In commit 2214c0e77259 ("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@xxxxxxxxxxxx>
Fixes: bcf9033e5449 ("sched: move CPU field back into thread_info if THREAD_INFO_IN_TASK=y")
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
---
arch/parisc/include/asm/smp.h | 19 ++-----------------
arch/parisc/include/asm/thread_info.h | 2 ++
arch/parisc/kernel/asm-offsets.c | 4 +---
arch/parisc/kernel/smp.c | 2 +-
4 files changed, 6 insertions(+), 21 deletions(-)
diff --git a/arch/parisc/include/asm/smp.h b/arch/parisc/include/asm/smp.h
index 16d41127500e..cba55abf7bac 100644
--- a/arch/parisc/include/asm/smp.h
+++ b/arch/parisc/include/asm/smp.h
@@ -34,23 +34,8 @@ extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);
#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
+#define raw_smp_processor_id() (current_thread_info()->cpu)
+
#else /* CONFIG_SMP */
static inline void smp_send_all_nop(void) { return; }
diff --git a/arch/parisc/include/asm/thread_info.h b/arch/parisc/include/asm/thread_info.h
index 75657c2c54e1..d6268834bfa5 100644
--- a/arch/parisc/include/asm/thread_info.h
+++ b/arch/parisc/include/asm/thread_info.h
@@ -8,12 +8,14 @@
struct thread_info {
unsigned long flags; /* thread_info flags (see TIF_*) */
+ __u32 cpu; /* current CPU */
int preempt_count; /* 0=premptable, <0=BUG; will also serve as bh-counter */
};
#define INIT_THREAD_INFO(tsk) \
{ \
.flags = 0, \
+ .cpu = 0, \
.preempt_count = INIT_PREEMPT_COUNT, \
}
diff --git a/arch/parisc/kernel/asm-offsets.c b/arch/parisc/kernel/asm-offsets.c
index e35154035441..629d38e36e22 100644
--- a/arch/parisc/kernel/asm-offsets.c
+++ b/arch/parisc/kernel/asm-offsets.c
@@ -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>
@@ -40,7 +38,7 @@ 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));
+ DEFINE(TASK_CPU, offsetof(struct task_struct, thread_info.cpu));
#endif
BLANK();
DEFINE(TASK_REGS, offsetof(struct task_struct, thread.regs));
diff --git a/arch/parisc/kernel/smp.c b/arch/parisc/kernel/smp.c
index 171925285f3e..0cd97fa004c5 100644
--- a/arch/parisc/kernel/smp.c
+++ b/arch/parisc/kernel/smp.c
@@ -339,7 +339,7 @@ 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;
+ task_thread_info(idle)->cpu = cpuid;
/* Let _start know what logical CPU we're booting
** (offset into init_tasks[],cpu_data[])
--
2.30.2
