[PATCH] powerpc: remove fpscr use from [kvm_]cvt_{fd,df}
Benjamin Herrenschmidt
benh at kernel.crashing.org
Tue Aug 24 15:11:58 EST 2010
On Mon, 2010-08-23 at 10:23 +1000, Michael Neuling wrote:
> > Neither lfs nor stfs touch the fpscr, so remove the restore/save of it
> > around them.
>
> Do some 32 bit processors need this?
>
> In 32 bit before the merge, we use to have code that did:
>
> #if defined(CONFIG_4xx) || defined(CONFIG_E500)
> #define cvt_fd without save/restore fpscr
> #else
> #define cvt_fd with save/restore fpscr
> #end if
>
> Kumar; does this ring any bells?
I don't see anything in the various 440 docs I have at hand that would
hint at lfd/stfs adffecting FPSCR.
Cheers,
Ben.
> (The addition of this predates even bitkeeper)
>
> Mikey
> >
> > Signed-off-by: Andreas Schwab <schwab at linux-m68k.org>
> > ---
> > arch/powerpc/include/asm/kvm_fpu.h | 4 +-
> > arch/powerpc/include/asm/system.h | 4 +-
> > arch/powerpc/kernel/align.c | 4 +-
> > arch/powerpc/kernel/fpu.S | 10 -------
> > arch/powerpc/kvm/book3s_paired_singles.c | 44 +++++++++++++---------------
> -
> > arch/powerpc/kvm/fpu.S | 8 -----
> > 6 files changed, 26 insertions(+), 48 deletions(-)
> >
> > diff --git a/arch/powerpc/include/asm/kvm_fpu.h b/arch/powerpc/include/asm/kv
> m_fpu.h
> > index c3d4f05..92daae1 100644
> > --- a/arch/powerpc/include/asm/kvm_fpu.h
> > +++ b/arch/powerpc/include/asm/kvm_fpu.h
> > @@ -82,7 +82,7 @@ FPD_THREE_IN(fmadd)
> > FPD_THREE_IN(fnmsub)
> > FPD_THREE_IN(fnmadd)
> >
> > -extern void kvm_cvt_fd(u32 *from, u64 *to, u64 *fpscr);
> > -extern void kvm_cvt_df(u64 *from, u32 *to, u64 *fpscr);
> > +extern void kvm_cvt_fd(u32 *from, u64 *to);
> > +extern void kvm_cvt_df(u64 *from, u32 *to);
> >
> > #endif
> > diff --git a/arch/powerpc/include/asm/system.h b/arch/powerpc/include/asm/sys
> tem.h
> > index 6c294ac..0b3fe78 100644
> > --- a/arch/powerpc/include/asm/system.h
> > +++ b/arch/powerpc/include/asm/system.h
> > @@ -154,8 +154,8 @@ extern void enable_kernel_spe(void);
> > extern void giveup_spe(struct task_struct *);
> > extern void load_up_spe(struct task_struct *);
> > extern int fix_alignment(struct pt_regs *);
> > -extern void cvt_fd(float *from, double *to, struct thread_struct *thread);
> > -extern void cvt_df(double *from, float *to, struct thread_struct *thread);
> > +extern void cvt_fd(float *from, double *to);
> > +extern void cvt_df(double *from, float *to);
> >
> > #ifndef CONFIG_SMP
> > extern void discard_lazy_cpu_state(void);
> > diff --git a/arch/powerpc/kernel/align.c b/arch/powerpc/kernel/align.c
> > index b876e98..8184ee9 100644
> > --- a/arch/powerpc/kernel/align.c
> > +++ b/arch/powerpc/kernel/align.c
> > @@ -889,7 +889,7 @@ int fix_alignment(struct pt_regs *regs)
> > #ifdef CONFIG_PPC_FPU
> > preempt_disable();
> > enable_kernel_fp();
> > - cvt_df(&data.dd, (float *)&data.v[4], ¤t->thread)
> ;
> > + cvt_df(&data.dd, (float *)&data.v[4]);
> > preempt_enable();
> > #else
> > return 0;
> > @@ -933,7 +933,7 @@ int fix_alignment(struct pt_regs *regs)
> > #ifdef CONFIG_PPC_FPU
> > preempt_disable();
> > enable_kernel_fp();
> > - cvt_fd((float *)&data.v[4], &data.dd, ¤t->thread);
> > + cvt_fd((float *)&data.v[4], &data.dd);
> > preempt_enable();
> > #else
> > return 0;
> > diff --git a/arch/powerpc/kernel/fpu.S b/arch/powerpc/kernel/fpu.S
> > index fc8f5b1..e86c040 100644
> > --- a/arch/powerpc/kernel/fpu.S
> > +++ b/arch/powerpc/kernel/fpu.S
> > @@ -163,24 +163,14 @@ END_FTR_SECTION_IFSET(CPU_FTR_VSX)
> > /*
> > * These are used in the alignment trap handler when emulating
> > * single-precision loads and stores.
