mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-01 07:46:46 +07:00
5ff93697fc
Apparently pages far into an ioremapped region might not actually be mapped during ioremap(). Add an optional read test to try to trigger a multiply faulting MMIO access. Also add more messages to the kernel log to help debugging. This patch is based on a patch suggested by Stuart Bennett <stuart@freedesktop.org> who discovered bugs in mmiotrace related to normal kernel space faults. Signed-off-by: Pekka Paalanen <pq@iki.fi> Cc: Stuart Bennett <stuart@freedesktop.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
120 lines
2.7 KiB
C
120 lines
2.7 KiB
C
/*
|
|
* Written by Pekka Paalanen, 2008-2009 <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 "
|
|
"(or 8 MB if read_far is non-zero).");
|
|
|
|
static unsigned long read_far = 0x400100;
|
|
module_param(read_far, ulong, 0);
|
|
MODULE_PARM_DESC(read_far, " Offset of a 32-bit read within 8 MB "
|
|
"(default: 0x400100).");
|
|
|
|
static unsigned v16(unsigned i)
|
|
{
|
|
return i * 12 + 7;
|
|
}
|
|
|
|
static unsigned v32(unsigned i)
|
|
{
|
|
return i * 212371 + 13;
|
|
}
|
|
|
|
static void do_write_test(void __iomem *p)
|
|
{
|
|
unsigned int i;
|
|
pr_info(MODULE_NAME ": write test.\n");
|
|
mmiotrace_printk("Write test.\n");
|
|
|
|
for (i = 0; i < 256; i++)
|
|
iowrite8(i, p + i);
|
|
|
|
for (i = 1024; i < (5 * 1024); i += 2)
|
|
iowrite16(v16(i), p + i);
|
|
|
|
for (i = (5 * 1024); i < (16 * 1024); i += 4)
|
|
iowrite32(v32(i), p + i);
|
|
}
|
|
|
|
static void do_read_test(void __iomem *p)
|
|
{
|
|
unsigned int i;
|
|
unsigned errs[3] = { 0 };
|
|
pr_info(MODULE_NAME ": read test.\n");
|
|
mmiotrace_printk("Read test.\n");
|
|
|
|
for (i = 0; i < 256; i++)
|
|
if (ioread8(p + i) != i)
|
|
++errs[0];
|
|
|
|
for (i = 1024; i < (5 * 1024); i += 2)
|
|
if (ioread16(p + i) != v16(i))
|
|
++errs[1];
|
|
|
|
for (i = (5 * 1024); i < (16 * 1024); i += 4)
|
|
if (ioread32(p + i) != v32(i))
|
|
++errs[2];
|
|
|
|
mmiotrace_printk("Read errors: 8-bit %d, 16-bit %d, 32-bit %d.\n",
|
|
errs[0], errs[1], errs[2]);
|
|
}
|
|
|
|
static void do_read_far_test(void __iomem *p)
|
|
{
|
|
pr_info(MODULE_NAME ": read far test.\n");
|
|
mmiotrace_printk("Read far test.\n");
|
|
|
|
ioread32(p + read_far);
|
|
}
|
|
|
|
static void do_test(unsigned long size)
|
|
{
|
|
void __iomem *p = ioremap_nocache(mmio_address, size);
|
|
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);
|
|
if (read_far && read_far < size - 4)
|
|
do_read_far_test(p);
|
|
iounmap(p);
|
|
}
|
|
|
|
static int __init init(void)
|
|
{
|
|
unsigned long size = (read_far) ? (8 << 20) : (16 << 10);
|
|
|
|
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 %lu kB @ 0x%08lx in PCI "
|
|
"address space, and writing 16 kB of rubbish in there.\n",
|
|
size >> 10, mmio_address);
|
|
do_test(size);
|
|
pr_info(MODULE_NAME ": All done.\n");
|
|
return 0;
|
|
}
|
|
|
|
static void __exit cleanup(void)
|
|
{
|
|
pr_debug(MODULE_NAME ": unloaded.\n");
|
|
}
|
|
|
|
module_init(init);
|
|
module_exit(cleanup);
|
|
MODULE_LICENSE("GPL");
|