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 #include <asm/io.h> 20 21 static DEFINE_SPINLOCK(cpcmd_lock); 22 static char cpcmd_buf[241]; 23 24 /* 25 * __cpcmd has some restrictions over cpcmd 26 * - the response buffer must reside below 2GB (if any) 27 * - __cpcmd is unlocked and therefore not SMP-safe 28 */ 29 int __cpcmd(const char *cmd, char *response, int rlen, int *response_code) 30 { 31 unsigned cmdlen; 32 int return_code, return_len; 33 34 cmdlen = strlen(cmd); 35 BUG_ON(cmdlen > 240); 36 memcpy(cpcmd_buf, cmd, cmdlen); 37 ASCEBC(cpcmd_buf, cmdlen); 38 39 if (response != NULL && rlen > 0) { 40 register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf; 41 register unsigned long reg3 asm ("3") = (addr_t) response; 42 register unsigned long reg4 asm ("4") = cmdlen | 0x40000000L; 43 register unsigned long reg5 asm ("5") = rlen; 44 45 memset(response, 0, rlen); 46 asm volatile( 47 #ifndef CONFIG_64BIT 48 " diag %2,%0,0x8\n" 49 " brc 8,1f\n" 50 " ar %1,%4\n" 51 #else /* CONFIG_64BIT */ 52 " sam31\n" 53 " diag %2,%0,0x8\n" 54 " sam64\n" 55 " brc 8,1f\n" 56 " agr %1,%4\n" 57 #endif /* CONFIG_64BIT */ 58 "1:\n" 59 : "+d" (reg4), "+d" (reg5) 60 : "d" (reg2), "d" (reg3), "d" (rlen) : "cc"); 61 return_code = (int) reg4; 62 return_len = (int) reg5; 63 EBCASC(response, rlen); 64 } else { 65 register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf; 66 register unsigned long reg3 asm ("3") = cmdlen; 67 return_len = 0; 68 asm volatile( 69 #ifndef CONFIG_64BIT 70 " diag %1,%0,0x8\n" 71 #else /* CONFIG_64BIT */ 72 " sam31\n" 73 " diag %1,%0,0x8\n" 74 " sam64\n" 75 #endif /* CONFIG_64BIT */ 76 : "+d" (reg3) : "d" (reg2) : "cc"); 77 return_code = (int) reg3; 78 } 79 if (response_code != NULL) 80 *response_code = return_code; 81 return return_len; 82 } 83 84 EXPORT_SYMBOL(__cpcmd); 85 86 int cpcmd(const char *cmd, char *response, int rlen, int *response_code) 87 { 88 char *lowbuf; 89 int len; 90 unsigned long flags; 91 92 if ((virt_to_phys(response) != (unsigned long) response) || 93 (((unsigned long)response + rlen) >> 31)) { 94 lowbuf = kmalloc(rlen, GFP_KERNEL | GFP_DMA); 95 if (!lowbuf) { 96 printk(KERN_WARNING 97 "cpcmd: could not allocate response buffer\n"); 98 return -ENOMEM; 99 } 100 spin_lock_irqsave(&cpcmd_lock, flags); 101 len = __cpcmd(cmd, lowbuf, rlen, response_code); 102 spin_unlock_irqrestore(&cpcmd_lock, flags); 103 memcpy(response, lowbuf, rlen); 104 kfree(lowbuf); 105 } else { 106 spin_lock_irqsave(&cpcmd_lock, flags); 107 len = __cpcmd(cmd, response, rlen, response_code); 108 spin_unlock_irqrestore(&cpcmd_lock, flags); 109 } 110 return len; 111 } 112 113 EXPORT_SYMBOL(cpcmd); 114