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2015-12-15arm64: reduce stack use in irq_handlerJames Morse2-8/+23
The code for switching to irq_stack stores three pieces of information on the stack, fp+lr, as a fake stack frame (that lets us walk back onto the interrupted tasks stack frame), and the address of the struct pt_regs that contains the register values from kernel entry. (which dump_backtrace() will print in any stack trace). To reduce this, we store fp, and the pointer to the struct pt_regs. unwind_frame() can recognise this as the irq_stack dummy frame, (as it only appears at the top of the irq_stack), and use the struct pt_regs values to find the missing interrupted link-register. Suggested-by: Will Deacon <[email protected]> Signed-off-by: James Morse <[email protected]> Signed-off-by: Will Deacon <[email protected]>
2015-12-15Merge branch 'aarch64/efi' into aarch64/for-next/coreWill Deacon1-317/+17
Merge in EFI memblock changes from Ard, which form the preparatory work for UEFI support on 32-bit ARM.
2015-12-14arm64: KVM: Cleanup asm-offset.cMarc Zyngier1-39/+0
As we've now rewritten most of our code-base in C, most of the KVM-specific code in asm-offset.c is useless. Delete-time again! Signed-off-by: Marc Zyngier <[email protected]> Acked-by: Christoffer Dall <[email protected]>
2015-12-14arm64: KVM: Turn system register numbers to an enumMarc Zyngier1-0/+1
Having the system register numbers as #defines has been a pain since day one, as the ordering is pretty fragile, and moving things around leads to renumbering and epic conflict resolutions. Now that we're mostly acessing the sysreg file in C, an enum is a much better type to use, and we can clean things up a bit. Signed-off-by: Marc Zyngier <[email protected]> Acked-by: Christoffer Dall <[email protected]>
2015-12-10arm64: mm: fold alternatives into .initMark Rutland2-9/+2
Currently we treat the alternatives separately from other data that's only used during initialisation, using separate .altinstructions and .altinstr_replacement linker sections. These are freed for general allocation separately from .init*. This is problematic as: * We do not remove execute permissions, as we do for .init, leaving the memory executable. * We pad between them, making the kernel Image bianry up to PAGE_SIZE bytes larger than necessary. This patch moves the two sections into the contiguous region used for .init*. This saves some memory, ensures that we remove execute permissions, and allows us to remove some code made redundant by this reorganisation. Signed-off-by: Mark Rutland <[email protected]> Cc: Andre Przywara <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: Jeremy Linton <[email protected]> Cc: Laura Abbott <[email protected]> Cc: Will Deacon <[email protected]> Signed-off-by: Will Deacon <[email protected]>
2015-12-10arm64: Remove redundant padding from linker scriptMark Rutland1-2/+0
Currently we place an ALIGN_DEBUG_RO between text and data for the .text and .init sections, and depending on configuration each of these may result in up to SECTION_SIZE bytes worth of padding (for DEBUG_RODATA_ALIGN). We make no distinction between the text and data in each of these sections at any point when creating the initial page tables in head.S. We also make no distinction when modifying the tables; __map_memblock, fixup_executable, mark_rodata_ro, and fixup_init only work at section granularity. Thus this padding is unnecessary. For the spit between init text and data we impose a minimum alignment of 16 bytes, but this is also unnecessary. The init data is output immediately after the padding before any symbols are defined, so this is not required to keep a symbol for linker a section array correctly associated with the data. Any objects within the section will be given at least their usual alignment regardless. This patch removes the redundant padding. Signed-off-by: Mark Rutland <[email protected]> Cc: Ard Biesheuvel <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: Jeremy Linton <[email protected]> Cc: Laura Abbott <[email protected]> Cc: Will Deacon <[email protected]> Signed-off-by: Will Deacon <[email protected]>
2015-12-10arm64: don't call C code with el0's fp registerJames Morse1-0/+2
On entry from el0, we save all the registers on the kernel stack, and restore them before returning. x29 remains unchanged when we call out to C code, which will store x29 as the frame-pointer on the stack. Instead, write 0 into x29 after entry from el0, to avoid any risk of tracing into user space. Signed-off-by: James Morse <[email protected]> Signed-off-by: Will Deacon <[email protected]>
2015-12-10arm64: when walking onto the task stack, check sp & fp are in current->stackJames Morse1-2/+10
When unwind_frame() reaches the bottom of the irq_stack, the last fp points to the original task stack. unwind_frame() uses IRQ_STACK_TO_TASK_STACK() to find the sp value. If either values is wrong, we may end up walking a corrupt stack. Check these values are sane by testing if they are both on the stack pointed to by current->stack. Signed-off-by: James Morse <[email protected]> Signed-off-by: Will Deacon <[email protected]>
2015-12-10arm64: Add this_cpu_ptr() assembler macro for use in entry.SJames Morse1-3/+1
irq_stack is a per_cpu variable, that needs to be access from entry.S. Use an assembler macro instead of the unreadable details. Signed-off-by: James Morse <[email protected]> Signed-off-by: Will Deacon <[email protected]>
2015-12-09arm64/efi: refactor EFI init and runtime code for reuse by 32-bit ARMArd Biesheuvel1-0/+23
This refactors the EFI init and runtime code that will be shared between arm64 and ARM so that it can be built for both archs. Reviewed-by: Matt Fleming <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Signed-off-by: Will Deacon <[email protected]>
2015-12-09arm64/efi: split off EFI init and runtime code for reuse by 32-bit ARMArd Biesheuvel1-325/+1
