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2015-05-28arm,arm64/xen: move Xen initialization earlierStefano Stabellini1-0/+2
Currently, Xen is initialized/discovered in an initcall. This doesn't allow us to support earlyprintk or choosing the preferred console when running on Xen. The current function xen_guest_init is now split in 2 parts: - xen_early_init: Check if there is a Xen node in the device tree and setup domain type - xen_guest_init: Retrieve the information from the device node and initialize Xen (grant table, shared page...) The former is called in setup_arch, while the latter is an initcall. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Julien Grall <julien.grall@linaro.org> Acked-by: Ian Campbell <ian.campbell@citrix.com> Acked-by: Will Deacon <will.deacon@arm.com>
2015-05-19ARM64: kernel: unify ACPI and DT cpus initializationLorenzo Pieralisi1-5/+2
The code that initializes cpus on arm64 is currently split in two different code paths that carry out DT and ACPI cpus initialization. Most of the code executing SMP initialization is common and should be merged to reduce discrepancies between ACPI and DT initialization and to have code initializing cpus in a single common place in the kernel. This patch refactors arm64 SMP cpus initialization code to merge ACPI and DT boot paths in a common file and to create sanity checks that can be reused by both boot methods. Current code assumes PSCI is the only available boot method when arm64 boots with ACPI; this can be easily extended if/when the ACPI parking protocol is merged into the kernel. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Acked-by: Hanjun Guo <hanjun.guo@linaro.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Hanjun Guo <hanjun.guo@linaro.org> Tested-by: Mark Rutland <mark.rutland@arm.com> [DT] Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-04-24Merge tag 'arm64-upstream' of ↵Linus Torvalds1-5/+16
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull initial ACPI support for arm64 from Will Deacon: "This series introduces preliminary ACPI 5.1 support to the arm64 kernel using the "hardware reduced" profile. We don't support any peripherals yet, so it's fairly limited in scope: - MEMORY init (UEFI) - ACPI discovery (RSDP via UEFI) - CPU init (FADT) - GIC init (MADT) - SMP boot (MADT + PSCI) - ACPI Kconfig options (dependent on EXPERT) ACPI for arm64 has been in development for a while now and hardware has been available that can boot with either FDT or ACPI tables. This has been made possible by both changes to the ACPI spec to cater for ARM-based machines (known as "hardware-reduced" in ACPI parlance) but also a Linaro-driven effort to get this supported on top of the Linux kernel. This pull request is the result of that work. These changes allow us to initialise the CPUs, interrupt controller, and timers via ACPI tables, with memory information and cmdline coming from EFI. We don't support a hybrid ACPI/FDT scheme. Of course, there is still plenty of work to do (a serial console would be nice!) but I expect that to happen on a per-driver basis after this core series has been merged. Anyway, the diff stat here is fairly horrible, but splitting this up and merging it via all the different subsystems would have been extremely painful. Instead, we've got all the relevant Acks in place and I've not seen anything other than trivial (Kconfig) conflicts in -next (for completeness, I've included my resolution below). Nearly half of the insertions fall under Documentation/. So, we'll see how this goes. Right now, it all depends on EXPERT and I fully expect people to use FDT by default for the immediate future" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (31 commits) ARM64 / ACPI: make acpi_map_gic_cpu_interface() as void function ARM64 / ACPI: Ignore the return error value of acpi_map_gic_cpu_interface() ARM64 / ACPI: fix usage of acpi_map_gic_cpu_interface ARM64: kernel: acpi: honour acpi=force command line parameter ARM64: kernel: acpi: refactor ACPI tables init and checks ARM64: kernel: psci: let ACPI probe PSCI version ARM64: kernel: psci: factor out probe function ACPI: move arm64 GSI IRQ model to generic GSI IRQ layer ARM64 / ACPI: Don't unflatten device tree if acpi=force is passed ARM64 / ACPI: additions of ACPI documentation for arm64 Documentation: ACPI for ARM64 ARM64 / ACPI: Enable ARM64 in Kconfig XEN / ACPI: Make XEN ACPI depend on X86 ARM64 / ACPI: Select ACPI_REDUCED_HARDWARE_ONLY if ACPI is enabled on ARM64 clocksource / arch_timer: Parse GTDT to initialize arch timer irqchip: Add GICv2 specific ACPI boot support ARM64 / ACPI: Introduce ACPI_IRQ_MODEL_GIC and register device's gsi ACPI / processor: Make it possible to get CPU hardware ID via GICC ACPI / processor: Introduce phys_cpuid_t for CPU hardware ID ARM64 / ACPI: Parse MADT for SMP initialization ...
