--- /dev/null
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2013 Mauro Carvalho Chehab <mchehab+redhat@kernel.org>
+ * Copyright (c) 2016, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef __TYPES_H
+#define __TYPES_H
+
+#include <asm/bitsperlong.h>
+#include <assert.h>
+#include <linux/bits.h>
+#include <stdint.h>
+
+#define STR(x) #x
+
+/* Please keep the macros as much as possible alined with Linux Kernel ones */
+
+/*
+ * Force a compilation error if condition is true, but also produce a
+ * result (of value 0 and type int), so the expression can be used
+ * e.g. in a structure initializer (or where-ever else comma expressions
+ * aren't permitted).
+ */
+#define BUILD_BUG_ON_ZERO(e) ((int)(sizeof(struct { int:(-!!(e)); })))
+
+/* Are two types/vars the same type (ignoring qualifiers)? */
+#define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
+
+/* &a[0] degrades to a pointer: a different type from an array */
+#define __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))
+
+/*
+ * This returns a constant expression while determining if an argument is
+ * a constant expression, most importantly without evaluating the argument.
+ * Glory to Martin Uecker <Martin.Uecker@med.uni-goettingen.de>
+ *
+ * Details:
+ * - sizeof() return an integer constant expression, and does not evaluate
+ * the value of its operand; it only examines the type of its operand.
+ * - The results of comparing two integer constant expressions is also
+ * an integer constant expression.
+ * - The first literal "8" isn't important. It could be any literal value.
+ * - The second literal "8" is to avoid warnings about unaligned pointers;
+ * this could otherwise just be "1".
+ * - (long)(x) is used to avoid warnings about 64-bit types on 32-bit
+ * architectures.
+ * - The C Standard defines "null pointer constant", "(void *)0", as
+ * distinct from other void pointers.
+ * - If (x) is an integer constant expression, then the "* 0l" resolves
+ * it into an integer constant expression of value 0. Since it is cast to
+ * "void *", this makes the second operand a null pointer constant.
+ * - If (x) is not an integer constant expression, then the second operand
+ * resolves to a void pointer (but not a null pointer constant: the value
+ * is not an integer constant 0).
+ * - The conditional operator's third operand, "(int *)8", is an object
+ * pointer (to type "int").
+ * - The behavior (including the return type) of the conditional operator
+ * ("operand1 ? operand2 : operand3") depends on the kind of expressions
+ * given for the second and third operands. This is the central mechanism
+ * of the macro:
+ * - When one operand is a null pointer constant (i.e. when x is an integer
+ * constant expression) and the other is an object pointer (i.e. our
+ * third operand), the conditional operator returns the type of the
+ * object pointer operand (i.e. "int *"). Here, within the sizeof(), we
+ * would then get:
+ * sizeof(*((int *)(...)) == sizeof(int) == 4
+ * - When one operand is a void pointer (i.e. when x is not an integer
+ * constant expression) and the other is an object pointer (i.e. our
+ * third operand), the conditional operator returns a "void *" type.
+ * Here, within the sizeof(), we would then get:
+ * sizeof(*((void *)(...)) == sizeof(void) == 1
+ * - The equality comparison to "sizeof(int)" therefore depends on (x):
+ * sizeof(int) == sizeof(int) (x) was a constant expression
+ * sizeof(int) != sizeof(void) (x) was not a constant expression
+ */
+#define __is_constexpr(x) \
+ (sizeof(int) == sizeof(*(8 ? ((void *)((long)(x) * 0l)) : (int *)8)))
+
+/**
+ * ARRAY_SIZE - get the number of elements in array @arr
+ * @arr: array to be sized
+ */
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]) + __must_be_array(arr))
+
+/* BIT handling */
+
+#define _AC(X,Y) (X##Y)
+
+#define _UL(x) (_AC(x, UL))
+#define _ULL(x) (_AC(x, ULL))
+
+#define GENMASK_INPUT_CHECK(h, l) \
+ (BUILD_BUG_ON_ZERO(__builtin_choose_expr( \
+ __is_constexpr((l) > (h)), (l) > (h), 0)))
+
+#define GENMASK(h, l) \
+ (GENMASK_INPUT_CHECK(h, l) + __GENMASK(h, l))
+#define GENMASK_ULL(h, l) \
+ (GENMASK_INPUT_CHECK(h, l) + __GENMASK_ULL(h, l))
+
+#define BIT(nr) (_UL(1) << (nr))
+#define BIT_ULL(nr) (_ULL(1) << (nr))
+
+/* Useful constants */
+
+#define MAX_PATH 1024
+#define SZ_512 0x200
+
+/**
+ * container_of - cast a member of a structure out to the containing structure
+ * @ptr: the pointer to the member.
+ * @type: the type of the container struct this is embedded in.
+ * @member: the name of the member within the struct.
+ *
+ * WARNING: any const qualifier of @ptr is lost.
+ */
+#define container_of(ptr, type, member) ({ \
+ void *__mptr = (void *)(ptr); \
+ static_assert(__same_type(*(ptr), ((type *)0)->member) || \
+ __same_type(*(ptr), void), \
+ "pointer type mismatch in container_of()"); \
+ ((type *)(__mptr - offsetof(type, member))); })
+
+#endif
projects / users / mchehab / rasdaemon.git / commitdiff