This splits off the early EFI init and runtime code that - discovers the EFI params and the memory map from the FDT, and installs the memblocks and config tables. - prepares and installs the EFI page tables so that UEFI Runtime Services can be invoked at the virtual address installed by the stub. This will allow it to be reused for 32-bit ARM. Reviewed-by: Matt Fleming <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Signed-off-by: Will Deacon <[email protected]>
2015-12-09arm64/efi: mark UEFI reserved regions as MEMBLOCK_NOMAPArd Biesheuvel1-3/+4
Change the EFI memory reservation logic to use memblock_mark_nomap() rather than memblock_reserve() to mark UEFI reserved regions as occupied. In addition to reserving them against allocations done by memblock, this will also prevent them from being covered by the linear mapping. Reviewed-by: Matt Fleming <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Signed-off-by: Will Deacon <[email protected]>
2015-12-09arm64: irq: fix walking from irq stack to task stackWill Deacon1-1/+1
Running with CONFIG_DEBUG_SPINLOCK=y can trigger a BUG with the new IRQ stack code: BUG: spinlock lockup suspected on CPU#1 This is due to the IRQ_STACK_TO_TASK_STACK macro incorrectly retrieving the task stack pointer stashed at the top of the IRQ stack. Sayeth James: | Yup, this is what is happening. Its an off-by-one due to broken | thinking about how the stack works. My broken thinking was: | | > top ------------ | > | dummy_lr | <- irq_stack_ptr | > ------------ | > | x29 | | > ------------ | > | x19 | <- irq_stack_ptr - 0x10 | > ------------ | > | xzr | | > ------------ | | But the stack-pointer is decreased before use. So it actually looks | like this: | | > ------------ | > | | <- irq_stack_ptr | > top ------------ | > | dummy_lr | | > ------------ | > | x29 | <- irq_stack_ptr - 0x10 | > ------------ | > | x19 | | > ------------ | > | xzr | <- irq_stack_ptr - 0x20 | > ------------ | | The value being used as the original stack is x29, which in all the | tests is sp but without the current frames data, hence there are no | missing frames in the output. | | Jungseok Lee picked it up with a 32bit user space because aarch32 | can't use x29, so it remains 0 forever. The fix he posted is correct. This patch fixes the macro and adds some of this wisdom to a comment, so that the layout of the IRQ stack is well understood. Cc: James Morse <[email protected]> Reported-by: Jungseok Lee <[email protected]> Signed-off-by: Will Deacon <[email protected]>
2015-12-08arm64: Add do_softirq_own_stack() and enable irq_stacksJames Morse2-3/+77
entry.S is modified to switch to the per_cpu irq_stack during el{0,1}_irq. irq_count is used to detect recursive interrupts on the irq_stack, it is updated late by do_softirq_own_stack(), when called on the irq_stack, before __do_softirq() re-enables interrupts to process softirqs. do_softirq_own_stack() is added by this patch, but does not yet switch stack. This patch adds the dummy stack frame and data needed by the previous stack tracing patches. Reviewed-by: Catalin Marinas <[email protected]> Signed-off-by: James Morse <[email protected]> Signed-off-by: Will Deacon <[email protected]>
2015-12-08arm64: Modify stack trace and dump for use with irq_stackAKASHI Takahiro3-3/+43
This patch allows unwind_frame() to traverse from interrupt stack to task stack correctly. It requires data from a dummy stack frame, created during irq_stack_entry(), added by a later patch. A similar approach is taken to modify dump_backtrace(), which expects to find struct pt_regs underneath any call to functions marked __exception. When on an irq_stack, the struct pt_regs is stored on the old task stack, the location of which is stored in the dummy stack frame. Reviewed-by: Catalin Marinas <[email protected]> Signed-off-by: AKASHI Takahiro <[email protected]> [james.morse: merged two patches, reworked for per_cpu irq_stacks, and no alignment guarantees, added irq_stack definitions] Signed-off-by: James Morse <[email protected]> Signed-off-by: Will Deacon <[email protected]>
2015-12-08arm64: Store struct thread_info in sp_el0Jungseok Lee3-3/+20
There is need for figuring out how to manage struct thread_info data when IRQ stack is introduced. struct thread_info information should be copied to IRQ stack under the current thread_info calculation logic whenever context switching is invoked. This is too expensive to keep supporting the approach. Instead, this patch pays attention to sp_el0 which is an unused scratch register in EL1 context. sp_el0 utilization not only simplifies the management, but also prevents text section size from being increased largely due to static allocated IRQ stack as removing masking operation using THREAD_SIZE in many places. Reviewed-by: Catalin Marinas <[email protected]> Signed-off-by: Jungseok Lee <[email protected]> Signed-off-by: James Morse <[email protected]> Signed-off-by: Will Deacon <[email protected]>
2015-12-07arm64: Clear out any singlestep state on a ptrace detach operationJohn Blackwood1-0/+6
Make sure to clear out any ptrace singlestep state when a ptrace(2) PTRACE_DETACH call is made on arm64 systems. Otherwise, the previously ptraced task will die off with a SIGTRAP signal if the debugger just previously singlestepped the ptraced task. Cc: <[email protected]> Signed-off-by: John Blackwood <[email protected]> [will: added comment to justify why this is in the arch code] Signed-off-by: Will Deacon <[email protected]>
2015-12-07arm64: update linker script to increased L1_CACHE_BYTES valueArd Biesheuvel1-2/+3
Bring the linker script in line with the recent increase of L1_CACHE_BYTES to 128. Replace the hardcoded value of 64 with the symbolic constant. Signed-off-by: Ard Biesheuvel <[email protected]> Acked-by: Mark Rutland <[email protected]> [[email protected]: fix up RW_DATA_SECTION as well] Signed-off-by: Catalin Marinas <[email protected]>
2015-12-04arm64: Add trace_hardirqs_off annotation in ret_to_userCatalin Marinas1-0/+3
