On 07/31/17 at 07:20pm, Dou Liyang wrote: > Hi Baoquan, > > At 07/27/2017 02:08 PM, b...@redhat.com wrote: > > On 07/26/17 at 08:19pm, Dou Liyang wrote: > > > Hi Baoquan, > [...] > > > > > > I am looking for Thinkpad x121e (AMD E-450 APU) to test. I have tested > > > it in Thinkpad s430, It's OK. > > > > > > BTY, I am confused how does the ACPI subsystem affect PIT which > > > will be used to fast calibrate CPU frequency[2]. > > In combination with what Joey said[1] and the code, I guess, > > The acpi_enable() called in acpi_enable_system() transfers the system > into ACPI mode and write data to an I/O port. PIT works using the I/O > port. In Thinkpad x121e with ACPI mode, the counter in PIT couldn't > count right and might got an error value. > > [1] https://lkml.org/lkml/2014/3/12/3
Awesome! I guess you are possibly correct. A MUST job for entering into ACPI mode is to enable SCI and hook a handler. SCI will take over all acpi interrupt events. I googled SCI and vaguely remember someone said the I/O port r/w event also will be handled by SCI, but didn't find a clear description in ACPI spec. If that cause failure, it might happen inside pit_expect_msb() called by quick_pit_calibrate(), maybe you can try to add debug message in this place, not very sure if it be debugged. Maybe tglx or Rafael can help have a look and confirm if it's correct or not. Thanks Baoquan > > > > I checked code, and have no any idea. Add Joey Lee to list, see if he > > can help answer this. > > > > > > > > Do you have any idea? > > > > > > [1] https://lkml.org/lkml/2014/3/10/123 > > > [2] https://lkml.org/lkml/2014/3/12/3 > > > > > > > > > drivers/iommu/dmar.c | 27 +++++++++++---------------- > > > drivers/iommu/intel-iommu.c | 2 ++ > > > drivers/iommu/intel_irq_remapping.c | 17 ++++++++++++++++- > > > include/linux/dmar.h | 2 ++ > > > init/main.c | 2 +- > > > 5 files changed, 32 insertions(+), 18 deletions(-) > > > > > > diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c > > > index c8b0329..e6261b7 100644 > > > --- a/drivers/iommu/dmar.c > > > +++ b/drivers/iommu/dmar.c > > > @@ -68,6 +68,8 @@ DECLARE_RWSEM(dmar_global_lock); > > > LIST_HEAD(dmar_drhd_units); > > > > > > struct acpi_table_header * __initdata dmar_tbl; > > > +struct acpi_table_header * __initdata dmar_tbl_original; > > > + > > > static int dmar_dev_scope_status = 1; > > > static unsigned long dmar_seq_ids[BITS_TO_LONGS(DMAR_UNITS_SUPPORTED)]; > > > > > > @@ -627,6 +629,7 @@ parse_dmar_table(void) > > > * fixed map. > > > */ > > > dmar_table_detect(); > > > + dmar_tbl_original = dmar_tbl; > > > > > > /* > > > * ACPI tables may not be DMA protected by tboot, so use DMAR copy > > > @@ -811,26 +814,18 @@ int __init dmar_dev_scope_init(void) > > > > > > int __init dmar_table_init(void) > > > { > > > - static int dmar_table_initialized; > > > int ret; > > > > > > - if (dmar_table_initialized == 0) { > > > - ret = parse_dmar_table(); > > > - if (ret < 0) { > > > - if (ret != -ENODEV) > > > - pr_info("Parse DMAR table failure.\n"); > > > - } else if (list_empty(&dmar_drhd_units)) { > > > - pr_info("No DMAR devices found\n"); > > > - ret = -ENODEV; > > > - } > > > - > > > - if (ret < 0) > > > - dmar_table_initialized = ret; > > > - else > > > - dmar_table_initialized = 1; > > > + ret = parse_dmar_table(); > > > + if (ret < 0) { > > > + if (ret != -ENODEV) > > > + pr_info("Parse DMAR table failure.\n"); > > > + } else if (list_empty(&dmar_drhd_units)) { > > > + pr_info("No DMAR devices found\n"); > > > + ret = -ENODEV; > > > } > > > > > > - return dmar_table_initialized < 0 ? dmar_table_initialized : 0; > > > + return ret; > > > } > > > > > > static void warn_invalid_dmar(u64 addr, const char *message) > > > diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c > > > index 687f18f..90f74f4 100644 > > > --- a/drivers/iommu/intel-iommu.c > > > +++ b/drivers/iommu/intel-iommu.c > > > @@ -4832,6 +4832,8 @@ int __init intel_iommu_init(void) > > > } > > > > > > down_write(&dmar_global_lock); > > > + > > > + intel_iommu_free_dmars(); > > > if (dmar_table_init()) { > > > if (force_on) > > > panic("tboot: Failed to initialize DMAR table\n"); > > > diff --git a/drivers/iommu/intel_irq_remapping.c > > > b/drivers/iommu/intel_irq_remapping.c > > > index a5b89f6..ccaacda 100644 > > > --- a/drivers/iommu/intel_irq_remapping.c > > > +++ b/drivers/iommu/intel_irq_remapping.c > > > @@ -675,7 +675,7 @@ static void __init intel_cleanup_irq_remapping(void) > > > pr_warn("Failed to enable irq remapping. You are vulnerable to > > > irq-injection attacks.