Hi, Zheng
At 07/28/2017 09:53 AM, Zheng, Lv wrote:
[...]
Dmar hardware support interrupt remapping and io remapping separately. But
intel_iommu_init() is called later than intel_prepare_irq_remapping().
So what if make dmar_table_init() a reentrant function? You can just
have a try, but maybe not a good idea, the dmar table will be parsed
twice.
Yes, It is precisely one reason that I gave up invoking
acpi_put_table().
Parsing a table twice is not a problem on x86.
If you check the code, there are many examples.
It's actually required if you want to use a table both in early stage and late stage.
I am sorry I don't explain clearly.
Yeah, in current kernel, The DMAR table has been parsed twice as well.
one is in detect_intel_iommu(), the other is in dmar_table_init().
Here we focus on the reentrant dmar_table_init(), this func contains
many callback for parsing different DMAR type structures, such as DRHD,
RMRR.
acpi_put_table() can release the mapped DMAR address, but we should
clear the remapping structure types manually. and I think parsing these
DMAR type structures again may have an influence on interrupt remapping.
Thanks,
dou.
Thanks
Thanks,
dou.
Thanks,
dou.
Thanks
Lv
From: Dou Liyang [mailto:douly.fnst@xxxxxxxxxxxxxx]
Sent: Friday, July 14, 2017 1:53 PM
To: x86@xxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
Cc: tglx@xxxxxxxxxxxxx; mingo@xxxxxxxxxx; hpa@xxxxxxxxx; ebiederm@xxxxxxxxxxxx; bhe@xxxxxxxxxx;
peterz@xxxxxxxxxxxxx; izumi.taku@xxxxxxxxxxxxxx; tokunaga.keiich@xxxxxxxxxxxxxx; Dou Liyang
<douly.fnst@xxxxxxxxxxxxxx>; linux-acpi@xxxxxxxxxxxxxxx; Rafael J. Wysocki <rjw@xxxxxxxxxxxxx>;
Zheng,
Lv <lv.zheng@xxxxxxxxx>; Julian Wollrath <jwollrath@xxxxxx>
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@xxxxxxxxx>
Signed-off-by: Dou Liyang <douly.fnst@xxxxxxxxxxxxxx>
Cc: linux-acpi@xxxxxxxxxxxxxxx
Cc: Rafael J. Wysocki <rjw@xxxxxxxxxxxxx>
Cc: Zheng, Lv <lv.zheng@xxxxxxxxx>
Cc: Julian Wollrath <jwollrath@xxxxxx>
---
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
--
To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