When a kernel is built with CONFIG_TRACE_IRQFLAGS the following warning is produced when entering userspace for the first time: WARNING: at /work/Linux/linux-2.6-aarch64/kernel/locking/lockdep.c:3519 Modules linked in: CPU: 1 PID: 1 Comm: systemd Not tainted 4.4.0-rc3+ #639 Hardware name: Juno (DT) task: ffffffc9768a0000 ti: ffffffc9768a8000 task.ti: ffffffc9768a8000 PC is at check_flags.part.22+0x19c/0x1a8 LR is at check_flags.part.22+0x19c/0x1a8 pc : [<ffffffc0000fba6c>] lr : [<ffffffc0000fba6c>] pstate: 600001c5 sp : ffffffc9768abe10 x29: ffffffc9768abe10 x28: ffffffc9768a8000 x27: 0000000000000000 x26: 0000000000000001 x25: 00000000000000a6 x24: ffffffc00064be6c x23: ffffffc0009f249e x22: ffffffc9768a0000 x21: ffffffc97fea5480 x20: 00000000000001c0 x19: ffffffc00169a000 x18: 0000005558cc7b58 x17: 0000007fb78e3180 x16: 0000005558d2e238 x15: ffffffffffffffff x14: 0ffffffffffffffd x13: 0000000000000008 x12: 0101010101010101 x11: 7f7f7f7f7f7f7f7f x10: fefefefefefeff63 x9 : 7f7f7f7f7f7f7f7f x8 : 6e655f7371726964 x7 : 0000000000000001 x6 : ffffffc0001079c4 x5 : 0000000000000000 x4 : 0000000000000001 x3 : ffffffc001698438 x2 : 0000000000000000 x1 : ffffffc9768a0000 x0 : 000000000000002e Call trace: [<ffffffc0000fba6c>] check_flags.part.22+0x19c/0x1a8 [<ffffffc0000fc440>] lock_is_held+0x80/0x98 [<ffffffc00064bafc>] __schedule+0x404/0x730 [<ffffffc00064be6c>] schedule+0x44/0xb8 [<ffffffc000085bb0>] ret_to_user+0x0/0x24 possible reason: unannotated irqs-off. irq event stamp: 502169 hardirqs last enabled at (502169): [<ffffffc000085a98>] el0_irq_naked+0x1c/0x24 hardirqs last disabled at (502167): [<ffffffc0000bb3bc>] __do_softirq+0x17c/0x298 softirqs last enabled at (502168): [<ffffffc0000bb43c>] __do_softirq+0x1fc/0x298 softirqs last disabled at (502143): [<ffffffc0000bb830>] irq_exit+0xa0/0xf0 This happens because we disable interrupts in ret_to_user before calling schedule() in work_resched. This patch adds the necessary trace_hardirqs_off annotation. Signed-off-by: Catalin Marinas <[email protected]> Reported-by: Mark Rutland <[email protected]> Cc: Will Deacon <[email protected]> Signed-off-by: Will Deacon <[email protected]>
2015-12-04arm64: ftrace: fix the comments for ftrace_modify_codeLi Bin1-6/+5
There is no need to worry about module and __init text disappearing case, because that ftrace has a module notifier that is called when a module is being unloaded and before the text goes away and this code grabs the ftrace_lock mutex and removes the module functions from the ftrace list, such that it will no longer do any modifications to that module's text, the update to make functions be traced or not is done under the ftrace_lock mutex as well. And by now, __init section codes should not been modified by ftrace, because it is black listed in recordmcount.c and ignored by ftrace. Suggested-by: Steven Rostedt <[email protected]> Signed-off-by: Li Bin <[email protected]> Signed-off-by: Will Deacon <[email protected]>
2015-12-04arm64: ftrace: stop using kstop_machine to enable/disable tracingLi Bin1-0/+5
For ftrace on arm64, kstop_machine which is hugely disruptive to a running system is not needed to convert nops to ftrace calls or back, because that to be modified instrucions, that NOP, B or BL, are all safe instructions which called "concurrent modification and execution of instructions", that can be executed by one thread of execution as they are being modified by another thread of execution without requiring explicit synchronization. Signed-off-by: Li Bin <[email protected]> Reviewed-by: Steven Rostedt <[email protected]> Signed-off-by: Will Deacon <[email protected]>
2015-12-02arm64: add __init/__initdata section marker to some functions/variablesJisheng Zhang3-8/+9
These functions/variables are not needed after booting, so mark them as __init or __initdata. Signed-off-by: Jisheng Zhang <[email protected]> Signed-off-by: Will Deacon <[email protected]>
2015-11-27Merge tag 'arm64-fixes' of ↵Linus Torvalds2-27/+43
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 fixes from Catalin Marinas: - Build fix when !CONFIG_UID16 (the patch is touching generic files but it only affects arm64 builds; submitted by Arnd Bergmann) - EFI fixes to deal with early_memremap() returning NULL and correctly mapping run-time regions - Fix CPUID register extraction of unsigned fields (not to be sign-extended) - ASID allocator fix to deal with long-running tasks over multiple generation roll-overs - Revert support for marking page ranges as contiguous PTEs (it leads to TLB conflicts and requires additional non-trivial kernel changes) - Proper early_alloc() failure check - Disable KASan for 48-bit VA and 16KB page configuration (the pgd is larger than the KASan shadow memory) - Update the fault_info table (original descriptions based on early engineering spec) * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: efi: fix initcall return values arm64: efi: deal with NULL return value of early_memremap() arm64: debug: Treat the BRPs/WRPs as unsigned arm64: cpufeature: Track unsigned fields arm64: cpufeature: Add helpers for extracting unsigned values Revert "arm64: Mark kernel page ranges contiguous" arm64: mm: keep reserved ASIDs in sync with mm after multiple rollovers arm64: KASAN depends on !(ARM64_16K_PAGES && ARM64_VA_BITS_48) arm64: efi: correctly map runtime regions arm64: mm: fix fault_info table xFSC decoding arm64: fix building without CONFIG_UID16 arm64: early_alloc: Fix check for allocation failure
2015-11-26arm64: efi: fix initcall return valuesArd Biesheuvel1-5/+5
Even though initcall return values are typically ignored, the prototype is to return 0 on success or a negative errno value on error. So fix the arm_enable_runtime_services() implementation to return 0 on conditions that are not in fact errors, and return a meaningful error code otherwise. Signed-off-by: Ard Biesheuvel <[email protected]> Reviewed-by: Matt Fleming <[email protected]> Acked-by: Will Deacon <[email protected]> Signed-off-by: Catalin Marinas <[email protected]>
2015-11-26arm64: efi: deal with NULL return value of early_memremap()Ard Biesheuvel1-1/+13
Add NULL return value checks to two invocations of early_memremap() in the UEFI init code. For the UEFI configuration tables, we just warn since we have a better chance of being able to report the issue in a way that can actually be noticed by a human operator if we don't abort right away. For the UEFI memory map, however, all we can do is panic() since we cannot proceed without a description of memory. Signed-off-by: Ard Biesheuvel <[email protected]> Reviewed-by: Matt Fleming <[email protected]> Acked-by: Will Deacon <[email protected]> Signed-off-by: Catalin Marinas <[email protected]>