> > - * We restore and save the fpscr so the task gets the same result
> > - * and exceptions as if the cpu had performed the load or store.
> > */
> >
> > _GLOBAL(cvt_fd)
> > - lfd 0,THREAD_FPSCR(r5) /* load up fpscr value */
> > - MTFSF_L(0)
> > lfs 0,0(r3)
> > stfd 0,0(r4)
> > - mffs 0
> > - stfd 0,THREAD_FPSCR(r5) /* save new fpscr value */
> > blr
> >
> > _GLOBAL(cvt_df)
> > - lfd 0,THREAD_FPSCR(r5) /* load up fpscr value */
> > - MTFSF_L(0)
> > lfd 0,0(r3)
> > stfs 0,0(r4)
> > - mffs 0
> > - stfd 0,THREAD_FPSCR(r5) /* save new fpscr value */
> > blr
> > diff --git a/arch/powerpc/kvm/book3s_paired_singles.c b/arch/powerpc/kvm/book
> 3s_paired_singles.c
> > index 474f2e2..35a701f 100644
> > --- a/arch/powerpc/kvm/book3s_paired_singles.c
> > +++ b/arch/powerpc/kvm/book3s_paired_singles.c
> > @@ -159,7 +159,7 @@
> >
> > static inline void kvmppc_sync_qpr(struct kvm_vcpu *vcpu, int rt)
> > {
> > - kvm_cvt_df(&vcpu->arch.fpr[rt], &vcpu->arch.qpr[rt], &vcpu->arch.fpscr)
> ;
> > + kvm_cvt_df(&vcpu->arch.fpr[rt], &vcpu->arch.qpr[rt]);
> > }
> >
> > static void kvmppc_inject_pf(struct kvm_vcpu *vcpu, ulong eaddr, bool is_sto
> re)
> > @@ -204,7 +204,7 @@ static int kvmppc_emulate_fpr_load(struct kvm_run *run, s
> truct kvm_vcpu *vcpu,
> > /* put in registers */
> > switch (ls_type) {
> > case FPU_LS_SINGLE:
> > - kvm_cvt_fd((u32*)tmp, &vcpu->arch.fpr[rs], &vcpu->arch.fpscr);
> > + kvm_cvt_fd((u32*)tmp, &vcpu->arch.fpr[rs]);
> > vcpu->arch.qpr[rs] = *((u32*)tmp);
> > break;
> > case FPU_LS_DOUBLE:
> > @@ -230,7 +230,7 @@ static int kvmppc_emulate_fpr_store(struct kvm_run *run,
> struct kvm_vcpu *vcpu,
> >
> > switch (ls_type) {
> > case FPU_LS_SINGLE:
> > - kvm_cvt_df(&vcpu->arch.fpr[rs], (u32*)tmp, &vcpu->arch.fpscr);
> > + kvm_cvt_df(&vcpu->arch.fpr[rs], (u32*)tmp);
> > val = *((u32*)tmp);
> > len = sizeof(u32);
> > break;
> > @@ -296,7 +296,7 @@ static int kvmppc_emulate_psq_load(struct kvm_run *run, s
> truct kvm_vcpu *vcpu,
> > emulated = EMULATE_DONE;
> >
> > /* put in registers */
> > - kvm_cvt_fd(&tmp[0], &vcpu->arch.fpr[rs], &vcpu->arch.fpscr);
> > + kvm_cvt_fd(&tmp[0], &vcpu->arch.fpr[rs]);
> > vcpu->arch.qpr[rs] = tmp[1];
> >
> > dprintk(KERN_INFO "KVM: PSQ_LD [0x%x, 0x%x] at 0x%lx (%d)\n", tmp[0],
> > @@ -314,7 +314,7 @@ static int kvmppc_emulate_psq_store(struct kvm_run *run,
> struct kvm_vcpu *vcpu,
> > u32 tmp[2];
> > int len = w ? sizeof(u32) : sizeof(u64);
> >
> > - kvm_cvt_df(&vcpu->arch.fpr[rs], &tmp[0], &vcpu->arch.fpscr);
> > + kvm_cvt_df(&vcpu->arch.fpr[rs], &tmp[0]);
> > tmp[1] = vcpu->arch.qpr[rs];
> >
