diff options
| author | Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com> | 2020-03-05 23:02:50 +0300 |
|---|---|---|
| committer | Vineet Gupta <vgupta@synopsys.com> | 2020-03-16 20:23:44 +0300 |
| commit | 4827d0cf744e7e9cc73f10e1f4eaca904a3868c1 (patch) | |
| tree | 2b7f88fe8cb98dcba5aaffebf23bd07570ce6e27 /arch/arc/include/asm/entry-arcv2.h | |
| parent | 240c84b1c22c9912ed1c8a96251b44e85d2ca2ed (diff) | |
| download | linux-4827d0cf744e7e9cc73f10e1f4eaca904a3868c1.tar.xz | |
ARC: handle DSP presence in HW
When DSP extensions are present, some of the regular integer instructions
such as DIV, MACD etc are executed in the DSP unit with semantics alterable
by flags in DSP_CTRL aux register. This register is writable by userspace
and thus can potentially affect corresponding instructions in kernel code,
intentionally or otherwise. So safegaurd kernel by effectively disabling
DSP_CTRL upon bootup and every entry to kernel.
Do note that for this config we simply zero out the DSP_CTRL reg assuming
userspace doesn't really care about DSP. The next patch caters to the DSP
aware userspace where this reg is saved/restored upon kernel entry/exit.
Reviewed-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Diffstat (limited to 'arch/arc/include/asm/entry-arcv2.h')
| -rw-r--r-- | arch/arc/include/asm/entry-arcv2.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/arc/include/asm/entry-arcv2.h b/arch/arc/include/asm/entry-arcv2.h index 0b8b63d0bec1..dd6aa18b51ca 100644 --- a/arch/arc/include/asm/entry-arcv2.h +++ b/arch/arc/include/asm/entry-arcv2.h @@ -4,6 +4,7 @@ #define __ASM_ARC_ENTRY_ARCV2_H #include <asm/asm-offsets.h> +#include <asm/dsp-impl.h> #include <asm/irqflags-arcv2.h> #include <asm/thread_info.h> /* For THREAD_SIZE */ @@ -165,6 +166,8 @@ ST2 r58, r59, PT_r58 #endif + /* clobbers r10, r11 registers pair */ + DSP_SAVE_REGFILE_IRQ .endm /*------------------------------------------------------------------------*/ |