2015-11-26arm64: cpufeature: Track unsigned fieldsSuzuki K. Poulose1-14/+23
Some of the feature bits have unsigned values and need to be treated accordingly to avoid errors. Adds the property to the feature bits and use the appropriate field extract helpers. Reported-by: AKASHI Takahiro <[email protected]> Cc: Ard Biesheuvel <[email protected]> Signed-off-by: Suzuki K. Poulose <[email protected]> Signed-off-by: Catalin Marinas <[email protected]>
2015-11-25arm64: efi: correctly map runtime regionsMark Rutland1-7/+2
The kernel may use a page granularity of 4K, 16K, or 64K depending on configuration. When mapping EFI runtime regions, we use memrange_efi_to_native to round the physical base address of a region down to a kernel page boundary, and round the size up to a kernel page boundary, adding the residue left over from rounding down the physical base address. We do not round down the virtual base address. In __create_mapping we account for the offset of the virtual base from a granule boundary, adding the residue to the size before rounding the base down to said granule boundary. Thus we account for the residue twice, and when the residue is non-zero will cause __create_mapping to map an additional page at the end of the region. Depending on the memory map, this page may be in a region we are not intended/permitted to map, or may clash with a different region that we wish to map. In typical cases, mapping the next item in the memory map will overwrite the erroneously created entry, as we sort the memory map in the stub. As __create_mapping can cope with base addresses which are not page aligned, we can instead rely on it to map the region appropriately, and simplify efi_virtmap_init by removing the unnecessary code. Signed-off-by: Mark Rutland <[email protected]> Reviewed-by: Ard Biesheuvel <[email protected]> Cc: Leif Lindholm <[email protected]> Cc: Will Deacon <[email protected]> Signed-off-by: Catalin Marinas <[email protected]>
2015-11-24arm64: KVM: Add workaround for Cortex-A57 erratum 834220Marc Zyngier1-0/+9
Cortex-A57 parts up to r1p2 can misreport Stage 2 translation faults when a Stage 1 permission fault or device alignment fault should have been reported. This patch implements the workaround (which is to validate that the Stage-1 translation actually succeeds) by using code patching. Cc: [email protected] Reviewed-by: Will Deacon <[email protected]> Signed-off-by: Marc Zyngier <[email protected]> Signed-off-by: Christoffer Dall <[email protected]>
2015-11-19arm64: restore bogomips information in /proc/cpuinfoYang Shi1-0/+5
As previously reported, some userspace applications depend on bogomips showed by /proc/cpuinfo. Although there is much less legacy impact on aarch64 than arm, it does break libvirt. This patch reverts commit 326b16db9f69 ("arm64: delay: don't bother reporting bogomips in /proc/cpuinfo"), but with some tweak due to context change and without the pr_info(). Fixes: 326b16db9f69 ("arm64: delay: don't bother reporting bogomips in /proc/cpuinfo") Signed-off-by: Yang Shi <[email protected]> Acked-by: Will Deacon <[email protected]> Cc: <[email protected]> # 3.12+ Signed-off-by: Catalin Marinas <[email protected]>
2015-11-18arm64: use non-global mappings for UEFI runtime regionsArd Biesheuvel1-9/+5
As pointed out by Russell King in response to the proposed ARM version of this code, the sequence to switch between the UEFI runtime mapping and current's actual userland mapping (and vice versa) is potentially unsafe, since it leaves a time window between the switch to the new page tables and the TLB flush where speculative accesses may hit on stale global TLB entries. So instead, use non-global mappings, and perform the switch via the ordinary ASID-aware context switch routines. Signed-off-by: Ard Biesheuvel <[email protected]> Acked-by: Will Deacon <[email protected]> Reviewed-by: Mark Rutland <[email protected]> Signed-off-by: Catalin Marinas <[email protected]>
2015-11-17arm64: kernel: pause/unpause function graph tracer in cpu_suspend()Lorenzo Pieralisi1-0/+10
The function graph tracer adds instrumentation that is required to trace both entry and exit of a function. In particular the function graph tracer updates the "return address" of a function in order to insert a trace callback on function exit. Kernel power management functions like cpu_suspend() are called upon power down entry with functions called "finishers" that are in turn called to trigger the power down sequence but they may not return to the kernel through the normal return path. When the core resumes from low-power it returns to the cpu_suspend() function through the cpu_resume path, which leaves the trace stack frame set-up by the function tracer in an incosistent state upon return to the kernel when tracing is enabled. This patch fixes the issue by pausing/resuming the function graph tracer on the thread executing cpu_suspend() (ie the function call that subsequently triggers the "suspend finishers"), so that the function graph tracer state is kept consistent across functions that enter power down states and never return by effectively disabling graph tracer while they are executing. Fixes: 819e50e25d0c ("arm64: Add ftrace support") Signed-off-by: Lorenzo Pieralisi <[email protected]> Reported-by: Catalin Marinas <[email protected]> Reported-by: AKASHI Takahiro <[email protected]> Suggested-by: Steven Rostedt <[email protected]> Acked-by: Steven Rostedt <[email protected]> Cc: Will Deacon <[email protected]> Cc: <[email protected]> # 3.16+ Signed-off-by: Catalin Marinas <[email protected]>
2015-11-16arm64: perf: Add event descriptionsDrew Richardson1-0/+138
Add additional information about the ARM architected hardware events to make counters self describing. This makes the hardware PMUs easier to use as perf list contains possible events instead of users having to refer to documentation like the ARM TRMs. Signed-off-by: Drew Richardson <[email protected]> Signed-off-by: Will Deacon <[email protected]>
