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Commit d3a73acb authored by Martin Schwidefsky's avatar Martin Schwidefsky
Browse files

s390: split TIF bits into CIF, PIF and TIF bits 



The oi and ni instructions used in entry[64].S to set and clear bits
in the thread-flags are not guaranteed to be atomic in regard to other
CPUs. Split the TIF bits into CPU, pt_regs and thread-info specific
bits. Updates on the TIF bits are done with atomic instructions,
updates on CPU and pt_regs bits are done with non-atomic instructions.

Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent beef560b

arch/s390/include/asm/lowcore.h

+6 −2
Original line number Original line Diff line number Diff line
@@ -93,7 +93,9 @@ struct _lowcore { 
	__u32	save_area_sync[8];		/* 0x0200 */

	__u32	save_area_sync[8];		/* 0x0200 */

	__u32	save_area_async[8];		/* 0x0220 */

	__u32	save_area_async[8];		/* 0x0220 */

	__u32	save_area_restart[1];		/* 0x0240 */

	__u32	save_area_restart[1];		/* 0x0240 */

	__u8	pad_0x0244[0x0248-0x0244];	/* 0x0244 */



	/* CPU flags. */

	__u32	cpu_flags;			/* 0x0244 */





	/* Return psws. */

	/* Return psws. */

	psw_t	return_psw;			/* 0x0248 */

	psw_t	return_psw;			/* 0x0248 */
@@ -237,7 +239,9 @@ struct _lowcore { 
	__u64	save_area_sync[8];		/* 0x0200 */

	__u64	save_area_sync[8];		/* 0x0200 */

	__u64	save_area_async[8];		/* 0x0240 */

	__u64	save_area_async[8];		/* 0x0240 */

	__u64	save_area_restart[1];		/* 0x0280 */

	__u64	save_area_restart[1];		/* 0x0280 */

	__u8	pad_0x0288[0x0290-0x0288];	/* 0x0288 */



	/* CPU flags. */

	__u64	cpu_flags;			/* 0x0288 */





	/* Return psws. */

	/* Return psws. */

	psw_t	return_psw;			/* 0x0290 */

	psw_t	return_psw;			/* 0x0290 */

arch/s390/include/asm/mmu_context.h

+3 −3
Original line number Original line Diff line number Diff line
@@ -36,7 +36,7 @@ static inline void set_user_asce(struct mm_struct *mm) 




	S390_lowcore.user_asce = mm->context.asce_bits | __pa(pgd);

	S390_lowcore.user_asce = mm->context.asce_bits | __pa(pgd);

	set_fs(current->thread.mm_segment);

	set_fs(current->thread.mm_segment);

	set_thread_flag(TIF_ASCE);

	set_cpu_flag(CIF_ASCE);

}

}





static inline void clear_user_asce(void)

static inline void clear_user_asce(void)
@@ -54,7 +54,7 @@ static inline void load_kernel_asce(void) 
	__ctl_store(asce, 1, 1);

	__ctl_store(asce, 1, 1);

	if (asce != S390_lowcore.kernel_asce)

	if (asce != S390_lowcore.kernel_asce)

		__ctl_load(S390_lowcore.kernel_asce, 1, 1);

		__ctl_load(S390_lowcore.kernel_asce, 1, 1);

	set_thread_flag(TIF_ASCE);

	set_cpu_flag(CIF_ASCE);

}

}





static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,

static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
@@ -70,7 +70,7 @@ static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, 
	__ctl_load(S390_lowcore.kernel_asce, 1, 1);

	__ctl_load(S390_lowcore.kernel_asce, 1, 1);

	__ctl_load(S390_lowcore.kernel_asce, 7, 7);

	__ctl_load(S390_lowcore.kernel_asce, 7, 7);

	/* Delay loading of the new ASCE to control registers CR1 & CR7 */

	/* Delay loading of the new ASCE to control registers CR1 & CR7 */

	set_thread_flag(TIF_ASCE);

	set_cpu_flag(CIF_ASCE);

	atomic_inc(&next->context.attach_count);

	atomic_inc(&next->context.attach_count);

	atomic_dec(&prev->context.attach_count);

	atomic_dec(&prev->context.attach_count);

	if (MACHINE_HAS_TLB_LC)

	if (MACHINE_HAS_TLB_LC)

arch/s390/include/asm/processor.h

+22 −0
Original line number Original line Diff line number Diff line
@@ -11,6 +11,13 @@ 
#ifndef __ASM_S390_PROCESSOR_H

#ifndef __ASM_S390_PROCESSOR_H

#define __ASM_S390_PROCESSOR_H

#define __ASM_S390_PROCESSOR_H





#define CIF_MCCK_PENDING	0	/* machine check handling is pending */

#define CIF_ASCE		1	/* user asce needs fixup / uaccess */



#define _CIF_MCCK_PENDING	(1<<CIF_MCCK_PENDING)

#define _CIF_ASCE		(1<<CIF_ASCE)





#ifndef __ASSEMBLY__

#ifndef __ASSEMBLY__





#include <linux/linkage.h>

#include <linux/linkage.h>
@@ -21,6 +28,21 @@ 
#include <asm/setup.h>

#include <asm/setup.h>

#include <asm/runtime_instr.h>

#include <asm/runtime_instr.h>





static inline void set_cpu_flag(int flag)

{

	S390_lowcore.cpu_flags |= (1U << flag);

}



static inline void clear_cpu_flag(int flag)

{

	S390_lowcore.cpu_flags &= ~(1U << flag);

}



static inline int test_cpu_flag(int flag)

{

	return !!(S390_lowcore.cpu_flags & (1U << flag));

}



/*

/*

 * Default implementation of macro that returns current

 * Default implementation of macro that returns current

 * instruction pointer ("program counter").

 * instruction pointer ("program counter").

arch/s390/include/asm/ptrace.h

+22 −0
Original line number Original line Diff line number Diff line
@@ -8,6 +8,12 @@ 




#include <uapi/asm/ptrace.h>

#include <uapi/asm/ptrace.h>





#define PIF_SYSCALL		0	/* inside a system call */

#define PIF_PER_TRAP		1	/* deliver sigtrap on return to user */



#define _PIF_SYSCALL		(1<<PIF_SYSCALL)

#define _PIF_PER_TRAP		(1<<PIF_PER_TRAP)



#ifndef __ASSEMBLY__

#ifndef __ASSEMBLY__





#define PSW_KERNEL_BITS	(PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_ASC_HOME | \

#define PSW_KERNEL_BITS	(PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_ASC_HOME | \
@@ -29,6 +35,7 @@ struct pt_regs 
	unsigned int int_code;

	unsigned int int_code;

	unsigned int int_parm;

	unsigned int int_parm;

	unsigned long int_parm_long;

	unsigned long int_parm_long;

	unsigned long flags;

};

};





/*

/*
@@ -79,6 +86,21 @@ struct per_struct_kernel { 
#define PER_CONTROL_SUSPENSION		0x00400000UL

#define PER_CONTROL_SUSPENSION		0x00400000UL

#define PER_CONTROL_ALTERATION		0x00200000UL

#define PER_CONTROL_ALTERATION		0x00200000UL





static inline void set_pt_regs_flag(struct pt_regs *regs, int flag)

{

	regs->flags |= (1U << flag);

}



static inline void clear_pt_regs_flag(struct pt_regs *regs, int flag)

{

	regs->flags &= ~(1U << flag);

}



static inline int test_pt_regs_flag(struct pt_regs *regs, int flag)

{

	return !!(regs->flags & (1U << flag));

}



/*

/*

 * These are defined as per linux/ptrace.h, which see.

 * These are defined as per linux/ptrace.h, which see.

 */

 */

arch/s390/include/asm/syscall.h

+1 −1
Original line number Original line Diff line number Diff line
@@ -28,7 +28,7 @@ extern const unsigned int sys_call_table_emu[]; 
static inline long syscall_get_nr(struct task_struct *task,

static inline long syscall_get_nr(struct task_struct *task,

				  struct pt_regs *regs)

				  struct pt_regs *regs)

{

{

	return test_tsk_thread_flag(task, TIF_SYSCALL) ?

	return test_pt_regs_flag(regs, PIF_SYSCALL) ?

		(regs->int_code & 0xffff) : -1;

		(regs->int_code & 0xffff) : -1;

}

}