Hi Oliver, > From: Rashmica Gupta <rashmic...@gmail.com> > > Adds support for removing bolted (i.e kernel linear mapping) mappings > on powernv. This is needed to support memory hot unplug operations > which are required for the teardown of DAX/PMEM devices. > > Cc: Rashmica Gupta <rashmic...@gmail.com> > Cc: Anton Blanchard <an...@samba.org> > Signed-off-by: Oliver O'Halloran <ooh...@gmail.com> > --- > Could the original author of this add their S-o-b? I pulled it out of > Rashmica's memtrace patch, but I remember someone saying Anton wrote > it originally.
I did. Signed-off-by: Anton Blanchard <an...@samba.org> Anton > --- > arch/powerpc/mm/hash_native_64.c | 31 +++++++++++++++++++++++++++++++ > 1 file changed, 31 insertions(+) > > diff --git a/arch/powerpc/mm/hash_native_64.c > b/arch/powerpc/mm/hash_native_64.c index 65bb8f33b399..9ba91d4905a4 > 100644 --- a/arch/powerpc/mm/hash_native_64.c > +++ b/arch/powerpc/mm/hash_native_64.c > @@ -407,6 +407,36 @@ static void native_hpte_updateboltedpp(unsigned > long newpp, unsigned long ea, tlbie(vpn, psize, psize, ssize, 0); > } > > +/* > + * Remove a bolted kernel entry. Memory hotplug uses this. > + * > + * No need to lock here because we should be the only user. > + */ > +static int native_hpte_removebolted(unsigned long ea, int psize, int > ssize) +{ > + unsigned long vpn; > + unsigned long vsid; > + long slot; > + struct hash_pte *hptep; > + > + vsid = get_kernel_vsid(ea, ssize); > + vpn = hpt_vpn(ea, vsid, ssize); > + > + slot = native_hpte_find(vpn, psize, ssize); > + if (slot == -1) > + return -ENOENT; > + > + hptep = htab_address + slot; > + > + /* Invalidate the hpte */ > + hptep->v = 0; > + > + /* Invalidate the TLB */ > + tlbie(vpn, psize, psize, ssize, 0); > + return 0; > +} > + > + > static void native_hpte_invalidate(unsigned long slot, unsigned long > vpn, int bpsize, int apsize, int ssize, int local) > { > @@ -725,6 +755,7 @@ void __init hpte_init_native(void) > mmu_hash_ops.hpte_invalidate = native_hpte_invalidate; > mmu_hash_ops.hpte_updatepp = native_hpte_updatepp; > mmu_hash_ops.hpte_updateboltedpp = > native_hpte_updateboltedpp; > + mmu_hash_ops.hpte_removebolted = native_hpte_removebolted; > mmu_hash_ops.hpte_insert = native_hpte_insert; > mmu_hash_ops.hpte_remove = native_hpte_remove; > mmu_hash_ops.hpte_clear_all = native_hpte_clear;