> > r = kvmppc_st(vcpu, &addr, len, tmp, true);
> > @@ -516,9 +516,9 @@ static int kvmppc_ps_three_in(struct kvm_vcpu *vcpu, bool
> rc,
> > WARN_ON(rc);
> >
> > /* PS0 */
> > - kvm_cvt_df(&fpr[reg_in1], &ps0_in1, &vcpu->arch.fpscr);
> > - kvm_cvt_df(&fpr[reg_in2], &ps0_in2, &vcpu->arch.fpscr);
> > - kvm_cvt_df(&fpr[reg_in3], &ps0_in3, &vcpu->arch.fpscr);
> > + kvm_cvt_df(&fpr[reg_in1], &ps0_in1);
> > + kvm_cvt_df(&fpr[reg_in2], &ps0_in2);
> > + kvm_cvt_df(&fpr[reg_in3], &ps0_in3);
> >
> > if (scalar & SCALAR_LOW)
> > ps0_in2 = qpr[reg_in2];
> > @@ -529,7 +529,7 @@ static int kvmppc_ps_three_in(struct kvm_vcpu *vcpu, bool
> rc,
> > ps0_in1, ps0_in2, ps0_in3, ps0_out);
> >
> > if (!(scalar & SCALAR_NO_PS0))
> > - kvm_cvt_fd(&ps0_out, &fpr[reg_out], &vcpu->arch.fpscr);
> > + kvm_cvt_fd(&ps0_out, &fpr[reg_out]);
> >
> > /* PS1 */
> > ps1_in1 = qpr[reg_in1];
> > @@ -566,12 +566,12 @@ static int kvmppc_ps_two_in(struct kvm_vcpu *vcpu, bool
> rc,
> > WARN_ON(rc);
> >
> > /* PS0 */
> > - kvm_cvt_df(&fpr[reg_in1], &ps0_in1, &vcpu->arch.fpscr);
> > + kvm_cvt_df(&fpr[reg_in1], &ps0_in1);
> >
> > if (scalar & SCALAR_LOW)
> > ps0_in2 = qpr[reg_in2];
> > else
> > - kvm_cvt_df(&fpr[reg_in2], &ps0_in2, &vcpu->arch.fpscr);
> > + kvm_cvt_df(&fpr[reg_in2], &ps0_in2);
> >
> > func(&vcpu->arch.fpscr, &ps0_out, &ps0_in1, &ps0_in2);
> >
> > @@ -579,7 +579,7 @@ static int kvmppc_ps_two_in(struct kvm_vcpu *vcpu, bool r
> c,
> > dprintk(KERN_INFO "PS2 ps0 -> f(0x%x, 0x%x) = 0x%x\n",
> > ps0_in1, ps0_in2, ps0_out);
> >
> > - kvm_cvt_fd(&ps0_out, &fpr[reg_out], &vcpu->arch.fpscr);
> > + kvm_cvt_fd(&ps0_out, &fpr[reg_out]);
> > }
> >
> > /* PS1 */
> > @@ -615,13 +615,13 @@ static int kvmppc_ps_one_in(struct kvm_vcpu *vcpu, bool
> rc,
> > WARN_ON(rc);
> >
> > /* PS0 */
> > - kvm_cvt_df(&fpr[reg_in], &ps0_in, &vcpu->arch.fpscr);
> > + kvm_cvt_df(&fpr[reg_in], &ps0_in);
> > func(&vcpu->arch.fpscr, &ps0_out, &ps0_in);
> >
> > dprintk(KERN_INFO "PS1 ps0 -> f(0x%x) = 0x%x\n",
> > ps0_in, ps0_out);
> >
> > - kvm_cvt_fd(&ps0_out, &fpr[reg_out], &vcpu->arch.fpscr);
> > + kvm_cvt_fd(&ps0_out, &fpr[reg_out]);
> >
> > /* PS1 */
> > ps1_in = qpr[reg_in];
> > @@ -671,7 +671,7 @@ int kvmppc_emulate_paired_single(struct kvm_run *run, str
> uct kvm_vcpu *vcpu)
> > #ifdef DEBUG
> > for (i = 0; i < ARRAY_SIZE(vcpu->arch.fpr); i++) {
> > u32 f;
> > - kvm_cvt_df(&vcpu->arch.fpr[i], &f, &vcpu->arch.fpscr);
> > + kvm_cvt_df(&vcpu->arch.fpr[i], &f);
> > dprintk(KERN_INFO "FPR[%d] = 0x%x / 0x%llx QPR[%d] = 0x%x\n"
> ,
> > i, f, vcpu->arch.fpr[i], i, vcpu->arch.qpr[i]);
> > }
