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Diffstat (limited to 'arch/s390/kernel/sclp.c')
-rw-r--r--arch/s390/kernel/sclp.c160
1 files changed, 160 insertions, 0 deletions
diff --git a/arch/s390/kernel/sclp.c b/arch/s390/kernel/sclp.c
new file mode 100644
index 000000000000..fa0bdff1d413
--- /dev/null
+++ b/arch/s390/kernel/sclp.c
@@ -0,0 +1,160 @@
+/*
+ * Copyright IBM Corp. 2015
+ * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
+ */
+#include <linux/kernel.h>
+#include <asm/ebcdic.h>
+#include <asm/irq.h>
+#include <asm/lowcore.h>
+#include <asm/processor.h>
+#include <asm/sclp.h>
+
+static char _sclp_work_area[4096] __aligned(PAGE_SIZE);
+
+static void _sclp_wait_int(void)
+{
+ unsigned long cr0, cr0_new, psw_mask, addr;
+ psw_t psw_ext_save, psw_wait;
+
+ __ctl_store(cr0, 0, 0);
+ cr0_new = cr0 | 0x200;
+ __ctl_load(cr0_new, 0, 0);
+
+ psw_ext_save = S390_lowcore.external_new_psw;
+ psw_mask = __extract_psw() & (PSW_MASK_EA | PSW_MASK_BA);
+ S390_lowcore.external_new_psw.mask = psw_mask;
+ psw_wait.mask = psw_mask | PSW_MASK_EXT | PSW_MASK_WAIT;
+ S390_lowcore.ext_int_code = 0;
+
+ do {
+ asm volatile(
+ " larl %[addr],0f\n"
+ " stg %[addr],%[psw_wait_addr]\n"
+ " stg %[addr],%[psw_ext_addr]\n"
+ " lpswe %[psw_wait]\n"
+ "0:\n"
+ : [addr] "=&d" (addr),
+ [psw_wait_addr] "=Q" (psw_wait.addr),
+ [psw_ext_addr] "=Q" (S390_lowcore.external_new_psw.addr)
+ : [psw_wait] "Q" (psw_wait)
+ : "cc", "memory");
+ } while (S390_lowcore.ext_int_code != EXT_IRQ_SERVICE_SIG);
+
+ __ctl_load(cr0, 0, 0);
+ S390_lowcore.external_new_psw = psw_ext_save;
+}
+
+static int _sclp_servc(unsigned int cmd, char *sccb)
+{
+ unsigned int cc;
+
+ do {
+ asm volatile(
+ " .insn rre,0xb2200000,%1,%2\n"
+ " ipm %0\n"
+ : "=d" (cc) : "d" (cmd), "a" (sccb)
+ : "cc", "memory");
+ cc >>= 28;
+ if (cc == 3)
+ return -EINVAL;
+ _sclp_wait_int();
+ } while (cc != 0);
+ return (*(unsigned short *)(sccb + 6) == 0x20) ? 0 : -EIO;
+}
+
+static int _sclp_setup(int disable)
+{
+ static unsigned char init_sccb[] = {
+ 0x00, 0x1c,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x04,
+ 0x80, 0x00, 0x00, 0x00, 0x40, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+ };
+ unsigned int *masks;
+ int rc;
+
+ memcpy(_sclp_work_area, init_sccb, 28);
+ masks = (unsigned int *)(_sclp_work_area + 12);
+ if (disable)
+ memset(masks, 0, 16);
+ /* SCLP write mask */
+ rc = _sclp_servc(0x00780005, _sclp_work_area);
+ if (rc)
+ return rc;
+ if ((masks[0] & masks[3]) != masks[0] ||
+ (masks[1] & masks[2]) != masks[1])
+ return -EIO;
+ return 0;
+}
+
+static int _sclp_print(const char *str)
+{
+ static unsigned char write_head[] = {
+ /* sccb header */
+ 0x00, 0x52, /* 0 */
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 2 */
+ /* evbuf */
+ 0x00, 0x4a, /* 8 */
+ 0x02, 0x00, 0x00, 0x00, /* 10 */
+ /* mdb */
+ 0x00, 0x44, /* 14 */
+ 0x00, 0x01, /* 16 */
+ 0xd4, 0xc4, 0xc2, 0x40, /* 18 */
+ 0x00, 0x00, 0x00, 0x01, /* 22 */
+ /* go */
+ 0x00, 0x38, /* 26 */
+ 0x00, 0x01, /* 28 */
+ 0x00, 0x00, 0x00, 0x00, /* 30 */
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 34 */
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 42 */
+ 0x00, 0x00, 0x00, 0x00, /* 50 */
+ 0x00, 0x00, /* 54 */
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 56 */
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 64 */
+ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 72 */
+ 0x00, 0x00, /* 80 */
+ };
+ static unsigned char write_mto[] = {
+ /* mto */
+ 0x00, 0x0a, /* 0 */
+ 0x00, 0x04, /* 2 */
+ 0x10, 0x00, /* 4 */
+ 0x00, 0x00, 0x00, 0x00 /* 6 */
+ };
+ unsigned char *ptr, ch;
+ unsigned int count;
+
+ memcpy(_sclp_work_area, write_head, sizeof(write_head));
+ ptr = _sclp_work_area + sizeof(write_head);
+ do {
+ memcpy(ptr, write_mto, sizeof(write_mto));
+ for (count = sizeof(write_mto); (ch = *str++) != 0; count++) {
+ if (ch == 0x0a)
+ break;
+ ptr[count] = _ascebc[ch];
+ }
+ /* Update length fields in mto, mdb, evbuf and sccb */
+ *(unsigned short *) ptr = count;
+ *(unsigned short *)(_sclp_work_area + 14) += count;
+ *(unsigned short *)(_sclp_work_area + 8) += count;
+ *(unsigned short *)(_sclp_work_area + 0) += count;
+ ptr += count;
+ } while (ch != 0);
+
+ /* SCLP write data */
+ return _sclp_servc(0x00760005, _sclp_work_area);
+}
+
+int _sclp_print_early(const char *str)
+{
+ int rc;
+
+ rc = _sclp_setup(0);
+ if (rc)
+ return rc;
+ rc = _sclp_print(str);
+ if (rc)
+ return rc;
+ return _sclp_setup(1);
+}