2015-03-26ARM64: kernel: acpi: honour acpi=force command line parameterLorenzo Pieralisi1-1/+1
If acpi=force is passed on the command line, it forces ACPI to be the only available boot method, hence it must be left enabled even if the initialization and sanity checks on ACPI tables fails. This patch refactors ACPI initialization to prevent disabling ACPI if acpi=force is passed on the command line. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Hanjun Guo <hanjun.guo@linaro.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Hanjun Guo <hanjun.guo@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-03-26ARM64 / ACPI: Don't unflatten device tree if acpi=force is passedHanjun Guo1-1/+1
Since the policy is that once we pass acpi=force in the early param, we will not unflatten device tree even if ACPI is disabled in ACPI table init fails, so fix the code by comparinging both acpi_disabled and param_acpi_force before the device tree is unflattened. CC: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-03-25ARM64 / ACPI: Parse MADT for SMP initializationHanjun Guo1-2/+5
MADT contains the information for MPIDR which is essential for SMP initialization, parse the GIC cpu interface structures to get the MPIDR value and map it to cpu_logical_map(), and add enabled cpu with valid MPIDR into cpu_possible_map. ACPI 5.1 only has two explicit methods to boot up SMP, PSCI and Parking protocol, but the Parking protocol is only specified for ARMv7 now, so make PSCI as the only way for the SMP boot protocol before some updates for the ACPI spec or the Parking protocol spec. Parking protocol patches for SMP boot will be sent to upstream when the new version of Parking protocol is ready. CC: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> CC: Catalin Marinas <catalin.marinas@arm.com> CC: Will Deacon <will.deacon@arm.com> CC: Mark Rutland <mark.rutland@arm.com> Tested-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com> Tested-by: Yijing Wang <wangyijing@huawei.com> Tested-by: Mark Langsdorf <mlangsdo@redhat.com> Tested-by: Jon Masters <jcm@redhat.com> Tested-by: Timur Tabi <timur@codeaurora.org> Tested-by: Robert Richter <rrichter@cavium.com> Acked-by: Robert Richter <rrichter@cavium.com> Acked-by: Olof Johansson <olof@lixom.net> Reviewed-by: Grant Likely <grant.likely@linaro.org> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Tomasz Nowicki <tomasz.nowicki@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-03-25ARM64 / ACPI: Get PSCI flags in FADT for PSCI initGraeme Gregory1-3/+5
There are two flags: PSCI_COMPLIANT and PSCI_USE_HVC. When set, the former signals to the OS that the firmware is PSCI compliant. The latter selects the appropriate conduit for PSCI calls by toggling between Hypervisor Calls (HVC) and Secure Monitor Calls (SMC). FADT table contains such information in ACPI 5.1, FADT table was parsed in ACPI table init and copy to struct acpi_gbl_FADT, so use the flags in struct acpi_gbl_FADT for PSCI init. Since ACPI 5.1 doesn't support self defined PSCI function IDs, which means that only PSCI 0.2+ is supported in ACPI. CC: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> CC: Catalin Marinas <catalin.marinas@arm.com> CC: Will Deacon <will.deacon@arm.com> Tested-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com> Tested-by: Yijing Wang <wangyijing@huawei.com> Tested-by: Mark Langsdorf <mlangsdo@redhat.com> Tested-by: Jon Masters <jcm@redhat.com> Tested-by: Timur Tabi <timur@codeaurora.org> Tested-by: Robert Richter <rrichter@cavium.com> Acked-by: Robert Richter <rrichter@cavium.com> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Grant Likely <grant.likely@linaro.org> Signed-off-by: Graeme Gregory <graeme.gregory@linaro.org> Signed-off-by: Tomasz Nowicki <tomasz.nowicki@linaro.org> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-03-25ARM64 / ACPI: If we chose to boot from acpi then disable FDTGraeme Gregory1-1/+2
If the early boot methods of acpi are happy that we have valid ACPI tables and acpi=force has been passed, then do not unflat devicetree effectively disabling further hardware probing from DT. CC: Catalin Marinas <catalin.marinas@arm.com> CC: Will Deacon <will.deacon@arm.com> Tested-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com> Tested-by: Yijing Wang <wangyijing@huawei.com> Tested-by: Mark Langsdorf <mlangsdo@redhat.com> Tested-by: Jon Masters <jcm@redhat.com> Tested-by: Timur Tabi <timur@codeaurora.org> Tested-by: Robert Richter <rrichter@cavium.com> Acked-by: Robert Richter <rrichter@cavium.com> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Grant Likely <grant.likely@linaro.org> Signed-off-by: Graeme Gregory <graeme.gregory@linaro.org> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-03-25ARM64 / ACPI: Get RSDP and ACPI boot-time tablesAl Stone1-0/+5
