summaryrefslogtreecommitdiff
path: root/arch/powerpc/mm
AgeCommit message (Collapse)Author
2021-02-09powerpc/64: context tracking move to interrupt wrappersNicholas Piggin
This moves exception_enter/exit calls to wrapper functions for synchronous interrupts. More interrupt handlers are covered by this than previously. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210130130852.2952424-33-npiggin@gmail.com
2021-02-09powerpc/64s/hash: improve context tracking of hash faultsNicholas Piggin
This moves the 64s/hash context tracking from hash_page_mm() to __do_hash_fault(), so it's no longer called by OCXL / SPU accelerators, which was certainly the wrong thing to be doing, because those callers are not low level interrupt handlers, so should have entered a kernel context tracking already. Then remain in kernel context for the duration of the fault, rather than enter/exit for the hash fault then enter/exit for the page fault, which is pointless. Even still, calling exception_enter/exit in __do_hash_fault seems questionable because that's touching per-cpu variables, tracing, etc., which might have been interrupted by this hash fault or themselves cause hash faults. But maybe I miss something because hash_page_mm very deliberately calls trace_hash_fault too, for example. So for now go with it, it's no worse than before, in this regard. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210130130852.2952424-32-npiggin@gmail.com
2021-02-09powerpc: add interrupt_cond_local_irq_enable helperNicholas Piggin
Simple helper for synchronous interrupt handlers (i.e., process-context) to enable interrupts if it was taken in an interrupts-enabled context. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210130130852.2952424-30-npiggin@gmail.com
2021-02-09powerpc: convert interrupt handlers to use wrappersNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210130130852.2952424-29-npiggin@gmail.com
2021-02-09powerpc/64s: slb comment updateNicholas Piggin
This makes a small improvement to the description of the SLB interrupt environment. Move the memory access restrictions into one paragraph, and the interrupt restrictions into the next rather than mix them. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210130130852.2952424-18-npiggin@gmail.com
2021-02-09powerpc/mm: Remove stale do_page_fault comment referring to SLB faultsNicholas Piggin
SLB faults no longer call do_page_fault, this was removed somewhere between 2.6.0 and 2.6.12. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210130130852.2952424-17-npiggin@gmail.com
2021-02-09powerpc/64s: split do_hash_faultNicholas Piggin
This is required for subsequent interrupt wrapper implementation. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210130130852.2952424-16-npiggin@gmail.com
2021-02-09powerpc/64s: move bad_page_fault handling to CNicholas Piggin
This simplifies code, and it is also useful when introducing interrupt handler wrappers when introducing wrapper functionality that doesn't cope with asm entry code calling into more than one handler function. 32-bit and 64e still have some such cases, which limits some ways they can use interrupt wrappers. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210130130852.2952424-15-npiggin@gmail.com
2021-02-09powerpc: rearrange do_page_fault error case to be inside exception_enterNicholas Piggin
This keeps the context tracking over the entire interrupt handler which helps later with moving context tracking into interrupt wrappers. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210130130852.2952424-14-npiggin@gmail.com
2021-02-09powerpc/64s: add do_bad_page_fault_segv handlerNicholas Piggin
