From: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
To: linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Sai Praneeth <sai.praneeth.prakhya@intel.com>,
"Lee, Chun-Yi" <jlee@suse.com>, Borislav Petkov <bp@alien8.de>,
Tony Luck <tony.luck@intel.com>,
Andy Lutomirski <luto@kernel.org>,
"Michael S. Tsirkin" <mst@redhat.com>,
Ricardo Neri <ricardo.neri@intel.com>,
Matt Fleming <matt@codeblueprint.co.uk>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Ravi Shankar <ravi.v.shankar@intel.com>
Subject: [PATCH 0/3] Use mm_struct and switch_mm() instead of manually
Date: Sat, 16 Dec 2017 16:05:58 -0800 [thread overview]
Message-ID: <1513469158-5638-1-git-send-email-sai.praneeth.prakhya@intel.com> (raw)
From: Sai Praneeth <sai.praneeth.prakhya@intel.com>
Presently, in x86, to invoke any efi function like
efi_set_virtual_address_map() or any efi_runtime_service() the code path
typically involves read_cr3() (save previous pgd), write_cr3()
(write efi_pgd) and calling efi function. Likewise after returning from
efi function the code path typically involves read_cr3() (save efi_pgd),
write_cr3() (write previous pgd). We do this couple of times in efi
subsystem of Linux kernel, instead we can use helper function
efi_switch_mm() to do this. This improves readability and maintainability.
Also, instead of maintaining a separate struct "efi_scratch" to store/restore
efi_pgd, we can use mm_struct to do this.
I have tested this patch set against LUV (Linux UEFI Validation), so I
think I didn't break any existing configurations. I have tested this
patch set for
1. x86_64,
2. x86_32,
3. Mixed mode
with efi=old_map and for kexec kernel. Please let me know if I have
missed any other configurations.
Changes in V2:
1. Resolve mm_dropping() issue by not mm_dropping()/mm_grabbing() any mm,
as we are not losing/creating any references.
Changes in V3:
1. When CPUMASK_OFFSTACK is enabled, switch_mm_irqs_off() sets cpumask
by calling cpumask_set_cpu(). This panics kernel as efi_mm is not
initialized, therefore initialize efi_mm in efi_alloc_page_tables().
Note:
This patch set is based on Linus's tree v4.15-rc3
Sai Praneeth (3):
efi: Use efi_mm in x86 as well as ARM
x86/efi: Replace efi_pgd with efi_mm.pgd
x86/efi: Use efi_switch_mm() rather than manually twiddling with %cr3
arch/x86/include/asm/efi.h | 29 +++++++++---------
arch/x86/platform/efi/efi_64.c | 59 +++++++++++++++++++-----------------
arch/x86/platform/efi/efi_thunk_64.S | 2 +-
drivers/firmware/efi/arm-runtime.c | 9 ------
drivers/firmware/efi/efi.c | 9 ++++++
include/linux/efi.h | 2 ++
6 files changed, 57 insertions(+), 53 deletions(-)
Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Lee, Chun-Yi <jlee@suse.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Ricardo Neri <ricardo.neri@intel.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Tested-by: Bhupesh Sharma <bhsharma@redhat.com>
--
2.1.4
next reply other threads:[~2017-12-17 0:11 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-17 0:05 Sai Praneeth Prakhya [this message]
2017-12-17 21:09 ` [PATCH 0/3] Use mm_struct and switch_mm() instead of manually Bhupesh Sharma
2017-12-19 6:23 ` Prakhya, Sai Praneeth
-- strict thread matches above, loose matches on Subject: below --
2017-08-15 19:18 Sai Praneeth Prakhya
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