As we want to get ACPI tables to parse and then use the information for system initialization, we should get the RSDP (Root System Description Pointer) first, it then locates Extended Root Description Table (XSDT) which contains all the 64-bit physical address that pointer to other boot-time tables. Introduce acpi.c and its related head file in this patch to provide fundamental needs of extern variables and functions for ACPI core, and then get boot-time tables as needed. - asm/acenv.h for arch specific ACPICA environments and implementation, It is needed unconditionally by ACPI core; - asm/acpi.h for arch specific variables and functions needed by ACPI driver core; - acpi.c for ARM64 related ACPI implementation for ACPI driver core; acpi_boot_table_init() is introduced to get RSDP and boot-time tables, it will be called in setup_arch() before paging_init(), so we should use eary_memremap() mechanism here to get the RSDP and all the table pointers. FADT Major.Minor version was introduced in ACPI 5.1, it is the same as ACPI version. In ACPI 5.1, some major gaps are fixed for ARM, such as updates in MADT table for GIC and SMP init, without those updates, we can not get the MPIDR for SMP init, and GICv2/3 related init information, so we can't boot arm64 ACPI properly with table versions predating 5.1. If firmware provides ACPI tables with ACPI version less than 5.1, OS has no way to retrieve the configuration data that is necessary to init SMP boot protocol and the GIC properly, so disable ACPI if we get an FADT table with version less that 5.1 when acpi_boot_table_init() called. CC: Catalin Marinas <catalin.marinas@arm.com> CC: Will Deacon <will.deacon@arm.com> CC: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Tested-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com> Tested-by: Yijing Wang <wangyijing@huawei.com> Tested-by: Mark Langsdorf <mlangsdo@redhat.com> Tested-by: Jon Masters <jcm@redhat.com> Tested-by: Timur Tabi <timur@codeaurora.org> Tested-by: Robert Richter <rrichter@cavium.com> Acked-by: Robert Richter <rrichter@cavium.com> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Grant Likely <grant.likely@linaro.org> Signed-off-by: Al Stone <al.stone@linaro.org> Signed-off-by: Graeme Gregory <graeme.gregory@linaro.org> Signed-off-by: Tomasz Nowicki <tomasz.nowicki@linaro.org> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-03-19arm64: enforce x1|x2|x3 == 0 upon kernel entry as per boot protocolArd Biesheuvel1-0/+11
According to the arm64 boot protocol, registers x1 to x3 should be zero upon kernel entry, and non-zero values are reserved for future use. This future use is going to be problematic if we never enforce the current rules, so start enforcing them now, by emitting a warning if non-zero values are detected. Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-03-19arm64: remove processor_idArd Biesheuvel1-3/+0
The global processor_id is assigned the MIDR_EL1 value of the boot CPU in the early init code, but is never referenced afterwards. As the relevance of the MIDR_EL1 value of the boot CPU is debatable anyway, especially under big.LITTLE, let's remove it before anyone starts using it. Tested-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-03-19arm64: Get rid of struct cpu_tableMarc Zyngier1-14/+2
struct cpu_table is an artifact left from the (very) early days of the arm64 port, and its only real use is to allow the most beautiful "AArch64 Processor" string to be displayed at boot time. Really? Yes, really. Let's get rid of it. In order to avoid another BogoMips-gate, the aforementioned string is preserved. Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-03-17arm64: log CPU boot modesMark Rutland1-0/+13
We currently don't log the boot mode for arm64 as we do for arm, and without KVM the user is provided with no indication as to which mode(s) CPUs were booted in, which can seriously hinder debugging in some cases. Add logging to the boot path once all CPUs are up. Where CPUs are mismatched in violation of the boot protocol, WARN and set a taint (as we do for CPU other CPU feature mismatches) given that the firmware/bootloader is buggy and should be fixed. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-03-17arm64: apply alternatives for !SMP kernelsMark Rutland1-0/+12
Currently we only perform alternative patching for kernels built with CONFIG_SMP, as we call apply_alternatives_all() in smp.c, which is only built for CONFIG_SMP. Thus !SMP kernels may not have necessary alternatives patched in. This patch ensures that we call apply_alternatives_all() once all CPUs are booted, even for !SMP kernels, by having the smp_init_cpus() stub call this for !SMP kernels via up_late_init. A new wrapper, do_post_cpus_up_work, is added so we can hook other calls here later (e.g. boot mode logging). Cc: Andre Przywara <andre.przywara@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Fixes: e039ee4ee3fcf174 ("arm64: add alternative runtime patching") Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-01-23arm64: implement generic IOMMU configurationRobin Murphy1-0/+2
Add the necessary call to of_iommu_init. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-01-22arm64/efi: move virtmap init to early initcallArd Biesheuvel1-1/+0
Now that the create_mapping() code in mm/mmu.c is able to support setting up kernel page tables at initcall time, we can move the whole virtmap creation to arm64_enable_runtime_services() instead of having a distinct stage during early boot. This also allows us to drop the arm64-specific EFI_VIRTMAP flag. Signed-off-by: Ard Biesheuvel <ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-01-16arm64: respect mem= for EFIMark Rutland1-19/+0
When booting with EFI, we acquire the EFI memory map after parsing the early params. This unfortuantely renders the option useless as we call memblock_enforce_memory_limit (which uses memblock_remove_range behind the scenes) before we've added any memblocks. We end up removing nothing, then adding all of memory later when efi_init calls reserve_regions. Instead, we can log the limit and apply this later when we do the rest of the memblock work in memblock_init, which should work regardless of the presence of EFI. At the same time we may as well move the early parameter into arm64's mm/init.c, close to arm64_memblock_init. Any memory which must be mapped (e.g. for use by EFI runtime services) must be mapped explicitly reather than relying on the linear mapping, which may be truncated as a result of a mem= option passed on the kernel command line. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-01-12arm64/efi: remove idmap manipulations from UEFI codeArd Biesheuvel1-1/+0
