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2020-12-03powerpc/64s: Tidy machine check SLB loggingNicholas Piggin1-18/+21
Since ISA v3.0, SLB no longer uses the slb_cache, and stab_rr is no longer correlated with SLB allocation. Move those to pre-3.0. While here, improve some alignments and reduce whitespace. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201128070728.825934-9-npiggin@gmail.com
2020-11-26powerpc/64s: Trim offlined CPUs from mm_cpumasksNicholas Piggin1-0/+20
When offlining a CPU, powerpc/64s does not flush TLBs, rather it just leaves the CPU set in mm_cpumasks, so it continues to receive TLBIEs to manage its TLBs. However the exit_flush_lazy_tlbs() function expects that after returning, all CPUs (except self) have flushed TLBs for that mm, in which case TLBIEL can be used for this flush. This breaks for offline CPUs because they don't get the IPI to flush their TLB. This can lead to stale translations. Fix this by clearing the CPU from mm_cpumasks, then flushing all TLBs before going offline. These offlined CPU bits stuck in the cpumask also prevents the cpumask from being trimmed back to local mode, which means continual broadcast IPIs or TLBIEs are needed for TLB flushing. This patch prevents that situation too. A cast of many were involved in working this out, but in particular Milton, Aneesh, Paul made key discoveries. Fixes: 0cef77c7798a7 ("powerpc/64s/radix: flush remote CPUs out of single-threaded mm_cpumask") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Debugged-by: Milton Miller <miltonm@us.ibm.com> Debugged-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Debugged-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201126102530.691335-5-npiggin@gmail.com
2020-11-26powerpc/64s/pseries: Fix hash tlbiel_all_isa300 for guest kernelsNicholas Piggin1-7/+14
tlbiel_all() can not be usable in !HVMODE when running hash presently, remove HV privileged flushes when running in guest to make it usable. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201126102530.691335-3-npiggin@gmail.com
2020-11-26powerpc/64s: Fix hash ISA v3.0 TLBIEL instruction generationNicholas Piggin1-1/+1
A typo has the R field of the instruction assigned by lucky dip a la register allocator. Fixes: d4748276ae14c ("powerpc/64s: Improve local TLB flush for boot and MCE on POWER9") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201126102530.691335-2-npiggin@gmail.com
2020-11-19powerpc/book3s64/hash: Drop WARN_ON in hash__remove_section_mapping()David Hildenbrand1-1/+0
The single caller (arch_remove_linear_mapping()) prints a proper warning when this function fails. No need to eventually crash the kernel - let's drop this WARN_ON. Suggested-by: Oscar Salvador <osalvador@suse.de> Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201111145322.15793-7-david@redhat.com
2020-11-19powerpc/mm: Update tlbiel loop on POWER10Aneesh Kumar K.V1-7/+16
With POWER10, single tlbiel instruction invalidates all the congruence class of the TLB and hence we need to issue only one tlbiel with SET=0. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201007053305.232879-1-aneesh.kumar@linux.ibm.com
2020-11-19powerpc/mm: Move setting PTE specific flags to pfn_pmd()Aneesh Kumar K.V1-1/+7
powerpc used to set the PTE specific flags in set_pte_at(). That is different from other architectures. To be consistent with other architectures powerpc updated pfn_pte() to set _PAGE_PTE in commit 379c926d6334 ("powerpc/mm: move setting pte specific flags to pfn_pte") That commit didn't do the same for pfn_pmd() because we expect pmd_mkhuge() to do that. But as per Linus that is a bad rule: The rule that you must use "pmd_mkhuge()" seems _completely_ wrong. The only valid use to ever make a pmd out of a pfn is to make a huge-page. Hence update pfn_pmd() to set _PAGE_PTE. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201022091115.39568-1-aneesh.kumar@linux.ibm.com
2020-10-16Merge tag 'powerpc-5.10-1' of ↵Linus Torvalds7-28/+47
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: - A series from Nick adding ARCH_WANT_IRQS_OFF_ACTIVATE_MM & selecting it for powerpc, as well as a related fix for sparc. - Remove support for PowerPC 601. - Some fixes for watchpoints & addition of a new ptrace flag for detecting ISA v3.1 (Power10) watchpoint features. - A fix for kernels using 4K pages and the hash MMU on bare metal Power9 systems with > 16TB of RAM, or RAM on the 2nd node. - A basic idle driver for shallow stop states on Power10. - Tweaks to our sched domains code to better inform the scheduler about the hardware topology on Power9/10, where two SMT4 cores can be presented by firmware as an SMT8 core. - A series doing further reworks & cleanups of our EEH code. - Addition of a filter for RTAS (firmware) calls done via sys_rtas(), to prevent root from overwriting kernel memory. - Other smaller features, fixes & cleanups. Thanks to: Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V, Athira Rajeev, Biwen Li, Cameron Berkenpas, Cédric Le Goater, Christophe Leroy, Christoph Hellwig, Colin Ian King, Daniel Axtens, David Dai, Finn Thain, Frederic Barrat, Gautham R. Shenoy, Greg Kurz, Gustavo Romero, Ira Weiny, Jason Yan, Joel Stanley, Jordan Niethe, Kajol Jain, Konrad Rzeszutek Wilk, Laurent Dufour, Leonardo Bras, Liu Shixin, Luca Ceresoli, Madhavan Srinivasan, Mahesh Salgaonkar, Nathan Lynch, Nicholas Mc Guire, Nicholas Piggin, Nick Desaulniers, Oliver O'Halloran, Pedro Miraglia Franco de Carvalho, Pratik Rajesh Sampat, Qian Cai, Qinglang Miao, Ravi Bangoria, Russell Currey, Satheesh Rajendran, Scott Cheloha, Segher Boessenkool, Srikar Dronamraju, Stan Johnson, Stephen Kitt, Stephen Rothwell, Thiago Jung Bauermann, Tyrel Datwyler, Vaibhav Jain, Vaidyanathan Srinivasan, Vasant Hegde, Wang Wensheng, Wolfram Sang, Yang Yingliang, zhengbin. * tag 'powerpc-5.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (228 commits) Revert "powerpc/pci: unmap legacy INTx interrupts when a PHB is removed" selftests/powerpc: Fix eeh-basic.sh exit codes cpufreq: powernv: Fix frame-size-overflow in powernv_cpufreq_reboot_notifier powerpc/time: Make get_tb() common to PPC32 and PPC64 powerpc/time: Make get_tbl() common to PPC32 and PPC64 powerpc/time: Remove get_tbu() powerpc/time: Avoid using get_tbl() and get_tbu() internally powerpc/time: Make mftb() common to PPC32 and PPC64 powerpc/time: Rename mftbl() to mftb() powerpc/32s: Remove #ifdef CONFIG_PPC_BOOK3S_32 in head_book3s_32.S powerpc/32s: Rename head_32.S to head_book3s_32.S powerpc/32s: Setup the early hash table at all time. powerpc/time: Remove ifdef in get_dec() and set_dec() powerpc: Remove get_tb_or_rtc() powerpc: Remove __USE_RTC() powerpc: Tidy up a bit after removal of PowerPC 601. powerpc: Remove support for PowerPC 601 powerpc: Remove PowerPC 601 powerpc: Drop SYNC_601() ISYNC_601() and SYNC() powerpc: Remove CONFIG_PPC601_SYNC_FIX ...
2020-10-14arch, drivers: replace for_each_membock() with for_each_mem_range()Mike Rapoport2-13/+13
There are several occurrences of the following pattern: for_each_memblock(memory, reg) { start = __pfn_to_phys(memblock_region_memory_base_pfn(reg); end = __pfn_to_phys(memblock_region_memory_end_pfn(reg)); /* do something with start and end */ } Using for_each_mem_range() iterator is more appropriate in such cases and allows simpler and cleaner code. [akpm@linux-foundation.org: fix arch/arm/mm/pmsa-v7.c build] [rppt@linux.ibm.com: mips: fix cavium-octeon build caused by memblock refactoring] Link: http://lkml.kernel.org/r/20200827124549.GD167163@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Daniel Axtens <dja@axtens.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Emil Renner Berthing <kernel@esmil.dk> Cc: Hari Bathini <hbathini@linux.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: https://lkml.kernel.org/r/20200818151634.14343-13-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-08powerpc/lmb-size: Use addr #size-cells value when fetching lmb-sizeAneesh Kumar K.V1-3/+4
Make it consistent with other usages. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201007114836.282468-5-aneesh.kumar@linux.ibm.com
2020-10-08powerpc/book3s64/radix: Make radix_mem_block_size 64bitAneesh Kumar K.V1-1/+1
Similar to commit 89c140bbaeee ("pseries: Fix 64 bit logical memory block panic") make sure different variables tracking lmb_size are updated to be 64 bit. Fixes: af9d00e93a4f ("powerpc/mm/radix: Create separate mappings for hot-plugged memory") Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201007114836.282468-4-aneesh.kumar@linux.ibm.com
2020-10-06powerpc/64s: Add cp_abort after tlbiel to invalidate copy-buffer addressNicholas Piggin2-10/+10
The copy buffer is implemented as a real address in the nest which is translated from EA by copy, and used for memory access by paste. This requires that it be invalidated by TLB invalidation. TLBIE does invalidate the copy buffer, but TLBIEL does not. Add cp_abort to the tlbiel sequence. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Fixup whitespace and comment formatting] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200916030234.4110379-2-npiggin@gmail.com
2020-09-18powerpc/mm/64s: Fix slb_setup_new_exec() sparse warningMichael Ellerman2-2/+4
Sparse says: symbol slb_setup_new_exec was not declared. Should it be static? No, it should have a declaration in a header, add one. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200916115637.3100484-1-mpe@ellerman.id.au
2020-09-18Merge branch 'topic/irqs-off-activate-mm' into nextMichael Ellerman1-7/+16
Merge Nick's series to add ARCH_WANT_IRQS_OFF_ACTIVATE_MM.
2020-09-16powerpc/64s/radix: Fix mm_cpumask trimming race vs kthread_use_mmNicholas Piggin1-7/+16
Commit 0cef77c7798a7 ("powerpc/64s/radix: flush remote CPUs out of single-threaded mm_cpumask") added a mechanism to trim the mm_cpumask of a process under certain conditions. One of the assumptions is that mm_users would not be incremented via a reference outside the process context with mmget_not_zero() then go on to kthread_use_mm() via that reference. That invariant was broken by io_uring code (see previous sparc64 fix), but I'll point Fixes: to the original powerpc commit because we are changing that assumption going forward, so this will make backports match up. Fix this by no longer relying on that assumption, but by having each CPU check the mm is not being used, and clearing their own bit from the mask only if it hasn't been switched-to by the time the IPI is processed. This relies on commit 38cf307c1f20 ("mm: fix kthread_use_mm() vs TLB invalidate") and ARCH_WANT_IRQS_OFF_ACTIVATE_MM to disable irqs over mm switch sequences. Fixes: 0cef77c7798a7 ("powerpc/64s/radix: flush remote CPUs out of single-threaded mm_cpumask") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Michael Ellerman <mpe@ellerman.id.au> Depends-on: 38cf307c1f20 ("mm: fix kthread_use_mm() vs TLB invalidate") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200914045219.3736466-5-npiggin@gmail.com
2020-09-15powerepc/book3s64/hash: Align start/end address correctly with bolt mappingAneesh Kumar K.V2-3/+10
This ensures we don't do a partial mapping of memory. With nvdimm, when creating namespaces with size not aligned to 16MB, the kernel ends up partially mapping the pages. This can result in kernel adding multiple hash page table entries for the same range. A new namespace will result in create_section_mapping() with start and end overlapping an already existing bolted hash page table entry. commit: 6acd7d5ef264 ("libnvdimm/namespace: Enforce memremap_compat_align()") made sure that we always create namespaces aligned to 16MB. But we can do better by avoiding mapping pages that are not aligned. This helps to catch access to these partially mapped pages early. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200907072539.67310-1-aneesh.kumar@linux.ibm.com
2020-09-15powerpc/mm/book3s: Split radix and hash MAX_PHYSMEM limitAneesh Kumar K.V1-2/+2
MAX_PHYSMEM #define is used along with sparsemem to determine the SECTION_SHIFT value. Powerpc also uses the same value to limit the max memory enabled on the system. With 4K PAGE_SIZE and hash translation mode, we want to limit the max memory enabled to 64TB due to page table size restrictions. However, with radix translation, we don't have these restrictions. Hence split the radix and hash MA_PHYSMEM limit and use different limit for each of them. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200608070904.387440-4-aneesh.kumar@linux.ibm.com
2020-08-28powerpc/book3s64/radix: Fix boot failure with large amount of guest memoryAneesh Kumar K.V1-15/+0
If the hypervisor doesn't support hugepages, the kernel ends up allocating a large number of page table pages. The early page table allocation was wrongly setting the max memblock limit to ppc64_rma_size with radix translation which resulted in boot failure as shown below. Kernel panic - not syncing: early_alloc_pgtable: Failed to allocate 16777216 bytes align=0x1000000 nid=-1 from=0x0000000000000000 max_addr=0xffffffffffffffff CPU: 0 PID: 0 Comm: swapper Not tainted 5.8.0-24.9-default+ #2 Call Trace: [c0000000016f3d00] [c0000000007c6470] dump_stack+0xc4/0x114 (unreliable) [c0000000016f3d40] [c00000000014c78c] panic+0x164/0x418 [c0000000016f3dd0] [c000000000098890] early_alloc_pgtable+0xe0/0xec [c0000000016f3e60] [c0000000010a5440] radix__early_init_mmu+0x360/0x4b4 [c0000000016f3ef0] [c000000001099bac] early_init_mmu+0x1c/0x3c [c0000000016f3f10] [c00000000109a320] early_setup+0x134/0x170 This was because the kernel was checking for the radix feature before we enable the feature via mmu_features. This resulted in the kernel using hash restrictions on radix. Rework the early init code such that the kernel boot with memblock restrictions as imposed by hash. At that point, the kernel still hasn't finalized the translation the kernel will end up using. We have three different ways of detecting radix. 1. dt_cpu_ftrs_scan -> used only in case of PowerNV 2. ibm,pa-features -> Used when we don't use cpu_dt_ftr_scan 3. CAS -> Where we negotiate with hypervisor about the supported translation. We look at 1 or 2 early in the boot and after that, we look at the CAS vector to finalize the translation the kernel will use. We also support a kernel command line option (disable_radix) to switch to hash. Update the memblock limit after mmu_early_init_devtree() if the kernel is going to use radix translation. This forces some of the memblock allocations we do before mmu_early_init_devtree() to be within the RMA limit. Fixes: 2bfd65e45e87 ("powerpc/mm/radix: Add radix callbacks for early init routines") Reported-by: Shirisha Ganta <shiganta@in.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reviewed-by: Hari Bathini <hbathini@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200828100852.426575-1-aneesh.kumar@linux.ibm.com
2020-08-24Revert "powerpc/64s: Remove PROT_SAO support"Shawn Anastasio1-0/+2
This reverts commit 5c9fa16e8abd342ce04dc830c1ebb2a03abf6c05. Since PROT_SAO can still be useful for certain classes of software, reintroduce it. Concerns about guest migration for LPARs using SAO will be addressed next. Signed-off-by: Shawn Anastasio <shawn@anastas.io> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200821185558.35561-2-shawn@anastas.io
2020-08-17powerpc/pkeys: Fix build error with PPC_MEM_KEYS disabledAneesh Kumar K.V1-1/+3
IS_ENABLED() instead of #ifdef still requires variable declaration. In this specific case, default_uamor is declared in asm/pkeys.h which is only included if PPC_MEM_KEYS is enabled. arch/powerpc/mm/book3s64/hash_utils.c: In function ‘hash__early_init_mmu_secondary’: arch/powerpc/mm/book3s64/hash_utils.c:1119:21: error: ‘default_uamor’ undeclared (first use in this function) 1119 | mtspr(SPRN_UAMOR, default_uamor); | ^~~~~~~~~~~~~ Fixes: 6553fb799f60 ("powerpc/pkeys: Fix boot failures with Nemo board (A-EON AmigaOne X1000)") Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200817103301.158836-1-aneesh.kumar@linux.ibm.com
2020-08-10powerpc/pkeys: Fix boot failures with Nemo board (A-EON AmigaOne X1000)Aneesh Kumar K.V2-9/+8
On p6 and before we should avoid updating UAMOR SPRN. This resulted in boot failure on Nemo board. Fixes: 269e829f48a0 ("powerpc/book3s64/pkey: Disable pkey on POWER6 and before") Reported-by: Christian Zigotzky <chzigotzky@xenosoft.de> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200810102623.685083-1-aneesh.kumar@linux.ibm.com
2020-08-07Merge branch 'akpm' (patches from Andrew)Linus Torvalds4-4/+0
Merge misc updates from Andrew Morton: - a few MM hotfixes - kthread, tools, scripts, ntfs and ocfs2 - some of MM Subsystems affected by this patch series: kthread, tools, scripts, ntfs, ocfs2 and mm (hofixes, pagealloc, slab-generic, slab, slub, kcsan, debug, pagecache, gup, swap, shmem, memcg, pagemap, mremap, mincore, sparsemem, vmalloc, kasan, pagealloc, hugetlb and vmscan). * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (162 commits) mm: vmscan: consistent update to pgrefill mm/vmscan.c: fix typo khugepaged: khugepaged_test_exit() check mmget_still_valid() khugepaged: retract_page_tables() remember to test exit khugepaged: collapse_pte_mapped_thp() protect the pmd lock khugepaged: collapse_pte_mapped_thp() flush the right range mm/hugetlb: fix calculation of adjust_range_if_pmd_sharing_possible mm: thp: replace HTTP links with HTTPS ones mm/page_alloc: fix memalloc_nocma_{save/restore} APIs mm/page_alloc.c: skip setting nodemask when we are in interrupt mm/page_alloc: fallbacks at most has 3 elements mm/page_alloc: silence a KASAN false positive mm/page_alloc.c: remove unnecessary end_bitidx for [set|get]_pfnblock_flags_mask() mm/page_alloc.c: simplify pageblock bitmap access mm/page_alloc.c: extract the common part in pfn_to_bitidx() mm/page_alloc.c: replace the definition of NR_MIGRATETYPE_BITS with PB_migratetype_bits mm/shuffle: remove dynamic reconfiguration mm/memory_hotplug: document why shuffle_zone() is relevant mm/page_alloc: remove nr_free_pagecache_pages() mm: remove vm_total_pages ...
2020-08-07mm: remove unneeded includes of <asm/pgalloc.h>Mike Rapoport4-4/+0
Patch series "mm: cleanup usage of <asm/pgalloc.h>" Most architectures have very similar versions of pXd_alloc_one() and pXd_free_one() for intermediate levels of page table. These patches add generic versions of these functions in <asm-generic/pgalloc.h> and enable use of the generic functions where appropriate. In addition, functions declared and defined in <asm/pgalloc.h> headers are used mostly by core mm and early mm initialization in arch and there is no actual reason to have the <asm/pgalloc.h> included all over the place. The first patch in this series removes unneeded includes of <asm/pgalloc.h> In the end it didn't work out as neatly as I hoped and moving pXd_alloc_track() definitions to <asm-generic/pgalloc.h> would require unnecessary changes to arches that have custom page table allocations, so I've decided to move lib/ioremap.c to mm/ and make pgalloc-track.h local to mm/. This patch (of 8): In most cases <asm/pgalloc.h> header is required only for allocations of page table memory. Most of the .c files that include that header do not use symbols declared in <asm/pgalloc.h> and do not require that header. As for the other header files that used to include <asm/pgalloc.h>, it is possible to move that include into the .c file that actually uses symbols from <asm/pgalloc.h> and drop the include from the header file. The process was somewhat automated using sed -i -E '/[<"]asm\/pgalloc\.h/d' \ $(grep -L -w -f /tmp/xx \ $(git grep -E -l '[<"]asm/pgalloc\.h')) where /tmp/xx contains all the symbols defined in arch/*/include/asm/pgalloc.h. [rppt@linux.ibm.com: fix powerpc warning] Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Pekka Enberg <penberg@kernel.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k] Cc: Abdul Haleem <abdhalee@linux.vnet.ibm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Joerg Roedel <joro@8bytes.org> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com> Cc: Stafford Horne <shorne@gmail.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Joerg Roedel <jroedel@suse.de> Cc: Matthew Wilcox <willy@infradead.org> Link: http://lkml.kernel.org/r/20200627143453.31835-1-rppt@kernel.org Link: http://lkml.kernel.org/r/20200627143453.31835-2-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-07Merge tag 'powerpc-5.9-1' of ↵Linus Torvalds5-237/+397
