1 files changed, 71 insertions, 0 deletions

diff --git a/arch/x86/mm/testmmiotrace.c b/arch/x86/mm/testmmiotrace.c
new file mode 100644
index 000000000000..d877c5b423ef
--- /dev/null
+++ b/arch/x86/mm/testmmiotrace.c
@@ -0,0 +1,71 @@
+/*
+ * Written by Pekka Paalanen, 2008 <pq@iki.fi>
+ */
+#include <linux/module.h>
+#include <linux/io.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;
+        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;
+        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;
+        }
+        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");