This function acts like an interrupt handler so it needs to follow the standard interrupt handler function signature which will be introduced in a future change. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210130130852.2952424-13-npiggin@gmail.com
2021-02-09powerpc: bad_page_fault get registers from regsNicholas Piggin
Similar to the previous patch this makes interrupt handler function types more regular so they can be wrapped with the next patch. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210130130852.2952424-12-npiggin@gmail.com
2021-02-09powerpc: remove arguments from fault handler functionsNicholas Piggin
Make mm fault handlers all just take the pt_regs * argument and load DAR/DSISR from that. Make those that return a value return long. This is done to make the function signatures match other handlers, which will help with a future patch to add wrappers. Explicit arguments could be added for performance but that would require more wrapper macro variants. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210130130852.2952424-7-npiggin@gmail.com
2021-02-09powerpc/64s: move the hash fault handling logic to CNicholas Piggin
The fault handling still has some complex logic particularly around hash table handling, in asm. Implement most of this in C. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210130130852.2952424-6-npiggin@gmail.com
2021-02-06powerpc/kuap: Allow kernel thread to access userspace after kthread_use_mmAneesh Kumar K.V
This fix the bad fault reported by KUAP when io_wqe_worker access userspace. Bug: Read fault blocked by KUAP! WARNING: CPU: 1 PID: 101841 at arch/powerpc/mm/fault.c:229 __do_page_fault+0x6b4/0xcd0 NIP [c00000000009e7e4] __do_page_fault+0x6b4/0xcd0 LR [c00000000009e7e0] __do_page_fault+0x6b0/0xcd0 .......... Call Trace: [c000000016367330] [c00000000009e7e0] __do_page_fault+0x6b0/0xcd0 (unreliable) [c0000000163673e0] [c00000000009ee3c] do_page_fault+0x3c/0x120 [c000000016367430] [c00000000000c848] handle_page_fault+0x10/0x2c --- interrupt: 300 at iov_iter_fault_in_readable+0x148/0x6f0 .......... NIP [c0000000008e8228] iov_iter_fault_in_readable+0x148/0x6f0 LR [c0000000008e834c] iov_iter_fault_in_readable+0x26c/0x6f0 interrupt: 300 [c0000000163677e0] [c0000000007154a0] iomap_write_actor+0xc0/0x280 [c000000016367880] [c00000000070fc94] iomap_apply+0x1c4/0x780 [c000000016367990] [c000000000710330] iomap_file_buffered_write+0xa0/0x120 [c0000000163679e0] [c00800000040791c] xfs_file_buffered_aio_write+0x314/0x5e0 [xfs] [c000000016367a90] [c0000000006d74bc] io_write+0x10c/0x460 [c000000016367bb0] [c0000000006d80e4] io_issue_sqe+0x8d4/0x1200 [c000000016367c70] [c0000000006d8ad0] io_wq_submit_work+0xc0/0x250 [c000000016367cb0] [c0000000006e2578] io_worker_handle_work+0x498/0x800 [c000000016367d40] [c0000000006e2cdc] io_wqe_worker+0x3fc/0x4f0 [c000000016367da0] [c0000000001cb0a4] kthread+0x1c4/0x1d0 [c000000016367e10] [c00000000000dbf0] ret_from_kernel_thread+0x5c/0x6c The kernel consider thread AMR value for kernel thread to be AMR_KUAP_BLOCKED. Hence access to userspace is denied. This of course not correct and we should allow userspace access after kthread_use_mm(). To be precise, kthread_use_mm() should inherit the AMR value of the operating address space. But, the AMR value is thread-specific and we inherit the address space and not thread access restrictions. Because of this ignore AMR value when accessing userspace via kernel thread. current_thread_amr/iamr() are updated, because we use them in the below stack. .... [ 530.710838] CPU: 13 PID: 5587 Comm: io_wqe_worker-0 Tainted: G D 5.11.0-rc6+ #3 .... NIP [c0000000000aa0c8] pkey_access_permitted+0x28/0x90 LR [c0000000004b9278] gup_pte_range+0x188/0x420 --- interrupt: 700 [c00000001c4ef3f0] [0000000000000000] 0x0 (unreliable) [c00000001c4ef490] [c0000000004bd39c] gup_pgd_range+0x3ac/0xa20 [c00000001c4ef5a0] [c0000000004bdd44] internal_get_user_pages_fast+0x334/0x410 [c00000001c4ef620] [c000000000852028] iov_iter_get_pages+0xf8/0x5c0 [c00000001c4ef6a0] [c0000000007da44c] bio_iov_iter_get_pages+0xec/0x700 [c00000001c4ef770] [c0000000006a325c] iomap_dio_bio_actor+0x2ac/0x4f0 [c00000001c4ef810] [c00000000069cd94] iomap_apply+0x2b4/0x740 [c00000001c4ef920] [c0000000006a38b8] __iomap_dio_rw+0x238/0x5c0 [c00000001c4ef9d0] [c0000000006a3c60] iomap_dio_rw+0x20/0x80 [c00000001c4ef9f0] [c008000001927a30] xfs_file_dio_aio_write+0x1f8/0x650 [xfs] [c00000001c4efa60] [c0080000019284dc] xfs_file_write_iter+0xc4/0x130 [xfs] [c00000001c4efa90] [c000000000669984] io_write+0x104/0x4b0 [c00000001c4efbb0] [c00000000066cea4] io_issue_sqe+0x3d4/0xf50 [c00000001c4efc60] [c000000000670200] io_wq_submit_work+0xb0/0x2f0 [c00000001c4efcb0] [c000000000674268] io_worker_handle_work+0x248/0x4a0 [c00000001c4efd30] [c0000000006746e8] io_wqe_worker+0x228/0x2a0 [c00000001c4efda0] [c00000000019d994] kthread+0x1b4/0x1c0 Fixes: 48a8ab4eeb82 ("powerpc/book3s64/pkeys: Don't update SPRN_AMR when in kernel mode.") Reported-by: Zorro Lang <zlang@redhat.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/20210206025634.521979-1-aneesh.kumar@linux.ibm.com
2021-01-31powerpc/32s: Only build hash code when CONFIG_PPC_BOOK3S_604 is selectedChristophe Leroy
It is now possible to only build book3s/32 kernel for CPUs without hash table. Opt out hash related code when CONFIG_PPC_BOOK3S_604 is not selected. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/62df436454ef06e104cc334a0859a2878d7888d5.1608274548.git.christophe.leroy@csgroup.eu
2021-01-31powerpc/mm/book3s64/iommu: fix some RCU-list locksQian Cai
It is safe to traverse mm->context.iommu_group_mem_list with either mem_list_mutex or the RCU read lock held. Silence a few RCU-list false positive warnings and fix a few missing RCU read locks. arch/powerpc/mm/book3s64/iommu_api.c:330 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 2 locks held by qemu-kvm/4305: #0: c000000bc3fe4d68 (&container->lock){+.+.}-{3:3}, at: tce_iommu_ioctl.part.9+0xc7c/0x1870 [vfio_iommu_spapr_tce] #1: c000000001501910 (mem_list_mutex){+.+.}-{3:3}, at: mm_iommu_get+0x50/0x190 ==== arch/powerpc/mm/book3s64/iommu_api.c:132 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 2 locks held by qemu-kvm/4305: #0: c000000bc3fe4d68 (&container->lock){+.+.}-{3:3}, at: tce_iommu_ioctl.part.9+0xc7c/0x1870 [vfio_iommu_spapr_tce] #1: c000000001501910 (mem_list_mutex){+.+.}-{3:3}, at: mm_iommu_do_alloc+0x120/0x5f0 ==== arch/powerpc/mm/book3s64/iommu_api.c:292 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 2 locks held by qemu-kvm/4312: #0: c000000ecafe23c8 (&vcpu->mutex){+.+.}-{3:3}, at: kvm_vcpu_ioctl+0xdc/0x950 [kvm] #1: c000000045e6c468 (&kvm->srcu){....}-{0:0}, at: kvmppc_h_put_tce+0x88/0x340 [kvm] ==== arch/powerpc/mm/book3s64/iommu_api.c:424 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 2 locks held by qemu-kvm/4312: #0: c000000ecafe23c8 (&vcpu->mutex){+.+.}-{3:3}, at: kvm_vcpu_ioctl+0xdc/0x950 [kvm] #1: c000000045e6c468 (&kvm->srcu){....}-{0:0}, at: kvmppc_h_put_tce+0x88/0x340 [kvm] Signed-off-by: Qian Cai <cai@lca.pw> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200510051559.1959-1-cai@lca.pw
2021-01-30powerpc/mm/hugetlb: Make pseries_alloc_bootmem_huge_page() staticCédric Le Goater
pseries_alloc_bootmem_huge_page() is only used locally in alloc_bootmem_huge_page() and does not need to be external. It fixes this W=1 compile error : ../arch/powerpc/mm/hugetlbpage.c:220:12: error: no previous prototype for ‘pseries_alloc_bootmem_huge_page’ [-Werror=missing-prototypes] 220 | int __init pseries_alloc_bootmem_huge_page(struct hstate *hstate) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Signed-off-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210104143206.695198-16-clg@kaod.org
