From: Anton Blanchard <anton@samba.org>
To: benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au,
mikey@neuling.org, cyrilbur@gmail.com
Cc: linuxppc-dev@lists.ozlabs.org
Subject: [PATCH 07/19] powerpc: Create mtmsrd_isync()
Date: Wed, 28 Oct 2015 11:50:55 +1100 [thread overview]
Message-ID: <1445993467-667-7-git-send-email-anton@samba.org> (raw)
In-Reply-To: <1445993467-667-1-git-send-email-anton@samba.org>
mtmsrd_isync() will do an mtmsrd followed by an isync on older
processors. On newer processors we avoid the isync via a feature fixup.
Signed-off-by: Anton Blanchard <anton@samba.org>
---
arch/powerpc/include/asm/reg.h | 8 ++++++++
arch/powerpc/kernel/process.c | 30 ++++++++++++++++++++++--------
2 files changed, 30 insertions(+), 8 deletions(-)
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index a908ada..987dac0 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -1193,12 +1193,20 @@
#define __mtmsrd(v, l) asm volatile("mtmsrd %0," __stringify(l) \
: : "r" (v) : "memory")
#define mtmsr(v) __mtmsrd((v), 0)
+#define __MTMSR "mtmsrd"
#else
#define mtmsr(v) asm volatile("mtmsr %0" : \
: "r" ((unsigned long)(v)) \
: "memory")
+#define __MTMSR "mtmsr"
#endif
+static inline void mtmsr_isync(unsigned long val)
+{
+ asm volatile(__MTMSR " %0; " ASM_FTR_IFCLR("isync", "nop", %1) : :
+ "r" (val), "i" (CPU_FTR_ARCH_206) : "memory");
+}
+
#define mfspr(rn) ({unsigned long rval; \
asm volatile("mfspr %0," __stringify(rn) \
: "=r" (rval)); rval;})
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index ef64219..5bf8ec2 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -130,7 +130,10 @@ void enable_kernel_fp(void)
check_if_tm_restore_required(current);
giveup_fpu(current);
} else {
- giveup_fpu(NULL); /* just enables FP for kernel */
+ u64 oldmsr = mfmsr();
+
+ if (!(oldmsr & MSR_FP))
+ mtmsr_isync(oldmsr | MSR_FP);
}
}
EXPORT_SYMBOL(enable_kernel_fp);
@@ -144,7 +147,10 @@ void enable_kernel_altivec(void)
check_if_tm_restore_required(current);
giveup_altivec(current);
} else {
- giveup_altivec_notask();
+ u64 oldmsr = mfmsr();
+
+ if (!(oldmsr & MSR_VEC))
+ mtmsr_isync(oldmsr | MSR_VEC);
}
}
EXPORT_SYMBOL(enable_kernel_altivec);
@@ -173,10 +179,14 @@ void enable_kernel_vsx(void)
{
WARN_ON(preemptible());
- if (current->thread.regs && (current->thread.regs->msr & MSR_VSX))
+ if (current->thread.regs && (current->thread.regs->msr & MSR_VSX)) {
giveup_vsx(current);
- else
- giveup_vsx(NULL); /* just enable vsx for kernel - force */
+ } else {
+ u64 oldmsr = mfmsr();
+
+ if (!(oldmsr & MSR_VSX))
+ mtmsr_isync(oldmsr | MSR_VSX);
+ }
}
EXPORT_SYMBOL(enable_kernel_vsx);
@@ -209,10 +219,14 @@ void enable_kernel_spe(void)
{
WARN_ON(preemptible());
- if (current->thread.regs && (current->thread.regs->msr & MSR_SPE))
+ if (current->thread.regs && (current->thread.regs->msr & MSR_SPE)) {
giveup_spe(current);
- else
- giveup_spe(NULL); /* just enable SPE for kernel - force */
+ } else {
+ u64 oldmsr = mfmsr();
+
+ if (!(oldmsr & MSR_SPE))
+ mtmsr_isync(oldmsr | MSR_SPE);
+ }
}
EXPORT_SYMBOL(enable_kernel_spe);
--
2.5.0
next prev parent reply other threads:[~2015-10-28 0:51 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-28 0:50 [PATCH 01/19] powerpc: Don't disable kernel FP/VMX/VSX MSR bits on context switch Anton Blanchard
2015-10-28 0:50 ` [PATCH 02/19] powerpc: Don't disable MSR bits in do_load_up_transact_*() functions Anton Blanchard
2015-10-28 0:50 ` [PATCH 03/19] powerpc: Create context switch helpers save_sprs() and restore_sprs() Anton Blanchard
2015-10-28 0:50 ` [PATCH 04/19] powerpc: Remove redundant mflr in _switch Anton Blanchard
2015-10-28 0:50 ` [PATCH 05/19] powerpc: Remove UP only lazy floating point and vector optimisations Anton Blanchard
2015-10-28 0:50 ` [PATCH 06/19] powerpc: Simplify TM restore checks Anton Blanchard
2015-10-28 0:50 ` Anton Blanchard [this message]
2015-10-28 0:50 ` [PATCH 08/19] powerpc: Remove NULL task struct pointer checks in FP and vector code Anton Blanchard
2015-10-28 0:50 ` [PATCH 09/19] powerpc: Move part of giveup_fpu,altivec,spe into c Anton Blanchard
2015-10-28 3:17 ` [PATCH 09/19] powerpc: Move part of giveup_fpu, altivec, spe " kbuild test robot
2015-10-28 0:50 ` [PATCH 10/19] powerpc: Move part of giveup_vsx " Anton Blanchard
2015-10-28 0:50 ` [PATCH 11/19] crypto: vmx: Only call enable_kernel_vsx() Anton Blanchard
2015-10-28 0:51 ` [PATCH 12/19] powerpc: Create msr_check_and_{set,clear}() Anton Blanchard
2015-10-28 0:51 ` [PATCH 13/19] powerpc: Create disable_kernel_{fp,altivec,vsx,spe}() Anton Blanchard
2015-10-28 0:51 ` [PATCH 14/19] powerpc: Add ppc_strict_facility_enable boot option Anton Blanchard
2015-10-28 0:51 ` [PATCH 15/19] powerpc: Remove fp_enable() and vec_enable(), use msr_check_and_{set, clear}() Anton Blanchard
2015-10-28 0:51 ` [PATCH 16/19] powerpc: create giveup_all() Anton Blanchard
2015-10-28 0:51 ` [PATCH 17/19] powerpc: create flush_all_to_thread() Anton Blanchard
2015-10-28 0:51 ` [PATCH 18/19] powerpc: Rearrange __switch_to() Anton Blanchard
2015-10-28 0:51 ` [PATCH 19/19] powerpc: clean up asm/switch_to.h Anton Blanchard
2015-10-28 3:19 ` kbuild test robot
2015-10-28 4:24 ` kbuild test robot
2015-10-29 0:43 [PATCH 00/19] Context switch improvements Anton Blanchard
2015-10-29 0:43 ` [PATCH 07/19] powerpc: Create mtmsrd_isync() Anton Blanchard
2015-12-01 11:23 ` Michael Ellerman
2015-12-01 23:25 ` Michael Ellerman
2017-09-02 3:44 ` Benjamin Herrenschmidt
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