From 03dce595270f22d59a6f37e9170287c1afd94bc2 Mon Sep 17 00:00:00 2001 From: "Maciej W. Rozycki" Date: Tue, 12 May 2015 15:20:57 +0100 Subject: [PATCH] MIPS: Fix a preemption issue with thread's FPU defaults Fix "BUG: using smp_processor_id() in preemptible" reported in accesses to thread's FPU defaults: the value to initialise FSCR to at program startup, the FCSR r/w mask and the contents of FIR in full FPU emulation, removing a regression introduced with 9b26616c [MIPS: Respect the ISA level in FCSR handling] and f6843626 [MIPS: math-emu: Set FIR feature flags for full emulation]. Use `boot_cpu_data' to obtain the data from, following the approach that `cpu_has_*' macros take and avoiding the call to `smp_processor_id' made in the reference to `current_cpu_data'. The contents of FSCR have to be consistent across processors in an SMP system, the settings there must not change as a thread is migrated across processors. And the contents of FIR are guaranteed to be consistent in FPU emulation, by definition. Signed-off-by: Maciej W. Rozycki Tested-by: Ezequiel Garcia Tested-by: Paul Martin Cc: Markos Chandras Cc: James Hogan Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10030/ Signed-off-by: Ralf Baechle --- Reading git-format-patch failed