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2016-02-24arm64: Add a helper for parking CPUs in a loopSuzuki K Poulose1-0/+8
Adds a routine which can be used to park CPUs (spinning in kernel) when they can't be killed. Cc: Mark Rutland <mark.rutland@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-24arm64: add support for kernel ASLRArd Biesheuvel2-1/+10
This adds support for KASLR is implemented, based on entropy provided by the bootloader in the /chosen/kaslr-seed DT property. Depending on the size of the address space (VA_BITS) and the page size, the entropy in the virtual displacement is up to 13 bits (16k/2 levels) and up to 25 bits (all 4 levels), with the sidenote that displacements that result in the kernel image straddling a 1GB/32MB/512MB alignment boundary (for 4KB/16KB/64KB granule kernels, respectively) are not allowed, and will be rounded up to an acceptable value. If CONFIG_RANDOMIZE_MODULE_REGION_FULL is enabled, the module region is randomized independently from the core kernel. This makes it less likely that the location of core kernel data structures can be determined by an adversary, but causes all function calls from modules into the core kernel to be resolved via entries in the module PLTs. If CONFIG_RANDOMIZE_MODULE_REGION_FULL is not enabled, the module region is randomized by choosing a page aligned 128 MB region inside the interval [_etext - 128 MB, _stext + 128 MB). This gives between 10 and 14 bits of entropy (depending on page size), independently of the kernel randomization, but still guarantees that modules are within the range of relative branch and jump instructions (with the caveat that, since the module region is shared with other uses of the vmalloc area, modules may need to be loaded further away if the module region is exhausted) Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-24arm64: add support for building vmlinux as a relocatable PIE binaryArd Biesheuvel1-0/+2
This implements CONFIG_RELOCATABLE, which links the final vmlinux image with a dynamic relocation section, allowing the early boot code to perform a relocation to a different virtual address at runtime. This is a prerequisite for KASLR (CONFIG_RANDOMIZE_BASE). Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-24arm64: switch to relative exception tablesArd Biesheuvel5-44/+39
Instead of using absolute addresses for both the exception location and the fixup, use offsets relative to the exception table entry values. Not only does this cut the size of the exception table in half, it is also a prerequisite for KASLR, since absolute exception table entries are subject to dynamic relocation, which is incompatible with the sorting of the exception table that occurs at build time. This patch also introduces the _ASM_EXTABLE preprocessor macro (which exists on x86 as well) and its _asm_extable assembly counterpart, as shorthands to emit exception table entries. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-24arm64: make asm/elf.h available to asm filesArd Biesheuvel1-9/+13
This reshuffles some code in asm/elf.h and puts a #ifndef __ASSEMBLY__ around its C definitions so that the CPP defines can be used in asm source files as well. Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-24arm64: avoid R_AARCH64_ABS64 relocations for Image header fieldsArd Biesheuvel1-0/+11
Unfortunately, the current way of using the linker to emit build time constants into the Image header will no longer work once we switch to the use of PIE executables. The reason is that such constants are emitted into the binary using R_AARCH64_ABS64 relocations, which are resolved at runtime, not at build time, and the places targeted by those relocations will contain zeroes before that. So refactor the endian swapping linker script constant generation code so that it emits the upper and lower 32-bit words separately. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-24arm64: add support for module PLTsArd Biesheuvel1-0/+11
This adds support for emitting PLTs at module load time for relative branches that are out of range. This is a prerequisite for KASLR, which may place the kernel and the modules anywhere in the vmalloc area, making it more likely that branch target offsets exceed the maximum range of +/- 128 MB. In this version, I removed the distinction between relocations against .init executable sections and ordinary executable sections. The reason is that it is hardly worth the trouble, given that .init.text usually does not contain that many far branches, and this version now only reserves PLT entry space for jump and call relocations against undefined symbols (since symbols defined in the same module can be assumed to be within +/- 128 MB) For example, the mac80211.ko module (which is fairly sizable at ~400 KB) built with -mcmodel=large gives the following relocation counts: relocs branches unique !local .text 3925 3347 518 219 .init.text 11 8 7 1 .exit.text 4 4 4 1 .text.unlikely 81 67 36 17 ('unique' means branches to unique type/symbol/addend combos, of which !local is the subset referring to undefined symbols) IOW, we are only emitting a single PLT entry for the .init sections, and we are better off just adding it to the core PLT section instead. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-23arm64: move brk immediate argument definitions to separate headerArd Biesheuvel3-14/+27
