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| author | Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> | 2019-03-05 01:12:19 +0530 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2019-05-03 02:54:57 +1000 |
| commit | de269129a48a2d590ba1d20c719e19d86e3ddb3f (patch) | |
| tree | f24b4a3afde2d90ce614a347129acf6324315a1a /arch/powerpc/platforms/powernv/opal.c | |
| parent | 0acb5f64560a052fd66ab37b212a72964847160f (diff) | |
| download | linux-stable-de269129a48a2d590ba1d20c719e19d86e3ddb3f.tar.gz linux-stable-de269129a48a2d590ba1d20c719e19d86e3ddb3f.tar.bz2 linux-stable-de269129a48a2d590ba1d20c719e19d86e3ddb3f.zip | |
powerpc/hmi: Fix kernel hang when TB is in error state.
On TOD/TB errors timebase register stops/freezes until HMI error recovery
gets TOD/TB back into running state. On successful recovery, TB starts
running again and udelay() that relies on TB value continues to function
properly. But in case when HMI fails to recover from TOD/TB errors, the
TB register stay freezed. With TB not running the __delay() function
keeps looping and never return. If __delay() is called while in panic
path then system hangs and never reboots after panic.
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/platforms/powernv/opal.c')
| -rw-r--r-- | arch/powerpc/platforms/powernv/opal.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c index 737c51d63480..f2b063b027f0 100644 --- a/arch/powerpc/platforms/powernv/opal.c +++ b/arch/powerpc/platforms/powernv/opal.c @@ -614,6 +614,27 @@ int opal_hmi_exception_early(struct pt_regs *regs) return 0; } +int opal_hmi_exception_early2(struct pt_regs *regs) +{ + s64 rc; + __be64 out_flags; + + /* + * call opal hmi handler. + * Check 64-bit flag mask to find out if an event was generated, + * and whether TB is still valid or not etc. + */ + rc = opal_handle_hmi2(&out_flags); + if (rc != OPAL_SUCCESS) + return 0; + + if (be64_to_cpu(out_flags) & OPAL_HMI_FLAGS_NEW_EVENT) + local_paca->hmi_event_available = 1; + if (be64_to_cpu(out_flags) & OPAL_HMI_FLAGS_TOD_TB_FAIL) + tb_invalid = true; + return 1; +} + /* HMI exception handler called in virtual mode during check_irq_replay. */ int opal_handle_hmi_exception(struct pt_regs *regs) { |