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| author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2014-04-03 15:55:01 +0400 |
|---|---|---|
| committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2014-04-03 16:31:00 +0400 |
| commit | 1b948d6caec4f28e3524244ca0f77c6ae8ddceef (patch) | |
| tree | bc7e1d5800f10c39979d3f47872ba7047568f8a4 /arch/s390/include/asm/setup.h | |
| parent | 02a8f3abb708919149cb657a5202f4603f0c38e2 (diff) | |
| download | linux-1b948d6caec4f28e3524244ca0f77c6ae8ddceef.tar.xz | |
s390/mm,tlb: optimize TLB flushing for zEC12
The zEC12 machines introduced the local-clearing control for the IDTE
and IPTE instruction. If the control is set only the TLB of the local
CPU is cleared of entries, either all entries of a single address space
for IDTE, or the entry for a single page-table entry for IPTE.
Without the local-clearing control the TLB flush is broadcasted to all
CPUs in the configuration, which is expensive.
The reset of the bit mask of the CPUs that need flushing after a
non-local IDTE is tricky. As TLB entries for an address space remain
in the TLB even if the address space is detached a new bit field is
required to keep track of attached CPUs vs. CPUs in the need of a
flush. After a non-local flush with IDTE the bit-field of attached CPUs
is copied to the bit-field of CPUs in need of a flush. The ordering
of operations on cpu_attach_mask, attach_count and mm_cpumask(mm) is
such that an underindication in mm_cpumask(mm) is prevented but an
overindication in mm_cpumask(mm) is possible.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/include/asm/setup.h')
| -rw-r--r-- | arch/s390/include/asm/setup.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/s390/include/asm/setup.h b/arch/s390/include/asm/setup.h index 406f3a1e63ef..b31b22dba948 100644 --- a/arch/s390/include/asm/setup.h +++ b/arch/s390/include/asm/setup.h @@ -68,6 +68,7 @@ void create_mem_hole(struct mem_chunk mem_chunk[], unsigned long addr, #define MACHINE_FLAG_TOPOLOGY (1UL << 14) #define MACHINE_FLAG_TE (1UL << 15) #define MACHINE_FLAG_RRBM (1UL << 16) +#define MACHINE_FLAG_TLB_LC (1UL << 17) #define MACHINE_IS_VM (S390_lowcore.machine_flags & MACHINE_FLAG_VM) #define MACHINE_IS_KVM (S390_lowcore.machine_flags & MACHINE_FLAG_KVM) @@ -90,6 +91,7 @@ void create_mem_hole(struct mem_chunk mem_chunk[], unsigned long addr, #define MACHINE_HAS_TOPOLOGY (0) #define MACHINE_HAS_TE (0) #define MACHINE_HAS_RRBM (0) +#define MACHINE_HAS_TLB_LC (0) #else /* CONFIG_64BIT */ #define MACHINE_HAS_IEEE (1) #define MACHINE_HAS_CSP (1) @@ -102,6 +104,7 @@ void create_mem_hole(struct mem_chunk mem_chunk[], unsigned long addr, #define MACHINE_HAS_TOPOLOGY (S390_lowcore.machine_flags & MACHINE_FLAG_TOPOLOGY) #define MACHINE_HAS_TE (S390_lowcore.machine_flags & MACHINE_FLAG_TE) #define MACHINE_HAS_RRBM (S390_lowcore.machine_flags & MACHINE_FLAG_RRBM) +#define MACHINE_HAS_TLB_LC (S390_lowcore.machine_flags & MACHINE_FLAG_TLB_LC) #endif /* CONFIG_64BIT */ /* |