diff options
| author | Nicholas Piggin <npiggin@gmail.com> | 2017-06-08 18:36:09 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-06-15 09:34:39 +0300 |
| commit | 07d2a628bc0008f90754ac7982289f6cb0f46cf8 (patch) | |
| tree | fa8554770bf35735a791fd798a2dc3bd8ab45807 /arch/powerpc/include/asm/ppc-opcode.h | |
| parent | 9145effd626d155484f73db24ab3e142ecda31db (diff) | |
| download | linux-07d2a628bc0008f90754ac7982289f6cb0f46cf8.tar.xz | |
powerpc/64s: Avoid cpabort in context switch when possible
The ISA v3.0B copy-paste facility only requires cpabort when switching
to a process that has foreign real addresses mapped (direct access to
accelerators), to clear a potential copy buffer filled by a previous
thread. There is no accelerator driver implemented yet, so cpabort can
be removed. It can be be re-added when a driver is implemented.
POWER9 DD1 requires the copy buffer to always be cleared on context
switch, but if accelerators are not in use, then an unpaired copy from
a dummy region is sufficient to clear data out of the copy buffer.
This increases context switch performance by about 5% on POWER9.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/include/asm/ppc-opcode.h')
| -rw-r--r-- | arch/powerpc/include/asm/ppc-opcode.h | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/arch/powerpc/include/asm/ppc-opcode.h b/arch/powerpc/include/asm/ppc-opcode.h index 3a8d278e7421..3b6bbf5a8683 100644 --- a/arch/powerpc/include/asm/ppc-opcode.h +++ b/arch/powerpc/include/asm/ppc-opcode.h @@ -189,8 +189,7 @@ /* sorted alphabetically */ #define PPC_INST_BHRBE 0x7c00025c #define PPC_INST_CLRBHRB 0x7c00035c -#define PPC_INST_COPY 0x7c00060c -#define PPC_INST_COPY_FIRST 0x7c20060c +#define PPC_INST_COPY 0x7c20060c #define PPC_INST_CP_ABORT 0x7c00068c #define PPC_INST_DCBA 0x7c0005ec #define PPC_INST_DCBA_MASK 0xfc0007fe @@ -223,8 +222,7 @@ #define PPC_INST_MSGSNDP 0x7c00011c #define PPC_INST_MTTMR 0x7c0003dc #define PPC_INST_NOP 0x60000000 -#define PPC_INST_PASTE 0x7c00070c -#define PPC_INST_PASTE_LAST 0x7c20070d +#define PPC_INST_PASTE 0x7c20070d #define PPC_INST_POPCNTB 0x7c0000f4 #define PPC_INST_POPCNTB_MASK 0xfc0007fe #define PPC_INST_POPCNTD 0x7c0003f4 @@ -392,6 +390,8 @@ /* Deal with instructions that older assemblers aren't aware of */ #define PPC_CP_ABORT stringify_in_c(.long PPC_INST_CP_ABORT) +#define PPC_COPY(a, b) stringify_in_c(.long PPC_INST_COPY | \ + ___PPC_RA(a) | ___PPC_RB(b)) #define PPC_DCBAL(a, b) stringify_in_c(.long PPC_INST_DCBAL | \ __PPC_RA(a) | __PPC_RB(b)) #define PPC_DCBZL(a, b) stringify_in_c(.long PPC_INST_DCBZL | \ |