imr_selftest.c

// SPDX-License-Identifier: GPL-2.0
/*
 * imr_selftest.c -- Intel Isolated Memory Region self-test driver
 *
 * Copyright(c) 2013 Intel Corporation.
 * Copyright(c) 2015 Bryan O'Donoghue <[email protected]>
 *
 * IMR self test. The purpose of this module is to run a set of tests on the
 * IMR API to validate its sanity. We check for overlapping, reserved
 * addresses and setup/teardown sanity.
 *
 */

#include <asm-generic/sections.h>
#include <asm/cpu_device_id.h>
#include <asm/imr.h>
#include <asm/io.h>

#include <linux/init.h>
#include <linux/mm.h>
#include <linux/types.h>

#define SELFTEST KBUILD_MODNAME ": "
/**
 * imr_self_test_result - Print result string for self test.
 *
 * @res:	result code - true if test passed false otherwise.
 * @fmt:	format string.
 * ...		variadic argument list.
 */
static __printf(2, 3)
void __init imr_self_test_result(int res, const char *fmt, ...)
{
	va_list vlist;

	/* Print pass/fail. */
	if (res)
		pr_info(SELFTEST "pass ");
	else
		pr_info(SELFTEST "fail ");

	/* Print variable string. */
	va_start(vlist, fmt);
	vprintk(fmt, vlist);
	va_end(vlist);

	/* Optional warning. */
	WARN(res == 0, "test failed");
}
#undef SELFTEST

/**
 * imr_self_test
 *
 * Verify IMR self_test with some simple tests to verify overlap,
 * zero sized allocations and 1 KiB sized areas.
 *
 */
static void __init imr_self_test(void)
{
	phys_addr_t base  = virt_to_phys(&_text);
	size_t size = virt_to_phys(&__end_rodata) - base;
	const char *fmt_over = "overlapped IMR @ (0x%08lx - 0x%08lx)\n";
	int ret;

	/* Test zero zero. */
	ret = imr_add_range(0, 0, 0, 0);
	imr_self_test_result(ret < 0, "zero sized IMR\n");

	/* Test exact overlap. */
	ret = imr_add_range(base, size, IMR_CPU, IMR_CPU);
	imr_self_test_result(ret < 0, fmt_over, __va(base), __va(base + size));

	/* Test overlap with base inside of existing. */
	base += size - IMR_ALIGN;
	ret = imr_add_range(base, size, IMR_CPU, IMR_CPU);
	imr_self_test_result(ret < 0, fmt_over, __va(base), __va(base + size));

	/* Test overlap with end inside of existing. */
	base -= size + IMR_ALIGN * 2;
	ret = imr_add_range(base, size, IMR_CPU, IMR_CPU);
	imr_self_test_result(ret < 0, fmt_over, __va(base), __va(base + size));

	/* Test that a 1 KiB IMR @ zero with read/write all will bomb out. */
	ret = imr_add_range(0, IMR_ALIGN, IMR_READ_ACCESS_ALL,
			    IMR_WRITE_ACCESS_ALL);
	imr_self_test_result(ret < 0, "1KiB IMR @ 0x00000000 - access-all\n");

	/* Test that a 1 KiB IMR @ zero with CPU only will work. */
	ret = imr_add_range(0, IMR_ALIGN, IMR_CPU, IMR_CPU);
	imr_self_test_result(ret >= 0, "1KiB IMR @ 0x00000000 - cpu-access\n");
	if (ret >= 0) {
		ret = imr_remove_range(0, IMR_ALIGN);
		imr_self_test_result(ret == 0, "teardown - cpu-access\n");
	}

	/* Test 2 KiB works. */
	size = IMR_ALIGN * 2;
	ret = imr_add_range(0, size, IMR_READ_ACCESS_ALL, IMR_WRITE_ACCESS_ALL);
	imr_self_test_result(ret >= 0, "2KiB IMR @ 0x00000000\n");
	if (ret >= 0) {
		ret = imr_remove_range(0, size);
		imr_self_test_result(ret == 0, "teardown 2KiB\n");
	}
}

static const struct x86_cpu_id imr_ids[] __initconst = {
	X86_MATCH_VFM(INTEL_QUARK_X1000, NULL),
	{}
};

/**
 * imr_self_test_init - entry point for IMR driver.
 *
 * return: -ENODEV for no IMR support 0 if good to go.
 */
static int __init imr_self_test_init(void)
{
	if (x86_match_cpu(imr_ids))
		imr_self_test();
	return 0;
}

/**
 * imr_self_test_exit - exit point for IMR code.
 *
 * return:
 */
device_initcall(imr_self_test_init);