From: David Daney <david.da...@cavium.com> commit a36d8225bceba4b7be47ade34d175945f85cffbc upstream
Some versions of the assembler will not assemble CFC1 for OCTEON, so override the ISA for these. Add r4k_fpu.o to handle low level FPU initialization. Modify octeon_switch.S to save the FPU registers. And include r4k_switch.S to pick up more FPU support. Get rid of "#define cpu_has_fpu 0" Signed-off-by: David Daney <david.da...@cavium.com> Signed-off-by: Andreas Herrmann <andreas.herrm...@caviumnetworks.com> Cc: linux-m...@linux-mips.org Cc: James Hogan <james.ho...@imgtec.com> Cc: k...@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/7006/ Signed-off-by: Ralf Baechle <r...@linux-mips.org> Signed-off-by: Abhishek Paliwal <abhishek.pali...@aricent.com> --- .../asm/mach-cavium-octeon/cpu-feature-overrides.h | 1 - arch/mips/kernel/Makefile | 2 +- arch/mips/kernel/branch.c | 6 +- arch/mips/kernel/octeon_switch.S | 85 ++++++++++++++++------ arch/mips/kernel/r4k_switch.S | 3 + arch/mips/math-emu/cp1emu.c | 12 ++- 6 files changed, 80 insertions(+), 29 deletions(-) diff --git a/arch/mips/include/asm/mach-cavium-octeon/cpu-feature-overrides.h b/arch/mips/include/asm/mach-cavium-octeon/cpu-feature-overrides.h index 94ed063..cf80228 100644 --- a/arch/mips/include/asm/mach-cavium-octeon/cpu-feature-overrides.h +++ b/arch/mips/include/asm/mach-cavium-octeon/cpu-feature-overrides.h @@ -22,7 +22,6 @@ #define cpu_has_3k_cache 0 #define cpu_has_4k_cache 0 #define cpu_has_tx39_cache 0 -#define cpu_has_fpu 0 #define cpu_has_counter 1 #define cpu_has_watch 1 #define cpu_has_divec 1 diff --git a/arch/mips/kernel/Makefile b/arch/mips/kernel/Makefile index 26c6175..f76cf1e 100644 --- a/arch/mips/kernel/Makefile +++ b/arch/mips/kernel/Makefile @@ -42,7 +42,7 @@ obj-$(CONFIG_CPU_R4K_FPU) += r4k_fpu.o r4k_switch.o obj-$(CONFIG_CPU_R3000) += r2300_fpu.o r2300_switch.o obj-$(CONFIG_CPU_R6000) += r6000_fpu.o r4k_switch.o obj-$(CONFIG_CPU_TX39XX) += r2300_fpu.o r2300_switch.o -obj-$(CONFIG_CPU_CAVIUM_OCTEON) += octeon_switch.o +obj-$(CONFIG_CPU_CAVIUM_OCTEON) += r4k_fpu.o octeon_switch.o obj-$(CONFIG_SMP) += smp.o obj-$(CONFIG_SMP_UP) += smp-up.o diff --git a/arch/mips/kernel/branch.c b/arch/mips/kernel/branch.c index 4d78bf4..418865f 100644 --- a/arch/mips/kernel/branch.c +++ b/arch/mips/kernel/branch.c @@ -366,7 +366,11 @@ int __compute_return_epc_for_insn(struct pt_regs *regs, case cop1_op: preempt_disable(); if (is_fpu_owner()) - asm volatile("cfc1\t%0,$31" : "=r" (fcr31)); + asm volatile( + ".set push\n" + "\t.set mips1\n" + "\tcfc1\t%0,$31\n" + "\t.set pop" : "=r" (fcr31)); else fcr31 = current->thread.fpu.fcr31; preempt_enable(); diff --git a/arch/mips/kernel/octeon_switch.S b/arch/mips/kernel/octeon_switch.S index 029e002..0f1163a 100644 --- a/arch/mips/kernel/octeon_switch.S +++ b/arch/mips/kernel/octeon_switch.S @@ -10,24 +10,11 @@ * Copyright (C) 2000 MIPS Technologies, Inc. * written by Carsten Langgaard, carst...