blob: 7556dad1bbce94acb5cc750d0a1220700338ce6b [file] [log] [blame]
From 45f2981546b25cf7e9144bef66ac6fadd90b20c2 Mon Sep 17 00:00:00 2001
From: "Aneesh Kumar K.V" <>
Date: Thu, 24 Oct 2019 15:05:41 +0530
Subject: [PATCH] powerpc/pseries: Don't fail hash page table insert for bolted
commit 75838a3290cd4ebbd1f567f310ba04b6ef017ce4 upstream.
If the hypervisor returned H_PTEG_FULL for H_ENTER hcall, retry a hash page table
insert by removing a random entry from the group.
After some runtime, it is very well possible to find all the 8 hash page table
entry slot in the hpte group used for mapping. Don't fail a bolted entry insert
in that case. With Storage class memory a user can find this error easily since
a namespace enable/disable is equivalent to memory add/remove.
This results in failures as reported below:
$ ndctl create-namespace -r region1 -t pmem -m devdax -a 65536 -s 100M
libndctl: ndctl_dax_enable: dax1.3: failed to enable
Error: namespace1.2: failed to enable
failed to create namespace: No such device or address
In kernel log we find the details as below:
Unable to create mapping for hot added memory 0xc000042006000000..0xc00004200d000000: -1
dax_pmem: probe of dax1.3 failed with error -14
This indicates that we failed to create a bolted hash table entry for direct-map
address backing the namespace.
We also observe failures such that not all namespaces will be enabled with
ndctl enable-namespace all command.
Signed-off-by: Aneesh Kumar K.V <>
Signed-off-by: Michael Ellerman <>
Signed-off-by: Paul Gortmaker <>
diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c
index 64340fc677bb..404ce65a34b4 100644
--- a/arch/powerpc/mm/book3s64/hash_utils.c
+++ b/arch/powerpc/mm/book3s64/hash_utils.c
@@ -297,7 +297,14 @@ int htab_bolt_mapping(unsigned long vstart, unsigned long vend,
ret = mmu_hash_ops.hpte_insert(hpteg, vpn, paddr, tprot,
HPTE_V_BOLTED, psize, psize,
+ if (ret == -1) {
+ /* Try to remove a non bolted entry */
+ ret = mmu_hash_ops.hpte_remove(hpteg);
+ if (ret != -1)
+ ret = mmu_hash_ops.hpte_insert(hpteg, vpn, paddr, tprot,
+ HPTE_V_BOLTED, psize, psize,
+ ssize);
+ }
if (ret < 0)