Instead of reversing the header dependency between asm/bug.h and asm/debug-monitors.h, split off the brk instruction immediate value defines into a new header asm/brk-imm.h, and include it from both. This solves the circular dependency issue that prevents BUG() from being used in some header files, and keeps the definitions together. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-23arm64: mm: use bit ops rather than arithmetic in pa/va translationsArd Biesheuvel1-3/+4
Since PAGE_OFFSET is chosen such that it cuts the kernel VA space right in half, and since the size of the kernel VA space itself is always a power of 2, we can treat PAGE_OFFSET as a bitmask and replace the additions/subtractions with 'or' and 'and-not' operations. For the comparison against PAGE_OFFSET, a mov/cmp/branch sequence ends up getting replaced with a single tbz instruction. For the additions and subtractions, we save a mov instruction since the mask is folded into the instruction's immediate field. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-23arm64: mm: only perform memstart_addr sanity check if DEBUG_VMArd Biesheuvel1-1/+3
Checking whether memstart_addr has been assigned every time it is referenced adds a branch instruction that may hurt performance if the reference in question occurs on a hot path. So only perform the check if CONFIG_DEBUG_VM=y. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [catalin.marinas@arm.com: replaced #ifdef with VM_BUG_ON] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-22asm-generic: Consolidate mark_rodata_ro()Kees Cook1-4/+0
Instead of defining mark_rodata_ro() in each architecture, consolidate it. Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Gross <agross@codeaurora.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Ashok Kumar <ashoks@broadcom.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Brown <david.brown@linaro.org> Cc: David Hildenbrand <dahi@linux.vnet.ibm.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Emese Revfy <re.emese@gmail.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Helge Deller <deller@gmx.de> Cc: James E.J. Bottomley <jejb@parisc-linux.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathias Krause <minipli@googlemail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: PaX Team <pageexec@freemail.hu> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Stephen Boyd <sboyd@codeaurora.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Cc: kernel-hardening@lists.openwall.com Cc: linux-arch <linux-arch@vger.kernel.org> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Cc: linux-parisc@vger.kernel.org Link: http://lkml.kernel.org/r/1455748879-21872-2-git-send-email-keescook@chromium.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-20arm64: cputype info for Broadcom VulcanJayachandran C1-0/+3
Add Broadcom Vulcan implementor ID and part ID in cputype.h. This is to document the values. Signed-off-by: Jayachandran C <jchandra@broadcom.com> Acked-by: Will Deacon <will.deacon@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
2016-02-18arm64: allow kernel Image to be loaded anywhere in physical memoryArd Biesheuvel4-24/+29
This relaxes the kernel Image placement requirements, so that it may be placed at any 2 MB aligned offset in physical memory. This is accomplished by ignoring PHYS_OFFSET when installing memblocks, and accounting for the apparent virtual offset of the kernel Image. As a result, virtual address references below PAGE_OFFSET are correctly mapped onto physical references into the kernel Image regardless of where it sits in memory. Special care needs to be taken for dealing with memory limits passed via mem=, since the generic implementation clips memory top down, which may clip the kernel image itself if it is loaded high up in memory. To deal with this case, we simply add back the memory covering the kernel image, which may result in more memory to be retained than was passed as a mem= parameter. Since mem= should not be considered a production feature, a panic notifier handler is installed that dumps the memory limit at panic time if one was set. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-18arm64: defer __va translation of initrd_start and initrd_endArd Biesheuvel1-0/+8
Before deferring the assignment of memstart_addr in a subsequent patch, to the moment where all memory has been discovered and possibly clipped based on the size of the linear region and the presence of a mem= command line parameter, we need to ensure that memstart_addr is not used to perform __va translations before it is assigned. One such use is in the generic early DT discovery of the initrd location, which is recorded as a virtual address in the globals initrd_start and initrd_end. So wire up the generic support to declare the initrd addresses, and implement it without __va() translations, and perform the translation after memstart_addr has been assigned. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-18arm64: move kernel image to base of vmalloc areaArd Biesheuvel3-15/+18