Now that we have moved the call to SetVirtualAddressMap() to the stub, UEFI has no use for the ID map, so we can drop the code that installs ID mappings for UEFI memory regions. Acked-by: Leif Lindholm <leif.lindholm@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> Tested-by: Leif Lindholm <leif.lindholm@linaro.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
2015-01-12arm64/efi: move SetVirtualAddressMap() to UEFI stubArd Biesheuvel1-0/+1
In order to support kexec, the kernel needs to be able to deal with the state of the UEFI firmware after SetVirtualAddressMap() has been called. To avoid having separate code paths for non-kexec and kexec, let's move the call to SetVirtualAddressMap() to the stub: this will guarantee us that it will only be called once (since the stub is not executed during kexec), and ensures that the UEFI state is identical between kexec and normal boot. This implies that the layout of the virtual mapping needs to be created by the stub as well. All regions are rounded up to a naturally aligned multiple of 64 KB (for compatibility with 64k pages kernels) and recorded in the UEFI memory map. The kernel proper reads those values and installs the mappings in a dedicated set of page tables that are swapped in during UEFI Runtime Services calls. Acked-by: Leif Lindholm <leif.lindholm@linaro.org> Acked-by: Matt Fleming <matt.fleming@intel.com> Tested-by: Leif Lindholm <leif.lindholm@linaro.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
2015-01-08arm64/efi: add missing call to early_ioremap_reset()Ard Biesheuvel1-0/+1
The early ioremap support introduced by patch bf4b558eba92 ("arm64: add early_ioremap support") failed to add a call to early_ioremap_reset() at an appropriate time. Without this call, invocations of early_ioremap etc. that are done too late will go unnoticed and may cause corruption. This is exactly what happened when the first user of this feature was added in patch f84d02755f5a ("arm64: add EFI runtime services"). The early mapping of the EFI memory map is unmapped during an early initcall, at which time the early ioremap support is long gone. Fix by adding the missing call to early_ioremap_reset() to setup_arch(), and move the offending early_memunmap() to right after the point where the early mapping of the EFI memory map is last used. Fixes: f84d02755f5a ("arm64: add EFI runtime services") Cc: <stable@vger.kernel.org> Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2014-12-04arm64: Provide a namespace to NCAPSFabio Estevam1-1/+1
Building arm64.allmodconfig leads to the following warning: usb/gadget/function/f_ncm.c:203:0: warning: "NCAPS" redefined #define NCAPS (USB_CDC_NCM_NCAP_ETH_FILTER | USB_CDC_NCM_NCAP_CRC_MODE) ^ In file included from /home/build/work/batch/arch/arm64/include/asm/io.h:32:0, from /home/build/work/batch/include/linux/clocksource.h:19, from /home/build/work/batch/include/clocksource/arm_arch_timer.h:19, from /home/build/work/batch/arch/arm64/include/asm/arch_timer.h:27, from /home/build/work/batch/arch/arm64/include/asm/timex.h:19, from /home/build/work/batch/include/linux/timex.h:65, from /home/build/work/batch/include/linux/sched.h:19, from /home/build/work/batch/arch/arm64/include/asm/compat.h:25, from /home/build/work/batch/arch/arm64/include/asm/stat.h:23, from /home/build/work/batch/include/linux/stat.h:5, from /home/build/work/batch/include/linux/module.h:10, from /home/build/work/batch/drivers/usb/gadget/function/f_ncm.c:19: arch/arm64/include/asm/cpufeature.h:27:0: note: this is the location of the previous definition #define NCAPS 2 So add a ARM64 prefix to avoid such problem. Reported-by: Olof's autobuilder <build@lixom.net> Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2014-11-25arm64: Factor out fixmap initialization from ioremapLaura Abbott1-0/+1
The fixmap API was originally added for arm64 for early_ioremap purposes. It can be used for other purposes too so move the initialization from ioremap to somewhere more generic. This makes it obvious where the fixmap is being set up and allows for a cleaner implementation of __set_fixmap. Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Kees Cook <keescook@chromium.org> Signed-off-by: Laura Abbott <lauraa@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2014-11-25arm64: add cpu_capabilities bitmapAndre Przywara1-0/+3
For taking note if at least one CPU in the system needs a bug workaround or would benefit from a code optimization, we create a new bitmap to hold (artificial) feature bits. Since elf_hwcap is part of the userland ABI, we keep it alone and introduce a new data structure for that (along with some accessors). Signed-off-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2014-11-17arm64: Add COMPAT_HWCAP_LPAECatalin Marinas1-1/+2
Commit a469abd0f868 (ARM: elf: add new hwcap for identifying atomic ldrd/strd instructions) introduces HWCAP_ELF for 32-bit ARM applications. As LPAE is always present on arm64, report the corresponding compat HWCAP to user space. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: <stable@vger.kernel.org> # 3.11+ Signed-off-by: Will Deacon <will.deacon@arm.com>
