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linux/include/asm-s390/processor.h
Martin Schwidefsky 951f22d5b1 [PATCH] s390: spin lock retry 
Split spin lock and r/w lock implementation into a single try which is done
inline and an out of line function that repeatedly tries to get the lock
before doing the cpu_relax().  Add a system control to set the number of
retries before a cpu is yielded.

The reason for the spin lock retry is that the diagnose 0x44 that is used to
give up the virtual cpu is quite expensive.  For spin locks that are held only
for a short period of time the costs of the diagnoses outweights the savings
for spin locks that are held for a longer timer.  The default retry count is
1000.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-27 16:26:04 -07:00

345 lines
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/*
* include/asm-s390/processor.h
*
* S390 version
* Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
* Author(s): Hartmut Penner (hp@de.ibm.com),
* Martin Schwidefsky (schwidefsky@de.ibm.com)
*
* Derived from "include/asm-i386/processor.h"
* Copyright (C) 1994, Linus Torvalds
*/
#ifndef __ASM_S390_PROCESSOR_H
#define __ASM_S390_PROCESSOR_H
#include <asm/page.h>
#include <asm/ptrace.h>
#ifdef __KERNEL__
/*
* Default implementation of macro that returns current
* instruction pointer ("program counter").
*/
#define current_text_addr() ({ void *pc; __asm__("basr %0,0":"=a"(pc)); pc; })
/*
* CPU type and hardware bug flags. Kept separately for each CPU.
* Members of this structure are referenced in head.S, so think twice
* before touching them. [mj]
*/
typedef struct
{
unsigned int version : 8;
unsigned int ident : 24;
unsigned int machine : 16;
unsigned int unused : 16;
} __attribute__ ((packed)) cpuid_t;
struct cpuinfo_S390
{
cpuid_t cpu_id;
__u16 cpu_addr;
__u16 cpu_nr;
unsigned long loops_per_jiffy;
unsigned long *pgd_quick;
#ifdef __s390x__
unsigned long *pmd_quick;
#endif /* __s390x__ */
unsigned long *pte_quick;
unsigned long pgtable_cache_sz;
};
extern void print_cpu_info(struct cpuinfo_S390 *);
/* Lazy FPU handling on uni-processor */
extern struct task_struct *last_task_used_math;
/*
* User space process size: 2GB for 31 bit, 4TB for 64 bit.
*/
#ifndef __s390x__
# define TASK_SIZE (0x80000000UL)
# define TASK_UNMAPPED_BASE (TASK_SIZE / 2)
# define DEFAULT_TASK_SIZE (0x80000000UL)
#else /* __s390x__ */
# define TASK_SIZE (test_thread_flag(TIF_31BIT) ? \
(0x80000000UL) : (0x40000000000UL))
# define TASK_UNMAPPED_BASE (TASK_SIZE / 2)
# define DEFAULT_TASK_SIZE (0x40000000000UL)
#endif /* __s390x__ */
#define HAVE_ARCH_PICK_MMAP_LAYOUT
typedef struct {
__u32 ar4;
} mm_segment_t;
/*
* Thread structure
*/
struct thread_struct {
s390_fp_regs fp_regs;
unsigned int acrs[NUM_ACRS];
unsigned long ksp; /* kernel stack pointer */
unsigned long user_seg; /* HSTD */
mm_segment_t mm_segment;
unsigned long prot_addr; /* address of protection-excep. */
unsigned int error_code; /* error-code of last prog-excep. */
unsigned int trap_no;
per_struct per_info;
/* Used to give failing instruction back to user for ieee exceptions */
unsigned long ieee_instruction_pointer;
/* pfault_wait is used to block the process on a pfault event */
unsigned long pfault_wait;
};
typedef struct thread_struct thread_struct;
/*
* Stack layout of a C stack frame.
