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2017-11-02arm64: explicitly mask all exceptionsJames Morse
There are a few places where we want to mask all exceptions. Today we do this in a piecemeal fashion, typically we expect the caller to have masked irqs and the arch code masks debug exceptions, ignoring serror which is probably masked. Make it clear that 'mask all exceptions' is the intention by adding helpers to do exactly that. This will let us unmask SError without having to add 'oh and SError' to these paths. Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-08-21arm64: kexec: have own crash_smp_send_stop() for crash dump for nonpanic coresHoeun Ryu
Commit 0ee5941 : (x86/panic: replace smp_send_stop() with kdump friendly version in panic path) introduced crash_smp_send_stop() which is a weak function and can be overridden by architecture codes to fix the side effect caused by commit f06e515 : (kernel/panic.c: add "crash_kexec_post_ notifiers" option). ARM64 architecture uses the weak version function and the problem is that the weak function simply calls smp_send_stop() which makes other CPUs offline and takes away the chance to save crash information for nonpanic CPUs in machine_crash_shutdown() when crash_kexec_post_notifiers kernel option is enabled. Calling smp_send_crash_stop() in machine_crash_shutdown() is useless because all nonpanic CPUs are already offline by smp_send_stop() in this case and smp_send_crash_stop() only works against online CPUs. The result is that secondary CPUs registers are not saved by crash_save_cpu() and the vmcore file misreports these CPUs as being offline. crash_smp_send_stop() is implemented to fix this problem by replacing the existing smp_send_crash_stop() and adding a check for multiple calling to the function. The function (strong symbol version) saves crash information for nonpanic CPUs and machine_crash_shutdown() tries to save crash information for nonpanic CPUs only when crash_kexec_post_notifiers kernel option is disabled. * crash_kexec_post_notifiers : false panic() __crash_kexec() machine_crash_shutdown() crash_smp_send_stop() <= save crash dump for nonpanic cores * crash_kexec_post_notifiers : true panic() crash_smp_send_stop() <= save crash dump for nonpanic cores __crash_kexec() machine_crash_shutdown() crash_smp_send_stop() <= just return. Signed-off-by: Hoeun Ryu <hoeun.ryu@gmail.com> Reviewed-by: James Morse <james.morse@arm.com> Tested-by: James Morse <james.morse@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-04-05arm64: kdump: add VMCOREINFO's for user-space toolsAKASHI Takahiro
In addition to common VMCOREINFO's defined in crash_save_vmcoreinfo_init(), we need to know, for crash utility, - kimage_voffset - PHYS_OFFSET to examine the contents of a dump file (/proc/vmcore) correctly due to the introduction of KASLR (CONFIG_RANDOMIZE_BASE) in v4.6. - VA_BITS is also required for makedumpfile command. arch_crash_save_vmcoreinfo() appends them to the dump file. More VMCOREINFO's may be added later. Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Reviewed-by: James Morse <james.morse@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-04-05arm64: kdump: implement machine_crash_shutdown()AKASHI Takahiro
Primary kernel calls machine_crash_shutdown() to shut down non-boot cpus and save registers' status in per-cpu ELF notes before starting crash dump kernel. See kernel_kexec(). Even if not all secondary cpus have shut down, we do kdump anyway. As we don't have to make non-boot(crashed) cpus offline (to preserve correct status of cpus at crash dump) before shutting down, this patch also adds a variant of smp_send_stop(). Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Reviewed-by: James Morse <james.morse@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-04-05arm64: hibernate: preserve kdump image around hibernationAKASHI Takahiro
Since arch_kexec_protect_crashkres() removes a mapping for crash dump kernel image, the loaded data won't be preserved around hibernation. In this patch, helper functions, crash_prepare_suspend()/ crash_post_resume(), are additionally called before/after hibernation so that the relevant memory segments will be mapped again and preserved just as the others are. In addition, to minimize the size of hibernation image, crash_is_nosave() is added to pfn_is_nosave() in order to recognize only the pages that hold loaded crash dump kernel image as saveable. Hibernation excludes any pages that are marked as Reserved and yet "nosave." Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-04-05arm64: kdump: protect crash dump kernel memoryTakahiro Akashi
arch_kexec_protect_crashkres() and arch_kexec_unprotect_crashkres() are meant to be called by kexec_load() in order to protect the memory allocated for crash dump kernel once the image is loaded. The protection is implemented by unmapping the relevant segments in crash dump kernel memory, rather than making it read-only as other archs do, to prevent coherency issues due to potential cache aliasing (with mismatched attributes). Page-level mappings are consistently used here so that we can change the attributes of segments in page granularity as well as shrink the region also in page granularity through /sys/kernel/kexec_crash_size, putting the freed memory back to buddy system. Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-06-27arm64/kexec: Add pr_debug outputGeoff Levand
To aid in debugging kexec problems or when adding new functionality to kexec add a new routine kexec_image_info() and several inline pr_debug statements. Signed-off-by: Geoff Levand <geoff@infradead.org> Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-06-27arm64/kexec: Add core kexec supportGeoff Levand
Add three new files, kexec.h, machine_kexec.c and relocate_kernel.S to the arm64 architecture that add support for the kexec re-boot mechanism (CONFIG_KEXEC) on arm64 platforms. Signed-off-by: Geoff Levand <geoff@infradead.org> Reviewed-by: James Morse <james.morse@arm.com> [catalin.marinas@arm.com: removed dead code following James Morse's comments] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>