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Commit 9e57fb35 authored by Pekka Paalanen's avatar Pekka Paalanen Committed by Ingo Molnar
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x86 mmiotrace: implement mmiotrace_printk() 



Offer mmiotrace users a function to inject markers from inside the kernel.
This depends on the trace_vprintk() patch.

Signed-off-by: default avatarPekka Paalanen <pq@iki.fi>
Acked-by: default avatarSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 801fe400

arch/x86/mm/mmio-mod.c

+18 −1
Original line number Diff line number Diff line
@@ -75,7 +75,7 @@ static LIST_HEAD(trace_list); /* struct remap_trace */ 
 *   and trace_lock.

 * - Routines depending on is_enabled() must take trace_lock.

 * - trace_list users must hold trace_lock.

 * - is_enabled() guarantees that mmio_trace_record is allowed.

 * - is_enabled() guarantees that mmio_trace_{rw,mapping} are allowed.

 * - pre/post callbacks assume the effect of is_enabled() being true.

 */
@@ -379,6 +379,23 @@ void mmiotrace_iounmap(volatile void __iomem *addr) 
		iounmap_trace_core(addr);

}



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

{

	int ret = 0;

	va_list args;

	unsigned long flags;

	va_start(args, fmt);



	spin_lock_irqsave(&trace_lock, flags);

	if (is_enabled())

		ret = mmio_trace_printk(fmt, args);

	spin_unlock_irqrestore(&trace_lock, flags);



	va_end(args);

	return ret;

}

EXPORT_SYMBOL(mmiotrace_printk);



static void clear_trace_list(void)

{

	struct remap_trace *trace;

arch/x86/mm/testmmiotrace.c

+4 −0
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ 
 */

#include <linux/module.h>

#include <linux/io.h>

#include <linux/mmiotrace.h>



#define MODULE_NAME "testmmiotrace"
@@ -13,6 +14,7 @@ MODULE_PARM_DESC(mmio_address, "Start address of the mapping of 16 kB."); 
static void do_write_test(void __iomem *p)

{

	unsigned int i;

	mmiotrace_printk("Write test.\n");

	for (i = 0; i < 256; i++)

		iowrite8(i, p + i);

	for (i = 1024; i < (5 * 1024); i += 2)
@@ -24,6 +26,7 @@ static void do_write_test(void __iomem *p) 
static void do_read_test(void __iomem *p)

{

	unsigned int i;

	mmiotrace_printk("Read test.\n");

	for (i = 0; i < 256; i++)

		ioread8(p + i);

	for (i = 1024; i < (5 * 1024); i += 2)
@@ -39,6 +42,7 @@ static void do_test(void) 
		pr_err(MODULE_NAME ": could not ioremap, aborting.\n");

		return;

	}

	mmiotrace_printk("ioremap returned %p.\n", p);

	do_write_test(p);

	do_read_test(p);

	iounmap(p);

include/linux/mmiotrace.h

+15 −2
Original line number Diff line number Diff line
@@ -34,11 +34,15 @@ 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);



/* Called from ioremap.c */

#ifdef CONFIG_MMIOTRACE

/* Called from ioremap.c */

extern void mmiotrace_ioremap(resource_size_t offset, unsigned long size,

							void __iomem *addr);

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

static inline void mmiotrace_ioremap(resource_size_t offset,

					unsigned long size, void __iomem *addr)
@@ -48,7 +52,15 @@ static inline void mmiotrace_ioremap(resource_size_t offset, 
static inline void mmiotrace_iounmap(volatile void __iomem *addr)

{

}

#endif /* CONFIG_MMIOTRACE_HOOKS */



static inline int mmiotrace_printk(const char *fmt, ...)

				__attribute__ ((format (printf, 1, 0)));



static inline int mmiotrace_printk(const char *fmt, ...)

{

	return 0;

}

#endif /* CONFIG_MMIOTRACE */



enum mm_io_opcode {

	MMIO_READ = 0x1,     /* struct mmiotrace_rw */
@@ -81,5 +93,6 @@ extern void enable_mmiotrace(void); 
extern void disable_mmiotrace(void);

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 */

kernel/trace/trace_mmiotrace.c

+5 −0
Original line number Diff line number Diff line
@@ -335,3 +335,8 @@ void mmio_trace_mapping(struct mmiotrace_map *map) 
	__trace_mmiotrace_map(tr, data, map);

	preempt_enable();

}



int mmio_trace_printk(const char *fmt, va_list args)

{

	return trace_vprintk(0, fmt, args);

}