Commit Graph

6 Commits

Author SHA1 Message Date
Thomas Gleixner
ec8f24b7fa treewide: Add SPDX license identifier - Makefile/Kconfig
Add SPDX license identifiers to all Make/Kconfig files which:

 - Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21 10:50:46 +02:00
Nylon Chen
e2f3f8b4a4 nds32: support hardware prefetcher
We add a config for user to enable or disable this feature.
It can be used to control the hardware prefetch function.

Signed-off-by: Nylon Chen <nylon7@andestech.com>
Acked-by: Greentime Hu <greentime@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>
2018-11-22 18:13:51 +08:00
Vincent Chen
44e92e0364 nds32: support denormalized result through FP emulator
Currently, the nds32 FPU dose not support the arithmetic of denormalized
number. When the nds32 FPU finds the result of the instruction is a
denormlized number, the nds32 FPU considers it to be an underflow condition
and rounds the result to an appropriate number. It may causes some loss
of precision. This commit proposes a solution to re-execute the
instruction by the FPU emulator to enhance the precision. To transfer
calculations from user space to kernel space, this feature will enable
the underflow exception trap by default. Enabling this feature may cause
some side effects:
  1. Performance loss due to extra FPU exception
  2. Need another scheme to control real underflow trap
       A new parameter, UDF_trap, which is belong to FPU context is used
     to control underflow trap.

User can configure this feature via CONFIG_SUPPORT_DENORMAL_ARITHMETIC

Signed-off-by: Vincent Chen <vincentc@andestech.com>
Acked-by: Greentime Hu <greentime@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>
2018-11-22 18:13:27 +08:00
Vincent Chen
e46bf83c18 nds32: nds32 FPU port
This patch set contains basic components for supporting the nds32 FPU,
such as exception handlers and context switch for FPU registers. By
default, the lazy FPU scheme is supported and the user can configure it via
CONFIG_LZAY_FPU.

Signed-off-by: Vincent Chen <vincentc@andestech.com>
Acked-by: Greentime Hu <greentime@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>
2018-11-22 18:13:13 +08:00
Greentime Hu
b3b112bb06 nds32: Fix the allmodconfig build. To make sure CONFIG_CPU_LITTLE_ENDIAN is default y
This way we can build kernel with CONFIG_CPU_LITTLE_ENDIAN=y. Build allmodconfig
and allnoconfig are available too. It also fixes the endian mismatch issue
because AFLAGS and LDFLAGS is not passed correctly.

Signed-off-by: Vincent Ren-Wei Chen <vincentc@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>
2018-05-23 13:26:21 +08:00
Greentime Hu
e71ea3bada nds32: Build infrastructure
This patch adds Makefile, Kconfig and vmlinux.lds.S files required for building
an nds32 kernel.

Signed-off-by: Vincent Chen <vincentc@andestech.com>
Signed-off-by: Greentime Hu <greentime@andestech.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
2018-02-22 10:44:35 +08:00