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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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 | /* * arch/s390/kernel/cpcmd.c * * 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/module.h> #include <linux/slab.h> #include <linux/spinlock.h> #include <linux/stddef.h> #include <linux/string.h> #include <asm/ebcdic.h> #include <asm/cpcmd.h> #include <asm/system.h> #include <asm/io.h> static DEFINE_SPINLOCK(cpcmd_lock); static char cpcmd_buf[241]; static int diag8_noresponse(int cmdlen) { register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf; register unsigned long reg3 asm ("3") = cmdlen; asm volatile( #ifndef CONFIG_64BIT " diag %1,%0,0x8\n" #else /* CONFIG_64BIT */ " sam31\n" " diag %1,%0,0x8\n" " sam64\n" #endif /* CONFIG_64BIT */ : "+d" (reg3) : "d" (reg2) : "cc"); return reg3; } static int diag8_response(int cmdlen, char *response, int *rlen) { register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf; register unsigned long reg3 asm ("3") = (addr_t) response; register unsigned long reg4 asm ("4") = cmdlen | 0x40000000L; register unsigned long reg5 asm ("5") = *rlen; asm volatile( #ifndef CONFIG_64BIT " diag %2,%0,0x8\n" " brc 8,1f\n" " ar %1,%4\n" #else /* CONFIG_64BIT */ " sam31\n" " diag %2,%0,0x8\n" " sam64\n" " brc 8,1f\n" " agr %1,%4\n" #endif /* CONFIG_64BIT */ "1:\n" : "+d" (reg4), "+d" (reg5) : "d" (reg2), "d" (reg3), "d" (*rlen) : "cc"); *rlen = reg5; return reg4; } /* * __cpcmd has some restrictions over cpcmd * - the response buffer must reside below 2GB (if any) * - __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); 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) { char *lowbuf; int len; unsigned long flags; if ((virt_to_phys(response) != (unsigned long) response) || (((unsigned long)response + rlen) >> 31)) { lowbuf = kmalloc(rlen, GFP_KERNEL | GFP_DMA); if (!lowbuf) { pr_warning("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); |