From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Zhang, Jonathan Zhixiong" Subject: Re: [PATCH 1/2] arm64: apei: implement arch_apei_get_mem_attributes() Date: Fri, 14 Aug 2015 11:55:27 -0700 Message-ID: <55CE399F.1030108@codeaurora.org> References: <1439396234-22863-1-git-send-email-matt@codeblueprint.co.uk> <1439396234-22863-2-git-send-email-matt@codeblueprint.co.uk> <20150813082207.GB14610@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20150813082207.GB14610-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> Sender: linux-efi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Ingo Molnar , Matt Fleming Cc: Thomas Gleixner , "H. Peter Anvin" , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Matt Fleming , Ard Biesheuvel , Catalin Marinas , Hanjun Guo List-Id: linux-efi@vger.kernel.org On 8/13/2015 1:22 AM, Ingo Molnar wrote: > > * Matt Fleming wrote: > >> From: "Jonathan (Zhixiong) Zhang" >> >> Table 8 of UEFI 2.5 section 2.3.6.1 defines mappings from EFI >> memory types to MAIR attribute encodings for arm64. >> >> If the physical address has memory attributes defined by EFI >> memmap as EFI_MEMORY_[UC|WC|WT], return approprate page protection >> type according to the UEFI spec. Otherwise, return PAGE_KERNEL. >> >> Reviewed-by: Catalin Marinas >> Acked-by: Hanjun Guo >> Reviewed-by: Ard Biesheuvel >> Signed-off-by: Jonathan (Zhixiong) Zhang >> Signed-off-by: Matt Fleming >> --- >> arch/arm64/include/asm/acpi.h | 30 ++++++++++++++++++++++++++++++ >> 1 file changed, 30 insertions(+) >> >> diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h >> index 406485ed110a..1cbad43e561d 100644 >> --- a/arch/arm64/include/asm/acpi.h >> +++ b/arch/arm64/include/asm/acpi.h >> @@ -19,6 +19,11 @@ >> #include >> #include >> >> +#ifdef CONFIG_ACPI_APEI >> +#include >> +#include >> +#endif >> + >> /* Macros for consistency checks of the GICC subtable of MADT */ >> #define ACPI_MADT_GICC_LENGTH \ >> (acpi_gbl_FADT.header.revision < 6 ? 76 : 80) >> @@ -92,4 +97,29 @@ static inline const char *acpi_get_enable_method(int cpu) >> { >> return acpi_psci_present() ? "psci" : NULL; >> } >> + >> +#ifdef CONFIG_ACPI_APEI >> +static inline pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr) >> +{ >> + /* >> + * According to "Table 8 Map: EFI memory types to AArch64 memory types" >> + * of UEFI 2.5 section 2.3.6.1, each EFI memory type is mapped to >> + * corresponding MAIR attribute encoding. > > s/mapped to corresponding/ > mapped to a corresponding Will do. > >> + * The EFI memory attribute advises all possible capabilities of a >> + * memory region. We use the most efficient capability. >> + */ >> + >> + u64 attr; >> + >> + attr = efi_mem_attributes(addr); >> + if (attr & EFI_MEMORY_WB) >> + return PAGE_KERNEL; >> + if (attr & EFI_MEMORY_WT) >> + return __pgprot(PROT_NORMAL_WT); >> + if (attr & EFI_MEMORY_WC) >> + return __pgprot(PROT_NORMAL_NC); >> + return __pgprot(PROT_DEVICE_nGnRnE); >> +} >> +#endif > > Also, this doesn't look like a small function - why is it inlined? The function grew a bit after its first version. Since it is on the fence of not being a small function, I did not change it to out of the line. I will move it to arch/arm64/kernel/acpi.c guarded by CONFIG_ACPI_APEI instead of having to create a very small new file, if there is no opposition. > > Moving it to .c would also slightly improve compilation times for every .c file > that includes asm/acpi.h. > > Thanks, > > Ingo > -- Jonathan (Zhixiong) Zhang The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project