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2019-03-23powerpc/hugetlb: Don't do runtime allocation of 16G pages in LPAR configurationAneesh Kumar K.V1-0/+8
commit 35f2806b481f5b9207f25e1886cba5d1c4d12cc7 upstream. We added runtime allocation of 16G pages in commit 4ae279c2c96a ("powerpc/mm/hugetlb: Allow runtime allocation of 16G.") That was done to enable 16G allocation on PowerNV and KVM config. In case of KVM config, we mostly would have the entire guest RAM backed by 16G hugetlb pages for this to work. PAPR do support partial backing of guest RAM with hugepages via ibm,expected#pages node of memory node in the device tree. This means rest of the guest RAM won't be backed by 16G contiguous pages in the host and hence a hash page table insertion can fail in such case. An example error message will look like hash-mmu: mm: Hashing failure ! EA=0x7efc00000000 access=0x8000000000000006 current=readback hash-mmu: trap=0x300 vsid=0x67af789 ssize=1 base psize=14 psize 14 pte=0xc000000400000386 readback[12260]: unhandled signal 7 at 00007efc00000000 nip 00000000100012d0 lr 000000001000127c code 2 This patch address that by preventing runtime allocation of 16G hugepages in LPAR config. To allocate 16G hugetlb one need to kernel command line hugepagesz=16G hugepages=<number of 16G pages> With radix translation mode we don't run into this issue. This change will prevent runtime allocation of 16G hugetlb pages on kvm with hash translation mode. However, with the current upstream it was observed that 16G hugetlbfs backed guest doesn't boot at all. We observe boot failure with the below message: [131354.647546] KVM: map_vrma at 0 failed, ret=-4 That means this patch is not resulting in an observable regression. Once we fix the boot issue with 16G hugetlb backed memory, we need to use ibm,expected#pages memory node attribute to indicate 16G page reservation to the guest. This will also enable partial backing of guest RAM with 16G pages. Fixes: 4ae279c2c96a ("powerpc/mm/hugetlb: Allow runtime allocation of 16G.") Cc: stable@vger.kernel.org # v4.14+ Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-15powerpc/radix: Fix kernel crash with mremap()Aneesh Kumar K.V1-15/+7
commit 579b9239c1f38665b21e8d0e6ee83ecc96dbd6bb upstream. With support for split pmd lock, we use pmd page pmd_huge_pte pointer to store the deposited page table. In those config when we move page tables we need to make sure we move the deposited page table to the correct pmd page. Otherwise this can result in crash when we withdraw of deposited page table because we can find the pmd_huge_pte NULL. eg: __split_huge_pmd+0x1070/0x1940 __split_huge_pmd+0xe34/0x1940 (unreliable) vma_adjust_trans_huge+0x110/0x1c0 __vma_adjust+0x2b4/0x9b0 __split_vma+0x1b8/0x280 __do_munmap+0x13c/0x550 sys_mremap+0x220/0x7e0 system_call+0x5c/0x70 Fixes: 675d995297d4 ("powerpc/book3s64: Enable split pmd ptlock.") Cc: stable@vger.kernel.org # v4.18+ Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-10-09mm: Preserve _PAGE_DEVMAP across mprotect() callsJan Kara1-2/+2
Currently _PAGE_DEVMAP bit is not preserved in mprotect(2) calls. As a result we will see warnings such as: BUG: Bad page map in process JobWrk0013 pte:800001803875ea25 pmd:7624381067 addr:00007f0930720000 vm_flags:280000f9 anon_vma: (null) mapping:ffff97f2384056f0 index:0 file:457-000000fe00000030-00000009-000000ca-00000001_2001.fileblock fault:xfs_filemap_fault [xfs] mmap:xfs_file_mmap [xfs] readpage: (null) CPU: 3 PID: 15848 Comm: JobWrk0013 Tainted: G W 4.12.14-2.g7573215-default #1 SLE12-SP4 (unreleased) Hardware name: Intel Corporation S2600WFD/S2600WFD, BIOS SE5C620.86B.01.00.0833.051120182255 05/11/2018 Call Trace: dump_stack+0x5a/0x75 print_bad_pte+0x217/0x2c0 ? enqueue_task_fair+0x76/0x9f0 _vm_normal_page+0xe5/0x100 zap_pte_range+0x148/0x740 unmap_page_range+0x39a/0x4b0 unmap_vmas+0x42/0x90 unmap_region+0x99/0xf0 ? vma_gap_callbacks_rotate+0x1a/0x20 do_munmap+0x255/0x3a0 vm_munmap+0x54/0x80 SyS_munmap+0x1d/0x30 do_syscall_64+0x74/0x150 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 ... when mprotect(2) gets used on DAX mappings. Also there is a wide variety of other failures that can result from the missing _PAGE_DEVMAP flag when the area gets used by get_user_pages() later. Fix the problem by including _PAGE_DEVMAP in a set of flags that get preserved by mprotect(2). Fixes: 69660fd797c3 ("x86, mm: introduce _PAGE_DEVMAP") Fixes: ebd31197931d ("powerpc/mm: Add devmap support for ppc64") Cc: <stable@vger.kernel.org> Signed-off-by: Jan Kara <jack@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2018-09-12KVM: PPC: Avoid marking DMA-mapped pages dirty in real modeAlexey Kardashevskiy1-1/+0
At the moment the real mode handler of H_PUT_TCE calls iommu_tce_xchg_rm() which in turn reads the old TCE and if it was a valid entry, marks the physical page dirty if it was mapped for writing. Since it is in real mode, realmode_pfn_to_page() is used instead of pfn_to_page() to get the page struct. However SetPageDirty() itself reads the compound page head and returns a virtual address for the head page struct and setting dirty bit for that kills the system. This adds additional dirty bit tracking into the MM/IOMMU API for use in the real mode. Note that this does not change how VFIO and KVM (in virtual mode) set this bit. The KVM (real mode) changes include: - use the lowest bit of the cached host phys address to carry the dirty bit; - mark pages dirty when they are unpinned which happens when the preregistered memory is released which always happens in virtual mode; - add mm_iommu_ua_mark_dirty_rm() helper to set delayed dirty bit; - change iommu_tce_xchg_rm() to take the kvm struct for the mm to use in the new mm_iommu_ua_mark_dirty_rm() helper; - move iommu_tce_xchg_rm() to book3s_64_vio_hv.c (which is the only caller anyway) to reduce the real mode KVM and IOMMU knowledge across different subsystems. This removes realmode_pfn_to_page() as it is not used anymore. While we at it, remove some EXPORT_SYMBOL_GPL() as that code is for the real mode only and modules cannot call it anyway. Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-08-23powerpc/mm/books3s: Add new pte bit to mark pte temporarily invalid.Aneesh Kumar K.V1-1/+17
When splitting a huge pmd pte, we need to mark the pmd entry invalid. We can do that by clearing _PAGE_PRESENT bit. But then that will be taken as a swap pte. In order to differentiate between the two use a software pte bit when invalidating. For regular pte, due to bd5050e38aec ("powerpc/mm/radix: Change pte relax sequence to handle nest MMU hang") we need to mark the pte entry invalid when relaxing access permission. Instead of marking pte_none which can result in different page table walk routines possibly skipping this pte entry, invalidate it but still keep it marked present. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-13powerpc/mm/book3s/radix: Add mapping statisticsAneesh Kumar K.V2-0/+10
Add statistics that show how memory is mapped within the kernel linear mapping. This is similar to commit 37cd944c8d8f ("s390/pgtable: add mapping statistics") We don't do this with Hash translation mode. Hash uses one size (mmu_linear_psize) to map the kernel linear mapping and we print the linear psize during boot as below. "Page orders: linear mapping = 24, virtual = 16, io = 16, vmemmap = 24" A sample output looks like: DirectMap4k: 0 kB DirectMap64k: 18432 kB DirectMap2M: 1030144 kB DirectMap1G: 11534336 kB Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-10powerpc/mm/hash: Remove unnecessary do { } while(0) loopAneesh Kumar K.V1-3/+2
Avoid coverity false warnings like: *** CID 187347: Control flow issues (UNREACHABLE) /arch/powerpc/mm/hash_native_64.c: 819 in native_flush_hash_range() 813 slot += hidx & _PTEIDX_GROUP_IX; 814 hptep = htab_address + slot; 815 want_v = hpte_encode_avpn(vpn, psize, ssize); 816 hpte_v = hpte_get_old_v(hptep); 817 818 if (!HPTE_V_COMPARE(hpte_v, want_v) || !(hpte_v & HPTE_V_VALID)) >>> CID 187347: Control flow issues (UNREACHABLE) Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-08-10powerpc/64s: move machine check SLB flushing to mm/slb.cNicholas Piggin1-0/+3
The machine check code that flushes and restores bolted segments in real mode belongs in mm/slb.c. This will also be used by pseries machine check and idle code in future changes. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-07-30powerpc/mm: Don't report PUDs as memory leaks when using kmemleakMichael Ellerman1-2/+21
Paul Menzel reported that kmemleak was producing reports such as: unreferenced object 0xc0000000f8b80000 (size 16384): comm "init", pid 1, jiffies 4294937416 (age 312.240s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<00000000d997deb7>] __pud_alloc+0x80/0x190 [<0000000087f2e8a3>] move_page_tables+0xbac/0xdc0 [<00000000091e51c2>] shift_arg_pages+0xc0/0x210 [<00000000ab88670c>] setup_arg_pages+0x22c/0x2a0 [<0000000060871529>] load_elf_binary+0x41c/0x1648 [<00000000ecd9d2d4>] search_binary_handler.part.11+0xbc/0x280 [<0000000034e0cdd7>] __do_execve_file.isra.13+0x73c/0x940 [<000000005f953a6e>] sys_execve+0x58/0x70 [<000000009700a858>] system_call+0x5c/0x70 Indicating that a PUD was being leaked. However what's really happening is that kmemleak is not able to recognise the references from the PGD to the PUD, because they are not fully qualified pointers. We can confirm that in xmon, eg: Find the task struct for pid 1 "init": 0:mon> P task_struct ->thread.ksp PID PPID S P CMD c0000001fe7c0000 c0000001fe803960 1 0 S 13 systemd Dump virtual address 0 to find the PGD: 0:mon> dv 0 c0000001fe7c0000 pgd @ 0xc0000000f8b01000 Dump the memory of the PGD: 0:mon> d c0000000f8b01000 c0000000f8b01000 00000000f8b90000 0000000000000000 |................| c0000000f8b01010 0000000000000000 0000000000000000 |................| c0000000f8b01020 0000000000000000 0000000000000000 |................| c0000000f8b01030 0000000000000000 00000000f8b80000 |................| ^^^^^^^^^^^^^^^^ There we can see the reference to our supposedly leaked PUD. But because it's missing the leading 0xc, kmemleak won't recognise it. We can confirm it's still in use by translating an address that is mapped via it: 0:mon> dv 7fff94000000 c0000001fe7c0000 pgd @ 0xc0000000f8b01000 pgdp @ 0xc0000000f8b01038 = 0x00000000f8b80000 <-- pudp @ 0xc0000000f8b81ff8 = 0x00000000037c4000 pmdp @ 0xc0000000037c5ca0 = 0x00000000fbd89000 ptep @ 0xc0000000fbd89000 = 0xc0800001d5ce0386 Maps physical address = 0x00000001d5ce0000 Flags = Accessed Dirty Read Write The fix is fairly simple. We need to tell kmemleak to ignore PUD allocations and never report them as leaks. We can also tell it not to scan the PGD, because it will never find pointers in there. However it will still notice if we allocate a PGD and then leak it. Reported-by: Paul Menzel <pmenzel@molgen.mpg.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Tested-by: Paul Menzel <pmenzel@molgen.mpg.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-07-30powerpc: split asm/tlbflush.hChristophe Leroy2-0/+36
Split asm/tlbflush.h into: asm/nohash/tlbflush.h asm/book3s/32/tlbflush.h asm/book3s/64/tlbflush.h (already existing) Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-07-30powerpc/book3s: Remove PPC_PIN_SIZEChristophe Leroy1-5/+0
PPC_PIN_SIZE is specific to the 44x and is defined in mmu.h Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-07-30powerpc: move ASM_CONST and stringify_in_c() into asm-const.hChristophe Leroy3-1/+5
This patch moves ASM_CONST() and stringify_in_c() into dedicated asm-const.h, then cleans all related inclusions. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> [mpe: asm-compat.h should include asm-const.h] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-07-30powerpc/405: move PPC405_ERR77 in asm-405.hChristophe Leroy1-2/+0
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-07-24powerpc/mm/hash: Add hpte_get_old_v and use that instead of opencodingAneesh Kumar K.V1-0/+10