2021-01-30powerpc/mm: Move hpte_insert_repeating() prototypeCédric Le Goater
It fixes this W=1 compile error : ../arch/powerpc/mm/book3s64/hash_utils.c:1867:6: error: no previous prototype for ‘hpte_insert_repeating’ [-Werror=missing-prototypes] 1867 | long hpte_insert_repeating(unsigned long hash, unsigned long vpn, | ^~~~~~~~~~~~~~~~~~~~~ Signed-off-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210104143206.695198-14-clg@kaod.org
2021-01-30powerpc/mm: Include __find_linux_pte() prototypeCédric Le Goater
It fixes this W=1 compile error : ../arch/powerpc/mm/pgtable.c:337:8: error: no previous prototype for ‘__find_linux_pte’ [-Werror=missing-prototypes] 337 | pte_t *__find_linux_pte(pgd_t *pgdir, unsigned long ea, | ^~~~~~~~~~~~~~~~ Signed-off-by: Cédric Le Goater <clg@kaod.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210104143206.695198-2-clg@kaod.org
2020-12-17Merge tag 'powerpc-5.11-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: - Switch to the generic C VDSO, as well as some cleanups of our VDSO setup/handling code. - Support for KUAP (Kernel User Access Prevention) on systems using the hashed page table MMU, using memory protection keys. - Better handling of PowerVM SMT8 systems where all threads of a core do not share an L2, allowing the scheduler to make better scheduling decisions. - Further improvements to our machine check handling. - Show registers when unwinding interrupt frames during stack traces. - Improvements to our pseries (PowerVM) partition migration code. - Several series from Christophe refactoring and cleaning up various parts of the 32-bit code. - Other smaller features, fixes & cleanups. Thanks to: Alan Modra, Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V, Ard Biesheuvel, Athira Rajeev, Balamuruhan S, Bill Wendling, Cédric Le Goater, Christophe Leroy, Christophe Lombard, Colin Ian King, Daniel Axtens, David Hildenbrand, Frederic Barrat, Ganesh Goudar, Gautham R. Shenoy, Geert Uytterhoeven, Giuseppe Sacco, Greg Kurz, Harish, Jan Kratochvil, Jordan Niethe, Kaixu Xia, Laurent Dufour, Leonardo Bras, Madhavan Srinivasan, Mahesh Salgaonkar, Mathieu Desnoyers, Nathan Lynch, Nicholas Piggin, Oleg Nesterov, Oliver O'Halloran, Oscar Salvador, Po-Hsu Lin, Qian Cai, Qinglang Miao, Randy Dunlap, Ravi Bangoria, Sachin Sant, Sandipan Das, Sebastian Andrzej Siewior , Segher Boessenkool, Srikar Dronamraju, Tyrel Datwyler, Uwe Kleine-König, Vincent Stehlé, Youling Tang, and Zhang Xiaoxu. * tag 'powerpc-5.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (304 commits) powerpc/32s: Fix cleanup_cpu_mmu_context() compile bug powerpc: Add config fragment for disabling -Werror powerpc/configs: Add ppc64le_allnoconfig target powerpc/powernv: Rate limit opal-elog read failure message powerpc/pseries/memhotplug: Quieten some DLPAR operations powerpc/ps3: use dma_mapping_error() powerpc: force inlining of csum_partial() to avoid multiple csum_partial() with GCC10 powerpc/perf: Fix Threshold Event Counter Multiplier width for P10 powerpc/mm: Fix hugetlb_free_pmd_range() and hugetlb_free_pud_range() KVM: PPC: Book3S HV: Fix mask size for emulated msgsndp KVM: PPC: fix comparison to bool warning KVM: PPC: Book3S: Assign boolean values to a bool variable powerpc: Inline setup_kup() powerpc/64s: Mark the kuap/kuep functions non __init KVM: PPC: Book3S HV: XIVE: Add a comment regarding VP numbering powerpc/xive: Improve error reporting of OPAL calls powerpc/xive: Simplify xive_do_source_eoi() powerpc/xive: Remove P9 DD1 flag XIVE_IRQ_FLAG_EOI_FW powerpc/xive: Remove P9 DD1 flag XIVE_IRQ_FLAG_MASK_FW powerpc/xive: Remove P9 DD1 flag XIVE_IRQ_FLAG_SHIFT_BUG ...
