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: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 3e36614..fe99af4 100644 (file)
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -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;
 }
 

diff --git a/include/linux/mmiotrace.h b/include/linux/mmiotrace.h
index 139d7c8..3d1b7bd 100644 (file)
--- a/include/linux/mmiotrace.h
+++ b/include/linux/mmiotrace.h
@@ -1,5 +1,5 @@
-#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 */
-       void *private;
+       /* 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)
 {
@@ -63,28 +79,28 @@ static inline int mmiotrace_printk(const char *fmt, ...)
 #endif /* CONFIG_MMIOTRACE */
 
 enum mm_io_opcode {
-       MMIO_READ = 0x1,     /* struct mmiotrace_rw */
-       MMIO_WRITE = 0x2,    /* struct mmiotrace_rw */
-       MMIO_PROBE = 0x3,    /* struct mmiotrace_map */
-       MMIO_UNPROBE = 0x4,  /* struct mmiotrace_map */
-       MMIO_UNKNOWN_OP = 0x5, /* struct mmiotrace_rw */
+       MMIO_READ       = 0x1,  /* struct mmiotrace_rw */
+       MMIO_WRITE      = 0x2,  /* struct mmiotrace_rw */
+       MMIO_PROBE      = 0x3,  /* struct mmiotrace_map */
+       MMIO_UNPROBE    = 0x4,  /* struct mmiotrace_map */
+       MMIO_UNKNOWN_OP = 0x5,  /* struct mmiotrace_rw */
 };
 
 struct mmiotrace_rw {
-       resource_size_t phys;   /* PCI address of register */
-       unsigned long value;
-       unsigned long pc;       /* optional program counter */
-       int map_id;
-       unsigned char opcode;   /* one of MMIO_{READ,WRITE,UNKNOWN_OP} */
-       unsigned char width;    /* size of register access in bytes */
+       resource_size_t phys;   /* PCI address of register */
+       unsigned long   value;
+       unsigned long   pc;     /* optional program counter */
+       int             map_id;
+       unsigned char   opcode; /* one of MMIO_{READ,WRITE,UNKNOWN_OP} */
+       unsigned char   width;  /* size of register access in bytes */
 };
 
 struct mmiotrace_map {
-       resource_size_t phys;   /* base address in PCI space */
-       unsigned long virt;     /* base virtual address */
-       unsigned long len;      /* mapping size */
-       int map_id;
-       unsigned char opcode;   /* MMIO_PROBE or MMIO_UNPROBE */
+       resource_size_t phys;   /* base address in PCI space */
+       unsigned long   virt;   /* base virtual address */
+       unsigned long   len;    /* mapping size */
+       int             map_id;
+       unsigned char   opcode; /* MMIO_PROBE or MMIO_UNPROBE */
 };
 
 /* in kernel/trace/trace_mmiotrace.c */
@@ -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 */