2014-11-14arm64: Fix up /proc/cpuinfoMark Rutland1-24/+73
Commit d7a49086f263164a (arm64: cpuinfo: print info for all CPUs) attempted to clean up /proc/cpuinfo, but due to concerns regarding further changes was reverted in commit 5e39977edf6500fd (Revert "arm64: cpuinfo: print info for all CPUs"). There are two major issues with the arm64 /proc/cpuinfo format currently: * The "Features" line describes (only) the 64-bit hwcaps, which is problematic for some 32-bit applications which attempt to parse it. As the same names are used for analogous ISA features (e.g. aes) despite these generally being architecturally unrelated, it is not possible to simply append the 64-bit and 32-bit hwcaps in a manner that might not be misleading to some applications. Various potential solutions have appeared in vendor kernels. Typically the format of the Features line varies depending on whether the task is 32-bit. * Information is only printed regarding a single CPU. This does not match the ARM format, and does not provide sufficient information in big.LITTLE systems where CPUs are heterogeneous. The CPU information printed is queried from the current CPU's registers, which is racy w.r.t. cross-cpu migration. This patch attempts to solve these issues. The following changes are made: * When a task with a LINUX32 personality attempts to read /proc/cpuinfo, the "Features" line contains the decoded 32-bit hwcaps, as with the arm port. Otherwise, the decoded 64-bit hwcaps are shown. This aligns with the behaviour of COMPAT_UTS_MACHINE and COMPAT_ELF_PLATFORM. In the absense of compat support, the Features line is empty. The set of hwcaps injected into a task's auxval are unaffected. * Properties are printed per-cpu, as with the ARM port. The per-cpu information is queried from pre-recorded cpu information (as used by the sanity checks). * As with the previous attempt at fixing up /proc/cpuinfo, the hardware field is removed. The only users so far are 32-bit applications tied to particular boards, so no portable applications should be affected, and this should prevent future tying to particular boards. The following differences remain: * No model_name is printed, as this cannot be queried from the hardware and cannot be provided in a stable fashion. Use of the CPU {implementor,variant,part,revision} fields is sufficient to identify a CPU and is portable across arm and arm64. * The following system-wide properties are not provided, as they are not possible to provide generally. Programs relying on these are already tied to particular (32-bit only) boards: - Hardware - Revision - Serial No software has yet been identified for which these remaining differences are problematic. Cc: Greg Hackmann <ghackmann@google.com> Cc: Ian Campbell <ijc@hellion.org.uk> Cc: Serban Constantinescu <serban.constantinescu@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: cross-distro@lists.linaro.org Cc: linux-api@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2014-11-06arm64: log physical ID of boot CPUMark Rutland1-1/+4
In certain debugging scenarios it's useful to know the physical ID (i.e. the MPIDR_EL1.Aff* fields) of the boot CPU, but we don't currently log this as we do for 32-bit ARM kernels. This patch makes the kernel log the physical ID of the boot CPU early in the boot process. The CPU logical map initialisation is folded in to smp_setup_processor_id (which contrary to its name is also called by UP kernels). This is called before setup_arch, so should not adversely affect existing cpu_logical_map users. Acked-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Lorenzo Pieralisis <lorenzo.pieralisi@arm.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2014-11-06arm64/dt: add machine name to kernel call stack dump outputArd Biesheuvel1-0/+1
This installs the machine name as recorded by setup_machine_fdt() as dump stack arch description. This results in the string to be included in call stack dumps, as is shown here: ... Bad mode in Synchronous Abort handler detected, code 0x84000005 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.18.0-rc2+ #548 > Hardware name: linux,dummy-virt (DT) task: ffffffc07c870000 ti: ffffffc07c878000 task.ti: ffffffc07c878000 PC is at 0x0 ... Note that systems that support DMI/SMBIOS may override this later. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2014-09-15setup: Move unmask of async interrupts after possible earlycon setupJon Masters1-5/+6
The kernel wants to enable reporting of asynchronous interrupts (i.e. System Errors) as early as possible. But if this happens too early then any pending System Error on initial entry into the kernel may never be reported where a user can see it. This situation will occur if the kernel is configured with CONFIG_PANIC_ON_OOPS set and (default or command line) enabled, in which case the kernel will panic as intended, however the associated logging messages indicating this failure condition will remain only in the kernel ring buffer and never be flushed out to the (not yet configured) console. Therefore, this patch moves the enabling of asynchronous interrupts during early setup to as early as reasonable, but after parsing any possible earlycon parameters setting up earlycon. Signed-off-by: Jon Masters <jcm@redhat.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-09-01Revert "arm64: cpuinfo: print info for all CPUs"Will Deacon1-18/+22