2015-11-16arm64: perf: Convert event enums to #definesDrew Richardson1-50/+45
The enums are not necessary and this allows the event values to be used to construct static strings at compile time. Signed-off-by: Drew Richardson <[email protected]> Signed-off-by: Will Deacon <[email protected]>
2015-11-12Merge tag 'arm64-fixes' of ↵Linus Torvalds4-3/+6
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 fixes and clean-ups from Catalin Marinas: "Here's a second pull request for this merging window with some fixes/clean-ups: - __cmpxchg_double*() return type fix to avoid truncation of a long to int and subsequent logical "not" in cmpxchg_double() misinterpreting the operation success/failure - BPF fixes for mod and div by zero - Fix compilation with STRICT_MM_TYPECHECKS enabled - VDSO build fix without libgcov - Some static and __maybe_unused annotations - Kconfig clean-up (FRAME_POINTER) - defconfig update for CRYPTO_CRC32_ARM64" * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: suspend: make hw_breakpoint_restore static arm64: mmu: make split_pud and fixup_executable static arm64: smp: make of_parse_and_init_cpus static arm64: use linux/types.h in kvm.h arm64: build vdso without libgcov arm64: mark cpus_have_hwcap as __maybe_unused arm64: remove redundant FRAME_POINTER kconfig option and force to select it arm64: fix R/O permissions of FDT mapping arm64: fix STRICT_MM_TYPECHECKS issue in PTE_CONT manipulation arm64: bpf: fix mod-by-zero case arm64: bpf: fix div-by-zero case arm64: Enable CRYPTO_CRC32_ARM64 in defconfig arm64: cmpxchg_dbl: fix return value type
2015-11-12arm64: suspend: make hw_breakpoint_restore staticJisheng Zhang1-1/+1
hw_breakpoint_restore is only used within suspend.c, so it can be declared static. Signed-off-by: Jisheng Zhang <[email protected]> Signed-off-by: Catalin Marinas <[email protected]>
2015-11-12arm64: smp: make of_parse_and_init_cpus staticJisheng Zhang1-1/+1
of_parse_and_init_cpus is only called from within smp.c, so it can be declared static. Signed-off-by: Jisheng Zhang <[email protected]> Signed-off-by: Catalin Marinas <[email protected]>
2015-11-12arm64: build vdso without libgcovArnd Bergmann1-0/+3
On a cross-toolchain without glibc support, libgcov may not be available, and attempting to build an arm64 kernel with GCOV enabled then results in a build error: /home/arnd/cross-gcc/lib/gcc/aarch64-linux/5.2.1/../../../../aarch64-linux/bin/ld: cannot find -lgcov We don't really want to link libgcov into the vdso anyway, so this patch just disables GCOV in the vdso directory, just as we do for most other architectures. Signed-off-by: Arnd Bergmann <[email protected]> Signed-off-by: Catalin Marinas <[email protected]>
2015-11-12arm64: mark cpus_have_hwcap as __maybe_unusedArnd Bergmann1-1/+1
cpus_have_hwcap() is defined as a 'static' function an only used in one place that is inside of an #ifdef, so we get a warning when the only user is disabled: arch/arm64/kernel/cpufeature.c:699:13: warning: 'cpus_have_hwcap' defined but not used [-Wunused-function] This marks the function as __maybe_unused, so the compiler knows that it can drop the function definition without warning about it. Signed-off-by: Arnd Bergmann <[email protected]> Fixes: 37b01d53ceef ("arm64/HWCAP: Use system wide safe values") Signed-off-by: Catalin Marinas <[email protected]>
2015-11-10Merge tag 'armsoc-drivers' of ↵Linus Torvalds1-14/+0
git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc Pull ARM SoC driver updates from Olof Johansson: "As we've enabled multiplatform kernels on ARM, and greatly done away with the contents under arch/arm/mach-*, there's still need for SoC-related drivers to go somewhere. Many of them go in through other driver trees, but we still have drivers/soc to hold some of the "doesn't fit anywhere" lowlevel code that might be shared between ARM and ARM64 (or just in general makes sense to not have under the architecture directory). This branch contains mostly such code: - Drivers for qualcomm SoCs for SMEM, SMD and SMD-RPM, used to communicate with power management blocks on these SoCs for use by clock, regulator and bus frequency drivers. - Allwinner Reduced Serial Bus driver, again used to communicate with PMICs. - Drivers for ARM's SCPI (System Control Processor). Not to be confused with PSCI (Power State Coordination Interface). SCPI is used to communicate with the assistant embedded cores doing power management, and we have yet to see how many of them will implement this for their hardware vs abstracting in other ways (or not at all like in the past). - To make confusion between SCPI and PSCI more likely, this release also includes an update of PSCI to interface version 1.0. - Rockchip support for power domains. - A driver to talk to the firmware on Raspberry Pi" * tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (57 commits) soc: qcom: smd-rpm: Correct size of outgoing message bus: sunxi-rsb: Add driver for Allwinner Reduced Serial Bus bus: sunxi-rsb: Add Allwinner Reduced Serial Bus (RSB) controller bindings ARM: bcm2835: add mutual inclusion protection drivers: psci: make PSCI 1.0 functions initialization version dependent dt-bindings: Correct paths in Rockchip power domains binding document soc: rockchip: power-domain: don't try to print the clock name in error case soc: qcom/smem: add HWSPINLOCK dependency clk: berlin: add cpuclk ARM: berlin: dts: add CLKID_CPU for BG2Q ARM: bcm2835: Add the Raspberry Pi firmware driver soc: qcom: smem: Move RPM message ram out of smem DT node soc: qcom: smd-rpm: Correct the active vs sleep state flagging soc: qcom: smd: delete unneeded of_node_put firmware: qcom-scm: build for correct architecture level soc: qcom: smd: Correct SMEM items for upper channels qcom-scm: add missing prototype for qcom_scm_is_available() qcom-scm: fix endianess issue in __qcom_scm_is_call_available soc: qcom: smd: Reject send of too big packets soc: qcom: smd: Handle big endian CPUs ...