\n"); > > > } > > > > > > -static int __init intel_prepare_irq_remapping(void) > > > +static int __init __intel_prepare_irq_remapping(void) > > > { > > > struct dmar_drhd_unit *drhd; > > > struct intel_iommu *iommu; > > > @@ -743,6 +743,21 @@ static int __init intel_prepare_irq_remapping(void) > > > return -ENODEV; > > > } > > > > > > +static int __init intel_prepare_irq_remapping(void) > > > +{ > > > + int ret; > > > + > > > + ret = __intel_prepare_irq_remapping(); > > > + > > > + if (dmar_tbl_original) { > > > + acpi_put_table(dmar_tbl_original); > > > + dmar_tbl_original = NULL; > > > + dmar_tbl = NULL; > > > + } > > > + > > > + return ret; > > > +} > > > + > > > /* > > > * Set Posted-Interrupts capability. > > > */ > > > diff --git a/include/linux/dmar.h b/include/linux/dmar.h > > > index e8ffba1..987b076 100644 > > > --- a/include/linux/dmar.h > > > +++ b/include/linux/dmar.h > > > @@ -50,6 +50,8 @@ struct dmar_dev_scope { > > > > > > #ifdef CONFIG_DMAR_TABLE > > > extern struct acpi_table_header *dmar_tbl; > > > +extern struct acpi_table_header *dmar_tbl_original; > > > + > > > struct dmar_drhd_unit { > > > struct list_head list; /* list of drhd units */ > > > struct acpi_dmar_header *hdr; /* ACPI header */ > > > diff --git a/init/main.c b/init/main.c > > > index 52dee20..052481f 100644 > > > --- a/init/main.c > > > +++ b/init/main.c > > > @@ -655,12 +655,12 @@ asmlinkage __visible void __init start_kernel(void) > > > kmemleak_init(); > > > setup_per_cpu_pageset(); > > > numa_policy_init(); > > > - acpi_early_init(); > > > if (late_time_init) > > > late_time_init(); > > > calibrate_delay(); > > > pidmap_init(); > > > anon_vma_init(); > > > + acpi_early_init(); > > > #ifdef CONFIG_X86 > > > if (efi_enabled(EFI_RUNTIME_SERVICES)) > > > efi_enter_virtual_mode(); > > > > > > Thanks, > > > dou. > > > > > > > > > > > > > > > > > > > Thanks, > > > > > > > > > > dou. > > > > > > > > > > > > Thanks > > > > > > Lv > > > > > > > > > > > > > From: Dou Liyang [mailto:douly.f...@cn.fujitsu.com] > > > > > > > Sent: Friday, July 14, 2017 1:53 PM > > > > > > > To: x...@kernel.org; linux-kernel@vger.kernel.org > > > > > > > Cc: t...@linutronix.de; mi...@kernel.org; h...@zytor.com; > > > > > > > ebied...@xmission.com; b...@redhat.com; > > > > > > > pet...@infradead.org; izumi.t...@jp.fujitsu.com; > > > > > > > tokunaga.kei...@jp.fujitsu.com; Dou Liyang > > > > > > > <douly.f...@cn.fujitsu.com>; linux-a...@vger.kernel.org; Rafael > > > > > > > J. Wysocki <r...@rjwysocki.net>; Zheng, > > > > > > > Lv <lv.zh...@intel.com>; Julian Wollrath <jwollr...@web.de> > > > > > > > Subject: [PATCH v7 12/13] ACPI / init: Invoke early ACPI > > > > > > > initialization earlier > > > > > > > > > > > > > > Linux uses acpi_early_init() to put the ACPI table management into > > > > > > > the late stage from the early stage where the mapped ACPI tables > > > > > > > is > > > > > > > temporary and should be unmapped. > > > > > > > > > > > > > > But, now initializing interrupt delivery mode should map and > > > > > > > parse the > > > > > > > DMAR table earlier in the early stage. This causes an ACPI error > > > > > > > when > > > > > > > Linux reallocates the ACPI root tables. Because Linux doesn't > > > > > > > unmapped > > > > > > > the DMAR table after using in the early stage. > > > > > > > > > > > > > > Invoke acpi_early_init() earlier before late_time_init(), Keep > > > > > > > the DMAR > > > > > > > be mapped and parsed in late stage like before. > > > > > > > > > > > > > > Reported-by: Xiaolong Ye <xiaolong...@intel.com> > > > > > > > Signed-off-by: Dou Liyang <douly.f...@cn.fujitsu.com> > > > > > > > Cc: linux-a...@vger.kernel.org > > > > > > > Cc: Rafael J. Wysocki <r...@rjwysocki.net> > > > > > > > Cc: Zheng, Lv <lv.zh...@intel.com> > > > > > > > Cc: Julian Wollrath <jwollr...@web.de> > > > > > > > --- > > > > > > > Test in my own PC(Lenovo M4340). > > > > > > > Ask help for doing regression testing for the bug said in commit > > > > > > > c4e1acbb35e4 > > > > > > > ("ACPI / init: Invoke early ACPI initialization later"). > > > > > > > > > > > > > > init/main.c | 2 +- > > > > > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > > > > > > > > > diff --git a/init/main.c b/init/main.c > > > > > > > index df58a41..7a09467 100644 > > > > > > > --- a/init/main.c > > > > > > > +++ b/init/main.c > > > > > > > @@ -654,12 +654,12 @@ asmlinkage __visible void __init > > > > > > > start_kernel(void) > > > > > > > kmemleak_init(); > > > > > > > setup_per_cpu_pageset(); > > > > > > > numa_policy_init(); > > > > > > > + acpi_early_init(); > > > > > > > if (late_time_init) > > > > > > > late_time_init(); > > > > > > > calibrate_delay(); > > > > > > > pidmap_init(); > > > > > > > anon_vma_init(); > > > > > > > - acpi_early_init(); > > > > > > > #ifdef CONFIG_X86 > > > > > > > if (efi_enabled(EFI_RUNTIME_SERVICES)) > > > > > > > efi_enter_virtual_mode(); > > > > > > > -- > > > > > > > 2.5.5 > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >