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: - Add support for (optionally) using queued spinlocks & rwlocks. - Support for a new faster system call ABI using the scv instruction on Power9 or later. - Drop support for the PROT_SAO mmap/mprotect flag as it will be unsupported on Power10 and future processors, leaving us with no way to implement the functionality it requests. This risks breaking userspace, though we believe it is unused in practice. - A bug fix for, and then the removal of, our custom stack expansion checking. We now allow stack expansion up to the rlimit, like other architectures. - Remove the remnants of our (previously disabled) topology update code, which tried to react to NUMA layout changes on virtualised systems, but was prone to crashes and other problems. - Add PMU support for Power10 CPUs. - A change to our signal trampoline so that we don't unbalance the link stack (branch return predictor) in the signal delivery path. - Lots of other cleanups, refactorings, smaller features and so on as usual. Thanks to: Abhishek Goel, Alastair D'Silva, Alexander A. Klimov, Alexey Kardashevskiy, Alistair Popple, Andrew Donnellan, Aneesh Kumar K.V, Anju T Sudhakar, Anton Blanchard, Arnd Bergmann, Athira Rajeev, Balamuruhan S, Bharata B Rao, Bill Wendling, Bin Meng, Cédric Le Goater, Chris Packham, Christophe Leroy, Christoph Hellwig, Daniel Axtens, Dan Williams, David Lamparter, Desnes A. Nunes do Rosario, Erhard F., Finn Thain, Frederic Barrat, Ganesh Goudar, Gautham R. Shenoy, Geoff Levand, Greg Kurz, Gustavo A. R. Silva, Hari Bathini, Harish, Imre Kaloz, Joel Stanley, Joe Perches, John Crispin, Jordan Niethe, Kajol Jain, Kamalesh Babulal, Kees Cook, Laurent Dufour, Leonardo Bras, Li RongQing, Madhavan Srinivasan, Mahesh Salgaonkar, Mark Cave-Ayland, Michal Suchanek, Milton Miller, Mimi Zohar, Murilo Opsfelder Araujo, Nathan Chancellor, Nathan Lynch, Naveen N. Rao, Nayna Jain, Nicholas Piggin, Oliver O'Halloran, Palmer Dabbelt, Pedro Miraglia Franco de Carvalho, Philippe Bergheaud, Pingfan Liu, Pratik Rajesh Sampat, Qian Cai, Qinglang Miao, Randy Dunlap, Ravi Bangoria, Sachin Sant, Sam Bobroff, Sandipan Das, Santosh Sivaraj, Satheesh Rajendran, Shirisha Ganta, Sourabh Jain, Srikar Dronamraju, Stan Johnson, Stephen Rothwell, Thadeu Lima de Souza Cascardo, Thiago Jung Bauermann, Tom Lane, Vaibhav Jain, Vladis Dronov, Wei Yongjun, Wen Xiong, YueHaibing. * tag 'powerpc-5.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (337 commits) selftests/powerpc: Fix pkey syscall redefinitions powerpc: Fix circular dependency between percpu.h and mmu.h powerpc/powernv/sriov: Fix use of uninitialised variable selftests/powerpc: Skip vmx/vsx/tar/etc tests on older CPUs powerpc/40x: Fix assembler warning about r0 powerpc/papr_scm: Add support for fetching nvdimm 'fuel-gauge' metric powerpc/papr_scm: Fetch nvdimm performance stats from PHYP cpuidle: pseries: Fixup exit latency for CEDE(0) cpuidle: pseries: Add function to parse extended CEDE records cpuidle: pseries: Set the latency-hint before entering CEDE selftests/powerpc: Fix online CPU selection powerpc/perf: Consolidate perf_callchain_user_[64|32]() powerpc/pseries/hotplug-cpu: Remove double free in error path powerpc/pseries/mobility: Add pr_debug() for device tree changes powerpc/pseries/mobility: Set pr_fmt() powerpc/cacheinfo: Warn if cache object chain becomes unordered powerpc/cacheinfo: Improve diagnostics about malformed cache lists powerpc/cacheinfo: Use name@unit instead of full DT path in debug messages powerpc/cacheinfo: Set pr_fmt() powerpc: fix function annotations to avoid section mismatch warnings with gcc-10 ...
2020-07-30powerpc: fix function annotations to avoid section mismatch warnings with gcc-10Vladis Dronov1-2/+2
Certain warnings are emitted for powerpc code when building with a gcc-10 toolset: WARNING: modpost: vmlinux.o(.text.unlikely+0x377c): Section mismatch in reference from the function remove_pmd_table() to the function .meminit.text:split_kernel_mapping() The function remove_pmd_table() references the function __meminit split_kernel_mapping(). This is often because remove_pmd_table lacks a __meminit annotation or the annotation of split_kernel_mapping is wrong. Add the appropriate __init and __meminit annotations to make modpost not complain. In all the cases there are just a single callsite from another __init or __meminit function: __meminit remove_pagetable() -> remove_pud_table() -> remove_pmd_table() __init prom_init() -> setup_secure_guest() __init xive_spapr_init() -> xive_spapr_disabled() Signed-off-by: Vladis Dronov <vdronov@redhat.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200729133741.62789-1-vdronov@redhat.com
2020-07-29powerpc/mm: Limit resize_hpt_for_hotplug() call to hash guests onlyBharata B Rao1-1/+7
During memory hotplug and unplug, resize_hpt_for_hotplug() gets called for both hash and radix guests but it should be called only for hash guests. Though the call does nothing in the radix guest case, it is cleaner to push this call into hash specific memory hotplug routines. Reported-by: Nathan Lynch <nathanl@linux.ibm.com> Signed-off-by: Bharata B Rao <bharata@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200727095704.1432916-1-bharata@linux.ibm.com
2020-07-27powerpc/64s/hash: Fix hash_preload running with interrupts enabledNicholas Piggin1-0/+25