It turns out that vendors are relying on the format of /proc/cpuinfo, and we've even spotted out-of-tree hacks attempting to make it look identical to the format used by arch/arm/. That means we can't afford to churn this interface in mainline, so revert the recent reformatting of the file for arm64 pending discussions on the list to find out what people actually want. This reverts commit d7a49086f263164a2c4c178eb76412d48cd671d7. Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2014-07-31Revert "arm64: dmi: Add SMBIOS/DMI support"Will Deacon1-2/+0
This reverts commit a28e3f4b90543f7c249a956e3ca518e243a04618. Ard and Yi Li report that this patch is broken by design, so revert it and let them sort it out for 3.18 instead. Reported-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2014-07-21arm64: dmi: Add SMBIOS/DMI supportYi Li1-0/+2
SMbios is important for server hardware vendors. It implements a spec for providing descriptive information about the platform. Things like serial numbers, physical layout of the ports, build configuration data, and the like. This has been tested by dmidecode and lshw tools. Signed-off-by: Yi Li <yi.li@linaro.org> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-07-18arm64: cpuinfo: print info for all CPUsMark Rutland1-22/+18
Currently reading /proc/cpuinfo will result in information being read out of the MIDR_EL1 of the current CPU, and the information is not associated with any particular logical CPU number. This is problematic for systems with heterogeneous CPUs (i.e. big.LITTLE) where MIDR fields will vary across CPUs, and the output will differ depending on the executing CPU. This patch reorganises the code responsible for /proc/cpuinfo to print information per-cpu. In the process, we perform several cleanups: * Property names are coerced to lower-case (to match "processor" as per glibc's expectations). * Property names are simplified and made to match the MIDR field names. * Revision is changed to hex as with every other field. * The meaningless Architecture property is removed. * The ripe-for-abuse Machine field is removed. The features field (a human-readable representation of the hwcaps) remains printed once, as this is expected to remain in use as the globally support CPU features. To enable the possibility of the addition of per-cpu HW feature information later, this is printed before any CPU-specific information. Comments are added to guide userspace developers in the right direction (using the hwcaps provided in auxval). Hopefully where userspace applications parse /proc/cpuinfo rather than using the readily available hwcaps, they limit themselves to reading said first line. If CPU features differ from each other, the previously installed sanity checks will give us some advance notice with warnings and TAINT_CPU_OUT_OF_SPEC. If we are lucky, we will never see such systems. Rework will be required in many places to support such systems anyway. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Marcus Shawcroft <marcus.shawcroft@arm.com> Cc: Peter Maydell <peter.maydell@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> [catalin.marinas@arm.com: remove machine_name as it is no longer reported] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-07-18arm64: cpuinfo: record cpu system register valuesMark Rutland1-3/+4
Several kernel subsystems need to know details about CPU system register values, sometimes for CPUs other than that they are executing on. Rather than hard-coding system register accesses and cross-calls for these cases, this patch adds logic to record various system register values at boot-time. This may be used for feature reporting, firmware bug detection, etc. Separate hooks are added for the boot and hotplug paths to enable one-time intialisation and cold/warm boot value mismatch detection in later patches. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-06-06Merge tag 'arm64-upstream' of ↵Linus Torvalds1-1/+15
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux into next Pull arm64 updates from Catalin Marinas: - Optimised assembly string/memory routines (based on the AArch64 Cortex Strings library contributed to glibc but re-licensed under GPLv2) - Optimised crypto algorithms making use of the ARMv8 crypto extensions (together with kernel API for using FPSIMD instructions in interrupt context) - Ftrace support - CPU topology parsing from DT - ESR_EL1 (Exception Syndrome Register) exposed to user space signal handlers for SIGSEGV/SIGBUS (useful to emulation tools like Qemu) - 1GB section linear mapping if applicable - Barriers usage clean-up - Default pgprot clean-up Conflicts as per Catalin. * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (57 commits) arm64: kernel: initialize broadcast hrtimer based clock event device arm64: ftrace: Add system call tracepoint arm64: ftrace: Add CALLER_ADDRx macros arm64: ftrace: Add dynamic ftrace support arm64: Add ftrace support ftrace: Add arm64 support to recordmcount arm64: Add 'notrace' attribute to unwind_frame() for ftrace arm64: add __ASSEMBLY__ in asm/insn.h arm64: Fix linker script entry point arm64: lib: Implement optimized string length routines arm64: lib: Implement optimized string compare routines arm64: lib: Implement optimized memcmp routine arm64: lib: Implement optimized memset routine arm64: lib: Implement optimized memmove routine arm64: lib: Implement optimized memcpy routine arm64: defconfig: enable a few more common/useful options in defconfig ftrace: Make CALLER_ADDRx macros more generic arm64: Fix deadlock scenario with smp_send_stop() arm64: Fix machine_shutdown() definition arm64: Support arch_irq_work_raise() via self IPIs ...
