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| author | Will Deacon <will.deacon@arm.com> | 2015-10-06 20:46:24 +0300 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2015-10-07 13:55:41 +0300 |
| commit | 5aec715d7d3122f77cabaa7578d9d25a0c1ed20e (patch) | |
| tree | 8d75ae3f1f72bfa8ee77fdea406b6c9dcfaf4e60 /arch/arm64/include/asm/thread_info.h | |
| parent | 8e63d38876691756f9bc6930850f1fb77809be1b (diff) | |
| download | linux-5aec715d7d3122f77cabaa7578d9d25a0c1ed20e.tar.xz | |
arm64: mm: rewrite ASID allocator and MM context-switching code
Our current switch_mm implementation suffers from a number of problems:
(1) The ASID allocator relies on IPIs to synchronise the CPUs on a
rollover event
(2) Because of (1), we cannot allocate ASIDs with interrupts disabled
and therefore make use of a TIF_SWITCH_MM flag to postpone the
actual switch to finish_arch_post_lock_switch
(3) We run context switch with a reserved (invalid) TTBR0 value, even
though the ASID and pgd are updated atomically
(4) We take a global spinlock (cpu_asid_lock) during context-switch
(5) We use h/w broadcast TLB operations when they are not required
(e.g. in flush_context)
This patch addresses these problems by rewriting the ASID algorithm to
match the bitmap-based arch/arm/ implementation more closely. This in
turn allows us to remove much of the complications surrounding switch_mm,
including the ugly thread flag.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/include/asm/thread_info.h')
| -rw-r--r-- | arch/arm64/include/asm/thread_info.h | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h index dcd06d18a42a..555c6dec5ef2 100644 --- a/arch/arm64/include/asm/thread_info.h +++ b/arch/arm64/include/asm/thread_info.h @@ -111,7 +111,6 @@ static inline struct thread_info *current_thread_info(void) #define TIF_RESTORE_SIGMASK 20 #define TIF_SINGLESTEP 21 #define TIF_32BIT 22 /* 32bit process */ -#define TIF_SWITCH_MM 23 /* deferred switch_mm */ #define _TIF_SIGPENDING (1 << TIF_SIGPENDING) #define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED) |