linux/arch/s390/include/asm/lowcore.h
Martin Schwidefsky 6e2ef5e4f6 s390/time: add support for the TOD clock epoch extension
The TOD epoch extension adds 8 epoch bits to the TOD clock to provide
a continuous clock after 2042/09/17. The store-clock-extended (STCKE)
instruction will store the epoch index in the first byte of the
16 bytes stored by the instruction. The read_boot_clock64 and the
read_presistent_clock64 functions need to take the additional bits
into account to give the correct result after 2042/09/17.

The clock-comparator register will stay 64 bit wide. The comparison
of the clock-comparator with the TOD clock is limited to bytes
1 to 8 of the extended TOD format. To deal with the overflow problem
due to an epoch change the clock-comparator sign control in CR0 can
be used to switch the comparison of the 64-bit TOD clock with the
clock-comparator to a signed comparison.

The decision between the signed vs. unsigned clock-comparator
comparisons is done at boot time. Only if the TOD clock is in the
second half of a 142 year epoch the signed comparison is used.
This solves the epoch overflow issue as long as the machine is
booted at least once in an epoch.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-07-26 08:25:14 +02:00

206 lines
6.2 KiB
C

/*
* Copyright IBM Corp. 1999, 2012
* Author(s): Hartmut Penner <hp@de.ibm.com>,
* Martin Schwidefsky <schwidefsky@de.ibm.com>,
* Denis Joseph Barrow,
*/
#ifndef _ASM_S390_LOWCORE_H
#define _ASM_S390_LOWCORE_H
#include <linux/types.h>
#include <asm/ptrace.h>
#include <asm/cpu.h>
#include <asm/types.h>
#define LC_ORDER 1
#define LC_PAGES 2
struct lowcore {
__u8 pad_0x0000[0x0014-0x0000]; /* 0x0000 */
__u32 ipl_parmblock_ptr; /* 0x0014 */
__u8 pad_0x0018[0x0080-0x0018]; /* 0x0018 */
__u32 ext_params; /* 0x0080 */
__u16 ext_cpu_addr; /* 0x0084 */
__u16 ext_int_code; /* 0x0086 */
__u16 svc_ilc; /* 0x0088 */
__u16 svc_code; /* 0x008a */
__u16 pgm_ilc; /* 0x008c */
__u16 pgm_code; /* 0x008e */
__u32 data_exc_code; /* 0x0090 */
__u16 mon_class_num; /* 0x0094 */
__u8 per_code; /* 0x0096 */
__u8 per_atmid; /* 0x0097 */
__u64 per_address; /* 0x0098 */
__u8 exc_access_id; /* 0x00a0 */
__u8 per_access_id; /* 0x00a1 */
__u8 op_access_id; /* 0x00a2 */
__u8 ar_mode_id; /* 0x00a3 */
__u8 pad_0x00a4[0x00a8-0x00a4]; /* 0x00a4 */
__u64 trans_exc_code; /* 0x00a8 */
__u64 monitor_code; /* 0x00b0 */
__u16 subchannel_id; /* 0x00b8 */
__u16 subchannel_nr; /* 0x00ba */
__u32 io_int_parm; /* 0x00bc */
__u32 io_int_word; /* 0x00c0 */
__u8 pad_0x00c4[0x00c8-0x00c4]; /* 0x00c4 */
__u32 stfl_fac_list; /* 0x00c8 */
__u8 pad_0x00cc[0x00e8-0x00cc]; /* 0x00cc */
__u64 mcck_interruption_code; /* 0x00e8 */
__u8 pad_0x00f0[0x00f4-0x00f0]; /* 0x00f0 */
__u32 external_damage_code; /* 0x00f4 */
__u64 failing_storage_address; /* 0x00f8 */
__u8 pad_0x0100[0x0110-0x0100]; /* 0x0100 */
__u64 breaking_event_addr; /* 0x0110 */
__u8 pad_0x0118[0x0120-0x0118]; /* 0x0118 */
psw_t restart_old_psw; /* 0x0120 */
psw_t external_old_psw; /* 0x0130 */
psw_t svc_old_psw; /* 0x0140 */
psw_t program_old_psw; /* 0x0150 */
psw_t mcck_old_psw; /* 0x0160 */
psw_t io_old_psw; /* 0x0170 */
__u8 pad_0x0180[0x01a0-0x0180]; /* 0x0180 */
psw_t restart_psw; /* 0x01a0 */
psw_t external_new_psw; /* 0x01b0 */
psw_t svc_new_psw; /* 0x01c0 */
psw_t program_new_psw; /* 0x01d0 */
psw_t mcck_new_psw; /* 0x01e0 */
psw_t io_new_psw; /* 0x01f0 */
/* Save areas. */
__u64 save_area_sync[8]; /* 0x0200 */
__u64 save_area_async[8]; /* 0x0240 */
__u64 save_area_restart[1]; /* 0x0280 */
/* CPU flags. */
__u64 cpu_flags; /* 0x0288 */
/* Return psws. */
psw_t return_psw; /* 0x0290 */