2020-12-15powerpc/mm: Fix hugetlb_free_pmd_range() and hugetlb_free_pud_range()Christophe Leroy
Commit 7bfe54b5f165 ("powerpc/mm: Refactor the floor/ceiling check in hugetlb range freeing functions") inadvertely removed the mask applied to start parameter in those two functions, leading to the following crash on power9. LTP: starting hugemmap05_1 (hugemmap05 -m) ------------[ cut here ]------------ kernel BUG at arch/powerpc/mm/book3s64/pgtable.c:387! Oops: Exception in kernel mode, sig: 5 [#1] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=256 NUMA PowerNV ... CPU: 99 PID: 308 Comm: ksoftirqd/99 Tainted: G O 5.10.0-rc7-next-20201211 #1 NIP: c00000000005dbec LR: c0000000003352f4 CTR: 0000000000000000 REGS: c00020000bb6f830 TRAP: 0700 Tainted: G O (5.10.0-rc7-next-20201211) MSR: 900000000282b033 <SF,HV,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 24002284 XER: 20040000 GPR00: c0000000003352f4 c00020000bb6fad0 c000000007f70b00 c0002000385b3ff0 GPR04: 0000000000000000 0000000000000003 c00020000bb6f8b4 0000000000000001 GPR08: 0000000000000001 0000000000000009 0000000000000008 0000000000000002 GPR12: 0000000024002488 c000201fff649c00 c000000007f2a20c 0000000000000000 GPR16: 0000000000000007 0000000000000000 c000000000194d10 c000000000194d10 GPR24: 0000000000000014 0000000000000015 c000201cc6e72398 c000000007fac4b4 GPR28: c000000007f2bf80 c000000007fac2f8 0000000000000008 c000200033870000 NIP [c00000000005dbec] __tlb_remove_table+0x1dc/0x1e0 pgtable_free at arch/powerpc/mm/book3s64/pgtable.c:387 (inlined by) __tlb_remove_table at arch/powerpc/mm/book3s64/pgtable.c:405 LR [c0000000003352f4] tlb_remove_table_rcu+0x54/0xa0 Call Trace: __tlb_remove_table+0x13c/0x1e0 (unreliable) tlb_remove_table_rcu+0x54/0xa0 __tlb_remove_table_free at mm/mmu_gather.c:101 (inlined by) tlb_remove_table_rcu at mm/mmu_gather.c:156 rcu_core+0x35c/0xbb0 rcu_do_batch at kernel/rcu/tree.c:2502 (inlined by) rcu_core at kernel/rcu/tree.c:2737 __do_softirq+0x480/0x704 run_ksoftirqd+0x74/0xd0 run_ksoftirqd at kernel/softirq.c:651 (inlined by) run_ksoftirqd at kernel/softirq.c:642 smpboot_thread_fn+0x278/0x320 kthread+0x1c4/0x1d0 ret_from_kernel_thread+0x5c/0x80 Properly apply the masks before calling pmd_free_tlb() and pud_free_tlb() respectively. Fixes: 7bfe54b5f165 ("powerpc/mm: Refactor the floor/ceiling check in hugetlb range freeing functions") Reported-by: Qian Cai <qcai@redhat.com> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/56feccd7b6fcd98e353361a233fa7bb8e67c3164.1607780469.git.christophe.leroy@csgroup.eu
2020-12-14Merge tag 'core-mm-2020-12-14' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull kmap updates from Thomas Gleixner: "The new preemtible kmap_local() implementation: - Consolidate all kmap_atomic() internals into a generic implementation which builds the base for the kmap_local() API and make the kmap_atomic() interface wrappers which handle the disabling/enabling of preemption and pagefaults. - Switch the storage from per-CPU to per task and provide scheduler support for clearing mapping when scheduling out and restoring them when scheduling back in. - Merge the migrate_disable/enable() code, which is also part of the scheduler pull request. This was required to make the kmap_local() interface available which does not disable preemption when a mapping is established. It has to disable migration instead to guarantee that the virtual address of the mapped slot is the same across preemption. - Provide better debug facilities: guard pages and enforced utilization of the mapping mechanics on 64bit systems when the architecture allows it. - Provide the new kmap_local() API which can now be used to cleanup the kmap_atomic() usage sites all over the place. Most of the usage sites do not require the implicit disabling of preemption and pagefaults so the penalty on 64bit and 32bit non-highmem systems is removed and quite some of the code can be simplified. A wholesale conversion is not possible because some usage depends on the implicit side effects and some need to be cleaned up because they work around these side effects. The migrate disable side effect is only effective on highmem systems and when enforced debugging is enabled. On 64bit and 32bit non-highmem systems the overhead is completely avoided" * tag 'core-mm-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits) ARM: highmem: Fix cache_is_vivt() reference x86/crashdump/32: Simplify copy_oldmem_page() io-mapping: Provide iomap_local variant mm/highmem: Provide kmap_local* sched: highmem: Store local kmaps in task struct x86: Support kmap_local() forced debugging mm/highmem: Provide CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP mm/highmem: Provide and use CONFIG_DEBUG_KMAP_LOCAL microblaze/mm/highmem: Add dropped #ifdef back xtensa/mm/highmem: Make generic kmap_atomic() work correctly mm/highmem: Take kmap_high_get() properly into account highmem: High implementation details and document API Documentation/io-mapping: Remove outdated blurb io-mapping: Cleanup atomic iomap mm/highmem: Remove the old kmap_atomic cruft highmem: Get rid of kmap_types.h xtensa/mm/highmem: Switch to generic kmap atomic sparc/mm/highmem: Switch to generic kmap atomic powerpc/mm/highmem: Switch to generic kmap atomic nds32/mm/highmem: Switch to generic kmap atomic ...
