Create a new macro ipa_assert() to verify that a condition is true. This produces a build-time error if the condition can be evaluated at build time; otherwise __ipa_assert_runtime() is called (described below).
Another macro, ipa_assert_always() verifies that an expression yields true at runtime, and if it does not, reports an error message. When IPA validation is enabled, __ipa_assert_runtime() becomes a call to ipa_assert_always(), resulting in runtime verification of the asserted condition. Otherwise __ipa_assert_runtime() has no effect, so such ipa_assert() calls are effectively ignored. IPA assertion errors will be reported using the IPA device if possible. Signed-off-by: Alex Elder <el...@linaro.org> --- drivers/net/ipa/ipa_assert.h | 50 ++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) create mode 100644 drivers/net/ipa/ipa_assert.h diff --git a/drivers/net/ipa/ipa_assert.h b/drivers/net/ipa/ipa_assert.h new file mode 100644 index 0000000000000..7e5b9d487f69d --- /dev/null +++ b/drivers/net/ipa/ipa_assert.h @@ -0,0 +1,50 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2021 Linaro Ltd. + */ +#ifndef _IPA_ASSERT_H_ +#define _IPA_ASSERT_H_ + +#include <linux/compiler.h> +#include <linux/printk.h> +#include <linux/device.h> + +/* Verify the expression yields true, and fail at build time if possible */ +#define ipa_assert(dev, expr) \ + do { \ + if (__builtin_constant_p(expr)) \ + compiletime_assert(expr, __ipa_failure_msg(expr)); \ + else \ + __ipa_assert_runtime(dev, expr); \ + } while (0) + +/* Report an error if the given expression evaluates to false at runtime */ +#define ipa_assert_always(dev, expr) \ + do { \ + if (unlikely(!(expr))) { \ + struct device *__dev = (dev); \ + \ + if (__dev) \ + dev_err(__dev, __ipa_failure_msg(expr)); \ + else \ + pr_err(__ipa_failure_msg(expr)); \ + } \ + } while (0) + +/* Constant message used when an assertion fails */ +#define __ipa_failure_msg(expr) "IPA assertion failed: " #expr "\n" + +#ifdef IPA_VALIDATION + +/* Only do runtime checks for "normal" assertions if validating the code */ +#define __ipa_assert_runtime(dev, expr) ipa_assert_always(dev, expr) + +#else /* !IPA_VALIDATION */ + +/* "Normal" assertions aren't checked when validation is disabled */ +#define __ipa_assert_runtime(dev, expr) \ + do { (void)(dev); (void)(expr); } while (0) + +#endif /* !IPA_VALIDATION */ + +#endif /* _IPA_ASSERT_H_ */ -- 2.27.0