Commit 2f92447f9f96 ("powerpc/book3s64/hash: Use the pte_t address from the caller") removed the local_irq_disable from hash_preload, but it was required for more than just the page table walk: the hash pte busy bit is effectively a lock which may be taken in interrupt context, and the local update flag test must not be preempted before it's used. This solves apparent lockups with perf interrupting __hash_page_64K. If get_perf_callchain then also takes a hash fault on the same page while it is already locked, it will loop forever taking hash faults, which looks like this: cpu 0x49e: Vector: 100 (System Reset) at [c00000001a4f7d70] pc: c000000000072dc8: hash_page_mm+0x8/0x800 lr: c00000000000c5a4: do_hash_page+0x24/0x38 sp: c0002ac1cc69ac70 msr: 8000000000081033 current = 0xc0002ac1cc602e00 paca = 0xc00000001de1f280 irqmask: 0x03 irq_happened: 0x01 pid = 20118, comm = pread2_processe Linux version 5.8.0-rc6-00345-g1fad14f18bc6 49e:mon> t [c0002ac1cc69ac70] c00000000000c5a4 do_hash_page+0x24/0x38 (unreliable) --- Exception: 300 (Data Access) at c00000000008fa60 __copy_tofrom_user_power7+0x20c/0x7ac [link register ] c000000000335d10 copy_from_user_nofault+0xf0/0x150 [c0002ac1cc69af70] c00032bf9fa3c880 (unreliable) [c0002ac1cc69afa0] c000000000109df0 read_user_stack_64+0x70/0xf0 [c0002ac1cc69afd0] c000000000109fcc perf_callchain_user_64+0x15c/0x410 [c0002ac1cc69b060] c000000000109c00 perf_callchain_user+0x20/0x40 [c0002ac1cc69b080] c00000000031c6cc get_perf_callchain+0x25c/0x360 [c0002ac1cc69b120] c000000000316b50 perf_callchain+0x70/0xa0 [c0002ac1cc69b140] c000000000316ddc perf_prepare_sample+0x25c/0x790 [c0002ac1cc69b1a0] c000000000317350 perf_event_output_forward+0x40/0xb0 [c0002ac1cc69b220] c000000000306138 __perf_event_overflow+0x88/0x1a0 [c0002ac1cc69b270] c00000000010cf70 record_and_restart+0x230/0x750 [c0002ac1cc69b620] c00000000010d69c perf_event_interrupt+0x20c/0x510 [c0002ac1cc69b730] c000000000027d9c performance_monitor_exception+0x4c/0x60 [c0002ac1cc69b750] c00000000000b2f8 performance_monitor_common_virt+0x1b8/0x1c0 --- Exception: f00 (Performance Monitor) at c0000000000cb5b0 pSeries_lpar_hpte_insert+0x0/0x160 [link register ] c0000000000846f0 __hash_page_64K+0x210/0x540 [c0002ac1cc69ba50] 0000000000000000 (unreliable) [c0002ac1cc69bb00] c000000000073ae0 update_mmu_cache+0x390/0x3a0 [c0002ac1cc69bb70] c00000000037f024 wp_page_copy+0x364/0xce0 [c0002ac1cc69bc20] c00000000038272c do_wp_page+0xdc/0xa60 [c0002ac1cc69bc70] c0000000003857bc handle_mm_fault+0xb9c/0x1b60 [c0002ac1cc69bd50] c00000000006c434 __do_page_fault+0x314/0xc90 [c0002ac1cc69be20] c00000000000c5c8 handle_page_fault+0x10/0x2c --- Exception: 300 (Data Access) at 00007fff8c861fe8 SP (7ffff6b19660) is in userspace Fixes: 2f92447f9f96 ("powerpc/book3s64/hash: Use the pte_t address from the caller") Reported-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com> Reported-by: Anton Blanchard <anton@ozlabs.org> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200727060947.10060-1-npiggin@gmail.com
2020-07-26powerpc/book3s64/pkey: Disable pkey on POWER6 and beforeAneesh Kumar K.V1-0/+6
POWER6 only supports AMR update via privileged mode (MSR[PR] = 0, SPRN_AMR=29) The PR=1 (userspace) alias for that SPR (SPRN_AMR=13) was only supported from POWER7. Since we don't allow userspace modifying of AMR value we should disable pkey support on P6 and before. The hypervisor will still report pkey support via "ibm,processor-storage-keys". Hence also check for P7 CPU_FTR bit to decide on pkey support. Fixes: f491fe3fb41e ("powerpc/book3s64/pkeys: Simplify the key initialization") Reported-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200726132517.399076-1-aneesh.kumar@linux.ibm.com
2020-07-23powerpc/mm/hash64: Remove comment that is no longer validSantosh Sivaraj1-4/+0
hash_low_64.S was removed in commit a43c0eb8364c ("powerpc/mm: Convert 4k insert from asm to C") and flush_hash_page() is no longer called from any assembly routine. Signed-off-by: Santosh Sivaraj <santosh@fossix.org> [mpe: Tweak comment wording] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200721091915.205006-1-santosh@fossix.org
2020-07-21powerpc/64s: Remove PROT_SAO supportNicholas Piggin1-2/+0
ISA v3.1 does not support the SAO storage control attribute required to implement PROT_SAO. PROT_SAO was used by specialised system software (Lx86) that has been discontinued for about 7 years, and is not thought to be used elsewhere, so removal should not cause problems. We rather remove it than keep support for older processors, because live migrating guest partitions to newer processors may not be possible if SAO is in use (or worse allowed with silent races). - PROT_SAO stays in the uapi header so code using it would still build. - arch_validate_prot() is removed, the generic version rejects PROT_SAO so applications would get a failure at mmap() time. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Drop KVM change for the time being] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200703011958.1166620-3-npiggin@gmail.com
2020-07-21powerpc/book3s64/pkeys: Remove is_pkey_enabled()Aneesh Kumar K.V1-20/+11
There is only one caller to this function and the function is wrongly named. Avoid further confusion w.r.t name and open code this at the only call site. Also remove read_uamor(). There are no users for the same after this. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200709032946.881753-24-aneesh.kumar@linux.ibm.com
2020-07-20powerpc/book3s64/kuap: Move UAMOR setup to key init functionAneesh Kumar K.V3-17/+20
UAMOR values are not application-specific. The kernel initializes its value based on different reserved keys. Remove the thread-specific UAMOR value and don't switch the UAMOR on context switch. Move UAMOR initialization to key initialization code and remove thread_struct.uamor because it is not used anymore. Before commit: 4a4a5e5d2aad ("powerpc/pkeys: key allocation/deallocation must not change pkey registers") we used to update uamor based on key allocation and free. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200709032946.881753-20-aneesh.kumar@linux.ibm.com