2020-12-15powerpc: Inline setup_kup()Michael Ellerman
setup_kup() is used by both 64-bit and 32-bit code. However on 64-bit it must not be __init, because it's used for CPU hotplug, whereas on 32-bit it should be __init because it calls setup_kuap/kuep() which are __init. We worked around that problem in the past by marking it __ref, see commit 67d53f30e23e ("powerpc/mm: fix section mismatch for setup_kup()"). Marking it __ref basically just omits it from section mismatch checking, which can lead to bugs, and in fact it did, see commit 44b4c4450f8d ("powerpc/64s: Mark the kuap/kuep functions non __init") We can avoid all these problems by just making it static inline. Because all it does is call other functions, making it inline actually shrinks the 32-bit vmlinux by ~76 bytes. Make it __always_inline as pointed out by Christophe. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201214123011.311024-1-mpe@ellerman.id.au
2020-12-14powerpc/64s: Mark the kuap/kuep functions non __initAneesh Kumar K.V
The kernel calls these functions on CPU online and hence they must not be marked __init. Otherwise if the memory they occupied has been reused the system can crash in various ways. Sachin reported it caused his LPAR to spontaneously restart with no other output. With xmon enabled it may drop into xmon with a dump like: cpu 0x1: Vector: 700 (Program Check) at [c000000003c5fcb0] pc: 00000000011e0a78 lr: 00000000011c51d4 sp: c000000003c5ff50 msr: 8000000000081001 current = 0xc000000002c12b00 paca = 0xc000000003cff280 irqmask: 0x03 irq_happened: 0x01 pid = 0, comm = swapper/1 ... [c000000003c5ff50] 0000000000087c38 (unreliable) [c000000003c5ff70] 000000000003870c [c000000003c5ff90] 000000000000d108 Fixes: 3b47b7549ead ("powerpc/book3s64/kuap: Move KUAP related function outside radix") Reported-by: Sachin Sant <sachinp@linux.vnet.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> [mpe: Expand change log with details and xmon output] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201214080121.358567-1-aneesh.kumar@linux.ibm.com
2020-12-10Merge tag 'powerpc-5.10-6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc fix from Michael Ellerman: "One commit to implement copy_from_kernel_nofault_allowed(), otherwise copy_from_kernel_nofault() can trigger warnings when accessing bad addresses in some configurations. Thanks to Christophe Leroy and Qian Cai" * tag 'powerpc-5.10-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/mm: Fix KUAP warning by providing copy_from_kernel_nofault_allowed()
2020-12-09powerpc/64s/iommu: Don't use atomic_ function on atomic64_t typeNicholas Piggin
Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20201111110723.3148665-3-npiggin@gmail.com
2020-12-09powerpc/32s: Cleanup around PTE_FLAGS_OFFSET in hash_low.SChristophe Leroy
PTE_FLAGS_OFFSET is defined in asm/page_32.h and used only in hash_low.S And PTE_FLAGS_OFFSET nullity depends on CONFIG_PTE_64BIT Instead of tests like #if (PTE_FLAGS_OFFSET != 0), use CONFIG_PTE_64BIT related code. Also move the definition of PTE_FLAGS_OFFSET into hash_low.S directly, that improves readability. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/f5bc21db7a33dab55924734e6060c2e9daed562e.1606247495.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/32s: In add_hash_page(), calculate VSID laterChristophe Leroy
VSID is only for create_hpte(). When _PAGE_HASHPTE is already set, add_hash_page() bails out without calling create_hpte() and doesn't need the value of VSID. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/3907199974c89b85a3441cf3f528751173b7649c.1606247495.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/32s: Remove unused counters incremented by create_hpte()Christophe Leroy
primary_pteg_full and htab_hash_searches are not used. Remove them. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/6470ab99e58c84a5445af43ce4d1d772b0dc3e93.1606247495.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/mm: Refactor the floor/ceiling check in hugetlb range freeing functionsChristophe Leroy
All hugetlb range freeing functions have a verification like the following, which only differs by the mask used, depending on the page table level. start &= MASK; if (start < floor) return; if (ceiling) { ceiling &= MASK; if (! ceiling) return; } if (end - 1 > ceiling - 1) return; Refactor that into a helper function which takes the mask as an argument, returning true when [start;end[ is not fully contained inside [floor;ceiling[ Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> 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/16a571bb32eb6e8cd44bda484c8d81cd8a25e6d7.1604668827.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/fault: Perform exception fixup in do_page_fault()Christophe Leroy
