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- // SPDX-License-Identifier: GPL-2.0
- /*
- * S390 version
- * Copyright IBM Corp. 1999, 2007
- * Author(s): Martin Schwidefsky ([email protected]),
- * Christian Borntraeger ([email protected]),
- */
- #define KMSG_COMPONENT "cpcmd"
- #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
- #include <linux/kernel.h>
- #include <linux/export.h>
- #include <linux/slab.h>
- #include <linux/spinlock.h>
- #include <linux/stddef.h>
- #include <linux/string.h>
- #include <linux/mm.h>
- #include <asm/diag.h>
- #include <asm/ebcdic.h>
- #include <asm/cpcmd.h>
- #include <asm/io.h>
- static DEFINE_SPINLOCK(cpcmd_lock);
- static char cpcmd_buf[241];
- static int diag8_noresponse(int cmdlen)
- {
- asm volatile(
- " diag %[rx],%[ry],0x8\n"
- : [ry] "+&d" (cmdlen)
- : [rx] "d" (__pa(cpcmd_buf))
- : "cc");
- return cmdlen;
- }
- static int diag8_response(int cmdlen, char *response, int *rlen)
- {
- union register_pair rx, ry;
- int cc;
- rx.even = __pa(cpcmd_buf);
- rx.odd = __pa(response);
- ry.even = cmdlen | 0x40000000L;
- ry.odd = *rlen;
- asm volatile(
- " diag %[rx],%[ry],0x8\n"
- " ipm %[cc]\n"
- " srl %[cc],28\n"
- : [cc] "=&d" (cc), [ry] "+&d" (ry.pair)
- : [rx] "d" (rx.pair)
- : "cc");
- if (cc)
- *rlen += ry.odd;
- else
- *rlen = ry.odd;
- return ry.even;
- }
- /*
- * __cpcmd has some restrictions over cpcmd
- * - __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);
- diag_stat_inc(DIAG_STAT_X008);
- 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)
- {
- unsigned long flags;
- char *lowbuf;
- int len;
- if (is_vmalloc_or_module_addr(response)) {
- lowbuf = kmalloc(rlen, GFP_KERNEL);
- if (!lowbuf) {
- pr_warn("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);
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