2014-06-05Merge branch 'arm64-efi-for-linus' of ↵Linus Torvalds1-0/+5
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into next Pull ARM64 EFI update from Peter Anvin: "By agreement with the ARM64 EFI maintainers, we have agreed to make -tip the upstream for all EFI patches. That is why this patchset comes from me :) This patchset enables EFI stub support for ARM64, like we already have on x86" * 'arm64-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: arm64: efi: only attempt efi map setup if booting via EFI efi/arm64: ignore dtb= when UEFI SecureBoot is enabled doc: arm64: add description of EFI stub support arm64: efi: add EFI stub doc: arm: add UEFI support documentation arm64: add EFI runtime services efi: Add shared FDT related functions for ARM/ARM64 arm64: Add function to create identity mappings efi: add helper function to get UEFI params from FDT doc: efi-stub.txt updates for ARM lib: add fdt_empty_tree.c
2014-05-09arm64: Clean up the default pgprot settingCatalin Marinas1-1/+0
The primary aim of this patchset is to remove the pgprot_default and prot_sect_default global variables and rely strictly on predefined values. The original goal was to be able to run SMP kernels on UP hardware by not setting the Shareability bit. However, it is unlikely to see UP ARMv8 hardware and even if we do, the Shareability bit is no longer assumed to disable cacheable accesses. A side effect is that the device mappings now have the Shareability attribute set. The hardware, however, should ignore it since Device accesses are always Outer Shareable. Following the removal of the two global variables, there is some PROT_* macro reshuffling and cleanup, including the __PAGE_* macros (replaced by PAGE_*). Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Will Deacon <will.deacon@arm.com>
2014-05-09arm64: Implement cache_line_size() based on CTR_EL0.CWGCatalin Marinas1-0/+15
The hardware provides the maximum cache line size in the system via the CTR_EL0.CWG bits. This patch implements the cache_line_size() function to read such information, together with a sanity check if the statically defined L1_CACHE_BYTES is smaller than the hardware value. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Will Deacon <will.deacon@arm.com>
2014-05-03arm64: Use bus notifiers to set per-device coherent DMA opsCatalin Marinas1-1/+1
Recently, the default DMA ops have been changed to non-coherent for alignment with 32-bit ARM platforms (and DT files). This patch adds bus notifiers to be able to set the coherent DMA ops (with no cache maintenance) for devices explicitly marked as coherent via the "dma-coherent" DT property. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-04-30arm64: add EFI runtime servicesMark Salter1-0/+5
This patch adds EFI runtime support for arm64. This runtime support allows the kernel to access various EFI runtime services provided by EFI firmware. Things like reboot, real time clock, EFI boot variables, and others. This functionality is supported for little endian kernels only. The UEFI firmware standard specifies that the firmware be little endian. A future patch is expected to add support for big endian kernels running with little endian firmware. Signed-off-by: Mark Salter <msalter@redhat.com> [ Remove unnecessary cache/tlb maintenance. ] Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-04-25arm64: init: Move of_clk_init to time_initChanho Min1-1/+0
Clock providers should be initialized before clocksource_of_init. If not, Clock source initialization can be fail to get the clock. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Chanho Min <chanho.min@lge.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-04-07arm64: add early_ioremap supportMark Salter1-0/+2
Add support for early IO or memory mappings which are needed before the normal ioremap() is usable. This also adds fixmap support for permanent fixed mappings such as that used by the earlyprintk device register region. Signed-off-by: Mark Salter <msalter@redhat.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Borislav Petkov <borislav.petkov@amd.com> Cc: Dave Young <dyoung@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07arm64: initialize pgprot info earlier in bootMark Salter1-0/+2
Presently, paging_init() calls init_mem_pgprot() to initialize pgprot values used by macros such as PAGE_KERNEL, PAGE_KERNEL_EXEC, etc. The new fixmap and early_ioremap support also needs to use these macros before paging_init() is called. This patch moves the init_mem_pgprot() call out of paging_init() and into setup_arch() so that pgprot_default gets initialized in time for fixmap and early_ioremap. Signed-off-by: Mark Salter <msalter@redhat.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Borislav Petkov <borislav.petkov@amd.com> Cc: Dave Young <dyoung@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-03-04arm64: advertise ARMv8 extensions to 32-bit compat ELF binariesArd Biesheuvel1-0/+32
This adds support for advertising the presence of ARMv8 Crypto Extensions in the Aarch32 execution state to 32-bit ELF binaries running in 32-bit compat mode under the arm64 kernel. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-03-04arm64: add AT_HWCAP2 support for 32-bit compatArd Biesheuvel1-0/+1
Add support for the ELF auxv entry AT_HWCAP2 when running 32-bit ELF binaries in compat mode. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-12-19Merge tag 'arm64-suspend' of git://linux-arm.org/linux-2.6-lp into upstreamCatalin Marinas1-0/+70
