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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/x86/mm/testmmiotrace.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/x86/mm/testmmiotrace.c')
-rw-r--r-- | arch/x86/mm/testmmiotrace.c | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/arch/x86/mm/testmmiotrace.c b/arch/x86/mm/testmmiotrace.c new file mode 100644 index 000000000..bda73cb7a --- /dev/null +++ b/arch/x86/mm/testmmiotrace.c @@ -0,0 +1,146 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Written by Pekka Paalanen, 2008-2009 <pq@iki.fi> + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/io.h> +#include <linux/mmiotrace.h> +#include <linux/security.h> + +static unsigned long mmio_address; +module_param_hw(mmio_address, ulong, iomem, 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("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("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("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(mmio_address, size); + if (!p) { + pr_err("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); +} + +/* + * Tests how mmiotrace behaves in face of multiple ioremap / iounmaps in + * a short time. We had a bug in deferred freeing procedure which tried + * to free this region multiple times (ioremap can reuse the same address + * for many mappings). + */ +static void do_test_bulk_ioremapping(void) +{ + void __iomem *p; + int i; + + for (i = 0; i < 10; ++i) { + p = ioremap(mmio_address, PAGE_SIZE); + if (p) + iounmap(p); + } + + /* Force freeing. If it will crash we will know why. */ + synchronize_rcu(); +} + +static int __init init(void) +{ + unsigned long size = (read_far) ? (8 << 20) : (16 << 10); + int ret = security_locked_down(LOCKDOWN_MMIOTRACE); + + if (ret) + return ret; + + if (mmio_address == 0) { + pr_err("you have to use the module argument mmio_address.\n"); + pr_err("DO NOT LOAD THIS MODULE UNLESS YOU REALLY KNOW WHAT YOU ARE DOING!\n"); + return -ENXIO; + } + + pr_warn("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); + do_test_bulk_ioremapping(); + pr_info("All done.\n"); + return 0; +} + +static void __exit cleanup(void) +{ + pr_debug("unloaded.\n"); +} + +module_init(init); +module_exit(cleanup); +MODULE_LICENSE("GPL"); |