Hi Will,

On 30 March 2016 at 00:35, Will Deacon [off-list ref] wrote:

On Tue, Mar 29, 2016 at 03:44:18PM +0800, fu.wei at linaro.org wrote:

quoted

From: Tomasz Nowicki <redacted>

This commit provides APEI arch-specific bits for aarch64

Meanwhile,
(1)add a new subfunction "hest_ia32_init" for
"acpi_disable_cmcff" which is used by IA-32 Architecture
Corrected Machine Check (CMC).
(2)move HEST type (ACPI_HEST_TYPE_IA32_CORRECTED_CHECK) checking to
a generic place.
(3)select EFI when ACPI_APEI is set on ARM64,
because arch_apei_get_mem_attribute is using efi_mem_attributes on ARM64.

[Fu Wei: improve && upstream]

Signed-off-by: Tomasz Nowicki <redacted>
Tested-by: Jonathan (Zhixiong) Zhang <redacted>
Signed-off-by: Fu Wei <redacted>
Acked-by: Hanjun Guo <redacted>
Tested-by: Tyler Baicar <redacted>
---
Changelog:
v8: Fix a "undefined reference" bug by selecting EFI when ACPI_APEI is set
    on ARM64.

v7: https://lkml.org/lkml/2016/3/17/183
    Add comment for arch_apei_flush_tlb_one in arch/arm64/include/asm/acpi.h

v6: https://lists.linaro.org/pipermail/linaro-acpi/2016-March/006644.html
    Move HEST type (ACPI_HEST_TYPE_IA32_CORRECTED_CHECK) checking to
    a generic place.
    Delete HAVE_ACPI_APEI_HEST_IA32.

v5: https://lkml.org/lkml/2015/12/10/131
    Add "HAVE_ACPI_APEI_HEST_IA32" instead of
    "#if defined(__i386__) || defined(__x86_64__)".

v4: https://lkml.org/lkml/2015/12/8/188
    Rebase to latest kernel version(4.4-rc4).
    Move arch_apei_flush_tlb_one into header file as a inline function
    Add a new subfunction "hest_ia_init" for "acpi_disable_cmcff".

v3: https://lkml.org/lkml/2015/12/3/521
    Remove "acpi_disable_cmcff" from arm64 code,
    and wrap it in hest.c by "#if defined(__i386__) || defined(__x86_64__)"

v2: https://lkml.org/lkml/2015/12/2/432
    Rebase to latest kernel version(4.4-rc3).
    Move arch_apei_flush_tlb_one() to arch/arm64/kernel/acpi.c

v1: https://lkml.org/lkml/2015/8/14/199
    Move arch_apei_flush_tlb_one() to arch/arm64/include/asm/apci.h.
    Delete arch/arm64/kernel/apei.c.
    Add "#ifdef CONFIG_ACPI_APEI" for "acpi_disable_cmcff".

 arch/arm64/Kconfig            |  1 +
 arch/arm64/include/asm/acpi.h | 15 ++++++++++++++-
 arch/x86/kernel/acpi/apei.c   |  3 ---
 drivers/acpi/apei/Kconfig     |  1 +
 drivers/acpi/apei/hest.c      | 18 +++++++++++++++---
 5 files changed, 31 insertions(+), 7 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 4f43622..08952ec 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig

@@ -3,6 +3,7 @@ config ARM64
      select ACPI_CCA_REQUIRED if ACPI
      select ACPI_GENERIC_GSI if ACPI
      select ACPI_REDUCED_HARDWARE_ONLY if ACPI
+     select HAVE_ACPI_APEI if ACPI
      select ARCH_HAS_DEVMEM_IS_ALLOWED
      select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
      select ARCH_HAS_ELF_RANDOMIZE

diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
index aee323b..4a6c959 100644
--- a/arch/arm64/include/asm/acpi.h
+++ b/arch/arm64/include/asm/acpi.h

@@ -17,6 +17,7 @@

 #include <asm/cputype.h>
 #include <asm/smp_plat.h>
+#include <asm/tlbflush.h>

 /* Macros for consistency checks of the GICC subtable of MADT */
 #define ACPI_MADT_GICC_LENGTH        \

@@ -110,7 +111,19 @@ static inline const char *acpi_get_enable_method(int cpu)
 }

 #ifdef       CONFIG_ACPI_APEI
+#define acpi_disable_cmcff 1
 pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr);
-#endif

+/*
+ * This inline function is used in IRQ context (by GHES driver now),
+ * see ghes_iounmap_irq and ghes_iounmap_nmi in drivers/acpi/apei/ghes.c.
+ * The page mapped is reserved for firmware in kernel. This invalidate TLB
+ * maintenance should be broadcasted safely to make sure that all the cores
+ * will do TLB invalidation, then get the right pages.
+ */

How about:

 /*
  * Despite its name, this function must still broadcast the TLB
  * invalidation in order to ensure other CPUs don't up with with junk
  * entries as a result of speculation. Unusually, its also called in
  * IRQ context (ghes_iounmap_irq) so if we ever need to use IPIs for
  * TLB broadcasting, then we're in trouble here.
  */

Good, thanks for your help

With that,

Acked-by: Will Deacon <redacted>

Thanks ! :-)

Will

-- 
Best regards,

Fu Wei
Software Engineer
Red Hat Software (Beijing) Co.,Ltd.Shanghai Branch
Ph: +86 21 61221326(direct)
Ph: +86 186 2020 4684 (mobile)
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