This moves the module area to right before the vmalloc area, and moves the kernel image to the base of the vmalloc area. This is an intermediate step towards implementing KASLR, which allows the kernel image to be located anywhere in the vmalloc area. Since other subsystems such as hibernate may still need to refer to the kernel text or data segments via their linears addresses, both are mapped in the linear region as well. The linear alias of the text region is mapped read-only/non-executable to prevent inadvertent modification or execution. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-18arm64: kvm: deal with kernel symbols outside of linear mappingArd Biesheuvel2-3/+22
KVM on arm64 uses a fixed offset between the linear mapping at EL1 and the HYP mapping at EL2. Before we can move the kernel virtual mapping out of the linear mapping, we have to make sure that references to kernel symbols that are accessed via the HYP mapping are translated to their linear equivalent. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-18arm64: pgtable: implement static [pte|pmd|pud]_offset variantsArd Biesheuvel1-0/+13
The page table accessors pte_offset(), pud_offset() and pmd_offset() rely on __va translations, so they can only be used after the linear mapping has been installed. For the early fixmap and kasan init routines, whose page tables are allocated statically in the kernel image, these functions will return bogus values. So implement pte_offset_kimg(), pmd_offset_kimg() and pud_offset_kimg(), which can be used instead before any page tables have been allocated dynamically. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-18arm64: introduce KIMAGE_VADDR as the virtual base of the kernel regionArd Biesheuvel1-2/+8
This introduces the preprocessor symbol KIMAGE_VADDR which will serve as the symbolic virtual base of the kernel region, i.e., the kernel's virtual offset will be KIMAGE_VADDR + TEXT_OFFSET. For now, we define it as being equal to PAGE_OFFSET, but in the future, it will be moved below it once we move the kernel virtual mapping out of the linear mapping. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-18arm64: add support for ioremap() block mappingsArd Biesheuvel1-0/+6
This wires up the existing generic huge-vmap feature, which allows ioremap() to use PMD or PUD sized block mappings. It also adds support to the unmap path for dealing with block mappings, which will allow us to unmap the __init region using unmap_kernel_range() in a subsequent patch. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-18arm64: prevent potential circular header dependencies in asm/bug.hArd Biesheuvel2-2/+2
Currently, using BUG_ON() in header files is cumbersome, due to the fact that asm/bug.h transitively includes a lot of other header files, resulting in the actual BUG_ON() invocation appearing before its definition in the preprocessor input. So let's reverse the #include dependency between asm/bug.h and asm/debug-monitors.h, by moving the definition of BUG_BRK_IMM from the latter to the former. Also fix up one user of asm/debug-monitors.h which relied on a transitive include. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-18arm64: Remove the get_thread_info() functionCatalin Marinas1-6/+0
This function was introduced by previous commits implementing UAO. However, it can be replaced with task_thread_info() in uao_thread_switch() or get_fs() in do_page_fault() (the latter being called only on the current context, so no need for using the saved pt_regs). Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-18arm64: kernel: Don't toggle PAN on systems with UAOJames Morse2-5/+6
If a CPU supports both Privileged Access Never (PAN) and User Access Override (UAO), we don't need to disable/re-enable PAN round all copy_to_user() like calls. UAO alternatives cause these calls to use the 'unprivileged' load/store instructions, which are overridden to be the privileged kind when fs==KERNEL_DS. This patch changes the copy_to_user() calls to have their PAN toggling depend on a new composite 'feature' ARM64_ALT_PAN_NOT_UAO. If both features are detected, PAN will be enabled, but the copy_to_user() alternatives will not be applied. This means PAN will be enabled all the time for these functions. If only PAN is detected, the toggling will be enabled as normal. This will save the time taken to disable/re-enable PAN, and allow us to catch copy_to_user() accesses that occur with fs==KERNEL_DS. Futex and swp-emulation code continue to hang their PAN toggling code on ARM64_HAS_PAN. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-18arm64: kernel: Add support for User Access OverrideJames Morse6-13/+116
