From ef2f826c8f2ff1e4215968042139604633581a13 Mon Sep 17 00:00:00 2001 From: Huacai Chen Date: Thu, 26 Jun 2014 11:41:31 +0800 Subject: [PATCH] MIPS: Loongson-3: Enable the COP2 usage Loongson-3 has some specific instructions (MMI/SIMD) in coprocessor 2. COP2 isn't independent because it share COP1 (FPU)'s registers. This patch enable the COP2 usage so user-space programs can use the MMI/SIMD instructions. When COP2 exception happens, we enable both COP1 (FPU) and COP2, only in this way the fp context can be saved and restored correctly. Signed-off-by: Huacai Chen Cc: John Crispin Cc: Steven J. Hill Cc: Aurelien Jarno Cc: linux-mips@linux-mips.org Cc: Fuxin Zhang Cc: Zhangjin Wu Patchwork: https://patchwork.linux-mips.org/patch/7189/ Signed-off-by: Ralf Baechle --- arch/mips/include/asm/cop2.h | 8 ++++ arch/mips/loongson/loongson-3/Makefile | 2 +- arch/mips/loongson/loongson-3/cop2-ex.c | 63 +++++++++++++++++++++++++ 3 files changed, 72 insertions(+), 1 deletion(-) create mode 100644 arch/mips/loongson/loongson-3/cop2-ex.c diff --git a/arch/mips/include/asm/cop2.h b/arch/mips/include/asm/cop2.h index c1516cc0285f..d0352983b94d 100644 --- a/arch/mips/include/asm/cop2.h +++ b/arch/mips/include/asm/cop2.h @@ -32,6 +32,14 @@ extern void nlm_cop2_restore(struct nlm_cop2_state *); #define cop2_present 1 #define cop2_lazy_restore 0 +#elif defined(CONFIG_CPU_LOONGSON3) + +#define cop2_save(r) +#define cop2_restore(r) + +#define cop2_present 1 +#define cop2_lazy_restore 1 + #else #define cop2_present 0 diff --git a/arch/mips/loongson/loongson-3/Makefile b/arch/mips/loongson/loongson-3/Makefile index 471b0f2af079..b4df775b9f30 100644 --- a/arch/mips/loongson/loongson-3/Makefile +++ b/arch/mips/loongson/loongson-3/Makefile @@ -1,7 +1,7 @@ # # Makefile for Loongson-3 family machines # -obj-y += irq.o +obj-y += irq.o cop2-ex.o obj-$(CONFIG_SMP) += smp.o diff --git a/arch/mips/loongson/loongson-3/cop2-ex.c b/arch/mips/loongson/loongson-3/cop2-ex.c new file mode 100644 index 000000000000..9182e8d2967c --- /dev/null +++ b/arch/mips/loongson/loongson-3/cop2-ex.c @@ -0,0 +1,63 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2014 Lemote Corporation. + * written by Huacai Chen + * + * based on arch/mips/cavium-octeon/cpu.c + * Copyright (C) 2009 Wind River Systems, + * written by Ralf Baechle + */ +#include +#include +#include + +#include +#include +#include +#include + +static int loongson_cu2_call(struct notifier_block *nfb, unsigned long action, + void *data) +{ + int fpu_enabled; + int fr = !test_thread_flag(TIF_32BIT_FPREGS); + + switch (action) { + case CU2_EXCEPTION: + preempt_disable(); + fpu_enabled = read_c0_status() & ST0_CU1; + if (!fr) + set_c0_status(ST0_CU1 | ST0_CU2); + else + set_c0_status(ST0_CU1 | ST0_CU2 | ST0_FR); + enable_fpu_hazard(); + KSTK_STATUS(current) |= (ST0_CU1 | ST0_CU2); + if (fr) + KSTK_STATUS(current) |= ST0_FR; + else + KSTK_STATUS(current) &= ~ST0_FR; + /* If FPU is enabled, we needn't init or restore fp */ + if(!fpu_enabled) { + set_thread_flag(TIF_USEDFPU); + if (!used_math()) { + _init_fpu(); + set_used_math(); + } else + _restore_fp(current); + } + preempt_enable(); + + return NOTIFY_STOP; /* Don't call default notifier */ + } + + return NOTIFY_OK; /* Let default notifier send signals */ +} + +static int __init loongson_cu2_setup(void) +{ + return cu2_notifier(loongson_cu2_call, 0); +} +early_initcall(loongson_cu2_setup); -- 2.20.1