No functional change Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-07-19Merge branch 'topic/ppc-kvm' into nextMichael Ellerman4-55/+7
Merge in some commits we're sharing with the KVM tree. I manually propagated the change from commit d3d4ffaae439 ("powerpc/powernv/ioda2: Reduce upper limit for DMA window size") into pci-ioda-tce.c. Conflicts: arch/powerpc/include/asm/cputable.h arch/powerpc/platforms/powernv/pci-ioda.c arch/powerpc/platforms/powernv/pci.h
2018-07-16powerpc/64s: Remove POWER9 DD1 supportNicholas Piggin4-55/+7
POWER9 DD1 was never a product. It is no longer supported by upstream firmware, and it is not effectively supported in Linux due to lack of testing. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Michael Ellerman <mpe@ellerman.id.au> [mpe: Remove arch_make_huge_pte() entirely] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-26powerpc/mm/32: Fix pgtable_page_dtor callAneesh Kumar K.V1-1/+0
Commit 667416f38554 ("powerpc/mm: Fix kernel crash on page table free") added a call for pgtable_page_dtor in the rcu page table free routine. We missed the fact that for 32 bit platforms we did call the 'dtor' early. Drop the extra call for pgtable_page_dtor. We remove the call from __pte_free_tlb so that we do the page table free and 'dtor' call together. This should help when we switch these platforms to pte fragments. Fixes: 667416f38554 ("powerpc/mm: Fix kernel crash on page table free") Reported-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-20powerpc/mm/hash/4k: Free hugetlb page table caches correctly.Aneesh Kumar K.V4-0/+36
With 4k page size for hugetlb we allocate hugepage directories from its on slab cache. With patch 0c4d26802 ("powerpc/book3s64/mm: Simplify the rcu callback for page table free") we missed to free these allocated hugepd tables. Update pgtable_free to handle hugetlb hugepd directory table. Fixes: 0c4d268029bf ("powerpc/book3s64/mm: Simplify the rcu callback for page table free") Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> [mpe: Add CONFIG_HUGETLB_PAGE guard to fix build break] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-08mm: introduce ARCH_HAS_PTE_SPECIALLaurent Dufour1-3/+0
Currently the PTE special supports is turned on in per architecture header files. Most of the time, it is defined in arch/*/include/asm/pgtable.h depending or not on some other per architecture static definition. This patch introduce a new configuration variable to manage this directly in the Kconfig files. It would later replace __HAVE_ARCH_PTE_SPECIAL. Here notes for some architecture where the definition of __HAVE_ARCH_PTE_SPECIAL is not obvious: arm __HAVE_ARCH_PTE_SPECIAL which is currently defined in arch/arm/include/asm/pgtable-3level.h which is included by arch/arm/include/asm/pgtable.h when CONFIG_ARM_LPAE is set. So select ARCH_HAS_PTE_SPECIAL if ARM_LPAE. powerpc __HAVE_ARCH_PTE_SPECIAL is defined in 2 files: - arch/powerpc/include/asm/book3s/64/pgtable.h - arch/powerpc/include/asm/pte-common.h The first one is included if (PPC_BOOK3S & PPC64) while the second is included in all the other cases. So select ARCH_HAS_PTE_SPECIAL all the time. sparc: __HAVE_ARCH_PTE_SPECIAL is defined if defined(__sparc__) && defined(__arch64__) which are defined through the compiler in sparc/Makefile if !SPARC32 which I assume to be if SPARC64. So select ARCH_HAS_PTE_SPECIAL if SPARC64 There is no functional change introduced by this patch. Link: http://lkml.kernel.org/r/1523433816-14460-2-git-send-email-ldufour@linux.vnet.ibm.com Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com> Suggested-by: Jerome Glisse <jglisse@redhat.com> Reviewed-by: Jerome Glisse <jglisse@redhat.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: David S. Miller <davem@davemloft.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Albert Ou <albert@sifive.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: David Rientjes <rientjes@google.com> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Christophe LEROY <christophe.leroy@c-s.fr> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-03powerpc/64s/radix: optimise pte_updateNicholas Piggin1-12/+13