'User Access Override' is a new ARMv8.2 feature which allows the unprivileged load and store instructions to be overridden to behave in the normal way. This patch converts {get,put}_user() and friends to use ldtr*/sttr* instructions - so that they can only access EL0 memory, then enables UAO when fs==KERNEL_DS so that these functions can access kernel memory. This allows user space's read/write permissions to be checked against the page tables, instead of testing addr<USER_DS, then using the kernel's read/write permissions. Signed-off-by: James Morse <james.morse@arm.com> [catalin.marinas@arm.com: move uao_thread_switch() above dsb()] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-18arm64: add ARMv8.2 id_aa64mmfr2 boiler plateJames Morse2-0/+5
ARMv8.2 adds a new feature register id_aa64mmfr2. This patch adds the cpu feature boiler plate used by the actual features in later patches. Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-18arm64: cpufeature: Change read_cpuid() to use sysreg's mrs_s macroJames Morse2-10/+12
Older assemblers may not have support for newer feature registers. To get round this, sysreg.h provides a 'mrs_s' macro that takes a register encoding and generates the raw instruction. Change read_cpuid() to use mrs_s in all cases so that new registers don't have to be a special case. Including sysreg.h means we need to move the include and definition of read_cpuid() after the #ifndef __ASSEMBLY__ to avoid syntax errors in vmlinux.lds. Signed-off-by: James Morse <james.morse@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-16Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds1-2/+0
Pull ARM KVM fixes from Paolo Bonzini: - Fix for an unpleasant crash when the VM is created without a timer - Allow HYP mode to access the full PA space, and not only 40bit * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: arm64: KVM: Configure TCR_EL2.PS at runtime KVM: arm/arm64: Fix reference to uninitialised VGIC
2016-02-16arm64: use local label prefixes for __reg_num symbolsArd Biesheuvel1-8/+8
The __reg_num_xNN symbols that are used to implement the msr_s and mrs_s macros are recorded in the ELF metadata of each object file. This does not affect the size of the final binary, but it does clutter the output of tools like readelf, i.e., $ readelf -a vmlinux |grep -c __reg_num_x 50976 So let's use symbols with the .L prefix, these are strictly local, and don't end up in the object files. $ readelf -a vmlinux |grep -c __reg_num_x 0 Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-16Merge tag 'kvm-arm-for-4.5-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-masterPaolo Bonzini1-2/+0
KVM/ARM fixes for 4.5-rc4 - Fix for an unpleasant crash when the VM is created without a timer - Allow HYP mode to access the full PA space, and not only 40bit
2016-02-16arm64: prefetch: add missing #include for spin_lock_prefetchWill Deacon1-0/+1
As of 52e662326e1e ("arm64: prefetch: don't provide spin_lock_prefetch with LSE"), spin_lock_prefetch is patched at runtime when the LSE atomics are in use. This relies on the ARM64_LSE_ATOMIC_INSN macro to drive the alternatives framework, but that macro is only available via asm/lse.h, which isn't explicitly included in processor.h. Consequently, drivers can run into build failures such as: In file included from include/linux/prefetch.h:14:0, from drivers/net/ethernet/intel/i40e/i40e_txrx.c:27: arch/arm64/include/asm/processor.h: In function 'spin_lock_prefetch': arch/arm64/include/asm/processor.h:183:15: error: expected string literal before 'ARM64_LSE_ATOMIC_INSN' asm volatile(ARM64_LSE_ATOMIC_INSN( This patch add the missing include and gets things building again. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-16arm64: prefetch: add alternative pattern for CPUs without a prefetcherWill Deacon2-2/+18
Most CPUs have a hardware prefetcher which generally performs better without explicit prefetch instructions issued by software, however some CPUs (e.g. Cavium ThunderX) rely solely on explicit prefetch instructions. This patch adds an alternative pattern (ARM64_HAS_NO_HW_PREFETCH) to allow our library code to make use of explicit prefetch instructions during things like copy routines only when the CPU does not have the capability to perform the prefetching itself. Signed-off-by: Will Deacon <will.deacon@arm.com> Tested-by: Andrew Pinski <apinski@cavium.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-16arm64: prefetch: don't provide spin_lock_prefetch with LSEWill Deacon1-2/+5
The LSE atomics rely on us not dirtying data at L1 if we can avoid it, otherwise many of the potential scalability benefits are lost. This patch replaces spin_lock_prefetch with a nop when the LSE atomics are in use, so that users don't shoot themselves in the foot by causing needless coherence traffic at L1. Signed-off-by: Will Deacon <will.deacon@arm.com> Tested-by: Andrew Pinski <apinski@cavium.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-16arm64: kernel: implement ACPI parking protocolLorenzo Pieralisi3-2/+28