*/
#ifndef __PACK_STACK
struct stack_frame {
unsigned long back_chain;
unsigned long empty1[5];
unsigned long gprs[10];
unsigned int empty2[8];
};
#else
struct stack_frame {
unsigned long empty1[5];
unsigned int empty2[8];
unsigned long gprs[10];
unsigned long back_chain;
};
#endif
#define ARCH_MIN_TASKALIGN 8
#ifndef __s390x__
# define __SWAPPER_PG_DIR __pa(&swapper_pg_dir[0]) + _SEGMENT_TABLE
#else /* __s390x__ */
# define __SWAPPER_PG_DIR __pa(&swapper_pg_dir[0]) + _REGION_TABLE
#endif /* __s390x__ */
#define INIT_THREAD {{0,{{0},{0},{0},{0},{0},{0},{0},{0},{0},{0}, \
{0},{0},{0},{0},{0},{0}}}, \
{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, \
sizeof(init_stack) + (unsigned long) &init_stack, \
__SWAPPER_PG_DIR, \
{0}, \
0,0,0, \
(per_struct) {{{{0,}}},0,0,0,0,{{0,}}}, \
0, 0 \
}
/*
* Do necessary setup to start up a new thread.
*/
#ifndef __s390x__
#define start_thread(regs, new_psw, new_stackp) do { \
regs->psw.mask = PSW_USER_BITS; \
regs->psw.addr = new_psw | PSW_ADDR_AMODE; \
regs->gprs[15] = new_stackp ; \
} while (0)
#else /* __s390x__ */
#define start_thread(regs, new_psw, new_stackp) do { \
regs->psw.mask = PSW_USER_BITS; \
regs->psw.addr = new_psw; \
regs->gprs[15] = new_stackp; \
} while (0)
#define start_thread31(regs, new_psw, new_stackp) do { \
regs->psw.mask = PSW_USER32_BITS; \
regs->psw.addr = new_psw; \
regs->gprs[15] = new_stackp; \
} while (0)
#endif /* __s390x__ */
/* Forward declaration, a strange C thing */
struct task_struct;
struct mm_struct;
/* Free all resources held by a thread. */
extern void release_thread(struct task_struct *);
extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
/* Prepare to copy thread state - unlazy all lazy status */
#define prepare_to_copy(tsk) do { } while (0)
/*
* Return saved PC of a blocked thread.
*/
extern unsigned long thread_saved_pc(struct task_struct *t);
/*
* Print register of task into buffer. Used in fs/proc/array.c.
*/
extern char *task_show_regs(struct task_struct *task, char *buffer);
extern void show_registers(struct pt_regs *regs);
extern void show_trace(struct task_struct *task, unsigned long *sp);
unsigned long get_wchan(struct task_struct *p);
#define __KSTK_PTREGS(tsk) ((struct pt_regs *) \
((unsigned long) tsk->thread_info + THREAD_SIZE - sizeof(struct pt_regs)))
#define KSTK_EIP(tsk) (__KSTK_PTREGS(tsk)->psw.addr)
#define KSTK_ESP(tsk) (__KSTK_PTREGS(tsk)->gprs[15])
/*
* Give up the time slice of the virtual PU.
*/
#ifndef __s390x__
# define cpu_relax() asm volatile ("diag 0,0,68" : : : "memory")
#else /* __s390x__ */
# define cpu_relax() \
do { \
if (MACHINE_HAS_DIAG44) \
asm volatile ("diag 0,0,68" : : : "memory"); \
} while (0)
#endif /* __s390x__ */
/*
* Set PSW to specified value.
*/
static inline void __load_psw(psw_t psw)
{
#ifndef __s390x__
asm volatile ("lpsw 0(%0)" : : "a" (&psw), "m" (psw) : "cc" );
#else
asm volatile ("lpswe 0(%0)" : : "a" (&psw), "m" (psw) : "cc" );
#endif
}
/*
* Set PSW mask to specified value, while leaving the
* PSW addr pointing to the next instruction.
