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Date: Mon, 31 Jul 2017 21:30:07 +0800
From: "bhe@...hat.com" <bhe@...hat.com>
To: "tglx@...utronix.de" <tglx@...utronix.de>,
"Rafael J. Wysocki" <rjw@...ysocki.net>,
Dou Liyang <douly.fnst@...fujitsu.com>
Cc: joeyli.kernel@...il.com, "Zheng, Lv" <lv.zheng@...el.com>,
"x86@...nel.org" <x86@...nel.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"mingo@...nel.org" <mingo@...nel.org>,
"hpa@...or.com" <hpa@...or.com>,
"ebiederm@...ssion.com" <ebiederm@...ssion.com>,
"peterz@...radead.org" <peterz@...radead.org>,
"izumi.taku@...fujitsu.com" <izumi.taku@...fujitsu.com>,
"tokunaga.keiich@...fujitsu.com" <tokunaga.keiich@...fujitsu.com>,
"linux-acpi@...r.kernel.org" <linux-acpi@...r.kernel.org>,
Julian Wollrath <jwollrath@....de>
Subject: Re: [PATCH v7 12/13] ACPI / init: Invoke early ACPI initialization
earlier
On 07/31/17 at 07:20pm, Dou Liyang wrote:
> Hi Baoquan,
>
> At 07/27/2017 02:08 PM, bhe@...hat.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.fnst@...fujitsu.com]
> > > > > > > Sent: Friday, July 14, 2017 1:53 PM
> > > > > > > To: x86@...nel.org; linux-kernel@...r.kernel.org
> > > > > > > Cc: tglx@...utronix.de; mingo@...nel.org; hpa@...or.com; ebiederm@...ssion.com; bhe@...hat.com;
> > > > > > > peterz@...radead.org; izumi.taku@...fujitsu.com; tokunaga.keiich@...fujitsu.com; Dou Liyang
> > > > > > > <douly.fnst@...fujitsu.com>; linux-acpi@...r.kernel.org; Rafael J. Wysocki <rjw@...ysocki.net>; Zheng,
> > > > > > > Lv <lv.zheng@...el.com>; Julian Wollrath <jwollrath@....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.ye@...el.com>
> > > > > > > Signed-off-by: Dou Liyang <douly.fnst@...fujitsu.com>
> > > > > > > Cc: linux-acpi@...r.kernel.org
> > > > > > > Cc: Rafael J. Wysocki <rjw@...ysocki.net>
> > > > > > > Cc: Zheng, Lv <lv.zheng@...el.com>
> > > > > > > Cc: Julian Wollrath <jwollrath@....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
> > > > > > >
> > > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > >
> > > > >
> > > >
> > > >
> > > >
> > >
> > >
> >
> >
> >
>
>
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