* tag 'arm64-suspend' of git://linux-arm.org/linux-2.6-lp: arm64: add CPU power management menu/entries arm64: kernel: add PM build infrastructure arm64: kernel: add CPU idle call arm64: enable generic clockevent broadcast arm64: kernel: implement HW breakpoints CPU PM notifier arm64: kernel: refactor code to install/uninstall breakpoints arm: kvm: implement CPU PM notifier arm64: kernel: implement fpsimd CPU PM notifier arm64: kernel: cpu_{suspend/resume} implementation arm64: kernel: suspend/resume registers save/restore arm64: kernel: build MPIDR_EL1 hash function data structure arm64: kernel: add MPIDR_EL1 accessors macros Conflicts: arch/arm64/Kconfig
2013-12-19arm64: Add hwcaps for crypto and CRC32 extensions.Steve Capper1-0/+37
Advertise the optional cryptographic and CRC32 instructions to user space where present. Several hwcap bits [3-7] are allocated. Signed-off-by: Steve Capper <steve.capper@linaro.org> [bit 2 is taken now so use bits 3-7 instead] Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-12-19arm64: Remove outdated commentLiviu Dudau1-5/+0
Code referenced in the comment has moved to arch/arm64/kernel/cputable.c Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-12-19arm64: percpu: implement optimised pcpu access using tpidr_el1Will Deacon1-0/+10
This patch implements optimised percpu variable accesses using the el1 r/w thread register (tpidr_el1) along the same lines as arch/arm/. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-12-16arm64: kernel: build MPIDR_EL1 hash function data structureLorenzo Pieralisi1-0/+70
On ARM64 SMP systems, cores are identified by their MPIDR_EL1 register. The MPIDR_EL1 guidelines in the ARM ARM do not provide strict enforcement of MPIDR_EL1 layout, only recommendations that, if followed, split the MPIDR_EL1 on ARM 64 bit platforms in four affinity levels. In multi-cluster systems like big.LITTLE, if the affinity guidelines are followed, the MPIDR_EL1 can not be considered a linear index. This means that the association between logical CPU in the kernel and the HW CPU identifier becomes somewhat more complicated requiring methods like hashing to associate a given MPIDR_EL1 to a CPU logical index, in order for the look-up to be carried out in an efficient and scalable way. This patch provides a function in the kernel that starting from the cpu_logical_map, implement collision-free hashing of MPIDR_EL1 values by checking all significative bits of MPIDR_EL1 affinity level bitfields. The hashing can then be carried out through bits shifting and ORing; the resulting hash algorithm is a collision-free though not minimal hash that can be executed with few assembly instructions. The mpidr_el1 is filtered through a mpidr mask that is built by checking all bits that toggle in the set of MPIDR_EL1s corresponding to possible CPUs. Bits that do not toggle do not carry information so they do not contribute to the resulting hash. Pseudo code: /* check all bits that toggle, so they are required */ for (i = 1, mpidr_el1_mask = 0; i < num_possible_cpus(); i++) mpidr_el1_mask |= (cpu_logical_map(i) ^ cpu_logical_map(0)); /* * Build shifts to be applied to aff0, aff1, aff2, aff3 values to hash the * mpidr_el1 * fls() returns the last bit set in a word, 0 if none * ffs() returns the first bit set in a word, 0 if none */ fs0 = mpidr_el1_mask[7:0] ? ffs(mpidr_el1_mask[7:0]) - 1 : 0; fs1 = mpidr_el1_mask[15:8] ? ffs(mpidr_el1_mask[15:8]) - 1 : 0; fs2 = mpidr_el1_mask[23:16] ? ffs(mpidr_el1_mask[23:16]) - 1 : 0; fs3 = mpidr_el1_mask[39:32] ? ffs(mpidr_el1_mask[39:32]) - 1 : 0; ls0 = fls(mpidr_el1_mask[7:0]); ls1 = fls(mpidr_el1_mask[15:8]); ls2 = fls(mpidr_el1_mask[23:16]); ls3 = fls(mpidr_el1_mask[39:32]); bits0 = ls0 - fs0; bits1 = ls1 - fs1; bits2 = ls2 - fs2; bits3 = ls3 - fs3; aff0_shift = fs0; aff1_shift = 8 + fs1 - bits0; aff2_shift = 16 + fs2 - (bits0 + bits1); aff3_shift = 32 + fs3 - (bits0 + bits1 + bits2); u32 hash(u64 mpidr_el1) { u32 l[4]; u64 mpidr_el1_masked = mpidr_el1 & mpidr_el1_mask; l[0] = mpidr_el1_masked & 0xff; l[1] = mpidr_el1_masked & 0xff00; l[2] = mpidr_el1_masked & 0xff0000; l[3] = mpidr_el1_masked & 0xff00000000; return (l[0] >> aff0_shift | l[1] >> aff1_shift | l[2] >> aff2_shift | l[3] >> aff3_shift); } The hashing algorithm relies on the inherent properties set in the ARM ARM recommendations for the MPIDR_EL1. Exotic configurations, where for instance the MPIDR_EL1 values at a given affinity level have large holes, can end up requiring big hash tables since the compression of values that can be achieved through shifting is somewhat crippled when holes are present. Kernel warns if the number of buckets of the resulting hash table exceeds the number of possible CPUs by a factor of 4, which is a symptom of a very sparse HW MPIDR_EL1 configuration. The hash algorithm is quite simple and can easily be implemented in assembly code, to be used in code paths where the kernel virtual address space is not set-up (ie cpu_resume) and instruction and data fetches are strongly ordered so code must be compact and must carry out few data accesses. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
2013-11-25arm64: Unmask asynchronous aborts when in kernel modeCatalin Marinas1-0/+5
The asynchronous aborts are generally fatal for the kernel but they can be masked via the pstate A bit. If a system error happens while in kernel mode, it won't be visible until returning to user space. This patch enables this kind of abort early to help identifying the cause. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>