*/
static inline void __load_psw_mask (unsigned long mask)
{
unsigned long addr;
psw_t psw;
psw.mask = mask;
#ifndef __s390x__
asm volatile (
" basr %0,0\n"
"0: ahi %0,1f-0b\n"
" st %0,4(%1)\n"
" lpsw 0(%1)\n"
"1:"
: "=&d" (addr) : "a" (&psw), "m" (psw) : "memory", "cc" );
#else /* __s390x__ */
asm volatile (
" larl %0,1f\n"
" stg %0,8(%1)\n"
" lpswe 0(%1)\n"
"1:"
: "=&d" (addr) : "a" (&psw), "m" (psw) : "memory", "cc" );
#endif /* __s390x__ */
}
/*
* Function to stop a processor until an interruption occurred
*/
static inline void enabled_wait(void)
{
__load_psw_mask(PSW_BASE_BITS | PSW_MASK_IO | PSW_MASK_EXT |
PSW_MASK_MCHECK | PSW_MASK_WAIT | PSW_DEFAULT_KEY);
}
/*
* Function to drop a processor into disabled wait state
*/
static inline void disabled_wait(unsigned long code)
{
unsigned long ctl_buf;
psw_t dw_psw;
dw_psw.mask = PSW_BASE_BITS | PSW_MASK_WAIT;
dw_psw.addr = code;
/*
* Store status and then load disabled wait psw,
* the processor is dead afterwards
*/
#ifndef __s390x__
asm volatile (" stctl 0,0,0(%2)\n"
" ni 0(%2),0xef\n" /* switch off protection */
" lctl 0,0,0(%2)\n"
" stpt 0xd8\n" /* store timer */
" stckc 0xe0\n" /* store clock comparator */
" stpx 0x108\n" /* store prefix register */
" stam 0,15,0x120\n" /* store access registers */
" std 0,0x160\n" /* store f0 */
" std 2,0x168\n" /* store f2 */
" std 4,0x170\n" /* store f4 */
" std 6,0x178\n" /* store f6 */
" stm 0,15,0x180\n" /* store general registers */
" stctl 0,15,0x1c0\n" /* store control registers */
" oi 0x1c0,0x10\n" /* fake protection bit */
" lpsw 0(%1)"
: "=m" (ctl_buf)
: "a" (&dw_psw), "a" (&ctl_buf), "m" (dw_psw) : "cc" );
#else /* __s390x__ */
asm volatile (" stctg 0,0,0(%2)\n"
" ni 4(%2),0xef\n" /* switch off protection */
" lctlg 0,0,0(%2)\n"
" lghi 1,0x1000\n"
" stpt 0x328(1)\n" /* store timer */
" stckc 0x330(1)\n" /* store clock comparator */
" stpx 0x318(1)\n" /* store prefix register */
" stam 0,15,0x340(1)\n" /* store access registers */
" stfpc 0x31c(1)\n" /* store fpu control */
" std 0,0x200(1)\n" /* store f0 */
" std 1,0x208(1)\n" /* store f1 */
" std 2,0x210(1)\n" /* store f2 */
" std 3,0x218(1)\n" /* store f3 */
" std 4,0x220(1)\n" /* store f4 */
" std 5,0x228(1)\n" /* store f5 */
" std 6,0x230(1)\n" /* store f6 */
" std 7,0x238(1)\n" /* store f7 */
" std 8,0x240(1)\n" /* store f8 */
" std 9,0x248(1)\n" /* store f9 */
" std 10,0x250(1)\n" /* store f10 */
" std 11,0x258(1)\n" /* store f11 */
" std 12,0x260(1)\n" /* store f12 */
" std 13,0x268(1)\n" /* store f13 */
" std 14,0x270(1)\n" /* store f14 */
" std 15,0x278(1)\n" /* store f15 */
" stmg 0,15,0x280(1)\n" /* store general registers */
" stctg 0,15,0x380(1)\n" /* store control registers */
" oi 0x384(1),0x10\n" /* fake protection bit */
" lpswe 0(%1)"
: "=m" (ctl_buf)
: "a" (&dw_psw), "a" (&ctl_buf),
"m" (dw_psw) : "cc", "0", "1");
#endif /* __s390x__ */
}
/*
* CPU idle notifier chain.
*/
#define CPU_IDLE 0
#define CPU_NOT_IDLE 1
struct notifier_block;
int register_idle_notifier(struct notifier_block *nb);
int unregister_idle_notifier(struct notifier_block *nb);
#endif
#endif /* __ASM_S390_PROCESSOR_H */
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