include/lib/utils_def.h

/*
 * Copyright (c) 2016-2023, Arm Limited and Contributors. All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#ifndef UTILS_DEF_H
#define UTILS_DEF_H

/* Compute the number of elements in the given array */
#define ARRAY_SIZE(a)				\
	(sizeof(a) / sizeof((a)[0]))

#define IS_POWER_OF_TWO(x)			\
	(((x) & ((x) - 1)) == 0)

#define SIZE_FROM_LOG2_WORDS(n)		(4 << (n))

#define BIT_32(nr)			(U(1) << (nr))
#define BIT_64(nr)			(ULL(1) << (nr))

#ifndef __aarch64__
#define BIT				BIT_32
#else
#define BIT				BIT_64
#endif

/*
 * Create a contiguous bitmask starting at bit position @l and ending at
 * position @h. For example
 * GENMASK_64(39, 21) gives us the 64bit vector 0x000000ffffe00000.
 */
#if defined(__LINKER__) || defined(__ASSEMBLY__)
#define GENMASK_32(h, l) \
	(((0xFFFFFFFF) << (l)) & (0xFFFFFFFF >> (32 - 1 - (h))))

#define GENMASK_64(h, l) \
	((~0 << (l)) & (~0 >> (64 - 1 - (h))))
#else
#define GENMASK_32(h, l) \
	(((~UINT32_C(0)) << (l)) & (~UINT32_C(0) >> (32 - 1 - (h))))

#define GENMASK_64(h, l) \
	(((~UINT64_C(0)) << (l)) & (~UINT64_C(0) >> (64 - 1 - (h))))
#endif

#ifndef __aarch64__
#define GENMASK				GENMASK_32
#else
#define GENMASK				GENMASK_64
#endif

/*
 * This variant of div_round_up can be used in macro definition but should not
 * be used in C code as the `div` parameter is evaluated twice.
 */
#define DIV_ROUND_UP_2EVAL(n, d)	(((n) + (d) - 1) / (d))

#define div_round_up(val, div) __extension__ ({	\
	__typeof__(div) _div = (div);		\
	((val) + _div - (__typeof__(div)) 1) / _div;		\
})

#define MIN(x, y) __extension__ ({	\
	__typeof__(x) _x = (x);		\
	__typeof__(y) _y = (y);		\
	(void)(&_x == &_y);		\
	_x < _y ? _x : _y;		\
})

#define MAX(x, y) __extension__ ({	\
	__typeof__(x) _x = (x);		\
	__typeof__(y) _y = (y);		\
	(void)(&_x == &_y);		\
	_x > _y ? _x : _y;		\
})

/*
 * The round_up() macro rounds up a value to the given boundary in a
 * type-agnostic yet type-safe manner. The boundary must be a power of two.
 * In other words, it computes the smallest multiple of boundary which is
 * greater than or equal to value.
 *
 * round_down() is similar but rounds the value down instead.
 */
#define round_boundary(value, boundary)		\
	((__typeof__(value))((boundary) - 1))

#define round_up(value, boundary)		\
	((((value) - 1) | round_boundary(value, boundary)) + 1)

#define round_down(value, boundary)		\
	((value) & ~round_boundary(value, boundary))

/*
 * Evaluates to 1 if (ptr + inc) overflows, 0 otherwise.
 * Both arguments must be unsigned pointer values (i.e. uintptr_t).
 */
#define check_uptr_overflow(_ptr, _inc)		\
	((_ptr) > (UINTPTR_MAX - (_inc)))

/*
 * Evaluates to 1 if (u32 + inc) overflows, 0 otherwise.
 * Both arguments must be 32-bit unsigned integers (i.e. effectively uint32_t).
 */
#define check_u32_overflow(_u32, _inc) \
	((_u32) > (UINT32_MAX - (_inc)))