Exception fixup doesn't require the heady full regs saving, do it from do_page_fault() directly. For that, split bad_page_fault() in two parts. As bad_page_fault() can also be called from other places than handle_page_fault(), it will still perform exception fixup and fallback on __bad_page_fault(). handle_page_fault() directly calls __bad_page_fault() as the exception fixup will now be done by do_page_fault() Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/bd07d6fef9237614cd6d318d8f19faeeadaa816b.1607491748.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/fault: Avoid heavy search_exception_tables() verificationChristophe Leroy
search_exception_tables() is an heavy operation, we have to avoid it. When KUAP is selected, we'll know the fault has been blocked by KUAP. When it is blocked by KUAP, check whether we are in an expected userspace access place. If so, emit a warning to spot something is going work. Otherwise, just remain silent, it will likely Oops soon. When KUAP is not selected, it behaves just as if the address was already in the TLBs and no fault was generated. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/9870f01e293a5a76c4f4e4ddd4a6b0f63038c591.1607491748.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/mm: Move the WARN() out of bad_kuap_fault()Christophe Leroy
In order to prepare the removal of calls to search_exception_tables() on the fast path, move the WARN() out of bad_kuap_fault(). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/9501311014bd6507e04b27a0c3035186ccf65cd5.1607491748.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/fault: Unnest definition of page_fault_is_write() and ↵Christophe Leroy
page_fault_is_bad() To make it more readable, separate page_fault_is_write() and page_fault_is_bad() to avoir several levels of #ifdefs Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/6afaac2495248d68f94c438c5ec36b6010931de5.1607491748.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/mm: sanity_check_fault() should work for all, not only BOOK3SChristophe Leroy
The verification and message introduced by commit 374f3f5979f9 ("powerpc/mm/hash: Handle user access of kernel address gracefully") applies to all platforms, it should not be limited to BOOK3S. Make the BOOK3S version of sanity_check_fault() the one for all, and bail out earlier if not BOOK3S. Fixes: 374f3f5979f9 ("powerpc/mm/hash: Handle user access of kernel address gracefully") Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/fe199d5af3578d3bf80035d203a94d742a7a28af.1607491748.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/8xx: Always pin kernel text TLBChristophe Leroy
There is no big poing in not pinning kernel text anymore, as now we can keep pinned TLB even with things like DEBUG_PAGEALLOC. Remove CONFIG_PIN_TLB_TEXT, making it always right. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mpe: Drop ifdef around mmu_pin_tlb() to fix build errors] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/203b89de491e1379f1677a2685211b7c32adfff0.1606231483.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/32s: Handle PROTFAULT in hash_page() also for CONFIG_PPC_KUAPChristophe Leroy
On hash 32 bits, handling minor protection faults like unsetting dirty flag is heavy if done from the normal page_fault processing, because it implies hash table software lookup for flushing the entry and then a DSI is taken anyway to add the entry back. When KUAP was implemented, as explained in commit a68c31fc01ef ("powerpc/32s: Implement Kernel Userspace Access Protection"), protection faults has been diverted from hash_page() because hash_page() was not able to identify a KUAP fault. Implement KUAP verification in hash_page(), by clearing write permission when the access is a kernel access and Ks is 1. This works regardless of the address because kernel segments always have Ks set to 0 while user segments have Ks set to 0 only when kernel write to userspace is granted. Then protection faults can be handled by hash_page() even for KUAP. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/8a4ffe4798e9ea32aaaccdf85e411bb1beed3500.1605542955.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/32s: Move early_mmu_init() into mmu.cChristophe Leroy
early_mmu_init() is independent of MMU type and not directly linked to tlb handling. In a following patch, tlb.c will be restricted to HASH mmu. Move early_mmu_init() into mmu.c which is common. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/e51b5e2fe6bca623b33116403043d3a1b5eaf826.1603348103.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/32s: Inline flush_hash_entry()Christophe Leroy
