linux/arch/x86/mm/testmmiotrace.c
Pekka Paalanen 9e57fb35d7 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: Pekka Paalanen <pq@iki.fi>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-14 10:37:11 +02:00

76 lines
1.7 KiB
C

/*
* Written by Pekka Paalanen, 2008 <pq@iki.fi>
*/
#include <linux/module.h>
#include <linux/io.h>
#include <linux/mmiotrace.h>
#define MODULE_NAME "testmmiotrace"
static unsigned long mmio_address;
module_param(mmio_address, ulong, 0);
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)
iowrite16(i * 12 + 7, p + i);
for (i = (5 * 1024); i < (16 * 1024); i += 4)
iowrite32(i * 212371 + 13, p + i);
}
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)
ioread16(p + i);
for (i = (5 * 1024); i < (16 * 1024); i += 4)
ioread32(p + i);
}
static void do_test(void)
{
void __iomem *p = ioremap_nocache(mmio_address, 0x4000);
if (!p) {
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);
}
static int __init init(void)
{
if (mmio_address == 0) {
pr_err(MODULE_NAME ": you have to use the module argument "
"mmio_address.\n");
pr_err(MODULE_NAME ": DO NOT LOAD THIS MODULE UNLESS"
" YOU REALLY KNOW WHAT YOU ARE DOING!\n");
return -ENXIO;
}
pr_warning(MODULE_NAME ": WARNING: mapping 16 kB @ 0x%08lx "
"in PCI address space, and writing "
"rubbish in there.\n", mmio_address);
do_test();
return 0;
}
static void __exit cleanup(void)
{
pr_debug(MODULE_NAME ": unloaded.\n");
}
module_init(init);
module_exit(cleanup);
MODULE_LICENSE("GPL");