| 1 | /* |
| 2 | * Written by Pekka Paalanen, 2008-2009 <pq@iki.fi> |
| 3 | */ |
| 4 | |
| 5 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 6 | |
| 7 | #include <linux/module.h> |
| 8 | #include <linux/io.h> |
| 9 | #include <linux/mmiotrace.h> |
| 10 | |
| 11 | static unsigned long mmio_address; |
| 12 | module_param(mmio_address, ulong, 0); |
| 13 | MODULE_PARM_DESC(mmio_address, " Start address of the mapping of 16 kB " |
| 14 | "(or 8 MB if read_far is non-zero)."); |
| 15 | |
| 16 | static unsigned long read_far = 0x400100; |
| 17 | module_param(read_far, ulong, 0); |
| 18 | MODULE_PARM_DESC(read_far, " Offset of a 32-bit read within 8 MB " |
| 19 | "(default: 0x400100)."); |
| 20 | |
| 21 | static unsigned v16(unsigned i) |
| 22 | { |
| 23 | return i * 12 + 7; |
| 24 | } |
| 25 | |
| 26 | static unsigned v32(unsigned i) |
| 27 | { |
| 28 | return i * 212371 + 13; |
| 29 | } |
| 30 | |
| 31 | static void do_write_test(void __iomem *p) |
| 32 | { |
| 33 | unsigned int i; |
| 34 | pr_info("write test.\n"); |
| 35 | mmiotrace_printk("Write test.\n"); |
| 36 | |
| 37 | for (i = 0; i < 256; i++) |
| 38 | iowrite8(i, p + i); |
| 39 | |
| 40 | for (i = 1024; i < (5 * 1024); i += 2) |
| 41 | iowrite16(v16(i), p + i); |
| 42 | |
| 43 | for (i = (5 * 1024); i < (16 * 1024); i += 4) |
| 44 | iowrite32(v32(i), p + i); |
| 45 | } |
| 46 | |
| 47 | static void do_read_test(void __iomem *p) |
| 48 | { |
| 49 | unsigned int i; |
| 50 | unsigned errs[3] = { 0 }; |
| 51 | pr_info("read test.\n"); |
| 52 | mmiotrace_printk("Read test.\n"); |
| 53 | |
| 54 | for (i = 0; i < 256; i++) |
| 55 | if (ioread8(p + i) != i) |
| 56 | ++errs[0]; |
| 57 | |
| 58 | for (i = 1024; i < (5 * 1024); i += 2) |
| 59 | if (ioread16(p + i) != v16(i)) |
| 60 | ++errs[1]; |
| 61 | |
| 62 | for (i = (5 * 1024); i < (16 * 1024); i += 4) |
| 63 | if (ioread32(p + i) != v32(i)) |
| 64 | ++errs[2]; |
| 65 | |
| 66 | mmiotrace_printk("Read errors: 8-bit %d, 16-bit %d, 32-bit %d.\n", |
| 67 | errs[0], errs[1], errs[2]); |
| 68 | } |
| 69 | |
| 70 | static void do_read_far_test(void __iomem *p) |
| 71 | { |
| 72 | pr_info("read far test.\n"); |
| 73 | mmiotrace_printk("Read far test.\n"); |
| 74 | |
| 75 | ioread32(p + read_far); |
| 76 | } |
| 77 | |
| 78 | static void do_test(unsigned long size) |
| 79 | { |
| 80 | void __iomem *p = ioremap_nocache(mmio_address, size); |
| 81 | if (!p) { |
| 82 | pr_err("could not ioremap, aborting.\n"); |
| 83 | return; |
| 84 | } |
| 85 | mmiotrace_printk("ioremap returned %p.\n", p); |
| 86 | do_write_test(p); |
| 87 | do_read_test(p); |
| 88 | if (read_far && read_far < size - 4) |
| 89 | do_read_far_test(p); |
| 90 | iounmap(p); |
| 91 | } |
| 92 | |
| 93 | /* |
| 94 | * Tests how mmiotrace behaves in face of multiple ioremap / iounmaps in |
| 95 | * a short time. We had a bug in deferred freeing procedure which tried |
| 96 | * to free this region multiple times (ioremap can reuse the same address |
| 97 | * for many mappings). |
| 98 | */ |
| 99 | static void do_test_bulk_ioremapping(void) |
| 100 | { |
| 101 | void __iomem *p; |
| 102 | int i; |
| 103 | |
| 104 | for (i = 0; i < 10; ++i) { |
| 105 | p = ioremap_nocache(mmio_address, PAGE_SIZE); |
| 106 | if (p) |
| 107 | iounmap(p); |
| 108 | } |
| 109 | |
| 110 | /* Force freeing. If it will crash we will know why. */ |
| 111 | synchronize_rcu(); |
| 112 | } |
| 113 | |
| 114 | static int __init init(void) |
| 115 | { |
| 116 | unsigned long size = (read_far) ? (8 << 20) : (16 << 10); |
| 117 | |
| 118 | if (mmio_address == 0) { |
| 119 | pr_err("you have to use the module argument mmio_address.\n"); |
| 120 | pr_err("DO NOT LOAD THIS MODULE UNLESS YOU REALLY KNOW WHAT YOU ARE DOING!\n"); |
| 121 | return -ENXIO; |
| 122 | } |
| 123 | |
| 124 | pr_warning("WARNING: mapping %lu kB @ 0x%08lx in PCI address space, " |
| 125 | "and writing 16 kB of rubbish in there.\n", |
| 126 | size >> 10, mmio_address); |
| 127 | do_test(size); |
| 128 | do_test_bulk_ioremapping(); |
| 129 | pr_info("All done.\n"); |
| 130 | return 0; |
| 131 | } |
| 132 | |
| 133 | static void __exit cleanup(void) |
| 134 | { |
| 135 | pr_debug("unloaded.\n"); |
| 136 | } |
| 137 | |
| 138 | module_init(init); |
| 139 | module_exit(cleanup); |
| 140 | MODULE_LICENSE("GPL"); |