flush_hash_entry() is a simple function calling flush_hash_pages() if it's a hash MMU or doing nothing otherwise. Inline it. And use it also in __ptep_test_and_clear_young(). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/9af895be7d4b404d40e749a2659552fd138e62c4.1603348103.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/32s: Inline tlb_flush()Christophe Leroy
On book3s/32, tlb_flush() does nothing when the CPU has a hash table, it calls _tlbia() otherwise. Inline it. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/ebc933d1c530a19ef3cf7983f6ae94814f6e92ac.1603348103.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/32s: Split and inline flush_range()Christophe Leroy
flush_range() handle both the MMU_FTR_HPTE_TABLE case and the other case. The non MMU_FTR_HPTE_TABLE case is trivial as it is only a call to _tlbie()/_tlbia() which is not worth a dedicated function. Make flush_range() a hash specific and call it from tlbflush.h based on mmu_has_feature(MMU_FTR_HPTE_TABLE). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/132ab19aae52abc8e06ab524ec86d4229b5b9c3d.1603348103.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/32s: Inline flush_tlb_range() and flush_tlb_kernel_range()Christophe Leroy
flush_tlb_range() and flush_tlb_kernel_range() are trivial calls to flush_range(). Make flush_range() global and inline flush_tlb_range() and flush_tlb_kernel_range(). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/c7029a78e78709ad9272d7a44260e06b649169b2.1603348103.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/32s: Split and inline flush_tlb_mm() and flush_tlb_page()Christophe Leroy
flush_tlb_mm() and flush_tlb_page() handle both the MMU_FTR_HPTE_TABLE case and the other case. The non MMU_FTR_HPTE_TABLE case is trivial as it is only a call to _tlbie()/_tlbia() which is not worth a dedicated function. Make flush_tlb_mm() and flush_tlb_page() hash specific and call them from tlbflush.h based on mmu_has_feature(MMU_FTR_HPTE_TABLE). Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/11e932ded41ba6d9b251d89b7afa33cc060d3aa4.1603348103.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/32s: Move _tlbie() and _tlbia() in a new fileChristophe Leroy
_tlbie() and _tlbia() are used only on 603 cores while the other functions are used only on cores having a hash table. Move them into a new file named nohash_low.S Add mmu_hash_lock var is used by both, it needs to go in a common file. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/9a265b1b17a64153463d361280cb4b43eb1266a4.1603348103.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/32s: Inline _tlbie() on non SMPChristophe Leroy
On non SMP, _tlbie() is just a tlbie plus a sync instruction. Make it static inline. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/475136425541db5c7c8a0395d19d400525b251bc.1603348103.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/32s: Move _tlbie() and _tlbia() prototypes to tlbflush.hChristophe Leroy
In order to use _tlbie() and _tlbia() directly from asm/book3s/32/tlbflush.h, move their prototypes from mm/mm_decl.h to there. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/867587af929973ad65f8ef6972f2474a80c1737a.1603348103.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/32s: Declare Hash related vars as __initdataChristophe Leroy
Hash related vars are used at init only. Declare them in __initdata. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/3878ea30706839fcff9196790ff3f99c128c3f6a.1603348103.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/32s: Make Hash var staticChristophe Leroy
Hash var is used only locally in mmu.c now. No need to set it in head_32.S anymore. Make it static and initialises it to the early hash table. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/786c82a89cdfdaabb32b72a44f7c312fa81d192b.1603348103.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/32s: Use mmu_has_feature(MMU_FTR_HPTE_TABLE) instead of checking ↵Christophe Leroy
Hash var We now have an early hash table on hash MMU, so no need to check Hash var to know if the Hash table is set of not. Use mmu_has_feature(MMU_FTR_HPTE_TABLE) instead. This will allow optimisation via jump_label. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/f1766631a9e014b6433f1a3c12c726ddfce34220.1603348103.git.christophe.leroy@csgroup.eu
2020-12-09powerpc/32s: Make bat_addrs[] staticChristophe Leroy
This table is used only locally. Declare it static. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/054fec0c139fc4c0a306360b360784733c0a6e65.1603348103.git.christophe.leroy@csgroup.eu
generated by cgit (git 2.34.1) at 2025-07-19 06:32:41 +0000