Commit b814d41f authored by Ingo Molnar's avatar Ingo Molnar
Browse files

x86, mm: fault.c, simplify kmmio_fault() 



Impact: cleanup

Remove an #ifdef from kmmio_fault() - we can do this by
providing default implementations for is_kmmio_active()
and kmmio_handler(). The compiler optimizes it all away
in the !CONFIG_MMIOTRACE case.

Also, while at it, clean up mmiotrace.h a bit:

 - standard header guards
 - standard vertical spaces for structure definitions

No code changed (both with mmiotrace on and off in the config):

   text	   data	    bss	    dec	    hex	filename
   2947	     12	     12	   2971	    b9b	fault.o.before
   2947	     12	     12	   2971	    b9b	fault.o.after

Cc: Pekka Paalanen <pq@iki.fi>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 121d5d0a

arch/x86/mm/fault.c

+3 −2
Original line number Diff line number Diff line
@@ -55,13 +55,14 @@ enum x86_pf_error_code { 
	PF_INSTR	=		1 << 4,

};



/*

 * (returns 0 if mmiotrace is disabled)

 */

static inline int kmmio_fault(struct pt_regs *regs, unsigned long addr)

{

#ifdef CONFIG_MMIOTRACE

	if (unlikely(is_kmmio_active()))

		if (kmmio_handler(regs, addr) == 1)

			return -1;

#endif

	return 0;

}

include/linux/mmiotrace.h

+47 −31
Original line number Diff line number Diff line 
#ifndef MMIOTRACE_H

#define MMIOTRACE_H

#ifndef _LINUX_MMIOTRACE_H

#define _LINUX_MMIOTRACE_H



#include <linux/types.h>

#include <linux/list.h>
@@ -13,28 +13,34 @@ typedef void (*kmmio_post_handler_t)(struct kmmio_probe *, 
				unsigned long condition, struct pt_regs *);



struct kmmio_probe {

	struct list_head list; /* kmmio internal list */

	unsigned long addr; /* start location of the probe point */

	unsigned long len; /* length of the probe region */

	kmmio_pre_handler_t pre_handler; /* Called before addr is executed. */

	kmmio_post_handler_t post_handler; /* Called after addr is executed */

	/* kmmio internal list: */

	struct list_head	list;

	/* start location of the probe point: */

	unsigned long		addr;

	/* length of the probe region: */

	unsigned long		len;

	/* Called before addr is executed: */

	kmmio_pre_handler_t	pre_handler;

	/* Called after addr is executed: */

	kmmio_post_handler_t	post_handler;

	void			*private;

};



extern unsigned int kmmio_count;



extern int register_kmmio_probe(struct kmmio_probe *p);

extern void unregister_kmmio_probe(struct kmmio_probe *p);



#ifdef CONFIG_MMIOTRACE

/* kmmio is active by some kmmio_probes? */

static inline int is_kmmio_active(void)

{

	extern unsigned int kmmio_count;

	return kmmio_count;

}



extern int register_kmmio_probe(struct kmmio_probe *p);

extern void unregister_kmmio_probe(struct kmmio_probe *p);



/* Called from page fault handler. */

extern int kmmio_handler(struct pt_regs *regs, unsigned long addr);



#ifdef CONFIG_MMIOTRACE

/* Called from ioremap.c */

extern void mmiotrace_ioremap(resource_size_t offset, unsigned long size,

							void __iomem *addr);
@@ -43,7 +49,17 @@ extern void mmiotrace_iounmap(volatile void __iomem *addr); 
/* For anyone to insert markers. Remember trailing newline. */

extern int mmiotrace_printk(const char *fmt, ...)

				__attribute__ ((format (printf, 1, 2)));

#else

#else /* !CONFIG_MMIOTRACE: */

static inline int is_kmmio_active(void)

{

	return 0;

}



static inline int kmmio_handler(struct pt_regs *regs, unsigned long addr)

{

	return 0;

}



static inline void mmiotrace_ioremap(resource_size_t offset,

					unsigned long size, void __iomem *addr)

{
@@ -94,4 +110,4 @@ extern void mmio_trace_rw(struct mmiotrace_rw *rw); 
extern void mmio_trace_mapping(struct mmiotrace_map *map);

extern int mmio_trace_printk(const char *fmt, va_list args);



#endif /* MMIOTRACE_H */
 
#endif /* _LINUX_MMIOTRACE_H */

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