The SBBR and ACPI specifications allow ACPI based systems that do not implement PSCI (eg systems with no EL3) to boot through the ACPI parking protocol specification[1]. This patch implements the ACPI parking protocol CPU operations, and adds code that eases parsing the parking protocol data structures to the ARM64 SMP initializion carried out at the same time as cpus enumeration. To wake-up the CPUs from the parked state, this patch implements a wakeup IPI for ARM64 (ie arch_send_wakeup_ipi_mask()) that mirrors the ARM one, so that a specific IPI is sent for wake-up purpose in order to distinguish it from other IPI sources. Given the current ACPI MADT parsing API, the patch implements a glue layer that helps passing MADT GICC data structure from SMP initialization code to the parking protocol implementation somewhat overriding the CPU operations interfaces. This to avoid creating a completely trasparent DT/ACPI CPU operations layer that would require creating opaque structure handling for CPUs data (DT represents CPU through DT nodes, ACPI through static MADT table entries), which seems overkill given that ACPI on ARM64 mandates only two booting protocols (PSCI and parking protocol), so there is no need for further protocol additions. Based on the original work by Mark Salter <msalter@redhat.com> [1] https://acpica.org/sites/acpica/files/MP%20Startup%20for%20ARM%20platforms.docx Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Tested-by: Loc Ho <lho@apm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Hanjun Guo <hanjun.guo@linaro.org> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mark Salter <msalter@redhat.com> Cc: Al Stone <ahs3@redhat.com> [catalin.marinas@arm.com: Added WARN_ONCE(!acpi_parking_protocol_valid() on the IPI] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-16arm64: mm: create new fine-grained mappings at bootMark Rutland1-0/+3
At boot we may change the granularity of the tables mapping the kernel (by splitting or making sections). This may happen when we create the linear mapping (in __map_memblock), or at any point we try to apply fine-grained permissions to the kernel (e.g. fixup_executable, mark_rodata_ro, fixup_init). Changing the active page tables in this manner may result in multiple entries for the same address being allocated into TLBs, risking problems such as TLB conflict aborts or issues derived from the amalgamation of TLB entries. Generally, a break-before-make (BBM) approach is necessary to avoid conflicts, but we cannot do this for the kernel tables as it risks unmapping text or data being used to do so. Instead, we can create a new set of tables from scratch in the safety of the existing mappings, and subsequently migrate over to these using the new cpu_replace_ttbr1 helper, which avoids the two sets of tables being active simultaneously. To avoid issues when we later modify permissions of the page tables (e.g. in fixup_init), we must create the page tables at a granularity such that later modification does not result in splitting of tables. This patch applies this strategy, creating a new set of fine-grained page tables from scratch, and safely migrating to them. The existing fixmap and kasan shadow page tables are reused in the new fine-grained tables. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Jeremy Linton <jeremy.linton@arm.com> Cc: Laura Abbott <labbott@fedoraproject.org> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-16arm64: mm: add functions to walk tables in fixmapMark Rutland2-0/+36
As a preparatory step to allow us to allocate early page tables from unmapped memory using memblock_alloc, add new p??_{set,clear}_fixmap* functions which can be used to walk page tables outside of the linear mapping by using fixmap slots. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Jeremy Linton <jeremy.linton@arm.com> Cc: Laura Abbott <labbott@fedoraproject.org> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-16arm64: mm: add __{pud,pgd}_populateMark Rutland1-4/+22
We currently have __pmd_populate for creating a pmd table entry given the physical address of a pte, but don't have equivalents for the pud or pgd levels of table. To enable us to manipulate tables which are mapped outside of the linear mapping (where we have a PA, but not a linear map VA), it is useful to have these functions. This patch adds __{pud,pgd}_populate. As these should not be called when the kernel uses folded {pmd,pud}s, in these cases they expand to BUILD_BUG(). So long as the appropriate checks are made on the {pud,pgd} entry prior to attempting population, these should be optimized out at compile time. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Jeremy Linton <jeremy.linton@arm.com> Cc: Laura Abbott <labbott@fedoraproject.org> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-16arm64: mm: add functions to walk page tables by PAMark Rutland1-16/+23