/*
 * For those constants to be shared between C and other sources, apply a 'U',
 * 'UL', 'ULL', 'L' or 'LL' suffix to the argument only in C, to avoid
 * undefined or unintended behaviour.
 *
 * The GNU assembler and linker do not support these suffixes (it causes the
 * build process to fail) therefore the suffix is omitted when used in linker
 * scripts and assembler files.
*/
#if defined(__LINKER__) || defined(__ASSEMBLY__)
# define   U(_x)	(_x)
# define  UL(_x)	(_x)
# define ULL(_x)	(_x)
# define   L(_x)	(_x)
# define  LL(_x)	(_x)
#else
# define   U(_x)	(_x##U)
# define  UL(_x)	(_x##UL)
# define ULL(_x)	(_x##ULL)
# define   L(_x)	(_x##L)
# define  LL(_x)	(_x##LL)
#endif

/* Register size of the current architecture. */
#ifndef __aarch64__
#define REGSZ		U(4)
#else
#define REGSZ		U(8)
#endif

/*
 * Test for the current architecture version to be at least the version
 * expected.
 */
#define ARM_ARCH_AT_LEAST(_maj, _min) \
	((ARM_ARCH_MAJOR > (_maj)) || \
	 ((ARM_ARCH_MAJOR == (_maj)) && (ARM_ARCH_MINOR >= (_min))))

/*
 * Import an assembly or linker symbol as a C expression with the specified
 * type
 */
#define IMPORT_SYM(type, sym, name) \
	extern char sym[];\
	static const __attribute__((unused)) type name = (type) sym;

/*
 * When the symbol is used to hold a pointer, its alignment can be asserted
 * with this macro. For example, if there is a linker symbol that is going to
 * be used as a 64-bit pointer, the value of the linker symbol must also be
 * aligned to 64 bit. This macro makes sure this is the case.
 */
#define ASSERT_SYM_PTR_ALIGN(sym) assert(((size_t)(sym) % __alignof__(*(sym))) == 0)

#define COMPILER_BARRIER() __asm__ volatile ("" ::: "memory")

#define INPLACE(regfield, val)						\
	(((val) + UL(0)) << (regfield##_SHIFT))

#define MASK(regfield)							\
	((~0ULL >> (64ULL - (regfield##_WIDTH))) << (regfield##_SHIFT))

#define EXTRACT(regfield, reg) \
	(((reg) & MASK(regfield)) >> (regfield##_SHIFT))

/*
 * Defines member of structure and reserves space
 * for the next member with specified offset.
 */
#define SET_MEMBER(member, start, end)	\
	union {				\
		member;			\
		unsigned char reserved##end[end - start]; \
	}

#define CONCAT(x, y)	x##y
#define CONC(x, y)	CONCAT(x, y)

/* add operation together with checking whether the operation overflowed
 * The result is '*res',
 * return 0 on success and 1 on overflow
 */
#define add_overflow(a, b, res) __builtin_add_overflow((a), (b), (res))

/*
 * Round up a value to align with a given size and
 * check whether overflow happens.
 * The rounduped value is '*res',
 * return 0 on success and 1 on overflow
 */
#define round_up_overflow(v, size, res)                                     \
	(__extension__({                                                    \
		typeof(res) __res = res;                                    \
		typeof(*(__res)) __roundup_tmp = 0;                         \
		typeof(v) __roundup_mask = (typeof(v))(size) - 1;           \
                                                                            \
		add_overflow((v), __roundup_mask, &__roundup_tmp) ?         \
			1 :                                                 \
			(void)(*(__res) = __roundup_tmp & ~__roundup_mask), \
			0;                                                  \
	}))

/*
 * Add a with b, then round up the result to align with a given size and
 * check whether overflow happens.
 * The rounduped value is '*res',
 * return 0 on success and 1 on overflow
 */
#define add_with_round_up_overflow(a, b, size, res)               \
	(__extension__({                                          \
		typeof(a) __a = (a);                              \
		typeof(__a) __add_res = 0;                        \
                                                                  \
		add_overflow((__a), (b), &__add_res)	    ? 1 : \
		round_up_overflow(__add_res, (size), (res)) ? 1 : \
							      0;  \
	}))

#endif /* UTILS_DEF_H */