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parisc: move CPU field back into thread_info

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In commit 2214c0e772 ("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: Guenter Roeck <linux@roeck-us.net>
Fixes: bcf9033e54 ("sched: move CPU field back into thread_info if THREAD_INFO_IN_TASK=y")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Helge Deller <deller@gmx.de>
This commit is contained in:
Ard Biesheuvel 2021-11-04 09:26:28 +01:00 committed by Helge Deller
parent 7e992711dd
commit 2a2e8202c7
4 changed files with 5 additions and 24 deletions
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19
arch/parisc/include/asm/smp.h
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@ -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_single_ipi(int cpu);
extern void arch_send_call_function_ipi_mask(const struct cpumask *mask); extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);
#define raw_smp_processor_id() (current_thread_info()->cpu)
#endif /* !ASSEMBLY */ #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 */ #else /* CONFIG_SMP */
static inline void smp_send_all_nop(void) { return; } static inline void smp_send_all_nop(void) { return; }

3
arch/parisc/include/asm/thread_info.h
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@ -9,6 +9,9 @@
struct thread_info { struct thread_info {
unsigned long flags; /* thread_info flags (see TIF_*) */ unsigned long flags; /* thread_info flags (see TIF_*) */
int preempt_count; /* 0=premptable, <0=BUG; will also serve as bh-counter */ 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) \ #define INIT_THREAD_INFO(tsk) \

5
arch/parisc/kernel/asm-offsets.c
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@ -14,8 +14,6 @@
* Copyright (C) 2003 James Bottomley <jejb at parisc-linux.org> * Copyright (C) 2003 James Bottomley <jejb at parisc-linux.org>
*/ */
#define GENERATING_ASM_OFFSETS /* asm/smp.h */
#include <linux/types.h> #include <linux/types.h>
#include <linux/sched.h> #include <linux/sched.h>
#include <linux/thread_info.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_TI_FLAGS, offsetof(struct task_struct, thread_info.flags));
DEFINE(TASK_STACK, offsetof(struct task_struct, stack)); DEFINE(TASK_STACK, offsetof(struct task_struct, stack));
#ifdef CONFIG_SMP
DEFINE(TASK_CPU, offsetof(struct task_struct, cpu));
#endif
BLANK(); BLANK();
DEFINE(TASK_REGS, offsetof(struct task_struct, thread.regs)); DEFINE(TASK_REGS, offsetof(struct task_struct, thread.regs));
DEFINE(TASK_PT_PSW, offsetof(struct task_struct, thread.regs.gr[ 0])); DEFINE(TASK_PT_PSW, offsetof(struct task_struct, thread.regs.gr[ 0]));

2
arch/parisc/kernel/smp.c
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@ -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); const struct cpuinfo_parisc *p = &per_cpu(cpu_data, cpuid);
long timeout; long timeout;
idle->cpu = cpuid;
/* Let _start know what logical CPU we're booting /* Let _start know what logical CPU we're booting
** (offset into init_tasks[],cpu_data[]) ** (offset into init_tasks[],cpu_data[])
*/ */