2015-11-04Merge tag 'driver-core-4.4-rc1' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here's the "big" driver core updates for 4.4-rc1. Primarily a bunch of debugfs updates, with a smattering of minor driver core fixes and updates as well. All have been in linux-next for a long time" * tag 'driver-core-4.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: debugfs: Add debugfs_create_ulong() of: to support binding numa node to specified device in devicetree debugfs: Add read-only/write-only bool file ops debugfs: Add read-only/write-only size_t file ops debugfs: Add read-only/write-only x64 file ops debugfs: Consolidate file mode checks in debugfs_create_*() Revert "mm: Check if section present during memory block (un)registering" driver-core: platform: Provide helpers for multi-driver modules mm: Check if section present during memory block (un)registering devres: fix a for loop bounds check CMA: fix CONFIG_CMA_SIZE_MBYTES overflow in 64bit base/platform: assert that dev_pm_domain callbacks are called unconditionally sysfs: correctly handle short reads on PREALLOC attrs. base: soc: siplify ida usage kobject: move EXPORT_SYMBOL() macros next to corresponding definitions kobject: explain what kobject's sd field is debugfs: document that debugfs_remove*() accepts NULL and error values debugfs: Pass bool pointer to debugfs_create_bool() ACPI / EC: Fix broken 64bit big-endian users of 'global_lock'
2015-11-04Merge tag 'pm+acpi-4.4-rc1-1' of ↵Linus Torvalds2-32/+1
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management and ACPI updates from Rafael Wysocki: "Quite a new features are included this time. First off, the Collaborative Processor Performance Control interface (version 2) defined by ACPI will now be supported on ARM64 along with a cpufreq frontend for CPU performance scaling. Second, ACPI gets a new infrastructure for the early probing of IRQ chips and clock sources (along the lines of the existing similar mechanism for DT). Next, the ACPI core and the generic device properties API will now support a recently introduced hierarchical properties extension of the _DSD (Device Specific Data) ACPI device configuration object. If the ACPI platform firmware uses that extension to organize device properties in a hierarchical way, the kernel will automatically handle it and make those properties available to device drivers via the generic device properties API. It also will be possible to build the ACPICA's AML interpreter debugger into the kernel now and use that to diagnose AML-related problems more efficiently. In the future, this should make it possible to single-step AML execution and do similar things. Interesting stuff, although somewhat experimental at this point. Finally, the PM core gets a new mechanism that can be used by device drivers to distinguish between suspend-to-RAM (based on platform firmware support) and suspend-to-idle (or other variants of system suspend the platform firmware is not involved in) and possibly optimize their device suspend/resume handling accordingly. In addition to that, some existing features are re-organized quite substantially. First, the ACPI-based handling of PCI host bridges on x86 and ia64 is unified and the common code goes into the ACPI core (so as to reduce code duplication and eliminate non-essential differences between the two architectures in that area). Second, the Operating Performance Points (OPP) framework is reorganized to make the code easier to find and follow. Next, the cpufreq core's sysfs interface is reorganized to get rid of the "primary CPU" concept for configurations in which the same performance scaling settings are shared between multiple CPUs. Finally, some interfaces that aren't necessary any more are dropped from the generic power domains framework. On top of the above we have some minor extensions, cleanups and bug fixes in multiple places, as usual. Specifics: - ACPICA update to upstream revision 20150930 (Bob Moore, Lv Zheng). The most significant change is to allow the AML debugger to be built into the kernel. On top of that there is an update related to the NFIT table (the ACPI persistent memory interface) and a few fixes and cleanups. - ACPI CPPC2 (Collaborative Processor Performance Control v2) support along with a cpufreq frontend (Ashwin Chaugule). This can only be enabled on ARM64 at this point. - New ACPI infrastructure for the early probing of IRQ chips and clock sources (Marc Zyngier). - Support for a new hierarchical properties extension of the ACPI _DSD (Device Specific Data) device configuration object allowing the kernel to handle hierarchical properties (provided by the platform firmware this way) automatically and make them available to device drivers via the generic device properties interface (Rafael Wysocki). - Generic device properties API extension to obtain an index of certain string value in an array of strings, along the lines of of_property_match_string(), but working for all of the supported firmware node types, and support for the "dma-names" device property based on it (Mika Westerberg). - ACPI core fix to parse the MADT (Multiple APIC Description Table) entries in the order expected by platform firmware (and mandated by the specification) to avoid confusion on systems with more than 255 logical CPUs (Lukasz Anaczkowski). - Consolidation of the ACPI-based handling of PCI host bridges on x86 and ia64 (Jiang Liu). - ACPI core fixes to ensure that the correct IRQ number is used to represent the SCI (System Control Interrupt) in the cases when it has been re-mapped (Chen Yu). - New ACPI backlight quirk for Lenovo IdeaPad S405 (Hans de Goede). - ACPI EC driver fixes (Lv Zheng). - Assorted ACPI fixes and cleanups (Dan Carpenter, Insu Yun, Jiri Kosina, Rami Rosen, Rasmus Villemoes). - New mechanism in the PM core allowing drivers to check if the platform firmware is going to be involved in the upcoming system suspend or if it has been involved in the suspend the system is resuming from at the moment (Rafael Wysocki). This should allow drivers to optimize their suspend/resume handling in some cases and the changes include a couple of users of it (the i8042 input driver, PCI PM). - PCI PM fix to prevent runtime-suspended devices with PME enabled from being resumed during system suspend even if they aren't configured to wake up the system from sleep (Rafael Wysocki). - New mechanism to report the number of a wakeup IRQ that woke up the system from sleep last time (Alexandra Yates). - Removal of unused interfaces from the generic power domains framework and fixes related to latency measurements in that code (Ulf Hansson, Daniel Lezcano). - cpufreq core sysfs interface rework to make it handle CPUs that share performance scaling settings (represented by a common cpufreq policy object) more symmetrically (Viresh Kumar). This should help to simplify the CPU offline/online handling among other things. - cpufreq core fixes and cleanups (Viresh Kumar). - intel_pstate fixes related to the Turbo Activation Ratio (TAR) mechanism on client platforms which causes the turbo P-states range to vary depending on platform firmware settings (Srinivas Pandruvada). - intel_pstate sysfs interface fix (Prarit Bhargava). - Assorted cpufreq driver (imx, tegra20, powernv, integrator) fixes and cleanups (Bai Ping, Bartlomiej Zolnierkiewicz, Shilpasri G Bhat, Luis de Bethencourt). - cpuidle mvebu driver cleanups (Russell King). - OPP (Operating Performance Points) framework code reorganization to make it more maintainable (Viresh Kumar). - Intel Broxton support for the RAPL (Running Average Power Limits) power capping driver (Amy Wiles). - Assorted power management code fixes and cleanups (Dan Carpenter, Geert Uytterhoeven, Geliang Tang, Luis de Bethencourt, Rasmus Villemoes)" * tag 'pm+acpi-4.4-rc1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (108 commits) cpufreq: postfix policy directory with the first CPU in related_cpus cpufreq: create cpu/cpufreq/policyX directories cpufreq: remove cpufreq_sysfs_{create|remove}_file() cpufreq: create cpu/cpufreq at boot time cpufreq: Use cpumask_copy instead of cpumask_or to copy a mask cpufreq: ondemand: Drop unnecessary locks from update_sampling_rate() PM / Domains: Merge measurements for PM QoS device latencies PM / Domains: Don't measure ->start|stop() latency in system PM callbacks PM / clk: Fix broken build due to non-matching code and header #ifdefs ACPI / Documentation: add copy_dsdt to ACPI format options ACPI / sysfs: correctly check failing memory allocation ACPI / video: Add a quirk to force native backlight on Lenovo IdeaPad S405 ACPI / CPPC: Fix potential memory leak ACPI / CPPC: signedness bug in register_pcc_channel() ACPI / PAD: power_saving_thread() is not freezable ACPI / PM: Fix incorrect wakeup IRQ setting during suspend-to-idle ACPI: Using correct irq when waiting for events ACPI: Use correct IRQ when uninstalling ACPI interrupt handler cpuidle: mvebu: disable the bind/unbind attributes and use builtin_platform_driver cpuidle: mvebu: clean up multiple platform drivers ...
