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author | Vaibhav Jain <vaibhav@linux.ibm.com> | 2018-08-27 15:43:54 +0530 |
---|---|---|
committer | Stewart Smith <stewart@linux.ibm.com> | 2018-10-16 18:26:24 +1100 |
commit | 7cef472ed1fea75cc63cb0d8ac86d6a13d08517d (patch) | |
tree | f84de5d2efda59f1f5859536324a4eb3f61f6236 | |
parent | c8e1d61ae2c94d3ac5d4598800f793b313726b2a (diff) | |
download | skiboot-7cef472ed1fea75cc63cb0d8ac86d6a13d08517d.zip skiboot-7cef472ed1fea75cc63cb0d8ac86d6a13d08517d.tar.gz skiboot-7cef472ed1fea75cc63cb0d8ac86d6a13d08517d.tar.bz2 |
opal/hmi: Wakeup the cpu before reading core_fir
When stop state 5 is enabled, reading the core_fir during an HMI can
result in a xscom read error with xscom_read() returning an
OPAL_XSCOM_PARTIAL_GOOD error code and core_fir value of all FFs. At
present this return error code is not handled in decode_core_fir()
hence the invalid core_fir value is sent to the kernel where it
interprets it as a FATAL hmi causing a system check-stop.
This can be prevented by forcing the core to wake-up using before
reading the core_fir. Hence this patch wraps the call to
read_core_fir() within calls to dctl_set_special_wakeup() and
dctl_clear_special_wakeup().
Suggested-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Signed-off-by: Mahesh J Salgaonkar <mahesh@linux.vnet.ibm.com>
Acked-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Reviewed-by: Shilpasri G Bhat <shilpa.bhat@linux.vnet.ibm.com>
Signed-off-by: Stewart Smith <stewart@linux.ibm.com>
-rw-r--r-- | core/hmi.c | 21 |
1 files changed, 15 insertions, 6 deletions
@@ -379,7 +379,7 @@ static bool decode_core_fir(struct cpu_thread *cpu, { uint64_t core_fir; uint32_t core_id; - int i; + int i, swkup_rc; bool found = false; int64_t ret; const char *loc; @@ -390,14 +390,19 @@ static bool decode_core_fir(struct cpu_thread *cpu, core_id = pir_to_core_id(cpu->pir); + /* Force the core to wakeup, otherwise reading core_fir is unrealiable + * if stop-state 5 is enabled. + */ + swkup_rc = dctl_set_special_wakeup(cpu); + /* Get CORE FIR register value. */ ret = read_core_fir(cpu->chip_id, core_id, &core_fir); - if (ret == OPAL_HARDWARE) { - prerror("XSCOM error reading CORE FIR\n"); - /* If the FIR can't be read, we should checkstop. */ - return true; - } else if (ret == OPAL_WRONG_STATE) { + if (!swkup_rc) + dctl_clear_special_wakeup(cpu); + + + if (ret == OPAL_WRONG_STATE) { /* * CPU is asleep, so it probably didn't cause the checkstop. * If no other HMI cause is found a "catchall" checkstop @@ -408,6 +413,10 @@ static bool decode_core_fir(struct cpu_thread *cpu, "FIR read failed, chip %d core %d asleep\n", cpu->chip_id, core_id); return false; + } else if (ret != OPAL_SUCCESS) { + prerror("XSCOM error reading CORE FIR\n"); + /* If the FIR can't be read, we should checkstop. */ + return true; } if (!core_fir) |