@mips.com */ -#include <asm/asm.h> -#include <asm/cachectl.h> -#include <asm/fpregdef.h> -#include <asm/mipsregs.h> -#include <asm/asm-offsets.h> -#include <asm/pgtable-bits.h> -#include <asm/regdef.h> -#include <asm/stackframe.h> -#include <asm/thread_info.h> - -#include <asm/asmmacro.h> - -/* - * Offset to the current process status flags, the first 32 bytes of the - * stack are not used. - */ -#define ST_OFF (_THREAD_SIZE - 32 - PT_SIZE + PT_STATUS) - +#define USE_ALTERNATE_RESUME_IMPL 1 + .set push + .set arch=mips64r2 +#include "r4k_switch.S" + .set pop /* * task_struct *resume(task_struct *prev, task_struct *next, * struct thread_info *next_ti, int usedfpu) @@ -39,7 +26,62 @@ LONG_S t1, THREAD_STATUS(a0) cpu_save_nonscratch a0 LONG_S ra, THREAD_REG31(a0) + /* + * check if we need to save FPU registers + */ + PTR_L t3, TASK_THREAD_INFO(a0) + LONG_L t0, TI_FLAGS(t3) + li t1, _TIF_USEDFPU + and t2, t0, t1 + beqz t2, 1f + nor t1, zero, t1 + + and t0, t0, t1 + LONG_S t0, TI_FLAGS(t3) + /* + * clear saved user stack CU1 bit + */ + LONG_L t0, ST_OFF(t3) + li t1, ~ST0_CU1 + and t0, t0, t1 + LONG_S t0, ST_OFF(t3) + + .set push + .set arch=mips64r2 + fpu_save_double a0 t0 t1 # c0_status passed in t0 + # clobbers t1 + + .set pop +1: + + /* check if we need to save COP2 registers */ + PTR_L t2, TASK_THREAD_INFO(a0) + LONG_L t0, ST_OFF(t2) + bbit0 t0, 30, 1f + + /* Disable COP2 in the stored process state */ + li t1, ST0_CU2 + xor t0, t1 + LONG_S t0, ST_OFF(t2) + + /* Enable COP2 so we can save it */ + mfc0 t0, CP0_STATUS + or t0, t1 + mtc0 t0, CP0_STATUS + + /* Save COP2 */ + daddu a0, THREAD_CP2 + jal octeon_cop2_save + dsubu a0, THREAD_CP2 + + /* Disable COP2 now that we are done */ + mfc0 t0, CP0_STATUS + li t1, ST0_CU2 + xor t0, t1 + mtc0 t0, CP0_STATUS + +1: #if CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE > 0 /* Check if we need to store CVMSEG state */ mfc0 t0, $11,7 /* CvmMemCtl */ @@ -85,12 +127,7 @@ move $28, a2 cpu_restore_nonscratch a1 -#if (_THREAD_SIZE - 32) < 0x8000 - PTR_ADDIU t0, $28, _THREAD_SIZE - 32 -#else - PTR_LI t0, _THREAD_SIZE - 32 - PTR_ADDU t0, $28 -#endif + PTR_ADDU t0, $28, _THREAD_SIZE - 32 set_saved_sp t0, t1, t2 mfc0 t1, CP0_STATUS /* Do we really need this? */ diff --git a/arch/mips/kernel/r4k_switch.S b/arch/mips/kernel/r4k_switch.S index cc78dd9..8a4f9a5 100644 --- a/arch/mips/kernel/r4k_switch.S +++ b/arch/mips/kernel/r4k_switch.S @@ -28,6 +28,7 @@ */ #define ST_OFF (_THREAD_SIZE - 32 - PT_SIZE + PT_STATUS) +#ifndef USE_ALTERNATE_RESUME_IMPL /* * FPU context is saved iff the process has used it's FPU in the current * time slice as indicated by _TIF_USEDFPU. In any case, the CU1 bit for user @@ -119,6 +120,8 @@ jr ra END(resume) +#endif /* USE_ALTERNATE_RESUME_IMPL */ + /* * Save a thread's fp context. */ diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c index 0b4e2e3..edb110c 100644 --- a/arch/mips/math-emu/cp1emu.c +++ b/arch/mips/math-emu/cp1emu.c @@ -559,7 +559,11 @@ int mm_isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn, case mm_bc1t_op: preempt_disable(); if (is_fpu_owner()) - asm volatile("cfc1\t%0,$31" : "=r" (fcr31)); + asm volatile( + ".set push\n" + " .set mips1\n" + " cfc1 %0,$31\n" + " .set pop" : "=r" (fcr31)); else fcr31 = current->thread.fpu.fcr31; preempt_enable(); @@ -817,7 +821,11 @@ static int isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn, if (insn.i_format.rs == bc_op) { preempt_disable(); if (is_fpu_owner()) - asm volatile("cfc1\t%0,$31" : "=r" (fcr31)); + asm volatile( + ".set push\n" + "\t.set mips1\n" + "\tcfc1\t%0,$31\n" + "\t.set pop" : "=r" (fcr31)); else fcr31 = current->thread.fpu.fcr31; preempt_enable(); -- 1.8.1.4 "DISCLAIMER: This message is proprietary to Aricent and is intended solely for the use of the individual to whom it is addressed. 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