2020-07-20powerpc/book3s64/keys/kuap: Reset AMR/IAMR values on kexecAneesh Kumar K.V1-0/+3
As we kexec across kernels that use AMR/IAMR for different purposes we need to ensure that new kernels get kexec'd with a reset value of AMR/IAMR. For ex: the new kernel can use key 0 for kernel mapping and the old AMR value prevents access to key 0. This patch also removes reset if IAMR and AMOR in kexec_sequence. Reset of AMOR is not needed and the IAMR reset is partial (it doesn't do the reset on secondary cpus) and is redundant with this patch. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200709032946.881753-19-aneesh.kumar@linux.ibm.com
2020-07-20powerpc/book3s64/keys: Print information during boot.Aneesh Kumar K.V1-0/+1
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200709032946.881753-18-aneesh.kumar@linux.ibm.com
2020-07-20powerpc/book3s64/pkeys: Use MMU_FTR_PKEY instead of pkey_disabled static keyAneesh Kumar K.V1-10/+7
Instead of pkey_disabled static key use mmu feature MMU_FTR_PKEY. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200709032946.881753-17-aneesh.kumar@linux.ibm.com
2020-07-20powerpc/book3s64/pkeys: Use pkey_execute_disable_supportedAneesh Kumar K.V1-3/+3
Use pkey_execute_disable_supported to check for execute key support instead of pkey_disabled. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200709032946.881753-16-aneesh.kumar@linux.ibm.com
2020-07-20powerpc/book3s64/kuep: Add MMU_FTR_KUEPAneesh Kumar K.V1-1/+3
This will be used to enable/disable Kernel Userspace Execution Prevention (KUEP). Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200709032946.881753-15-aneesh.kumar@linux.ibm.com
2020-07-20powerpc/book3s64/pkeys: Add MMU_FTR_PKEYAneesh Kumar K.V1-22/+30
Parse storage keys related device tree entry in early_init_devtree and enable MMU feature MMU_FTR_PKEY if pkeys are supported. MMU feature is used instead of CPU feature because this enables us to group MMU_FTR_KUAP and MMU_FTR_PKEY in asm feature fixup code. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200709032946.881753-14-aneesh.kumar@linux.ibm.com
2020-07-20powerpc/book3s64/pkeys: Mark all the pkeys above max pkey as reservedAneesh Kumar K.V1-2/+3
The hypervisor can return less than max allowed pkey (for ex: 31) instead of 32. We should mark all the pkeys above max allowed as reserved so that we avoid the allocation of the wrong pkey(for ex: key 31 in the above case) by userspace. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200709032946.881753-13-aneesh.kumar@linux.ibm.com
2020-07-20powerpc/book3s64/pkeys: Make initial_allocation_mask staticAneesh Kumar K.V1-2/+5
initial_allocation_mask is not used outside this file. Also mark reserved_allocation_mask and initial_allocation_mask __ro_after_init; Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200709032946.881753-12-aneesh.kumar@linux.ibm.com
2020-07-20powerpc/book3s64/pkeys: Convert pkey_total to num_pkeyAneesh Kumar K.V1-7/+7
num_pkey now represents max number of keys supported such that we return to userspace 0 - num_pkey - 1. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200709032946.881753-11-aneesh.kumar@linux.ibm.com
2020-07-20powerpc/book3s64/pkeys: Simplify pkey disable branchAneesh Kumar K.V1-4/+3
Make the default value FALSE (pkey enabled) and set to TRUE when we find the total number of keys supported to be zero. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200709032946.881753-10-aneesh.kumar@linux.ibm.com
2020-07-20powerpc/book3s64/pkeys: Prevent key 1 modification from userspace.Aneesh Kumar K.V1-0/+1
Key 1 is marked reserved by ISA. Setup uamor to prevent userspace modification of the same. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200709032946.881753-8-aneesh.kumar@linux.ibm.com
2020-07-20powerpc/book3s64/pkeys: Simplify the key initializationAneesh Kumar K.V1-83/+116
Add documentation explaining the execute_only_key. The reservation and initialization mask details are also explained in this patch. No functional change in this patch. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200709032946.881753-7-aneesh.kumar@linux.ibm.com
2020-07-20powerpc/book3s64/pkeys: Explain key 1 reservation detailsAneesh Kumar K.V1-1/+4
This explains the details w.r.t key 1. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200709032946.881753-6-aneesh.kumar@linux.ibm.com
2020-07-20powerpc/book3s64/pkeys: Use PVR check instead of cpu featureAneesh Kumar K.V1-6/+10
We are wrongly using CPU_FTRS_POWER8 to check for P8 support. Instead, we should use PVR value. Now considering we are using CPU_FTRS_POWER8, that implies we returned true for P9 with older firmware. Keep the same behavior by checking for P9 PVR value. Fixes: cf43d3b26452 ("powerpc: Enable pkey subsystem") Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200709032946.881753-2-aneesh.kumar@linux.ibm.com
2020-07-20powerpc/mm/radix: Create separate mappings for hot-plugged memoryAneesh Kumar K.V1-11/+80