2015-11-04Merge tag 'arm64-upstream' of ↵Linus Torvalds24-1480/+1330
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: - "genirq: Introduce generic irq migration for cpu hotunplugged" patch merged from tip/irq/for-arm to allow the arm64-specific part to be upstreamed via the arm64 tree - CPU feature detection reworked to cope with heterogeneous systems where CPUs may not have exactly the same features. The features reported by the kernel via internal data structures or ELF_HWCAP are delayed until all the CPUs are up (and before user space starts) - Support for 16KB pages, with the additional bonus of a 36-bit VA space, though the latter only depending on EXPERT - Implement native {relaxed, acquire, release} atomics for arm64 - New ASID allocation algorithm which avoids IPI on roll-over, together with TLB invalidation optimisations (using local vs global where feasible) - KASan support for arm64 - EFI_STUB clean-up and isolation for the kernel proper (required by KASan) - copy_{to,from,in}_user optimisations (sharing the memcpy template) - perf: moving arm64 to the arm32/64 shared PMU framework - L1_CACHE_BYTES increased to 128 to accommodate Cavium hardware - Support for the contiguous PTE hint on kernel mapping (16 consecutive entries may be able to use a single TLB entry) - Generic CONFIG_HZ now used on arm64 - defconfig updates * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (91 commits) arm64/efi: fix libstub build under CONFIG_MODVERSIONS ARM64: Enable multi-core scheduler support by default arm64/efi: move arm64 specific stub C code to libstub arm64: page-align sections for DEBUG_RODATA arm64: Fix build with CONFIG_ZONE_DMA=n arm64: Fix compat register mappings arm64: Increase the max granular size arm64: remove bogus TASK_SIZE_64 check arm64: make Timer Interrupt Frequency selectable arm64/mm: use PAGE_ALIGNED instead of IS_ALIGNED arm64: cachetype: fix definitions of ICACHEF_* flags arm64: cpufeature: declare enable_cpu_capabilities as static genirq: Make the cpuhotplug migration code less noisy arm64: Constify hwcap name string arrays arm64/kvm: Make use of the system wide safe values arm64/debug: Make use of the system wide safe value arm64: Move FP/ASIMD hwcap handling to common code arm64/HWCAP: Use system wide safe values arm64/capabilities: Make use of system wide safe value arm64: Delay cpu feature capability checks ...
2015-11-03Merge branch 'core-efi-for-linus' of ↵Linus Torvalds2-16/+36
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull EFI changes from Ingo Molnar: "The main changes in this cycle were: - further EFI code generalization to make it more workable for ARM64 - various extensions, such as 64-bit framebuffer address support, UEFI v2.5 EFI_PROPERTIES_TABLE support - code modularization simplifications and cleanups - new debugging parameters - various fixes and smaller additions" * 'core-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits) efi: Fix warning of int-to-pointer-cast on x86 32-bit builds efi: Use correct type for struct efi_memory_map::phys_map x86/efi: Fix kernel panic when CONFIG_DEBUG_VIRTUAL is enabled efi: Add "efi_fake_mem" boot option x86/efi: Rename print_efi_memmap() to efi_print_memmap() efi: Auto-load the efi-pstore module efi: Introduce EFI_NX_PE_DATA bit and set it from properties table efi: Add support for UEFIv2.5 Properties table efi: Add EFI_MEMORY_MORE_RELIABLE support to efi_md_typeattr_format() efifb: Add support for 64-bit frame buffer addresses efi/arm64: Clean up efi_get_fdt_params() interface arm64: Use core efi=debug instead of uefi_debug command line parameter efi/x86: Move efi=debug option parsing to core drivers/firmware: Make efi/esrt.c driver explicitly non-modular efi: Use the generic efi.memmap instead of 'memmap' acpi/apei: Use appropriate pgprot_t to map GHES memory arm64, acpi/apei: Implement arch_apei_get_mem_attributes() arm64/mm: Add PROT_DEVICE_nGnRnE and PROT_NORMAL_WT acpi, x86: Implement arch_apei_get_mem_attributes() efi, x86: Rearrange efi_mem_attributes() ...
2015-11-03Merge branch 'irq-core-for-linus' of ↵Linus Torvalds3-1/+29
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq updates from Thomas Gleixner: "The irq departement delivers: - Rework the irqdomain core infrastructure to accomodate ACPI based systems. This is required to support ARM64 without creating artificial device tree nodes. - Sanitize the ACPI based ARM GIC initialization by making use of the new firmware independent irqdomain core - Further improvements to the generic MSI management - Generalize the irq migration on CPU hotplug - Improvements to the threaded interrupt infrastructure - Allow the migration of "chained" low level interrupt handlers - Allow optional force masking of interrupts in disable_irq[_nosysnc] - Support for two new interrupt chips - Sigh! - A larger set of errata fixes for ARM gicv3 - The usual pile of fixes, updates, improvements and cleanups all over the place" * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (71 commits) Document that IRQ_NONE should be returned when IRQ not actually handled PCI/MSI: Allow the MSI domain to be device-specific PCI: Add per-device MSI domain hook of/irq: Use the msi-map property to provide device-specific MSI domain of/irq: Split of_msi_map_rid to reuse msi-map lookup irqchip/gic-v3-its: Parse new version of msi-parent property PCI/MSI: Use of_msi_get_domain instead of open-coded "msi-parent" parsing of/irq: Use of_msi_get_domain instead of open-coded "msi-parent" parsing of/irq: Add support code for multi-parent version of "msi-parent" irqchip/gic-v3-its: Add handling of PCI requester id. PCI/MSI: Add helper function pci_msi_domain_get_msi_rid(). of/irq: Add new function of_msi_map_rid() Docs: dt: Add PCI MSI map bindings irqchip/gic-v2m: Add support for multiple MSI frames irqchip/gic-v3: Fix translation of LPIs after conversion to irq_fwspec irqchip/mxs: Add Alphascale ASM9260 support irqchip/mxs: Prepare driver for hardware with different offsets irqchip/mxs: Panic if ioremap or domain creation fails irqdomain: Documentation updates irqdomain/msi: Use fwnode instead of of_node ...
