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/module.h> 13 #include <linux/slab.h> 14 #include <linux/spinlock.h> 15 #include <linux/stddef.h> 16 #include <linux/string.h> 17 #include <asm/ebcdic.h> 18 #include <asm/cpcmd.h> 19 #include <asm/io.h> 20 21 static DEFINE_SPINLOCK(cpcmd_lock); 22 static char cpcmd_buf[241]; 23 24 static int diag8_noresponse(int cmdlen) 25 { 26 register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf; 27 register unsigned long reg3 asm ("3") = cmdlen; 28 29 asm volatile( 30 #ifndef CONFIG_64BIT 31 " diag %1,%0,0x8\n" 32 #else /* CONFIG_64BIT */ 33 " sam31\n" 34 " diag %1,%0,0x8\n" 35 " sam64\n" 36 #endif /* CONFIG_64BIT */ 37 : "+d" (reg3) : "d" (reg2) : "cc"); 38 return reg3; 39 } 40 41 static int diag8_response(int cmdlen, char *response, int *rlen) 42 { 43 register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf; 44 register unsigned long reg3 asm ("3") = (addr_t) response; 45 register unsigned long reg4 asm ("4") = cmdlen | 0x40000000L; 46 register unsigned long reg5 asm ("5") = *rlen; 47 48 asm volatile( 49 #ifndef CONFIG_64BIT 50 " diag %2,%0,0x8\n" 51 " brc 8,1f\n" 52 " ar %1,%4\n" 53 #else /* CONFIG_64BIT */ 54 " sam31\n" 55 " diag %2,%0,0x8\n" 56 " sam64\n" 57 " brc 8,1f\n" 58 " agr %1,%4\n" 59 #endif /* CONFIG_64BIT */ 60 "1:\n" 61 : "+d" (reg4), "+d" (reg5) 62 : "d" (reg2), "d" (reg3), "d" (*rlen) : "cc"); 63 *rlen = reg5; 64 return reg4; 65 } 66 67 /* 68 * __cpcmd has some restrictions over cpcmd 69 * - the response buffer must reside below 2GB (if any) 70 * - __cpcmd is unlocked and therefore not SMP-safe 71 */ 72 int __cpcmd(const char *cmd, char *response, int rlen, int *response_code) 73 { 74 int cmdlen; 75 int rc; 76 int response_len; 77 78 cmdlen = strlen(cmd); 79 BUG_ON(cmdlen > 240); 80 memcpy(cpcmd_buf, cmd, cmdlen); 81 ASCEBC(cpcmd_buf, cmdlen); 82 83 if (response) { 84 memset(response, 0, rlen); 85 response_len = rlen; 86 rc = diag8_response(cmdlen, response, &rlen); 87 EBCASC(response, response_len); 88 } else { 89 rc = diag8_noresponse(cmdlen); 90 } 91 if (response_code) 92 *response_code = rc; 93 return rlen; 94 } 95 EXPORT_SYMBOL(__cpcmd); 96 97 int cpcmd(const char *cmd, char *response, int rlen, int *response_code) 98 { 99 char *lowbuf; 100 int len; 101 unsigned long flags; 102 103 if ((virt_to_phys(response) != (unsigned long) response) || 104 (((unsigned long)response + rlen) >> 31)) { 105 lowbuf = kmalloc(rlen, GFP_KERNEL | GFP_DMA); 106 if (!lowbuf) { 107 pr_warning("The cpcmd kernel function failed to " 108 "allocate a response buffer\n"); 109 return -ENOMEM; 110 } 111 spin_lock_irqsave(&cpcmd_lock, flags); 112 len = __cpcmd(cmd, lowbuf, rlen, response_code); 113 spin_unlock_irqrestore(&cpcmd_lock, flags); 114 memcpy(response, lowbuf, rlen); 115 kfree(lowbuf); 116 } else { 117 spin_lock_irqsave(&cpcmd_lock, flags); 118 len = __cpcmd(cmd, response, rlen, response_code); 119 spin_unlock_irqrestore(&cpcmd_lock, flags); 120 } 121 return len; 122 } 123 EXPORT_SYMBOL(cpcmd); 124