To enable memory unplug without splitting kernel page table mapping, we force the max mapping size to the LMB size. LMB size is the unit in which hypervisor will do memory add/remove operation. Pseries systems supports max LMB size of 256MB. Hence on pseries, we now end up mapping memory with 2M page size instead of 1G. To improve that we want hypervisor to hint the kernel about the hotplug memory range. That was added that as part of commit b6eca183e23e ("powerpc/kernel: Enables memory hot-remove after reboot on pseries guests") But PowerVM doesn't provide that hint yet. Once we get PowerVM updated, we can then force the 2M mapping only to hot-pluggable memory region using memblock_is_hotpluggable(). Till then let's depend on LMB size for finding the mapping page size for linear range. With this change KVM guest will also be doing linear mapping with 2M page size. The actual TLB benefit of mapping guest page table entries with hugepage size can only be materialized if the partition scoped entries are also using the same or higher page size. A guest using 1G hugetlbfs backing guest memory can have a performance impact with the above change. Signed-off-by: Bharata B Rao <bharata@linux.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> [mpe: Fold in fix from Aneesh spotted by lkp@intel.com] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200709131925.922266-5-aneesh.kumar@linux.ibm.com
2020-07-20powerpc/mm/radix: Remove split_kernel_mapping()Bharata B Rao1-76/+19
We split the page table mapping on memory unplug if the linear range was mapped with huge page mapping (for ex: 1G) The page table splitting code has a few issues: 1. Recursive locking -------------------- Memory unplug path takes cpu_hotplug_lock and calls stop_machine() for splitting the mappings. However stop_machine() takes cpu_hotplug_lock again causing deadlock. 2. BUG: sleeping function called from in_atomic() context --------------------------------------------------------- Memory unplug path (remove_pagetable) takes init_mm.page_table_lock spinlock and later calls stop_machine() which does wait_for_completion() 3. Bad unlock unbalance ----------------------- Memory unplug path takes init_mm.page_table_lock spinlock and calls stop_machine(). The stop_machine thread function runs in a different thread context (migration thread) which tries to release and reaquire ptl. Releasing ptl from a different thread than which acquired it causes bad unlock unbalance. These problems can be avoided if we avoid mapping hot-plugged memory with 1G mapping, thereby removing the need for splitting them during unplug. The kernel always make sure the minimum unplug request is SUBSECTION_SIZE for device memory and SECTION_SIZE for regular memory. In preparation for such a change remove page table splitting support. This essentially is a revert of commit 4dd5f8a99e791 ("powerpc/mm/radix: Split linear mapping on hot-unplug") Signed-off-by: Bharata B Rao <bharata@linux.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200709131925.922266-4-aneesh.kumar@linux.ibm.com
2020-07-20powerpc/mm/radix: Free PUD table when freeing pagetableBharata B Rao1-0/+16
remove_pagetable() isn't freeing PUD table. This causes memory leak during memory unplug. Fix this. Fixes: 4b5d62ca17a1 ("powerpc/mm: add radix__remove_section_mapping()") Signed-off-by: Bharata B Rao <bharata@linux.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200709131925.922266-3-aneesh.kumar@linux.ibm.com
2020-07-20powerpc/mm/radix: Fix PTE/PMD fragment count for early page table mappingsAneesh Kumar K.V2-5/+15
We can hit the following BUG_ON during memory unplug: kernel BUG at arch/powerpc/mm/book3s64/pgtable.c:342! Oops: Exception in kernel mode, sig: 5 [#1] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries NIP [c000000000093308] pmd_fragment_free+0x48/0xc0 LR [c00000000147bfec] remove_pagetable+0x578/0x60c Call Trace: 0xc000008050000000 (unreliable) remove_pagetable+0x384/0x60c radix__remove_section_mapping+0x18/0x2c remove_section_mapping+0x1c/0x3c arch_remove_memory+0x11c/0x180 try_remove_memory+0x120/0x1b0 __remove_memory+0x20/0x40 dlpar_remove_lmb+0xc0/0x114 dlpar_memory+0x8b0/0xb20 handle_dlpar_errorlog+0xc0/0x190 pseries_hp_work_fn+0x2c/0x60 process_one_work+0x30c/0x810 worker_thread+0x98/0x540 kthread+0x1c4/0x1d0 ret_from_kernel_thread+0x5c/0x74 This occurs when unplug is attempted for such memory which has been mapped using memblock pages as part of early kernel page table setup. We wouldn't have initialized the PMD or PTE fragment count for those PMD or PTE pages. This can be fixed by allocating memory in PAGE_SIZE granularity during early page table allocation. This makes sure a specific page is not shared for another memblock allocation and we can free them correctly on removing page-table pages. Since we now do PAGE_SIZE allocations for both PUD table and PMD table (Note that PTE table allocation is already of PAGE_SIZE), we end up allocating more memory for the same amount of system RAM. Here is a comparision of how much more we need for a 64T and 2G system after this patch: 1. 64T system ------------- 64T RAM would need 64G for vmemmap with struct page size being 64B. 128 PUD tables for 64T memory (1G mappings) 1 PUD table and 64 PMD tables for 64G vmemmap (2M mappings) With default PUD[PMD]_TABLE_SIZE(4K), (128+1+64)*4K=772K With PAGE_SIZE(64K) table allocations, (128+1+64)*64K=12352K 2. 2G system ------------ 2G RAM would need 2M for vmemmap with struct page size being 64B. 1 PUD table for 2G memory (1G mapping) 1 PUD table and 1 PMD table for 2M vmemmap (2M mappings) With default PUD[PMD]_TABLE_SIZE(4K), (1+1+1)*4K=12K With new PAGE_SIZE(64K) table allocations, (1+1+1)*64K=192K Signed-off-by: Bharata B Rao <bharata@linux.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200709131925.922266-2-aneesh.kumar@linux.ibm.com