diff options
| author | Huacai Chen <chenhc@lemote.com> | 2016-03-03 04:45:13 +0300 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2016-05-13 15:02:15 +0300 |
| commit | 1e820da3c9af4f5771d2ad47099919429b906ac6 (patch) | |
| tree | bb4782e16be098d8b8019bd881224183e724cbaf /arch/mips/Kconfig | |
| parent | 380cd582c08831217ae693c86411902e6300ba6b (diff) | |
| download | linux-1e820da3c9af4f5771d2ad47099919429b906ac6.tar.xz | |
MIPS: Loongson-3: Introduce CONFIG_LOONGSON3_ENHANCEMENT
New Loongson 3 CPU (since Loongson-3A R2, as opposed to Loongson-3A R1,
Loongson-3B R1 and Loongson-3B R2) has many enhancements, such as FTLB,
L1-VCache, EI/DI/Wait/Prefetch instruction, DSP/DSPv2 ASE, User Local
register, Read-Inhibit/Execute-Inhibit, SFB (Store Fill Buffer), Fast
TLB refill support, etc.
This patch introduce a config option, CONFIG_LOONGSON3_ENHANCEMENT, to
enable those enhancements which are not probed at run time. If you want
a generic kernel to run on all Loongson 3 machines, please say 'N'
here. If you want a high-performance kernel to run on new Loongson 3
machines only, please say 'Y' here.
Some additional explanations:
1) SFB locates between core and L1 cache, it causes memory access out
of order, so writel/outl (and other similar functions) need a I/O
reorder barrier.
2) Loongson 3 has a bug that di instruction can not save the irqflag,
so arch_local_irq_save() is modified. Since CPU_MIPSR2 is selected
by CONFIG_LOONGSON3_ENHANCEMENT, generic kernel doesn't use ei/di
at all.
3) CPU_HAS_PREFETCH is selected by CONFIG_LOONGSON3_ENHANCEMENT, so
MIPS_CPU_PREFETCH (used by uasm) probing is also put in this patch.
Signed-off-by: Huacai Chen <chenhc@lemote.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Steven J . Hill <sjhill@realitydiluted.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12755/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/Kconfig')
| -rw-r--r-- | arch/mips/Kconfig | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig index adcc97ea4392..d5c3621f0dd1 100644 --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -1360,6 +1360,24 @@ config CPU_LOONGSON3 The Loongson 3 processor implements the MIPS64R2 instruction set with many extensions. +config LOONGSON3_ENHANCEMENT + bool "New Loongson 3 CPU Enhancements" + default n + select CPU_MIPSR2 + select CPU_HAS_PREFETCH + depends on CPU_LOONGSON3 + help + New Loongson 3 CPU (since Loongson-3A R2, as opposed to Loongson-3A + R1, Loongson-3B R1 and Loongson-3B R2) has many enhancements, such as + FTLB, L1-VCache, EI/DI/Wait/Prefetch instruction, DSP/DSPv2 ASE, User + Local register, Read-Inhibit/Execute-Inhibit, SFB (Store Fill Buffer), + Fast TLB refill support, etc. + + This option enable those enhancements which are not probed at run + time. If you want a generic kernel to run on all Loongson 3 machines, + please say 'N' here. If you want a high-performance kernel to run on + new Loongson 3 machines only, please say 'Y' here. + config CPU_LOONGSON2E bool "Loongson 2E" depends on SYS_HAS_CPU_LOONGSON2E |