xmon can be entered via sreset NMI (from a management sreset, or an NMI IPI), which can interrupt OPAL. Add checks to xmon to see if pc or sp are within OPAL memory, and if so, then use OPAL_DEBUG to print the opal stack and return the Linux stack, which can then be dumped by xmon
The OPAL side of this, with sample xmon output is here: https://lists.ozlabs.org/pipermail/skiboot/2018-March/010856.html This could be plumed into the oops printing code as well. Thanks, Nick --- arch/powerpc/include/asm/opal.h | 4 ++++ arch/powerpc/platforms/powernv/opal-wrappers.S | 1 + arch/powerpc/platforms/powernv/opal.c | 5 +++++ arch/powerpc/xmon/xmon.c | 27 ++++++++++++++++++++++++++ 4 files changed, 37 insertions(+) diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h index 12e70fb58700..afcc0c5ed5b0 100644 --- a/arch/powerpc/include/asm/opal.h +++ b/arch/powerpc/include/asm/opal.h @@ -27,6 +27,8 @@ extern struct kobject *opal_kobj; /* /ibm,opal */ extern struct device_node *opal_node; +bool in_opal_text_heap_stack(u64 address); + /* API functions */ int64_t opal_invalid_call(void); int64_t opal_npu_destroy_context(uint64_t phb_id, uint64_t pid, uint64_t bdf); @@ -289,6 +291,8 @@ int opal_sensor_group_clear(u32 group_hndl, int token); s64 opal_signal_system_reset(s32 cpu); +s64 opal_debug(u32 debug_type, u64 r1); + /* Internal functions */ extern int early_init_dt_scan_opal(unsigned long node, const char *uname, int depth, void *data); diff --git a/arch/powerpc/platforms/powernv/opal-wrappers.S b/arch/powerpc/platforms/powernv/opal-wrappers.S index 1b2936ba6040..78b9ae003553 100644 --- a/arch/powerpc/platforms/powernv/opal-wrappers.S +++ b/arch/powerpc/platforms/powernv/opal-wrappers.S @@ -323,3 +323,4 @@ OPAL_CALL(opal_sensor_group_clear, OPAL_SENSOR_GROUP_CLEAR); OPAL_CALL(opal_npu_spa_setup, OPAL_NPU_SPA_SETUP); OPAL_CALL(opal_npu_spa_clear_cache, OPAL_NPU_SPA_CLEAR_CACHE); OPAL_CALL(opal_npu_tl_set, OPAL_NPU_TL_SET); +OPAL_CALL(opal_debug, 167); diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c index c15182765ff5..0b7ff5fb18f8 100644 --- a/arch/powerpc/platforms/powernv/opal.c +++ b/arch/powerpc/platforms/powernv/opal.c @@ -64,6 +64,11 @@ static struct atomic_notifier_head opal_msg_notifier_head[OPAL_MSG_TYPE_MAX]; static uint32_t opal_heartbeat; static struct task_struct *kopald_tsk; +bool in_opal_text_heap_stack(u64 address) +{ + return (address >= opal.base && address < opal.base + opal.size); +} + void opal_configure_cores(void) { u64 reinit_flags = 0; diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c index 82e1a3ee6e0f..ade1adcc1ab8 100644 --- a/arch/powerpc/xmon/xmon.c +++ b/arch/powerpc/xmon/xmon.c @@ -452,6 +452,15 @@ static inline int unrecoverable_excp(struct pt_regs *regs) #endif } +static bool in_opal(unsigned long addr) +{ + if (firmware_has_feature(FW_FEATURE_OPAL)) + if (in_opal_text_heap_stack(addr)) + return true; + + return false; +} + static int xmon_core(struct pt_regs *regs, int fromipi) { int cmd = 0; @@ -510,6 +519,9 @@ static int xmon_core(struct pt_regs *regs, int fromipi) xmon_fault_jmp[cpu] = recurse_jmp; + if (in_opal(regs->nip)) + printf("xmon: cpu 0x%x stopped in OPAL!\n", cpu); + bp = NULL; if ((regs->msr & (MSR_IR|MSR_PR|MSR_64BIT)) == (MSR_IR|MSR_64BIT)) bp = at_breakpoint(regs->nip); @@ -1484,8 +1496,23 @@ static void xmon_show_stack(unsigned long sp, unsigned long lr, unsigned long marker; struct pt_regs regs; + if (in_opal(sp)) { + struct debug_struct { + unsigned long nip; + unsigned long r1; + unsigned long r1_caller; + } db; + printf("SP is in OPAL, calling OPAL to dump stack\n"); + db.nip = cpu_to_be64(pc); + db.r1 = cpu_to_be64(sp); + opal_debug(1, (unsigned long)&db); + sp = be64_to_cpu(db.r1_caller); + } + while (max_to_print--) { if (!is_kernel_addr(sp)) { + if (in_opal(pc) && in_opal(sp)) + printf("SP (%lx) is in OPAL\n", sp); if (sp != 0) printf("SP (%lx) is in userspace\n", sp); break; -- 2.16.1
