126 lines
3.0 KiB
C
126 lines
3.0 KiB
C
/*
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* arch/s390/kernel/cpcmd.c
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*
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* S390 version
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* Copyright IBM Corp. 1999,2007
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* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
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* Christian Borntraeger (cborntra@de.ibm.com),
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*/
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#define KMSG_COMPONENT "cpcmd"
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#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/spinlock.h>
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#include <linux/stddef.h>
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#include <linux/string.h>
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#include <asm/ebcdic.h>
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#include <asm/cpcmd.h>
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#include <asm/io.h>
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static DEFINE_SPINLOCK(cpcmd_lock);
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static char cpcmd_buf[241];
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static int diag8_noresponse(int cmdlen)
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{
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register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf;
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register unsigned long reg3 asm ("3") = cmdlen;
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asm volatile(
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#ifndef CONFIG_64BIT
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" diag %1,%0,0x8\n"
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#else /* CONFIG_64BIT */
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" sam31\n"
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" diag %1,%0,0x8\n"
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" sam64\n"
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#endif /* CONFIG_64BIT */
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: "+d" (reg3) : "d" (reg2) : "cc");
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return reg3;
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}
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static int diag8_response(int cmdlen, char *response, int *rlen)
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{
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register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf;
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register unsigned long reg3 asm ("3") = (addr_t) response;
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register unsigned long reg4 asm ("4") = cmdlen | 0x40000000L;
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register unsigned long reg5 asm ("5") = *rlen;
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asm volatile(
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#ifndef CONFIG_64BIT
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" diag %2,%0,0x8\n"
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" brc 8,1f\n"
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" ar %1,%4\n"
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#else /* CONFIG_64BIT */
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" sam31\n"
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" diag %2,%0,0x8\n"
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" sam64\n"
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" brc 8,1f\n"
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" agr %1,%4\n"
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#endif /* CONFIG_64BIT */
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"1:\n"
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: "+d" (reg4), "+d" (reg5)
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: "d" (reg2), "d" (reg3), "d" (*rlen) : "cc");
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*rlen = reg5;
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return reg4;
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}
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/*
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* __cpcmd has some restrictions over cpcmd
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* - the response buffer must reside below 2GB (if any)
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* - __cpcmd is unlocked and therefore not SMP-safe
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*/
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int __cpcmd(const char *cmd, char *response, int rlen, int *response_code)
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{
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int cmdlen;
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int rc;
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int response_len;
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cmdlen = strlen(cmd);
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BUG_ON(cmdlen > 240);
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memcpy(cpcmd_buf, cmd, cmdlen);
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ASCEBC(cpcmd_buf, cmdlen);
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if (response) {
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memset(response, 0, rlen);
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response_len = rlen;
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rc = diag8_response(cmdlen, response, &rlen);
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EBCASC(response, response_len);
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} else {
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rc = diag8_noresponse(cmdlen);
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}
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if (response_code)
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*response_code = rc;
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return rlen;
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}
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EXPORT_SYMBOL(__cpcmd);
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int cpcmd(const char *cmd, char *response, int rlen, int *response_code)
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{
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char *lowbuf;
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int len;
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unsigned long flags;
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if ((virt_to_phys(response) != (unsigned long) response) ||
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(((unsigned long)response + rlen) >> 31)) {
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lowbuf = kmalloc(rlen, GFP_KERNEL | GFP_DMA);
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if (!lowbuf) {
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pr_warning("The cpcmd kernel function failed to "
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"allocate a response buffer\n");
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return -ENOMEM;
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}
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spin_lock_irqsave(&cpcmd_lock, flags);
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len = __cpcmd(cmd, lowbuf, rlen, response_code);
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spin_unlock_irqrestore(&cpcmd_lock, flags);
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memcpy(response, lowbuf, rlen);
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kfree(lowbuf);
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} else {
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spin_lock_irqsave(&cpcmd_lock, flags);
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len = __cpcmd(cmd, response, rlen, response_code);
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spin_unlock_irqrestore(&cpcmd_lock, flags);
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}
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return len;
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}
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EXPORT_SYMBOL(cpcmd);
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