Implementing pte_update with pte_xchg (which uses cmpxchg) is inefficient. A single larx/stcx. works fine, no need for the less efficient cmpxchg sequence. Then remove the memory barriers from the operation. There is a requirement for TLB flushing to load mm_cpumask after the store that reduces pte permissions, which is moved into the TLB flush code. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03powerpc/64s/radix: avoid ptesync after set_pte and ptep_set_access_flagsNicholas Piggin1-1/+18
The ISA suggests ptesync after setting a pte, to prevent a table walk initiated by a subsequent access from missing that store and causing a spurious fault. This is an architectual allowance that allows an implementation's page table walker to be incoherent with the store queue. However there is no correctness problem in taking a spurious fault in userspace -- the kernel copes with these at any time, so the updated pte will be found eventually. Spurious kernel faults on vmap memory must be avoided, so a ptesync is put into flush_cache_vmap. On POWER9 so far I have not found a measurable window where this can result in more minor faults, so as an optimisation, remove the costly ptesync from pte updates. If an implementation benefits from ptesync, it would be better to add it back in update_mmu_cache, so it's not done for things like fork(2). fork --fork --exec benchmark improved 5.2% (12400->13100). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03powerpc/64s/radix: make ptep_get_and_clear_full non-atomic for the full caseNicholas Piggin1-8/+2
This matches other architectures, when we know there will be no further accesses to the address (e.g., for teardown), page table entries can be cleared non-atomically. The comments about NMMU are bogus: all MMU notifiers (including NMMU) are released at this point, with their TLBs flushed. An NMMU access at this point would be a bug. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03powerpc/64s/radix: do not flush TLB on spurious faultNicholas Piggin1-1/+11
In the case of a spurious fault (which can happen due to a race with another thread that changes the page table), the default Linux mm code calls flush_tlb_page for that address. This is not required because the pte will be re-fetched. Hash does not wire this up to a hardware TLB flush for this reason. This patch avoids the flush for radix. >From Power ISA v3.0B, p.1090: Setting a Reference or Change Bit or Upgrading Access Authority (PTE Subject to Atomic Hardware Updates) If the only change being made to a valid PTE that is subject to atomic hardware updates is to set the Refer- ence or Change bit to 1 or to add access authorities, a simpler sequence suffices because the translation hardware will refetch the PTE if an access is attempted for which the only problems were reference and/or change bits needing to be set or insufficient access authority. The nest MMU on POWER9 does not re-fetch the PTE after such an access attempt before faulting, so address spaces with a coprocessor attached will continue to flush in these cases. This reduces tlbies for a kernel compile workload from 0.95M to 0.90M. fork --fork --exec benchmark improved 0.5% (12300->12400). Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03powerpc/mm/radix: Change pte relax sequence to handle nest MMU hangAneesh Kumar K.V1-0/+2
When relaxing access (read -> read_write update), pte needs to be marked invalid to handle a nest MMU bug. We also need to do a tlb flush after the pte is marked invalid before updating the pte with new access bits. We also move tlb flush to platform specific __ptep_set_access_flags. This will help us to gerid of unnecessary tlb flush on BOOK3S 64 later. We don't do that in this patch. This also helps in avoiding multiple tlbies with coprocessor attached. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03powerpc/mm: Change function prototypeAneesh Kumar K.V3-7/+11
