From: Michael Holzheu <holzheu@xxxxxxxxxxxxxxxxxx> With this patch a new S390 shutdown trigger "restart" is added. If under z/VM "systerm restart" is entered or under the HMC the "PSW restart" button is pressed, the PSW located at 0 (31 bit) or 0x1a0 (64 bit) bit is loaded. Now we execute do_restart() that processes the restart action that is defined under /sys/firmware/shutdown_actions/on_restart. Currently the following actions are possible: reipl (default), stop, vmcmd, dump, and dump_reipl. Signed-off-by: Michael Holzheu <holzheu@xxxxxxxxxxxxxxxxxx> --- arch/s390/include/asm/lowcore.h | 11 +++++++++-- arch/s390/include/asm/system.h | 1 + arch/s390/kernel/asm-offsets.c | 1 + arch/s390/kernel/entry.S | 28 ++++++++++++++++++++++++++++ arch/s390/kernel/entry64.S | 20 ++++++++++++++++++++ arch/s390/kernel/ipl.c | 39 ++++++++++++++++++++++++++++++++++++++- arch/s390/kernel/setup.c | 24 +++++++++++++++++++++++- arch/s390/kernel/smp.c | 8 ++++++++ arch/s390/mm/maccess.c | 16 ++++++++++++++++ 9 files changed, 144 insertions(+), 4 deletions(-) --- a/arch/s390/include/asm/lowcore.h +++ b/arch/s390/include/asm/lowcore.h @@ -18,6 +18,7 @@ void system_call(void); void pgm_check_handler(void); void mcck_int_handler(void); void io_int_handler(void); +void psw_restart_int_handler(void); #ifdef CONFIG_32BIT @@ -150,7 +151,10 @@ struct _lowcore { */ __u32 ipib; /* 0x0e00 */ __u32 ipib_checksum; /* 0x0e04 */ - __u8 pad_0x0e08[0x0f00-0x0e08]; /* 0x0e08 */ + + /* 64 bit save area */ + __u64 save_area_64; /* 0x0e08 */ + __u8 pad_0x0e10[0x0f00-0x0e10]; /* 0x0e10 */ /* Extended facility list */ __u64 stfle_fac_list[32]; /* 0x0f00 */ @@ -286,7 +290,10 @@ struct _lowcore { */ __u64 ipib; /* 0x0e00 */ __u32 ipib_checksum; /* 0x0e08 */ - __u8 pad_0x0e0c[0x0f00-0x0e0c]; /* 0x0e0c */ + + /* 64 bit save area */ + __u64 save_area_64; /* 0x0e0c */ + __u8 pad_0x0e14[0x0f00-0x0e14]; /* 0x0e14 */ /* Extended facility list */ __u64 stfle_fac_list[32]; /* 0x0f00 */ --- a/arch/s390/include/asm/system.h +++ b/arch/s390/include/asm/system.h @@ -113,6 +113,7 @@ extern void pfault_fini(void); extern void cmma_init(void); extern int memcpy_real(void *, void *, size_t); +extern void copy_to_absolute_zero(void *dest, void *src, size_t count); #define finish_arch_switch(prev) do { \ set_fs(current->thread.mm_segment); \ --- a/arch/s390/kernel/asm-offsets.c +++ b/arch/s390/kernel/asm-offsets.c @@ -142,6 +142,7 @@ int main(void) DEFINE(__LC_FPREGS_SAVE_AREA, offsetof(struct _lowcore, floating_pt_save_area)); DEFINE(__LC_GPREGS_SAVE_AREA, offsetof(struct _lowcore, gpregs_save_area)); DEFINE(__LC_CREGS_SAVE_AREA, offsetof(struct _lowcore, cregs_save_area)); + DEFINE(__LC_SAVE_AREA_64, offsetof(struct _lowcore, save_area_64)); #ifdef CONFIG_32BIT DEFINE(SAVE_AREA_BASE, offsetof(struct _lowcore, extended_save_area_addr)); #else /* CONFIG_32BIT */ --- a/arch/s390/kernel/entry.S +++ b/arch/s390/kernel/entry.S @@ -849,6 +849,34 @@ restart_crash: restart_go: #endif +# +# PSW restart interrupt handler +# +ENTRY(psw_restart_int_handler) + st %r15,__LC_SAVE_AREA_64(%r0) # save r15 + basr %r15,0 +0: l %r15,.Lrestart_stack-0b(%r15) # load restart stack + l %r15,0(%r15) + ahi %r15,-SP_SIZE # make room for pt_regs + stm %r0,%r14,SP_R0(%r15) # store gprs %r0-%r14 to stack + mvc SP_R15(4,%r15),__LC_SAVE_AREA_64(%r0)# store saved %r15 to stack + mvc SP_PSW(8,%r15),__LC_RST_OLD_PSW(%r0) # store restart old psw + xc __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # set backchain to 0 + basr %r14,0 +1: l %r14,.Ldo_restart-1b(%r14) + basr %r14,%r14 + + basr %r14,0 # load disabled wait PSW if +2: lpsw restart_psw_crash-2b(%r14) # do_restart returns + .align 4 +.Ldo_restart: + .long do_restart +.Lrestart_stack: + .long restart_stack + .align 8 +restart_psw_crash: + .long 0x000a0000,0x00000000 + restart_psw_crash + .section .kprobes.text, "ax" #ifdef CONFIG_CHECK_STACK --- a/arch/s390/kernel/entry64.S +++ b/arch/s390/kernel/entry64.S @@ -865,6 +865,26 @@ restart_crash: restart_go: #endif +# +# PSW restart interrupt handler +# +ENTRY(psw_restart_int_handler) + stg %r15,__LC_SAVE_AREA_64(%r0) # save r15 + larl %r15,restart_stack # load restart stack + lg %r15,0(%r15) + aghi %r15,-SP_SIZE # make room for pt_regs + stmg %r0,%r14,SP_R0(%r15) # store gprs %r0-%r14 to stack + mvc SP_R15(8,%r15),__LC_SAVE_AREA_64(%r0)# store saved %r15 to stack + mvc SP_PSW(16,%r15),__LC_RST_OLD_PSW(%r0)# store restart old psw + xc __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) # set backchain to 0 + brasl %r14,do_restart + + larl %r14,restart_psw_crash # load disabled wait PSW if + lpswe 0(%r14) # do_restart returns + .align 8 +restart_psw_crash: + .quad 0x0002000080000000,0x0000000000000000 + restart_psw_crash + .section .kprobes.text, "ax" #ifdef CONFIG_CHECK_STACK --- a/arch/s390/kernel/ipl.c +++ b/arch/s390/kernel/ipl.c @@ -45,11 +45,13 @@ * - halt * - power off * - reipl + * - restart */ #define ON_PANIC_STR "on_panic" #define ON_HALT_STR "on_halt" #define ON_POFF_STR "on_poff" #define ON_REIPL_STR "on_reboot" +#define ON_RESTART_STR "on_restart" struct shutdown_action; struct shutdown_trigger { @@ -1544,17 +1546,20 @@ static char vmcmd_on_reboot[128]; static char vmcmd_on_panic[128]; static char vmcmd_on_halt[128]; static char vmcmd_on_poff[128]; +static char vmcmd_on_restart[128]; DEFINE_IPL_ATTR_STR_RW(vmcmd, on_reboot, "%s\n", "%s\n", vmcmd_on_reboot); DEFINE_IPL_ATTR_STR_RW(vmcmd, on_panic, "%s\n", "%s\n", vmcmd_on_panic); DEFINE_IPL_ATTR_STR_RW(vmcmd, on_halt, "%s\n", "%s\n", vmcmd_on_halt); DEFINE_IPL_ATTR_STR_RW(vmcmd, on_poff, "%s\n", "%s\n", vmcmd_on_poff); +DEFINE_IPL_ATTR_STR_RW(vmcmd, on_restart, "%s\n", "%s\n", vmcmd_on_restart); static struct attribute *vmcmd_attrs[] = { &sys_vmcmd_on_reboot_attr.attr, &sys_vmcmd_on_panic_attr.attr, &sys_vmcmd_on_halt_attr.attr, &sys_vmcmd_on_poff_attr.attr, + &sys_vmcmd_on_restart_attr.attr, NULL, }; @@ -1576,6 +1581,8 @@ static void vmcmd_run(struct shutdown_tr cmd = vmcmd_on_halt; else if (strcmp(trigger->name, ON_POFF_STR) == 0) cmd = vmcmd_on_poff; + else if (strcmp(trigger->name, ON_RESTART_STR) == 0) + cmd = vmcmd_on_restart; else return; @@ -1707,6 +1714,34 @@ static void do_panic(void) stop_run(&on_panic_trigger); } +/* on restart */ + +static struct shutdown_trigger on_restart_trigger = {ON_RESTART_STR, + &reipl_action}; + +static ssize_t on_restart_show(struct kobject *kobj, + struct kobj_attribute *attr, char *page) +{ + return sprintf(page, "%s\n", on_restart_trigger.action->name); +} + +static ssize_t on_restart_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t len) +{ + return set_trigger(buf, &on_restart_trigger, len); +} + +static struct kobj_attribute on_restart_attr = + __ATTR(on_restart, 0644, on_restart_show, on_restart_store); + +void do_restart(void) +{ + smp_send_stop(); + on_restart_trigger.action->fn(&on_restart_trigger); + stop_run(&on_restart_trigger); +} + /* on