From: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
To: linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org,
matt@codeblueprint.co.uk, ard.biesheuvel@linaro.org
Cc: jlee@suse.com, bp@alien8.de, tony.luck@intel.com,
luto@kernel.org, mst@redhat.com, ricardo.neri@intel.com,
ravi.v.shankar@intel.com,
Sai Praneeth <sai.praneeth.prakhya@intel.com>
Subject: [PATCH V2 0/3] Use mm_struct and switch_mm() instead of manually
Date: Mon, 28 Aug 2017 16:37:09 -0700 [thread overview]
Message-ID: <1503963432-32055-1-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.
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 | 52 ++++++++++++++++++++----------------
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, 55 insertions(+), 48 deletions(-)
--
2.1.4
next reply other threads:[~2017-08-28 23:42 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-28 23:37 Sai Praneeth Prakhya [this message]
2017-08-28 23:37 ` [PATCH V2 1/3] efi: Use efi_mm in x86 as well as ARM Sai Praneeth Prakhya
2017-08-28 23:37 ` [PATCH V2 2/3] x86/efi: Replace efi_pgd with efi_mm.pgd Sai Praneeth Prakhya
2017-08-28 23:37 ` [PATCH V2 3/3] x86/efi: Use efi_switch_mm() rather than manually twiddling with %cr3 Sai Praneeth Prakhya
2017-09-02 14:08 ` [PATCH V2 0/3] Use mm_struct and switch_mm() instead of manually Bhupesh Sharma
2017-09-02 14:23 ` Bhupesh Sharma
2017-09-03 7:46 ` Prakhya, Sai Praneeth
2017-09-05 7:43 ` Bhupesh Sharma
2017-09-06 2:21 ` Sai Praneeth Prakhya
2017-09-06 2:43 ` Sai Praneeth Prakhya
2017-09-06 9:00 ` Prakhya, Sai Praneeth
2017-09-08 11:55 ` Bhupesh Sharma
2017-09-11 7:10 ` Prakhya, Sai Praneeth
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