In later patch, we use the vma and psize to do tlb flush. Do the prototype update in separate patch to make the review easy. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03powerpc/mm/radix: Move function from radix.h to pgtable-radix.cAneesh Kumar K.V1-28/+3
In later patch we will update them which require them to be moved to pgtable-radix.c. Keeping the function in radix.h results in compile warning as below. ./arch/powerpc/include/asm/book3s/64/radix.h: In function ‘radix__ptep_set_access_flags’: ./arch/powerpc/include/asm/book3s/64/radix.h:196:28: error: dereferencing pointer to incomplete type ‘struct vm_area_struct’ struct mm_struct *mm = vma->vm_mm; ^~ ./arch/powerpc/include/asm/book3s/64/radix.h:204:6: error: implicit declaration of function ‘atomic_read’; did you mean ‘__atomic_load’? [-Werror=implicit-function-declaration] atomic_read(&mm->context.copros) > 0) { ^~~~~~~~~~~ __atomic_load ./arch/powerpc/include/asm/book3s/64/radix.h:204:21: error: dereferencing pointer to incomplete type ‘struct mm_struct’ atomic_read(&mm->context.copros) > 0) { Instead of fixing header dependencies, we move the function to pgtable-radix.c Also the function is now large to be a static inline . Doing the move in separate patch helps in review. No functional change in this patch. Only code movement. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-06-03Merge branch 'topic/ppc-kvm' into nextMichael Ellerman1-0/+7
Merge in some commits we're sharing with the kvm-ppc tree.
2018-06-01powerpc/mm: Fix kernel crash on page table freeAneesh Kumar K.V1-0/+1
Fix the below crash on Book3E 64. pgtable_page_dtor expects struct page *arg. Also call the destructor on non book3s platforms correctly. This frees up the split PTL locks correctly if we had allocated them before. Call Trace: .kmem_cache_free+0x9c/0x44c (unreliable) .ptlock_free+0x1c/0x30 .tlb_remove_table+0xdc/0x224 .free_pgd_range+0x298/0x500 .shift_arg_pages+0x10c/0x1e0 .setup_arg_pages+0x200/0x25c .load_elf_binary+0x450/0x16c8 .search_binary_handler.part.11+0x9c/0x248 .do_execveat_common.isra.13+0x868/0xc18 .run_init_process+0x34/0x4c .try_to_run_init_process+0x1c/0x68 .kernel_init+0xdc/0x130 .ret_from_kernel_thread+0x58/0x7c Fixes: 702346768 ("powerpc/mm/nohash: Remove pte fragment dependency from nohash") Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-17powerpc/mm/radix: implement LPID based TLB flushes to be used by KVMNicholas Piggin1-0/+7
Implement a local TLB flush for invalidating an LPID with variants for process or partition scope. And a global TLB flush for invalidating a partition scoped page of an LPID. These will be used by KVM in subsequent patches. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-15powerpc/mm: Use page fragments for allocation page table at PMD levelAneesh Kumar K.V3-17/+5
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-15powerpc/mm: Implement helpers for pagetable fragment support at PMD levelAneesh Kumar K.V7-0/+25
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-15powerpc/book3s64/mm: Simplify the rcu callback for page table freeAneesh Kumar K.V2-5/+15
Instead of encoding shift in the table address, use an enumerated index value. This allow us to do different things in the callback for pte and pmd. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-05-15powerpc/mm/book3s64/4k: Switch 4k pagesize config to use pagetable fragmentAneesh Kumar K.V3-31/+7
4K config use one full page at level 4 of the pagetable. Add support for single fragment allocation in pagetable fragment code and and use that for 4K config. This makes both 4k and 64k use the same code path. Later we will switch pmd to use the page table fragment code. This is done only for 64bit platforms which is using page table fragment support. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-04-04powerpc/mm/radix: Update pte fragment count from 16 to 256 on radixAneesh Kumar K.V3-6/+15
