diff options
Diffstat (limited to 'arch/s390/kernel/sclp.c')
| -rw-r--r-- | arch/s390/kernel/sclp.c | 160 |
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); +} |