To fetch a pending channel report word (crw) we use a kernel thread which triggers stcrw and sleeps on a semaphore. The s390 machine check handler uses crw_handle_channel_report to handle one crw if needed. This patch replaces the semaphore with a waitqueue (to block the kernel thread) and an atomic_t (to count the number of pending requests). By this we achieve the ability to force this thread to check for a pending crw (independent on when it is triggered by the machine check handler) and wait for this action to finish. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
		
			
				
	
	
		
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			69 lines
		
	
	
	
		
			2 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 *   Data definitions for channel report processing
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 *    Copyright IBM Corp. 2000,2009
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 *    Author(s): Ingo Adlung <adlung@de.ibm.com>,
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 *		 Martin Schwidefsky <schwidefsky@de.ibm.com>,
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 *		 Cornelia Huck <cornelia.huck@de.ibm.com>,
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 *		 Heiko Carstens <heiko.carstens@de.ibm.com>,
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 */
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#ifndef _ASM_S390_CRW_H
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#define _ASM_S390_CRW_H
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#include <linux/types.h>
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/*
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 * Channel Report Word
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 */
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struct crw {
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	__u32 res1 :  1;   /* reserved zero */
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	__u32 slct :  1;   /* solicited */
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	__u32 oflw :  1;   /* overflow */
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	__u32 chn  :  1;   /* chained */
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	__u32 rsc  :  4;   /* reporting source code */
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	__u32 anc  :  1;   /* ancillary report */
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	__u32 res2 :  1;   /* reserved zero */
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	__u32 erc  :  6;   /* error-recovery code */
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	__u32 rsid : 16;   /* reporting-source ID */
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} __attribute__ ((packed));
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typedef void (*crw_handler_t)(struct crw *, struct crw *, int);
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extern int crw_register_handler(int rsc, crw_handler_t handler);
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extern void crw_unregister_handler(int rsc);
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extern void crw_handle_channel_report(void);
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void crw_wait_for_channel_report(void);
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#define NR_RSCS 16
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#define CRW_RSC_MONITOR  0x2  /* monitoring facility */
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#define CRW_RSC_SCH	 0x3  /* subchannel */
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#define CRW_RSC_CPATH	 0x4  /* channel path */
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#define CRW_RSC_CONFIG	 0x9  /* configuration-alert facility */
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#define CRW_RSC_CSS	 0xB  /* channel subsystem */
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#define CRW_ERC_EVENT	 0x00 /* event information pending */
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#define CRW_ERC_AVAIL	 0x01 /* available */
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#define CRW_ERC_INIT	 0x02 /* initialized */
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#define CRW_ERC_TERROR	 0x03 /* temporary error */
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#define CRW_ERC_IPARM	 0x04 /* installed parm initialized */
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#define CRW_ERC_TERM	 0x05 /* terminal */
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#define CRW_ERC_PERRN	 0x06 /* perm. error, fac. not init */
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#define CRW_ERC_PERRI	 0x07 /* perm. error, facility init */
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#define CRW_ERC_PMOD	 0x08 /* installed parameters modified */
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static inline int stcrw(struct crw *pcrw)
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{
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	int ccode;
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	asm volatile(
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		"	stcrw	0(%2)\n"
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		"	ipm	%0\n"
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		"	srl	%0,28\n"
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		: "=d" (ccode), "=m" (*pcrw)
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		: "a" (pcrw)
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		: "cc" );
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	return ccode;
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}
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#endif /* _ASM_S390_CRW_H */
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