Hosts the 0x221E linux distro kernel. https://git.0xinfinity.dev/distro/kernel.git/atom?h=linux-4.10.y 2016-11-16T18:05:10Z 2016-11-16T18:05:10Z Suzuki K Poulose 2016-11-08T13:56:21Z urn:sha1:82e0191a1aa11abfddb22c8944989b7735560efc The arm64 kernel assumes that FP/ASIMD units are always present and accesses the FP/ASIMD specific registers unconditionally. This could cause problems when they are absent. This patch adds the support for kernel handling systems without FP/ASIMD by skipping the register access within the kernel. For kvm, we trap the accesses to FP/ASIMD and inject an undefined instruction exception to the VM. The callers of the exported kernel_neon_begin_partial() should make sure that the FP/ASIMD is supported. Cc: Will Deacon <will.deacon@arm.com> Cc: Christoffer Dall <christoffer.dall@linaro.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> [catalin.marinas@arm.com: add comment on the ARM64_HAS_NO_FPSIMD conflict and the new location] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> 2016-09-19T19:44:25Z Sebastian Andrzej Siewior 2016-09-06T17:04:37Z urn:sha1:c23a7266e6599e74305cc5b790f93398bb212380 Install the callbacks via the state machine. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: rt@linutronix.de Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/20160906170457.32393-2-bigeasy@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de> 2016-03-04T18:19:17Z Adam Buchbinder 2016-02-24T17:52:41Z urn:sha1:ef769e320863a186e489e3f66ed8df60487fe9bf Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> 2015-12-02T12:17:11Z Jisheng Zhang 2015-11-20T09:59:10Z urn:sha1:a7c61a3452d39078919f0e1f493ff966fb64f0db These functions/variables are not needed after booting, so mark them as __init or __initdata. Signed-off-by: Jisheng Zhang <jszhang@marvell.com> Signed-off-by: Will Deacon <will.deacon@arm.com> 2015-10-21T14:35:59Z Suzuki K. Poulose 2015-10-19T13:24:53Z urn:sha1:fe80f9f2da1006a4308c2bc018ee1d67f10dd8d0 The FP/ASIMD is detected in fpsimd_init(), which is built-in unconditionally. Lets move the hwcap handling to the central place. Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com> Tested-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> 2015-08-27T08:55:26Z Ard Biesheuvel 2015-08-27T06:12:33Z urn:sha1:674c242c9323d3c293fc4f9a3a3a619fe3063290 When a task calls execve(), its FP/SIMD state is flushed so that none of the original program state is observeable by the incoming program. However, since this flushing consists of setting the in-memory copy of the FP/SIMD state to all zeroes, the CPU field is set to CPU 0 as well, which indicates to the lazy FP/SIMD preserve/restore code that the FP/SIMD state does not need to be reread from memory if the task is scheduled again on CPU 0 without any other tasks having entered userland (or used the FP/SIMD in kernel mode) on the same CPU in the mean time. If this happens, the FP/SIMD state of the old program will still be present in the registers when the new program starts. So set the CPU field to the invalid value of NR_CPUS when performing the flush, by calling fpsimd_flush_task_state(). Cc: <stable@vger.kernel.org> Reported-by: Chunyan Zhang <chunyan.zhang@spreadtrum.com> Reported-by: Janet Liu <janet.liu@spreadtrum.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com> 2015-06-11T16:08:11Z Janet Liu 2015-06-11T04:02:45Z urn:sha1:32365e64a20edcc783137ad17fdd951ab814a2fe Now FPSIMD don't handle HOTPLUG_CPU. This introduces bug after cpu down/up process. After cpu down/up process, the FPSMID hardware register is default value, not any process's fpsimd context. when CPU_DEAD set cpu's fpsimd_state to NULL, it will force to load the fpsimd context for the thread, to avoid the chance to skip to load the context. If process A is the last user process on CPU N before cpu down, and the first user process on the same CPU N after cpu up, A's fpsimd_state.cpu is the current cpu id, and per_cpu(fpsimd_last_state) points A's fpsimd_state, so kernel will not reload the context during it return to user space. Signed-off-by: Janet Liu <janet.liu@spreadtrum.com> Signed-off-by: Xiongshan An <xiongshan.an@spreadtrum.com> Signed-off-by: Chunyan Zhang <chunyan.zhang@spreadtrum.com> [catalin.marinas@arm.com: some mostly cosmetic clean-ups] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> 2014-09-01T11:55:21Z Leo Yan 2014-09-01T03:09:51Z urn:sha1:7c68a9cc040216c902f93f9c80305df55d9beff7 Now arm64 defers reloading FPSIMD state, but this optimization also introduces the bug after cpu resume back from low power mode. The reason is after the cpu has been powered off, s/w need set the cpu's fpsimd_last_state to NULL so that it will force to reload FPSIMD state for the thread, otherwise there has the chance to meet the condition for both the task's fpsimd_state.cpu field contains the id of the current cpu, and the cpu's fpsimd_last_state per-cpu variable points to the task's fpsimd_state, so finally kernel will skip to reload the context during it return back to userland. Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Leo Yan <leoy@marvell.com> Signed-off-by: Will Deacon <will.deacon@arm.com> 2014-05-08T09:31:57Z Ard Biesheuvel 2014-02-24T14:26:29Z urn:sha1:190f1ca85d071114930dd7abe6b5d103e9d5572f This patch modifies kernel_neon_begin() and kernel_neon_end(), so they may be called from any context. To address the case where only a couple of registers are needed, kernel_neon_begin_partial(u32) is introduced which takes as a parameter the number of bottom 'n' NEON q-registers required. To mark the end of such a partial section, the regular kernel_neon_end() should be used. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> 2014-05-08T09:31:57Z Ard Biesheuvel 2014-05-08T09:20:23Z urn:sha1:005f78cd88494457ed38ce817f4e3fe5d372f0cb If a task gets scheduled out and back in again and nothing has touched its FPSIMD state in the mean time, there is really no reason to reload it from memory. Similarly, repeated calls to kernel_neon_begin() and kernel_neon_end() will preserve and restore the FPSIMD state every time. This patch defers the FPSIMD state restore to the last possible moment, i.e., right before the task returns to userland. If a task does not return to userland at all (for any reason), the existing FPSIMD state is preserved and may be reused by the owning task if it gets scheduled in again on the same CPU. This patch adds two more functions to abstract away from straight FPSIMD register file saves and restores: - fpsimd_restore_current_state -> ensure current's FPSIMD state is loaded - fpsimd_flush_task_state -> invalidate live copies of a task's FPSIMD state Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>