 { 28 register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf; 29 register unsigned long reg3 asm ("3") = cmdlen; 30 31 asm volatile( 32 " diag %1,%0,0x8\n" 33 : "+d" (reg3) : "d" (reg2) : "cc"); 34 return reg3; 35 } 36 37 static int diag8_response(int cmdlen, char *response, int *rlen) 38 { 39 register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf; 40 register unsigned long reg3 asm ("3") = (addr_t) response; 41 register unsigned long reg4 asm ("4") = cmdlen | 0x40000000L; 42 register unsigned long reg5 asm ("5") = *rlen; 43 44 asm volatile( 45 " diag %2,%0,0x8\n" 46 " brc 8,1f\n" 47 " agr %1,%4\n" 48 "1:\n" 49 : "+d" (reg4), "+d" (reg5) 50 : "d" (reg2), "d" (reg3), "d" (*rlen) : "cc"); 51 *rlen = reg5; 52 return reg4; 53 } 54 55 /* 56 * __cpcmd has some restrictions over cpcmd 57 * - __cpcmd is unlocked and therefore not SMP-safe 58 */ 59 int __cpcmd(const char *cmd, char *response, int rlen, int *response_code) 60 { 61 int cmdlen; 62 int rc; 63 int response_len; 64 65 cmdlen = strlen(cmd); 66 BUG_ON(cmdlen > 240); 67 memcpy(cpcmd_buf, cmd, cmdlen); 68 ASCEBC(cpcmd_buf, cmdlen); 69 70 diag_stat_inc(DIAG_STAT_X008); 71 if (response) { 72 memset(response, 0, rlen); 73 response_len = rlen; 74 rc = diag8_response(cmdlen, response, &rlen); 75 EBCASC(response, response_len); 76 } else { 77 rc = diag8_noresponse(cmdlen); 78 } 79 if (response_code) 80 *response_code = rc; 81 return rlen; 82 } 83 EXPORT_SYMBOL(__cpcmd); 84 85 int cpcmd(const char *cmd, char *response, int rlen, int *response_code) 86 { 87 unsigned long flags; 88 char *lowbuf; 89 int len; 90 91 if (is_vmalloc_or_module_addr(response)) { 92 lowbuf = kmalloc(rlen, GFP_KERNEL); 93 if (!lowbuf) { 94 pr_warn("The cpcmd kernel function failed to allocate a response buffer\n"); 95 return -ENOMEM; 96 } 97 spin_lock_irqsave(&cpcmd_lock, flags); 98 len = __cpcmd(cmd, lowbuf, rlen, response_code); 99 spin_unlock_irqrestore(&cpcmd_lock, flags); 100 memcpy(response, lowbuf, rlen); 101 kfree(lowbuf); 102 } else { 103 spin_lock_irqsave(&cpcmd_lock, flags); 104 len = __cpcmd(cmd, response, rlen, response_code); 105 spin_unlock_irqrestore(&cpcmd_lock, flags); 106 } 107 return len; 108 } 109 EXPORT_SYMBOL(cpcmd); 110