psw_t return_mcck_psw; /* 0x02a0 */
/* CPU accounting and timing values. */
__u64 sync_enter_timer; /* 0x02b0 */
__u64 async_enter_timer; /* 0x02b8 */
__u64 mcck_enter_timer; /* 0x02c0 */
__u64 exit_timer; /* 0x02c8 */
__u64 user_timer; /* 0x02d0 */
__u64 guest_timer; /* 0x02d8 */
__u64 system_timer; /* 0x02e0 */
__u64 hardirq_timer; /* 0x02e8 */
__u64 softirq_timer; /* 0x02f0 */
__u64 steal_timer; /* 0x02f8 */
__u64 last_update_timer; /* 0x0300 */
__u64 last_update_clock; /* 0x0308 */
__u64 int_clock; /* 0x0310 */
__u64 mcck_clock; /* 0x0318 */
__u64 clock_comparator; /* 0x0320 */
__u64 boot_clock[2]; /* 0x0328 */
/* Current process. */
__u64 current_task; /* 0x0338 */
__u64 kernel_stack; /* 0x0340 */
/* Interrupt, panic and restart stack. */
__u64 async_stack; /* 0x0348 */
__u64 panic_stack; /* 0x0350 */
__u64 restart_stack; /* 0x0358 */
/* Restart function and parameter. */
__u64 restart_fn; /* 0x0360 */
__u64 restart_data; /* 0x0368 */
__u64 restart_source; /* 0x0370 */
/* Address space pointer. */
__u64 kernel_asce; /* 0x0378 */
__u64 user_asce; /* 0x0380 */
/*
* The lpp and current_pid fields form a
* 64-bit value that is set as program
* parameter with the LPP instruction.
*/
__u32 lpp; /* 0x0388 */
__u32 current_pid; /* 0x038c */
/* SMP info area */
__u32 cpu_nr; /* 0x0390 */
__u32 softirq_pending; /* 0x0394 */
__u64 percpu_offset; /* 0x0398 */
__u64 vdso_per_cpu_data; /* 0x03a0 */
__u64 machine_flags; /* 0x03a8 */
__u32 preempt_count; /* 0x03b0 */
__u8 pad_0x03b4[0x03b8-0x03b4]; /* 0x03b4 */
__u64 gmap; /* 0x03b8 */
__u32 spinlock_lockval; /* 0x03c0 */
__u32 fpu_flags; /* 0x03c4 */
__u8 pad_0x03c8[0x0400-0x03c8]; /* 0x03c8 */
/* Per cpu primary space access list */
__u32 paste[16]; /* 0x0400 */
__u8 pad_0x04c0[0x0e00-0x0440]; /* 0x0440 */
/*
* 0xe00 contains the address of the IPL Parameter Information
* block. Dump tools need IPIB for IPL after dump.
* Note: do not change the position of any fields in 0x0e00-0x0f00
*/
__u64 ipib; /* 0x0e00 */
__u32 ipib_checksum; /* 0x0e08 */
__u64 vmcore_info; /* 0x0e0c */
__u8 pad_0x0e14[0x0e18-0x0e14]; /* 0x0e14 */
__u64 os_info; /* 0x0e18 */
__u8 pad_0x0e20[0x0f00-0x0e20]; /* 0x0e20 */
/* Extended facility list */
__u64 stfle_fac_list[32]; /* 0x0f00 */
__u8 pad_0x1000[0x11b0-0x1000]; /* 0x1000 */
/* Pointer to the machine check extended save area */
__u64 mcesad; /* 0x11b0 */
/* 64 bit extparam used for pfault/diag 250: defined by architecture */
__u64 ext_params2; /* 0x11B8 */
__u8 pad_0x11c0[0x1200-0x11C0]; /* 0x11C0 */
/* CPU register save area: defined by architecture */
__u64 floating_pt_save_area[16]; /* 0x1200 */
__u64 gpregs_save_area[16]; /* 0x1280 */
psw_t psw_save_area; /* 0x1300 */
__u8 pad_0x1310[0x1318-0x1310]; /* 0x1310 */
__u32 prefixreg_save_area; /* 0x1318 */
__u32 fpt_creg_save_area; /* 0x131c */
__u8 pad_0x1320[0x1324-0x1320]; /* 0x1320 */
__u32 tod_progreg_save_area; /* 0x1324 */
__u32 cpu_timer_save_area[2]; /* 0x1328 */
__u32 clock_comp_save_area[2]; /* 0x1330 */
__u8 pad_0x1338[0x1340-0x1338]; /* 0x1338 */
__u32 access_regs_save_area[16]; /* 0x1340 */
__u64 cregs_save_area[16]; /* 0x1380 */
__u8 pad_0x1400[0x1800-0x1400]; /* 0x1400 */
/* Transaction abort diagnostic block */
__u8 pgm_tdb[256]; /* 0x1800 */
__u8 pad_0x1900[0x2000-0x1900]; /* 0x1900 */
} __packed;
#define S390_lowcore (*((struct lowcore *) 0))
extern struct lowcore *lowcore_ptr[];
static inline void set_prefix(__u32 address)
{
asm volatile("spx %0" : : "m" (address) : "memory");
}
static inline __u32 store_prefix(void)
{
__u32 address;
asm volatile("stpx %0" : "=m" (address));
return address;
}
#endif /* _ASM_S390_LOWCORE_H */