With split PTL (page table lock) config, we allocate the level 4 (leaf) page table using pte fragment framework instead of slab cache like other levels. This was done to enable us to have split page table lock at the level 4 of the page table. We use page->plt backing the all the level 4 pte fragment for the lock. Currently with Radix, we use only 16 fragments out of the allocated page. In radix each fragment is 256 bytes which means we use only 4k out of the allocated 64K page wasting 60k of the allocated memory. This was done earlier to keep it closer to hash. This patch update the pte fragment count to 256, thereby using the full 64K page and reducing the memory usage. Performance tests shows really low impact even with THP disabled. With THP disabled we will be contenting further less on level 4 ptl and hence the impact should be further low. 256 threads: without patch (10 runs of ./ebizzy -m -n 1000 -s 131072 -S 100) median = 15678.5 stdev = 42.1209 with patch: median = 15354 stdev = 194.743 This is with THP disabled. With THP enabled the impact of the patch will be less. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-31Merge branch 'topic/paca' into nextMichael Ellerman2-2/+2
Bring in yet another series that touches KVM code, and might need to be merged into the kvm-ppc branch to resolve conflicts. This required some changes in pnv_power9_force_smt4_catch/release() due to the paca array becomming an array of pointers.
2018-03-30powerpc/mm/hash: Don't memset pgd table if not neededAneesh Kumar K.V1-1/+11
We need to zero-out pgd table only if we share the slab cache with pud/pmd level caches. With the support of 4PB, we don't share the slab cache anymore. Instead of removing the code completely hide it within an #ifdef. We don't need to do this with any other page table level, because they all allocate table of double the size and we take of initializing the first half corrrectly during page table zap. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> [mpe: Consolidate multiple #if / #ifdef into one] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-30powerpc/mm/hash64: Increase the VA rangeAneesh Kumar K.V1-1/+1
This patch increases the max virtual (effective) address value to 4PB. With 4K page size config we continue to limit ourself to 64TB. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> [mpe: Keep the H_PGTABLE_RANGE test, update it to work] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-30powerpc/mm: Add support for handling > 512TB address in SLB missAneesh Kumar K.V3-1/+44
For addresses above 512TB we allocate additional mmu contexts. To make it all easy, addresses above 512TB are handled with IR/DR=1 and with stack frame setup. The mmu_context_t is also updated to track the new extended_ids. To support upto 4PB we need a total 8 contexts. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> [mpe: Minor formatting tweaks and comment wording, switch BUG to WARN in get_ea_context().] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-30powerpc/mm/keys: Move pte bits to correct headersAneesh Kumar K.V3-19/+15
Memory keys are supported only with hash translation mode. Instead of using #ifdef in generic code move the key related pte bits to respective headers Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-30powerpc/mm: Pass node id into create_section_mappingNicholas Piggin2-2/+2
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Move __map_kernel_page_nid() inside #ifdef SPARSEMEM_VMEMMAP] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-28Merge branch 'fixes' into nextMichael Ellerman2-3/+3
Merge our fixes branch from the 4.16 cycle. There were a number of important fixes merged, in particular some Power9 workarounds that we want in next for testing purposes. There's also been some conflicting changes in the CPU features code which are best merged and tested before going upstream.
