Commit 2a2e8202 authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Helge Deller
Browse files

parisc: move CPU field back into thread_info 



In commit 2214c0e7 ("parisc: Move thread_info into task struct")
PA-RISC gained support for THREAD_INFO_IN_TASK while changes were
already underway to keep the CPU field in thread_info rather than move
it into task_struct when THREAD_INFO_IN_TASK is enabled. The result is a
broken build for all PA-RISC configs that enable SMP.

So let's partially revert that commit, and get rid of the ugly hack to
get at the offset of task_struct::cpu without having to include
linux/sched.h, and put the CPU field back where it was before.

Reported-by: default avatarGuenter Roeck <linux@roeck-us.net>
Fixes: bcf9033e ("sched: move CPU field back into thread_info if THREAD_INFO_IN_TASK=y")
Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
Signed-off-by: default avatarHelge Deller <deller@gmx.de>
parent 7e992711

arch/parisc/include/asm/smp.h

+2 −17
Original line number Diff line number Diff line
@@ -32,25 +32,10 @@ extern void smp_send_all_nop(void); 
extern void arch_send_call_function_single_ipi(int cpu);

extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);



#define raw_smp_processor_id()		(current_thread_info()->cpu)



#endif /* !ASSEMBLY */



/*

 * 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

#include <asm/asm-offsets.h>

#define raw_smp_processor_id()		(*(unsigned int *)((void *)current + TASK_CPU))

#endif

#else /* CONFIG_SMP */



static inline void smp_send_all_nop(void) { return; }

arch/parisc/include/asm/thread_info.h

+3 −0
Original line number Diff line number Diff line
@@ -9,6 +9,9 @@ 
struct thread_info {

	unsigned long flags;		/* thread_info flags (see TIF_*) */

	int preempt_count;		/* 0=premptable, <0=BUG; will also serve as bh-counter */

#ifdef CONFIG_SMP

	unsigned int cpu;

#endif

};



#define INIT_THREAD_INFO(tsk)			\

arch/parisc/kernel/asm-offsets.c

+0 −5
Original line number Diff line number Diff line
@@ -14,8 +14,6 @@ 
 *    Copyright (C) 2003 James Bottomley <jejb at parisc-linux.org>

 */



#define GENERATING_ASM_OFFSETS /* asm/smp.h */



#include <linux/types.h>

#include <linux/sched.h>

#include <linux/thread_info.h>
@@ -39,9 +37,6 @@ int main(void) 
{

	DEFINE(TASK_TI_FLAGS, offsetof(struct task_struct, thread_info.flags));

	DEFINE(TASK_STACK, offsetof(struct task_struct, stack));

#ifdef CONFIG_SMP

	DEFINE(TASK_CPU, offsetof(struct task_struct, cpu));

#endif

	BLANK();

	DEFINE(TASK_REGS, offsetof(struct task_struct, thread.regs));

	DEFINE(TASK_PT_PSW, offsetof(struct task_struct, thread.regs.gr[ 0]));

arch/parisc/kernel/smp.c

+0 −2
Original line number Diff line number Diff line
@@ -339,8 +339,6 @@ int smp_boot_one_cpu(int cpuid, struct task_struct *idle) 
	const struct cpuinfo_parisc *p = &per_cpu(cpu_data, cpuid);

	long timeout;



	idle->cpu = cpuid;



	/* Let _start know what logical CPU we're booting

	** (offset into init_tasks[],cpu_data[])

	*/