> > @@ -796,8 +796,7 @@ int kvmppc_emulate_paired_single(struct kvm_run *run, str
> uct kvm_vcpu *vcpu)
> > vcpu->arch.fpr[ax_rd] = vcpu->arch.fpr[ax_ra];
> > /* vcpu->arch.qpr[ax_rd] = vcpu->arch.fpr[ax_rb]; */
> > kvm_cvt_df(&vcpu->arch.fpr[ax_rb],
> > - &vcpu->arch.qpr[ax_rd],
> > - &vcpu->arch.fpscr);
> > + &vcpu->arch.qpr[ax_rd]);
> > break;
> > case OP_4X_PS_MERGE01:
> > WARN_ON(rcomp);
> > @@ -808,19 +807,16 @@ int kvmppc_emulate_paired_single(struct kvm_run *run, s
> truct kvm_vcpu *vcpu)
> > WARN_ON(rcomp);
> > /* vcpu->arch.fpr[ax_rd] = vcpu->arch.qpr[ax_ra]; */
> > kvm_cvt_fd(&vcpu->arch.qpr[ax_ra],
> > - &vcpu->arch.fpr[ax_rd],
> > - &vcpu->arch.fpscr);
> > + &vcpu->arch.fpr[ax_rd]);
> > /* vcpu->arch.qpr[ax_rd] = vcpu->arch.fpr[ax_rb]; */
> > kvm_cvt_df(&vcpu->arch.fpr[ax_rb],
> > - &vcpu->arch.qpr[ax_rd],
> > - &vcpu->arch.fpscr);
> > + &vcpu->arch.qpr[ax_rd]);
> > break;
> > case OP_4X_PS_MERGE11:
> > WARN_ON(rcomp);
> > /* vcpu->arch.fpr[ax_rd] = vcpu->arch.qpr[ax_ra]; */
> > kvm_cvt_fd(&vcpu->arch.qpr[ax_ra],
> > - &vcpu->arch.fpr[ax_rd],
> > - &vcpu->arch.fpscr);
> > + &vcpu->arch.fpr[ax_rd]);
> > vcpu->arch.qpr[ax_rd] = vcpu->arch.qpr[ax_rb];
> > break;
> > }
> > @@ -1255,7 +1251,7 @@ int kvmppc_emulate_paired_single(struct kvm_run *run, s
> truct kvm_vcpu *vcpu)
> > #ifdef DEBUG
> > for (i = 0; i < ARRAY_SIZE(vcpu->arch.fpr); i++) {
> > u32 f;
> > - kvm_cvt_df(&vcpu->arch.fpr[i], &f, &vcpu->arch.fpscr);
> > + kvm_cvt_df(&vcpu->arch.fpr[i], &f);
> > dprintk(KERN_INFO "FPR[%d] = 0x%x\n", i, f);
> > }
> > #endif
> > diff --git a/arch/powerpc/kvm/fpu.S b/arch/powerpc/kvm/fpu.S
> > index cb34bbe..bf68d59 100644
> > --- a/arch/powerpc/kvm/fpu.S
> > +++ b/arch/powerpc/kvm/fpu.S
> > @@ -273,19 +273,11 @@ FPD_THREE_IN(fnmsub)
> > FPD_THREE_IN(fnmadd)
> >
> > _GLOBAL(kvm_cvt_fd)
> > - lfd 0,0(r5) /* load up fpscr value */
> > - MTFSF_L(0)
> > lfs 0,0(r3)
> > stfd 0,0(r4)
> > - mffs 0
> > - stfd 0,0(r5) /* save new fpscr value */
> > blr
> >
> > _GLOBAL(kvm_cvt_df)
> > - lfd 0,0(r5) /* load up fpscr value */
> > - MTFSF_L(0)
> > lfd 0,0(r3)
> > stfs 0,0(r4)
> > - mffs 0
> > - stfd 0,0(r5) /* save new fpscr value */
> > blr
> > --
> > 1.7.2.2
> >
> >
> > --
> > Andreas Schwab, schwab at linux-m68k.org
> > GPG Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5
> > "And now for something completely different."
> > _______________________________________________
> > Linuxppc-dev mailing list
> > Linuxppc-dev at lists.ozlabs.org
> > https://lists.ozlabs.org/listinfo/linuxppc-dev
> >
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