halt */ static struct shutdown_trigger on_halt_trigger = {ON_HALT_STR, &stop_action}; @@ -1783,7 +1818,9 @@ static void __init shutdown_triggers_ini if (sysfs_create_file(&shutdown_actions_kset->kobj, &on_poff_attr.attr)) goto fail; - + if (sysfs_create_file(&shutdown_actions_kset->kobj, + &on_restart_attr.attr)) + goto fail; return; fail: panic("shutdown_triggers_init failed\n"); --- a/arch/s390/kernel/setup.c +++ b/arch/s390/kernel/setup.c @@ -346,7 +346,7 @@ setup_lowcore(void) lc = __alloc_bootmem_low(LC_PAGES * PAGE_SIZE, LC_PAGES * PAGE_SIZE, 0); lc->restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY; lc->restart_psw.addr = - PSW_ADDR_AMODE | (unsigned long) restart_int_handler; + PSW_ADDR_AMODE | (unsigned long) psw_restart_int_handler; if (user_mode != HOME_SPACE_MODE) lc->restart_psw.mask |= PSW_ASC_HOME; lc->external_new_psw.mask = psw_kernel_bits; @@ -529,6 +529,27 @@ static void __init setup_memory_end(void memory_end = memory_size; } +void *restart_stack __attribute__((__section__(".data"))); + +/* + * Setup new PSW and allocate stack for PSW restart interrupt + */ +static void __init setup_restart_psw(void) +{ + psw_t psw; + + restart_stack = __alloc_bootmem(ASYNC_SIZE, ASYNC_SIZE, 0); + restart_stack += ASYNC_SIZE; + + /* + * Setup restart PSW for absolute zero lowcore. This is necesary + * if PSW restart is done on an offline CPU that has lowcore zero + */ + psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY; + psw.addr = PSW_ADDR_AMODE | (unsigned long) psw_restart_int_handler; + copy_to_absolute_zero(&S390_lowcore.restart_psw, &psw, sizeof(psw)); +} + static void __init setup_memory(void) { @@ -792,6 +813,7 @@ setup_arch(char **cmdline_p) setup_addressing_mode(); setup_memory(); setup_resources(); + setup_restart_psw(); setup_lowcore(); cpu_init(); --- a/arch/s390/kernel/smp.c +++ b/arch/s390/kernel/smp.c @@ -470,6 +470,11 @@ int __cpuinit start_secondary(void *cpuv ipi_call_unlock(); /* Switch on interrupts */ local_irq_enable(); + __ctl_clear_bit(0, 28); /* Disable lowcore protection */ + S390_lowcore.restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY; + S390_lowcore.restart_psw.addr = + PSW_ADDR_AMODE | (unsigned long) psw_restart_int_handler; + __ctl_set_bit(0, 28); /* Enable lowcore protection */ /* cpu_idle will call schedule for us */ cpu_idle(); return 0; @@ -507,6 +512,9 @@ static int __cpuinit smp_alloc_lowcore(i memset((char *)lowcore + 512, 0, sizeof(*lowcore) - 512); lowcore->async_stack = async_stack + ASYNC_SIZE; lowcore->panic_stack = panic_stack + PAGE_SIZE; + lowcore->restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY; + lowcore->restart_psw.addr = + PSW_ADDR_AMODE | (unsigned long) restart_int_handler; #ifndef CONFIG_64BIT if (MACHINE_HAS_IEEE) { --- a/arch/s390/mm/maccess.c +++ b/arch/s390/mm/maccess.c @@ -85,3 +85,19 @@ int memcpy_real(void *dest, void *src, s arch_local_irq_restore(flags); return rc; } + +/* + * Copy memory to absolute zero + */ +void copy_to_absolute_zero(void *dest, void *src, size_t count) +{ + unsigned long cr0; + + BUG_ON((unsigned long) dest + count >= sizeof(struct _lowcore)); + preempt_disable(); + __ctl_store(cr0, 0, 0); + __ctl_clear_bit(0, 28); /* disable lowcore protection */ + memcpy_real(dest + store_prefix(), src, count); + __ctl_load(cr0, 0, 0); + preempt_enable(); +} -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html