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| author | Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> | 2018-03-23 05:56:27 +0100 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2018-03-23 10:48:03 +0100 |
| commit | a5d4b5891c2f1f865a2def1eb0030f534e77ff86 (patch) | |
| tree | 7c3f4cce6cc8156676b76a384d032145af3507bb /arch/powerpc/kvm | |
| parent | powerpc/mm/radix: Move the functions that does the actual tlbie closer (diff) | |
| download | linux-a5d4b5891c2f1f865a2def1eb0030f534e77ff86.tar.xz linux-a5d4b5891c2f1f865a2def1eb0030f534e77ff86.zip | |
powerpc/mm: Fixup tlbie vs store ordering issue on POWER9
On POWER9, under some circumstances, a broadcast TLB invalidation
might complete before all previous stores have drained, potentially
allowing stale stores from becoming visible after the invalidation.
This works around it by doubling up those TLB invalidations which was
verified by HW to be sufficient to close the risk window.
This will be documented in a yet-to-be-published errata.
Fixes: 1a472c9dba6b ("powerpc/mm/radix: Add tlbflush routines")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
[mpe: Enable the feature in the DT CPU features code for all Power9,
rename the feature to CPU_FTR_P9_TLBIE_BUG per benh.]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kvm')
| -rw-r--r-- | arch/powerpc/kvm/book3s_64_mmu_radix.c | 3 | ||||
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv_rm_mmu.c | 11 |
2 files changed, 14 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c index 0c854816e653..0837b9738d76 100644 --- a/arch/powerpc/kvm/book3s_64_mmu_radix.c +++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c @@ -157,6 +157,9 @@ static void kvmppc_radix_tlbie_page(struct kvm *kvm, unsigned long addr, asm volatile("ptesync": : :"memory"); asm volatile(PPC_TLBIE_5(%0, %1, 0, 0, 1) : : "r" (addr), "r" (kvm->arch.lpid) : "memory"); + if (cpu_has_feature(CPU_FTR_P9_TLBIE_BUG)) + asm volatile(PPC_TLBIE_5(%0, %1, 0, 0, 1) + : : "r" (addr), "r" (kvm->arch.lpid) : "memory"); asm volatile("ptesync": : :"memory"); } diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c index 8888e625a999..e1c083fbe434 100644 --- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c +++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c @@ -473,6 +473,17 @@ static void do_tlbies(struct kvm *kvm, unsigned long *rbvalues, trace_tlbie(kvm->arch.lpid, 0, rbvalues[i], kvm->arch.lpid, 0, 0, 0); } + + if (cpu_has_feature(CPU_FTR_P9_TLBIE_BUG)) { + /* + * Need the extra ptesync to make sure we don't + * re-order the tlbie + */ + asm volatile("ptesync": : :"memory"); + asm volatile(PPC_TLBIE_5(%0,%1,0,0,0) : : + "r" (rbvalues[0]), "r" (kvm->arch.lpid)); + } + asm volatile("eieio; tlbsync; ptesync" : : : "memory"); kvm->arch.tlbie_lock = 0; } else { |