2015-10-30arm64/efi: move arm64 specific stub C code to libstubArd Biesheuvel2-75/+2
Now that we added special handling to the C files in libstub, move the one remaining arm64 specific EFI stub C file to libstub as well, so that it gets the same treatment. This should prevent future changes from resulting in binaries that may execute incorrectly in UEFI context. With efi-entry.S the only remaining EFI stub source file under arch/arm64, we can also simplify the Makefile logic somewhat. Signed-off-by: Ard Biesheuvel <[email protected]> Reviewed-by: Matt Fleming <[email protected]> Tested-by: Jeremy Linton <[email protected]> Signed-off-by: Catalin Marinas <[email protected]>
2015-10-29arm64: page-align sections for DEBUG_RODATAMark Rutland1-1/+4
A kernel built with DEBUG_RO_DATA && !CONFIG_DEBUG_ALIGN_RODATA doesn't have .text aligned to a page boundary, though fixup_executable works at page-granularity thanks to its use of create_mapping. If .text is not page-aligned, the first page it exists in may be marked non-executable, leading to failures when an attempt is made to execute code in said page. This patch upgrades ALIGN_DEBUG_RO and ALIGN_DEBUG_RO_MIN to force page alignment for DEBUG_RO_DATA && !CONFIG_DEBUG_ALIGN_RODATA kernels, ensuring that all sections with specific RWX permission requirements are mapped with the correct permissions. Signed-off-by: Mark Rutland <[email protected]> Reported-by: Jeremy Linton <[email protected]> Reviewed-by: Laura Abbott <[email protected]> Acked-by: Ard Biesheuvel <[email protected]> Cc: Suzuki Poulose <[email protected]> Cc: Will Deacon <[email protected]> Fixes: da141706aea52c1a ("arm64: add better page protections to arm64") Cc: <[email protected]> Signed-off-by: Catalin Marinas <[email protected]>
2015-10-29arm64/efi: do not assume DRAM base is aligned to 2 MBArd Biesheuvel1-2/+12
The current arm64 Image relocation code in the UEFI stub assumes that the dram_base argument it receives is always a multiple of 2 MB. In reality, it is simply the lowest start address of all RAM entries in the UEFI memory map, which means it could be any multiple of 4 KB. Since the arm64 kernel Image needs to reside TEXT_OFFSET bytes beyond a 2 MB aligned base, or it will fail to boot, make sure we round dram_base to 2 MB before using it to calculate the relocation address. Fixes: e38457c361b30c5a ("arm64: efi: prefer AllocatePages() over efi_low_alloc() for vmlinux") Reported-by: Timur Tabi <[email protected]> Tested-by: Timur Tabi <[email protected]> Acked-by: Mark Rutland <[email protected]> Signed-off-by: Ard Biesheuvel <[email protected]> Signed-off-by: Will Deacon <[email protected]>
2015-10-28arm64: cpufeature: declare enable_cpu_capabilities as staticWill Deacon1-1/+1
enable_cpu_capabilities is only called from within cpufeature.c, so it can be declared static. Signed-off-by: Will Deacon <[email protected]> Signed-off-by: Catalin Marinas <[email protected]>
2015-10-28Revert "ARM64: unwind: Fix PC calculation"Will Deacon1-5/+1
This reverts commit e306dfd06fcb44d21c80acb8e5a88d55f3d1cf63. With this patch applied, we were the only architecture making this sort of adjustment to the PC calculation in the unwinder. This causes problems for ftrace, where the PC values are matched against the contents of the stack frames in the callchain and fail to match any records after the address adjustment. Whilst there has been some effort to change ftrace to workaround this, those patches are not yet ready for mainline and, since we're the odd architecture in this regard, let's just step in line with other architectures (like arch/arm/) for now. Cc: <[email protected]> Signed-off-by: Will Deacon <[email protected]>
2015-10-28arm64: kernel: fix tcr_el1.t0sz restore on systems with extended idmapLorenzo Pieralisi1-9/+13
Commit dd006da21646 ("arm64: mm: increase VA range of identity map") introduced a mechanism to extend the virtual memory map range to support arm64 systems with system RAM located at very high offset, where the identity mapping used to enable/disable the MMU requires additional translation levels to map the physical memory at an equal virtual offset. The kernel detects at boot time the tcr_el1.t0sz value required by the identity mapping and sets-up the tcr_el1.t0sz register field accordingly, any time the identity map is required in the kernel (ie when enabling the MMU). After enabling the MMU, in the cold boot path the kernel resets the tcr_el1.t0sz to its default value (ie the actual configuration value for the system virtual address space) so that after enabling the MMU the memory space translated by ttbr0_el1 is restored as expected. Commit dd006da21646 ("arm64: mm: increase VA range of identity map") also added code to set-up the tcr_el1.t0sz value when the kernel resumes from low-power states with the MMU off through cpu_resume() in order to effectively use the identity mapping to enable the MMU but failed to add the code required to restore the tcr_el1.t0sz to its default value, when the core returns to the kernel with the MMU enabled, so that the kernel might end up running with tcr_el1.t0sz value set-up for the identity mapping which can be lower than the value required by the actual virtual address space, resulting in an erroneous set-up. This patchs adds code in the resume path that restores the tcr_el1.t0sz default value upon core resume, mirroring this way the cold boot path behaviour therefore fixing the issue. Cc: <[email protected]> Cc: Catalin Marinas <[email protected]> Fixes: dd006da21646 ("arm64: mm: increase VA range of identity map") Acked-by: Ard Biesheuvel <[email protected]> Signed-off-by: Lorenzo Pieralisi <[email protected]> Signed-off-by: James Morse <[email protected]> Signed-off-by: Will Deacon <[email protected]>