2018-03-23powerpc/mm/radix: Remove unused codeAneesh Kumar K.V1-3/+0
These function are not used in the code. Remove them. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-23powerpc/mm: Add tracking of the number of coprocessors using a contextBenjamin Herrenschmidt1-0/+3
Currently, when using coprocessors (which use the Nest MMU), we simply increment the active_cpu count to force all TLB invalidations to be come broadcast. Unfortunately, due to an errata in POWER9, we will need to know more specifically that coprocessors are in use. This maintains a separate copros counter in the MMU context for that purpose. NB. The commit mentioned in the fixes tag below is not at fault for the bug we're fixing in this commit and the next, but this fix applies on top the infrastructure it introduced. Fixes: 03b8abedf4f4 ("cxl: Enable global TLBIs for cxl contexts") Cc: stable@vger.kernel.org # v4.15+ Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-13powerpc/mm/slice: implement a slice mask cacheNicholas Piggin1-0/+18
Calculating the slice mask can become a signifcant overhead for get_unmapped_area. This patch adds a struct slice_mask for each page size in the mm_context, and keeps these in synch with the slices psize arrays and slb_addr_limit. On Book3S/64 this adds 288 bytes to the mm_context_t for the slice mask caches. On POWER8, this increases vfork+exec+exit performance by 9.9% and reduces time to mmap+munmap a 64kB page by 28%. Reduces time to mmap+munmap by about 10% on 8xx. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-06powerpc/mm/slice: Allow up to 64 low slicesChristophe Leroy1-1/+2
While the implementation of the "slices" address space allows a significant amount of high slices, it limits the number of low slices to 16 due to the use of a single u64 low_slices_psize element in struct mm_context_t On the 8xx, the minimum slice size is the size of the area covered by a single PMD entry, ie 4M in 4K pages mode and 64M in 16K pages mode. This means we could have at least 64 slices. In order to override this limitation, this patch switches the handling of low_slices_psize to char array as done already for high_slices_psize. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-06powerpc/mm/slice: create header files dedicated to slicesChristophe Leroy1-0/+27
In preparation for the following patch which will enhance 'slices' for supporting PPC32 in order to fix an issue on hugepages on 8xx, this patch takes out of page*.h all bits related to 'slices' and put them into newly created slice.h header files. While common parts go into asm/slice.h, subarch specific parts go into respective books3s/64/slice.c and nohash/64/slice.c 'slices' Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-02-13powerpc/mm/hash64: Zero PGD pages on allocationAneesh Kumar K.V1-2/+8
On powerpc we allocate page table pages from slab caches of different sizes. Currently we have a constructor that zeroes out the objects when we allocate them for the first time. We expect the objects to be zeroed out when we free the the object back to slab cache. This happens in the unmap path. For hugetlb pages we call huge_pte_get_and_clear() to do that. With the current configuration of page table size, both PUD and PGD level tables are allocated from the same slab cache. At the PUD level, we use the second half of the table to store the slot information. But we never clear that when unmapping. When such a freed object is then allocated for a PGD page, the second half of the page table page will not be zeroed as expected. This results in a kernel crash. Fix it by always clearing PGD pages when they're allocated. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> [mpe: Change log wording and formatting, add whitespace] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-02-13powerpc/mm/hash64: Store the slot information at the right offset for hugetlbAneesh Kumar K.V3-6/+8
The hugetlb pte entries are at the PMD and PUD level, so we can't use PTRS_PER_PTE to find the second half of the page table. Use the right offset for PUD/PMD to get to the second half of the table. Fixes: bf9a95f9a648 ("powerpc: Free up four 64K PTE bits in 64K backed HPTE pages") Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Reviewed-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-02-13powerpc/mm/hash64: Allocate larger PMD table if hugetlb config is enabledAneesh Kumar K.V2-2/+3
We use the second half of the page table to store slot information, so we must allocate it always if hugetlb is possible. Fixes: bf9a95f9a648 ("powerpc: Free up four 64K PTE bits in 64K backed HPTE pages") Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Reviewed-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-02-13powerpc/mm: Fix crashes with 16G huge pagesAneesh Kumar K.V5-3/+21
To support memory keys, we moved the hash pte slot information to the second half of the page table. This was ok with PTE entries at level 4 (PTE page) and level 3 (PMD). We already allocate larger page table pages at those levels to accomodate extra details. For level 4 we already have the extra space which was used to track 4k hash page table entry details and at level 3 the extra space was allocated to track the THP details. With hugetlbfs PTE, we used this extra space at the PMD level to store the slot details. But we also support hugetlbfs PTE at PUD level for 16GB pages and PUD level page didn't allocate extra space. This resulted in memory corruption. Fix this by allocating extra space at PUD level when HUGETLB is enabled. Fixes: bf9a95f9a648 ("powerpc: Free up four 64K PTE bits in 64K backed HPTE pages") Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Reviewed-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>