To allow us to walk tables allocated into the fixmap, we need to acquire the physical address of a page, rather than the virtual address in the linear map. This patch adds new p??_page_paddr and p??_offset_phys functions to acquire the physical address of a next-level table, and changes p??_offset* into macros which simply convert this to a linear map VA. This renders p??_page_vaddr unused, and hence they are removed. At the pgd level, a new pgd_offset_raw function is added to find the relevant PGD entry given the base of a PGD and a virtual address. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Jeremy Linton <jeremy.linton@arm.com> Cc: Laura Abbott <labbott@fedoraproject.org> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-16arm64: mm: move pte_* macrosMark Rutland1-10/+10
For pmd, pud, and pgd levels of table, functions including p?d_index and p?d_offset are defined after the p?d_page_vaddr function for the immediately higher level of table. The pte functions however are defined much earlier, even though several rely on the later definition of pmd_page_vaddr. While this isn't currently a problem as these are macros, it prevents the logical grouping of later C functions (which cannot rely on prototypes for functions not yet defined). Move these definitions after pmd_page_vaddr, for consistency with the placement of these functions for other levels of table. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Jeremy Linton <jeremy.linton@arm.com> Cc: Laura Abbott <labbott@fedoraproject.org> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-16arm64: mm: add code to safely replace TTBR1_EL1Mark Rutland1-0/+19
If page tables are modified without suitable TLB maintenance, the ARM architecture permits multiple TLB entries to be allocated for the same VA. When this occurs, it is permitted that TLB conflict aborts are raised in response to synchronous data/instruction accesses, and/or and amalgamation of the TLB entries may be used as a result of a TLB lookup. The presence of conflicting TLB entries may result in a variety of behaviours detrimental to the system (e.g. erroneous physical addresses may be used by I-cache fetches and/or page table walks). Some of these cases may result in unexpected changes of hardware state, and/or result in the (asynchronous) delivery of SError. To avoid these issues, we must avoid situations where conflicting entries may be allocated into TLBs. For user and module mappings we can follow a strict break-before-make approach, but this cannot work for modifications to the swapper page tables that cover the kernel text and data. Instead, this patch adds code which is intended to be executed from the idmap, which can safely unmap the swapper page tables as it only requires the idmap to be active. This enables us to uninstall the active TTBR1_EL1 entry, invalidate TLBs, then install a new TTBR1_EL1 entry without potentially unmapping code or data required for the sequence. This avoids the risk of conflict, but requires that updates are staged in a copy of the swapper page tables prior to being installed. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Jeremy Linton <jeremy.linton@arm.com> Cc: Laura Abbott <labbott@fedoraproject.org> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-16arm64: add function to install the idmapMark Rutland1-2/+14
In some cases (e.g. when making invasive changes to the kernel page tables) we will need to execute code from the idmap. Add a new helper which may be used to install the idmap, complementing the existing cpu_uninstall_idmap. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Jeremy Linton <jeremy.linton@arm.com> Cc: Laura Abbott <labbott@fedoraproject.org> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-16arm64: unify idmap removalMark Rutland1-0/+25
We currently open-code the removal of the idmap and restoration of the current task's MMU state in a few places. Before introducing yet more copies of this sequence, unify these to call a new helper, cpu_uninstall_idmap. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Jeremy Linton <jeremy.linton@arm.com> Cc: Laura Abbott <labbott@fedoraproject.org> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-16arm64: mm: place empty_zero_page in bssMark Rutland2-3/+3
Currently the zero page is set up in paging_init, and thus we cannot use the zero page earlier. We use the zero page as a reserved TTBR value from which no TLB entries may be allocated (e.g. when uninstalling the idmap). To enable such usage earlier (as may be required for invasive changes to the kernel page tables), and to minimise the time that the idmap is active, we need to be able to use the zero page before paging_init. This patch follows the example set by x86, by allocating the zero page at compile time, in .bss. This means that the zero page itself is available immediately upon entry to start_kernel (as we zero .bss before this), and also means that the zero page takes up no space in the raw Image binary. The associated struct page is allocated in bootmem_init, and remains unavailable until this time. Outside of arch code, the only users of empty_zero_page assume that the empty_zero_page symbol refers to the zeroed memory itself, and that ZERO_PAGE(x) must be used to acquire the associated struct page, following the example of x86. This patch also brings arm64 inline with these assumptions. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Jeremy Linton <jeremy.linton@arm.com> Cc: Laura Abbott <labbott@fedoraproject.org> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-14Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-0/+1
