From 336868afbaae2d153fc20268a21747c31e5071b8 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Tue, 14 Sep 2021 14:10:34 +0200 Subject: [PATCH] powerpc: smp: remove hack to obtain offset of task_struct::cpu Instead of relying on awful hacks to obtain the offset of the cpu field in struct task_struct, move it back into struct thread_info, which does not create the same level of circular dependency hell when trying to include the header file that defines it. Signed-off-by: Ard Biesheuvel Acked-by: Mark Rutland Acked-by: Michael Ellerman --- arch/powerpc/Makefile | 11 ----------- arch/powerpc/include/asm/smp.h | 17 +---------------- arch/powerpc/kernel/asm-offsets.c | 2 -- 3 files changed, 1 insertion(+), 29 deletions(-) diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile index aa6808e70647..54cad1faa5d0 100644 --- a/arch/powerpc/Makefile +++ b/arch/powerpc/Makefile @@ -446,17 +446,6 @@ else endif endif -ifdef CONFIG_SMP -ifdef CONFIG_PPC32 -prepare: task_cpu_prepare - -PHONY += task_cpu_prepare -task_cpu_prepare: prepare0 - $(eval KBUILD_CFLAGS += -D_TASK_CPU=$(shell awk '{if ($$2 == "TASK_CPU") print $$3;}' include/generated/asm-offsets.h)) - -endif # CONFIG_PPC32 -endif # CONFIG_SMP - PHONY += checkbin # Check toolchain versions: # - gcc-4.6 is the minimum kernel-wide version so nothing required. diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h index 7ef1cd8168a0..007332a4a732 100644 --- a/arch/powerpc/include/asm/smp.h +++ b/arch/powerpc/include/asm/smp.h @@ -87,22 +87,7 @@ int is_cpu_dead(unsigned int cpu); /* 32-bit */ extern int smp_hw_index[]; -/* - * This is particularly ugly: it appears we can't actually get the definition - * of task_struct here, but we need access to the CPU this task is running on. - * Instead of using task_struct we're using _TASK_CPU which is extracted from - * asm-offsets.h by kbuild to get the current processor ID. - * - * This also needs to be safeguarded when building asm-offsets.s because at - * that time _TASK_CPU is not defined yet. It could have been guarded by - * _TASK_CPU itself, but we want the build to fail if _TASK_CPU is missing - * when building something else than asm-offsets.s - */ -#ifdef GENERATING_ASM_OFFSETS -#define raw_smp_processor_id() (0) -#else -#define raw_smp_processor_id() (*(unsigned int *)((void *)current + _TASK_CPU)) -#endif +#define raw_smp_processor_id() (current_thread_info()->cpu) #define hard_smp_processor_id() (smp_hw_index[smp_processor_id()]) static inline int get_hard_smp_processor_id(int cpu) diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c index e37e4546034e..cc05522f50bf 100644 --- a/arch/powerpc/kernel/asm-offsets.c +++ b/arch/powerpc/kernel/asm-offsets.c @@ -9,8 +9,6 @@ * #defines from the assembly-language output. */ -#define GENERATING_ASM_OFFSETS /* asm/smp.h */ - #include #include #include