1 /* 2 * arch/s390/kernel/cpcmd.c 3 * 4 * S390 version 5 * Copyright (C) 1999,2005 IBM Deutschland Entwicklung GmbH, IBM Corporation 6 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com), 7 * Christian Borntraeger (cborntra@de.ibm.com), 8 */ 9 10 #include <linux/kernel.h> 11 #include <linux/module.h> 12 #include <linux/slab.h> 13 #include <linux/spinlock.h> 14 #include <linux/stddef.h> 15 #include <linux/string.h> 16 #include <asm/ebcdic.h> 17 #include <asm/cpcmd.h> 18 #include <asm/system.h> 19 20 static DEFINE_SPINLOCK(cpcmd_lock); 21 static char cpcmd_buf[241]; 22 23 /* 24 * __cpcmd has some restrictions over cpcmd 25 * - the response buffer must reside below 2GB (if any) 26 * - __cpcmd is unlocked and therefore not SMP-safe 27 */ 28 int __cpcmd(const char *cmd, char *response, int rlen, int *response_code) 29 { 30 unsigned cmdlen; 31 int return_code, return_len; 32 33 cmdlen = strlen(cmd); 34 BUG_ON(cmdlen > 240); 35 memcpy(cpcmd_buf, cmd, cmdlen); 36 ASCEBC(cpcmd_buf, cmdlen); 37 38 if (response != NULL && rlen > 0) { 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 memset(response, 0, rlen); 45 asm volatile( 46 #ifndef CONFIG_64BIT 47 " diag %2,%0,0x8\n" 48 " brc 8,1f\n" 49 " ar %1,%4\n" 50 #else /* CONFIG_64BIT */ 51 " sam31\n" 52 " diag %2,%0,0x8\n" 53 " sam64\n" 54 " brc 8,1f\n" 55 " agr %1,%4\n" 56 #endif /* CONFIG_64BIT */ 57 "1:\n" 58 : "+d" (reg4), "+d" (reg5) 59 : "d" (reg2), "d" (reg3), "d" (rlen) : "cc"); 60 return_code = (int) reg4; 61 return_len = (int) reg5; 62 EBCASC(response, rlen); 63 } else { 64 register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf; 65 register unsigned long reg3 asm ("3") = cmdlen; 66 return_len = 0; 67 asm volatile( 68 #ifndef CONFIG_64BIT 69 " diag %1,%0,0x8\n" 70 #else /* CONFIG_64BIT */ 71 " sam31\n" 72 " diag %1,%0,0x8\n" 73 " sam64\n" 74 #endif /* CONFIG_64BIT */ 75 : "+d" (reg3) : "d" (reg2) : "cc"); 76 return_code = (int) reg3; 77 } 78 if (response_code != NULL) 79 *response_code = return_code; 80 return return_len; 81 } 82 83 EXPORT_SYMBOL(__cpcmd); 84 85 int cpcmd(const char *cmd, char *response, int rlen, int *response_code) 86 { 87 char *lowbuf; 88 int len; 89 unsigned long flags; 90 91 if ((rlen == 0) || (response == NULL) 92 || !((unsigned long)response >> 31)) { 93 spin_lock_irqsave(&cpcmd_lock, flags); 94 len = __cpcmd(cmd, response, rlen, response_code); 95 spin_unlock_irqrestore(&cpcmd_lock, flags); 96 } 97 else { 98 lowbuf = kmalloc(rlen, GFP_KERNEL | GFP_DMA); 99 if (!lowbuf) { 100 printk(KERN_WARNING 101 "cpcmd: could not allocate response buffer\n"); 102 return -ENOMEM; 103 } 104 spin_lock_irqsave(&cpcmd_lock, flags); 105 len = __cpcmd(cmd, lowbuf, rlen, response_code); 106 spin_unlock_irqrestore(&cpcmd_lock, flags); 107 memcpy(response, lowbuf, rlen); 108 kfree(lowbuf); 109 } 110 return len; 111 } 112 113 EXPORT_SYMBOL(cpcmd); 114