Pull irqchip fixes from Thomas Gleixner: "Another set of ARM SoC related irqchip fixes: - Plug a memory leak in gicv3-its - Limit features to the root gic interrupt controller - Add a missing barrier in the gic-v3 IAR access - Another compile test fix for sun4i" * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: irqchip/gic-v3: Make sure read from ICC_IAR1_EL1 is visible on redestributor irqchip/gic: Only set the EOImodeNS bit for the root controller irqchip/gic: Only populate set_affinity for the root controller irqchip/gicv3-its: Fix memory leak in its_free_tables() irqchip/sun4i: Fix compilation outside of arch/arm
2016-02-11arm64: KVM: Configure TCR_EL2.PS at runtimeTirumalesh Chalamarla1-2/+0
Setting TCR_EL2.PS to 40 bits is wrong on systems with less that less than 40 bits of physical addresses. and breaks KVM on systems where the RAM is above 40 bits. This patch uses ID_AA64MMFR0_EL1.PARange to set TCR_EL2.PS dynamically, just like we already do for VTCR_EL2.PS. [Marc: rewrote commit message, patch tidy up] Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Tirumalesh Chalamarla <tchalamarla@caviumnetworks.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-11irqchip/gic-v3: Make sure read from ICC_IAR1_EL1 is visible on redestributorTirumalesh Chalamarla1-0/+1
The ARM GICv3 specification mentions the need for dsb after a read from the ICC_IAR1_EL1 register: 4.1.1 Physical CPU Interface: The effects of reading ICC_IAR0_EL1 and ICC_IAR1_EL1 on the state of a returned INTID are not guaranteed to be visible until after the execution of a DSB. Not having this could result in missed interrupts, so let's add the required barrier. [Marc: fixed commit message] Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Tirumalesh Chalamarla <tchalamarla@caviumnetworks.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-08Merge tag 'kvm-arm-for-4.5-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-masterPaolo Bonzini2-2/+7
KVM/ARM fixes for v4.5-rc2 A few random fixes, mostly coming from the PMU work by Shannon: - fix for injecting faults coming from the guest's userspace - cleanup for our CPTR_EL2 accessors (reserved bits) - fix for a bug impacting perf (user/kernel discrimination) - fix for a 32bit sysreg handling bug
2016-02-05ARM64: PCI: Remove generated include of asm-generic/pci-bridge.hBjorn Helgaas1-3/+0
arm64 generates asm/pci-bridge.h, which merely includes the now-empty asm-generic/pci-bridge.h. Stop generating asm/pci-bridge.h, and stop including it. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Will Deacon <will.deacon@arm.com>
2016-02-05PCI: Remove includes of empty asm-generic/pci-bridge.hBjorn Helgaas1-1/+0
include/asm-generic/pci-bridge.h is now empty, so remove every #include of it. Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Will Deacon <will.deacon@arm.com> (arm64)
2016-02-03arm64: asm: Explicitly include linux/personality.h in asm/page.hMark Brown1-0/+1
asm/page.h uses READ_IMPLIES_EXEC from linux/personality.h but does not explicitly include it causing build failures in -next where whatever was causing it to be implicitly included has changed to remove that inclusion. Add an explicit inclusion to fix this. Signed-off-by: Mark Brown <broonie@kernel.org> [will: moved #include inside #ifndef __ASSEMBLY__ block] Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-02-02arm64: futex.h: Add missing PAN togglingJames Morse1-0/+2
futex.h's futex_atomic_cmpxchg_inatomic() does not use the __futex_atomic_op() macro and needs its own PAN toggling. This was missed when the feature was implemented. Fixes: 338d4f49d6f ("arm64: kernel: Add support for Privileged Access Never") Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-01-25arm64: Honour !PTE_WRITE in set_pte_at() for kernel mappingsCatalin Marinas1-11/+10
Currently, set_pte_at() only checks the software PTE_WRITE bit for user mappings when it sets or clears the hardware PTE_RDONLY accordingly. The kernel ptes are written directly without any modification, relying solely on the protection bits in macros like PAGE_KERNEL. However, modifying kernel pte attributes via pte_wrprotect() would be ignored by set_pte_at(). Since pte_wrprotect() does not set PTE_RDONLY (it only clears PTE_WRITE), the new permission is not taken into account. This patch changes set_pte_at() to adjust the read-only permission for kernel ptes as well. As a side effect, existing PROT_* definitions used for kernel ioremap*() need to include PTE_DIRTY | PTE_WRITE. (additionally, white space fix for PTE_KERNEL_ROX) Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reported-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>